Comparison of multi-delay FAIR and pCASL labeling approaches for renal perfusion quantification at 3T MRI

Abstract

Objective To compare the most commonly used labeling approaches, flow-sensitive alternating inversion recovery (FAIR) and pseudocontinuous arterial spin labeling (pCASL), for renal perfusion measurement using arterial spin labeling (ASL) MRI. Methods Multi-delay FAIR and pCASL were performed in 16 middle-aged healthy volunteers on two different occasions at 3T. Relative perfusion-weighted signal (PWS), temporal SNR (tSNR), renal blood flow (RBF), and arterial transit time (ATT) were calculated for the cortex and medulla in both kidneys. Bland-Altman plots, intra-class correlation coefficient, and within-subject coefficient of variation were used to assess reliability and agreement between measurements. Results For the first visit, RBF was 362 ± 57 and 140 ± 47 mL/min/100 g, and ATT was 0.47 ± 0.13 and 0.70 ± 0.10 s in cortex and medulla, respectively, using FAIR; RBF was 201 ± 72 and 84 ± 27 mL/min/100 g, and ATT was 0.71 ± 0.25 and 0.86 ± 0.12 s in cortex and medulla, respectively, using pCASL. For both labeling approaches, RBF and ATT values were not significantly different between visits. Overall, FAIR showed higher PWS and tSNR. Moreover, repeatability of perfusion parameters was better using FAIR. Discussion This study showed that compared to (balanced) pCASL, FAIR perfusion values were significantly higher and more comparable between visits.

Multi‐organ comparison of flow‐based arterial spin labeling techniques: Spatially non‐selective labeling for cerebral and renal perfusion imaging

“…We found a 3× higher tSNR for FAIR compared to pCASL. Similar differences were found in a previous study, 24 where a detailed discussion is provided on the reasons why pCASL performed worse than FAIR in kidney at 3T, given that the opposite is true for the brain. Advantages of pCASL in brain include labeling closer to the imaging region and having a longer temporal bolus.…”

Hyperpolarized 129Xe Time-of-Flight MR Imaging of Perfusion and Brain Function

“…Recently, multiple advances in ASL perfusion imaging were achieved by developing a pseudo-continuous ASL (pCASL), resulting in an SNR increase compared to conventional ASL [ 16 , 17 , 18 , 53 ]. pCASL perfusion images have higher spatial resolution compared to the present HP 129 Xe TOF images, mainly due to their significantly better developed hardware (multichannel coils used for parallel imaging during perfusion imaging) and software available for conducting proton ASL MRI.…”

“…SNR maps were created by dividing each pixel by the standard deviation of the noise region. Based on Killian's model of dissolved Xe 18 , the mathematical theory was generalized and applied for HP 129 Xe perfusion mapping (for a detailed explanation, see Supplementary Material S1). Three SNR maps created from TOF images and acquired with different recovery times were fitted pixel-by-pixel using the linear equation of the SNR delay time dependence (see Supplementary Material S2), and slope maps were created.…”

“…Perfusion measurements can provide vital information about the homeostasis of an organ [ 1 ] and can therefore be used as biomarkers to diagnose cardiovascular [ 2 , 3 ], renal [ 4 ], and neurological [ 5 , 6 , 7 ] diseases. Currently, the most commonly used techniques to measure perfusion are 15 O positron emission tomography (PET) [ 8 , 9 , 10 ], xenon-enhanced computed tomography (CT) [ 11 , 12 ], single photon emission computed tomography (SPECT) [ 3 , 8 , 13 ], and arterial spin labeling (ASL) magnetic resonance imaging (MRI) [ 1 , 14 , 15 , 16 , 17 , 18 ]. In addition, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI are frequently used for perfusion imaging [ 19 , 20 , 21 ].…”

Multiparametric Renal MRI: An Intrasubject Test–Retest Repeatability Study

“…Care was taken to acquire T 1 maps, ASL images, and M 0 images using the same field of view and voxel size, since these images had to be combined for ASL quantification. For timing of the QUIPPS settings in the flow attenuated inversion recovery arterial spin labeling (FAIR‐ASL) acquisition, please refer to the previous study 13 . For the first four patients a slightly different scan protocol for T 1 mapping and FAIR‐ASL was used.…”