Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Karolinska Institutet Swedish Heart and Lung foundation
Introduction
Fabry disease (FD) is a lysosomal disease that causes accumulation of sphingolipids, which untreated may leadto hypertrophic cardiomyopathyand renal failure. Cardiovascular magnetic resonance imaging (CMR) can detect sphingolipid accumulationin the heart, using native T1 mapping. The kidneys are often visible in clinically acquired native T1 maps, however it is currently unknown if clinically acquired native T1 maps of the heart also can be used to detect sphingolipid accumulation in the kidneysin FD patients.
Purpose
To evaluate if clinically acquired native T1 maps using CMR can be used to detect sphingolipid accumulation in the kidneysin FD patients.
Methods
FD patients (n = 18, 41 ± 10 years, 44 % male) and healthy volunteers (n = 41, 26 ± 5 years, 49 % male) were retrospectively enrolled. Native T1 maps were acquired with a 1.5 T scanner (Magnetom Aera, Siemens Healthineers, Erlangen, Germany) usinga modified look locker inversion recovery (MOLLI) sequence with a 5s(3s)3s sampling scheme (Siemens WIP 1041). The native T1 maps were analysed using Segment (Medviso AB, Lund, Sweden). Native T1 values were measured by manually delineating regions of interest (ROI), conservatively placed with a minimum gap of 1 pixel between adjacent structures, in the renal cortex, renal medulla, myocardium, spleen, blood, and liver. Renal cortex ROIs were delineated in all slices where the renal cortex was visible and averaged across all slices. Renal medulla, spleen, and liver ROIs were drawn in the slice where most parenchyma was visible. Endo- and epicardial borders were delineated in all slices of the myocardium and averaged across all slices. Blood ROIs were placed in the midventricular slice, Figure 1.
Results
There were no differences in native T1 values between the patients and the healthy volunteers in the renal cortex (1034 ± 88 vs 1038 ± 51 ms, p = 0.89), blood (1632 ± 123 vs 1600 ± 104 ms, p = 0.94), spleen (1143 ± 45 vs 1134 ± 77 ms, p = 0.64) or liver (569 ± 49 vs 576 ± 45 ms, p = 0.57), and did not change when analysed with regards to sex, Figure 2. Native T1-values were lower in the myocardium of the patients compared to the healthy volunteers (937 ± 53 vs 1019 ± 35 ms, p = 0.01), and higher in the renal medulla (1635 ± 144 vs 1523 ± 70 ms, p = 0.01).
Conclusions
Compared to healthy volunteers, patients with FD and myocardial involvement have no differences in native T1 of the renal cortex. FD patients have higher native T1 in the renal medulla, which cannot be explained by differences in blood native T1. The findings suggest that clinically acquired native T1-maps cannot be used to detect sphingolipid accumulation in the renal cortex in FD patients.