[The Role of Cardiac MRI in the Diagnosis of Fabry Disease]

Abstract

Fabry disease is a rare X-linked metabolic disorder that is characterized by the accumulation of glycosphingolipids in various organs, resulting from the deficiency of alpha-galactosidase A. Cardiac involvement is relatively common; myocardial inflammation, left ventricular hypertrophy, and myocardial fibrosis secondary to abnormal lipid deposition in myocytes are often observed. Hence, the diagnosis of cardiac involvement is crucial for evaluating patient prognosis. Cardiac MRI is the standard technique for measuring the function, volume, and mass of the ventricles. It is also useful for myocardial tissue characterizations. The evaluation of native myocardial T1 values can facilitate early diagnosis of cardiac involvement, while measurements of left ventricular myocardial mass can be used to monitor treatment outcomes, in patients with Fabry disease. Consequently, cardiac MRI can provide useful information for diagnosing, monitoring, and treating patients with Fabry disease.

Fig. 1. A schematic diagram for Fabry disease.

Fabry disease is a genetic disease caused by an abnormality in the GLA gene that leads to a deficiency of alpha-galactosidase A and consequent accumulation of globotriaosylceramide (Gb3; GL3) in body organs. The management of symptoms and enzyme therapy may delay the progress of the disease. CMR = cardiac MRI, LGE = late gadolinium enhancement, LVH = left ventricular hypertrophy, TIA = transient ischemic attack

Fig. 2. Cardiac MR images showing cardiac manifestations of Fabry disease.

A. Concentric left ventricular hypertrophy can be seen in the cine image, with a left ventricular mass index of 80.5 g/m² [normal: 62 ± 7.5 g/m² (35)] and end diastolic interventricular septum thickness of 14 mm [normal: 5.3 ± 0.9 mm (36)]. B. A typical pattern of delayed enhancement of Fabry disease is seen (arrows); the manifestation does not affect the subendocardial area at the thickened inferolateral wall (7.6 mm). C. The T1 map shows an interventricular septum T1 value of 1169.3 ms (normal: 1219 ms), while the global T1, extracellular volume fraction are slightly elevated to 1227.3 ms and 27%, respectively. D. The T2 map shows an interventricular septum T2 value of 41 ms (normal: 40 ms), but the T2 of the inferolateral wall with delayed enhancement is elevated to 47 ms.