Perfusion imaging

TLDR

The study aims to measure tissue perfusion for functional organ assessment in vivo. The authors employed 1H NMR imaging with slice‑selective saturation of blood water in the neck to generate endogenous tracer‑based perfusion maps of the rat brain at 4.7 T, using the exchange of saturated spins with bulk water and distal saturation as a control. The technique produced a mean cerebral blood flow of 105 ± 16 cc · 100 g⁻¹ min⁻¹, consistent with literature values and responsive to arterial pCO₂, demonstrating that noninvasive 1H MRI perfusion maps can be obtained and are potentially translatable to humans. © 1992 Academic Press, Inc.

Abstract

Abstract Measurement of tissue perfusion is important for the functional assessment of organs in vivo. Here we report the use of 1 H NMR imaging to generate perfusion maps in the rat brain at 4.7 T. Blood water flowing to the brain is saturated in the neck region with a sliceselective saturation imaging sequence, creating an endogenous tracer in the form of proximally saturated spins. Because proton T 1 times are relatively long, particularly at high field strengths, saturated spins exchange with bulk water in the brain and a steady state is created where the regional concentration of saturated spins is determined by the regional blood flow and regional T 1 . Distal saturation applied equidistantly outside the brain serves as a control for effects of the saturation pulses. Average cerebral blood flow in normocapnic rat brain under halothane anesthesia was determined to be 105 ± 16 cc. 100 g −1 . min −1 (mean ± SEM, n = 3), in good agreement with values reported in the literature, and was sensitive to increases in arterial p CO 2 . This technique allows regional perfusion maps to be measured noninvasively, with the resolution of 1 H MRI, and should be readily applicable to human studies. © 1992 Academic Press, Inc.