Apropos of the recently published review on management of renal artery stenosis in the journal [1]. Diagnostic algorithm in the article shows that diagnosis is to be confirmed by Digital Subtraction Angiogram (DSA) even if findings are suggestive of renal artery stenosis (RAS) on computed tomograhy angio-graphy (CTA) or magnetic resonance angiography (MRA). In this context it is prudent to note that MRA is reported to have a sensitivity of 62.5% for RAS detection with 100% specificity [2], whereas sensitivity for CTA is known to be as high as 84.2% [2]. Authors have rightly pointed out radiation risks associated with CTA and DSA. In pediatric diagnostic imaging modalities, efforts are always made to reduce the radiation exposure by using radiation reduction protocols [3,4]. DSA unarguably remains gold standard for accurate diagnosis of RAS with a sensitivity and specificity of almost 100% [2]. However, it is the most invasive of all tests, requires anesthesia and involves radiation exposure. Thus, if CTA or MRA findings are suggestive of RAS then there should not be any need for DSA for diagnosis.

1. Villegas L, Cahill AM, Meyers K. Pediatric renovascular hypertension: Manifestations and management. Indian Pediatr. 2020;57:443-51.

2. Louis R, Levy-Erez D, Cahill AM, Meyers KE. Imaging studies in pediatric fibromuscular dysplasia (FMD): A single-center experience. Pediatr Nephrol. 2018;33: 1593-99.

3. Singhal M, Singh S, Gupta P, Sharma A, Khandelwal N, Burns JC. Computed tomography coronary angiography for evaluation of children with Kawasaki disease. Curr Probl Diagn Radiol. 2018;47:238-44.

4. Rashed M, Banka P, Barthur A, et al. Effects of dose reduction on diag-nostic image quality of coronary computed tomography angiography in children using a third-generation dual-source computed tomography scanner.　Am J Cardiol. 2018;122:1260-64.

Thank you for your interest in our review article [1]. The different imaging modalities were placed in the review to provide a comparison of the various tests and the associated risks. Although an MRA and CTA have been shown to have high sensitivity and specificity alongwith high quality images, renal artery stenosis can still be missed, specifically in patients with intra-renal arterial disease. The sensitivity and specificity of MRA is not as good in small children as it is in adults. This is the reason why DSA was selected for pediatric patients with a high pre-test probability of renovascular hypertension and patients with an associated genetic syndrome (see Web Table 1 [1]). We reiterate that we should suggest DSA to confirm a diagnosis of RAS, given the small vasculature within the pediatric population and its ability to guide potential timely intervention.

1. Villegas L, Cahill AM, Meyers K. Pediatric renovascular hypertension: Manifestations and management. Indian Pediatr. 2020;57:443-51.