Myocardial Characterization Using Dual-Energy CT in Doxorubicin-Induced DCM: Comparison With CMR T1-Mapping and Histology in a Rabbit Model

• Published in: JACC. Cardiovascular imaging 2016-07, Vol.9 (7), p.836-845
• Main Authors: Hong, Yoo Jin, Kim, Tai Kyung, Hong, Donghyun, Park, Chul Hwan, Yoo, Sae Jong, Wickum, Mary Ellen, Hur, Jin, Lee, Hye-Jeong, Kim, Young Jin, Suh, Young Joo, Greiser, Andreas, Paek, Mun Young, Choi, Byoung Wook
• Format: Article
• Language: English
• Subjects: Animals; Antibiotics, Antineoplastic; Biopsy; Cardiomyopathy, Dilated - chemically induced; Cardiomyopathy, Dilated - diagnostic imaging; Cardiomyopathy, Dilated - metabolism; Cardiomyopathy, Dilated - pathology; Cardiotoxicity; Collagen - metabolism; Disease Models, Animal; Doxorubicin; Feasibility Studies; Fibrosis; Magnetic Resonance Imaging; Male; Myocardium - metabolism; Myocardium - pathology; Predictive Value of Tests; Rabbits; Time Factors; Tomography, X-Ray Computed
• ISSN: 1876-7591
• DOI: 10.1016/j.jcmg.2015.12.018

This study sought to evaluate whether patterns of myocardial change in doxorubicin-induced dilated cardiomyopathy determined using dual-energy computed tomography (CT) were similar to characterization by extracellular volume fraction (ECV) using cardiac magnetic resonance (CMR) T1-mapping and collagen volume fraction (CVF) measured using histology. Anthracycline chemoagents are effective against a wide range of malignant conditions. However, cardiotoxicity is a well-known adverse effect of these drugs. Dual-energy CT could be as useful as magnetic resonance (MR) to evaluate myocardial change in anthracycline-induced cardiotoxicity. A dilated cardiomyopathy rabbit model was generated by injecting 11 adult New Zealand rabbits with 1.0 mg/kg of doxorubicin twice weekly for 16 weeks. Contrast-enhanced dual-energy CT and pre-contrast and post-contrast T1-mapping CMR using a prototype modified Look-Locker inversion recovery on a clinical 3-T scanner were performed on 15 rabbits, including 4 control animals, to calculate ECV at baseline, and at 6, 12, and 16 weeks after doxorubicin administration. The mean ECV values (%) on CT and CMR at 6, 12, and 16 weeks after modeling were significantly higher than those measured at baseline (CT ECV: 35.3%, 41.9%, 42.1% vs. 28.5%; MR ECV: 32.6%, 35.8%, 41.3% vs. 28.8%, respectively; all p < 0.001). CT ECV and MR ECV values were well correlated (r = 0.888; p < 0.001). Both were well correlated with CVF on histology (CT ECV vs. CVF, r = 0.925, p < 0.001 and MR ECV vs. CVF, r = 0.961, p < 0.001, respectively). Dual-energy CT ECV correlated well with CMR and histology. Dual-energy CT is useful for characterizing doxorubicin-induced cardiomyopathy by measuring ECV fraction; however, further technical improvements are desirable to lower motion artifact and improve image quality of the iodine map.