Perfusion-corrected mapping of cardiac regional blood volume in rats in vivo

Measurement of regional blood volume (RBV) in the myocardium in vivo is imp ortant for the assessment of tissue viability and function, The method in t his work is based on the acquisition of a T-1 map before and after intravas cular contrast agent application, It is known that this method is influence d by perfusion that causes an overestimation of REV values, In order to sol ve this problem, the new method is proposed which acquires T1 maps with sli ce selective inversion pulses, Due to blood flow nonexcited spins enter the detection slice, which leads to an acceleration of the relaxation time. A model that divides tissue into two compartments is adapted to slice selecti ve inversion in order to derive a simple expression for perfusion-corrected REV. The aim of the study is to demonstrate the feasibility and accuracy o f this technique for quantification of REV in rat myocardium in vivo, REV m aps were obtained for five rats, and the reproducibility was determined by repeating the experiment several times. A mean REV value of 12.8 +/- 0.7% ( v/v) over all animals was obtained in the myocardium. The results were comp ared with REV maps obtained with perfusion-sensitive REV imaging in the sam e five rats and with first-pass REV studies, In order to demonstrate the st rength of the new method the vasodilator adenosine was administered and alt erations in microcirculation were imaged. (C) 1999 Wiley-Liss, Inc.