939-82 Efficacy of Gadolinium-BOPTA in Magnetic Resonance Imaging to Assess Acute Myocardial Infarction in Man

Abstract

To assess the efficacy of the newly developed contrast agent gadolinium (Gd) benzyloxy propionic tetraacetic-acid BOPTA to detect acute myocardial infarction in patients using magnetic resonance imaging (MRI), 24 patients (age 53.3 ± 8.3) were examined 9.3 ± 3.7 days after a first myocardial infarction. Short axis Tl weighted images were obtained at 3 slice levels, before, immediately after injection of Gd-BOPTA, and after 15 min, 30 min, 45 min. Patients were divided into 2 groups according to the dose of Gd-BOPTA (0.05 mmol/kg and 0.1 mmol/kg). Contrast to noise ratio, signal intensity enhancement of normal and infarcted myocardium and signal intensity of infarcted to signal intensity of normal myocardium (SI inf/norm) was quantified. Contrast to noise ratio was not affected by the type of dosage (0.05 mmol/kg, 5.75 ± 0.85 vs. 0.1 mmol/kg, 5.32 ± 0.69). Enhancement of normal and infarcted myocardium increased immediately after administration of 0.05 mmol/kg Gd-BOPTA and gradually decreased thereafter (p < 0.002 for normal myocardium) (see Figure). After 0.1 mmol/kg Gd-BOPTA administration, myocardial enhancement increased rapidly but showed no decrease within 45 minutes after administration (see Figure). Mean SI inf/norm was significantly improved after Gd-BOPTA administration (p < 0.0005 for either dosage), and 0.05 mmol/kg produced significantly higher SI inf/norm than 0.1 mmol/kg (1.42 ± 0.069 vs. 1.34 ± 0.055 respectively, p = 0.015). Gd BOPTA is a useful contrast agent to assess myocardial infarction. Optimal results are obtained with a dosage of 0.05 mmol/kg body weight Gd-BOPTA. Persistent enhancement of infarcted and normal myocardium suggests an affinity of Gd-BOPTA for myocytes, making it a promising tool in MR imaging of ischemic heart disease.