Assessing myocardial perfusion is a key issue in the diagnosis and subsequent treatment of patients with coronary artery disease (CAD).^1,2 A single magnetic resonance (MR) examination can assess perfusion by monitoring the upslope of the signal change in dependence on the first pass of gadolinium derivatives. We propose a method of evaluating the regional distribution of the perfusion reserve index (PRI), defined as the ratio between stress and resting upslopes. The PRI regional distribution was assessed in patients with and without CAD and a PRI cut off was identified.

METHODS

Thirty two patients (mean (SD) age 65 (10) years, 20 men) underwent MR imaging and quantitative coronary angiography to assess the presence of coronary artery stenoses. The protocol was approved by the institutional ethics committees and informed consent was obtained from all patients.

MR images were acquired with a GE Signa 1.5 T scanner during gadolinium-diethylenetriaminepentaacetic acid (DTPA) infusion (Omniscan, Nycomed Imaging, Roskilde, Denmark) into a cubital vein (0.1 mmol/kg, 5 ml/s) followed by 10 ml of saline flush. A cardiac array coil was used, with fast gradient echo with an echo train readout sequence. For each examination, three 256 × 256 short axis slices (basal, middle, and distal) were acquired in the diastolic phase during an RR interval with a slice thickness of 8 mm. The acquisition was repeated along 60 RR intervals. All the patients were asked to hold their …