1348640 - Myocardial Viability Assessment with a Novel 0.55T Scanner Compared to Conventional 1.5T Scanner

A 64-year-old male was admitted with new acute systolic heart failure with echocardiogram demonstrating global left ventricular (LV) dysfunction with an ejection fraction (EF) of 25%. The clinical course was complicated by respiratory failure, cirrhosis, pericardial effusion, acute kidney injury, and stroke. His cardiac catheterization showed 70% mid left anterior descending (LAD) stenosis as well as 60% proximal right coronary artery (RCA) stenosis. Once medically stabilized, the patient was referred for cardiovascular magnetic resonance (CMR) to assess myocardial viability.

Diagnostic Techniques and Their Most Important Findings:

A comprehensive CMR exam was performed on a 1.5T scanner (MAGNETOM Sola, Siemens Healthcare, Erlangen, Germany) including real-time steady-state free precession (SSFP) cine imaging, T1 mapping, and free-breathing motion corrected late gadolinium enhancement (LGE) imaging. The study revealed severe systolic dysfunction LVEF 24%, and a large pericardial effusion. LGE imaging demonstrated prominent septal midwall non-ischemic fibrosis [Figure 1A]. Six months post discharge, the patient volunteered to undergo a CMR scan on a 0.55T research scanner (MAGNETOM Free.Max, Siemens Healthcare, Erlangen, Germany). The imaging protocol consisted of prototype cardiac sequences to match the original clinical scan. Volumetric and function measurements on the 0.55T system revealed increased LVEF to 39% in relation to improved clinical status. LGE imaging performed well on the 0.55T scanner demonstrating septal non-ischemic fibrosis [Figure 1B].  

Learning Points from this Case:

Non-ischemic LV scar has been previously shown to be an independent risk factor associated with cardiomyopathy, death and malignant arrhythmic events, irrespective of total LGE burden (1,2). Previous studies have demonstrated that SSFP cine image quality and ischemic LGE assessment are comparable between most widely used 1.5T and 0.55T CMR scanners (3,4). To our knowledge, this is the first case to show comparable non-ischemic LGE image quality on a novel 0.55T scanner and a conventional 1.5T scanner. This work further highlights the potential use of 0.55T scanners for the evaluation of other cardiovascular pathologies with a spectrum of LGE patterns and marks another step toward the integration of lower field CMR imaging for the evaluation of non-ischemic cardiomyopathy in clinical practice.