Journal articles: 'T1-weighted magnetic resonance imaging'

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Forgues, M., R. Mehta, D. Anderson, C. Morel, L. Miller, A. Sevy, L. Son, and M. Arriaga. "Non-contrast magnetic resonance imaging for monitoring patients with acoustic neuroma." Journal of Laryngology & Otology 132, no. 9 (August 17, 2018): 780–85. http://dx.doi.org/10.1017/s0022215118001342.

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AbstractObjectiveTo assess the feasibility of non-contrast T2-weighted magnetic resonance imaging as compared to T1-weighted post-contrast magnetic resonance imaging for detecting acoustic neuroma growth.MethodsAdult patients with acoustic neuroma who underwent at least three magnetic resonance imaging scans of the internal auditory canals with and without contrast in the past nine years were identified. T1- and T2-weighted images were reviewed by three neuroradiologists, and tumour size was measured. Accuracy of the measurements on T2-weighted images was defined as a difference of less than or equal to 2 mm from the measurement on T1-weighted images.ResultsA total of 107 magnetic resonance imaging scans of 26 patients were reviewed. Measurements on T2-weighted magnetic resonance imaging scans were 88 per cent accurate. Measurements on T2-weighted images differed from measurements on T1-weighted images by an average of 1.27 mm, or 10.4 per cent of the total size. The specificity of T2-weighted images was 88.2 per cent and the sensitivity was 77.8 per cent.ConclusionThe T2-weighted sequences are fairly accurate in measuring acoustic neuroma size and identifying growth if one keeps in mind the caveats associated with the tumour characteristics or location.

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Bhalodiya, Jayendra M., Sarah N. Lim Choi Keung, and Theodoros N. Arvanitis. "Magnetic resonance image-based brain tumour segmentation methods: A systematic review." DIGITAL HEALTH 8 (January 2022): 205520762210741. http://dx.doi.org/10.1177/20552076221074122.

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Background Image segmentation is an essential step in the analysis and subsequent characterisation of brain tumours through magnetic resonance imaging. In the literature, segmentation methods are empowered by open-access magnetic resonance imaging datasets, such as the brain tumour segmentation dataset. Moreover, with the increased use of artificial intelligence methods in medical imaging, access to larger data repositories has become vital in method development. Purpose To determine what automated brain tumour segmentation techniques can medical imaging specialists and clinicians use to identify tumour components, compared to manual segmentation. Methods We conducted a systematic review of 572 brain tumour segmentation studies during 2015–2020. We reviewed segmentation techniques using T1-weighted, T2-weighted, gadolinium-enhanced T1-weighted, fluid-attenuated inversion recovery, diffusion-weighted and perfusion-weighted magnetic resonance imaging sequences. Moreover, we assessed physics or mathematics-based methods, deep learning methods, and software-based or semi-automatic methods, as applied to magnetic resonance imaging techniques. Particularly, we synthesised each method as per the utilised magnetic resonance imaging sequences, study population, technical approach (such as deep learning) and performance score measures (such as Dice score). Statistical tests We compared median Dice score in segmenting the whole tumour, tumour core and enhanced tumour. Results We found that T1-weighted, gadolinium-enhanced T1-weighted, T2-weighted and fluid-attenuated inversion recovery magnetic resonance imaging are used the most in various segmentation algorithms. However, there is limited use of perfusion-weighted and diffusion-weighted magnetic resonance imaging. Moreover, we found that the U-Net deep learning technology is cited the most, and has high accuracy (Dice score 0.9) for magnetic resonance imaging-based brain tumour segmentation. Conclusion U-Net is a promising deep learning technology for magnetic resonance imaging-based brain tumour segmentation. The community should be encouraged to contribute open-access datasets so training, testing and validation of deep learning algorithms can be improved, particularly for diffusion- and perfusion-weighted magnetic resonance imaging, where there are limited datasets available.

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Zhalniarovich, Y., A. Przeworski, J. Glodek, and Z. Adamiak. "Low-field magnetic resonance imaging of otitis media in two cats: a case report." Veterinární Medicína 62, No. 2 (February 13, 2017): 111–15. http://dx.doi.org/10.17221/94/2016-vetmed.

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Otitis media is a common disease in clinical veterinary practice. Although low-field magnetic resonance imaging reports for otitis media in dogs exist, in cats detailed information is missing. Radiography is helpful in diagnosing chronic inflammation, but may be insufficient during the initial phase of inflammation. For this reason, this report describes the magnetic resonance findings in two cats with otitis media. In both cases, middle ear empyema was detected. Magnetic resonance imaging of middle ear disorders in cats should contain pre- and post-contrast T1-weighted sequences in the dorsal and transverse planes, a T2-weighted sequence in the dorsal and transverse planes and a fluid-attenuated inversion recovery sequence in the dorsal or transverse planes. On pre-contrast T1-weighted images, the empyema had an intensity similar to that of brain tissue with a delicate hyper-intensity in the middle. On post-contrast T1-weighted images, the material had non-uniform enhancement in the dorsolateral compartment and circumference enhancement in the ventromedial compartment of the tympanic bulla with a hypo-intense centre. On T2-weighted images, the mass had heterogeneously increased signal intensity to brain tissue, but was less intense than cerebrospinal fluid. In the fluid-attenuated inversion recovery sequence, the pathological lesion was distinctly hyper-intense in comparison to other tissues with a narrow area of increased signal intensity in the middle of the ventromedial tympanic bulla compartment. Magnetic resonance imaging is commonly used for the visualisation of different disorders of the membranous labyrinth and allows the differentiation of chronic hematomas, empyemas and middle and internal ear neoplasia. The recommended magnetic resonance protocol of the middle ear should include pre- and post-contrast T1 sequences in the dorsal and transverse planes, the T2 sequence in the dorsal and transverse planes and the fluid-attenuated inversion recovery sequence in the dorsal or transverse planes.

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IMAEDA, T., R. NAKAMURA, T. MIURA, and N. MAKINO. "Magnetic Resonance Imaging in Scaphoid Fractures." Journal of Hand Surgery 17, no. 1 (February 1992): 20–27. http://dx.doi.org/10.1016/0266-7681(92)90007-o.

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The use of a 1.5 tesla superconducting M.R. imager and surface coil was found to enhance the ability of M.R.I, to depict the fine anatomy of the wrist. Five healthy volunteers and 28 patients with scaphoid fractures underwent M.R.I., which made possible a definitive diagnosis of scaphoid fractures at an early stage. A fresh fracture was identified by decreased or iso signal intensity on the T1-weighted image and increased signal intensity on the T2-weighted image. This increase continued until bony union was apparent on radiographs. On the T2-weighted image, high signal intensity was characteristic of fresh fractures and suggested that bony union was possible. When bony union was complete, the intensity of the signal for the scaphoid on both T1 and T2-weighted images returned to normal. M.R.I. should thus prove useful in the diagnosis of scaphoid fractures.

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Glodek, J., Z. Adamiak, M. Mieszkowska, and A. Przeworski. "Low-field magnetic resonance imaging of changes after femoral osteosynthesis failure: a case report." Veterinární Medicína 62, No. 11 (November 16, 2017): 625–30. http://dx.doi.org/10.17221/145/2016-vetmed.

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We describe here a case study of a 16-month-old female European shorthair cat examined about 6 months after the osteosynthesis of a femoral fracture. Clinical examination revealed a non-weightbearing left limb, pain upon manipulation of the hip joint, complete immobilisation of the stifle joint and muscle atrophy in the left thigh. Low-field magnetic resonance images were acquired in sagittal, transverse and dorsal planes with T1-weighted spin echo, T2-weighted fast spin echo, T1-weighted gradient echo, gradient echo short tau inversion recovery and T1-weighted XBone sequences. Total examination time was 59 min 20 s. The obtained images revealed the presence of osteophytes on the surface of the femoral head, subluxation of the hip joint, atrophy and fatty infiltration of the quadriceps femoris muscle. The symmetry and size of callus in the fracture site were also evaluated. Based on the results of the magnetic resonance imaging exam, the patient was diagnosed with hip osteoarthritis, atrophy and fatty degeneration of the quadriceps femoris muscle with homogeneous and symmetrical distribution of callus in the fracture site. The results of this study confirm the high diagnostic value of low-field magnetic resonance imaging in diagnostics of musculoskeletal injuries in cats.

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IMAEDA, T., R. NAKAMURA, T. MIURA, and N. MAKINO. "Magnetic Resonance Imaging in Kienböck’s Disease." Journal of Hand Surgery 17, no. 1 (February 1992): 12–19. http://dx.doi.org/10.1016/0266-7681(92)90006-n.

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With a 1.5 tesla superconducting M.R. imager and surface coil, M.R. imaging achieved high resolution analysis of the wrist on five normal wrists and 26 wrists with Kienböck’s disease. The purpose of this study was to establish new criteria for diagnosis, staging and prognosis of Kienböck’s disease, based on signal characteristics on T1-and T2-weighted images. Focal loss of signal intensity of the lunate on T1-weighted image was an indication of Kienböck’s disease. A decreased signal containing a high spot and increased signal intensity of the lunate on T2-weighted images indicated a better prognosis. After osteotomy of the radius, the signal intensity of the lunate returned to normal and Lichtman’s stage II cases had better results than those in stage III. M.R. imaging is ideal for evaluating the lunate in Kienböck’s disease.

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Sutherland, Garnette R., Taro Kaibara, Carla Wallace, Boguslaw Tomanek, and Marlene Richter. "Intraoperative Assessment of Aneurysm Clipping Using Magnetic Resonance Angiography and Diffusion-weighted Imaging: Technical Case Report." Neurosurgery 50, no. 4 (April 1, 2002): 893–98. http://dx.doi.org/10.1097/00006123-200204000-00044.

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Abstract OBJECTIVE AND IMPORTANCE: To use intraoperative magnetic resonance imaging, including magnetic resonance angiography and diffusion-weighted imaging, to monitor the surgical treatment of a patient with an intracranial aneurysm. TECHNIQUE: Intraoperative imaging was performed with a ceiling-mounted, mobile, 1.5-T magnet (developed in collaboration with Innovative Magnetic Resonance Imaging Systems, Inc., Winnipeg, MB, Canada) that included high-performance 20-mT/m gradients. Pre- and postclipping, intraoperative, T1-weighted, angiographic and diffusion-weighted magnetic resonance images were obtained from a patient with an incidental, 8-mm, anterior communicating artery aneurysm. RESULTS: T1-weighted images demonstrated brain anatomic features, with visible shifts induced by surgery. Magnetic resonance angiography demonstrated the aneurysm and indicated that, after clipping, the A1 and A2 anterior cerebral artery branches were patent. Diffusion-weighted studies demonstrated no evidence of brain ischemia. CONCLUSION: For the first time, intraoperative magnetic resonance imaging has been used to monitor the surgical treatment of a patient with an intracranial aneurysm.

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Batta, Akash, Karthik Vinay Mahesh, Nandita Prabhat, Ritu Shree, Manoj K. Goyal, Chirag K. Ahuja, Alex Rebello, et al. "Newer magnetic resonance imaging techniques in neurocysticercosis." Neuroradiology Journal 33, no. 6 (August 26, 2020): 538–44. http://dx.doi.org/10.1177/1971400920949394.

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Introduction The definitive diagnosis of neurocysticercosis continues to be challenging. We evaluate the role of newer magnetic resonance imaging techniques including constructive interference in steady state, susceptibility-weighted imaging, arterial spin labelling and magnetic resonance spectroscopy in the diagnosis of neurocysticercosis. Aims and objectives To study the utility of newer magnetic resonance imaging sequences in the diagnosis of neurocysticercosis. Patients and methods Eighty-five consecutive patients with neurocysticercosis attending a tertiary care hospital and teaching centre in northern India were included in the study. The diagnosis of neurocysticercosis was made by the Del Brutto criteria. All patients received treatment according to standard guidelines and were followed at 3-month intervals. The following magnetic resonance sequences were performed at baseline: T1 and T2-weighted axial sequences; T2 fluid-attenuated inversion recovery axial sequences; diffusion-weighted imaging; susceptibility-weighted imaging; pre and post-contrast T1-weighted imaging; heavily T2-weighted thin sections (constructive interference in steady state); arterial spin labelling ( n = 19); and magnetic resonance spectroscopy ( n = 24). Results The mean (±SD) age was 29.4 ± 12.9 years and 76.5% were men. Seizures were the commonest symptom (89.4%) followed by headache (24.3%), encephalitis (9.4%) and raised intracranial pressure (9.4%). Scolex could be visualised in 43.7%, 55.5% and 61.2% of neurocysticercosis patients using conventional, susceptibility-weighted angiography and constructive interference in steady state imaging sequences, respectively. Susceptibility-weighted angiography and constructive interference in steady state images resulted in significantly higher ( P < 0.01) visualisation of scolex compared to conventional sequences. Conclusion Newer magnetic resonance imaging modalities have a lot of promise for improving the radiological diagnosis of neurocysticercosis.

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Kassamali, R. H., and S. J. Karia. "Axial T1 weighted magnetic resonance imaging of the sacrum." BMJ 348, jan07 10 (January 7, 2014): f7712. http://dx.doi.org/10.1136/bmj.f7712.

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Shen, Wei, Xiuqun Gong, Jessica Weiss, and Ye Jin. "Comparison among T1-Weighted Magnetic Resonance Imaging, Modified Dixon Method, and Magnetic Resonance Spectroscopy in Measuring Bone Marrow Fat." Journal of Obesity 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/298675.

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Introduction. An increasing number of studies are utilizing different magnetic resonance (MR) methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI), modified Dixon method (also called fat fraction MRI (FFMRI)), and magnetic resonance spectroscopy (MRS).Methods. Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI). Bone marrow adipose tissue (BMAT) of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra.Results. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 in femoral necks.Conclusion. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

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Hisa, Yasuo, Keigo Tatemoto, Kenji Dejima, Yasuyuki Nishiyama, Yukari Masuda, and Haruyasu Ikuta. "Magnetic resonance imaging for aspirated peanut in the bronchus." Journal of Laryngology & Otology 108, no. 9 (September 1994): 804–5. http://dx.doi.org/10.1017/s002221510012818x.

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AbstractPeanut inhalation in the right main bronchus of a 15-month-old boy was diagnosed using a T1-weighted image produced by magnetic reasonance imaging (MRI) because of the high fat content of the peanut. The T1-weighted MRI image may also be useful in diagnosing other kinds of aspirated nuts with high lipid content as well as peanuts. This method does not involve any X-ray exposure.

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Matsuura, Koichiro, Kaiji Inoue, Eri Hoshino, Masanori Yasuda, Kosei Hasegawa, Yoshitaka Okada, Yasutaka Baba, and Eito Kozawa. "Utility of magnetic resonance imaging for differentiating malignant mesenchymal tumors of the uterus from T2-weighted hyperintense leiomyomas." Japanese Journal of Radiology 40, no. 4 (November 9, 2021): 385–95. http://dx.doi.org/10.1007/s11604-021-01217-2.

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Abstract Purpose To generate a new discrimination method to distinguish between malignant mesenchymal tumors of the uterus and T2-weighted hyperintense leiomyoma based on magnetic resonance imaging findings and clinical features. Materials and methods Data from 32 tumors of 32 patients with malignant mesenchymal tumors of the uterus and from 34 tumors of 30 patients with T2-weighted hyperintense leiomyoma were analyzed. Clinical parameters, qualitative magnetic resonance imaging features, including computed diffusion-weighted imaging, and quantitative characteristics of magnetic resonance imaging of these two tumor types were compared. Predictive values for malignant mesenchymal tumors of the uterus were calculated using variant discriminant analysis. Results The T1 bright area on qualitative assessment and mean apparent diffusion coefficient value on quantitative assessment yielded the most independent magnetic resonance imaging differentiators of malignant mesenchymal tumors of the uterus and T2-weighted hyperintense leiomyoma. The classification accuracy of the variant discriminant analysis based on three selected findings, i.e., a T1 bright area, computed diffusion-weighted imaging with a b-value of 2000s/mm2 (cDWI2000), and T2-hypointense bands, was 84.8% (56/66), indicating high accuracy. Conclusions Variant discriminant analysis using the T1 bright area, cDWI2000, and T2-hypointense bands yielded high accuracy for differentiating between malignant mesenchymal tumors of the uterus and T2-weighted hyperintense leiomyoma.

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Ren, Hong, Wei Lin, and Xianjun Ding. "Surface coil intensity correction in magnetic resonance imaging in spinal metastases." Open Medicine 12, no. 1 (May 20, 2017): 138–43. http://dx.doi.org/10.1515/med-2017-0021.

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AbstractObjectiveTo evaluate the clinical application of phased-array surface coil intensity correction in magnetic resonance imaging (MRI) in spinal metastases.Methods3 phantoms and 50 patients with a corresponding total number of 80 spinal metastases were included in this study. Fast spin echo T1- and T2- weighted MRI with and without surface coil intensity correction was routinely performed for all phantoms and patients. Phantoms were evaluated by means of variance to mean ratio of signal intensity on both T1- and T2- weighted MRI obtained with and without surface coil intensity correction. Spinal metastases were evaluated by image quality scores; reading time per case on both T1- and T2- weighted MRI obtained with and without surface coil intensity correction.ResultsSpinal metastases were diagnosed more successfully on MRI with surface coil intensity correction than on MRI with conventional surface coil technique. The variance to mean ratio of signal intensity was 53.36% for original T1-weighted MRI and 53.58% for original T2-weighted MRI. The variance to mean ratio of signal intensity was reduced to 18.99% for T1-weighted MRI with surface coil intensity correction and 22.77% for T2-weighted MRI with surface coil intensity correction. The overall image quality scores (interface conspicuity of lesion and details of lesion) were significantly higher than those of the original MRI. The reading time per case was shorter for MRI with surface coil intensity correction than for MRI without surface coil intensity correction.ConclusionsPhased-array surface coil intensity correction in MRIs of spinal metastases provides improvements in image quality that leads to more successfully detection and assessment of spinal metastases than original MRI.

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Neal, Chris J., Michael K. Rosner, and Timothy R. Kuklo. "Magnetic resonance imaging evaluation of adjacent segments after disc arthroplasty." Journal of Neurosurgery: Spine 3, no. 5 (November 2005): 342–47. http://dx.doi.org/10.3171/spi.2005.3.5.0342.

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Object. Disc arthroplasty in the lumbar spine is an alternative to fusion when treating discogenic pain. Its theoretical benefits include preservation of the motion segment and the potential prevention of adjacent-segment degeneration. Despite the need to evaluate the benefit of preserving the adjacent segments after disc replacement, no study has been conducted to assess the ability of magnetic resonance (MR) imaging to depict the adjacent segments in patients who have undergone disc replacement surgery. Methods. Postoperative lumbar MR images were obtained in the first 10 patients in whom a metal-on-metal disc arthroplasty system was used to treat the L4–5 or L5—S1 levels. At the superior adjacent level, the superior endplate and disc space were demonstrated on 90% of the images on both T1-weighted fluid-attenuated inversion-recovery (FLAIR) and T2-weighted sequences despite the presence of artifacts. The inferior endplate at this level was documented on 70% of both T1-weighted FLAIR and T2-weighted sequences. At the level below the disc replacement in patients who underwent L4–5 surgery, the superior endplate was demonstrated on 66.7% of the T1-weighted FLAIR sequences but only 33.3% of the T2-weighted images. The disc space and inferior endplate were depicted on 66.7% of both T1-weighted FLAIR and T2-weighted sequences. Axial images revealed an artifact in every adjacent space except at the L5—S1 level. Conclusions. Based on the results of this pilot study, it appears that sagittal MR imaging can be undertaken to evaluate the adjacent motion segment for degenerative changes following total disc arthroplasty in most patients. This imaging modality will provide an additional measure to assess the long-term efficacy of this intervention compared with other treatment modalities and the natural history of lumbar disc degeneration.

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Lu, Yue, Shirui Zhao, and Xin-an Zhang. "Fabrication of Mn2+-Doped Hollow Mesoporous Aluminosilica Nanoparticles for Magnetic Resonance Imaging and Drug Delivery for Therapy of Colorectal Cancer." Journal of Nanomaterials 2019 (November 3, 2019): 1–6. http://dx.doi.org/10.1155/2019/3525143.

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A novel Mn2+-doped hollow Mn-HMAS aluminosilica (Mn-HMAS) nanoparticle for simultaneous T1-weighted magnetic resonance imaging and drug delivery was reported. The magnetic resonance tests showed that the Mn-HMAS nanoparticles display an excellent T1-weighted magnetic resonance imaging effect with a high T1 relaxivity (r1) of 8.8 mM-1S-1. The MTT assays showed that the Mn-HMAS-DOX nanoparticles possess a better tumour cell inhibition effect than DOX. In addition, the Mn-HMAS nanoparticles also exhibit good stability and noncytotoxicity. These results demonstrated that the Mn-HMAS nanoparticles can be applied for the loading and delivery of various drugs in medicine.

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Yoshida, Hiroyuki, Atsushi Fujiwara, Kazuya Tamai, Naoki Kobayashi, Kazuhiko Saiki, and Koichi Saotome. "Diagnosis of Symptomatic Disc by Magnetic Resonance Imaging: T2-Weighted and Gadolinium-DTPA-Enhanced T1-Weighted Magnetic Resonance Imaging." Journal of Spinal Disorders & Techniques 15, no. 3 (June 2002): 193–98. http://dx.doi.org/10.1097/00024720-200206000-00004.

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Ohishi, Tsuyoshi, Masaaki Takahashi, Daisuke Suzuki, and Yukihiro Matsuyama. "Unusual Presentation of Popliteal Cyst on Magnetic Resonance Imaging." Case Reports in Orthopedics 2016 (2016): 1–4. http://dx.doi.org/10.1155/2016/1214030.

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Popliteal cyst commonly presents as an ellipsoid mass with uniform low signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images. Here, we describe a popliteal cyst with unusual appearance on magnetic resonance imaging, including heterogeneous intermediate signal intensity on T2-weighted images. Arthroscopic cyst decompression revealed that the cyst was filled with necrotic synovial villi, indicative of rheumatoid arthritis. Arthroscopic enlargement of unidirectional valvular slits with synovectomy was useful for the final diagnosis and treatment.

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Ji, Ding-Kun, Giacomo Reina, Hanyu Liang, Da Zhang, Shi Guo, Belén Ballesteros, Cécilia Ménard-Moyon, Juan Li, and Alberto Bianco. "Gadolinium-Incorporated Carbon Nanodots for T1-Weighted Magnetic Resonance Imaging." ACS Applied Nano Materials 4, no. 2 (January 15, 2021): 1467–77. http://dx.doi.org/10.1021/acsanm.0c02993.

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Agrawal, Amit, KishorV Hegde, UmamaheswaraV Reddy, SatishS Kumar, and MalleswaraG Rao. "High signal intervertebral disc in T1-weighted magnetic resonance imaging." Journal of Orthopaedics and Allied Sciences 3, no. 2 (2015): 79. http://dx.doi.org/10.4103/2319-2585.158519.

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Fukuda, Atsushi, Shinya Morita, Taisuke Harada, Keishi Fujiwara, Kimiko Hoshino, Yuji Nakamaru, and Akihiro Homma. "Value of T1-weighted Magnetic Resonance Imaging in Cholesteatoma Detection." Otology & Neurotology 38, no. 10 (December 2017): 1440–44. http://dx.doi.org/10.1097/mao.0000000000001558.

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Raithatha, A., and C. Narshi. "Axial T1 weighted magnetic resonance imaging of the female pelvis." BMJ 346, jun05 1 (June 5, 2013): f3512. http://dx.doi.org/10.1136/bmj.f3512.

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Peng, Yung-Kang, Shik Chi Edman Tsang, and Pi-Tai Chou. "Chemical design of nanoprobes for T1-weighted magnetic resonance imaging." Materials Today 19, no. 6 (July 2016): 336–48. http://dx.doi.org/10.1016/j.mattod.2015.11.006.

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Nakagawara, Masanori, Hiroyuki Hanai, and Masayoshi Kajimura. "Detection of Liver Abscesses by T1-Weighted Magnetic Resonance Imaging." New England Journal of Medicine 351, no. 10 (September 2, 2004): 1013. http://dx.doi.org/10.1056/nejmicm990183.

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Zeng, Leyong, Di Wu, Ruifen Zou, Tianxiang Chen, Jinchao Zhang, and Aiguo Wu. "Paramagnetic and Superparamagnetic Inorganic Nanoparticles for T1-Weighted Magnetic Resonance Imaging." Current Medicinal Chemistry 25, no. 25 (August 30, 2018): 2970–86. http://dx.doi.org/10.2174/0929867324666170314124616.

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Magnetic resonance imaging (MRI) has become a promising technique in the early diagnosis of cancers, especially the application of contrast agents can further enhance the detection limit. Compared with the dark signal in “negative” contrast agents (T2), “positive” contrast agents (T1) with bright signal are more desirable for high-resolution imaging. However, the clinically used gadolinium complexes have short circulation time and the risk of nephrogenic system fibrosis. Therefore, to overcome the disadvantage of T2 agents and traditional T1 agents, it is very interesting to develop nano-scaled T1-weighted MRI contrast agents with safer and more precise imaging performance. The present review systematically summarized the recent progress of paramagnetic and superparamagnetic inorganic nanoparticles as T1-weighted MRI contrast agents, including gadolinium oxide nanoparticles, gadoliniumbased upconversion nanoparticles, manganese oxide nanoparticles, and ultra-small iron oxide nanoparticles. Moreover, we also described their applications in multi-modal imaging and visualized theranostics.

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Tachibana, Osamu, Narihito Yamaguchi, Tetsumori Yamashima, and Junkoh Yamashita. "Radiation Necrosis of the Optic Chiasm, Optic Tract, Hypothalamus, and Upper Pons after Radiotherapy for Pituitary Adenoma, Detected by Gadolinium-Enhanced, T1-Weighted Magnetic Resonance Imaging: Case Report." Neurosurgery 27, no. 4 (October 1, 1990): 640–43. http://dx.doi.org/10.1227/00006123-199010000-00025.

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Abstract A 26-year-old woman was treated for a prolactin secreting pituitary adenoma by surgery and radiotherapy (5860 rads). Fourteen months later, she developed right hemiparesis and dysarthria. A T1-weighted magnetic resonance imaging scan using gadolinium contrast showed a small, enhanced lesion in the upper pons. Seven months later, she had a sudden onset of loss of vision, and radiation optic neuropathy was diagnosed. A T1-weighted magnetic resonance imaging scan showed widespread gadolinium-enhanced lesions in the optic chiasm, optic tract, and hypothalamus. Magnetic resonance imaging is indispensable for the early diagnosis of radiation necrosis, which is not visualized by radiography or computed tomography.

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Baird, Alison E., and Steven Warach. "Magnetic Resonance Imaging of Acute Stroke." Journal of Cerebral Blood Flow & Metabolism 18, no. 6 (June 1998): 583–609. http://dx.doi.org/10.1097/00004647-199806000-00001.

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In the investigation of ischemic stroke, conventional structural magnetic resonance (MR) techniques (e.g., T1-weighted imaging, T2-weighted imaging, and proton density-weighted imaging) are valuable for the assessment of infarct extent and location beyond the first 12 to 24 hours after onset, and can be combined with MR angiography to noninvasively assess the intracranial and extracranial vasculature. However, during the critical first 6 to 12 hours, the probable period of greatest therapeutic opportunity, these methods do not adequately assess the extent and severity of ischemia. Recent developments in functional MR imaging are showing great promise for the detection of developing focal cerebral ischemic lesions within the first hours. These include (1) diffusion-weighted imaging, which provides physiologic information about the self-diffusion of water, thereby detecting one of the first elements in the pathophysiologic cascade leading to ischemic injury; and (2) perfusion imaging. The detection of acute intraparenchymal hemorrhagic stroke by susceptibility weighted MR has also been reported. In combination with MR angiography, these methods may allow the detection of the site, extent, mechanism, and tissue viability of acute stroke lesions in one imaging study. Imaging of cerebral metabolites with MR spectroscopy along with diffusion-weighted imaging and perfusion imaging may also provide new insights into ischemic stroke pathophysiology. In light of these advances in structural and functional MR, their potential uses in the study of the cerebral ischemic pathophysiology and in clinical practice are described, along with their advantages and limitations.

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Kanberoglu, K., F. Kantarci, and M. H. Yilmaz. "Reactive sclerosis: hyperintense appearance on T2-weighted magnetic resonance imaging." Acta Radiologica 46, no. 7 (November 2005): 708–15. http://dx.doi.org/10.1080/02841850510021788.

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Osteosclerosis is defined as increased density of bone on X-ray imaging studies. It is known that osteosclerosis appears hypointense on both T1- and T2-weighted magnetic resonance imaging sequences. In this review, we present our experience in various sclerotic skeletal pathologies that appear hyperintense on T2-weighted magnetic resonance imaging. We emphasize the possible pathophysiological mechanisms that may cause this appearance, such as bone marrow edema and/or composition of newly formed bone.

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Ashraf, Yasma, Irum Iqbal, and Shafaat Khatoon. "MAGNETIC RESONANCE IMAGING;." Professional Medical Journal 24, no. 04 (April 6, 2017): 560–64. http://dx.doi.org/10.29309/tpmj/2017.24.04.1512.

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Perianal fistula is defined as an abnormal communication channel between analcanal and perianal skin. Among all the imaging tools Magnetic resonance imaging (MRI) isof choice in the diagnosis and management of perianal fistulas. Objectives: “To determinethe diagnostic accuracy of MR imaging in detection of perianal fistulas and comparing it withper operative findings”. Peroperative findings are taken as gold standard. Place and Durationof Study: This study was carried out in Diagnostic Radiology, Pakistan Institute of MedicalSciences (P.I.M.S) Islamabad, over a period of nine months from 01-02-2012 to 31-10-2012. Forthis collaboration was made with the Department of General Surgery P.I.M.S and Departmentof gynecology (MCH center) PIMS and gastroenterology Department. Patients and Methods:A total of 95 patients were included in study having perianal fistulas on clinical examination.MRI was performed in the patients and T1-weighted fast spin echo (T1W FSE) images weretaken before and after gadolinium injection. Fat suppressed T2-weighted fast spin echo (T2WFSE) images were obtained in all three planes including transverse, sagittal and coronal. Allthe scans were viewed by a single consultant radiologist to avoid observer bias. Results: Outof 95, 81 patients (85.3%) were male and 14 (14.7%) were female. Sensitivity, specificity andaccuracy of magnetic resonance imaging (MRI) was 96.2%, 75.0% and 92.6%, respectively.Positive predictive value was 95.0% and negative predictive value was 80.0%. Conclusion: ourstudy proves that among imaging modalities MRI is of choice for preoperative assessment ofperianal fistulas. It provides highly accurate, noninvasive and relatively very less time consumingmeans of performing pre-operative evaluation, specially the complex, branching fistulas. Thisdiagnostic accuracy not only helps in surgical cure but avoids recurrence and post-operativecomplications like fecal incontinence

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FUKUDA, Aya, Luciano de Souza QUEIROZ, and Fabiano REIS. "Gliosarcomas: magnetic resonance imaging findings." Arquivos de Neuro-Psiquiatria 78, no. 2 (February 2020): 112–20. http://dx.doi.org/10.1590/0004-282x20190158.

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Abstract Background: Central nervous system (CNS) gliosarcoma (GSM) is a rare primary neoplasm characterized by the presence of glial and sarcomatous components. Objective: In this report, we describe the clinical and neuroimaging aspects of three cases of GSM and correlate these aspects with pathological findings. We also provide a brief review of relevant literature. Methods: Three patients were evaluated with magnetic resonance imaging (MRI), and biopsies confirmed the diagnosis of primary GSM, without previous radiotherapy. Results: The analysis of conventional sequences (T1, T1 after contrast injection, T2, Fluid attenuation inversion recovery, SWI and DWI/ADC map) and advanced (proton 1H MR spectroscopy and perfusion) revealed an irregular, necrotic aspect of the lesion, peritumoral edema/infiltration and isointensity of the solid component on a T2-weighted image. These features were associated with irregular and peripheral contrast enhancement, lipid and lactate peaks, increased choline and creatine levels in proton spectroscopy, increased relative cerebral blood volume (rCBV) in perfusion, multifocality and drop metastasis in one of the cases. Conclusion: These findings are discussed in relation to the general characteristics of GSM reported in the literature.

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Dharsono, Ferry, Andrew Thompson, Jolandi van Heerden, and Andrew Cheung. "Susceptibility Weighted Imaging as a Useful Imaging Adjunct in Hemichorea Hyperglycaemia." Case Reports in Radiology 2013 (2013): 1–3. http://dx.doi.org/10.1155/2013/456156.

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Hyperglycaemia with hemichorea (HGHC) is an unusual clinical entity that can be associated with corpus striatum hyperintensity on T1-weighted (T1W) magnetic resonance imaging (MRI) sequences. We report the utility of the susceptibility weighted image (SWI) sequence and the filtered phase SWI sequence in the imaging assessment of HGHC.

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Ikuhiro, Kida, K. Maciejewski Paul, and Fahmeed Hyder. "Dynamic Imaging of Perfusion and Oxygenation by Functional Magnetic Resonance Imaging." Journal of Cerebral Blood Flow & Metabolism 24, no. 12 (December 2004): 1369–81. http://dx.doi.org/10.1097/01.wcb.0000141501.12558.9b.

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Cerebral blood flow can be measured with magnetic resonance imaging (MRI) by arterial spin labeling techniques, where magnetic labeling of flowing spins in arterial blood water functions as the endogenous tracer upon mixing with the unlabeled stationary spins of tissue water. The consequence is that the apparent longitudinal relaxation time (T1) of tissue water is attenuated. A modified functional MRI scheme for dynamic CBF measurement is proposed that depends on extraction of T1 weighting from the blood oxygenation level–dependent (BOLD) image contrast, because the functional MRI signal also has an intrinsic T1 weighting that can be altered by variations of the excitation flip angle. In the α-chloralose-anesthetized rat model at 7T, the authors show that the stimulation-induced BOLD signal change measured with two different flip angles can be combined to obtain a T1-weighted MRI signal, reflecting the magnitude of the CBF change, which can be deconvolved to obtain dynamic changes in CBF. The deconvolution of the T1-weighted MRI signal, which is a necessary step for accurate reflection of the dynamic changes in CBF, was made possible by a transfer function obtained from parallel laser-Doppler flowmetry experiments. For all stimulus durations (ranging from 4 to 32 seconds), the peak CBF response measured by MRI after the deconvolution was reached at 4.5 ± 1.0 seconds, which is in good agreement with (present and prior) laser-Doppler measurements. Because the low flip angle data can also provide dynamic changes of the conventional BOLD image contrast, this method can be used for simultaneous imaging of CBF and BOLD dynamics.

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Sui, Binbin, Xiaoyan Bai, Peiyi Gao, Yan Lin, Yisen Zhang, Jia Liang, and Xinjian Yang. "High-resolution vessel wall magnetic resonance imaging for depicting imaging features of unruptured intracranial vertebrobasilar dissecting aneurysms." Journal of International Medical Research 49, no. 2 (February 2021): 030006052097738. http://dx.doi.org/10.1177/0300060520977388.

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Objective To demonstrate the application value of high-resolution vessel wall magnetic resonance imaging (HR-VW-MRI) for depicting the imaging features of unruptured intracranial vertebrobasilar dissecting aneurysms (VBDAs). Methods HR-VW-MRI data of 49 patients with suspected unruptured VBDAs were retrospectively analyzed. The presence of intramural hematomas (IMH), double lumens, intimal flaps, and outer diameter enlargements were recorded. Specificity and sensitivity were calculated for both two-dimensional (2D) and three-dimensional (3D) sequences. Additionally, IMH volumes were measured and posterior inferior cerebellar artery (PICA) involvement was analyzed. Results Thirty-five VBDAs were confirmed in 34 patients. The overall sensitivity and specificity were 0.889 (95% confidence interval [CI]: 0.730–0.964) and 0.769 (95% CI: 0.460–0.938) for 2D sequences, and 0.917 (95% CI: 0.764–0.978) and 0.846 (95% CI: 0.537–0.973) for 3D sequences, respectively. Intimal flaps were detected in 57.1%, 87.5%, and 71.4% of all cases on 2D pre-contrast T1-weighted, contrast-enhanced T1-weighted, and 3D T1-weighted black-blood (BB) images, respectively. There was no significant difference in IMH volume between 3D T1-weighted BB and magnetization-prepared rapid gradient-echo sequences. PICA involvement was best visualized using 3D T1 sequences. Conclusion 3D T1-weighted BB MRI provided good visualization of VBDA features, with large coverage, and was useful for detecting dissection flaps.

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Takeuchi, Mayumi, Kenji Matsuzaki, Yoshimi Bando, and Masafumi Harada. "Reduced field-of-view diffusion-weighted MR imaging for assessing the local extent of uterine cervical cancer." Acta Radiologica 61, no. 2 (June 1, 2019): 267–75. http://dx.doi.org/10.1177/0284185119852733.

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Background Recently, the evaluation of the tumor size and local extension of early-stage uterine cervical cancer on magnetic resonance imaging is important for the accurate clinical staging and to determine the indication of less extensive surgery such as fertility sparing radical trachelectomy. Purpose To compare the diagnostic ability of reduced field-of-view diffusion-weighted imaging with those of three-dimensional (3D) contrast-enhanced T1-weighted imaging and T2-weighted imaging for assessing the tumor margin delineation and local extent of uterine cervical cancer. Material and Methods 3T magnetic resonance images, including T2-weighted imaging, reduced field-of-view diffusion-weighted imaging, and 3D contrast-enhanced T1-weighted imaging, in 27 women with surgically proven cervical cancer (19 FIGO stage IB1, 3 IB2, and 5 IIA1) were retrospectively evaluated. Tumor margins and local tumor extent, including the presence of invasion to parametrium and vagina were evaluated on both sagittal and oblique axial (short axis) images; the results were compared with histologically confirmed tumor extension. Results Reduced field-of-view diffusion-weighted imaging diagnosed the tumor margins, which was more accurate than T2-weighted imaging ( P<0.001) and slightly better than 3D contrast-enhanced T1-weighted imaging. Reduced field-of-view diffusion-weighted imaging could define the tumor margins well even in small lesions (≤ 20 mm). Histological examination revealed parametrial invasion in two cases (clinically under-staged) and vaginal invasion in four cases. Reduced field-of-view diffusion-weighted imaging could demonstrate local extension of all lesions, which was more accurate than clinical examination and T2-weighted imaging. Conclusion Addition of reduced field-of-view diffusion-weighted imaging may improve the staging accuracy of magnetic resonance imaging for cervical cancer in assessing the local tumor extent.

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Rana, Khizar, Valerie Juniat, Aaron Rayan, Sandy Patel, and Dinesh Selva. "Normative measurements of the superior oblique and inferior oblique muscles by magnetic resonance imaging." Surgical and Radiologic Anatomy 44, no. 4 (March 8, 2022): 521–25. http://dx.doi.org/10.1007/s00276-022-02915-w.

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Abstract Purpose Normative oblique muscle data may help to diagnose pathological enlargement of the oblique muscles. We aim to describe the normative values of the superior and inferior oblique muscles in an Australian cohort on T1-weighted MRI and fat suppressed contrast enhanced T1-weighted MRI. Methods A retrospective review of patients who underwent 3 T orbital MRI. The healthy orbits were used to conduct measurements in patients with a unilateral orbital lesion. The maximum diameters of the superior and inferior oblique muscles were measured on coronal planes. The diameter was measured perpendicular to the long axis of the muscles. Results The normal measurements (mean ± SD) on fat suppressed contrast enhanced T1-weighted MRI: superior oblique, 3.0 ± 0.5 mm and inferior oblique, 2.7 ± 0.5 mm. On T1-weighted MRI: superior oblique, 2.8 ± 0.5 mm and inferior oblique, 2.5 ± 0.4 mm. In patients who had both sequences performed, the superior and inferior oblique diameters were significantly higher on the fat suppressed contrast-enhanced T1-weighted MRI than the T1-weighted MRI sequence (p < 0.01). Conclusion Oblique muscle enlargement may be seen in a range of orbital diseases. These data may help in diagnosing oblique muscle enlargement. In addition, variations in the measured muscle diameters can be seen according to the scan sequence that is used.

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Hosoda, Kohkichi, Norihiko Tamaki, Michio Masumura, Satoshi Matsumoto, and Fumio Maeda. "Magnetic resonance images of chronic subdural hematomas." Journal of Neurosurgery 67, no. 5 (November 1987): 677–83. http://dx.doi.org/10.3171/jns.1987.67.5.0677.

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✓ Magnetic resonance imaging (MRI) and computerized tomography (CT) scans of 18 patients with 20 chronic subdural hematomas were compared. In many ways, MRI was superior to CT for demonstrating the hematomas. In general, chronic subdural hematomas were hyperintense on both T1- and T2-weighted MRI. The T1 values of chronic subdural hematomas were significantly shorter than gray matter values and significantly longer than white matter values. The T2 values were significantly longer than both gray matter and white matter values. These findings were consistent with previous reports. However, six hematomas (30%) were iso- or hypointense on T1-weighted images. Possible mechanisms responsible for the difference in intensity of chronic subdural hematoma on MRI are discussed, and the important role of methemoglobin formation is emphasized.

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Sandhu, Jagveer S., James R. McLaughlin, and Camilo R. Gomez. "Characteristics of Incidental Pineal Cysts on Magnetic Resonance Imaging." Neurosurgery 25, no. 4 (October 1, 1989): 636–40. http://dx.doi.org/10.1227/00006123-198910000-00020.

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Abstract Three patients with different neurological complaints were studied by magnetic resonance imaging. Coincidentally, all studies showed cystic changes within the pineal bodies. These cysts appeared hypointense on T1-weighted, spin-echo pulse sequences and hyperintense on T2-weighted images. Spin-density sequences displayed them as hypointense areas, with relaxation times similar to those of the CSF, suggesting their cystic nature. The increased use of magnetic resonance imaging may result in coincidental imaging of involutional cystic pineal changes of many individuals; their characteristic appearance will allow the differentiation between them and pineal neoplastic conditions.

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Saito, Atsushi, Kotoo Meguro, Akira Matsumura, Yoji Komatsu, and Noriyoshi Oohashi. "Magnetic Resonance Imaging of a Fat Embolism of the Brain: Case Report." Neurosurgery 26, no. 5 (May 1, 1990): 882–85. http://dx.doi.org/10.1227/00006123-199005000-00027.

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Abstract A 22-year-old man developed fat embolism syndrome. Although a computed tomographic (CT) scan of the brain showed nothing abnormal, a magnetic resonance imaging scan detected scattered spotty areas of low intensity on T1-weighted images and of high intensity on T2-weighted images. Magnetic resonance imaging is thought to be more sensitive than computed tomography in detecting cerebral fat embolism syndrome and correlates well with the clinical course.

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Zhalniarovich, Y., Z. Adamiak, A. Pomianowski, and M. Jaskólska. "Most commonly used sequences and clinical protocols for brain and spine magnetic resonance imaging allowing better identification of pathological changes in dogs." Polish Journal of Veterinary Sciences 16, no. 1 (March 1, 2013): 157–63. http://dx.doi.org/10.2478/pjvs-2013-0024.

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Abstract Magnetic resonance imaging is the best imaging modality for the brain and spine. Quality of the received images depends on many technical factors. The most significant factors are: positioning the patient, proper coil selection, selection of appropriate sequences and image planes. The present contrast between different tissues provides an opportunity to diagnose various lesions. In many clinics magnetic resonance imaging has replaced myelography because of its noninvasive modality and because it provides excellent anatomic detail. There are many different combinations of sequences possible for spinal and brain MR imaging. Most frequently used are: T2-weighted fast spin echo (FSE), T1- and T2-weighted turbo spin echo, Fluid Attenuation Inversion Recovery (FLAIR), T1-weighted gradient echo (GE) and spin echo (SE), high-resolution three-dimensional (3D) sequences, fat-suppressing short tau inversion recovery (STIR) and half-Fourier acquisition single-shot turbo spin echo (HASTE). Magnetic resonance imaging reveals neurologic lesions which were previously hard to diagnose antemortem.

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Rovira, Àlex, and Cristina Auger. "Role of Contrast-enhanced Magnetic Resonance Imaging in Multiple Sclerosis." European Neurological Review 7, no. 3 (2012): 181. http://dx.doi.org/10.17925/enr.2012.07.03.181.

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Magnetic resonance imaging (MRI) is an important diagnostic tool in different central nervous system (CNS) disorders including brain cancer and cerebrovascular, inflammatory and neurodegenerative diseases. The most commonly used MRI contrast agents are gadolinium-based compounds that have been successfully employed in combination with T1-weighted sequences to detect and monitor focal disease-related abnormalities. These gadolinium-based contrast agents facilitate the visualisation of areas of blood brain barrier disruption, show good performance in diagnostic procedures and present a favourable safety profile. In multiple sclerosis (MS), conventional MRI, including T2-weighted and gadolinium-enhanced T1-weighted sequences, is pivotal to diagnose and to monitor disease activity and progression. Advanced magnetic resonance (MR) techniques and new contrast agents are currently being developed to improve the ability to identify CNS structural and functional abnormalities in MS, which may better correlate with and predict the clinical course of the disease.

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Kongpromsuk, Sutasinee, Nantaporn Pitakvej, Nutchawan Jittapiromsak, and Supada Prakkamakul. "Detection of brain metastases using alternative magnetic resonance imaging sequences: a comparison between SPACE and VIBE sequences." Asian Biomedicine 14, no. 1 (July 13, 2020): 27–35. http://dx.doi.org/10.1515/abm-2020-0005.

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AbstractBackgroundAccurate identification of brain metastases is crucial for cancer treatment.ObjectivesTo compare the ability to detect brain metastases of two alternative types of contrast-enhanced three-dimensional (3D) T1-weighted sequences called SPACE (Sampling Perfection with Application optimized Contrasts using different flip angle Evolutions) and VIBE (Volumetric Interpolated Brain Sequence) on magnetic resonance imaging (MRI) at 3 tesla.MethodsBetween April 2017 and February 2018, 27 consecutive adult Thai patients with a total number of 424 brain metastases were retrospectively included. The patients underwent both contrast-enhanced 3D T1-weighted SPACE and 3D T1-weighted VIBE MRI sequences at 3 tesla. Two neuroradiology experts independently reviewed the images to determine the number of enhancing lesions on each sequence. Wilcoxon signed rank test was used to compare the difference between the numbers of detectable parenchymal enhancing lesions. Interobserver reliability was calculated using intraclass correlation.Results3D T1-weighted SPACE detected more parenchymal enhancing lesions than 3D T1-weighted VIBE (424 vs. 378 lesions, median 6 vs. 5, P = 0.008). Fifteen patients (55.6%) had equal number of parenchymal enhancing lesions between two sequences. 3D T1-weighted SPACE detected more parenchymal enhancing lesions (up to 9 more lesions) in 10 patients (37%), while 3D T1-weighted VIBE detected more enhancing lesions (up to 2 more lesions) in 2 patients (7.4%). Interobserver reliability between the readers was excellent.ConclusionContrast-enhanced 3D T1-weighted SPACE sequence demonstrates a higher ability to detect brain metastases than contrast-enhanced 3D T1-weighted VIBE sequence at 3 tesla.

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Pescatori, Lorenzo Carlo, Edoardo Savarino, Giovanni Mauri, Enzo Silvestri, Maurizio Cariati, Francesco Sardanelli, and Luca Maria Sconfienza. "Quantification of visceral adipose tissue by computed tomography and magnetic resonance imaging: reproducibility and accuracy." Radiologia Brasileira 52, no. 1 (February 2019): 1–6. http://dx.doi.org/10.1590/0100-3984.2017.0211.

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Abstract Objective: To evaluate the feasibility of quantifying visceral adipose tissue (VAT) on computed tomography (CT) and magnetic resonance imaging (MRI) scans, using freeware, as well as calculating intraobserver and interobserver reproducibility. Materials and Methods: We quantified VAT in patients who underwent abdominal CT and MRI at our institution between 2010 and 2015, with a maximum of three months between the two examinations. A slice acquired at the level of the umbilicus was selected. Segmentation was performed with the region growing algorithm of the freeware employed. Intraobserver and interobserver reproducibility were evaluated, as was the accuracy of MRI in relation to that of CT. Results: Thirty-one patients (14 males and 17 females; mean age of 57 ± 15 years) underwent CT and MRI (mean interval between the examinations, 28 ± 12 days). The interobserver reproducibility was 82% for CT (bias = 1.52 cm2; p = 0.488), 86% for T1-weighted MRI (bias = −4.36 cm2; p = 0.006), and 88% for T2-weighted MRI (bias = −0.52 cm2; p = 0.735). The intraobserver reproducibility was 90% for CT (bias = 0.14 cm2; p = 0.912), 92% for T1-weighted MRI (bias = −3,4 cm2; p = 0.035), and 90% for T2-weighted MRI (bias = −0.30 cm2; p = 0.887). The reproducibility between T1-weighted MRI and T2-weighted MRI was 87% (bias = −0.11 cm2; p = 0.957). In comparison with the accuracy of CT, that of T1-weighted and T2-weighted MRI was 89% and 91%, respectively. Conclusion: The program employed can be used in order to quantify VAT on CT, T1-weighted MRI, and T2-weighted MRI scans. Overall, the accuracy of MRI (in comparison with that of CT) appears to be high, as do intraobserver and interobserver reproducibility. However, the quantification of VAT seems to be less reproducible in T1-weighted sequences.

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Rebolleda, G., M. Suárez Figueroa, F. J. Muñoz-Negrete, and A. Rocamora. "Magnetic Resonance Imaging in Cavitary Choroidal Melanoma." European Journal of Ophthalmology 10, no. 4 (January 2000): 335–37. http://dx.doi.org/10.1177/112067210001000412.

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Purpose To report the development of a cavitary choroidal melanoma in a patient with nevus of Ota and describe its magnetic resonance imaging (MRI) features. Patient A 66-year-old man with right oculodermal melanocytosis and an ipsilateral choroidal cavitary melanoma was seen. Diagnosis was suspected on the clinical, ultrasonographic and MRI findings. Results T1-weighted image showed a hyperintense solid mass containing hypointense cystic-like spaces delineated by hyperintense septa with respect to the vitreous. The reverse image was observed on T2-weighted images. A choroidal melanoma comprising epithelioid and spindle cells with multilocular cavities was documented histopathologically. Conclusions There may be an association between cavitary melanoma and nevus of Ota. Characteristic MRI findings could be helpful in the differential diagnosis of cavitary uveal melanoma.

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Tomlinson, Frank H., Clifford R. Jack, and Patrick J. Kelly. "Sequential magnetic resonance imaging following stereotactic radiofrequency ventralis lateralis thalamotomy." Journal of Neurosurgery 74, no. 4 (April 1991): 579–84. http://dx.doi.org/10.3171/jns.1991.74.4.0579.

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✓ Serial postoperative magnetic resonance (MR) studies were obtained in 21 patients who underwent somatotopically placed stereotactic radiofrequency (rf) ventralis lateralis thalamotomy for the control of movement disorders. The MR studies were reviewed to determine the MR characteristics of early-phase (≤ 7 days) and late-phase (8 days to 5 months) lesions. Surgery was performed for the control of parkinsonian tremor (14 cases), intention tremor (six cases), and essential tremor (one case). Single rf lesions were made with an electrode (1.6 mm in diameter, 3 mm in tip length) heated to 78°C for 60 seconds. On MR images of the lesions, three distinct concentric zones were identified, described as follows (from the center outward). Zone 1 gives increased signal on long-relaxation time (TR) (T2-weighted) MR images in early- and late-phase lesions and decreased signal on short-TR (T1-weighted) MR images in early-phase lesions only. Zone 2 gives decreased signal on long-TR (T2-weighted) images in early- and late-phase lesions; it gives isointense signal on short-TR (T1-weighted) images in early-phase lesions only. Zone 3 gives increased signal on long-TR (T2-weighted) images in early-phase lesions only and decreased signal on short-TR (T1-weighted) MR images in early-phase lesions only. It is considered that in early-phase lesions, Zone 2, with a mean diameter of 7.3 mm on axial long-TR (T2-weighted) imaging, represents an area of hemorrhagic coagulation necrosis. In late-phase lesions, Zone 2, with a mean diameter of 5.0 mm on axial long-TR (T2-weighted) imaging, represents hemosiderin deposition. Zone 3 likely represents edema, and this zone disappears between the early and late periods. From regression analysis, lesion size began to stabilize at approximately 7 months with a mature lesion diameter of 3.3 mm. Long-term follow-up monitoring (median 16 months) showed good tremor control. Based on clinical and radiological findings, the authors conclude that forms of hemoglobin are suitable markers to assess the size of rf lesions. Serial MR imaging provides a noninvasive means of studying the evolution of rf thalamotomy lesions.

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Yang, Chang-Tong, Parasuraman Padmanabhan, and Balázs Z. Gulyás. "Gadolinium(iii) based nanoparticles for T1-weighted magnetic resonance imaging probes." RSC Advances 6, no. 65 (2016): 60945–66. http://dx.doi.org/10.1039/c6ra07782j.

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Zhu, Derong, Fuyao Liu, Lina Ma, Dianjun Liu, and Zhenxin Wang. "Nanoparticle-Based Systems for T1-Weighted Magnetic Resonance Imaging Contrast Agents." International Journal of Molecular Sciences 14, no. 5 (May 21, 2013): 10591–607. http://dx.doi.org/10.3390/ijms140510591.

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Lim, Eun-Kyung, Byunghoon Kang, Yuna Choi, Eunji Jang, Seungmin Han, Kwangyeol Lee, Jin-Suck Suh, Seungjoo Haam, and Yong-Min Huh. "Gadolinium-based nanoparticles for highly efficient T1-weighted magnetic resonance imaging." Nanotechnology 25, no. 24 (May 28, 2014): 245103. http://dx.doi.org/10.1088/0957-4484/25/24/245103.

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Herrero Hernandez, Elena, Maria Consuelo Valentini, and Gianluigi Discalzi. "T1-weighted Hyperintensity in Basal Ganglia at Brain Magnetic Resonance Imaging:." NeuroToxicology 23, no. 6 (December 2002): 669–74. http://dx.doi.org/10.1016/s0161-813x(02)00016-5.

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Gupta, K. L., F. Mihara, and A. M. Right. "NON-T1-WEIGHTED SPIN-ECHO MAGNETIC RESONANCE IMAGING WITH CONTRAST MATERIAL." Southern Medical Journal 84, Supplement (September 1991): 78. http://dx.doi.org/10.1097/00007611-199109001-00287.

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Cheng, Kai, Meng Yang, Ruiping Zhang, Chunxia Qin, Xinhui Su, and Zhen Cheng. "Hybrid Nanotrimers for Dual T1 and T2-Weighted Magnetic Resonance Imaging." ACS Nano 8, no. 10 (October 8, 2014): 9884–96. http://dx.doi.org/10.1021/nn500188y.

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Hahnemann, Maria L., Oliver Kraff, Stephan Orzada, Lale Umutlu, Sonja Kinner, Mark E. Ladd, Harald H. Quick, and Thomas C. Lauenstein. "T1-Weighted Contrast-Enhanced Magnetic Resonance Imaging of the Small Bowel." Investigative Radiology 50, no. 8 (August 2015): 539–47. http://dx.doi.org/10.1097/rli.0000000000000161.

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Journal articles on the topic 'T1-weighted magnetic resonance imaging'

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