Late Iodine Enhancement and Extracellular Volume Fraction in Cardiac Amyloidosis by Computed Tomography

Abstract

vated at 43% (Figure C,D). Cardiac computed tomography (CT) was performed using a 256-detector row scanner. Equilibrium phase imaging was acquired 5 min after injection of 100 mL of iodine contrast agent (370 mgI/mL). The ECV was measured with the subtraction method using the precontrast and equilibrium phase images. Cardiac CT showed no coronary artery stenosis. Equilibrium phase imaging showed late iodine enhancement co-located with LGE (Figure E,F). The ECV by CT was 44%, as high as on CMR (Figure G,H). Per histopathology, the patient had A 72-year-old man was referred to hospital because of abnormal ECG, showing poor R wave progression in the precordial leads. Transthoracic echocardiography demonstrated concentric left ventricular hypertrophy, and speckle tracking showed an apical-sparing pattern. Cardiac magnetic resonance imaging (CMR) revealed late gadolinium enhancement (LGE) in the entire subendocardium, which was transmurally exhibited in the hypertrophic septum (Figure A,B). The extracellular volume fraction (ECV) by T1 mapping was remarkably ele-