Accurate myocardial T1 measurements: Toward quantification of myocardial blood flow with arterial spin labeling

✍ Scribed by Haosen Zhang; Steve M. Shea; Vivian Park; Debiao Li; Pamela K. Woodard; Robert J. Gropler; Jie Zheng

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 519 KB
• Volume: 53
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.20461

✦ Synopsis

Abstract

In this study, we investigated a method for accurately measuring myocardial T~1~ for the quantification of myocardial blood flow (MBF) with arterial spin labeling (ASL). A single‐shot gradient‐echo (GE)‐based ASL sequence with an adiabatic hyperbolic secant inversion recovery pulse was modified to acquire a pair of myocardial T~1~'s within a breath‐hold. A multivariable regression algorithm that accounted for the magnetization saturation effects was developed to calculate T~1~. The MBF was then determined with a well‐developed model. The accuracy of our T~1~ calculation was first evaluated in a phantom, and then in six dogs for the MBF calculation, with (N = 4) and without (N = 2) coronary artery stenosis. In the phantom study, the accuracy of T~1~ measured with a slice‐selective inversion prepared pulse was within 2.5% of error. In healthy dogs, the MBF increased 2–5 times during vasodilation. In contrast, regional differences of MBF were well visualized in the stenotic dogs during vasodilation (perfusion reserve of 2.75 ± 0.83 in normal myocardium, and 1.46 ± 0.75 in the stenotic area). A correlation analysis revealed a close agreement in MBF between the ASL and microsphere (MS) in both healthy and stenotic dogs. In summary, the modified ASL technique and T~1~ regression algorithm proposed here provide an accurate measurement of myocardial T~1~ and demonstrate potential for reliably assessing MBF at steady state. Magn Reson Med 53:1135–1142, 2005. © 2005 Wiley‐Liss, Inc.