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

JACC Cardiovasc Imaging. 2016 Jul;9(7):836-845. doi: 10.1016/j.jcmg.2015.12.018. Epub 2016 May 25.

Abstract

Objectives: 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.

Background: 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.

Methods: 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.

Results: 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).

Conclusions: 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.

Keywords: cardiac imaging techniques; cardiomyopathy; dual-energy scanned projection; magnetic resonance imaging; mapping; radiography.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic*
  • Artifacts
  • 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*

Substances

  • Antibiotics, Antineoplastic
  • Doxorubicin
  • Collagen