Iodine accumulation of the liver in patients treated with amiodarone can be unmasked using material decomposition from multiphase spectral-detector CT

Zielsetzung Amiodarone accumulates in liver, where it increases x-ray-attenuation by its iodine-content. We evaluated liver-attenuation in patients treated and not-treated with amiodarone using true-non-contrast (TNC) and virtual-non-contrast (VNC) images acquired with spectral-detector-CT (SDCT).

Material und Methoden 142 patients, of which 21 have been treated with amiodarone, receiving SDCT-examinations (unenhanced-chest [TNC], CT-angiography of chest and abdomen [CTA-Chest, CTA-Abdomen]) for transcatheter-aortic-valve-replacement (TAVR)-planning were included. TNC, CTA-Chest, CTA-Abdomen, and corresponding VNC-images (VNC-Chest, VNC-Abdomen) were reconstructed. Image-analysis was conducted using ROI-based measurements of mean-attenuation (HU). Liver-attenuation-index (LAI) was calculated as difference between liver- and spleen-attenuation.

Ergebnisse Liver-attenuation and LAI derived from TNC-images of patients receiving amiodarone were higher (63.1±9.8HU versus 58.1±8.6HU, p=0.04; 16.8±7.9HU versus 9.7±8.1HU, p<0.001). Contrary to TNC, liver-attenuation and LAI were not higher in amiodarone patients in VNC-Chest (liver-attenuation, 56.3±8.3HU versus 55.3±5.8HU, p=0.35; LAI, 7.5±8.5HU versus 7.5±6.9HU, p=0.50) and in VNC-Abdomen (liver-attenuation, 59.2±6.4HU versus 58.7±5.8HU, p=0.62; LAI, 8.5±6.5HU versus 6.5±6.7HU, p=0.10). In patients untreated with amiodarone, VNC accurately subtracted iodine and depicted similar attenuation compared to TNC.

Schlußfolgerungen Patients treated with amiodarone showed higher liver-attenuation in TNC. In contrast, VNC revealed comparable liver-attenuation in patients treated and untreated with amiodarone indicating that VNC accurately subtracted hepatic amiodarone-deposits in line to contrast-agent related iodine-uptake.