How I do it: Renal Non-Enhanced MR Angiography (syngo NATIVE TrueFISP) in Pediatric Patients

The association between nephrogenic systemic fibrosis (NSF) and gadolinium-based (Gd) contrast agents has generated an active interest in the development and optimization of Non-Enhanced MR Angiography (NE-MRA) techniques. These techniques rely on physiologic processes, in conjunction with careful application of radio-frequency (RF) and gradient pulses, for maximizing the contrast between the desired vasculature and the rest of background. syngo NATIVE TrueFISP was developed to optimize the conspicuity of renal arteries without administration of contrast, and is ideal to assess renal arteries in patients following kidney transplantation, impaired renal function, allergy to gadolinium based contrast agents, pregnant women, and neonates*. Renal NEMRA aims to provide robust and high resolution MRA with maximal arterial signal and suppression of static tissue signal and venous flow. Figure 1 summarizes the principle of this sequence [1]. It utilizes 3D TrueFISP readout for bright-blood imaging. Background tissues are suppressed using one or more selective inversion pulses. To minimize respiratory motion-induced artifacts, the data acquisition has typically been synchronized to the respiratory cycle with respiratory gating using cross-pair navigator. A new alternative technique involves the use of respiratory bellows for respiratory gating because it is easier to setup than cross-pair navigator, and it also provides better and consistent image quality.