Features non-enhanced magnetic resonance imaging in the selection of candidates for radiofrequency denervation of the renal arteries

Abstract

Aim. To assess the diagnostic ability of a non-contrast MR-angiography (MRA) of renal arteries (RA) during selection of patients for percutaneous denervation of renal arteries.
Methods and Materials. The study included 23 patients with refractory hypertension aged 31 to 75 years. All candidates to the denervation was performed duplex scanning of the renal arteries (Doppler ultrasound), non-enhanced MRA and abdominal aortography selective angiography. Magnetic resonance imaging (MRI) was performed superconducting MRI "Initial Achieva" company Philips (Netherlands) with a magnetic field of 3 Tesla, the system TX. The study was performed with synchronized ECG and respiration. The estimation of the following parameters:
– аvailability of additional renal arteries;
– renal arteries diameter;
– length of the renal artery (from the mouth to the bifurcation);
– presence of significant stenosis of the renal arteries.
Results. Contraindications to denervation were identified in 6 cases (28.5%): 2 patients had significant stenosis of the renal arteries and 4 patients had double blood supply to the kidneys with the small diameter in the additional arteries. Denervation was performed in 15 cases (71,4%), including 3 patients with hemodynamically nonsignificant stenosis. In 2 patients (9.5%) with severe abdominal obesity quality of the MR images did not allow to reliably determine the anatomy of the renal arteries. In all cases the results of MRA were confirmed during interventional aortography. A significant correlation of the results of MRA and aortography in determining the renal arteries size and presence of stenosis was found.
Conclusion. The non-contrast MRA can be applied during complex examination of patients with resistant hypertension before renal arteries denervation procedure.