Exploration of Interstitial Fibrosis in Chronic Kidney Disease by Diffusion‐Relaxation Correlation Spectrum MR Imaging: A Preliminary Study

• Published in: Journal of magnetic resonance imaging Vol. 58; no. 2; pp. 415 - 426
• Main Authors: Liu, Fang, Hu, Wentao, Sun, Yawen, Shen, Yiwei, Zhou, Wenyan, Dai, Yongming, Gu, Leyi, Zhang, Minfang, Zhou, Yan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.08.2023; Wiley Subscription Services, Inc
• Subjects: Adult; Biopsy; chronic kidney disease; Creatinine; Diffusion; Diffusion Magnetic Resonance Imaging - methods; diffusion‐relaxation correlated spectrum imaging; Diffusivity; Epidermal growth factor receptors; Female; Fibrosis; Field strength; Glomerular filtration rate; Humans; Kidney - diagnostic imaging; Kidney - pathology; Kidney diseases; Kidneys; Magnetic resonance imaging; Mathematical analysis; Medical imaging; Middle Aged; Neuroimaging; Noninvasive evaluation; Prospective Studies; Renal cortex; Renal Insufficiency, Chronic - diagnostic imaging; Renal Insufficiency, Chronic - pathology; renal interstitial fibrosis; Statistical analysis; Statistical tests; diffusion-relaxation correlated spectrum imaging; chronic kidney disease; renal interstitial fibrosis
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.28535

Background Renal interstitial fibrosis is one of the most common pathways in the progression of chronic kidney disease (CKD). Noninvasive evaluation of interstitial fibrosis would help monitoring CKD progression and prognosis prediction. Purpose To evaluate the severity of renal interstitial fibrosis by diffusion‐relaxation correlation spectrum imaging (DR‐CSI). Study Type Prospective. Subjects Forty patients with CKD and 10 healthy controls (average age 49.2 ± 14.8 years, 18 females). Field Strength/Sequence 3‐T, DR‐CSI with 36 axial spin‐echo echo‐planar diffusion‐weighted images (6 b‐values, 6 echo times). Assessment Interstitial fibrosis level (IFL) was assessed from biopsy results (IFL = 1, fibrosis percentage <25%, defined as mild; IFL = 2, 25%–50%, moderate; IFL = 3, >50%, severe). Estimated glomerular filtration rate (eGFR) was calculated using serum creatinine. The regions of interest included cortex for both kidneys. The diffusivity‐T2 spectrum was assessed considering three compartments (threshold: T2 30–40 msec, diffusivity 5–9 μm2/msec, according to visible peaks): A (low diffusivity, short T2), B (low diffusivity, long T2), and C (high diffusivity). Volume fractions Vi (i = A, B, C) were calculated. Statistical Tests Intra‐class coefficient (ICC, >0.6 as good) to assess inter‐reader agreement of DR‐CSI Vi. Spearman's correlation to assess relationship of Vi to IFL and eGFR. Receiver operating characteristic analyses with the area under the curve (AUC) to discriminate patients with moderate‐severe fibrosis from mild ones. Statistical significance criteria: P‐value <0.05. Results ICCs were good for all Vi. Correlations were found between IFL and VB (r = 0.424, significant) and VC (r = −0.400, significant), and between eGFR and VB (r = −0.303, P = 0.058) and VC (r = 0.487, significant). Regarding VB and VC, the AUCs were 0.903 and 0.824. Data Conclusion DR‐CSI help distinguish patients with moderate or severe renal interstitial fibrosis from mild ones. Evidence Level: 2 Technical Efficacy: Stage 2