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©The Author(s) 2026. Published by Baishideng Publishing Group Inc. All rights reserved.
Apparent diffusion coefficient of kidneys with non-contrast magnetic resonance angiography for functional and anatomical assessment in renal artery stenosis
Hira Lal, Surabhi Agarwal, Kaushik Ponmalai, Raghunandan Prasad, Dharmendra S Bhadauria, Sanjay Gambhir, Swagata Mandal, Sandeep Kumar, Priyank Yadav, Pinky Jowel
Hira Lal, Surabhi Agarwal, Kaushik Ponmalai, Raghunandan Prasad, Swagata Mandal, Sandeep Kumar, Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, Uttar Pradesh, India
Dharmendra S Bhadauria, Department of Nephrology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, Uttar Pradesh, India
Sanjay Gambhir, Department of Nuclear Medicine, Sanjay Gandhi Postgraduate Institute of Nuclear Medicine, Lucknow 226014, Uttar Pradesh, India
Priyank Yadav, Department of Urology and Renal Transplantation, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, Uttar Pradesh, India
Pinky Jowel, Department of Health and Family Welfare, National Health Mission, Government of Uttar Pradesh, Lucknow 226001, Uttar Pradesh, India
Author contributions: Lal H, Agarwal A, Prasad R, Bhadauria D, Gambhir S, Yadav P designed and coordinated the study; Lal H, Agarwal S, Mandal S, Kumar S performed the examinations, acquired and analyzed data; Lal H, Ponmalai K, Prasad R, Jowel P interpreted the data; Agarwal S, Yadav P wrote the manuscript; Statistical analysis was performed by Agarwal S, Yadav P, Singh A; all authors approved the final version of the article.
Institutional review board statement: The study was reviewed and approved by the institutional review board of SGPGIMS, Lucknow, India (IEC code: 2018-110-MD-EXP; PGI/BE/424/2018).
Informed consent statement: All study participants provided written consent prior to study enrollment.
Conflict-of-interest statement: The authors of this manuscript have no conflicts of interest to disclose.
Data sharing statement: There is no additional data available.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Hira Lal, Professor, Department of Radiology, Sanjay Gandhi Postgra
duate Institute of Medical Sciences, Raibareli Road, Lucknow 226014, Uttar Pradesh, India.
hiralal2007@yahoo.co.in
Received: April 2, 2025
Revised: May 25, 2025
Accepted: August 20, 2025
Published online: March 20, 2026
Processing time: 316 Days and 0.8 Hours
BACKGROUND
Renal artery stenosis (RAS) is a vascular disorder linked to secondary hypertension, chronic kidney disease, and renal failure due to interstitial fibrosis. Early diagnosis is crucial as RAS-induced hypertension responds well to angioplasty. Non-invasive imaging techniques, including non-contrast magnetic resonance angiography (NC-MRA), help assess RAS without contrast-related risks. Diffusion-weighted MR imaging (DW-MRI) has emerged as a promising method for evaluating kidney function by measuring the apparent diffusion coefficient (ADC), which correlates with renal pathology.
AIM
To compare ADC values in hypertensive, RAS, and healthy kidneys, assess the correlation between ADC and stenosis severity, and evaluate its relationship with split glomerular filtration rate (GFR).
METHODS
This prospective observational study which included 86 patients with suspected RAS and twenty normal healthy controls underwent NC-MRA on a 3T-MR-Scanner followed by DW-MRI at b values of 0 and 1000 seconds/mm2 in the transverse plane. ADC maps were created using Functool. ADC values were measured in the cortex and medulla of each kidney's upper, middle, and lower pole, and the average ADC (ADCavg) for cortex and medulla calculated. In patients with RAS, degree of stenosis (DOS) was calculated on NC-MRA. The ADC of 212 kidneys was compared, and the relationship between DOS and ADC was established. In addition, split GFR was calculated in 30 kidneys using 99mTc-DTPA, and correlated with ADC value. The ADC values of kidneys with and without RAS were compared using the Student’s t-test. The correlation between ADC and stenosis severity was assessed by Spearman’s test, while the relationship between ADC and split GFR was evaluated using Pearson’s test. A Pvalue < 0.05 was considered statistically significant.
RESULTS
RAS was detected in 58 of 86 (67.44%) hypertensive patients (81 of 172 kidneys), and the ADCavg (P = 0.044) was significantly lower in RAS kidneys than in kidneys with normal arteries and essential hypertension and healthy controls.
CONCLUSION
DW-MRI can be a useful non-invasive technique to estimate the kidney’s functional status in RAS patients. It can be used as a complementary assessment tool with NC-MRA to triage patients in need of interventional management.
Core Tip: Diffusion-weighted magnetic resonance imaging (DW-MRI) provides a non-invasive method to assess renal function in patients with renal artery stenosis (RAS). This study demonstrates that the apparent diffusion coefficient is significantly lower in RAS-affected kidneys, correlating with stenosis severity and split glomerular filtration rate. DW-MRI, in combination with non-contrast magnetic resonance angiography, offers a promising tool for early detection and triage of RAS patients, potentially guiding timely intervention and improving clinical outcomes.
