Fabry's disease is an X-linked inborn error of glycosphingolipid catabolism caused by deficient activity of α-galactosidase A, a lysosomal exoglycosidase.^1,2 In males with the classic form of the disease, there is little if any α-galactosidase A activity. As a result, undegraded glycosphingolipids accumulate, particularly in the vascular endothelium. These deposits cause the characteristic angiokeratomas, acroparesthesias, hypohidrosis, and corneal opacities of Fabry's disease. Death in early adulthood in affected persons may be due to vascular disease of the heart, kidney, or brain. These abnormalities are absent in males with the cardiac variant of the disease. Those with the cardiac variant typically present with a mild, late-onset disorder that is primarily limited to the heart, and there is no involvement of the vascular endothelium.^1-3 With advancing age, however, cardiac involvement progresses and leads to death.⁴ All of the previously described patients with the cardiac variant of Fabry's disease had mutations in the α-galactosidase A gene that encoded sufficient residual enzymatic activity to preclude the classic phenotype.^1-3,5,6

Transcatheter aortic valve replacement (TAVR) is a minimally invasive alternative to conventional aortic valve replacement in symptomatic patients with severe aortic stenosis and contraindications to surgery. The procedure has shown to improve patient’s quality of life and prolong short- and mid-term survival in high-risk individuals, becoming a widely accepted therapeutic option which has been integrated into current clinical guidelines for the management of valvular heart disease. Nevertheless, not every patient at high-risk for surgery is a good candidate for TAVR. Besides clinical selection, which is usually established by the Heart Team, certain technical and anatomic criteria must be met as, unlike in surgical valve replacement, annular sizing is not performed under direct surgical evaluation but on the basis of non-invasive imaging findings. Present consensus document was outlined by a working group of researchers from the European Society of Cardiovascular Radiology (ESCR) and aims to provide guidance on the utilisation of CT and MR imaging prior to TAVR. Particular relevance is given to the technical requirements and standardisation of the scanning protocols which have to be tailored to the remarkable variability of the scanners currently utilised in clinical practice; recommendations regarding all required pre-procedural measurements and medical reporting standardisation have been also outlined, in order to ensure quality and consistency of reported data and terminology. Key Points • To provide a reference document for CT and MR acquisition techniques, taking into account the significant technological variation of available scanners. • To review all relevant measurements that are required and define a step-by-step guided approach for the measurements of different structures implicated in the procedure. • To propose a CT/MR reporting template to assist in consistent communication between various sites and specialists involved in the procedural planning.