[Study of early myocardial infarction by nuclear magnetic resonance imaging with gadolinium Dota injection].

Ten patients with acute myocardial infarction were studied by magnetic resonance imaging (MRI) with injection of a paramagnetic contrast agent: Gadolinium-DOTA (Gd-DOTA). The time interval between the onset of symptoms and MRI was 8 to 12 days. The site of infarction was determined in all cases by Thallium 201 scintigraphy (hypofixation) and selective ventriculography (segmental wall anomalies): anterior (6 cases), inferior (4 cases). MRI was performed with a 0.5 Tesla CGR Magniscan by the multiple spin technique. A series of tomographic sections was recorded immediately after intravenous injection of 0.4 mmol/Kg of Gd-DOTA. Recent myocardial infarction with parenchymal oedema gives an enhanced transmural signal: only 3 patients had a sufficiently contrasted image on the 1st spin echo. After Gd-DOTA, 7 patients had significantly increased contrast on this echo and in all excellent contrast between infarcted and healthy myocardium was obtained in 9 of the 10 patients. There was excellent correlation concerning the site of infarction between Thallium scintigraphy and left ventriculography. The intensity of signal and T2 relaxation time of different myocardial segments was studied by the regions of interest technique: the ratio of signal intensity of infarcted/healthy myocardium was 1.3 before and 1.7 after Gd-DOTA on first spin echo images. The mean T2 was 54.1 +/- 9 ms in healthy and 82 +/- 28 ms in infarcted myocardium. After Gd-DOTA, both values decreased and tended to equalize.(ABSTRACT TRUNCATED AT 250 WORDS)