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Freedman, Joshua N., David J. Collins, Oliver J. Gurney-Champion, Jamie R. McClelland, Simeon Nill, Uwe Oelfke, Martin O. Leach, and Andreas Wetscherek. "Super-resolution T2-weighted 4D MRI for image guided radiotherapy." Radiotherapy and Oncology 129, no. 3 (December 2018): 486–93. http://dx.doi.org/10.1016/j.radonc.2018.05.015.
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Dooley, Sarah, Ricardo LLorente, Kolton Jones, John Ford, and Eric Mellon. "RTHP-22. EDEMA PROGRESSION DURING MRI-GUIDED GLIOBLASTOMA RADIOTHERAPY." Neuro-Oncology 21, Supplement_6 (November 2019): vi214. http://dx.doi.org/10.1093/neuonc/noz175.893.
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Abstract PURPOSE Despite the common finding of pseudoprogression or true progression one month after primary chemoradiotherapy for glioblastoma, there are few studies evaluating brain MRI changes that occur during concurrent chemotherapy and radiotherapy (RT). With the first generation combination MRI-RT device, daily predominantly T2-weighted MRIs are obtained of glioblastoma during RT. We quantified how many patients had significant MRI detectable volumetric changes through the six week course of primary chemoradiotherapy. This is of particular importance since glioblastoma RT is only planned at the beginning of therapy and not commonly re-planned for changes during therapy. METHODS We retrospectively reviewed the daily set-up imaging of 8 patients at our institution who received RT for glioblastoma using the Cobalt-60 MRI-RT system. Patients received standard chemoradiation at 60 Gy in 30 fractions with temozolomide per EORTC22981/26981. We contoured the abnormality on the initial ViewRay setup scan and the set-up scan for fraction 30. After rigid fusion of the contours of the initial setup MRI and fraction 30 MRI, the volumes were compared. RESULTS Of the 8 patients, 3 patients (37.5%) demonstrated edema expansion greater than 5 mm. The maximum distances of T2-weighted abnormality volume growth for these patients were 1.0 cm, 1.5 cm, and 4.1 cm. These findings were correlated with the post-treatment diagnostic MRIs at 3–4 weeks which demonstrated similar FLAIR abnormalities and expansion in T1 with gadolinium contrast volumes within these areas of the radiotherapy fields (pseudoprogression vs. true progression). CONCLUSION Review of MRIs obtained by daily MRI-RT for glioblastoma indicates that 3 of 8 patients had over 5 mm of change in T2-weighted dimensions from beginning to end of radiotherapy. Groups using limited CTV margins for treatment planning should be aware that MRI volumes could significantly increase during radiotherapy.
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Lu, Yu, Peng Zhang, Lihao Lin, Xuan Gao, Yifei Zhou, Jing Feng, and Hongjie Zhang. "Ultra-small bimetallic phosphides for dual-modal MRI imaging guided photothermal ablation of tumors." Dalton Transactions 51, no. 11 (2022): 4423–28. http://dx.doi.org/10.1039/d1dt03898b.
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Zhao, Ying, Yang Liu, Yinghui Wang, Bo Xu, Songtao Zhang, Jianhua Liu, Tianqi Zhang, Longhai Jin, Shuyan Song, and Hongjie Zhang. "Correction: Rapidly clearable MnCo2O4@PAA as novel nanotheranostic agents for T1/T2 bimodal MRI imaging-guided photothermal therapy." Nanoscale 13, no. 48 (2021): 20703. http://dx.doi.org/10.1039/d1nr90222a.
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Correction for ‘Rapidly clearable MnCo2O4@PAA as novel nanotheranostic agents for T1/T2 bimodal MRI imaging-guided photothermal therapy’ by Ying Zhao et al., Nanoscale, 2021, 13, 16251–16257, DOI: 10.1039/D1NR04067G.
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Zhang, Hao, Yaodong Chen, Yunyu Cai, Jun Liu, Pengfei Liu, Zizhuo Li, Tingting An, Xiuhua Yang, and Changhao Liang. "Paramagnetic CuS hollow nanoflowers for T2-FLAIR magnetic resonance imaging-guided thermochemotherapy of cancer." Biomaterials Science 7, no. 1 (2019): 409–18. http://dx.doi.org/10.1039/c8bm01412d.
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Valles, Francisco, Massimo S. Fiandaca, Jamie L. Eberling, Philip A. Starr, Paul S. Larson, Chadwick W. Christine, John Forsayeth, et al. "Qualitative Imaging of Adeno-Associated Virus Serotype 2–Human Aromatic L-Amino Acid Decarboxylase Gene Therapy in a Phase I Study for the Treatment of Parkinson Disease." Neurosurgery 67, no. 5 (November 1, 2010): 1377–85. http://dx.doi.org/10.1227/neu.0b013e3181f53a5c.
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Abstract BACKGROUND: Putaminal convection-enhanced delivery (CED) of an adeno-associated virus serotype 2 (AAV2) vector, containing the human aromatic L-amino acid decarboxylase (hAADC) gene for the treatment of Parkinson disease (PD), has completed a phase I clinical trial. OBJECTIVE: To retrospectively analyze magnetic resonance imaging (MRI) and positron emission tomography (PET) data from the phase I trial, correlate those data with similar nonhuman primate (NHP) data, and present how such information may improve future PD gene therapy trials in preparation for the initiation of the phase II trial. METHODS: Ten patients with PD had been treated with bilateral MRI-guided putaminal infusions of AAV2-hAADC. MRI and PET scans were obtained at baseline (before vector administration) and at various intervals after treatment. Three normal adult NHPs received similar infusions into the thalamus. Imaging studies for both groups are presented, as well as hAADC immunohistochemistry for the NHPs. RESULTS: Early post-CED MRI confirmed the stereotactic targeting accuracy and revealed T2 hyperintensity around the distal cannula tracts, best seen within 4 hours of surgery. Coregistration of post-CED MRI and PET scans revealed increased PET uptake at the sites of T2 hyperintensity. Similar T2 hyperintensities in NHP MRI correlated with hAADC immunohistochemistry. CONCLUSION: Our analysis confirms the correct targeting of the CED cannula tracts within the target human putamen. Coregistration of MRI and PET confirms colocalization of T2 hyperintensities and increased PET uptake around the distal cannula tracts. Because PET uptake closely correlates with hAADC transgene expression and NHP data confirm this relationship between T2 hyperintensity and hAADC immunohistochemistry, we believe that T2-weighted MRI allows visualization of a significant part of the distribution volume of the hAADC gene therapy. Recommendations for future protocols based on these data are presented.
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Lu, Wei, Yuxuan Liao, Chunzhu Jiang, Ruoming Wang, Xueru Shan, Qian Chen, Guoying Sun, and Jianhua Liu. "Polydopamine-coated NaGdF4:Dy for T1/T2-weighted MRI/CT multimodal imaging-guided photothermal therapy." New Journal of Chemistry 43, no. 19 (2019): 7371–78. http://dx.doi.org/10.1039/c9nj00561g.
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Cho, Hyung Ji, Sung Hun Kim, Bong Joo Kang, Hanna Kim, Byung Joo Song, and Ah Won Lee. "Leiomyoma of the nipple diagnosed by MRI." Acta Radiologica Short Reports 1, no. 9 (October 2012): 1–4. http://dx.doi.org/10.1258/arsr.2012.120025.
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Leiomyoma of the nipple is a rare, benign, non-epithelial tumor that is thought to arise from smooth muscle fibers in the subareolar tissue of the breast. We report an unusual case of leiomyoma of the nipple in a 32-year-old woman in whom the diagnosis was made by ultrasound-guided core needle biopsy. She came to our hospital complaining of a recently enlarged nipple with discharge and erosion in the region of the left nipple-areolar complex. This mass was evaluated by mammography, ultrasonography, and magnetic resonance imaging (MRI). To the best of our knowledge, this is the first case of a leiomyoma of the nipple examined by MRI. MRI showed an oval mass with circumscribed margins that appeared as an intermediate signal intensity on both T1- and T2-weighted images. A dynamic MRI study showed a rim-enhancing oval mass with delayed persistent enhancement. Ultrasound-guided core needle biopsy revealed spindle cell proliferation consistent with leiomyoma of the nipple.
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Tamura, Ryo, Katsunori Kashima, Mina Asatani, Koji Nishino, Nobumichi Nishikawa, Masayuki Sekine, Takehiro Serikawa, and Takayuki Enomoto. "Preoperative Ultrasound-Guided Needle Biopsy of 63 Uterine Tumors Having High Signal Intensity Upon T2-Weighted Magnetic Resonance Imaging." International Journal of Gynecologic Cancer 24, no. 6 (July 2014): 1042–47. http://dx.doi.org/10.1097/igc.0000000000000189.
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ObjectiveThe differential diagnosis between uterine sarcoma and benign leiomyoma is difficult when made only by magnetic resonance imaging (MRI); it usually requires an additional preoperative diagnostic procedure. We report our results using ultrasound-guided needle biopsy for these types of uterine tumors.MethodsUltrasound-guided needle biopsy was performed on 63 patients with uterine smooth muscle tumors suspected of malignancy by MRI. We compared the results of presurgical biopsy against the postsurgical pathology of the tumor.ResultsAmong 63 patients with a high signal intensity of the uterine tumor on T2-weighted MRI (1 case was undetermined), 12 cases (19.3%) were diagnosed by the needle biopsy as malignant, and 51 cases (80.6%) were benign. Among the 12 diagnosed as malignant tumors, 11 had surgery performed, and one was treated with chemotherapy. Among the 51 patients diagnosed with a benign tumor, 27 had surgery performed, and 24 were put on a wait-and-see clinical follow-up schedule. One of the 27 surgical patients with a benign tumor had a postsurgical diagnosis of a low-grade endometrial stromal sarcoma. In the 38 cases where surgery was performed, we found the sensitivity, specificity, and the positive and negative predictive values of the needle biopsy were 91.7%, 100%, 100%, and 96.2%, respectively.ConclusionsUltrasound-guided needle biopsy may be a reliable preoperative diagnostic procedure for uterine tumors with suspected malignancy.
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Luo, Shun, Shuijie Qin, Gerile Oudeng, and Li Zhang. "Iron-Based Hollow Nanoplatforms for Cancer Imaging and Theranostics." Nanomaterials 12, no. 17 (August 31, 2022): 3023. http://dx.doi.org/10.3390/nano12173023.
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Over the past decade, iron (Fe)-based hollow nanoplatforms (Fe-HNPs) have attracted increasing attention for cancer theranostics, due to their high safety and superior diagnostic/therapeutic features. Specifically, Fe-involved components can serve as magnetic resonance imaging (MRI) contrast agents (CAs) and Fenton-like/photothermal/magnetic hyperthermia (MTH) therapy agents, while the cavities are able to load various small molecules (e.g., fluorescent dyes, chemotherapeutic drugs, photosensitizers, etc.) to allow multifunctional all-in-one theranostics. In this review, the recent advances of Fe-HNPs for cancer imaging and treatment are summarized. Firstly, the use of Fe-HNPs in single T1-weighted MRI and T2-weighted MRI, T1-/T2-weighted dual-modal MRI as well as other dual-modal imaging modalities are presented. Secondly, diverse Fe-HNPs, including hollow iron oxide (IO) nanoparticles (NPs), hollow matrix-supported IO NPs, hollow Fe-complex NPs and hollow Prussian blue (PB) NPs are described for MRI-guided therapies. Lastly, the potential clinical obstacles and implications for future research of these hollow Fe-based nanotheranostics are discussed.
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Thiruchelvam, Paul, Daniel Leff, and Neil Upadhyay. "Abstract P3-01-17: Mri study of a novel paramagnetic seed for clinically occult breast tumor localization." Cancer Research 82, no. 4_Supplement (February 15, 2022): P3–01–17—P3–01–17. http://dx.doi.org/10.1158/1538-7445.sabcs21-p3-01-17.
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Abstract IntroductionWire localisation (WL) has been the standard of care for clinically occult breast tumorlocalisation since the 1970s. Whilst WL remained reliable, well tolerated and cost effectivethey were often painful and required close coordination of radiological and theatrescheduling. As a result, alternative localization techniques have been developed and arenow widely adopted. Neoadjuvant Chemotherapy (NACT) has enabled de-escalation inaxillary management (Targeted Axillary Dissection) and may facilitate increased breastconserving surgery. This requires localization prior to commencement of NACT. Magseed® isa small (1mm x 5mm) paramagnetic seed that has been used in both the breast and axillarylesion localization setting. It is however MRI conditional, and has a notable MRI artifact(4cm).AimA single institution study aiming to quantify the MRI artifact of a novel paramagnetic seed,the Magseed Biopsy®, which may be used prior to NACT enabling MRI follow-up.Materials and MethodMRI was performed using 1.5 and 3T MRI machines for T1, T2 and VIBE Dixon sequences.For each MRI sequence, the degree of susceptibility artifact was determined. Artifactdimensions were annotated and recorded.ResultsTable 1: Magseed Biopsy Max artifact at 3TVIBE DIXONT1 Non contrast, non fat T2 Non contrast nonsaturatedfat saturatedAxialSagittalAxialSagittalAxialSagittalMagsee 12mm6mm13mm7mm14mm6mmd BiopsyTable 2: Magseed Biopsy Max artifact at 1.5TVIBE DIXONT1 Non contrast, non fat T2 non contrast nonsaturatedfat saturatedAxialSagittalAxialSagittalAxialSagittal. Magseed 12mm7mm12mm6mm13mm7mmBiopsyImage: Magseed Biopsy 1.5T T2 Weighted MRIDiscussionNACT is increasingly utilised to downstage both the breast and the axilla. In some healthcareinstitutions, MRI is a preferred method to follow the progress of NACT treatment. Usingnon-wire guided technology it is sometimes preferable to place a seed at the time of biopsyand the significant artifact from historical Magnetic seed technology has, until now,precluded this option. This review of the MRI data from a novel iteration of magnetictechnology, Magseed Biopsy®, shows a maximum artifact of 14mm in the axial plane on 3TMRI, with less signal void still using 1.5T and other parameters.Based on this data we feel it is possible to use Magseed Biopsy® at the time of biopsy inpatients having NACT patients. This is the first description of this novel paramagnetic seed inan MRI setting, and we will be undertaking further research comparing imaging with othernon-wire guided technologies available.ConclusionThis novel paramagnetic technology produces a significantly reduced MRI artifact comparedto previous Magseeds, enabling placement at time of biopsy in those patients undergoingNACT. Citation Format: Paul Thiruchelvam, Daniel Leff, Neil Upadhyay. Mri study of a novel paramagnetic seed for clinically occult breast tumor localization [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-01-17.
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Zhou, Xi, Xiaolin Lv, Wen Zhao, Tiantian Zhou, Shupeng Zhang, Zhan Shi, Shefang Ye, Lei Ren, and Zhiwei Chen. "Porous MnFe2O4-decorated PB nanocomposites: a new theranostic agent for boosted T1/T2 MRI-guided synergistic photothermal/magnetic hyperthermia." RSC Advances 8, no. 33 (2018): 18647–55. http://dx.doi.org/10.1039/c8ra02946f.
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We synthesized a new theranostic agent of porous MnFe2O4-decorated PB nanocomposites for boosted T1/T2 MRI-guided synergistic photothermal/magnetic hyperthermia.
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Morsi, Amr M., Avital Gazial-Sovran, Hana Baig, Robert S. Kerbel, John Golfinos, Youssef Zaim Wadghiri, and Eva Hernando. "Newmouse models of melanoma metastasis and differences in brain tropism and metastatic growth pattern." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): e19015-e19015. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.e19015.
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e19015 Background: 75% of patients with metastatic melanoma develop brain metastases (B-mets). Such patients show dismal prognosis with a median survival of < 6 months. Scarcity of clinically relevant in vivo models has hindered melanoma B-met studies. We compared the in vivo dissemination upon ultrasound (u/s) guided intracardiac injection of B16F10 cells to 131/4-5B1 (hereafter 5B1), a WM239A subclone with enhanced brain tropism. We also implemented an ex vivo MRI protocol as a high throughput three dimensional approach for characterizing B-mets penetrance and growth. Methods: B16-F10 or 5B1 melanoma cells were injected in C57BL/6J mice (n=40) or athymic/nude mice (n=40) respectively using u/s-guided intracardiac injection. Upon weight loss, mice were euthanized, and heads prepared for ex vivo imaging. All µMRI experiments were performed with a 7T Bruker Avance II console. The protocol consisted of (110-mm)3 isotropic T1-, T2- and T2*-weighted sequences. Results: Our ex vivo MRI recapitulates the clinical radiological T1 and T2 brightening as well as susceptibility-induced T2* darkening effect of melanoma. The B16F10 model revealed exclusive ventricular and leptomeningeal spread while the 5B1 model showed parenchymal lesions. In addition, 90% of the 5B1 mice with brain tumors showed multiple lesions (3-16) vs. 18% in the B16F10 model (1- 3). Finally, 3D volume studies revealed a higher B-met penetrance (68% vs. 18%), delayed onset of tumor detection (earliest-day 27 vs. day 15) post-injection and a slower growth rate of 5B1 brain metastases compared to B16F10 tumors. Conclusions: Our results suggest that u/s-guided intracardiac injection of melanoma cells is an optimal method to capture the cells’ spontaneous dissemination pattern (or site-specific tropism) and that the 5B1 model is a more clinically relevant model of melanoma B-met for preclinical studies.
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Satapathy, Suresh Chandra, and Venkatesan Rajinikanth. "Jaya Algorithm Guided Procedure to Segment Tumor from Brain MRI." Journal of Optimization 2018 (November 14, 2018): 1–12. http://dx.doi.org/10.1155/2018/3738049.
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Brain abnormality is a cause for the chief risk factors in human society with larger morbidity rate. Identification of tumor in its early stage is essential to provide necessary treatment procedure to save the patient. In this work, Jaya Algorithm (JA) and Otsu’s Function (OF) guided method is presented to mine the irregular section of brain MRI recorded with Flair and T2 modality. This work implements a two-step process to examine the brain tumor from the axial, sagittal, and coronal views of the two-dimensional (2D) MRI slices. This paper presents a detailed evaluation of thresholding procedure with varied threshold levels (Th=2,3,4,5), skull stripping process before/after the thresholding practice, and the tumor extraction based on the Chan-Vese approach. Superiority of JA is confirmed among other prominent heuristic approaches found in literature. The outcome of implemented study confirms that Jaya Algorithm guided method is capable of presenting superior values of Jaccard-Index, Dice-Coefficient, sensitivity, specificity, accuracy, and precision on the BRATS 2015 dataset.
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Somford, Diederik Meindert, Caroline M. Hoeks, Roderick C. van den Bergh, Henk Vergunst, Inge M. van Oort, Geert A. Smits, Jorg R. Oddens, et al. "Value of multimodality MRI and MR-guided biopsy at inclusion in an active surveillance protocol for prostate cancer." Journal of Clinical Oncology 30, no. 5_suppl (February 10, 2012): 105. http://dx.doi.org/10.1200/jco.2012.30.5_suppl.105.
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105 Background: To prevent overtreatment of insignificant and/or low-risk prostate carcinoma in the PSA screening era, active surveillance is emerging as a treatment strategy for selected patients. In our series we aim to establish whether MRI could aid in correct risk assessment for these patients within the framework of the Prostate Cancer Research International Active Surveillance (PRIAS) study. Methods: We included patients in our protocol based on contemporary criteria for active surveillance: - Diagnosis of prostate cancer by TRUS-guided biopsy. - PSA ≤10 ng/mL, PSA density <0.2 ng/mL/mL - Clinical stage ≤ T2 - Gleason score (GS) ≤3+3=6 - ≤ 2 biopsy cores with cancer All patients underwent multimodality MRI of the prostate, including T2-weighted, diffusion-weighted and dynamic contrast-enhanced MR sequences. When a tumor-suspicious region (TSR) could be identified a targeted MR-guided biopsy (MRGB) was performed to obtain pathology. Patients were referred for definitive treatment in case of GS > 3+3=6 upon MRGB or T3 stage at MRI. Results: In 48 of 49 included patients at least one TSR was identified, with a median of 2 TSRs (range1-4) per patient. MRGB was obtained from every TSR, with a median of 4 MRGBs taken per patient. Five patients had a GS >3+3=6 upon MRGB and were excluded. Three patients were excluded due to suspicion of T3 stage on MRI. Five patient were excluded upon physician’s discretion due to multifocal prostate cancer upon MRGB. Combined multimodality MRI/MRGB in our active surveillance cohort thus excluded 27% (13/49) of patients who were incorrectly stratified as low-risk prostate carcinoma by contemporary criteria. Conclusions: Application of multimodality MRI and MRGB in an active surveillance protocol improves risk stratification, adding onto contemporary PSA and TRUS-guided biopsy criteria for low-risk prostate cancer. This approach might increase safety and reliability of active surveillance for prostate cancer and deserves ongoing prospective evaluation.
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Hamerschlak, Nelson, Laercio Rosemberg, Alexandre Parma, Fernanda F. Assir, Frederico R. Moreira, Jose R. Parga, Edson Amaro, et al. "Magnetic Ressonance Imaging (MRI) in the Evaluation of Iron Overload in Patients with Beta Thalassaemia. The Brazilian National Program Preliminary Results." Blood 106, no. 11 (November 16, 2005): 3825. http://dx.doi.org/10.1182/blood.v106.11.3825.3825.
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Abstract Magnetic Ressonance Imaging (MRI) using T2 star (T2*) tecnique appears to be a very useful method for monitoring iron overload and iron chelation therapy in thalassaemia. In Brazil, we have around 400 thalassaemic major patients all over the country. They were treated with hipertransfusion protocols and desferroxamine and/or deferiprone chelation. We developed a cooperative program with the Brazilian Thalassaemic Patients Association (ABRASTA) in order to developT2* tecnique in Brazil to submit brazilian patients to an annual iron overload monitoring process with MRI.. We performed the magnetic ressonance T2* using GE equipment (GE, Milwaukee USA), with validation to chemical estimation of iron in patients undergoing liver biopsy. Until now, 60 patients were scanned, median age=23,2 (12–54); gender: 18 male (30%) and 42 female (70%). The median ferritin levels were 2030 ng/ml (Q1=1466; Q3=3296). As other authors described before, there was a curvilinear inverse correlation between iron concentration by biopsy, liver T2*(r=0,92) and also there were a correlation with ferritin levels. We also correlated myocardial iron measured by T2* with ventricular function.. As miocardial iron increased, there was a progressive decline in ejection fraction and no significant correlation was found between miocardial T2* and the ferritin levels. Liver iron content can be predicted by ferritin levels. On the other hand, cardiac disfunction is the most important cause of mortality among thalassaemic patients. Since Miocardio iron content cannot be predicted from serum ferritin or liver iron, and ventricular function can only detect those with advance disease, intensification and combination of chelation therapy, guided by T2* MRI tecnique should reduce mortality from the reversible cardiomyopathy among thalassaemic patients.
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Biradar, Mallinath. "Diagnostic accuracy of Multiparametric MRI in detection of prostate cancer compared with histopathology obtained by MRI directed TRUS guided cognitive fusion biopsy are T2WI, DWI and DCE enough for Indian scenario." MedPulse International Journal of Radiology 20, no. 1 (2021): 10–12. http://dx.doi.org/10.26611/10132013.
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Background: The incidence of prostatic carcinoma is increasing worldwide. With its high resolution, ability to provide excellent tissue characterization and multiplanar imaging capabilities, multi-parametric magnetic resonance imaging (mpMRI) plays a crucial role in detection, local staging and follow-up of carcinoma prostate. It also helps guide targeted biopsies in initial biopsy negative patient. Objectives: Study diagnostic accuracy of mp-MRI and primarily that of the three MR sequences T2, DWI and DCE in detection of prostatic cancer by correlating them with histopathology and thus whether it is feasible for a short MRI of 3 sequences to be used on a large scale in Indian scenario. Materials and Methods: A prospective study was done at a tertiary care hospital between April 2017 to November 2018 in which 50 patients who presented with suspicion of prostate cancer were referred to radiology department for evaluation using MRI. MRIexamination was done using 3T Siemens Magnetom Verio. Followed by this MRI directed TRUS guided cognitive fusion biopsy was done from the prostate. Samples were sent for histopathology. Results: Out of 50 cases studied, 24 cases (48%) were found to be malignant and 26 cases (52 %) were benign on histopathology. In our study, combined T2 + DWI + DCE gave sensitivity of 95.83 %, specificity of 57.69%, positive predictive value of 68.21 % and negative predictive value of 93.75%. Conclusion: Multiparametric MRI using T2, DWI and DCE has a high diagnostic accuracy for evaluation of prostatic cancer.
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Satragno, C., A. Gonnelli, E. Cella, C. Scaffidi, A. Ginulla, M. Tagliamento, N. Giannini, et al. "P03.11.A Potential role of pre-radiotherapy MRI for target delineation in high-grade gliomas: a multicenter retro-prospective cohort study." Neuro-Oncology 24, Supplement_2 (September 1, 2022): ii34—ii35. http://dx.doi.org/10.1093/neuonc/noac174.115.
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Abstract Background The optimal timing for target identification in high-grade glioma (HGG) remains unclear due to variability in the hyper-signal T2/FLAIR between MRI performed at diagnosis, post-surgery and at radiotherapy (RT) start. The aim of this study was to retrospectively confirm that RT planned on delayed MRI might allow to spare more normal tissue without decreasing local tumour control, in order to prospectively evaluate the best standard and advanced MRI and metabolic imaging sequences for clinical tumor volume (CTV) adaptation. Material and Methods We analyzed a retrospective cohort of consecutive patients with HGG treated from 2017 to 2020. All patients had a diagnostic MRI and another performed immediately post-surgery or pre-RT. Target volumes were contoured, based on T2/FLAIR, on diagnostic and post-surgery MRI in group A, while in group B on pre-RT MRI. We analyzed GTV and CTV volume, and the percentage increase between them. Moreover, we compared the two groups in terms of clinical-pathological characteristics and progression-free survival (PFS) and overall survival (OS). A prospective study, started on January 2022, has enrolled patients with HGG evaluated by advanced sequences MRI at diagnosis, post-surgery and pre-RT. In addition, some selected patients have undergone diagnostic DOPA-PET and pre-RT DOPA-PET. 2 MRI-guided contours have been performed for each patient: adapted on T2/FLAIR post-surgery and CTV-adapt on pre-RT, to assess study objectives. Results In retrospective cohort we analyzed 54 patients (25 group A, 29 group B). The median age of patients was 61 years (IQR 17,75), 93% had an ECOG PS of 0 or 1, 51 were symptomatic at diagnosis. Patients in group B had more frequently MGMT methylation (59 % vs. 28%, p=0.01) while less frequently frontal lobe involvement (60% vs. 24%, p=0.01). The median percentage increase between GTV and CTV was higher in group A than B: 431% (range 62%-7335%) vs 385% (range 53%-3174%), respectively. No significant difference in the pattern of relapse was observed, since >90% of disease recurrences were in-field in both groups. Median PFS and OS of the overall population were 9.5 months (95% CI 7 - 12) and 18.5 months (95% CI 16 - 24), respectively. Patients in group B had a significant better PFS as compared to those in group A (p=0.03), but similar OS. Nevertheless, imbalance in MTMT methylation status between the two groups was a major driver for PFS. Overall, 37 out of 51 patients had improvement in neurological symptoms (p<0.001), with no difference between the two groups (p=0.54). Conclusion Our data suggest that CTV adaptation to pre-RT T2/FLAIR may allow reducing RT volume, without affecting symptoms relieving and disease control. Results from the prospective study will help identifying the best adaptation of CTV guided by T2/FLAIR, advanced MRI sequences and metabolic imaging, in order to optimize efficacy and safety of treatment planning.
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Pepe, Alessia, Antonella Meloni, Giuseppe Rossi, Paolo Cianciulli, Anna Spasiano, Domenico D'Ascola, Aurelio Maggio, et al. "Heart T2* for Prediction of Cardiac Complications in Well-Treated TM Patients." Blood 118, no. 21 (November 18, 2011): 1089. http://dx.doi.org/10.1182/blood.v118.21.1089.1089.
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Abstract Abstract 1089 Introduction: T2* Magnetic Resonance Imaging (MRI) technique allows noninvasive quantification of organ-specific iron burden, playing a key role in the management of thalassemia major (TM) patients. There are few data on the incidence of heart failure and arrhythmias in TM patients according to baseline T2* values. The aim of this study was to establish prospectively the risk of cardiac complications in a large cohort of well-treated TM patients. Methods: We considered 527 TM patients (252 males, mean age 30±9) for who clinical data relative to a period of 5 years after the first MRI were collected in a central data base. At time of the first scan mean ferritin levels were1653±1559 ng/l, global heart was 27±13 ms, and excellent/good level of compliance were present in the 96% of the study population. Results: At 5 years of follow-up, we recorded 24 cardiac events: 4 episodes of cardiac failure, 15 of arrhythmia, 1 of pulmonary hypertension and 4 of other cardiac complications. The majority of these events (21/24) happened within the first 24 months subsequent to the MRI, so we considered this follow-up period. At the first MRI scan, in patients with cardiac complications the global heart T2* was 22.5 ±12.4 ms. In comparison with global heart T2* values ≥20 ms, there was not a significantly increased risk of cardiac complications associated with global heart T2* values <20 ms (HR= 2.028 P=0.09) (see figure). In the heart failure patients the global heart T2* was 19±12 ms. In comparison with global heart T2* values ≥20 ms, there was not a significantly increased risk of heart failure associated with global heart T2* values <20 ms (HR=1.9 P=0.524) or <10 ms (HR=2.6 P=0.443). In the arrhythmic patients the global heart T2* was 25±13 ms. In comparison with global heart T2* values ≥20 ms, there was not a significantly increased risk of arrhythmia associated with global heart T2* values <20 ms (HR=2.1 P=0.179) or <10 ms (HR=0.8 P=0.824). During the follow up changes in the chelation therapy (type and/or dose-frequencies) were found in > 25% of the study population. Conclusion: We detected very few cardiac events, almost all concentrated in the first 24 months. In a large cohort of well-treated TM patients heart T2* lost its power in predicting cardiac events probably due to a patient-specific adjustment of the chelation therapy MRI-guided. Disclosures: No relevant conflicts of interest to declare.
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Maurer, Gabriele D., Julia Tichy, Patrick N. Harter, Ulrike Nöth, Lutz Weise, Johanna Quick-Weller, Ralf Deichmann, Joachim P. Steinbach, Oliver Bähr, and Elke Hattingen. "Matching Quantitative MRI Parameters with Histological Features of Treatment-Naïve IDH Wild-Type Glioma." Cancers 13, no. 16 (August 12, 2021): 4060. http://dx.doi.org/10.3390/cancers13164060.
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Quantitative MRI allows to probe tissue properties by measuring relaxation times and may thus detect subtle changes in tissue composition. In this work we analyzed different relaxation times (T1, T2, T2* and T2′) and histological features in 321 samples that were acquired from 25 patients with newly diagnosed IDH wild-type glioma. Quantitative relaxation times before intravenous application of gadolinium-based contrast agent (GBCA), T1 relaxation time after GBCA as well as the relative difference between T1 relaxation times pre-to-post GBCA (T1rel) were compared with histopathologic features such as the presence of tumor cells, cell and vessel density, endogenous markers for hypoxia and cell proliferation. Image-guided stereotactic biopsy allowed for the attribution of each tissue specimen to its corresponding position in the respective relaxation time map. Compared to normal tissue, T1 and T2 relaxation times and T1rel were prolonged in samples containing tumor cells. The presence of vascular proliferates was associated with higher T1rel values. Immunopositivity for lactate dehydrogenase A (LDHA) involved slightly longer T1 relaxation times. However, low T2′ values, suggesting high amounts of deoxyhemoglobin, were found in samples with elevated vessel densities, but not in samples with increased immunopositivity for LDHA. Taken together, some of our observations were consistent with previous findings but the correlation of quantitative MRI and histologic parameters did not confirm all our pathophysiology-based assumptions.
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Lee, Joon Kyu, Chang Liu, Mohamed A. Elshaikh, and Ning Wen. "Multiparametric MRI-based intraprostatic tumor volume delineation in localized prostate cancer." Journal of Clinical Oncology 36, no. 6_suppl (February 20, 2018): 22. http://dx.doi.org/10.1200/jco.2018.36.6_suppl.22.
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22 Background: Multiparametric MR imaging (mpMRI) has shown promising results in the diagnosis and localization of prostate cancer. Furthermore, mpMRI may play an important role in identifying a suitable target volume for intraprostatic radiotherapy boost. We sought to investigate the level of correlation between dominant tumor foci contoured on various mpMRI sequences. Methods: mpMRI data from 18 patients with MR-guided biopsy-proven prostate cancer were obtained from the SPIE-AAPM-NCI Prostate MR Classification Challenge. Each case consisted of T2-weighted, apparent diffusion coefficient (ADC), and ktrans images computed from dynamic contrast-enhanced sequences. All image sets were rigidly co-registered, and the dominant tumor foci were identified and contoured for each MRI sequence. Hausdorff distance (HD), mean distance to agreement (MDA), and Dice and Jaccard coefficients were calculated between the contours for each pair of MRI sequences (i.e., T2 vs. ADC, T2 vs. ktrans, and ADC vs. ktrans). The Pearson correlation coefficient (PCC) was also obtained for Dice and Jaccard between these image pairs. Results: The dominant tumor foci were located in the peripheral zone, transition zone, and anterior fibromuscular stroma in 5 (28%), 7 (39%), and 6 (33%) patients, respectively. Mean tumor volumes in the T2-weighted, ADC, and ktrans sequences were 2.71 +/- 2.74 mL, 2.71 +/- 2.67 mL, and 2.21 +/- 1.86 mL, respectively. Mean HD and MDA were lowest (4.34 +/- 1.52 mm and 1.00 +/- 0.52 mm) and Dice and Jaccard coefficients highest (0.74 +/- 0.12 and 0.60 +/- 0.15) for T2 vs. ADC. The PCC for Dice was 0.15 between T2 vs. ADC and T2 vs. ktrans, 0.37 between T2 vs. ADC and ADC vs. ktrans, and 0.62 between T2 vs. ktrans and ADC vs. ktrans, and similar values were obtained for Jaccard (0.12, 0.32, and 0.67, respectively). Four patients were excluded in the PCC calculation as no vascular permeability was visible in the ktrans maps. Conclusions: This analysis suggests that T2-weighted and ADC sequences have high correlation in identifying a suitable intraprostatic radiotherapy boost volume for localized prostate cancer. Furthermore, ktrans maps may provide additional information for tumor volume delineation.
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Puy, Laurent, Marco Pasi, Mark Rodrigues, Susanne J. van Veluw, Georgios Tsivgoulis, Ashkan Shoamanesh, and Charlotte Cordonnier. "Cerebral microbleeds: from depiction to interpretation." Journal of Neurology, Neurosurgery & Psychiatry 92, no. 6 (February 9, 2021): 598–607. http://dx.doi.org/10.1136/jnnp-2020-323951.
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Cerebral microbleeds (CMBs) are defined as hypointense foci visible on T2*-weighted and susceptible-weighted MRI sequences. CMBs are increasingly recognised with the widespread use of MRI in healthy individuals as well as in the context of cerebrovascular disease or dementia. They can also be encountered in major critical medical conditions such as in patients requiring extracorporeal mechanical oxygenation. The advent of MRI-guided postmortem neuropathological examinations confirmed that, in the context of cerebrovascular disease, the vast majority of CMBs correspond to recent or old microhaemorrhages. Detection of CMBs is highly influenced by MRI parameters, in particular field strength, postprocessing methods used to enhance T2* contrast and three dimensional sequences. Despite recent progress, harmonising imaging parameters across research studies remains necessary to improve cross-study comparisons. CMBs are helpful markers to identify the nature and the severity of the underlying chronic small vessel disease. In daily clinical practice, presence and numbers of CMBs often trigger uncertainty for clinicians especially when antithrombotic treatments and acute reperfusion therapies are discussed. In the present review, we discuss those clinical dilemmas and address the value of CMBs as diagnostic and prognostic markers for future vascular events.
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Cohen-Inbar, O. "OS1 - 136 Time-Delayed Contrast Enhanced MRI Improves Detection of Brain Metastases: A Prospective Validation of Diagnostic Yield." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 43, S4 (October 2016): S1—S2. http://dx.doi.org/10.1017/cjn.2016.332.
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The radiological detection of BMs is essential for optimizing a patient’s treatment. This statement is even more valid when stereotactic radiosurgery (SRS), a non-invasive image guided treatment that can target BM as small as 1-2 mm, is delivered as part of that care. The timing of image acquisition after contrast administration can influence the diagnostic sensitivity of contrast enhanced MRI for BM. Objective: Investigate the effect of time delayed acquisition after administration of intravenous Atavist® (Gadobutrol 1mmol/ml) on the detection of BM. Methods: This is a prospective IRB approved study of 50 patients with BM who underwent post-contrast MRI sequences immediately after injection of 0.1 mmol/kg Gadavist® as part of clinical care (t0), followed by axial T1 sequences after a 10 minutes (t1) and 20 minute delay (t2). MRI studies were blindly compared by 3 neuro-radiologists. Results: Single measure intraclass correlation coefficients were very high (0.914, 0.904 and 0.905 for t0, t1 and t2 respectively), corresponding to a reliable inter-observer correlation. The t2 delayed sequences showed a significant and consistently higher diagnostic sensitivity for BM by every participating neuroradiologist as well as for the entire cohort (p=0.016, p=0.035 and 0.034 respectively). A disproportionately high representation of BM detected on the delayed studies was located within posterior circulation territories (compared to predictions based on tissue volume and blood-flow volumes). Conclusion: Considering the safe and potentially high yield nature of delayed MRI sequences, it should supplement the basic MRI sequences in all patients in need of precise delineation of their intracranial disease.
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Kaganov, Helen, Alex Ades, and David Stuart Fraser. "PREOPERATIVE MAGNETIC RESONANCE IMAGING DIAGNOSTIC FEATURES OF UTERINE LEIOMYOSARCOMAS: A SYSTEMATIC REVIEW." International Journal of Technology Assessment in Health Care 34, no. 2 (2018): 172–79. http://dx.doi.org/10.1017/s0266462318000168.
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Objectives: There are no current established pathognomonic diagnostic features for uterine leiomyosarcomas in the pre- or perioperative setting. Recent inadvertent upstaging of this rare malignancy during laparoscopic morcellation of a presumed fibroid has prompted widespread debate among clinicians regarding the safety of current surgical techniques for management of fibroids. This study aims to conduct a systematic review investigating significant diagnostic features in magnetic resonance imaging (MRI) of uterine leiomyosarcomas.Methods: A comprehensive database search was conducted guided by PRISMA recommendations for peer-reviewed publications to November 2017. Parameters available in MRI were compared for reliability and accuracy of diagnosis of leiomyosarcomas. A decision tree algorithm classifier model was constructed to investigate whether T1 and T2 MRI signal intensities are useful indicators.Results: Nine eligible studies were identified for analysis. There appears to be a significant relationship between histopathological type and T1 and T2 intensity signals (p < .05). A decision tree model analyzing T1 and T2 signal intensity readings supports this trend, with a diagnostic specificity of 77.78 percent for uterine leiomyosarcomas. The apparent diffusion coefficient (ADC) values were not observed to have a significant relationship with tumor pathology (p = .18).Conclusions: Various studies have investigated pre- and perioperative techniques in differentiating uterine leiomyosarcoma from benign fibroids. Given the rarity of the malignancy and lack of pathognomonic diagnostic parameters, there is difficulty in establishing definitive criteria. A decision tree model is proposed to aid diagnosis based on MRI signal intensities.
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Nichols-Vinueza, Diana X., Matthew T. White, Andrew J. Powell, Puja Banka, and Ellis J. Neufeld. "MRI-Guided Iron Assessment and Oral Chelator Use Improve Iron Status In Thalassemia Major Patients: a Six-Year Single Center Retrospective Cohort Study." Blood 122, no. 21 (November 15, 2013): 563. http://dx.doi.org/10.1182/blood.v122.21.563.563.
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Abstract Background Patients (pts) with thalassemia major (TM) require regular red blood cell transfusions. Adequate iron chelation prevents morbidity and mortality due to transfusional iron overload, and must be guided by accurate assessment of tissue iron levels. Magnetic resonance imaging (MRI) can non-invasively measure liver iron content (LIC) and cardiac iron, and has almost entirely supplanted liver biopsy for LIC at our center. The therapeutic goal is to either (a) maintain iron status within a consensus target range, or (b) decrease the iron burden in pts above the target. Three chelators are FDA approved in the US: deferoxamine (DFO), deferasirox (DFX), and deferiprone (DFP), (approval years 1968, 2005 and 2011 respectively). The aim of this study was to evaluate our ability to improve iron status over time in the MRI and oral chelator era. Methods This IRB-approved, single-center, retrospective observational study covered the period from Jan 2005, when MRI iron assessments became standard at our center, to Dec 2012. The study population included all TM pts followed for chelation at our center who had >2 MRI studies during the study period. LIC was measured by calculating T2* and, starting April 2006, also by measuring T2 using the commercial Ferriscan® technique. Liver T2* was converted to LIC using a regression equation (Wood et al. Blood, 2005; 106:1460). Cardiac iron concentration was measured by calculating cT2*; in this abstract both T2* in msec and its reciprocal R2* (1000/cT2* in Hz, which varies proportionally to iron) are reported. The target for LIC was <7 mg/g dry wt (dw), (mean of T2* and Ferriscan LIC) and for cardiac iron, cR2*<50 Hz (i.e. cT2* >20 msec). Statistical analyses were performed in SAS. Results 42 pts (55% male) met the inclusion criteria and had a median age at first MRI of 17.5y (range 1.9-43). Over a mean follow-up period of 5.2±1.9 y, 190 MRIs were performed with median of 4.5 MRIs per pt, interquartile range 3-6. In 2005, DFO was the predominant chelator (70% vs 26% on research use of chelators, DFX; n=27); DFX predominated after its commercial launch. 29/40 (73%) were on DFX by 2009, but this proportion dropped to 23/36 (64%) by 2012. 13/42 pts (31%) remained within the target ranges for cardiac T2* and LIC throughout the study period. 29/42 pts (69%) had at least one cardiac T2* or LIC out of the target range in a total of 97 MRIs. 38/97 (40%) of these out-of-range MRIs prompted a change in chelation strategy: 61% dose change only, 34% change of monotherapy agent, and 5% change from monotherapy to combination. Two pts died of heart failure due to iron overload during the study period; both had taken DFP before their deaths, but for divergent duration (3 days vs 5 y). The median number of chelation changes was 1.4 per pt/y (IQR 0.9-1.9). 175/229 (76%) dosing changes were for iron status as assessed by MRI or ferritin; 7/229 (3%) were dose decreases for side effects, and 2% were due to weight change only. Change in chelators occurred 82 times during the study. 34% of chelator changes were due to low or high iron status by MRI or Ferritin. 11% of changes were for side effects to a prior chelator and 54% were for other reasons (commercial launch of DFX or clinical trials). From initial to final MRI, both LIC and T2* status of our pts improved significantly (figure). At the initial MRI, 16/41 (40%) of pts were in target range for both LIC and cR2*, 4/41 (10%) were in the highest (undesirable) range of LIC>15 mg/g dw, and/or cardiac T2* <10 msec. From first to last cardiac T2* assessment (n=38), 63% of pts started and ended within the target range, 13% improved from abnormal to target range, 24% remained out of the target range. The two pts who died were among the persistent abnormal cardiac T2* group. For LIC (n=42), 45% remained in the target range throughout, 33% started out of target range and ended within, 12% improved but not to the target, 7% worsened, and one outlier remained severe. Conclusions The introduction of routine MRI assessments of LIC and cardiac R2* (T2*), together with the introduction of oral chelators, has improved the fraction of TM pts with liver and cardiac iron within the target range at our center. Annual MRIs facilitate chelation changes when necessary. Legend: A: Cardiac iron status from first to last MRI for each subject. Reciprocal cR2* and cT2* are on left and right Y-axes. B: Liver iron status. P-values are by Wilcoxon signed-rank test. Disclosures: Neufeld: Shire: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Apopharma: Consultancy.
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Pham, Jonathan, Ricky R. Savjani, Yu Gao, Minsong Cao, Peng Hu, Ke Sheng, Daniel A. Low, Michael Steinberg, Amar U. Kishan, and Yingli Yang. "Evaluation of T2-Weighted MRI for Visualization and Sparing of Urethra with MR-Guided Radiation Therapy (MRgRT) On-Board MRI." Cancers 13, no. 14 (July 16, 2021): 3564. http://dx.doi.org/10.3390/cancers13143564.
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Purpose: To evaluate urethral contours from two optimized urethral MRI sequences with an MR-guided radiotherapy system (MRgRT). Methods: Eleven prostate cancer patients were scanned on a MRgRT system using optimized urethral 3D HASTE and 3D TSE. A resident radiation oncologist contoured the prostatic urethra on the patients’ planning CT, diagnostic 3T T2w MRI, and both urethral MRIs. An attending radiation oncologist reviewed/edited the resident’s contours and additionally contoured the prostatic urethra on the clinical planning MRgRT MRI (bSSFP). For each image, the resident radiation oncologist, attending radiation oncologist, and a senior medical physicist qualitatively scored the prostatic urethra visibility. Using MRgRT 3D HASTE-based contouring workflow as baseline, prostatic urethra contours drawn on CT, diagnostic MRI, clinical bSSFP and 3D TSE were evaluated relative to the contour on 3D HASTE using 95th percentile Hausdorff distance (HD95), mean-distance-to-agreement (MDA), and DICE coefficient. Additionally, prostatic urethra contrast-to-noise-ratios (CNR) were calculated for all images. Results: For two out of three observers, the urethra visibility score for 3D HASTE was significantly higher than CT, and clinical bSSFP, but was not significantly different from diagnostic MRI. The mean HD95/MDA/DICE values were 11.35 ± 3.55 mm/5.77 ± 2.69 mm/0.07 ± 0.08 for CT, 7.62 ± 2.75 mm/3.83 ± 1.47 mm/0.12 ± 0.10 for CT + diagnostic MRI, 5.49 ± 2.32 mm/2.18 ± 1.19 mm/0.35 ± 0.19 for 3D TSE, and 6.34 ± 2.89 mm/2.65 ± 1.31 mm/0.21 ± 0.12 for clinical bSSFP. The CNR for 3D HASTE was significantly higher than CT, diagnostic MRI, and clinical bSSFP, but was not significantly different from 3D TSE. Conclusion: The urethra’s visibility scores showed optimized urethral MRgRT 3D HASTE was superior to the other tested methodologies. The prostatic urethra contours demonstrated significant variability from different imaging and workflows. Urethra contouring uncertainty introduced by cross-modality registration and sub-optimal imaging contrast may lead to significant treatment degradation when urethral sparing is implemented to minimize genitourinary toxicity.
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Ken, Soleakhena, Pierre Graff-Cailleaud, Jean-Marc Bachaud, Richard Aziza, Sandra Arnault, Amellie Lusque, Francois-Xavier Arnaud, Thomas Brun, Daniel Portalez, and Bernard Malavaud. "Is multiparametric MRI able to characterize margin for focal brachytherapy in low-grade prostate cancer?" Journal of Clinical Oncology 35, no. 6_suppl (February 20, 2017): e555-e555. http://dx.doi.org/10.1200/jco.2017.35.6_suppl.e555.
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e555 Background: Focal brachytherapy is proposed in our institute as an alternative treatment to active surveillance for low-grade prostate cancer (PCa). This study aims at characterizing the tumor focus and its margin with multiparametric Magnetic Resonance Imaging (mpMRI). Methods: Patients pre-qualified for this study were positive for PCa (Gleason 3+3) on a previous standard biopsy series. New series of mp-MRI-guided and ultrasound-targeted biopsies were performed and in total, 17 patients with confirmed tumor and diameter < 20mm were included in this phase II clinical trial (NCT01902680). mpMRI were acquired on a 1.5T Magnetom Aera Siemens scan. Anatomic imaging consists in Fast Spin Echo T2-weighted MRI (T2-MRI) and functional Diffusion Weighted MRI (DWI-MRI) and Dynamic Contrast Enhanced MRI (DCE-MRI) were also performed. After mpMRI registration, tumor volumes of interest (VOI) were drawn on anatomic T2-MRI. VOI and VOI+2mm were reported on functional DWI-MRI and DCE-MRI. Extracted parameters were Apparent Diffusion Coefficient (ADC) and KTrans. All parameters distributions were analyzed with Olea Sphere v3.0 and compared to contralateral normal appearing tissue. Focal brachytherapy was then delivered to all patients with linked 125I seeds with a dose prescription of 152 Gy on the Planning Target Volume (PTV = VOI+2mm). Results: ADC parameters (mean, meadian, 25th and 75th percentiles) are found to be significantly lower in tumor volume (VOI) compared to contralateral normal tissue (p < 0.012 for all ADC parameters), confirming diffusion tumor mass restriction. Different distributions of ADC and KTrans were observed among patients: majority (66.66%) of low ADC and abnormal KTrans values were included in the VOI but interestingly, the 2mm margin allows us to treat additional abnormal ADC and KTrans volumes on 1/3 of the patients. Conclusions: This study confirms that mpMRI is a non-invasive technique able to characterize tumor margin for focal brachytherapy in low-grade PCa. Target volume margin definition is a hot topic when focal treatments (e.g. cryotherapy or HIFU) are considered and mpMRI can bring quantitative answers. Clinical trial information: NCT01902680.
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Weidner, Artur, Christina Stengl, Fabian Dinkel, Stefan Dorsch, Carlos Murillo, Steffen Seeber, Regula Gnirs, et al. "An abdominal phantom with anthropomorphic organ motion and multimodal imaging contrast for MR-guided radiotherapy." Physics in Medicine & Biology 67, no. 4 (February 11, 2022): 045009. http://dx.doi.org/10.1088/1361-6560/ac4ef8.
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Abstract Purpose. Improvements in image-guided radiotherapy (IGRT) enable accurate and precise treatment of moving tumors in the abdomen while simultaneously sparing healthy tissue. However, the lack of validation tools for newly developed MR-guided radiotherapy hybrid devices such as the MR-Linac is an open issue. This study presents a custom developed abdominal phantom with respiratory organ motion and multimodal imaging contrast to perform end-to-end tests for IGRT treatment planning scenarios. Methods. The abdominal phantom contains deformable and anatomically shaped liver and kidney models made of Ni-DTPA and KCl-doped agarose mixtures that can be reproducibly positioned within the phantom. Organ models are wrapped in foil to avoid ion exchange with the surrounding agarose and to provide stable T1 and T2 relaxation times as well as HU numbers. Breathing motion is realized by a diaphragm connected to an actuator that is hydraulically controlled via a programmable logic controller. With this system, artificial and patient-specific breathing patterns can be carried out. In 1.5 T magnetic resonance imaging (MRI), diaphragm, liver and kidney motion was measured and compared to the breathing motion of a healthy male volunteer for different breathing amplitudes including shallow, normal and deep breathing. Results. The constructed abdominal phantom demonstrated organ-equivalent intensity values in CT as well as in MRI. T1-weighted (T1w) and T2-weighted (T2w) relaxation times for 1.5 T and CT numbers were 552.9 ms, 48.2 ms and 48.8 HU (liver) as well as 950.42 ms, 79 ms and 28.2 HU (kidney), respectively. These values were stable for more than six months. Extracted breathing motion from a healthy volunteer revealed a liver to diaphragm motion ratio (LDMR) of 64.4% and a kidney to diaphragm motion ratio (KDMR) of 30.7%. Well-comparable values were obtained for the phantom (LDMR: 65.5%, KDMR: 27.5%). Conclusions. The abdominal phantom demonstrated anthropomorphic T1 and T2 relaxation times as well as HU numbers and physiological motion pattern in MRI and CT. This allows for wide use in the validation of IGRT including MRgRT.
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MacDonell, Jacquelyn, Niravkumar Patel, Gregory Fischer, E. Clif Burdette, Jiang Qian, Vaibhav Chumbalkar, Goutam Ghoshal, et al. "Robotic Assisted MRI-Guided Interventional Interstitial MR-Guided Focused Ultrasound Ablation in a Swine Model." Neurosurgery 84, no. 5 (June 14, 2018): 1138–48. http://dx.doi.org/10.1093/neuros/nyy266.
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Abstract BACKGROUND Ablative lesions are current treatments for epilepsy and brain tumors. Interstitial magnetic resonance (MR) guided focused ultrasound (iMRgFUS) may be an alternate ablation technique which limits thermal tissue charring as compared to laser therapy (LITT) and can produce larger ablation patterns nearer the surface than transcranial MR guided focused ultrasound (tcMRgFUS). OBJECTIVE To describe our experience with interstitial focused ultrasound (iFUS) ablations in swine, using MR-guided robotically assisted (MRgRA) delivery. METHODS In an initial 3 animals, we optimized the workflow of the robot in the MR suite and made modifications to the robotic arm to allow range of motion. Then, 6 farm pigs (4 acute, 2 survival) underwent 7 iMRgFUS ablations using MRgRA. We altered dosing to explore differences between thermal dosing in brain as compared to other tissues. Imaging was compared to gross examination. RESULTS Our work culminated in adjustments to the MRgRA, iMRgFUS probes, and dosing, culminating in 2 survival surgeries; swine had ablations with no neurological sequelae at 2 wk postprocedure. Immediately following iMRgFUS therapy, diffusion-weighted imaging, and T1 weighted MR were accurate reflections of the ablation volume. T2 and fluid-attenuated inversion-recovery (FLAIR) images were accurate reflections of ablation volume 1-wk postprocedure. CONCLUSION We successfully performed MRgRA iFUS ablation in swine and found intraoperative and postoperative imaging to correlate with histological examination. These data are useful to validate our system and to guide imaging follow-up for thermal ablation lesions in brain tissue from our therapy, tcMRgFUS, and LITT.
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Alkins, Ryan, Yuexi Huang, Dan Pajek, and Kullervo Hynynen. "Cavitation-based third ventriculostomy using MRI-guided focused ultrasound." Journal of Neurosurgery 119, no. 6 (December 2013): 1520–29. http://dx.doi.org/10.3171/2013.8.jns13969.
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Object Transcranial focused ultrasound is increasingly being investigated as a minimally invasive treatment for a range of intracranial pathologies. At higher peak rarefaction pressures than those used for thermal ablation, focused ultrasound can initiate inertial cavitation and create holes in the brain by fractionation of the tissue elements. The authors investigated the technical feasibility of using MRI-guided focused ultrasound to perform a third ventriculostomy as a possible noninvasive alternative to endoscopic third ventriculostomy for hydrocephalus. Methods A craniectomy was performed in male pigs weighing 13–19 kg to expose the supratentorial brain, leaving the dura mater intact. Seven pigs were treated through the craniectomy, while 2 pigs were treated through ex vivo human skulls placed in the beam path. Registration and targeting was done using T2-weighted MRI sequences. For transcranial treatments a CT scan was used to correct the beam from aberrations due to the skull and maintain a small, high-intensity focus. Sonications were performed at both 650 kHz and 230 kHz at a range of intensities, and the in situ pressures were estimated both from simulations and experimental data to establish a threshold for tissue fractionation in the brain. Results In craniectomized animals at 650 kHz, a peak pressure ≥ 22.7 MPa for 1 second was needed to reliably create a ventriculostomy. Transcranially at this frequency the ExAblate 4000 was unable to generate the required intensity to fractionate tissue, although cavitation was initiated. At 230 kHz, ventriculostomy was successful through the skull with a peak pressure of 8.8 MPa. Conclusions This is the first study to suggest that it is possible to perform a completely noninvasive third ventriculostomy using ultrasound. This may pave the way for future studies and eventually provide an alternative means for the creation of CSF communications in the brain, including perforation of the septum pellucidum or intraventricular membranes.
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Altamirano, Jaime Antonio, Ivan Federico Pinto, Roberto Mauricio Vilches, Jorge Gonzalo Diaz, Camilo Sandoval, Alvaro Daniel Vidal, Mauricio Canals, et al. "Diagnostic capability of multiparametric MRI in patients with transrectal prostate biopsy." Journal of Clinical Oncology 34, no. 2_suppl (January 10, 2016): 155. http://dx.doi.org/10.1200/jco.2016.34.2_suppl.155.
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155 Background: The prostatic multiparametric MRI (mpMRI) is the combination of anatomical imaging and functional sequences. Nowadays this technique is still being researched due to its positive published results. The objective of this study is to show our experience in the application of the mpMRI in patients, prior to the TRUS-guided biopsy, and the sensitivity and specificity of its measured parameters and their combination. Methods: Prospective cohort. MpMRI was indicated to patients prior to the TRUS-Guided biopsy. Diffusion, PIRADS, DCE and T2 parameters were observed on the MRIs, and the presence of cancer and Gleason score on the biopsy. Logistic regression test was performed with a 95% confidence interval. We assigned different values, depending of the importance of each factor, applying binominal regression. Results: We registered 73 patients with mpMRI prior to the TRUS-Guided Biopsy, and their results. The cancer detection rate was 60.27% (44 patients). The T2 signal had a sensibility of 81.82% and a specificity of 27.59%, ROC curve 0.54 (CI 0.44 – 0.64). The diffusion has a sensibility of 30% and a specificity of 85.19% with a ROC curve of 0.58 (CI 0.48-0.68). The DCE has a sensibility and specificity of 77.78% and 35.29% respectively, ROC curve of 0.57 (CI 0.42-0.71). By combining the T2, diffusion and DCE parameters, having 2 or more altered values, we obtained a sensibility of 84.62% with a 41.18% specificity, curve of 0.68 (CI 0.54-0.81). The sensitivity and specificity with a PIRADS score ≥ 3 was of 68.42 and 36.36% with a ROC curve of 0.56 (CI 0.36-0.76). With a PIRADS ≥ 4 the sensitivity and specificity was 57.89% and 54.55% respectively. The calculated measured score was assigned as 7 points for altered T2, 8 points for altered diffusion and 5 points for altered DCE. With a total value ≥ 12 the sensitivity of the score was 84.62% with a 41.18% sensitivity, ROC curve 0.68 (CI 0.54-0.81). Conclusions: The use of isolated mpMRI parameters have low performance, whereas this is greatly increased when used combined. The assigned weight of each parameter is a factor to consider and review on the existing scores.
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Germann, Thomas, Marc-André Weber, Burkhard Lehner, Laurent Kintzele, Iris Burkholder, Hans-Ulrich Kauczor, and Christoph Rehnitz. "Intraarticular Osteoid Osteoma: MRI Characteristics and Clinical Presentation Before and After Radiofrequency Ablation Compared to Extraarticular Osteoid Osteoma." RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren 192, no. 12 (July 8, 2020): 1190–99. http://dx.doi.org/10.1055/a-1181-9041.
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Purpose To determine MRI characteristics and the clinical presentation of intraarticular osteoid osteomas (OO) before and after treatment with CT-guided radiofrequency ablation (RFA) compared with extraarticular osteoid osteomas. Materials and Methods In a retrospective study, n = 21 patients with an intraarticular OO were matched with a control group of n = 21 patients with an extraarticular OO at a comparable anatomical position. All patients underwent CT-guided RFA and preinterventional MRI. In n = 31 cases, follow-up MR imaging was available. MR images were analyzed for morphologic features: effusion and synovitis, bone marrow edema (BME), soft tissue edema, periosteal reaction as well as T1 / T2 signal and contrast enhancement of the nidus. Recorded clinical parameters included the initial diagnosis, the course of pain symptoms after RFA and the incidence of complications. Results The nidus was detectable in all patients on MRI. BME had the highest sensitivity in both intra- and extraarticular OO (100 %). Effusion and synovitis were only observed in the intraarticular OO group (n = 21) with a perfect sensitivity and specificity (100 %) and a high negative predictive value (85 %). Soft tissue edema was significantly more present in patients with intraarticular OO (p = 0.0143). No significant differences were present regarding periosteal reaction, T1/T2 signal and contrast enhancement of the nidus (p > 0.05). BME, contrast enhancement, soft tissue edema, periosteal reaction, effusion and synovitis, if preexisting, always decreased after RFA. In 66.7 % of patients with intraarticular OO, a false initial diagnosis was made (extraarticular: 19 %). All patients were free of pain after intervention. Complications following the RFA procedure did not occur. Conclusion MRI demonstrates the nidus and thus the OO in all cases regardless of the location. The characteristic MRI morphology of an intraarticular OO includes synovitis and joint effusion, which are always present and differentiate with perfect sensitivity/specificity from an extraarticular OO. In both intra- and extraarticular OOs pathologic MRI changes at least decreased or completely normalized and the clinical results after RFA were excellent. Key Points: Citation Format
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Li, Jing, Xincong Li, Siman Gong, Cuiting Zhang, Chenggen Qian, Hongzhi Qiao, and Minjie Sun. "Dual-Mode Avocado-like All-Iron Nanoplatform for Enhanced T1/T2 MRI-Guided Cancer Theranostic Therapy." Nano Letters 20, no. 7 (June 24, 2020): 4842–49. http://dx.doi.org/10.1021/acs.nanolett.0c00817.
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Deene, Yves De, and Morgan Wheatley. "Real time 4D Radiation Gel Dosimetry on the Australian MRI-Linac." Journal of Physics: Conference Series 2167, no. 1 (January 1, 2022): 012029. http://dx.doi.org/10.1088/1742-6596/2167/1/012029.
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Abstract 4D radiation dosimetry using a highly radiation-sensitive polymer gel dosimeter with real-time quantitative MRI readout is presented as a technique to acquire the accumulated radiation dose distribution during image guided radiotherapy (IGRT) on an MRI-Linac. Optimized T2 weighted TSE scans are converted into quantitative ΔR2 maps and subsequently to radiation dose maps. The potential of real-time 4D radiation dosimetry in a theragnostic MRI-Linac is demonstrated in test tubes, for a square beam in a cylindrical gel phantom, for a simple step-and-shoot irradiation in a head phantom and a dynamic arc treatment on a cylindrical gel phantom using a rotating couch. The optimal sequence parameters for maximal dose resolution in the dynamic MRI acquisition will be presented and the trade off between MRI scanning speed and dose resolution will be discussed. A further improvement in temporal resolution using a keyhole imaging approach is the focus of future research.
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Partovi, Sasan, Ziang Lu, Lorenna Vidal, Dean A. Nakamoto, Ji Buethe, Michael Coffey, and Indravadan J. Patel. "Real-time MRI-guided percutaneous sclerotherapy treatment of venous low-flow malformations in the head and neck." Phlebology: The Journal of Venous Disease 33, no. 5 (May 18, 2017): 344–52. http://dx.doi.org/10.1177/0268355517710110.
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Purpose This manuscript describes the technique of real-time MRI-guided sclerotherapy for low-flow venous malformations in the head and neck based on our institutional experience. Materials and methods Ethanolamine oleate is used as the sclerosant and is mixed with gadolinium for visualization during the procedure. The five procedural steps include: (I) an initial tri-plane T2-weighted sequence to visualize the lesion; (II) a T1 FSE or trueFISP sequence to assess needle placement and advancement within the lesion; (III) a tri-plane T1 FLASH sequence to monitor sclerosant injection; (IV) a T1 FSE or VIBE sequence to assess sclerosant coverage of the malformation before needle removal; (V) a post-procedural tri-plane T1 fat-saturated sequence to confirm sclerosant coverage of the lesion. Periprocedural medications typically include steroids, antibiotic prophylaxis, and non-steroidal anti-inflammatory medication. Patients are typically admitted for overnight observation. Conclusion Real-time MRI-guided sclerotherapy for low-flow venous malformations in the head and neck is effective and safe.
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Ndode-Ekane, Xavier Ekolle, Riikka Immonen, Elina Hämäläinen, Eppu Manninen, Pedro Andrade, Robert Ciszek, Tomi Paananen, Olli Gröhn, and Asla Pitkänen. "MRI-Guided Electrode Implantation for Chronic Intracerebral Recordings in a Rat Model of Post−Traumatic Epilepsy—Challenges and Gains." Biomedicines 10, no. 9 (September 15, 2022): 2295. http://dx.doi.org/10.3390/biomedicines10092295.
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Brain atrophy induced by traumatic brain injury (TBI) progresses in parallel with epileptogenesis over time, and thus accurate placement of intracerebral electrodes to monitor seizure initiation and spread at the chronic postinjury phase is challenging. We evaluated in adult male Sprague Dawley rats whether adjusting atlas-based electrode coordinates on the basis of magnetic resonance imaging (MRI) increases electrode placement accuracy and the effect of chronic electrode implantations on TBI-induced brain atrophy. One group of rats (EEG cohort) was implanted with two intracortical (anterior and posterior) and a hippocampal electrode right after TBI to target coordinates calculated using a rat brain atlas. Another group (MRI cohort) was implanted with the same electrodes, but using T2-weighted MRI to adjust the planned atlas-based 3D coordinates of each electrode. Histological analysis revealed that the anterior cortical electrode was in the cortex in 83% (25% in targeted layer V) of the EEG cohort and 76% (31%) of the MRI cohort. The posterior cortical electrode was in the cortex in 40% of the EEG cohort and 60% of the MRI cohort. Without MRI-guided adjustment of electrode tip coordinates, 58% of the posterior cortical electrodes in the MRI cohort will be in the lesion cavity, as revealed by simulated electrode placement on histological images. The hippocampal electrode was accurately placed in 82% of the EEG cohort and 86% of the MRI cohort. Misplacement of intracortical electrodes related to their rostral shift due to TBI-induced cortical and hippocampal atrophy and caudal retraction of the brain, and was more severe ipsilaterally than contralaterally (p < 0.001). Total lesion area in cortical subfields targeted by the electrodes (primary somatosensory cortex, visual cortex) was similar between cohorts (p > 0.05). MRI-guided adjustment of coordinates for electrodes improved the success rate of intracortical electrode tip placement nearly to that at the acute postinjury phase (68% vs. 62%), particularly in the posterior brain, which exhibited the most severe postinjury atrophy. Overall, MRI-guided electrode implantation improved the quality and interpretation of the origin of EEG-recorded signals.
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Ali A, Alali Meshari. "Role of T2 Textural Analysis of Prostate Lesion: A Retrospective Study." Pakistan Journal of Medical and Health Sciences 16, no. 3 (March 31, 2022): 1086–89. http://dx.doi.org/10.53350/pjmhs221631086.
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Introduction: Prostate cancer is diagnosed in two-thirds of instances in the world's more developed regions. Prostate cancer was detected in 180,890 new cases in the United States in 2016, according to the American Cancer Society. One out of every six men is projected to develop prostate cancer at some point in their lives. The study's major purpose was to develop a textural analysis-based classifier to differentiate between benign and malignant prostate tumors using MRI-T2WI. Materials and method: The retrospective study was conducted in the department of radiology in KKUH. Total 93 lesions from prostate cases were performed in KKUH from 2015 to 2017. About 75 lesions of 48 patients were included in this study. Eleven haralick features from region of intrests (ROIs) were extracted. After matching them with traces done by consultants in Profuse software, which was utilized for image-guided biopsy, digital rectal examination (DRE), prior biopsy (Prior bx) lesions were traced using ImageJ (MRI-ultrasound fusion). Weka software used this to create a classifier that distinguishes between malignant and benign tumors. Result: The age of total 48 patients was in the interquartile range of 59.0-70.0, with an average of 64.4 years. The PSA was observed an average of 22.5 with an SD of 50.5 and an interquartile of 10.0. The mean size of the prostrate was 3.2 cm with SD 1.9. Among 48 patients Digital rectal examination (DRE) 8 (16.7%) and 40 (83.3%), Prior biopsy (PRIOR BX) 2 (4.2%) and 46 (95.8%), PI-RADS 22 (45.8%) and 26 (54.2%) were observed positive and negative respectively. In DRE, 88% sensitivity 55% specificity with PSA 9.75 (p-value 0.008) were observed. 100% of sensitivity, 41% specificity with PSA 8.19 (p-value 0.897) were found in PRIOR BX, but in MRI, 55% of sensitivity 69% specificity with PSA 10.70 (p-value 0.107) were observed. Conclusion: T2 texture analysis is good in classifying prostate lesions with acceptable sensitivity and specificity. T2W MRI-based textural analysis agreed with pathological findings from many institutions and was sensitive to underlying pathological differences between low- and intermediate/high-grade prostate cancers. Actors in the diagnostic performance, such as DWI/ADC and perfusion, histogram parameters, and other features with distinct orientations and lengths, could help doctors discriminate benign and malignant prostate nodules, allowing for more efficient and precise clinical decisions. Keywords: Prostrate lesion, MRI, textural analysis, cancer
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Verburg, Niels, Thomas Koopman, Maqsood M. Yaqub, Otto S. Hoekstra, Adriaan A. Lammertsma, Frederik Barkhof, Petra J. W. Pouwels, et al. "Improved detection of diffuse glioma infiltration with imaging combinations: a diagnostic accuracy study." Neuro-Oncology 22, no. 3 (September 24, 2019): 412–22. http://dx.doi.org/10.1093/neuonc/noz180.
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Abstract Background Surgical resection and irradiation of diffuse glioma are guided by standard MRI: T2/fluid attenuated inversion recovery (FLAIR)–weighted MRI for non-enhancing and T1-weighted gadolinium-enhanced (T1G) MRI for enhancing gliomas. Amino acid PET has been suggested as the new standard. Imaging combinations may improve standard MRI and amino acid PET. The aim of the study was to determine the accuracy of imaging combinations to detect glioma infiltration. Methods We included 20 consecutive adults with newly diagnosed non-enhancing glioma (7 diffuse astrocytomas, isocitrate dehydrogenase [IDH] mutant; 1 oligodendroglioma, IDH mutant and 1p/19q codeleted; 1 glioblastoma IDH wildtype) or enhancing glioma (glioblastoma, 9 IDH wildtype and 2 IDH mutant). Standardized preoperative imaging (T1-, T2-, FLAIR-weighted, and T1G MRI, perfusion and diffusion MRI, MR spectroscopy and O-(2-[18F]-fluoroethyl)-L-tyrosine ([18F]FET) PET) was co-localized with multiregion stereotactic biopsies preceding resection. Tumor presence in the biopsies was assessed by 2 neuropathologists. Diagnostic accuracy was determined using receiver operating characteristic analysis. Results A total of 174 biopsies were obtained (63 from 9 non-enhancing and 111 from 11 enhancing gliomas), of which 129 contained tumor (50 from non-enhancing and 79 from enhancing gliomas). In enhancing gliomas, the combination of apparent diffusion coefficient (ADC) with [18F]FET PET (area under the curve [AUC], 95% CI: 0.89, 0.79‒0.99) detected tumor better than T1G MRI (0.56, 0.39‒0.72; P < 0.001) and [18F]FET PET (0.76, 0.66‒0.86; P = 0.001). In non-enhancing gliomas, no imaging combination detected tumor significantly better than standard MRI. FLAIR-weighted MRI had an AUC of 0.81 (0.65–0.98) compared with 0.69 (0.56–0.81; P = 0.019) for [18F]FET PET. Conclusion Combining ADC and [18F]FET PET detects glioma infiltration better than standard MRI and [18F]FET PET in enhancing gliomas, potentially enabling better guidance of local therapy.
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Kovtun, Konstantin, Tobias Penzkofer, Neha Agrawal, Tina Kapur, Andriy Fedorov, Robert A. Cormack, Anthony Victor D'Amico, Clare M. Tempany, and Paul Linh Nguyen. "Location of local recurrence after MRI-guided partial prostate brachytherapy targeting only the peripheral zone: Implications for focal therapy." Journal of Clinical Oncology 31, no. 6_suppl (February 20, 2013): 149. http://dx.doi.org/10.1200/jco.2013.31.6_suppl.149.
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149 Background: Prostate cancer local recurrences usually occur at the same site as the dominant primary tumor in patients treated with radiation therapy to the whole gland. We characterized location of local recurrences in patients who were treated with MRI Guided Partial Brachytherapy in which only the peripheral zone was targeted. Methods: We retrospectively reviewed ten patients with initial cT1c, Gleason score 3+4 or less prostate cancer who developed biopsy proven local recurrences and had available imaging after MRI Guided Partial Brachytherapy targeting the peripheral zone from 1998 to 2006. All 10 patients had 1.5T endorectal coil MRI at diagnosis, performed primarily for staging and not for tumor localization, while at recurrence 8 had 3T endorectal coil MRI and 2 had 1.5T endorectal coil MRI. Scans consisted of at least T1 and T2 sequences. Two radiologists (C.T. and T.P.) blinded to clinical data reviewed diagnosis MRI scans together and quantified likelihood of tumor on a 1 to 5 scale in each section of an eight part prostate in both pre-treatment and recurrence scans. Local recurrence was judged to be in the same location as the baseline tumor if at least 50% of the tumor location overlapped. Results: Only 3 of 10 patients had local recurrences at the same location as the baseline tumor with a mean overlap of 64%. 7 of 10 patients had local recurrences at a different location with a mean overlap of 5%. 5 of 10 patients had recurrences in the central zone of the prostate which did not definitively show tumor on review of the initial 1.5T staging scan. Conclusions: After MRI-guided brachytherapy targeting only the peripheral zone in men initially staged with 1.5T MRI, 50% of the local recurrences occurred at the non-targeted central zone, raising the possibility that focal therapy directed only at the dominant tumor will result in increased out-of-field recurrences. Whether the superior ability of modern 3T multiparametric MRI to detect and precisely localize occult prostate cancer foci will reduce this risk is the subject of current study.
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Thomsen, J. B., J. A. Sørensen, P. Grupe, J. Karstoft, and A. Krogdahl. "Staging N0 oral cancer: lymphoscintigraphy and conventional imaging." Acta Radiologica 46, no. 5 (August 2005): 492–96. http://dx.doi.org/10.1080/02841850510021373.
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Purpose: To compare sentinel lymph node biopsy, magnetic resonance imaging (MRI), Doppler ultrasonography, and palpation as staging tools in patients with T1/T2 N0 cancer of the oral cavity. Material and Methods: Forty consecutive patients were enrolled (17 F and 23 M, aged 32–90 years), 24 T1 and 16 T2 cN0 squamous cell carcinoma of the oral cavity. Palpation was carried out by two observers prior to inclusion. MRI, gray-scale and Doppler ultrasonography were performed. Lymphoscintigraphies were done after peritumoral injections of 99mTc labelled rheniumsulphide nanocolloid, followed by sentinel lymph node biopsy guided by a gamma probe and Patent Blue. Palpation, Doppler ultrasonography, MRI, and sentinel lymph node biopsy were compared to a combination of histopathology and follow-up. Diagnostic testing was performed using the x2 test. Results: Histopathological examination revealed metastatic spread to the neck in 14 of 40 patients. One patient had bilateral neck disease. Sentinel lymph node biopsy and ultrasonography were performed in 80 neck sides of 40 patients and MRI in 70 neck sides (5 patients were claustrophobic). SN revealed suspicious lymph nodes in 12 necks, ultrasonography in 23 necks, and MRI in 9 necks. The positive predictive value of sentinel lymph node biopsy was 100%, ultrasonography 57%, and MRI 56%. The respective negative predictive values were 96%, 96%, and 85%. The sensitivity of sentinel lymph node biopsy 80% was comparable to ultrasonography 87%, but the sensitivity of MRI 36% was low. The specificities were 100%, 85%, and 93%, respectively. By combined sentinel lymph node biopsy and ultrasonography the overall sensitivity could have been 100%. Conclusion: Sentinel lymph node biopsy improved staging of patients with small N0 oral cancers. Combined sentinel lymph node biopsy and Doppler ultrasonography may further improve staging. MRI and simple palpation results were poor.
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Liney, Gary P., Jenny E. Marsden, Carl J. Horsfield, Tom Murray, David J. Manton, and Andrew W. Beavis. "Improved visualisation of cervix applicators for magnetic resonance-only-guided brachytherapy planning." Journal of Radiotherapy in Practice 13, no. 2 (January 22, 2014): 159–65. http://dx.doi.org/10.1017/s1460396913000514.
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AbstractObjectivesCurrent guidelines for image-guided cervical cancer brachytherapy planning recommend both computed tomography (CT) and magnetic resonance imaging (MRI) for adequate visualisation of the applicator and soft tissues, respectively. MRI-only planning would be ideal as it would save time within the patient pathway and avoid the concomitant CT exposures. However, applicator visualisation on MRI is usually achieved using fluid-filled fiducial marker tubes, which can be awkward to use and suffer from unwanted air bubble artefacts. Therefore, a new fiducial-free imaging technique was developed.MethodsA dual echo time (TE) turbo spin echo sequence was used, at 1·5 T, to provide both T2-weighted images (100 ms TE) for tissue visualisation and strongly proton density-weighted images (17 ms TE) for improved applicator visualisation. In-house software was used to automatically segment the applicator in the short TE images (using Otsu's method) and transfer the information to the long TE images to provide a single fused dataset.ResultsThe method was evaluated successfully using titanium applicators in three patient cases and using a plastic applicator in a tissue-equivalent gel phantom.ConclusionsThe dual-echo technique provides a simple and efficient method for improving the visualisation of brachytherapy applicators in cervical cancer MRI images without the need for marker tubes.
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Pirotte, Benoit, Serge Goldman, Patrick Van Bogaert, Philippe David, David Wikler, Sandrine Rorive, Jacques Brotchi, and Marc Levivier. "Integration of [11C]Methionine-Positron Emission Tomographic and Magnetic Resonance Imaging for Image-guided Surgical Resection of Infiltrative Low-grade Brain Tumors in Children." Operative Neurosurgery 57, suppl_1 (July 1, 2005): 128–39. http://dx.doi.org/10.1227/01.neu.0000163598.59870.6d.
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Abstract OBJECTIVE: To evaluate the interest of integrating positron emission tomography (PET) images with the radiolabeled tracer [11C]methionine (Met) into the image-guided navigation planning of infiltrative low-grade brain tumors (LGBTs) in children. METHODS: Twenty-two children underwent combined Met-PET with magnetic resonance imaging (MRI) scans in the planning of a navigation procedure. These children presented an LGBT (astrocytomas, 10; oligodendrogliomas, 4; ependymomas, 4; gangliogliomas, 4) located close to functional areas. Tumor boundaries were ill-defined on MRI (including T2-weighted and fluid-attenuated inversion-recovery scans) and could not be clearly identified for allowing a complete, or at least a large, image-guided resection. The PET tracer Met was chosen because of its higher sensitivity and specificity than MRI to detect tumor tissue. The level and extension of MET uptake were analyzed to define the PET contour, subsequently projected onto MRI scans to define a final target contour for volumetric resection. The quality of tumor resection was assessed by an early postoperative MRI and Met-PET workup. RESULTS: In 20 of the 22 children with ill-defined LGBTs, PET improved tumor delineation and contributed to define a final target contour different from that obtained with MRI alone. Met-PET guidance allowed a total resection of Met uptake in 17 cases that were considered total tumor resections because the operative margin left in place contained nontumor tissue. CONCLUSION: These data suggested that Met-PET guidance could help to improve the number of total resections and the amount of tumor removed in infiltrative LGBTs in children.
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Harvey, Hugh, and Nandita M. deSouza. "The role of imaging in the diagnosis of primary prostate cancer." Journal of Clinical Urology 9, no. 2_suppl (December 2016): 11–17. http://dx.doi.org/10.1177/2051415816656120.
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Ultrasound and magnetic resonance imaging (MRI) are key imaging modalities in prostate cancer diagnosis. MRI offers a range of intrinsic contrast mechanisms (T2, diffusion-weighted imaging (DWI), MR spectroscopy (MRS)) and extrinsic contrast-generating options based on tumour vascular state following injection of weakly paramagnetic agents such as gadolinium. Together these parameters are referred to as multiparametric (mp)MRI and are used for detecting and guiding biopsy and staging prostate cancer. Although sensitivity of mpMRI is <75% for disease detection, specificity is >90% and a standardised reporting system together with MR-guided targeted biopsy is the optimal diagnostic pathway. Shear wave ultrasound elastography is a new technique which also holds promise for future studies. This article describes the developments in imaging the primary site of prostate cancer and reviews their current and future utility for screening, diagnosis and T-staging the disease.
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Ahmad, Mohammad Yaseen, Huan Yue, Tirusew Tegafaw, Shuwen Liu, Son Long Ho, Gang Ho Lee, Sung-Wook Nam, and Yongmin Chang. "Functionalized Lanthanide Oxide Nanoparticles for Tumor Targeting, Medical Imaging, and Therapy." Pharmaceutics 13, no. 11 (November 8, 2021): 1890. http://dx.doi.org/10.3390/pharmaceutics13111890.
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Recent progress in functionalized lanthanide oxide (Ln2O3) nanoparticles for tumor targeting, medical imaging, and therapy is reviewed. Among the medical imaging techniques, magnetic resonance imaging (MRI) is an important noninvasive imaging tool for tumor diagnosis due to its high spatial resolution and excellent imaging contrast, especially when contrast agents are used. However, commercially available low-molecular-weight MRI contrast agents exhibit several shortcomings, such as nonspecificity for the tissue of interest and rapid excretion in vivo. Recently, nanoparticle-based MRI contrast agents have become a hot research topic in biomedical imaging due to their high performance, easy surface functionalization, and low toxicity. Among them, functionalized Ln2O3 nanoparticles are applicable as MRI contrast agents for tumor-targeting and nontumor-targeting imaging and image-guided tumor therapy. Primarily, Gd2O3 nanoparticles have been intensively investigated as tumor-targeting T1 MRI contrast agents. T2 MRI is also possible due to the appreciable paramagnetic moments of Ln2O3 nanoparticles (Ln = Dy, Ho, and Tb) at room temperature arising from the nonzero orbital motion of 4f electrons. In addition, Ln2O3 nanoparticles are eligible as X-ray computed tomography contrast agents because of their high X-ray attenuation power. Since nanoparticle toxicity is of great concern, recent toxicity studies on Ln2O3 nanoparticles are also discussed.
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Peters, Inga, Katja Derlin, Matti Joonas Peperhove, Bennet Hensen, Stefanie Pertschy, Mathias Wolters, Christoph-Alexander Joachim von Klot, Frank Wacker, and Susanne Hellms. "First experiences and results after cryoablation of prostate cancer with histopathological evaluation and imaging-based follow-up." Future Oncology 18, no. 14 (May 2022): 1705–16. http://dx.doi.org/10.2217/fon-2021-1146.
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Aim: To share our experience after 28 cryoablation treatments for prostate cancer (PCa) with histopathology, clinical data and MRI as the follow-up methods. Methods: Clinical follow-up comprised prostate-specific antigen (PSA)-measurements, PSA-density and quality of life-parameters. multi-parametric (mp)MRI pre- and post-cryoablation were retrospectively re-analyzed in 23 cases using Likert scores. Follow-up-histopathology was performed via MRI/ultrasound fusion-guided and/or systematic biopsy. Receiver operating characteristic curve analysis was performed. Results: 17 PCa (61%) were diagnosed within 12-month post-cryotherapy (infield and out-of-field disease). PSA levels and PSA density were not significantly different between patients with or without PCa recurrence. mpMRI can characterize the decrease in prostate volume and necrosis. Area under the curve for the detection of PCa was 81% (global Likert scores), 74–87% (T2), 78% (diffusion weighted imaging) and 57–78% (dynamic contrast enhanced imaging; Youden-selected cutoff ≥3). Conclusion: Besides histopathological evaluation and control biopsy, MRI might have the potential to accurately detect PCa after cryotherapy. Clinical data and interdisciplinary communication are required for efficient monitoring after cryoablation treatments for PCa.
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Poudel, Hari, Rajeev Bhandari, Bikesh Kumar Khambu, Rajendra Shrestha, Rajeev Jha, and Prakash Bista. "Schwannoma Presenting As Pituitary Macroadenoma: Case Report." Nepal Journal of Neuroscience 16, no. 2 (October 17, 2019): 59–62. http://dx.doi.org/10.3126/njn.v16i2.25958.
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Schwannoma is common intracranial tumor. They are benign tumor arising from Cranial nerves or peripheral nerves. Majority of these tumors occur at Cerebellopontine angle. 54-year right handed lady presented with history of progressive loss of vision on both eyes for last five years. It started on her left eye initially pronounced on lateral field which gradually progressed to involve right eye. MRI of brain showed a well-defined mass of size 39*35*29mm in sellar region extending to suprasellar region with T1 is intensity and T2 hyperintensity. Endonasal trans-sphenoidal resection of lesion was done guided by navigation. Surprisingly histopathology turned out to be Schwannoma.
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Tony, Surekha, Shahina Daar, Shoaib Al Zadjali, Murtadha K. Al-Khabori, Mohammed El Shinawy, and Yasser Wali. "T2* MRI in Hypertransfused Children with Thalassemia Intermedia: Serum Ferritin Does Not Reflect the Reality." Blood 118, no. 21 (November 18, 2011): 5304. http://dx.doi.org/10.1182/blood.v118.21.5304.5304.
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Abstract Abstract 5304 Background: Non-transfused patients with thalassemia intermedia (TI) accumulate iron in their body due to increased gastrointestinal absorption of iron and release of iron from the macrophages. Earlier studies have revealed that serum ferritin does not reflect the severity of iron overload in non-transfused TI patients. The current study aims at evaluating the iron overload status in a group of young hypertransfused TI children. Materials and Methods: Eleven patients (mean age 13.18±4.094 years) with TI on regular follow-up at the Pediatric Thalassemia Day Care Centre, Sultan Qaboos University Hospital, Oman were included in the study after approval by the Medical Research and Ethics Committee. All patients had beta gene mutational analysis. They were diagnosed as intermedia because of their definitive TI mutation, late age at presentation (>5 years) and transfusion independence (mean baseline Hb 6.9 g/dl). Patients were treated conventionally with hypertransfusion, and chelation, as guided by their serum ferritin levels. Serum ferritin (2 monthly) was analyzed using the Beckman Coulter Access 2 Immunoassay System. Based on serum ferritin levels, patients were classified into 2 groups, group 1(six patients) and 2 (five patients) with serum ferritin levels below and above 1000 ng/ml respectively. All patients underwent cardiac T2* MRI assessment. Based on local reference values for T2*MRI, quantification of cardiac iron deposition was categorized as normal, mild, moderate and severe iron overload at values > 20 ms, 14–20 ms, 10–14 ms and < 10 ms respectively. Simultaneous liver iron T2* values were categorized into normal, mild, moderate and severe iron overload at values > 9.1 ms, 7.1–9.0 ms, 3.1– 7.0 ms and <3.0 ms respectively. Results: Patients in group 1 and 2 had mean serum ferritin levels of 817.300±244.690 ng/ml and 1983.80±662.862 ng/ml respectively (p = 0.003). Despite this very high variation in serum ferritin values, T2* MRI showed comparable hepatic iron overload status in both the groups with mean hepatic T2* value of 2.51±0.46 ms and 3.4±1.63 ms in group 1 and group 2 respectively. The difference in hepatic T2* between the 2 groups is −0.88 (95% confidence interval −2.44 to 0.68) which is statistically insignificant (p =0.23, t-test). None of the studied patients had myocardial iron deposition (overall mean 36.86±7.8 ms). Other confounders like initial ages at presentation, pre-transfusion hemoglobin levels, durations of transfusion and chelation therapies were statistically insignificant for the 2 groups. No specific pattern of beta gene sequence was noted in either group. Conclusions: We conclude in our patients with TI on hypertransfusion, serum ferritin does not reflect their moderate to severe hepatic iron overload status. Inspite of steady serum ferritin trends, evaluation of iron overload by T2* MRI and optimal chelation is strongly recommended in hypertransfused TI patients. Disclosures: No relevant conflicts of interest to declare.
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Sequeiros, Roberto Blanco, Juho Kariniemi, Risto Ojala, Li Chengli, Marianne Haapea, Andreas Blanco Sequeiros, and Osmo Tervonen. "Liver tumor laser ablation – increase in the subacute ablation lesion volume detected with post procedural MRI." Acta Radiologica 51, no. 5 (June 2010): 505–11. http://dx.doi.org/10.3109/02841851003694783.
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Background: The use of image-guided thermoablative methods in liver tumor treatment has expanded rapidly due to encouraging results and advanced imaging. However, little is known about the treatment-induced tissue response and effects on imaging findings during the subacute post procedural period. Purpose: To study the development of subacute ablation zone volume with magnetic resonance imaging (MRI) after laser-mediated liver tumor thermal therapy. Material and Methods: In all, 16 laser ablations were performed on 16 liver tumors resulting in 16 ablation zones in 11 consecutive patients. A low-field 0.23 T C-arm MRI scanner was used for imaging and procedural guidance. Repeated dynamic contrast-enhanced T1, contrast-enhanced T1 FSE, and T2 FSE studies of liver were performed at 0 and 72 h after the procedure. Ablation zone volumes were registered from the acquired image data. Results: MRI scans showed a significant increase of ablation volume in all imaging sequences obtained at 72 h after the initial therapy. Conclusion: After laser ablation, there is a progressive perfusion decrease in the ablation site leading to an increase in the ablation volume. Post procedural baseline MRI at 72 h from the treatment provides more precise information about the ablation result than can be obtained with immediate post procedural MRI.
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Winkel, David J., Christian Wetterauer, Marc Oliver Matthias, Bin Lou, Bibo Shi, Ali Kamen, Dorin Comaniciu, Hans-Helge Seifert, Cyrill A. Rentsch, and Daniel T. Boll. "Autonomous Detection and Classification of PI-RADS Lesions in an MRI Screening Population Incorporating Multicenter-Labeled Deep Learning and Biparametric Imaging: Proof of Concept." Diagnostics 10, no. 11 (November 14, 2020): 951. http://dx.doi.org/10.3390/diagnostics10110951.
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Background: Opportunistic prostate cancer (PCa) screening is a controversial topic. Magnetic resonance imaging (MRI) has proven to detect prostate cancer with a high sensitivity and specificity, leading to the idea to perform an image-guided prostate cancer (PCa) screening; Methods: We evaluated a prospectively enrolled cohort of 49 healthy men participating in a dedicated image-guided PCa screening trial employing a biparametric MRI (bpMRI) protocol consisting of T2-weighted (T2w) and diffusion weighted imaging (DWI) sequences. Datasets were analyzed both by human readers and by a fully automated artificial intelligence (AI) software using deep learning (DL). Agreement between the algorithm and the reports—serving as the ground truth—was compared on a per-case and per-lesion level using metrics of diagnostic accuracy and k statistics; Results: The DL method yielded an 87% sensitivity (33/38) and 50% specificity (5/10) with a k of 0.42. 12/28 (43%) Prostate Imaging Reporting and Data System (PI-RADS) 3, 16/22 (73%) PI-RADS 4, and 5/5 (100%) PI-RADS 5 lesions were detected compared to the ground truth. Targeted biopsy revealed PCa in six participants, all correctly diagnosed by both the human readers and AI. Conclusions: The results of our study show that in our AI-assisted, image-guided prostate cancer screening the software solution was able to identify highly suspicious lesions and has the potential to effectively guide the targeted-biopsy workflow.
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Ohno, Tatsuya, Masaru Wakatsuki, Takafumi Toita, Yuko Kaneyasu, Ken Yoshida, Shingo Kato, Noriko Ii, et al. "Recommendations for high-risk clinical target volume definition with computed tomography for three-dimensional image-guided brachytherapy in cervical cancer patients." Journal of Radiation Research 58, no. 3 (November 10, 2016): 341–50. http://dx.doi.org/10.1093/jrr/rrw109.
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Abstract Our purpose was to develop recommendations for contouring the computed tomography (CT)-based high-risk clinical target volume (CTVHR) for 3D image-guided brachytherapy (3D-IGBT) for cervical cancer. A 15-member Japanese Radiation Oncology Study Group (JROSG) committee with expertise in gynecological radiation oncology initiated guideline development for CT-based CTVHR (based on a comprehensive literature review as well as clinical experience) in July 2014. Extensive discussions occurred during four face-to-face meetings and frequent email communication until a consensus was reached. The CT-based CTVHR boundaries were defined by each anatomical plane (cranial–caudal, lateral, or anterior–posterior) with or without tumor progression beyond the uterine cervix at diagnosis. Since the availability of magnetic resonance imaging (MRI) with applicator insertion for 3D planning is currently limited, T2-weighted MRI obtained at diagnosis and just before brachytherapy without applicator insertion was used as a reference for accurately estimating the tumor size and topography. Furthermore, utilizing information from clinical examinations performed both at diagnosis and brachytherapy is strongly recommended. In conclusion, these recommendations will serve as a brachytherapy protocol to be used at institutions with limited availability of MRI for 3D treatment planning.