title: Pilot Study of Renal Diffusion Tensor Imaging as a Correlate to Histopathology in Pediatric Renal Allografts.
abstract: 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.
  
  
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: 1 Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Ave, M-391, San Francisco, CA 94143-0628.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: 2 Department of Pediatric Nephrology, UCSF Benioff Children's Hospital, San Francisco, CA.
authors.forename: Marsha M
authors.initials: MM
authors.lastname: Lee
authors.affiliation: 3 GE Healthcare, Menlo Park, CA.
authors.forename: Pauline W
authors.initials: PW
authors.lastname: Worters
authors.affiliation: 1 Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Ave, M-391, San Francisco, CA 94143-0628.|4 Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA.
authors.forename: John D
authors.initials: JD
authors.lastname: MacKenzie
authors.affiliation: 5 Department of Pathology, University of California, San Francisco, San Francisco, CA.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Laszik
authors.affiliation: 1 Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Ave, M-391, San Francisco, CA 94143-0628.|4 Department of Radiology and Biomedical Imaging, UCSF Benioff Children's Hospital, San Francisco, CA.
authors.forename: Jesse L
authors.initials: JL
authors.lastname: Courtier
mesh_terms: D000293:Adolescent; D064591:Allografts / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D016030:Kidney Transplantation; D008297:Male; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome; D055815:Young Adult
keywords: MRI; biopsy; diffusion tensor imaging; histopathology; renal transplant