Comparison of MDCT and MRI in the detection and sizing of acute and chronic myocardial infarcts

Purpose: This study compared ability of multidetector computed tomography (MDCT) to detect and size the myocardial infarctions (MI) with MRI. Materials and methods: Eighty examination sets of MDCT and MRI of 63 consecutive patients in the acute stage (average 6.3 days, n = 40) and/or chronic stage (average, 11.8 months; n = 40) of reperfused MI were examined in this study. The first-pass and delayed MRI was performed using a 1.5 T scanner with an injection of Gd-DTPA to assess the extent of MI. Within 24 h after MRI, MDCT was performed at the arterial phase around 25 s with a 10-min delay using one of the following scanners: 4-slice, 16-slice, and 40-slice. The volume of the MI over the total myocardial volume was calculated from the MRI and CT images. Results: MDCT revealed MI lesions in all cases except for one (1.3%) on the early phase images. The percentage volume of the lesion on the MDCT images correlated with that of the MR images. The correlation coefficient between perfusion MRI and early CT was 0.62 (p < 0.0001) and the correlation coefficient between the 5-min delay MRI and late CT was 0.81 (p < 0.0001). There was no significant difference in the average lesion volume (%) between perfusion MRI (10.8 ± 6.7%) and early CT (12.1 ± 8.5%) (p > 0.05), but there was significant difference between the 5-min delay MRI (25.9 ± 12.1%) and late CT (22.8 ± 11.8%) (p < 0.001). Conclusion: MDCT produces comparable results to MRI in the detection and sizing of acute and chronic MI