New Imaging Strategies Using a Motion-Resistant Liver Sequence in Uncooperative Patients

MR imaging has unique benefits for evaluating the liver because of its high-resolution capability and ability to permit detailed assessment of anatomic lesions. In uncooperative patients, motion artifacts can impair the image quality and lead to the loss of diagnostic information. In this setting, the recent advances in motion-resistant liver MR techniques, including faster imaging protocols (e.g., dual-echo magnetization-prepared rapid-acquisition gradient echo (MP-RAGE), view-sharing technique), the data under-sampling (e.g., gradient recalled echo (GRE) with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), single-shot echo-train spin-echo (SS-ETSE)), and motion-artifact minimization method (e.g., radial GRE with/without k-space-weighted image contrast (KWIC)), can provide consistent, artifact-free images with adequate image quality and can lead to promising diagnostic performance. Understanding of the different motion-resistant options allows radiologists to adopt the most appropriate technique for their clinical practice and thereby significantly improve patient care.

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Image quality assessment of single-shot turbo spin echo diffusion-weighted imaging with parallel imaging technique: a phantom study

British Journal of Radiology ◽

10.1259/bjr.20160512 ◽

2016 ◽

Vol 89 (1065) ◽

pp. 20160512 ◽

Cited By ~ 12

Author(s):

Tsukasa Yoshida ◽

Atsushi Urikura ◽

Kensei Shirata ◽

Yoshihiro Nakaya ◽

Shingo Terashima ◽

...

Keyword(s):

Image Quality ◽

Quality Assessment ◽

Diffusion Weighted Imaging ◽

Parallel Imaging ◽

Image Quality Assessment ◽

Imaging Technique ◽

Spin Echo ◽

Single Shot ◽

Turbo Spin Echo ◽

Turbo Spin

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Feasibility of Total Variation Noise Reduction Algorithm According to Various MR-Based PET Images in a Simultaneous PET/MR System: A Phantom Study

Diagnostics ◽

10.3390/diagnostics11020319 ◽

2021 ◽

Vol 11 (2) ◽

pp. 319

Author(s):

Chan-Rok Park ◽

Seong-Hyeon Kang ◽

Young-Jin Lee

Keyword(s):

Image Quality ◽

Noise Reduction ◽

Total Variation ◽

Parallel Imaging ◽

Pulse Sequence ◽

Reduction Algorithm ◽

Median Filters ◽

Reduction Techniques ◽

Imaging Results ◽

Noise Reduction Algorithm

Recently, the total variation (TV) algorithm has been used for noise reduction distribution in degraded nuclear medicine images. To acquire positron emission tomography (PET) to correct the attenuation region in the PET/magnetic resonance (MR) system, the MR Dixon pulse sequence, which is based on controlled aliasing in parallel imaging, results from higher acceleration (CAIPI; MR-ACDixon-CAIPI) and generalized autocalibrating partially parallel acquisition (GRAPPA; MR-ACDixon-GRAPPA) algorithms are used. Therefore, this study aimed to evaluate the image performance of the TV noise reduction algorithm for PET/MR images using the Jaszczak phantom by injecting 18F radioisotopes with PET/MR, which is called mMR (Siemens, Germany), compared with conventional noise-reduction techniques such as Wiener and median filters. The contrast-to-noise (CNR) and coefficient of variation (COV) were used for quantitative analysis. Based on the results, PET images with the TV algorithm were improved by approximately 7.6% for CNR and decreased by approximately 20.0% for COV compared with conventional noise-reduction techniques. In particular, the image quality for the MR-ACDixon-CAIPI PET image was better than that of the MR-ACDixon-GRAPPA PET image. In conclusion, the TV noise-reduction algorithm is efficient for improving the PET image quality in PET/MR systems.

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Application of T1-weighted BLADE sequence to abdominal magnetic resonance imaging of young children: a comparison with turbo spin echo sequence

Acta Radiologica ◽

10.1177/0284185120901512 ◽

2020 ◽

Vol 61 (10) ◽

pp. 1406-1413

Author(s):

Kyu Sung Choi ◽

Young Hun Choi ◽

Jung-Eun Cheon ◽

Woo Sun Kim ◽

In One Kim

Keyword(s):

Image Quality ◽

Spin Echo ◽

Motion Artifact ◽

Turbo Spin Echo ◽

Resonance Imaging ◽

Turbo Spin ◽

Abdominal Magnetic Resonance Imaging ◽

Vessel Sharpness ◽

Corticomedullary Differentiation ◽

Lesion Conspicuity

Background The image quality of abdominal magnetic resonance imaging (MRI) in children who cannot hold their breath has been severely impaired by motion artifacts. Purpose To evaluate the usefulness of T1-weighted (T1W) BLADE MRI for axial abdominal imaging in children who cannot hold their breath. Material and Methods Two different BLADE sequences, with and without an inversion recovery (IR-BLADE), were compared to conventional turbo-spin echo (TSE) with a high number of excitations in 18 consecutive patients who cannot hold their breath. Overall image quality, motion artifact, radial artifact, hepatic vessel sharpness, renal corticomedullary differentiation, and lesion conspicuity were retrospectively assessed by two radiologists, using 4- or 5-point scoring systems. Signal variations of each sequence were measured for a quantitative comparison. The acquisition times of the three sequences were compared. Results IR-BLADE and BLADE showed significantly improved overall image quality and reduced motion artifact compared with TSE. IR-BLADE showed significantly better hepatic vessel sharpness and corticomedullary differentiation compared to both BLADE and TSE. Radial artifacts were only observed on IR-BLADE and BLADE. In nine patients with lesions, there were no significant differences in lesion conspicuity among three sequences. Compared to TSE, both IR-BLADE and BLADE showed decreased signal variations in the liver and muscle, and an increased signal variation through air. The mean acquisition times for IR-BLADE, BLADE, and TSE were comparable. Conclusion Compared to the TSE sequence, T1W IR-BLADE for pediatric abdominal MRI resulted in improved image quality, tissue contrast with a diminished respiratory motion artifact, and a comparable acquisition time.

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Rapid Lumbar Spine MR Myelography: Imaging Findings Using a Single-Shot Technique

Rivista di Neuroradiologia ◽

10.1177/197140099701000206 ◽

1997 ◽

Vol 10 (2) ◽

pp. 181-187 ◽

Cited By ~ 1

Author(s):

P. Demaerel ◽

P. Van Hover ◽

A. Broeders ◽

B. Kiefer ◽

A.L. Baert

Keyword(s):

Spin Echo ◽

Pulse Sequences ◽

Three Dimensional ◽

Projection Algorithm ◽

Fast Spin Echo ◽

Single Shot ◽

Rapid Acquisition ◽

Spin Echo Sequence ◽

Echo Pulse ◽

Mr Myelography

MR myelography has been performed by several authors. Most authors have used techniques based on three-dimensional gradient-echo pulse sequences or fast spin-echo pulse sequences. The examination time varied between 5 and 13 minutes and postprocessing with a maximum-intensity projection algorithm was necessary for three-dimensional visualization. The rapid acquisition with relaxation enhancement (RARE) was initially described by Hennig et Al. In this technical note we present our experience with a single-shot turbo spin-echo sequence, derived from RARE, of approximately 2 seconds to obtain one view. MR myelography can replace conventional myelography in all different types of pathology. In addition MR myelography provides additional information compared to MR imaging in a minority of the cases. Taking into account the ultra-rapid acquisition and the absence of postprocessing procedures, we recommended this technique in the appropriate clinical setting. The MR myelogram increases the level of conficence of the neuroradiologist.

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Increased speed and image quality in single-shot fast spin echo imaging via variable refocusing flip angles

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.24941 ◽

2015 ◽

Vol 42 (6) ◽

pp. 1747-1758 ◽

Cited By ~ 14

Author(s):

Andreas M. Loening ◽

Manojkumar Saranathan ◽

Nichanan Ruangwattanapaisarn ◽

Daniel V. Litwiller ◽

Ann Shimakawa ◽

...

Keyword(s):

Image Quality ◽

Spin Echo ◽

Fast Spin Echo ◽

Single Shot ◽

Fast Spin

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High-Resolution Simultaneous Multi-Slice Accelerated Turbo Spin-Echo Musculoskeletal Imaging: A Head-to-Head Comparison With Routine Turbo Spin-Echo Imaging

Frontiers in Physiology ◽

10.3389/fphys.2021.759888 ◽

2021 ◽

Vol 12 ◽

Author(s):

Feifei Gao ◽

Zejun Wen ◽

Shewei Dou ◽

Xiaojing Kan ◽

Shufang Wei ◽

...

Keyword(s):

Image Quality ◽

Knee Joint ◽

Ankle Joint ◽

Spin Echo ◽

Motion Artifacts ◽

Knee Joints ◽

Turbo Spin Echo ◽

Turbo Spin ◽

Scanning Time ◽

Noise Ratio

Background/Aim: The turbo spin-echo (TSE) sequence is widely used for musculoskeletal (MSK) imaging; however, its acquisition speed is limited and can be easily affected by motion artifacts. We aimed to evaluate whether the use of a simultaneous multi-slice TSE (SMS-TSE) sequence can accelerate MSK imaging while maintaining image quality when compared with the routine TSE sequence.Methods: We prospectively enrolled 71 patients [mean age, 37.43 ± 12.56 (range, 20–67) years], including 37 men and 34 women, to undergo TSE and SMS sequences. The total scanning times for the wrist, ankle and knee joint with routine sequence were 14.92, 13.97, and 13.48 min, respectively. For the SMS-TSE sequence, they were 7.52, 7.20, and 6.87 min. Quantitative parameters, including the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), were measured. Three experienced MSK imaging radiologists qualitatively evaluated the image quality of bone texture, cartilage, tendons, ligament, meniscus, and artifact using a 5-point evaluation system, and the diagnostic performance of the SMS-TSE sequences was evaluated.Results: Compared with the routine TSE sequences, the scanning time was lower by 49.60, 48.46, and 49.04% using SMS-TSE sequences for the wrist, ankle, and knee joints, respectively. For the SNR comparison, the SMS-TSE sequences were significantly higher than the routine TSE sequence for wrist (except for Axial-T2WI-FS), ankle, and knee joint MR imaging (all p < 0.05), but no statistical significance was obtained for the CNR measurement (all p > 0.05, except for Sag-PDWI-FS in ankle joint). For the wrist joint, the diagnostic sensitivity, specificity, and accuracy were 88.24, 100, and 92%. For the ankle joint, they were 100, 75, and 93.33%. For the knee joint, they were 87.50, 85.71, and 87.10%.Conclusion: The use of the SMS-TSE sequence in the wrist, ankle, and knee joints can significantly reduce the scanning time and show similar image quality when compared with the routine TSE sequence.

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Echo Planar Diffusion-Weighted Imaging: Possibilities and Considerations with 12- and 32-Channel Head Coils

Journal of Clinical Imaging Science ◽

10.4103/2156-7514.96548 ◽

2012 ◽

Vol 2 ◽

pp. 31 ◽

Cited By ~ 6

Author(s):

John N Morelli ◽

Megan R Saettele ◽

Rajesh A Rangaswamy ◽

Lan Vu ◽

Clint M Gerdes ◽

...

Keyword(s):

Image Quality ◽

Parallel Imaging ◽

Brain Magnetic Resonance Imaging ◽

Single Shot ◽

Quality Improvements ◽

Planar Imaging ◽

Diffusion Weighted ◽

Resolution Imaging ◽

Echo Planar ◽

Parallel Imaging Acceleration

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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