Is multidetector computed tomography a suitable alternative to MR imaging for the assessment of myocardial necrosis after alcohol septal ablation?

BACKGROUND

To compare magnetic resonance (MR) imaging and multidetector computed tomography (MDCT) for the assessment of myocardial infarction (MI) after alcohol septal ablation (ASA).

METHODS

Ten patients (mean age, 60 years ± 16) were examined with both MDCT and 1.5-T MR imaging performed 10 minutes after injection, within 3 days after ASA. Half of them had a temporary pacemaker (PM) during MDCT examination. Global image quality (IQ) and localization of MI were noticed on both MDCT and MR images. Volumes of MI, contrast-to-noise ratios (CNR) and signal-to-noise ratios (SNR) were also calculated. ASA effectiveness was evaluated by echocardiography immediately and 3 months after procedure.

RESULTS

Global IQ was considered adequate for both procedures. In 8 patients, MI reached the basal part of the septum on both MDCT and MR images. The 2 remaining patients exhibited sparing of the basal septum on MDCT and MR images. Volumes of MI were within the same range with the 2 techniques (MDCT: 22.1 ± 8.8 mL; MR imaging: 23.8 ± 9.4 mL) and correlated well each other (R(2)=0.85, p<0.002). The 2 patients with sparing of the basal interventricular septum had persistent gradient on echocardiography 3 months after ASA, suggesting failure of the procedure. The volumes of MI didn't correlate with the reduction of pressure gradient on echocardiography 3 months after ASA (R(2)=0.02, p<0.05).

CONCLUSIONS

Evaluation of post ASA MI is feasible with MDCT by comparison with MR imaging. MDCT might serve as an alternative imaging method in case of PM implantation.