FAIR true‐FISP perfusion imaging of the kidneys

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Purpose:To investigate the feasibility of perfusion imaging of the pancreas using an arterial spin labeling (ASL) technique. Materials and Methods:An adapted flow-sensitive alternating inversion recovery (FAIR)-TrueFISP ASL technique was implemented on a 1.5T scanner. Anatomical and perfusion imaging in three different parts of the pancreas were performed in 10 healthy volunteers. Quantitative perfusion values were calculated using the extended Bloch equations.Results: Perfusion images of all subjects showed diagnostic image quality in the pancreatic tail and the head. Assessment of pancreatic tissue perfusion was possible in all organ parts. Mean perfusion values were 271 Ϯ 79 mL/ 100g/min in the head, 351 Ϯ 112 mL/100g/min in the body, and 243 Ϯ 55 mL/100g/min in the tail of the pancreas. Total examination time for perfusion imaging of the entire organ was 15.4 minutes. Conclusion:FAIR-TrueFISP permits analysis of pancreatic tissue perfusion with good image quality in a clinically applicable measuring time. Assessment of perfusion disorders may be useful in the diagnosis of inflammatory pancreatic pathologies, endocrine and exocrine pancreatic disorders, and in monitoring of pancreatic transplants.

Section: Perfusion Imaging Techniquementioning

confidence: 99%

Perfusion imaging of the pancreas using an arterial spin labeling technique

Schraml

Schwenzer

Martirosian³

et al. 2008

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“…We used a version of FAIR-TrueFISP optimized for perfusion imaging of the kidneys as previously described (18). In short, each FAIR preparation was followed by data recording of one entire slice, with TR ϭ 4.8 msec, TE ϭ 2.4 msec, and acquisition bandwidth for the True-FISP sequence ϭ 651 Hz/pixel.…”

Section: Fair-truefisp Imagingmentioning

confidence: 99%

“…We computed the quantitative perfusion images on a pixel-by-pixel basis from the analysis of the magnetization difference ⌬M, the tissue equilibrium magnetization M 0 , and the T1 maps using the following equation (10,18):…”

Section: Computation Of Quantitative Perfusion Mapsmentioning

confidence: 99%

FAIR‐TrueFISP imaging of cerebral perfusion in areas of high magnetic susceptibility differences at 1.5 and 3 Tesla

Boss

Martirosian

Klose

et al. 2007

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Purpose:To estimate cerebral blood perfusion in areas of strong magnetic susceptibility changes with high spatial and temporal resolution using a flow-sensitive alternating inversion recovery (FAIR) arterial spin labeling (ASL) method. Materials and Methods:We implemented an ASL method that is capable of imaging perfusion in areas of high magnetic susceptibility changes by combining a FAIR spin preparation with a true fast imaging in steady precession (TrueFISP) data acquisition strategy. A TrueFISP readout sequence was applied especially in regions with magnetic field inhomogeneities and compared with corresponding FAIR measurements obtained with a standard echo-planar imaging (EPI) readout. Quantitative perfusion images were obtained at 1.5 Tesla (1.5T) from eight healthy volunteers (24 -42 years old) and one patient (23 years old). FAIRTrueFISP perfusion images were compared with FAIR echoplanar images. T1 maps, which are necessary for quantitative perfusion estimation, were obtained with inversion recovery (IR) TrueFISP and IR EPI. Additionally, high-resolution perfusion measurements were performed on four volunteers at 3T. Results:The two ASL perfusion imaging modalities yielded comparable diagnostic image quality in brain areas with low susceptibility differences at 1.5T. Cerebral perfusion of gray matter (GM) areas was 105.7 Ϯ 5.2 mL/100 g/minute for FAIR-TrueFISP and 88.8 Ϯ 14.6 mL/100 g/minute for FAIR-EPI at 1.5T, and 70.4 Ϯ 7.1 mL/100 g/minute for FAIR-TrueFISP and 63.5 Ϯ 6.9 mL/100 g/minute for FAIR-EPI at 3.0T. Higher perfusion values at 1.5T were due to more pronounced partial-volume effects from fast moving spins at lower spatial resolution. The FAIR-TrueFISP sequence showed no significant distortions and markedly reduced signal void artifacts in areas of high susceptibility changes (e.g., near brain-bone transitions and close to metallic clips) compared to FAIR-EPI. At 3T, highly resolved FAIR-TrueFISP perfusion images were acquired with an in-plane resolution of up to 1.3 mm.Conclusion: FAIR-TrueFISP allows for assessment of cerebral perfusion in areas of critically high susceptibility changes with conventional ASL methods.

“…This technique was discussed earlier. Although many publications report on technical feasibility, quantification of ASL renal perfusion at 3.0T or reports on the clinical value of ASL-perfusion measurements are lacking, and this technique has not (yet) entered clinical routine (77)(78)(79)(80). This is likely due to ASL techniques being hampered by artifacts, lacking in technical robustness, and (in comparison to the contrast-enhanced renal perfusion techniques) being relatively time-consuming and unable to determine split renal function.…”

Section: Functional Mr Imaging Of the Kidneysmentioning

confidence: 99%

Renovascular imaging in the NSF Era

Roditi

Maki

Oliveira

et al. 2009

The detection of the association between nephrogenic systemic fibrosis (NSF), a rare but potentially life‐threatening disease only encountered in patients with severely impaired renal function, and the previous administration of some Gd‐chelates has cast a shadow on the administration of Gd‐chelates in patients with chronic renal failure. So far, contrast‐enhanced MR‐angiography (MRA) was considered the best diagnostic modality in patients with suspected renal disease. This review explores the most appropriate use of renal MRA with a focus on newly developed nonenhanced MRA techniques. Nonenhanced MRA techniques mainly based on SSFP with ECG‐gating allow for acceptable spatial resolution to visualize at least the proximal parts of the renal arteries. In addition functional renal imaging techniques and their current clinical role are critically appreciated. J. Magn. Reson. Imaging 2009;30:1323–1334. © 2009 Wiley‐Liss, Inc.