Cardiac MR elastography for quantitative assessment of elevated myocardial stiffness in cardiac amyloidosis

J Magn Reson Imaging. 2017 Nov;46(5):1361-1367. doi: 10.1002/jmri.25678. Epub 2017 Feb 25.

Abstract

Purpose: To evaluate if cardiac magnetic resonance elastography (MRE) can measure increased stiffness in patients with cardiac amyloidosis. Myocardial tissue stiffness plays an important role in cardiac function. A noninvasive quantitative imaging technique capable of measuring myocardial stiffness could aid in disease diagnosis, therapy monitoring, and disease prognostic strategies. We recently developed a high-frequency cardiac MRE technique capable of making noninvasive stiffness measurements.

Materials and methods: In all, 16 volunteers and 22 patients with cardiac amyloidosis were enrolled in this study after Institutional Review Board approval and obtaining formal written consent. All subjects were imaged head-first in the supine position in a 1.5T closed-bore MR imager. 3D MRE was performed using 5 mm isotropic resolution oblique short-axis slices and a vibration frequency of 140 Hz to obtain global quantitative in vivo left ventricular stiffness measurements. The median stiffness was compared between the two cohorts. An octahedral shear strain signal-to-noise ratio (OSS-SNR) threshold of 1.17 was used to exclude exams with insufficient motion amplitude.

Results: Five volunteers and six patients had to be excluded from the study because they fell below the 1.17 OSS-SNR threshold. The myocardial stiffness of cardiac amyloid patients (median: 11.4 kPa, min: 9.2, max: 15.7) was significantly higher (P = 0.0008) than normal controls (median: 8.2 kPa, min: 7.2, max: 11.8).

Conclusion: This study demonstrates the feasibility of 3D high-frequency cardiac MRE as a contrast-agent-free diagnostic imaging technique for cardiac amyloidosis.

Level of evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1361-1367.

Keywords: #cardiac MRE; #cardiac amyloidosis; magnetic resonance elastography; myocardial stiffness; quantitative stiffness imaging.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amyloidosis / diagnostic imaging*
  • Amyloidosis / pathology
  • Case-Control Studies
  • Contrast Media
  • Echocardiography*
  • Elastic Modulus
  • Elasticity Imaging Techniques*
  • Female
  • Heart / diagnostic imaging*
  • Heart Ventricles / diagnostic imaging*
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Myocardium / pathology*
  • Patient Positioning

Substances

  • Contrast Media