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Published on: February 2, 2022
Pilot Study of Renal Diffusion Tensor Imaging as a Correlate to Histopathology in Pediatric Renal Allografts
Yi Li1, Marsha M Lee2, Pauline W Worters3
11 Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Ave, M-391, San Francisco, CA 94143-0628.
Objective:
Fractional anisotropy (FA) is a measure of molecular motion obtained from diffusion tensor imaging (DTI). The objective of this study was to assess the use of FA as a noninvasive correlate of renal allograft histopathology.
Subjects And Methods:
Sixteen pediatric renal allograft recipients were imaged using DTI in a prospective study, between October 2014 and January 2016, before a same-day renal allograft biopsy. The Kendall tau correlation coefficient was used to assess the relationship between cortical and medullary FA values and several clinically important Banff renal allograft histopathology scores. The Mann-Whitney U test was also used to compare cortical and medullary FA values in the region of biopsy in patients whose biopsy results did and in those whose biopsy results did not change clinical management.
Results:
Medullary FA values had direct inverse correlation with several histopathology scores: tubulitis (designated "t" score in Banff pathologic classification, p < 0.04), interstitial inflammation (i score, p < 0.005), tubular atrophy (ct score, p < 0.002), and interstitial fibrosis (ci score, p < 0.007). Cortical FA values inversely correlated with peritubular capillaritis (ptc score, p < 0.02). Neither medullary nor cortical FA values correlated with glomerulitis (g score). At a b value of 800 s/mm2, medullary FA values of pediatric renal allograft recipients whose renal biopsies prompted a change in clinical management (mean ± SD at a b value of 800 s/mm2 = 0.262 ± 0.07; n = 9) were statistically different compared with the group whose biopsy results did not change clinical management (mean ± SD at a b value of 800 s/mm2 = 0.333 ± 0.06; n = 7) (p < 0.006).
Conclusion:
FA is a noninvasive correlate of several important renal allograft histopathology scores and a potential noninvasive method of assessing renal allograft health in pediatric allograft recipients.
Insights
Fractional anisotropy (FA) noninvasively correlates with renal allograft histopathology in children. This diffusion tensor imaging (DTI) measure may assess allograft health, guiding clinical management.
Area of Science:
- Nephrology
- Radiology
- Biomedical Imaging
Background:
- Renal allograft histopathology assessment is crucial for patient management.
- Noninvasive biomarkers are needed to monitor allograft health and guide treatment decisions.
Purpose of the Study:
- To evaluate Fractional Anisotropy (FA) derived from Diffusion Tensor Imaging (DTI) as a noninvasive biomarker for renal allograft histopathology.
- To correlate FA values with Banff classification scores in pediatric renal allograft recipients.
Main Methods:
- Prospective study of 16 pediatric renal allograft recipients undergoing DTI before biopsy.
- Kendall tau and Mann-Whitney U tests were used to analyze the relationship between FA values (cortical and medullary) and Banff scores.
- FA values were compared between patients whose biopsies changed and those whose biopsies did not change clinical management.
Main Results:
- Medullary FA showed inverse correlations with tubulitis, interstitial inflammation, tubular atrophy, and interstitial fibrosis scores.
- Cortical FA inversely correlated with peritubular capillaritis.
- Medullary FA values differed significantly between patients whose biopsies altered clinical management versus those whose did not.
Conclusions:
- FA serves as a noninvasive correlate of key renal allograft histopathology scores.
- FA shows potential as a noninvasive tool for assessing renal allograft health in pediatric recipients.
