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Journal articles on the topic 'Echo planar imaging (EPI)'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Dudau, Cristina, Ashleigh Draper, Maria Gkagkanasiou, Geoffrey Charles-Edwards, Irumee Pai, and Steve Connor. "Cholesteatoma: multishot echo-planar vs non echo-planar diffusion-weighted MRI for the prediction of middle ear and mastoid cholesteatoma." BJR|Open 1, no. 1 (July 2019): 20180015. http://dx.doi.org/10.1259/bjro.20180015.

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Objective: We aimed to compare a newer readout-segmented echoplanar imaging (RS-EPI) technique with the established single shot turbo spin echo (SS-TSE) non-EPI diffusion-weighted imaging (DWI) in detecting surgically validated cholesteatoma. Methods: We retrospectively reviewed 358 consecutive MRI studies in 285 patients in which both RS-EPI and non-EPI DWI sequences were performed. Each diffusion sequence was reviewed independently and scored negative, indeterminate or positive for cholesteatoma in isolation and after reviewing the T1W sequence. Average artefacts scores were evaluated and the lesion size measured as a distortion indicator. The imaging scores were correlated with surgical validation, clinical and imaging follow-up. Results: There were 239 middle ear and central mastoid tract and 34 peripheral mastoid lesions. 102 tympanomastoid operations were performed. The positive predictive value ( PPV), post-operative PPV, primary PPV, negative predictive value were 93%, 95%, 87.5%, 70% for RS-EPI and 92.5%, 93.6%, 90%, 79% for non-EPI DWI. There was good agreement between the two techniques (k = 0.75). Non-EPI DWI is less susceptible to skull base artefacts although the mean cholesteatoma measurement difference was only 0.53 mm. Conclusion: RS-EPI has comparable PPV with non-EPI DWI in both primary and post-operative cholesteatoma but slightly lower negative predictive value. When there is a mismatch, non-EPI DWI better predicts the presence of cholesteatoma. There is good agreement between the sequences for cholesteatoma diagnosis. The T1W sequence is very important in downgrading indeterminate DWI signal lesions to a negative score. Advances in knowledge: This is, to our knowledge, the first study to compare a multishot EPI DWI technique with the established non- EPI DWI in cholesteatoma diagnosis.

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2

Shimada, Kouji, Yukio Kawashima, Kouji Wada, Yoshikazu Shibata, and Toshio Matoba. "Functional MRI using Echo planar Imaging." Japanese Journal of Radiological Technology 52, no. 9 (1996): 1179. http://dx.doi.org/10.6009/jjrt.kj00001354921.

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3

Xu, Xiaoquan, Yanjun Wang, Hao Hu, Guoyi Su, Hu Liu, Haibin Shi, and Feiyun Wu. "Readout-segmented echo-planar diffusion-weighted imaging in the assessment of orbital tumors: comparison with conventional single-shot echo-planar imaging in image quality and diagnostic performance." Acta Radiologica 58, no. 12 (March 22, 2017): 1457–67. http://dx.doi.org/10.1177/0284185117695667.

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Background Readout-segmented echo-planar imaging (RS-EPI) could improve the imaging quality of diffusion-weighted imaging (DWI) in various organs. However, whether it could improve the imaging quality and diagnostic performance for the patients with orbital tumors is still unknown. Purpose To compare the image quality and diagnostic performance of RS-EPI DWI with that of conventional single-shot EPI (SS-EPI) DWI in patients with orbital tumors. Material and Methods SS-EPI and RS-EPI DW images of 32 patients with pathologically diagnosed orbital tumors were retrospectively analyzed. Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR]) were assessed by two independent radiologists, and compared between SS-EPI and RS-EPI DWI. Receiver operating characteristic curves were used to determine the diagnostic value of ADC in differentiating malignant from benign orbital tumors. Results RS-EPI DW imaging produced less geometric distortion and ghosting artifacts, and better imaging sharpness and overall imaging quality than SS-EPI DWI (for all, P < 0.001). Meanwhile, RS-EPI DWI produced significantly lower SNR ( P < 0.001) and ADC ( P < 0.001), and higher contrast ( P < 0.001) than SS-EPI DWI, while producing no difference in CNR ( P = 0.137). There was no significant difference on the diagnostic performance between SS-EPI and RS-EPI DWI, when using ADC as the differentiating index ( P = 0.529). Conclusion Compared with SS-EPI, RS-EPI DWI provided significantly better imaging quality and comparable diagnostic performance in differentiating malignant from benign orbital tumors.

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4

Morelli, John N., Megan R. Saettele, Rajesh A. Rangaswamy, Lan Vu, Clint M. Gerdes, Wei Zhang, and Fei Ai. "Echo Planar Diffusion-Weighted Imaging: Possibilities and Considerations with 12- and 32-Channel Head Coils." Journal of Clinical Imaging Science 2 (May 23, 2012): 31. http://dx.doi.org/10.4103/2156-7514.96548.

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Interest in clinical brain magnetic resonance imaging using 32-channel head coils for signal reception continues to increase. The present investigation assesses possibilities for improving diffusion-weighted image quality using a 32-channel in comparison to a conventional 12-channel coil. The utility of single-shot (ss) and an approach to readout-segmented (rs) echo planar imaging (EPI) are examined using both head coils. Substantial image quality improvements are found with rs-EPI. Imaging with a 32-channel head coil allows for implementation of greater parallel imaging acceleration factors or acquisition of scans at a higher resolution. Specifically, higher resolution imaging with rs-EPI can be achieved by increasing the number of readout segments without increasing echo-spacing or echo time to the degree necessary with ss-EPI — a factor resulting in increased susceptibility artifact and reduced signal-to-noise with the latter.

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5

Poser, Benedikt A., Markus Barth, Pål-Erik Goa, Weiran Deng, and V. Andrew Stenger. "Single-shot echo-planar imaging with Nyquist ghost compensation: Interleaved dual echo with acceleration (IDEA) echo-planar imaging (EPI)." Magnetic Resonance in Medicine 69, no. 1 (March 12, 2012): 37–47. http://dx.doi.org/10.1002/mrm.24222.

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6

An, He, Xiaodong Ma, Ziyi Pan, Hua Guo, and Elaine Yuen Phin Lee. "Qualitative and quantitative comparison of image quality between single-shot echo-planar and interleaved multi-shot echo-planar diffusion-weighted imaging in female pelvis." European Radiology 30, no. 4 (December 10, 2019): 1876–84. http://dx.doi.org/10.1007/s00330-019-06491-3.

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Abstract Objectives To qualitatively and quantitatively compare the image quality between single-shot echo-planar (SS-EPI) and multi-shot echo-planar (IMS-EPI) diffusion-weighted imaging (DWI) in female pelvis Methods This was a prospective study involving 80 females who underwent 3.0T pelvic magnetic resonance imaging (MRI). SS-EPI and IMS-EPI DWI were acquired with 3 b values (0, 400, 800 s/mm2). Two independent reviewers assessed the overall image quality, artifacts, sharpness, and lesion conspicuity based on a 5-point Likert scale. Regions of interest (ROI) were placed on the endometrium and the gluteus muscles to quantify the signal intensities and apparent diffusion coefficient (ADC). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and geometric distortion were quantified on both sequences. Inter-rater agreement was assessed using κ statistics and Kendall test. Qualitative scores were compared using Wilcoxon signed-rank test and quantitative parameters were compared with paired t test and Bland-Altman analysis. Results IMS-EPI demonstrated better image quality than SS-EPI for all aspects evaluated (SS-EPI vs. IMS-EPI: overall quality 3.04 vs. 4.17, artifacts 3.09 vs. 3.99, sharpness 2.40 vs. 4.32, lesion conspicuity 3.20 vs. 4.25; p < 0.001). Good agreement and correlation were observed between two reviewers (SS-EPI κ 0.699, r 0.742; IMS-EPI κ 0.702, r 0.789). IMS-EPI showed lower geometric distortion, SNR, and CNR than SS-EPI (p < 0.050). There was no significant difference in the mean ADC between the two sequences. Conclusion IMS-EPI showed better image quality with lower geometric distortion without affecting the quantification of ADC, though the SNR and CNR decreased due to post-processing limitations. Key Points • IMS-EPI showed better image quality than SS-EPI. • IMS-EPI showed lower geometric distortion without affecting ADC compared with SS-EPI. • The SNR and CNR of IMS-EPI decreased due to post-processing limitations.

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7

Ordidge, R. "The development of echo-planar imaging (EPI): 1977–1982." Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine 9, no. 3 (December 1999): 117–21. http://dx.doi.org/10.1007/bf02594607.

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Ordidge, R. "The development of echo-planar imaging (EPI): 1977–1982." Magnetic Resonance Materials in Biology, Physics, and Medicine 9, no. 3 (December 1999): 117–21. http://dx.doi.org/10.1016/s1352-8661(99)00056-3.

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9

Yoshizako, Takeshi, Rika Yoshida, Hiroya Asou, Megumi Nakamura, and Hajime Kitagaki. "Comparison between turbo spin-echo and echo planar diffusion-weighted imaging of the female pelvis with 3T MRI." Acta Radiologica Open 10, no. 2 (February 2021): 205846012199473. http://dx.doi.org/10.1177/2058460121994737.

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Background Echo-planar imaging (EPI)-diffusion-weighted imaging (DWI) may take unclear image affected by susceptibility, geometric distortions and chemical shift artifacts. Purpose To compare the image quality and usefulness of EPI-DWI and turbo spin echo (TSE)-DWI in female patients who required imaging of the pelvis. Material and Methods All 57 patients were examined with a 3.0-T MR scanner. Both TSE- and EPI-DWI were performed with b values of 0 and 1000 s/mm2. We compared geometric distortion, the contrast ratio (CR) of the myometrium to the muscle and the apparent diffusion coefficient (ADC) values for the myometrium and lesion. Two radiologists scored the TSE- and EPI-DWI of each patient for qualitative evaluation. Results The mean percent distortion was significantly smaller with TSE- than EPI-DWI ( p = 0.00). The CR was significantly higher with TSE- than EPI-DWI ( p = 0.003). There was a significant difference in the ADC value for the uterus and lesions between the EPI- and TSE-DWI ( p < 0.05). Finally, the ADC values of cancer were significantly different from those for the uterus and benign with both the two sequences ( p < 0.05). The scores for ghosting artifacts were higher with TSE- than EPI-DWI ( p = 0.019). But there were no significant differences between TSE- and EPI-DWI with regard to image contrast and overall image quality. Conclusion TSE-DWI on the female pelvis by 3T MRI produces less distortion and higher CR than EPI-DWI, but there is no difference in contrast and image quality.

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10

Chen, Nan-kuei, Koichi Oshio, and Lawrence P. Panych. "Improved image reconstruction for partial fourier gradient-echo echo-planar imaging (EPI)." Magnetic Resonance in Medicine 59, no. 4 (2008): 916–24. http://dx.doi.org/10.1002/mrm.21529.

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11

Yeom, Kristen W., Matus Straka, Michael Iv, Michael E. Moseley, Patrick D. Barnes, Stefan Skare, and Samantha J. Holdsworth. "Intensity-Corrected Dual-Echo Echo-Planar Imaging (DE-EPI) for Improved Pediatric Brain Diffusion Imaging." PLOS ONE 10, no. 6 (June 12, 2015): e0129325. http://dx.doi.org/10.1371/journal.pone.0129325.

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12

Preibisch, Christine, Ulrich Pilatus, Jürgen Bunke, Frank Hoogenraad, Friedhelm Zanella, and Heinrich Lanfermann. "Functional MRI using sensitivity-encoded echo planar imaging (SENSE-EPI)." NeuroImage 19, no. 2 (June 2003): 412–21. http://dx.doi.org/10.1016/s1053-8119(03)00080-6.

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13

Stehling, M. K., R. J. Ordidge, R. Coxon, and P. Mansfield. "Inversion-recovery echo-planar imaging (ir-epi) at 0.5 T." Magnetic Resonance in Medicine 13, no. 3 (March 1990): 514–17. http://dx.doi.org/10.1002/mrm.1910130320.

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14

Blazey, Tyler, Galen D. Reed, Joel R. Garbow, and Cornelius von Morze. "Metabolite-Specific Echo-Planar Imaging of Hyperpolarized [1-13C]Pyruvate at 4.7 T." Tomography 7, no. 3 (September 15, 2021): 466–76. http://dx.doi.org/10.3390/tomography7030040.

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Although hyperpolarization (HP) greatly increases the sensitivity of 13C MR, the usefulness of HP in vivo is limited by the short lifetime of HP agents. To address this limitation, we developed an echo-planar (EPI) sequence with spectral-spatial radiofrequency (SSRF) pulses for fast and efficient metabolite-specific imaging of HP [1-13C]pyruvate and [1-13C]lactate at 4.7 T. The spatial and spectral selectivity of each SSRF pulse was verified using simulations and phantom testing. EPI and CSI imaging of the rat abdomen were compared in the same rat after injecting HP [1-13C]pyruvate. A procedure was also developed to automatically set the SSRF excitation pulse frequencies based on real-time scanner feedback. The most significant results of this study are the demonstration that a greater spatial and temporal resolution is attainable by metabolite-specific EPI as compared with CSI, and the enhanced lifetime of the HP signal in EPI, which is attributable to the independent flip angle control between metabolites. Real-time center frequency adjustment was also highly effective for minimizing off-resonance effects. To the best of our knowledge, this is the first demonstration of metabolite-specific HP 13C EPI at 4.7 T. In conclusion, metabolite-specific EPI using SSRF pulses is an effective way to image HP [1-13C]pyruvate and [1-13C]lactate at 4.7 T.

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Måsson, S., E. Johansson, J. Svensson, L. E. Olsson, F. Ståhlberg, J. S. Petersson, and K. Golman. "Echo-planar MR imaging of dissolved hyperpolarized 129Xe: Potential for MR angiography." Acta Radiologica 43, no. 5 (September 2002): 455–60. http://dx.doi.org/10.1258/rsmacta.43.5.455.

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Purpose: The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2≈20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe.

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Turner, Robert, Markus von Kienlin, Chrit T. W. Moonen, and Peter C. M. van Zijl. "Single-shot localized echo-planar imaging (STEAM-EPI) at 4.7 tesla." Magnetic Resonance in Medicine 14, no. 2 (May 1990): 401–8. http://dx.doi.org/10.1002/mrm.1910140225.

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17

Han, Paul Kyu, Sung-Hong Park, Seong-Gi Kim, and Jong Chul Ye. "Compressed Sensing for fMRI: Feasibility Study on the Acceleration of Non-EPI fMRI at 9.4T." BioMed Research International 2015 (2015): 1–24. http://dx.doi.org/10.1155/2015/131926.

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Conventional functional magnetic resonance imaging (fMRI) technique known as gradient-recalled echo (GRE) echo-planar imaging (EPI) is sensitive to image distortion and degradation caused by local magnetic field inhomogeneity at high magnetic fields. Non-EPI sequences such as spoiled gradient echo and balanced steady-state free precession (bSSFP) have been proposed as an alternative high-resolution fMRI technique; however, the temporal resolution of these sequences is lower than the typically used GRE-EPI fMRI. One potential approach to improve the temporal resolution is to use compressed sensing (CS). In this study, we tested the feasibility ofk-tFOCUSS—one of the high performance CS algorithms for dynamic MRI—for non-EPI fMRI at 9.4T using the model of rat somatosensory stimulation. To optimize the performance of CS reconstruction, different sampling patterns andk-tFOCUSS variations were investigated. Experimental results show that an optimizedk-tFOCUSS algorithm with acceleration by a factor of 4 works well for non-EPI fMRI at high field under various statistical criteria, which confirms that a combination of CS and a non-EPI sequence may be a good solution for high-resolution fMRI at high fields.

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Dragonu, Iulius, Baudouin Denis de Senneville, Bruno Quesson, Chrit Moonen, and Mario Ries. "Real-time geometric distortion correction for interventional imaging with echo-planar imaging (EPI)." Magnetic Resonance in Medicine 61, no. 4 (April 2009): 994–1000. http://dx.doi.org/10.1002/mrm.21903.

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19

Kim, Lily H., Edward H. Lee, Michelle Galvez, Murat Aksoy, Stefan Skare, Rafael O’Halloran, Michael S. B. Edwards, Samantha J. Holdsworth, and Kristen W. Yeom. "Reduced field of view echo-planar imaging diffusion tensor MRI for pediatric spinal tumors." Journal of Neurosurgery: Spine 31, no. 4 (October 2019): 607–15. http://dx.doi.org/10.3171/2019.4.spine19178.

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OBJECTIVESpine MRI is a diagnostic modality for evaluating pediatric CNS tumors. Applying diffusion-weighted MRI (DWI) or diffusion tensor imaging (DTI) to the spine poses challenges due to intrinsic spinal anatomy that exacerbates various image-related artifacts, such as signal dropouts or pileups, geometrical distortions, and incomplete fat suppression. The zonal oblique multislice (ZOOM)–echo-planar imaging (EPI) technique reduces geometric distortion and image blurring by reducing the field of view (FOV) without signal aliasing into the FOV. The authors hypothesized that the ZOOM-EPI method for spine DTI in concert with conventional spinal MRI is an efficient method for augmenting the evaluation of pediatric spinal tumors.METHODSThirty-eight consecutive patients (mean age 8 years) who underwent ZOOM-EPI spine DTI for CNS tumor workup were retrospectively identified. Patients underwent conventional spine MRI and ZOOM-EPI DTI spine MRI. Two blinded radiologists independently reviewed two sets of randomized images: conventional spine MRI without ZOOM-EPI DTI, and conventional spine MRI with ZOOM-EPI DTI. For both image sets, the reviewers scored the findings based on lesion conspicuity and diagnostic confidence using a 5-point Likert scale. The reviewers also recorded presence of tumors. Quantitative apparent diffusion coefficient (ADC) measurements of various spinal tumors were extracted. Tractography was performed in a subset of patients undergoing presurgical evaluation.RESULTSSixteen patients demonstrated spinal tumor lesions. The readers were in moderate agreement (kappa = 0.61, 95% CI 0.30–0.91). The mean scores for conventional MRI and combined conventional MRI and DTI were as follows, respectively: 3.0 and 4.0 for lesion conspicuity (p = 0.0039), and 2.8 and 3.9 for diagnostic confidence (p < 0.001). ZOOM-EPI DTI identified new lesions in 3 patients. In 3 patients, tractography used for neurosurgical planning showed characteristic fiber tract projections. The mean weighted ADCs of low- and high-grade tumors were 1201 × 10−6 and 865 × 10−6 mm2/sec (p = 0.002), respectively; the mean minimum weighted ADCs were 823 × 10−6 and 474 × 10−6 mm2/sec (p = 0.0003), respectively.CONCLUSIONSDiffusion MRI with ZOOM-EPI can improve the detection of spinal lesions while providing quantitative diffusion information that helps distinguish low- from high-grade tumors. By adding a 2-minute DTI scan, quantitative diffusion information and tract profiles can reliably be obtained and serve as a useful adjunct to presurgical planning for pediatric spinal tumors.

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Lei, Qiang, Qi Wan, Lishan Liu, Jianfeng Hu, Wei Zuo, Jianneng Li, Guihua Jiang, and Xinchun Li. "Values of Apparent Diffusion Coefficient and Lesion-to-Spinal Cord Signal Intensity in Diagnosing Solitary Pulmonary Lesions: Turbo Spin-Echo versus Echo-Planar Imaging Diffusion-Weighted Imaging." BioMed Research International 2021 (August 10, 2021): 1–8. http://dx.doi.org/10.1155/2021/3345953.

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Objective. This study is aimed at comparing the image quality and diagnostic performance of mean apparent diffusion coefficient (ADC) and lesion-to-spinal cord signal intensity ratio (LSR) derived from turbo spin-echo diffusion-weighted imaging (TSE-DWI) and echo-planar imaging- (EPI-) DWI in patients with a solitary pulmonary lesion (SPL). Methods. 33 patients with SPL underwent chest imaging using EPI-DWI and TSE-DWI with b = 600 s/mm2 in free breathing. A comparison of the distortion ratio (DR), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) was drawn between the two techniques using a Wilcoxon signed-rank test. The interprotocol reproducibility between quantitative parameters of EPI-DWI and TSE-DWI was evaluated using a Bland-Altman plot. ADCs and LSRs derived from EPI-DWI and TSE-DWI were calculated and compared between malignant and benign groups using the Mann–Whitney test. Results. TSE-DWI had similar SNR and CNR compared with EPI-DWI. DR was significantly lower on TSE-DWI than EPI-DWI. ADC and LSR showed slightly higher values with TSE-DWI, while the Bland-Altman analysis showed unacceptable limits of agreement between the two sequences. ADC and LSR of both DWI techniques differed significantly between lung cancer and benign lesions ( P < 0.05 ). The LSR(EPI-DWI) showed the highest area under the curve ( AUC = 0.818 ), followed by ADC(EPI-DWI) ( AUC = 0.789 ), ADC(TSE-DWI) ( AUC = 0.781 ), and LSR(TSE-DWI) ( AUC = 0.748 ), respectively. Among these parameters, the difference in diagnostic accuracy was not statistically significant. Conclusions. TSE-DWI provides significantly improved image quality in patients with SPL as compared with EPI-DWI. However, there was no difference in diagnostic efficacy between these two techniques, according to ADC and LSR.

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Kang, Daehun, Yul-Wan Sung, and Chang-Ki Kang. "Fast Imaging Technique for fMRI: Consecutive Multishot Echo Planar Imaging Accelerated with GRAPPA Technique." BioMed Research International 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/394213.

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This study was to evaluate the proposed consecutive multishot echo planar imaging (cmsEPI) combined with a parallel imaging technique in terms of signal-to-noise ratio (SNR) and acceleration for a functional imaging study. We developed cmsEPI sequence using both consecutively acquired multishot EPI segments and variable flip angles to minimize the delay between segments and to maximize the SNR, respectively. We also combined cmsEPI with the generalized autocalibrating partially parallel acquisitions (GRAPPA) method. Temporal SNRs were measured at different acceleration factors and number of segments for functional sensitivity evaluation. We also examined the geometric distortions, which inherently occurred in EPI sequence. The practical acceleration factors,R=2orR=3, of the proposed technique improved the temporal SNR by maximally 18% in phantom test and by averagely 8.2% in in vivo experiment, compared to cmsEPI without parallel imaging. The data collection time was decreased in inverse proportion to the acceleration factor as well. The improved temporal SNR resulted in better statistical power when evaluated on the functional response of the brain. In this study, we demonstrated that the combination of cmsEPI with the parallel imaging technique could provide the improved functional sensitivity for functional imaging study, compensating for the lower SNR by cmsEPI.

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Amano, T., K. Tsuchiya, M. Kurita, S. Ooshimoda, Y. Kusakabe, and K. Ito. "Optimization of multi shot Echo Planar Imaging of the abdomen." Japanese Journal of Radiological Technology 53, no. 1 (1997): 190. http://dx.doi.org/10.6009/jjrt.kj00001355185.

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KOMIYA, TAIZO. "Study of Imaging Parameters for Three-dimensional Functional MRI Using Echo Planar Imaging." Japanese Journal of Radiological Technology 54, no. 1 (1998): 7–11. http://dx.doi.org/10.6009/jjrt.kj00001351680.

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Miyakawa, Kouzou, Takashi Asakura, Toshio Watanabe, Kiyotaka Nakajima, Kouki Oumi, Masakatsu Shimizu, and Yoshikazu Ikezaki. "454 Echo Planar Imaging on 0.5T MRI : A preliminary study." Japanese Journal of Radiological Technology 53, no. 8 (1997): 1323. http://dx.doi.org/10.6009/jjrt.kj00001356295.

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Biagini, Cristiano, Martina De Michele, Andrea Pratesi, Francesco Mungai, Margherita Betti, Giana Izzo, Carlo Biagini, and Luigi Natale. "Signal-to-Noise Ratio importance in Apparent Diffusion Coefficient measurements using Diffusion-Weighted Echo-Planar-Imaging scans." JOURNAL OF ADVANCES IN PHYSICS 4, no. 2 (April 22, 2014): 517–25. http://dx.doi.org/10.24297/jap.v4i2.2034.

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Purpose: To define experimental grounds for Apparent Diffusion Coefficient (ADC) measurements using Spin-Echo Diffusion-Weighted Echo-Planar (SE-DW-EPI) sequences, as a function of Signal-to-Noise Ratio (SNR).Methods: multiple multi-b SE-DW-EPI scans with the same parameters but the lipid suppression technique have been compared on water phantom with a 3T MRI equipment. The SNR has been estimated using the method of difference. Images have been analyzed manually, comparing the signal intensities at different b-values.Results: All measurements show a high repeatability and strong self-consistency. A significant dependence of the ADC on SNR has been shown, and its lowest limitto obtain reliable quantitative answers has been stated.Conclusion: ADC measurements in vivo must be carefully designed to avoid systematic errors during acquisition and post-processing due to low SNR.

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Takeo, Kazuhiro, Satoru Kohno, and Koji Shimizu. "Echo Planar Imaging on Clinical MR Scanner : Application to FMRI." Japanese Journal of Radiological Technology 52, no. 9 (1996): 1177. http://dx.doi.org/10.6009/jjrt.kj00001354919.

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Peng, Shuyi, Yihao Guo, Xiaoyong Zhang, Juan Tao, Jie Liu, Wenying Zhu, Leqing Chen, and Fan Yang. "High-Resolution DWI with Simultaneous Multi-Slice Readout-Segmented Echo Planar Imaging for the Evaluation of Malignant and Benign Breast Lesions." Diagnostics 11, no. 12 (December 4, 2021): 2273. http://dx.doi.org/10.3390/diagnostics11122273.

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To investigate the feasibility and effectiveness of high-resolution readout-segmented echo planar imaging (rs-EPI), diffusion-weighted imaging (DWI) is used simultaneously with multi-slice (SMS) imaging (SMS rs-EPI) for the differentiation of breast malignant and benign lesions in comparison to conventional rs-EPI on a 3T MR scanner. A total of 102 patients with 113 breast lesions underwent bilateral breast MRI using a prototype SMS rs-EPI sequence and a conventional rs-EPI sequence. Subjective image quality was assessed using a 5-point Likert scale (1 = poor, 5 = excellent). Signal-to-noise ratio (SNR), lesion contrast-to-noise ratio (CNR) and apparent diffusion coefficients (ADC) value of the lesion were measured for comparison. Receiver operating characteristic curve analysis was performed to evaluate the diagnosis performance of ADC, and the corresponding area under curve (AUC) was calculated. The image quality scores in anatomic distortion, lesion conspicuity, sharpness of anatomical details and overall image quality of SMS rs-EPI were significantly higher than those of conventional rs-EPI. CNR was enhanced in the high-resolution SMS rs-EPI acquisition (6.48 ± 1.71 vs. 4.23 ± 1.49; p < 0.001). The mean ADC value was comparable in SMS rs-EPI and conventional rs-EPI (benign 1.45 × 10−3 vs. 1.43 × 10−3 mm2/s, p = 0.702; malignant 0.91 × 10−3 vs. 0.89 × 10−3 mm2/s, p = 0.076). The AUC was 0.957 in SMS rs-EPI and 0.983 in conventional rs-EPI. SMS rs-EPI technique allows for higher spatial resolution and slight reduction of scan time in comparison to conventional rs-EPI, which has potential for better differentiation between malignant and benign lesions of the breast.

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Kao, Yi-Hsuan, Xin Wan, and James R. MacFall. "Simultaneous multislice acquisition with arterial-flow tagging (SMART) using echo planar imaging (EPI)." Magnetic Resonance in Medicine 39, no. 4 (April 1998): 662–65. http://dx.doi.org/10.1002/mrm.1910390422.

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Gräfe, Daniel, Anne Päts, Andreas Merkenschlager, Christian Roth, Franz Wolfgang Hirsch, Jens Frahm, and Dirk Voit. "STEAM-DWI as a robust alternative to EPI-DWI: Evaluation in pediatric brain MRI." PLOS ONE 17, no. 5 (May 18, 2022): e0268523. http://dx.doi.org/10.1371/journal.pone.0268523.

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Purpose Diffusion-weighted imaging (DWI) is an essential element of almost every brain MRI examination. The most widely applied DWI technique, a single-shot echo-planar imaging DWI (EPI-DWI) sequence, suffers from a high sensitivity to magnetic field inhomogeneities. As an alternative, a single-shot stimulated echo acquisition mode diffusion-weighted MRI (STEAM-DWI) has recently been re-introduced after it became significantly faster. The aim of the study was to investigate the applicability of STEAM-DWI as a substitute to EPI-DWI in a daily routine of pediatric radiology. Methods Retrospectively, brain MRI examinations of 208 children with both EPI-DWI and STEAM-DWI were assessed. Visual resolution and diagnostic confidence were evaluated, the extent of susceptibility artifacts was quantified, and contrast-to-noise ratio was calculated in case of diffusion restriction. Furthermore, the correlation of apparent diffusion coefficient values between STEAM-DWI and EPI-DWI was tested. Results STEAM-DWI was inferior to EPI-DWI in visual resolution but with higher diagnostic confidence and lower artifact size. The apparent diffusion coefficient values of both sequences demonstrated excellent correlation. The contrast-to-noise ratio of STEAM-DWI was only half of that of EPI-DWI (58% resp. 112%). Conclusion STEAM-DWI is a robust alternative to EPI-DWI when increased susceptibility artifacts are to be expected. Drawbacks are a lower contrast-to-noise ratio and poorer visual resolution.

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Tokoro, Hirokazu, Yasunari Fujinaga, Ayumi Ohya, Kazuhiko Ueda, Aya Shiobara, Yoshihiro Kitou, Hitoshi Ueda, and Masumi Kadoya. "Usefulness of free-breathing readout-segmented echo-planar imaging (RESOLVE) for detection of malignant liver tumors: Comparison with single-shot echo-planar imaging (SS-EPI)." European Journal of Radiology 83, no. 10 (October 2014): 1728–33. http://dx.doi.org/10.1016/j.ejrad.2014.06.013.

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Elefante, A., M. Cavaliere, C. Russo, G. Caliendo, M. Marseglia, D. Cicala, D. Piccolo, et al. "Diffusion Weighted MR Imaging of Primary and Recurrent Middle Ear Cholesteatoma: An Assessment by Readers with Different Expertise." BioMed Research International 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/597896.

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Introduction and Purpose. Diffusion weighted imaging (DWI) has been proven to be valuable in the diagnosis of middle ear cholesteatoma. The aims of our study were to evaluate the advantage of multi-shot turbo spin echo (MSh TSE) DWI compared to single-shot echo-planar (SSh EPI) DWI for the diagnosis of cholesteatoma.Material and Methods. Thirty-two patients with clinical suspicion of unilateral cholesteatoma underwent preoperative MRI (1.5T) with SSh EPI and MSh TSE. Images were separately analyzed by 4 readers with different expertise to confirm the presence of cholesteatoma. Sensitivity, specificity, diagnostic accuracy, and positive (PPV) and negative predictive values (NPV) were assessed for each observer and interrater agreement was assessed using kappa statistics. Diagnosis was obtained at surgery.Results. Overall MSh TSE showed higher diagnostic accuracy and lower negative predictive value (NPV) compared to conventional SSh EPI. Interreader agreement between the observers revealed the superiority of MSh TSE compared to SSh EPI. Interrater agreement among all the four observers was higher by using MSh TSE compared to SSh EPI.Conclusion. Our findings suggest that MSh TSE DWI has higher sensitivity for detection of cholesteatoma and lower probability of misdiagnosis. MSh TSE DWI is useful in guiding less experienced observers to the diagnosis.

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Seeger, Achim, Maximilian Schulze, Frank Schuettauf, Ulrike Ernemann, and Till-Karsten Hauser. "Advanced diffusion-weighted imaging in patients with optic neuritis deficit – value of reduced field of view DWI and readout-segmented DWI." Neuroradiology Journal 31, no. 2 (February 8, 2018): 126–32. http://dx.doi.org/10.1177/1971400918757711.

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Objective The objective of this article is to evaluate advanced techniques of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) measurements of the optic nerve in patients with optic neuritis. Methods In this prospective and institutional review board-approved trial, we examined 15 patients with acute visual loss and clinical signs of optic neuritis including thin-slice multi-shot segmented readout of long variable echo trains (rs-EPI, RESOLVE) DWI and reduced field-of view DWI using a parallel transmit system (rFOV-EPI). Conventional single-shot echo-planar DWI (ss-EPI) of the whole brain was available in 13 patients. Subjective image quality was compared using a four-point scale and objective ADC measurements were performed in comparison with the non-affected side. Results In the intraorbital segment, subjective image quality was significantly higher in rFOV-EPI (score 3.3 ± 0.8) compared with rs-EPI (score 2.1 ± 0.8) and ss-EPI (score 0.9 ± 0.8). Diagnosis was hampered in the canalicular segment ( n = 3) and the intracranial segment ( n = 1) in all applied DWI techniques. ADC measurements of the affected side differed significantly in all DWI sequences ss-EPI (sensitivity 54%, accuracy 77%), rs-EPI (sensitivity 71%, accuracy 86%), and rFOV-EPI (sensitivity 73%, accuracy 87%). Conclusion Optic neuritis in the intraorbital segment can be detected with high sensitivity without the need for contrast application. Using rFOV-EPI improves subjective image quality compared with rs-EPI and ss-EPI. Due to its higher spatial resolution, rFOV-EPI was the preferred technique in our study and can ensure the diagnosis in the intraorbital segment. However, artefacts occur in the canalicular and intracranial segment of the optic nerve, therefore contrast-enhanced T1-weighted images must still be considered as the gold standard.

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Trattnig, S., M. Breitenseher, G. Kontaxis, T. Helbich, T. Rand, and H. Imhof. "Grase: Ultra-fast turbo gradient spin-echo sequence." Acta Radiologica 38, no. 5 (September 1997): 880–84. http://dx.doi.org/10.1080/02841859709172429.

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Purpose: Ultra-fast gradient and spin-echo (GRASE) imaging is a hybrid of turbo spin-echo (TSE) and echo-planar imaging (EPI). One scan consists of several spinechoes (SEs) (turbo factor, TF), each of which consists of a number of gradient echoes (EPI factor, EF). The aim of our study was to evaluate different combinations of TF and EF in GRASE imaging and to test its usefulness in musculoskeletal imaging. Material and Methods: On a 1.0 T MR unit, 11 GRASE sequences with different combinations of TF and EF (TR/TE 2150/120 ms) were evaluated in phantom studies with respect to signal-to-noise (S/N) ratio, nonuniformity of images, and geometrical distortion. From this study, the optimal GRASE-sequence was applied to 25 patients with different joint pathologies and compared to a T2-weighted TSE sequence (TR/TE 2855/130 ms). Lesion visualization, conspicuity, overall image quality, and artifacts were qualitatively analyzed by two observers independently of each other. Results: With respect to S/N ratio, signal nonuniformity, and geometrical distortion, the GRASE sequence with TF/EF 7/3 (S/N 47; signal nonuniformity 11.7%; distortion 1 pixel) proved to be superior to the other GRASE sequences within a scanning time of less than 120s. In a clinical study, the GRASE sequence proved superior to T2-weighted TSE (without fat suppression) in the visualization of bone-marrow and soft-tissue lesions ( p < 0.001) and ligamentous injuries, although the image quality was inferior.

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De Landro, Martina, Jacopo Ianniello, Maxime Yon, Alexey Wolf, Bruno Quesson, Emiliano Schena, and Paola Saccomandi. "Fiber Bragg Grating Sensors for Performance Evaluation of Fast Magnetic Resonance Thermometry on Synthetic Phantom." Sensors 20, no. 22 (November 12, 2020): 6468. http://dx.doi.org/10.3390/s20226468.

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The increasing recognition of minimally invasive thermal treatment of tumors motivate the development of accurate thermometry approaches for guaranteeing the therapeutic efficacy and safety. Magnetic Resonance Thermometry Imaging (MRTI) is nowadays considered the gold-standard in thermometry for tumor thermal therapy, and assessment of its performances is required for clinical applications. This study evaluates the accuracy of fast MRTI on a synthetic phantom, using dense ultra-short Fiber Bragg Grating (FBG) array, as a reference. Fast MRTI is achieved with a multi-slice gradient-echo echo-planar imaging (GRE-EPI) sequence, allowing monitoring the temperature increase induced with a 980 nm laser source. The temperature distributions measured with 1 mm-spatial resolution with both FBGs and MRTI were compared. The root mean squared error (RMSE) value obtained by comparing temperature profiles showed a maximum error of 1.2 °C. The Bland-Altman analysis revealed a mean of difference of 0.1 °C and limits of agreement 1.5/−1.3 °C. FBG sensors allowed to extensively assess the performances of the GRE-EPI sequence, in addition to the information on the MRTI precision estimated by considering the signal-to-noise ratio of the images (0.4 °C). Overall, the results obtained for the GRE-EPI fully satisfy the accuracy (~2 °C) required for proper temperature monitoring during thermal therapies.

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T.M, Sreenivasa Murthy, Anita Nagadi, and Sneha Krishna Mohan. "Utility of Non-EPI DWI MRI in the Management of Pediatric Cholesteatoma." Annals of Otology and Neurotology 02, no. 01 (January 29, 2019): 43–45. http://dx.doi.org/10.1055/s-0039-1678467.

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Abstract Introduction Cholesteatoma in children can be acquired or congenital and is generally extensive. The most commonly used technique for the removal of cholesteatoma is intact canal wall mastoidectomy. This invariably leads to second-look surgery to assess for recurrence or residual cholesteatoma. Magnetic resonance imaging (MRI) with non–echo-planar imaging (non-EPI) diffusion-weighted imaging (DWI) is an accurate noninvasive imaging option that can be used in diagnosing primary cholesteatoma. This can also be used to diagnose residual or recurrent cholesteatoma in patients who have undergone intact canal wall mastoidectomy. Case Report A 7-year-old male patient presented with a 1-week history of foul-smelling discharge from the right ear. On examination, a polypoidal mass with keratinized debris was seen. A diagnosis of cholesteatoma of right ear was made. Imaging with high-resolution computed tomography (HRCT) of the temporal bone and non-EPI DWI MRI confirmed the same. The child underwent an intact canal wall mastoidectomy and was followed up at 2 years with non-EPI DWI MRI to monitor any residual or recurrent cholesteatoma. Conclusion Non-EPI DWI MRI provides a convenient, accurate, and noninvasive method of evaluating and monitoring for residual or recurrent cholesteatoma and thus helps avoid unnecessary second-look surgery.

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Hykin, J., P. Gowland, P. Baker, I. Johnson, and P. Mansfield. "Assessment of Fetal Growth and Estimation of Birthweight Using Echo-Planar Magnetic Resonance Imaging (EPI)." Clinical Science 86, s30 (February 1, 1994): 11P. http://dx.doi.org/10.1042/cs086011pa.

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Reber, Paul J., Eric C. Wong, Richard B. Buxton, and Lawrence R. Frank. "Correction of off resonance-related distortion in echo-planar imaging using EPI-based field maps." Magnetic Resonance in Medicine 39, no. 2 (February 1998): 328–30. http://dx.doi.org/10.1002/mrm.1910390223.

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Brüning, R., K. Seelos, T. Yousry, J. Scheidler, H. Exner, U. Porn, M. Reiser, and B. R. Rosen. "Echo-planar magnetic resonance imaging (EPI) with high-resolution matrix in intra-axial brain tumors." European Radiology 9, no. 7 (August 23, 1999): 1392–96. http://dx.doi.org/10.1007/s003300050854.

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Bammer, Roland, Stephen L. Keeling, Michael Augustin, Klaas P. Pruessmann, Roswitha Wolf, Rudolf Stollberger, Hans-Peter Hartung, and Franz Fazekas. "Improved diffusion-weighted single-shot echo-planar imaging (EPI) in stroke using sensitivity encoding (SENSE)." Magnetic Resonance in Medicine 46, no. 3 (2001): 548–54. http://dx.doi.org/10.1002/mrm.1226.

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Yeom, Kristen W., Samantha J. Holdsworth, Anh T. Van, Michael Iv, Stefan Skare, Robert M. Lober, and Roland Bammer. "Comparison of Readout-Segmented Echo-Planar Imaging (EPI) and Single-Shot EPI in Clinical Application of Diffusion-Weighted Imaging of the Pediatric Brain." American Journal of Roentgenology 200, no. 5 (May 2013): W437—W443. http://dx.doi.org/10.2214/ajr.12.9854.

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TSUCHIHASHI, TOSHIO, KENICHI TOMISATO, TOSHIO MAKI, ISAO FUJITA, and TAKESHI SUZUKI. "Evaluation of Fluid Attenuated Inversion Recovery (FLAIR) Using Echo Planar Imaging : With Reference to the Null Point." Japanese Journal of Radiological Technology 54, no. 4 (1998): 499–504. http://dx.doi.org/10.6009/jjrt.kj00001351982.

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Duong, Soan T. M., Son Lam Phung, Abdesselam Bouzerdoum, Sui Paul Ang, and Mark M. Schira. "Correcting Susceptibility Artifacts of MRI Sensors in Brain Scanning: A 3D Anatomy-Guided Deep Learning Approach." Sensors 21, no. 7 (March 26, 2021): 2314. http://dx.doi.org/10.3390/s21072314.

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Echo planar imaging (EPI), a fast magnetic resonance imaging technique, is a powerful tool in functional neuroimaging studies. However, susceptibility artifacts, which cause misinterpretations of brain functions, are unavoidable distortions in EPI. This paper proposes an end-to-end deep learning framework, named TS-Net, for susceptibility artifact correction (SAC) in a pair of 3D EPI images with reversed phase-encoding directions. The proposed TS-Net comprises a deep convolutional network to predict a displacement field in three dimensions to overcome the limitation of existing methods, which only estimate the displacement field along the dominant-distortion direction. In the training phase, anatomical T1-weighted images are leveraged to regularize the correction, but they are not required during the inference phase to make TS-Net more flexible for general use. The experimental results show that TS-Net achieves favorable accuracy and speed trade-off when compared with the state-of-the-art SAC methods, i.e., TOPUP, TISAC, and S-Net. The fast inference speed (less than a second) of TS-Net makes real-time SAC during EPI image acquisition feasible and accelerates the medical image-processing pipelines.

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Hong, Jia-Sheng, Ingo Hermann, Frank Gerrit Zöllner, Lothar R. Schad, Shuu-Jiun Wang, Wei-Kai Lee, Yung-Lin Chen, Yu Chang, and Yu-Te Wu. "Acceleration of Magnetic Resonance Fingerprinting Reconstruction Using Denoising and Self-Attention Pyramidal Convolutional Neural Network." Sensors 22, no. 3 (February 7, 2022): 1260. http://dx.doi.org/10.3390/s22031260.

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Magnetic resonance fingerprinting (MRF) based on echo-planar imaging (EPI) enables whole-brain imaging to rapidly obtain T1 and T2* relaxation time maps. Reconstructing parametric maps from the MRF scanned baselines by the inner-product method is computationally expensive. We aimed to accelerate the reconstruction of parametric maps for MRF-EPI by using a deep learning model. The proposed approach uses a two-stage model that first eliminates noise and then regresses the parametric maps. Parametric maps obtained by dictionary matching were used as a reference and compared with the prediction results of the two-stage model. MRF-EPI scans were collected from 32 subjects. The signal-to-noise ratio increased significantly after the noise removal by the denoising model. For prediction with scans in the testing dataset, the mean absolute percentage errors between the standard and the final two-stage model were 3.1%, 3.2%, and 1.9% for T1, and 2.6%, 2.3%, and 2.8% for T2* in gray matter, white matter, and lesion locations, respectively. Our proposed two-stage deep learning model can effectively remove noise and accurately reconstruct MRF-EPI parametric maps, increasing the speed of reconstruction and reducing the storage space required by dictionaries.

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YAMADA, Masayuki, Masato NAKANE, Tatsuhiko OKADA, Yoshifumi KUWAYAMA, Hirofumi ANNO, and Kazuhiro KATADA. "Diffusion-weighted Single Shot Fast Spin Echo Imaging for Patients with Metallic Dental Materials : Comparison with Diffusion-weighted Echo Planar Imaging." Japanese Journal of Radiological Technology 56, no. 10 (2000): 1266–68. http://dx.doi.org/10.6009/jjrt.kj00001357330.

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Ramb, Rebecca, Irina Mader, Bernd Jung, Jürgen Hennig, and Maxim Zaitsev. "High resolution CBV assessment with PEAK-EPI: k-t-undersampling and reconstruction in echo planar imaging." Magnetic Resonance in Medicine 77, no. 6 (June 25, 2016): 2153–66. http://dx.doi.org/10.1002/mrm.26298.

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Cacace, Anthony T., Talin Tasciyan, and Joseph P. Cousins. "Principles of Functional Magnetic Resonance Imaging: Application to Auditory Neuroscience." Journal of the American Academy of Audiology 11, no. 05 (May 2000): 239–72. http://dx.doi.org/10.1055/s-0042-1748052.

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AbstractFunctional imaging based on magnetic resonance methods is a new research frontier for exploring a wide range of central nervous system (CNS) functions, including information processing in sensory, motor, cognitive, and linguistic systems. Being able to localize and study human brain function in vivo, in relatively high resolution and in a noninvasive manner, makes this a technique of unparalleled importance. In order to appreciate and fully understand this area of investigation, a tutorial covering basic aspects of this methodology is presented. We introduce functional magnetic resonance imaging (fMRI) by providing an overview of the studies of different sensory systems in response to modality-specific stimuli, followed by an outline of other areas that have potential clinical relevance to the medical, cognitive, and communicative sciences. The discussion then focuses on the basic principles of magnetic resonance methods including magnetic resonance imaging, MR spectroscopy, fMRI, and the potential role that MR technology may play in understanding a wide range of auditory functions within the CNS, including tinnitus-related activity. Because the content of the material found herein might be unfamiliar to some, we provide a broad range of background and review articles to serve as a technical resource. Abbreviations: AL = anterior lateral, BOLD = blood oxygen level dependent, Cho = choline, CL = caudal lateral, CNS = central nervous system, CR = creatine, EEG = electroencephalography, EPI = echo planar imaging, ER = event related, ETS = echo-time shifting, fMRI = functional magnetic resonance imaging, FOV = field of view, G = Gauss, GET = gaze-evoked tinnitus, GRE = gradient-recalled echo, MEG = magnetoencephalography, ml = myo-inositol, ML = medial lateral, MRI = magnetic resonance imaging, MRS = magnetic resonance spectroscopy, NAA = N-acetylaspartate, NMR = nuclear magnetic resonance, PET = positron emission tomography, PRESTO = principles of echo shifting with a train of observations, RF = radio frequency, ROI = regions of interest, SE = spin echo, STEAM = short-TE stimulated echo acquisition mode, Τ = Tesla, TE = echo time, TR = repetition time

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Schwickert, Heidi C., Timothy P. L. Roberts, David M. Shames, Cornelis F. Van Dijke, Alexander Disston, Andreas Mühler, Jeffry S. Mann, and Robert C. Brasch. "Quantification of liver blood volume: comparison of ultra short ti inversion recovery echo planar imaging (ulstir-epi), with dynamic 3d-gradient recalled echo imaging." Magnetic Resonance in Medicine 34, no. 6 (December 1995): 845–52. http://dx.doi.org/10.1002/mrm.1910340609.

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Sati, P., DM Thomasson, N. Li, DL Pham, NM Biassou, DS Reich, and JA Butman. "Rapid, high-resolution, whole-brain, susceptibility-based MRI of multiple sclerosis." Multiple Sclerosis Journal 20, no. 11 (March 17, 2014): 1464–70. http://dx.doi.org/10.1177/1352458514525868.

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Background: Susceptibility-based MRI offers a unique opportunity to study neurological diseases such as multiple sclerosis (MS). In this work, we assessed a three-dimensional segmented echo-planar-imaging (3D-EPI) sequence to rapidly acquire high-resolution T2*-weighted and phase contrast images of the whole brain. We also assessed if these images could depict important features of MS at clinical field strength, and we tested the effect of a gadolinium-based contrast agent (GBCA) on these images. Materials and methods: The 3D-EPI acquisition was performed on four healthy volunteers and 15 MS cases on a 3T scanner. The 3D sagittal images of the whole brain were acquired with a voxel size of 0.55 × 0.55 × 0.55 mm3 in less than 4 minutes. For the MS cases, the 3D-EPI acquisition was performed before, during, and after intravenous GBCA injection. Results: Both T2*-weighted and phase-contrast images from the 3D-EPI acquisition were sensitive to the presence of lesions, parenchymal veins, and tissue iron. Conspicuity of the veins was enhanced when images were obtained during injection of GBCA. Conclusions: We propose this rapid imaging sequence for investigating, in a clinical setting, the spatiotemporal relationship between small parenchymal veins, iron deposition, and lesions in MS patient brains.

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Park, Jin Young, Hee Jung Shin, Ki Chang Shin, Yu Sub Sung, Woo Jung Choi, Eun Young Chae, Joo Hee Cha, and Hak Hee Kim. "Comparison of readout segmented echo planar imaging (EPI) and EPI with reduced field-of-VIew diffusion-weighted imaging at 3t in patients with breast cancer." Journal of Magnetic Resonance Imaging 42, no. 6 (May 6, 2015): 1679–88. http://dx.doi.org/10.1002/jmri.24940.

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Kasprian, Gregor J., Michael J. Paldino, Amy R. Mehollin-Ray, Anil Shetty, Jennifer L. Williams, Wesley Lee, and Chris I. Cassady. "Prenatal Imaging of Occipital Encephaloceles." Fetal Diagnosis and Therapy 37, no. 3 (October 29, 2014): 241–48. http://dx.doi.org/10.1159/000366159.

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Introduction: This retrospective study aims to describe systematically the fetal cerebral MR morphology in cases with occipital meningoencephaloceles using standard and advanced fetal MRI techniques. Material and Methods: The 1.5-tesla MR examinations (T1- and T2-weighted imaging, echo planar imaging, EPI, diffusion-weighted imaging, DWI) of 14 fetuses with occipital/parietal meningoencephaloceles were retrospectively analyzed for the classification of anatomic characteristics. A diffusion tensor sequence was performed in 5 cases. Results: In 9/14 cases the occipital lobes were entirely or partially included in the encephalocele sac. Typical features of Chiari III malformation were seen in 6/14 cases. The displaced brain appeared grossly disorganized in 6/14. The brainstem displayed abnormal ‘kinking'/rotation (3/14), a z-shape (1/14) and/or a molar tooth-like configuration of the midbrain (3/14). Tractography revealed the presence and position of sensorimotor tracts in 5/5 and the corpus callosum in 3/5. DWI was helpful in the identification of a displaced brain (in 8/9). EPI visualized the anatomy of draining cerebral veins in 7/9 cases. Clinical (9/14) and MRI (7/14) follow-up data are presented. Discussion: Encephaloceles show a wide range of morphological heterogeneity. Fetal MRI serves as an accurate tool in the visualization of brainstem, white matter pathway and cerebral venous involvement and facilitates the detection of specific underlying syndromes such as ciliopathies.

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