Imaging of myocardial infarction using a 64-slice MDCT scanner: Correlation between infarcted region and status of territory-dependent coronary artery

Abstract

This study was performed to evaluate the ability of 64-slice multidetector computed tomography (MDCT) to detect previous myocardial infarctions (MIs) in patients referred for the assessment of the coronary arteries. In patients with regional changes of left ventricular wall myocardial density, the territory-dependent coronary vessel status was examined. We retrospectively assessed 202 consecutive patients referred for 64-slice MDCT of the coronary arteries. In all cases, detailed, clinical, serological and electrocardiograph (ECG) data were collected to identify patients with a previous diagnosis of MI. An initial qualitative evaluation of MDCT images was performed in all patients to identify areas of suspected myocardial necrosis, which were defined as regions of lower density within normally enhanced left ventricular myocardium. Thereafter, in all patients with suspected MIs, attenuation values and left ventricular wall thickness were also measured at the level of the normal myocardium and within the hypodense regions. Each MI was also assigned to the distribution territory of a coronary vessel, and morphological data were combined with MDCT angiographic findings. After clinical assessment, MI was found in 27 patients (six acute).; 64-slice MDCT was able to detect the presence of MI in 24/27 cases, showing sensitivity and specificity of 89% and 95%, respectively, and an overall diagnostic accuracy of 95%. Quantitative analysis showed a significant difference (p<0.01) between attenuation values of normal vs. infarcted myocardium (124.5+/-19 HU vs. 56.1+/-23 HU, respectively); wall thinning was exclusively observed in chronic MIs (p<0.01). In 23/24 detected cases, analysis of territory-dependent arteries showed findings compatible with presence of MI. The presence of MI is well depicted with retrospective 64-slice MDCT. The main advantage of 64-slice MDCT is that it allows to evaluate and relate the status of a vessel and its dependent myocardial region in a single exam.