High Spatial Resolution Cardiovascular Magnetic Resonance at 7.0 Tesla in Patients with Hypertrophic Cardiomyopathy – First Experiences: Lesson Learned from 7.0 Tesla

Abstract

BackgroundCardiovascular Magnetic Resonance (CMR) provides valuable information in patients with hypertrophic cardiomyopathy (HCM) based on myocardial tissue differentiation and the detection of small morphological details. CMR at 7.0T improves spatial resolution versus today’s clinical protocols. This capability is as yet untapped in HCM patients. We aimed to examine the feasibility of CMR at 7.0T in HCM patients and to demonstrate its capability for the visualization of subtle morphological details.MethodsWe screened 131 patients with HCM. 13 patients (9 males, 56 ±31 years) and 13 healthy age- and gender-matched subjects (9 males, 55 ±31years) underwent CMR at 7.0T and 3.0T (Siemens, Erlangen, Germany). For the assessment of cardiac function and morphology, 2D CINE imaging was performed (voxel size at 7.0T: (1.4x1.4x2.5) mm3 and (1.4x1.4x4.0) mm3; at 3.0T: (1.8x1.8x6.0) mm3). Late gadolinium enhancement (LGE) was performed at 3.0T for detection of fibrosis.ResultsAll scans were successful and evaluable. At 3.0T, quantification of the left ventricle (LV) showed similar results in short axis view vs. the biplane approach (LVEDV, LVESV, LVMASS, LVEF) (p = 0.286; p = 0.534; p = 0.155; p = 0.131). The LV-parameters obtained at 7.0T where in accordance with the 3.0T data (pLVEDV = 0.110; pLVESV = 0.091; pLVMASS = 0.131; pLVEF = 0.182). LGE was detectable in 12/13 (92%) of the HCM patients. High spatial resolution CINE imaging at 7.0T revealed hyperintense regions, identifying myocardial crypts in 7/13 (54%) of the HCM patients. All crypts were located in the LGE-positive regions. The crypts were not detectable at 3.0T using a clinical protocol.ConclusionsCMR at 7.0T is feasible in patients with HCM. High spatial resolution gradient echo 2D CINE imaging at 7.0T allowed the detection of subtle morphological details in regions of extended hypertrophy and LGE.

Myocardial Effective Transverse Relaxation Time T 2 * is Elevated in Hypertrophic Cardiomyopathy: A 7.0 T Magnetic Resonance Imaging Study

“…All HCM patients included in the study had previously undergone a clinical MRI exam including LGE imaging for detection of myocardial fibrosis 27 . For this purpose a 3.0 T MR system (Magnetom Verio, Siemens, Erlangen, Germany) was employed using a 32-channel RF receive array.…”

“…The overall distribution of septal T 2 * was analyzed using the histogram of the relative frequencies of T 2 * for all septal voxels in all subjects within the respective group. Evaluation of LV-morphology was described recently 27 .…”

Optimal site selection and image fusion guidance technology to facilitate cardiac resynchronization therapy

“…CMR remains the pre-eminent imaging modality for assessing both tissue characterization and mechanical activation, and the increasing experience with ultrahigh field CMR will inevitably result in improved image quality [152,153]]. Greater spatial resolution will allow detailed visualization of the entire coronary venous tree allowing pre-procedural planning to be performed entirely from one, non-ionizing imaging modality.…”

7T: Physics, safety, and potential clinical applications

“…On the cardiac UHF MRI applications side, a recent study investigated high spatial resolution cardiac MRI in 13 patients with hypertrophic cardiomyopathy . The imaging protocol allowed for intraindividual comparison of patients imaged with 3T and 7T MR systems.…”

“…The imaging protocol allowed for intraindividual comparison of patients imaged with 3T and 7T MR systems. The authors of this initial study concluded that 7T cardiac MRI is feasible in patients with hypertrophic cardiomyopathy, allowing for the detection of subtle morphological details in regions of extended hypertrophy and late gadolinium enhancement …”