Segmented turboFLASH: method for breath-hold MR imaging of the liver with flexible contrast.

Edelman, Robert R.; Wallner, Bernd; Singer, AM; Atkinson, D; Saini, Savita

doi:10.1148/radiology.177.2.2171014

Cited by 127 publications

(48 citation statements)

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“…Sequential transverse images of the abdominal aorta, from the renal arteries to the iliac bifurcation, were obtained with a T1-weighted, 2D, segmented gradient-echo sequence (TFL) (1) with an IR preparatory pulse 17 (IR-TFL) and (2) with a combination of IR and diffusion-based flow suppression prepulse 18 (IR-DIFF-TFL). T1-weighted imaging was performed before and after administration of gadofluorine (immediately after injection [up to 1 hour] and 24 hours after injection).…”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Lipid-Rich Atherosclerotic Plaques Detected by Gadofluorine-Enhanced In Vivo Magnetic Resonance Imaging

et al. 2004

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Background-MRI of specific components in atherosclerotic plaque may provide information on plaque stability and its potential to rupture. We evaluated gadofluorine in atherosclerotic rabbits using a new MR sequence that allows plaque detection within 1 hour after injection and assessed enhancement in lipid-rich and non-lipid-rich plaques. Methods and Results-Twelve rabbits with aortic plaque and 6 controls underwent MRI before and up to 24 hours after gadofluorine injection (50 mol/kg). Two T1-weighted, segmented gradient-echo sequences (TFL) were compared to enhance vessel wall delineation after injection: (1) an inversion-recovery prepulse (IR-TFL) or (2) a combination of inversion-recovery and diffusion-based flow suppression prepulses (IR-DIFF-TFL). With the use of IR-TFL at 1 hour after injection, the vessel wall was not delineated because of poor flow suppression; at 24 hours after injection, the enhancement was 37% (PϽ0.01). IR-DIFF-TFL showed significant enhancement after versus before contrast (1 . There was no enhancement in the vessel wall after gadofluorine injection in the control group. A strong correlation was found (r 2 ϭ0.87; PϽ0.001) between the lipid-rich areas in histological sections and signal intensity in corresponding MR images. This suggests a high affinity of gadofluorine for lipid-rich plaques. Conclusions-Gadofluorine-enhanced MRI improves atherosclerotic plaque detection. The IR-DIFF-TFL method allows early detection of atherosclerotic plaque within 1 hour after gadofluorine injection.

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Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Lipid-Rich Atherosclerotic Plaques Detected by Gadofluorine-Enhanced In Vivo Magnetic Resonance Imaging

et al. 2004

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“…Measurements were also made of the length of stenosis and the distance from the arterial origin. Absolute measurements were calculated from the known width of the 7 Assessment of coronary artery stenosis by magnetic resonance imaging inclination of the artery was measured directly from the transaxial magnetic resonance images. When the arterial angle differed from the known projection angle, the foreshortening effect was corrected by simple geometry.…”

Section: Analysis Of Coronary Angiogramsmentioning

confidence: 99%

Assessment of coronary artery stenosis by magnetic resonance imaging.

Pennell

Bogren

Keegan

et al. 1996

Heart

150

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Objective-The findings of magnetic resonance and x-ray angiography were compared for assessment of coronary artery stenosis in this validation study. Background-Magnetic resonance angiography of the coronary arteries has recently been described, but there has been no comparison with x-ray angiography of localisation or assessment of important characteristics of coronary stenosis. Methods-A breath hold, segmented kspace, 2D gradient echo imaging technique incorporating fat suppression was used in 39 patients (55 coronary stenoses) with known coronary artery disease. Results-Overall, 47 stenoses (85%) were assessed by magnetic resonance (29 of 33 stenoses in the left anterior descending artery, one of one in the left main stem, 14 of 17 in the right coronary artery, and three of four in the left circumflex artery were detected). There was close agreement between magnetic resonance and xray angiography for the distance of the stenosis from the arterial origin (magnetic resonance mean (SD) 27 (16) mm versus x-ray angiography 27 (16) mm, P = NS, mean difference -0-2 mm). The distance to 39 stenoses (83%) agreed to within 5 mm, with increased scatter for more distal stenoses. The severity of magnetic resonance signal loss, assessed visually at the site of stenosis, varied significantly according to the percentage diameter stenosis (F = 30, P < 0-0001); stenosis severity with severe signal loss was 89 (7)%, with partial signal was 70 (16)%, and with irregular wall only 37 (11)%, with significant differences among the three groups (P < 0.001). A significant correlation was found between the proportional magnetic resonance signal loss at the stenosis and the percentage diameter stenosis severity (r = -0-67, P < 0.0001). The length of stenosis measured by magnetic resonance (6 (3) mm) was greater than by x-ray angiography (5 (2) mm, P < 0-006, mean difference + 1 1 mm). Spearman's rank test showed that there was significant overestimation of stenosis length by magnetic resonance as stenosis severity increased (r. = 0 34, P < 0.02).Conclusions-Accurate localisation of coronary stenosis and a qualitative assessment of stenosis severity are possible by magnetic resonance, but stenosis length is overestimated as severity increases, probably because of disturbed patterns of flow with turbulence distal to severe stenoses. Reasonable results for the detection of coronary artery stenosis by magnetic resonance were achieved in this highly selected population, but further progress in imaging techniques is necessary before moving towards appreciable clinical application. (Heart 1996;75:127-133) Keywords: coronary artery stenosis; magnetic resonance angiography; x-ray angiography Imaging of the coronary arteries to localise stenosis, measure severity and assess the distal vessel is important in the management of coronary artery disease, and is essential before revascularisation by coronary bypass surgery or angioplasty. The invasive technique developed over the past 35 years, however, uses intra-arterial catheterisation an...

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“…Segmented acquisitions [39] acquire only a fraction of the k-space data required for each image during one repetition of the test phrase and, hence, require multiple identical repetitions. While these segmented techniques permit high temporal and spatial resolutions [35], they require reproducible production of the same phrase up to 256 times [34], leading to subject fatigue.…”

mentioning

confidence: 99%

Towards clinical assessment of velopharyngeal closure using MRI: evaluation of real-time MRI sequences at 1.5 and 3 T

Scott

Boubertakh²,

Birch³

et al. 2012

The British Journal of Radiology

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Objective: The objective of this study was to demonstrate soft palate MRI at 1.5 and 3 T with high temporal resolution on clinical scanners. Methods: Six volunteers were imaged while speaking, using both four real-time steady-state free-precession (SSFP) sequences at 3 T and four balanced SSFP (bSSFP) at 1.5 T. Temporal resolution was 9-20 frames s 21 (fps), spatial resolution 1.661.6610.0-2.762.7610.0 mm 3 . Simultaneous audio was recorded. Signal-to-noise ratio (SNR), palate thickness and image quality score (1-4, non-diagnostic-excellent) were evaluated. Results: SNR was higher at 3 T than 1.5 T in the relaxed palate (nasal breathing position) and reduced in the elevated palate at 3 T, but not 1.5 T. Image quality was not significantly different between field strengths or sequences (p5NS). At 3 T, 40% acquisitions scored 2 and 56% scored 3. Most 1.5 T acquisitions scored 1 (19%) or 4 (46%). Image quality was more dependent on subject or field than sequence. SNR in static images was highest with 1.961.9610.0 mm 3 resolution (10 fps) and measured palate thickness was similar (p5NS)

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Segmented turboFLASH: method for breath-hold MR imaging of the liver with flexible contrast.

Cited by 127 publications

References 0 publications

Lipid-Rich Atherosclerotic Plaques Detected by Gadofluorine-Enhanced In Vivo Magnetic Resonance Imaging

Lipid-Rich Atherosclerotic Plaques Detected by Gadofluorine-Enhanced In Vivo Magnetic Resonance Imaging

Assessment of coronary artery stenosis by magnetic resonance imaging.

Towards clinical assessment of velopharyngeal closure using MRI: evaluation of real-time MRI sequences at 1.5 and 3 T

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