Improved Diagnosis of Detection of Late Enhancement in Left Ventricular Myocardium Using 2nd Generation 320-Slice CT Reconstructed with FIRST in Non-Ischemic Cardiomyopathy.

Abstract

Forward Projected Model-based Iterative Reconstruction SoluTion (FIRST) is a new reconstruction technique using CT, which provides successful reconstruction of high-quality CT images, especially in low contrast imaging. To evaluate improvements in the diagnostic accuracy of the detection of abnormal late enhancement (LE) in left-ventricular myocardium (LVM) using 320-slice CT with FIRST, we compared this modality with previous CT methods in patients with non-ischemic cardiomyopathy or a cardiac tumor.This was a retrospective study of 88 patients (56 males; 57 ± 15 years) suspected of having non-ischemic myocardial disease or a cardiac tumor. The first 52 consecutive patients (Group 1) underwent 16-slice CT at 140 kV tube voltage and an average tube current of 337 ± 20 mA, and 1.5 T MRI. The next 18 patients (Group 2) underwent 1st generation 320-slice CT at 120 kV tube voltage and an average tube current of 255 ± 106 mA, and 1.5T MRI; the remaining 18 patients (Group 3) underwent 2nd generation 320-slice CT with FIRST, at 80 kV tube voltage and a tube current of 800 mA, and 1.5T or 3T MRI.On patient-based analysis, no significant differences were observed between the 3 groups. For segment-based analysis, the specificity and overall accuracy were significantly higher (both P < 0.05) in Group 3 than in Group 1. Positive predictive value (PPV) was significantly higher in Group 3 than in Groups 1 and 2.The diagnostic accuracy of LE on CT for detecting myocardial fibrosis determined by late gadolinium-enhanced MRI was improved with the use of 2nd generation 320-slice CT with FIRST, in particular regarding specificity, PPV, and overall accuracy.