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Journal articles on the topic 'Mri sequence optimization'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Prayoga, Aryadiva, Hermien Nugraheni, and Diyah Fatmasari. "Sequence application of Brain mri with orthodontic bracket." Jurnal Riset Kesehatan 9, no. 1 (May 1, 2020): 48–55. http://dx.doi.org/10.31983/jrk.v9i1.5690.

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Magnetic Resonance Imaging (MRI) examination of the brain at high resolution will be able to detect abnormalities in the brain that are not detected before. The MRI machine is equipped with a very strong magnetic force, therefore metal objects can interfere with the workings of the machine . Some patients, there may be a magnet in the body unnoticed, for example: orthodontic bracket. The purpose of this study was to analyze the effectiveness of sequences to reduce metal artifacts due to the installation of the Orthodontic Bracket. This type of research is a quantitative analytic with a quasi-experimental research design. The research design used was a one group pretest-posttest design to determine the optimization of the application of the Slice Encoding Metal Artifact Correction (SEMAC) and View Angle Tilting (VAT) sequences on Brain MRI with Orthodontic Bracket. The results showed that the SEMAC sequence combined with T2 TSE was able to reduce metal artifacts well. VAT sequences combined with T2 TSE were able to reduce metal artifacts quite well. A more optimal sequence to reduce metal artifacts is T2 TSE SEMAC, where the sequence is able to reveal thin structures that are not visible in the T2 TSE or T2 TSE VAT sequences.

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Wang, Chen, Lars Johansson, Andr� Western, Hans Fagertun, and H�kan Ahlstr�m. "Sequence optimization in mangafodipir trisodium-enhanced liver and pancreas MRI." Journal of Magnetic Resonance Imaging 9, no. 2 (February 1999): 280–84. http://dx.doi.org/10.1002/(sici)1522-2586(199902)9:2<280::aid-jmri19>3.0.co;2-h.

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Abreu Junior, Luiz de, Laiz Laura de Godoy, Luciana Pinheiro dos Santos Vaz, André Evangelista Torres, Angela Maria Borri Wolosker, Ulysses Santos Torres, and Maria Lucia Borri. "Optimization of magnetic resonance imaging protocol for the diagnosis of transient global amnesia." Radiologia Brasileira 52, no. 3 (June 2019): 161–65. http://dx.doi.org/10.1590/0100-3984.2018.0028.

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Abstract Objective: To emphasize the most appropriate magnetic resonance imaging (MRI) diffusion protocol for the detection of lesions that cause transient global amnesia, in order to perform an accurate examination, as well as to determine the ideal time point after the onset of symptoms to perform the examination. Materials and Methods: We evaluated five patients with a diagnosis of transient global amnesia treated between 2012 and 2015. We analyzed demographic characteristics, clinical data, symptom onset, diffusion techniques, and radiological findings. Examination techniques included a standard diffusion sequence (b value = 1000 s/mm2; slice thickness = 5 mm) and a optimized diffusion sequence (b value = 2000 s/mm2; slice thickness = 3 mm). Results: Brain MRI was performed at 24 h or 36 h after symptom onset, except in one patient, in whom it was performed at 12 h after (at which point no changes were seen) and repeated at 36 h after symptom onset (at which point it showed alterations in the right hippocampus). The standard and optimized diffusion sequences were both able to demonstrate focal changes in the hippocampi in all of the patients but one, in whom the changes were demonstrated only in the optimized sequence. Conclusion: MRI can confirm a clinical hypothesis of transient global amnesia. Knowledge of the optimal diffusion parameters and the ideal timing of diffusion-weighted imaging (> 24 h after symptom onset) are essential to improving diagnostic efficiency.

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Soltanian-Zadeh, H., R. Saigal, J. P. Windham, A. E. Yagle, and D. O. Hearshen. "Optimization of MRI protocols and pulse sequence parameters for eigenimage filtering." IEEE Transactions on Medical Imaging 13, no. 1 (March 1994): 161–75. http://dx.doi.org/10.1109/42.276155.

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Sinha, S., U. Sinha, R. Lufkin, and W. Hanafee. "Pulse sequence optimization for use with a biopsy needle in MRI." Magnetic Resonance Imaging 7, no. 5 (September 1989): 575–79. http://dx.doi.org/10.1016/0730-725x(89)90415-3.

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Gruwel, Marco L. H., Peter Latta, and Boguslaw Tomanek. "Improvements in MR imaging of solids through gradient waveform optimization." Canadian Journal of Chemistry 89, no. 7 (July 2011): 729–36. http://dx.doi.org/10.1139/v11-022.

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Magnetic resonance imaging (MRI) is known to provide a useful approach for the exploration of the chemistry and dynamics of a wide range of soft condensed materials. However, its application to solids has been limited to those materials with relatively narrow resonances. The time needed to obtain an image of a solid with a given resolution and signal-to-noise ratio (SNR) is directly proportional to the line width of the resonance. For MRI to become practical for the imaging of solids it will have to rely on the development and use of MR sequences that avoid the issues raised by line broadening of the resonance. In this paper we review the latest contributions towards MR imaging of solids from our laboratory, in particular, applications using optimized gradient waveforms. Acoustic noise reduction and SNR improvement obtained with modifications of the standard single-point imaging sequence are presented and discussed using examples.

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Inoue, Akitoshi, Akira Furukawa, Norihisa Nitta, Kai Takaki, Shinichi Ohta, and Kiyoshi Murata. "Optimization of pulse sequences in ultrafast magnetic resonance imaging for the diagnosis of acute abdominal pain caused by gastrointestinal disease." Acta Radiologica Open 9, no. 8 (August 2020): 205846012094924. http://dx.doi.org/10.1177/2058460120949246.

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Background Magnetic resonance imaging (MRI) is widely used to diagnose acute abdominal pain; however, it remains unclear which pulse sequence has priority in acute abdominal pain. Purpose To investigate the diagnostic accuracy of MRI and to assess the conspicuity of each pulse sequence for the diagnosis of acute abdominal pain due to gastrointestinal diseases Material and Methods We retrospectively enrolled 60 patients with acute abdominal pain who underwent MRI for axial and coronal T2-weighted (T2W) imaging, fat-suppressed (FS)-T2W imaging, and true-fast imaging with steady-state precession (True-FISP) and axial T1-weighted (T1W) imaging and investigated the diagnosis with endoscopy, surgery, histopathology, computed tomography, and clinical follow-up as standard references. Two radiologists determined the diagnosis with MRI and rated scores of the respective sequences in assessing intraluminal, intramural, and extramural abnormality using a 5-point scale after one month. Diagnostic accuracy was calculated and scores were compared by Wilcoxon-signed rank test with Bonferroni correction. Results Diagnostic accuracy was 90.0% and 93.3% for readers 1 and 2, respectively. Regarding intraluminal abnormality, T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in both readers. FS-T2W imaging was superior to True-FISP in reader 2 ( P < 0.0083). For intramural findings, there was no significant difference in reader 1, whereas T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in reader 2 ( P < 0.0083). For extramural findings, FS-T2W imaging was superior to T2W, T1W, and True-FISP imaging in both readers ( P < 0.0083). Conclusion T2W and FS-T2W imaging are pivotal pulse sequences and should be obtained before T1W and True-FISP imaging.

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He, Lili, Jinghua Wang, Zhong-Lin Lu, Beth M. Kline-Fath, and Nehal A. Parikh. "Optimization of magnetization-prepared rapid gradient echo (MP-RAGE) sequence for neonatal brain MRI." Pediatric Radiology 48, no. 8 (May 2, 2018): 1139–51. http://dx.doi.org/10.1007/s00247-018-4140-x.

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9

Mastropietro, Alfonso, Elisabetta De Bernardi, Gian Luca Breschi, Ileana Zucca, Massimo Cametti, Chiara Dolores Soffientini, Marco de Curtis, et al. "Optimization of rapid acquisition with relaxation enhancement (RARE) pulse sequence parameters for19F-MRI studies." Journal of Magnetic Resonance Imaging 40, no. 1 (November 13, 2013): 162–70. http://dx.doi.org/10.1002/jmri.24347.

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10

Niu, Junlong, Xiansheng Qin, Jing Bai, and Haiyan Li. "Reconstruction and optimization of the 3D geometric anatomy structure model for subject-specific human knee joint based on CT and MRI images." Technology and Health Care 29 (March 25, 2021): 221–38. http://dx.doi.org/10.3233/thc-218022.

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BACKGROUND: Nowadays, the total knee arthroplasty (TKA) technique plays an important role in surgical treatment for patients with severe knee osteoarthritis (OA). However, there are still several key issues such as promotion of osteotomy accuracy and prosthesis matching degree that need to be addressed. OBJECTIVE: It is significant to construct an accurate three-dimensional (3D) geometric anatomy structure model of subject-specific human knee joint with major bone and soft tissue structures, which greatly contributes to obtaining personalized osteotomy guide plate and suitable size of prosthesis. METHODS: Considering different soft tissue structures, magnetic resonance imaging (MRI) scanning sequences involving two-dimensional (2D) spin echo (SE) sequence T1 weighted image (T1WI) and 3D SE sequence T2 weighted image (T2WI) fat suppression (FS) are selected. A 3D modeling methodology based on computed tomography (CT) and two sets of MRI images is proposed. RESULTS: According to the proposed methods of image segmentation and 3D model registration, a novel 3D knee joint model with high accuracy is finally constructed. Furthermore, remeshing is used to optimize the established model by adjusting the relevant parameters. CONCLUSIONS: The modeling results demonstrate that reconstruction and optimization model of 3D knee joint can clearly and accurately reflect the key characteristics, including anatomical structure and geometric morphology for each component.

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Largent, A., L. Marage, I. Gicquiau, G. Gambarota, H. Chajon, O. Acosta, J. C. Nunes, R. De Crevoisier, and H. Saint-Jalmes. "EP-2348: MRI acquisition in radiotherapy treatment position: sequence optimization for head and neck cancer." Radiotherapy and Oncology 127 (April 2018): S1229. http://dx.doi.org/10.1016/s0167-8140(18)32657-4.

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Khodarahmi, Iman, Mathias Nittka, and Jan Fritz. "Leaps in Technology: Advanced MR Imaging after Total Hip Arthroplasty." Seminars in Musculoskeletal Radiology 21, no. 05 (October 12, 2017): 604–15. http://dx.doi.org/10.1055/s-0037-1606135.

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AbstractThe vast majority of the metal-related artifacts in magnetic resonance imaging (MRI) arise from B0 inhomogeneity. These artifacts include failed fat suppression, signal loss, signal pileup, and image distortions. Metal artifact reduction sequence MRI has been used to mitigate these artifacts via optimization of the scan parameters and exploiting new techniques such as fully phase-encoded imaging and multispectral imaging including multi-acquisition variable-resonance image combination and slice encoding for metal artifact correction. Applicability of MRI in the vicinity of metal implants has been revolutionized by these new techniques at the expense of longer acquisition times. To reach clinically viable scan times, these novel techniques have been successfully coupled with various acceleration paradigms such as parallel imaging and compressed sensing.

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Barrera, Christian A., Hansel J. Otero, Helge D. Hartung, David M. Biko, and Suraj D. Serai. "Protocol optimization for cardiac and liver iron content assessment using MRI: What sequence should I use?" Clinical Imaging 56 (July 2019): 52–57. http://dx.doi.org/10.1016/j.clinimag.2019.02.012.

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Beqiri, Arian, Anthony N. Price, Francesco Padormo, Joseph V. Hajnal, and Shaihan J. Malik. "Extended RF shimming: Sequence-level parallel transmission optimization applied to steady-state free precession MRI of the heart." NMR in Biomedicine 30, no. 6 (February 14, 2017): e3701. http://dx.doi.org/10.1002/nbm.3701.

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Ula, Kiki Rohmatul. "Optimalization Image Of Turbo Spin Echo (TSE) With Pre Saturation And Gradient Moment Nulling (GMN) To Reduce Flow Artifact On MRI Cervical." Jurnal Biosains Pascasarjana 21, no. 2 (August 1, 2019): 57. http://dx.doi.org/10.20473/jbp.v21i2.2019.57-70.

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ABSTRACTThe research of Optimization Image of Turbo Spin Echo (TSE) with Pre saturation and Gradient Moment Nulling (GMN) to reduce flow artifact on MRI Cervical has been done. The purpose of this research is to know the effect of pre saturation and gradient moment nulling (GMN) on cervical MRI and determine optimal image to reduce flow artifact. This research used four treatment variations that were without pre saturation and without flow compensation (GMN), with pre saturation, with flow compensation (GMN), and with both pre saturation and flow compensation (GMN) on sequence T2-weighting TSE sagital on cervical MRI. The quantitative analysis done by using Region of Interest (ROI) on MRI image then analyzed signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). The best effect and image quality obtained by pre saturation and flow compensation (GMN) treatment with SNR value on tissue was 328,7 at vertebra cervical, 278,6 at spinal cord, 366,6 at discus, 596,3 at CSF. While CNR tissue value was 78,6 at vertebra cervical, 257,6 at spinal cord, 274,8 at discus, and336,3 at CSF followed by the decrease of flow artifact in the amount of 160,4. Conclusion shows that the image with both pre saturation and flow compensation (GMN) treatment on T2 TSE sagital can reduce flow artifact signal on the spinal cord tissue. Keywords : Pre saturation, flow compensation, gradient moment nulling (GMN), MRI Cervical.

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Li, Jiahao, Weiyuan Huang, Xianfu Luo, Yan Wen, Junghun Cho, Ilhami Kovanlikaya, Susan A. Gauthier, Thanh D. Nguyen, Pascal Spincemaille, and Yi Wang. "The central vein sign in multiple sclerosis lesions: Susceptibility relaxation optimization from a routine MRI multiecho gradient echo sequence." Journal of Neuroimaging 32, no. 1 (October 19, 2021): 48–56. http://dx.doi.org/10.1111/jon.12938.

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Perkins, G., M. McGarry, T. Torfeh, R. Hammoud, D. Fierro, and N. Al Hammadi. "OC-0181: Optimization of a novel multi-echo 3D UTE volumetric sequence for tissue segmentation in MRI-only RT planning." Radiotherapy and Oncology 111 (2014): S71. http://dx.doi.org/10.1016/s0167-8140(15)30286-3.

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Jamárik, Jakub, Lubomír Vojtíšek, Vendula Churová, Tomáš Kašpárek, and Daniel Schwarz. "Identification of Laminar Composition in Cerebral Cortex Using Low-Resolution Magnetic Resonance Images and Trust Region Optimization Algorithm." Diagnostics 12, no. 1 (December 23, 2021): 24. http://dx.doi.org/10.3390/diagnostics12010024.

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Pathological changes in the cortical lamina can cause several mental disorders. Visualization of these changes in vivo would enhance their diagnostics. Recently a framework for visualizing cortical structures by magnetic resonance imaging (MRI) has emerged. This is based on mathematical modeling of multi-component T1 relaxation at the sub-voxel level. This work proposes a new approach for their estimation. The approach is validated using simulated data. Sixteen MRI experiments were carried out on healthy volunteers. A modified echo-planar imaging (EPI) sequence was used to acquire 105 individual volumes. Data simulating the images were created, serving as the ground truth. The model was fitted to the data using a modified Trust Region algorithm. In single voxel experiments, the estimation accuracy of the T1 relaxation times depended on the number of optimization starting points and the level of noise. A single starting point resulted in a mean percentage error (MPE) of 6.1%, while 100 starting points resulted in a perfect fit. The MPE was <5% for the signal-to-noise ratio (SNR) ≥ 38 dB. Concerning multiple voxel experiments, the MPE was <5% for all components. Estimation of T1 relaxation times can be achieved using the modified algorithm with MPE < 5%.

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Buck, Jessica, James R. Larkin, Manon A. Simard, Alexandre A. Khrapitchev, Michael A. Chappell, and Nicola R. Sibson. "Sensitivity of Multiphase Pseudocontinuous Arterial Spin Labelling (MP pCASL) Magnetic Resonance Imaging for Measuring Brain and Tumour Blood Flow in Mice." Contrast Media & Molecular Imaging 2018 (November 7, 2018): 1–11. http://dx.doi.org/10.1155/2018/4580919.

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Brain and tumour blood flow can be measured noninvasively using arterial spin labelling (ASL) magnetic resonance imaging (MRI), but reliable quantification in mouse models remains difficult. Pseudocontinuous ASL (pCASL) is recommended as the clinical standard for ASL and can be improved using multiphase labelling (MP pCASL). The aim of this study was to optimise and validate MP pCASL MRI for cerebral blood flow (CBF) measurement in mice and to assess its sensitivity to tumour perfusion. Following optimization of the MP pCASL sequence, CBF data were compared with gold-standard autoradiography, showing close agreement. Subsequently, MP pCASL data were acquired at weekly intervals in models of primary and secondary brain tumours, and tumour microvessel density was determined histologically. MP pCASL measurements in a secondary brain tumour model revealed a significant reduction in blood flow at day 35 after induction, despite a higher density of blood vessels. Tumour core regions also showed reduced blood flow compared with the tumour rim. Similarly, significant reductions in CBF were found in a model of glioma 28 days after tumour induction, together with an increased density of blood vessels. These findings indicate that MP pCASL MRI provides accurate and robust measurements of cerebral blood flow in naïve mice and is sensitive to changes in tumour perfusion.

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Hayashi, Norio, Kazuma Yarita, Kozue Sakata, Shunichi Motegi, Hiroyuki Nagase, Kouichi Ujita, Akio Ogura, Toshihiro Ogura, Takehiro Shimada, and Yoshito Tsushima. "Optimization method of MRI scan parameters of a double inversion recovery sequence using a T1 map and a developed analysis algorithm." Journal of X-Ray Science and Technology 25, no. 5 (October 19, 2017): 803–12. http://dx.doi.org/10.3233/xst-16243.

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Yoshizawa, Satoshi, Toshio Tsuchihashi, Satoshi Harashina, Akira Yoshimi, Kenichi Shimokawa, and Yoshio Matsumura. "Optimization of High Flip Angle for Late Gadolinium Enhancement Magnetic Resonance Imaging by Phase-Sensitive Inversion Recovery Sequence." Japanese Journal of Radiological Technology 69, no. 4 (2013): 380–85. http://dx.doi.org/10.6009/jjrt.2013_jsrt_69.4.380.

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22

Jungmann, Pia M., Carl Ganter, Christoph J. Schaeffeler, Jan S. Bauer, Thomas Baum, Reinhard Meier, Mathias Nittka, et al. "View-Angle Tilting and Slice-Encoding Metal Artifact Correction for Artifact Reduction in MRI: Experimental Sequence Optimization for Orthopaedic Tumor Endoprostheses and Clinical Application." PLOS ONE 10, no. 4 (April 24, 2015): e0124922. http://dx.doi.org/10.1371/journal.pone.0124922.

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Martín-González, Elena, Teresa Sevilla, Ana Revilla-Orodea, Pablo Casaseca-de-la-Higuera, and Carlos Alberola-López. "Groupwise Non-Rigid Registration with Deep Learning: An Affordable Solution Applied to 2D Cardiac Cine MRI Reconstruction." Entropy 22, no. 6 (June 19, 2020): 687. http://dx.doi.org/10.3390/e22060687.

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Groupwise image (GW) registration is customarily used for subsequent processing in medical imaging. However, it is computationally expensive due to repeated calculation of transformations and gradients. In this paper, we propose a deep learning (DL) architecture that achieves GW elastic registration of a 2D dynamic sequence on an affordable average GPU. Our solution, referred to as dGW, is a simplified version of the well-known U-net. In our GW solution, the image that the other images are registered to, referred to in the paper as template image, is iteratively obtained together with the registered images. Design and evaluation have been carried out using 2D cine cardiac MR slices from 2 databases respectively consisting of 89 and 41 subjects. The first database was used for training and validation with 66.6–33.3% split. The second one was used for validation (50%) and testing (50%). Additional network hyperparameters, which are—in essence—those that control the transformation smoothness degree, are obtained by means of a forward selection procedure. Our results show a 9-fold runtime reduction with respect to an optimization-based implementation; in addition, making use of the well-known structural similarity (SSIM) index we have obtained significative differences with dGW with respect to an alternative DL solution based on Voxelmorph.

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Arif, Muhammad, F. Ajesh, Shermin Shamsudheen, Oana Geman, Diana Izdrui, and Dragos Vicoveanu. "Brain Tumor Detection and Classification by MRI Using Biologically Inspired Orthogonal Wavelet Transform and Deep Learning Techniques." Journal of Healthcare Engineering 2022 (January 10, 2022): 1–18. http://dx.doi.org/10.1155/2022/2693621.

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Radiology is a broad subject that needs more knowledge and understanding of medical science to identify tumors accurately. The need for a tumor detection program, thus, overcomes the lack of qualified radiologists. Using magnetic resonance imaging, biomedical image processing makes it easier to detect and locate brain tumors. In this study, a segmentation and detection method for brain tumors was developed using images from the MRI sequence as an input image to identify the tumor area. This process is difficult due to the wide variety of tumor tissues in the presence of different patients, and, in most cases, the similarity within normal tissues makes the task difficult. The main goal is to classify the brain in the presence of a brain tumor or a healthy brain. The proposed system has been researched based on Berkeley’s wavelet transformation (BWT) and deep learning classifier to improve performance and simplify the process of medical image segmentation. Significant features are extracted from each segmented tissue using the gray-level-co-occurrence matrix (GLCM) method, followed by a feature optimization using a genetic algorithm. The innovative final result of the approach implemented was assessed based on accuracy, sensitivity, specificity, coefficient of dice, Jaccard’s coefficient, spatial overlap, AVME, and FoM.

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Pham, Dzung, Jerry L. Prince, Chenyang Xu, and Azar P. Dagher. "An Automated Technique for Statistical Characterization of Brain Tissues in Magnetic Resonance Imaging." International Journal of Pattern Recognition and Artificial Intelligence 11, no. 08 (December 1997): 1189–211. http://dx.doi.org/10.1142/s021800149700055x.

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A procedure for estimating the joint probability density function (pdf) of T1, T2 and proton spin density (PD) for gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in the brain is presented. The pdf's have numerous applications, including the study of tissue parameter variability in pathology and across populations. The procedure requires a multispectral, spin echo magnetic resonance imaging (MRI) data set of the brain. It consists of five automated steps: (i) preprocess the data to remove extracranial tissue using a sequence of image processing operators; (ii) estimate T1, T2 and PD by fitting the preprocessed data to an imaging equation; (iii) perform a fuzzy c-means clustering on the same preprocessed data to obtain a spatial map representing the membership value of the three tissue classes at each pixel location; (iv) reject estimates which are not from pure tissue or have poor fits in the parameter estimation, and classify the remaining estimates as either GM, WM or CSF; (v) compute statistics on the classified estimates to obtain a probability mass function and a Gaussian joint pdf of the tissue parameters for each tissue class. Some preliminary results are shown comparing computed pdf's of young, elderly and Alzheimer's subjects. Two brief examples applying the joint pdf's to pulse sequence optimization and generation of computational phantoms are also provided.

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Kubicek, Penhaker, Augustynek, Cerny, and Oczka. "Segmentation of Articular Cartilage and Early Osteoarthritis based on the Fuzzy Soft Thresholding Approach Driven by Modified Evolutionary ABC Optimization and Local Statistical Aggregation." Symmetry 11, no. 7 (July 2, 2019): 861. http://dx.doi.org/10.3390/sym11070861.

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Articular cartilage assessment, with the aim of the cartilage loss identification, is a crucial task for the clinical practice of orthopedics. Conventional software (SW) instruments allow for just a visualization of the knee structure, without post processing, offering objective cartilage modeling. In this paper, we propose the multiregional segmentation method, having ambitions to bring a mathematical model reflecting the physiological cartilage morphological structure and spots, corresponding with the early cartilage loss, which is poorly recognizable by the naked eye from magnetic resonance imaging (MRI). The proposed segmentation model is composed from two pixel’s classification parts. Firstly, the image histogram is decomposed by using a sequence of the triangular fuzzy membership functions, when their localization is driven by the modified artificial bee colony (ABC) optimization algorithm, utilizing a random sequence of considered solutions based on the real cartilage features. In the second part of the segmentation model, the original pixel’s membership in a respective segmentation class may be modified by using the local statistical aggregation, taking into account the spatial relationships regarding adjacent pixels. By this way, the image noise and artefacts, which are commonly presented in the MR images, may be identified and eliminated. This fact makes the model robust and sensitive with regards to distorting signals. We analyzed the proposed model on the 2D spatial MR image records. We show different MR clinical cases for the articular cartilage segmentation, with identification of the cartilage loss. In the final part of the analysis, we compared our model performance against the selected conventional methods in application on the MR image records being corrupted by additive image noise.

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Glaser, C., S. Faber, F. Eckstein, H. Fischer, V. Springer, L. Heudorfer, T. Stammberger, K. H. Englmeier, and M. Reiser. "Optimization and validation of a rapid high-resolution T1-w 3D FLASH water excitation MRI sequence for the quantitative assessment of articular cartilage volume and thickness." Magnetic Resonance Imaging 19, no. 2 (February 2001): 177–85. http://dx.doi.org/10.1016/s0730-725x(01)00292-2.

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Friesen, A., J. Radford, S. Chan, N. Mardis, and V. Shakhnovich. "O28 Variability in liver anatomy and physiology in children participating in pharmacokinetic studies." Archives of Disease in Childhood 104, no. 6 (May 17, 2019): e12.2-e13. http://dx.doi.org/10.1136/archdischild-2019-esdppp.28.

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BackgroundObesity-related changes in liver anatomy and physiology (e.g., hepatic fat infiltration) may be important sources of interindivdual variability in hepatic drug metabolism and relevant covariates for physiologically-based pharmacokinetic (PBPK) models. The aim of this investigation was to quantify variability in hepatic fat fraction (HFF) and hepatic volume in children participating in PK studies, utilizing a novel, non-invasive, magnetic resonance imaging (MRI) sequence.1MethodsChildren, without a known diagnosis of fatty liver disease, enrolled in a PK study for hepatic CYP2C19 and CYP3A4 substrates, had hepatic volume and total HFF estimated using MRI proton density fat fraction (PDFF) and HFF assessed via conventional MRI spectroscopy (MRSFF) using a region of interest in the right upper hepatic lobe (LiverLab, Siemens Healthcare). Patient anthropometrics, laboratories and LiverLab outcomes were compared between obese and non-obese children, using independent student t-test, and associations explored via Spearman’s correlation (ρ); SPSSv24, α=0.05. Obesity was defined by body mass index (BMI)≥95th percentile for age; clinically significant liver adiposity defined as HFF>5%.Results25 children (7–20 years; 56% obese) had evaluable MRI data. Liver volume ranged 911–2227cm3, MRSFF 1.6–34.8% and PDFF 2.1–31.1%. Liver volume and HFF significantly correlated with BMI (both ρ=0.6, p< 0.01), but not age (both ρ=0.3, p>0.11). Liver volume (1574.5±367.1 vs 1284.8±216.3, p=0.04), MRSFF (8.9±8.4 vs 2.8±1.2, p=0.02), PDFF (8.9±7.0 vs 3.4±1.3, p=0.07) and alanine aminotransferase (ALT; 37.7±15.8 vs 26.8±3.6 IU/L, p=0.02) were higher in obese vs non-obese children. HFF>5% and ALT> 40 were only observed in obese children.ConclusionLiver volume and adiposity varied substantially among children and may be important covariates for pediatric PBPK models, especially for obese children. HFF> 5% and ALT> 40 were only observed in obese children. Recently, 24% reduction in clearance of azithromycin, a CYP3A4 substrate, was reported for children with ALT> 40.2 Our PK analyses are in progress.ReferencesCaussy C, Reeder SB, Sirlin CB, et al. Noninvasive, quantitative assessment of liver fat by MRI-PDFF as as endpoint in NASH trials. Haptology 2018;68(2):763–72.Zheng Y, Liu SP, Xu BP, et al. Population Pharmacokinetics and Dosing Optimization of Azithromycin in Children with Community-Acquired Pneumonia. Antimicrob Agents Chemother 2018;62 (9):e00686–18.Disclosure(s)Nothing to disclose

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Olsson, Hampus, Mikael Novén, Jimmy Lätt, Ronnie Wirestam, and Gunther Helms. "Radiofrequency Bias Correction of Magnetization Prepared Rapid Gradient Echo MRI at 7.0 Tesla Using an External Reference in a Sequential Protocol." Tomography 7, no. 3 (September 13, 2021): 434–51. http://dx.doi.org/10.3390/tomography7030038.

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At field strengths of 7 T and above, T1-weighted imaging of human brain suffers increasingly from radiofrequency (RF) B1 inhomogeneities. The well-known MP2RAGE (magnetization prepared two rapid acquisition gradient echoes) sequence provides a solution but may not be readily available for all MR systems. Here, we describe the implementation and evaluation of a sequential protocol to obtain normalized magnetization prepared rapid gradient echo (MPRAGE) images at 0.7, 0.8, or 0.9-mm isotropic spatial resolution. Optimization focused on the reference gradient-recalled echo (GRE) that was used for normalization of the MPRAGE. A good compromise between white-gray matter contrast and the signal-to-noise ratio (SNR) was reached at a flip angle of 3° and total scan time was reduced by increasing the reference voxel size by a factor of 8 relative to the MPRAGE resolution. The average intra-subject coefficient-of-variation (CV) in segmented white matter (WM) was 7.9 ± 3.3% after normalization, compared to 20 ± 8.4% before. The corresponding inter-subject average CV in WM was 7.6 ± 7.6% and 13 ± 7.8%. Maps of T1 derived from forward signal modelling showed no obvious bias after correction by a separately acquired flip angle map. To conclude, a non-interleaved acquisition for normalization of MPRAGE offers a simple alternative to MP2RAGE to obtain semi-quantitative purely T1-weighted images. These images can be converted to T1 maps, analogously to the established MP2RAGE approach. Scan time can be reduced by increasing the reference voxel size which has only a miniscule effect on image quality.

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Nagarajan, Rajakumar, Saadallah Ramadan, and M. Albert Thomas. "Detection of Amide and Aromatic Proton Resonances of Human Brain Metabolites Using Localized Correlated Spectroscopy Combined with Two Different Water Suppression Schemes." Magnetic Resonance Insights 4 (January 2010): MRI.S4739. http://dx.doi.org/10.4137/mri.s4739.

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The purpose of the study was to demonstrate the J-coupling connectivity network between the amide, aliphatic, and aromatic proton resonances of metabolites in human brain using two-dimensional (2D) localized correlated spectroscopy (L-COSY). Two different global water suppression techniques were combined with L-COSY, one before and another after localizing the volume of interest (VOI). Phantom solutions containing several cerebral metabolites at physiological concentrations were evaluated initially for sequence optimization. Nine healthy volunteers were scanned using a 3T whole body MRI scanner. The VOI for 2D L-COSY was placed in the right occipital white/gray matter region. The 2D cross and diagonal peak volumes were measured for several metabolites such as N-acetyl aspartate (NAA), creatine (Cr), free choline (Ch), glutamate/glutamine (Glx), aspartate (Asp), myo-inositol (mI), GABA, glutathione (GSH), phosphocholine (PCh), phosphoethanolamine (PE), tyrosine (Tyr), lactate (Lac), macromolecules (MM) and homocarnosine (Car). Using the pre-water suppression technique with L-COSY, the above mentioned metabolites were clearly identifiable and the relative ratios of metabolites were calculated. In addition to detecting multitude of aliphatic resonances in the high field region, we have demonstrated that the amide and aromatic resonances can also be detected using 2D L-COSY by pre water suppression more reliably than the post-water suppression.

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Yao, Xiaopeng, Xinqiao Huang, Chunmei Yang, Anbin Hu, Guangjin Zhou, Jianbo Lei, and Jian Shu. "A Novel Approach to Assessing Differentiation Degree and Lymph Node Metastasis of Extrahepatic Cholangiocarcinoma: Prediction Using a Radiomics-Based Particle Swarm Optimization and Support Vector Machine Model." JMIR Medical Informatics 8, no. 10 (October 5, 2020): e23578. http://dx.doi.org/10.2196/23578.

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Background Radiomics can improve the accuracy of traditional image diagnosis to evaluate extrahepatic cholangiocarcinoma (ECC); however, this is limited by variations across radiologists, subjective evaluation, and restricted data. A radiomics-based particle swarm optimization and support vector machine (PSO-SVM) model may provide a more accurate auxiliary diagnosis for assessing differentiation degree (DD) and lymph node metastasis (LNM) of ECC. Objective The objective of our study is to develop a PSO-SVM radiomics model for predicting DD and LNM of ECC. Methods For this retrospective study, the magnetic resonance imaging (MRI) data of 110 patients with ECC who were diagnosed from January 2011 to October 2019 were used to construct a radiomics prediction model. Radiomics features were extracted from T1-precontrast weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI) using MaZda software (version 4.6; Institute of Electronics, Technical University of Lodz). We performed dimension reduction to obtain 30 optimal features of each sequence, respectively. A PSO-SVM radiomics model was developed to predict DD and LNM of ECC by incorporating radiomics features and apparent diffusion coefficient (ADC) values. We randomly divided the 110 cases into a training group (88/110, 80%) and a testing group (22/110, 20%). The performance of the model was evaluated by analyzing the area under the receiver operating characteristic curve (AUC). Results A radiomics model based on PSO-SVM was developed by using 110 patients with ECC. This model produced average AUCs of 0.8905 and 0.8461, respectively, for DD in the training and testing groups of patients with ECC. The average AUCs of the LNM in the training and testing groups of patients with ECC were 0.9036 and 0.8889, respectively. For the 110 patients, this model has high predictive performance. The average accuracy values of the training group and testing group for DD of ECC were 82.6% and 80.9%, respectively; the average accuracy values of the training group and testing group for LNM of ECC were 83.6% and 81.2%, respectively. Conclusions The MRI-based PSO-SVM radiomics model might be useful for auxiliary clinical diagnosis and decision-making, which has a good potential for clinical application for DD and LNM of ECC.

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Кравец, О., O. Kravets, А. Дубинина, A. Dubinina, Е. Тарачкова, E. Tarachkova, О. Козлов, O. Kozlov, Е. Романова, and E. Romanova. "Brachytherapy for Locally Advanced Cervix Cancer (Methodological Aspects)." Medical Radiology and radiation safety 64, no. 5 (October 21, 2019): 76–80. http://dx.doi.org/10.12737/1024-6177-2019-64-5-76-80.

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Purpose: To increase local control of cervical tumors by developing and introducing into practice the optimization of dose distribution in the primary tumor during concomitant chemoradiation (CRT) and image-guided adaptive brachytherapy (IGABT) i.e. summing up the maximum dose to the tumor volume of HR-CTV> 85 Gy in the shortest possible period of time by the optimal fractionation regime, without increasing the tolerable doses to the organs of risk (bladder, rectum, sigmoid). Material and methods: Data of the study was the of clinical observations of patients with locally advanced cervical cancer proven stage IIb–IIIb according to FIGO, treated with curative radiation therapy. After pelvic +/- para-aortic external-beam radiation therapy (2 Gy × 50 Gy with Cisplatin 40 mg/m2 weekly), they received high-dose rate intracavitary brachytherapy or in combination with interstitial component following GEC-ESTRO recommendations. Results: We managed to achieve maximum dose to the tumor volume of HR-CTV> 85 Gy without increasing the load on the risk organs. The Clinical Contouring at the time of primary diagnosis of cervical cancer and before brachytherapy session based on clinical and diagnostic data using MRI helps to optimize the brachytherapy process, develop patient management tactics and a clear sequence of actions in a complex program of brachytherapy. Conclusion: The presented clinical cases indicate the prospects of using an individual approach in planning the brachytherapy of patients with locally advanced cervical cancer.

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Roy, Subhankar, Jianping Hu, and M. Ummal Momeen. "Optimization of Pulse Sequences in MRI Scheme." Journal of Physics: Conference Series 1000 (April 2018): 012126. http://dx.doi.org/10.1088/1742-6596/1000/1/012126.

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Jambor, Ivan. "Optimization of prostate MRI acquisition and post-processing protocol: a pictorial review with access to acquisition protocols." Acta Radiologica Open 6, no. 12 (December 2017): 205846011774557. http://dx.doi.org/10.1177/2058460117745574.

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The aim of this review article is to provide insight into the optimization of 1.5-Testla (T) and 3-T prostate magnetic resonance imaging (MRI). An approach for optimization of data quantification, especially diffusion-weighted imaging (DWI), is provided. Benefits and limitations of various pulse sequences are discussed. Importable MRI protocols and access to imaging datasets is provided. Careful optimization of prostate MR acquisition protocol allows the acquisition of high-quality prostate MRI using clinical 1.5-T/3-T MR scanners with an overall acquisition time < 15 min.

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Zhang, Rosaline, Hyunyeol Lee, Xia Zhao, Hee K. Song, Felix W. Wehrli, and Scott P. Bartlett. "2118 Solid-state MRI as a nonradiative alternative to computed tomography for craniofacial imaging." Journal of Clinical and Translational Science 2, S1 (June 2018): 28. http://dx.doi.org/10.1017/cts.2018.123.

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OBJECTIVES/SPECIFIC AIMS: Computed tomography (CT) enables 3-dimensional (3D) visualization of cortical bone structures with high spatial resolution, and thus has been the gold-standard method for evaluation and diagnosis of craniofacial skeletal pathologies. However, ionizing radiation and, in particular, repeated scanning for presurgery and postsurgery assessments, is of concern when applied to infants and young children. Recent advances in solid-state MRI allow the capture of the short-T2 signals in cortical bone while suppressing the signal from soft-tissue protons having T2 relaxation time 1–2 orders of magnitude longer (50–100 ms). One approach, a dual-radiofrequency (RF) pulse and ultrashort echo time (UTE) imaging based method, exploits different sensitivities of bone and soft tissue to different RF pulse widths and TEs. This study aims to demonstrate the feasibility of producing 3D renderings of the human skull and visualization of cranial sutures using the bone-selective MRI technique in comparison to CT. METHODS/STUDY POPULATION: Imaging technique: Two RF pulses differing in duration and amplitude are alternately applied in successive repetition time (TR) along the pulse train. Within each TR, 2 echoes are acquired. Acquisition of the first echo starts at the ramp-up of the encoding gradient (TE1), allowing for capture of signals with very short lifetimes (bone), while that of the second starts after a longer delay (TE2). In total, 4 echoes are obtained: ECHO11 (RF1TE1), ECHO12 (RF1TE2), ECHO21 (RF2TE1), and ECHO22 (RF2TE2). During reconstruction, ECHO11 is combined with ECHO21 and ECHO12 is combined with ECHO22, resulting in 2 images. The subtraction of these 2 images yields an enhanced bone contrast. Data acquisition/processing: The pulse sequence described above was applied for MR imaging of a human cadaveric skull and 2 adult human subjects in vivo, at 3T field strength (Siemens Prisma, Erlangen, Germany). Imaging parameters: TR/TE1/TE2=7/0.06/2.46 ms, RF1/RF2 durations=40/520 μs, flip angle=12°, matrix size=2563, field of view=2803 mm3, voxel size=1.1 mm isotropic, number of radial spokes=25,000, and scan time=6 minutes. Segmentation of bone voxels was performed using ITK-SNAP in a semi-automatic fashion, leading to 3D renderings of the skull. For comparison, a CT scan was also performed in the human cadaveric skull with 1 mm isotropic resolution. Validation: The biometric accuracy was assessed by measuring eight anatomic distances: (1) Maximum craniocaudal aperture of the right orbit. (2) Maximum craniocaudal aperture of the left orbit. (3) Maximum height of the mandible from chin point in the midline. (4) Maximum cranial length (5) Maximum cranial width. (6) Maximum height of piriform aperture. (7) Distance between lateral most aspect of mandibular condyles. (8) Distance between lateral most aspect of posterior hard palate in both CT- and MRI-based 3D renderings of the human cadaveric skull using Mimics software (Materialise®, Ghent, Belgium). These distances were compared with those directly measured on the cadaveric skull. RESULTS/ANTICIPATED RESULTS: Compares CT with the proposed MRI method on cadaveric human skull images, along with corresponding 3D renderings. Compared with CT, the 3D rendered images maintain most features over the entire head (e.g., zygomatic arch), except for appearance of some artifacts in the mandibular region. In vivo head images in 2 adult subjects: axial magnitude images and 3D rendering. In the axial images, bone voxels as well as the inner table of the cranium are clearly visualized, and cranial and spinal bone structures are well depicted in the 3D renderings. Some voxels were erroneously included or excluded in the renderings. The mean difference in measurements of the 8 anatomic distances was 6, 4, and 2 mm when comparing MRI Versus CT, MRI Versus in situ, and CT Versus in situ, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: Bone proton magnetization exhibits a substantial level of signal decay during the relatively long duration of RF2 due to its very short T2 relaxation time. In contrast, soft-tissue retains nearly the same level of signal intensities over all echoes. Thus, subtraction of ECHO22 from ECHO11, when compared with the difference between ECHO11 and ECHO12, enhances bone contrast from soft tissue. The proposed, dual-RF dual-echo 3D UTE imaging technique produces isotropic high-resolution bone-specified images in the whole head within a clinically feasible imaging time (6 min), leading to clear visualization of craniofacial skeletal structures. These are key components necessary for translation to the clinical setting. Optimization of postprocessing for more realistic 3D renderings and thus accurate anatomic measurements is currently being implemented. The proposed method’s potential as a nonradiative alternative to CT will then be thoroughly evaluated in pediatric patients.

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Somai, Vencel, Felix Kreis, Adam Gaunt, Anastasia Tsyben, Ming Li Chia, Friederike Hesse, Alan J. Wright, and Kevin M. Brindle. "Genetic algorithm‐based optimization of pulse sequences." Magnetic Resonance in Medicine 87, no. 5 (December 6, 2021): 2130–44. http://dx.doi.org/10.1002/mrm.29110.

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Lomas, D. J. "Optimization of sequences for MRI of the abdomen and pelvis." Clinical Radiology 52, no. 6 (June 1997): 412–28. http://dx.doi.org/10.1016/s0009-9260(97)80002-5.

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Bergen, T. A., V. A. Fokin, and G. E. Trufanov. "Optimization of follow-up MRI protocol for malignant neoplasms of the female pelvis." Diagnostic radiology and radiotherapy 12, no. 1 (March 20, 2021): 7–13. http://dx.doi.org/10.22328/2079-5343-2021-12-1-7-13.

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Introduction. MRI is widely used to follow-up malignant neoplasms of the female pelvis. Aim. To optimize the use of MRI sequences for follow-up of female patients with malignant pelvic neoplasms. Materials and methods. Retrospective analysis of female pelvic MRI has been performed on 1.5 T MR scanner. This study includes 530 protocols. Results. The authors describe different protocols for assessment and differential diagnosis of recurrence, postradiation and postoperative changes. It includes applicable sequences, axis and the structure which require evaluation. In all cases, dynamic follow-up has to include analysis of patient's previous studies, anamnesis, previous treatment, as well as the end of chemotherapy and radiotherapy. All of the above, combined with the oncologist's treatment of choice determines the objective of this study. Nowadays, MRI is the method which most accurately characterizes postoperative and postradiation structural changes. MRI is useful in detection of pelvic lymph nodes. The role of MRI has high potential in assessing the effectiveness of chemotherapy and radiation therapy. Conclusion. In order to make the optimal scan protocol, follow-up of malignant neoplasms of the pelvic organs in women require the use of clinical and anamnestic data along with the results of patient's previous studies. The combined use of various sequences and techniques can improve the diagnostic significance of pelvic MRI at follow-up. Contrast enhancement has additional role in diagnostics of recurrent of pelvic organs in women. The use of different contrast enhancement techniques has proven effective in case of postradiation and postoperative complications.

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Chai, Jyh-Wen, Hong N. Yeung, Norbert J. Pelc, and Thilaka S. Sumanaweera. "T1-weighted signal contrast optimization by rf pulse sequences." Magnetic Resonance in Medicine 34, no. 1 (July 1995): 133–35. http://dx.doi.org/10.1002/mrm.1910340120.

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ADACHI, Satoru, and Takafumi KATSUSHIMA. "Fast imaging and optimization of cryospheric MRI sequences for wet snow." Journal of the Japanese Society of Snow and Ice 83, no. 6 (November 15, 2021): 569–78. http://dx.doi.org/10.5331/seppyo.83.6_569.

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Campbell, R. S. D., and A. J. Grainger. "Optimization of MRI pulse sequences to visualize the normal pars interarticularis." Clinical Radiology 54, no. 1 (January 1999): 63–68. http://dx.doi.org/10.1016/s0009-9260(99)91242-4.

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Schaefer, Christopher W., Deepika Lal, R. Robert Vethanayagam, Joseph A. Spernyak, Mukund Seshadri, and Eunice S. Wang. "Anti-Vascular and Anti-Tumor Effects of the Vascular Disrupting Agent ASA404 (DMXAA) in Human Acute Leukemia Xenograft Models." Blood 118, no. 21 (November 18, 2011): 4293. http://dx.doi.org/10.1182/blood.v118.21.4293.4293.

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Abstract Abstract 4293 Acute leukemia growth and expansion within the marrow microenvironment is linked to increased vascularization. Vascular delivery of chemotherapy drugs within the marrow space may also be an important mediator of anti-leukemic activity. We examined the effects of a tumor -vascular disrupting agent (tumor-VDA), ASA404 (DMXAA; Vadimezan), against human acute leukemia alone and in combination with anthracycline therapy. Exposure of human acute leukemia cells (HEL, Raji) to ASA404 (200–1000 mM) in vitro for up to 72 hours resulted in no evidence of direct cytotoxicity. However, contrast-enhanced magnetic resonance imaging (CE-MRI) performed in mice bearing subcutaneous HEL xenografts revealed an early increase in vascular permeability 4 hours after treatment with a single dose of ASA404 (25 mg/kg). This was followed by significant vascular disruption at 24 hours after therapy as determined by tumor immunohistochemistry. In systemic leukemia xenograft models established with luciferase-transfected HEL and Raji cells, continuous ASA404 treatment (20 mg/kg twice weekly) slowed overall systemic leukemia disease progression (as determined by whole animal bioluminescent imaging) in association with marked marrow vessel dilation, loss of vascular patency, and marked erythrocyte extravasation within the marrow microenvironment. These effects were accompanied by 20–30-fold elevations of circulating systemic TNF-alpha levels in ASA404 versus vehicle treated animals. Combining in vivo ASA404 treatment with anti-human VEGF antibody (bevacizumab) therapy further inhibited leukemia growth as compared with vehicle- or single-agent treated controls. However, concomitant administration of ASA404 with doxorubicin chemotherapy did not improve anti-leukemia effects and was in fact less effective than single agent therapy. In summary, our results demonstrate that ASA404 therapy is capable of mediating in vivo anti-tumor, anti-vascular and immunomodulatory effects in human acute leukemia models. Further strategies to modulate the marrow environment by combining a vascular disrupting agent with other biological agents for acute leukemia therapy may be warranted. However, given the time-dependent effects of VDAs such as ASA404 on tumor vascular function, combining VDAs with chemotherapy is likely to require further optimization of sequence and schedule of administration to ensure adequate marrow drug delivery and maximal therapeutic efficacy in hematological malignancy. Disclosures: No relevant conflicts of interest to declare.

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Hietschold, Volker, Nasreddin Abolmaali, and Thomas Kittner. "MRI of the coronary arteries: flip angle train optimization for 3D sequences." Zeitschrift für Medizinische Physik 12, no. 3 (2002): 177–81. http://dx.doi.org/10.1016/s0939-3889(15)70465-4.

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Salerno, Michael, Christopher T. Sica, Christopher M. Kramer, and Craig H. Meyer. "Optimization of spiral-based pulse sequences for first-pass myocardial perfusion imaging." Magnetic Resonance in Medicine 65, no. 6 (January 10, 2011): 1602–10. http://dx.doi.org/10.1002/mrm.22746.

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Toms, A. P., C. Smith-Bateman, P. N. Malcolm, J. Cahir, and M. Graves. "Optimization of metal artefact reduction (MAR) sequences for MRI of total hip prostheses." Clinical Radiology 65, no. 6 (June 2010): 447–52. http://dx.doi.org/10.1016/j.crad.2009.12.014.

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de Sousa, Paulo Loureiro, Alexandre Vignaud, Ericky Caldas de Almeida Araújo, and Pierre G. Carlier. "Factors controlling T 2 mapping from partially spoiled SSFP sequence: Optimization for skeletal muscle characterization." Magnetic Resonance in Medicine 67, no. 5 (August 16, 2011): 1379–90. http://dx.doi.org/10.1002/mrm.23131.

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Lee, Philip K., Lauren E. Watkins, Timothy I. Anderson, Guido Buonincontri, and Brian A. Hargreaves. "Flexible and efficient optimization of quantitative sequences using automatic differentiation of Bloch simulations." Magnetic Resonance in Medicine 82, no. 4 (May 26, 2019): 1438–51. http://dx.doi.org/10.1002/mrm.27832.

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Zarghami, Niloufar, Alexandre A. Khrapitchev, Francisco Perez-Balderas, Manuel Sarmiento Soto, James R. Larkin, Luca Bau, and Nicola R. Sibson. "Optimization of molecularly targeted MRI in the brain: empirical comparison of sequences and particles." International Journal of Nanomedicine Volume 13 (July 2018): 4345–59. http://dx.doi.org/10.2147/ijn.s158071.

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Fowler, Kathryn J., Jon McConathy, and Vamsi R. Narra. "Whole-body simultaneous positron emission tomography (PET)-MR: Optimization and adaptation of MRI sequences." Journal of Magnetic Resonance Imaging 39, no. 2 (October 29, 2013): 259–68. http://dx.doi.org/10.1002/jmri.24308.

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Dreher, Wolfgang, and Peter Börnert. "Pulse sequence and parameter choice in NMR imaging as a problem of constrained multidimensional nonlinear optimization." Magnetic Resonance in Medicine 8, no. 1 (September 1988): 16–24. http://dx.doi.org/10.1002/mrm.1910080103.

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