Myocardial arterial spin labeling

Liver metabolism leads to statistically significant overestimation of cardiac lactate production in slice-selective or nonselective spectroscopic experiments. Therefore, metabolic imaging is preferred over spectroscopy to separate left-ventricular compartments within the slice and hence avoid contamination of cardiac lactate signals. Alternatively, presaturation pulses should be used in combination with spectroscopy approaches.

Section: Discussionmentioning

confidence: 99%

Overestimation of cardiac lactate production caused by liver metabolism of hyperpolarized [1‐¹³C]pyruvate

Wespi

Steinhauser

Kwiatkowski

et al. 2018

“…Arterial spin labeled cardiac MR (ASL‐CMR) is a noncontrast technique that can assess myocardial perfusion (MP) and detect angiographically significant coronary artery disease (CAD) . Approximately 17.6 million Americans suffer from CAD, and it is responsible for more than 350 thousand deaths in the United States each year .…”

Section: Introductionmentioning

confidence: 99%

“…There is a growing need for a safe and repeatable method to assess CAD. Cardiac ASL can be beneficial in this regard, because it uses no ionizing radiation or contrast agents, it provides a quantitative MP measurement, and it can be used repeatedly or even continuously to measure MP without any risk to the patients …”

Section: Introductionmentioning

confidence: 99%

Single‐shot EPI for ASL‐CMR

Javed

Nayak

2020

Self Cite

Purpose: To evaluate single-shot echo planar imaging (SS-EPI), as an alternative to snapshot balanced steady state free precession (bSSFP) imaging, for arterialspin-labeled cardiac MR (ASL-CMR). This study presents a practical implementation SS-EPI tailored to the needs of ASL-CMR at 3T and demonstrates sequential multi-slice ASL with no increase in scan time. Methods: Reduced field of view SS-EPI was performed using a 2DRF pulse. A spinecho was used with crushers optimized to maximize blood suppression and minimize myocardial signal loss, based on experiments in 4 healthy volunteers. SS-EPI was evaluated against the widely used bSSFP reference method in single-slice ASL-CMR in 4 healthy volunteers, during both systole and diastole. Sequential multi-slice ASL-CMR with SS-EPI was demonstrated during diastole (3 slices: basal, mid, and apical short-axis) and during systole (2 slices: mid and apical short-axis), in 3 volunteers. Results: Global myocardial perfusion for diastolic SS-EPI (1.66 ± 0.73 mL/g/min) and systolic SS-EPI (1.50 ± 0.36 mL/g/min) were found to be statistically equivalent (2 one-sided test with a difference of 0.4 mL/g/min) to diastolic bSSFP (duration of 1 cardiac cycle, 1.60 ± 0.80 mL/g/min) with P-values of 0.022 and 0.031, respectively.Global myocardial perfusion for sequential multi-slice experiments was 1.64 ± 0.47, 1.34 ± 0.29, and 1.88 ± 0.58 for basal, mid, and apical SAX slices during diastole and was 1.61 ± 0.35, and 1.66 ± 0.49 for mid and apical slice during systole. These values are comparable to published ASL-CMR and positron emission tomography studies. Conclusion: SS-EPI is a promising alternative to bSSFP imaging for ASL-CMR and can potentially improve the spatial coverage of ASL-CMR by 3-fold during diastole and 2-fold during systole, without increasing scan time.

“…3 In addition, ASL can be used to assess perfusion in other organs of the body. [4][5][6] Renal ASL holds great potential, given that it provides quantification of a crucial pathophysiological parameter of kidney disease: renal blood flow (RBF). Furthermore, it achieves this without requiring injection of MR contrast agents, which are typically contraindicated for patients with impaired renal function.…”

Section: Introductionmentioning

confidence: 99%

Robust kidney perfusion mapping in pediatric chronic kidney disease using single‐shot 3D‐GRASE ASL with optimized retrospective motion correction

Nery

Vita

Clark

et al. 2018

Purpose To develop a robust renal arterial spin labeling (ASL) acquisition and processing strategy for mapping renal blood flow (RBF) in a pediatric cohort with severe kidney disease. Methods A single‐shot background‐suppressed 3D gradient and spin‐echo (GRASE) flow‐sensitive alternating inversion recovery (FAIR) ASL acquisition method was used to perform 2 studies. First, an evaluation of the feasibility of single‐shot 3D‐GRASE and retrospective noise reduction methods was performed in healthy volunteers. Second, a pediatric cohort with severe chronic kidney disease underwent single‐shot 3D‐GRASE FAIR ASL and RBF was quantified following several retrospective motion correction pipelines, including image registration and threshold‐free weighted averaging. The effect of motion correction on the fit errors of saturation recovery (SR) images (required for RBF quantification) and on the perfusion‐weighted image (PWI) temporal signal‐to‐noise ratio (tSNR) was evaluated, as well as the intra‐ and inter‐session repeatability of renal longitudinal relaxation time (T1) and RBF. Results The mean cortical and/or functional renal parenchyma RBF in healthy volunteers and CKD patients was 295 ± 97 and 95 ± 47 mL/100 g/min, respectively. Motion‐correction reduced image artefacts in both T1 and RBF maps, significantly reduced SR fit errors, significantly increased the PWI tSNR and improved the improved the repeatability of T1 and RBF in the pediatric patient cohort. Conclusion Single‐shot 3D‐GRASE ASL combined with retrospective motion correction enabled repeatable non‐invasive RBF mapping in the first pediatric cohort with severe kidney disease undergoing ASL scans.