title: New Magnetic Resonance Imaging Index for Renal Fibrosis Assessment: A Comparison between Diffusion-Weighted Imaging and T1 Mapping with Histological Validation.
abstract: A need exists to noninvasively assess renal interstitial fibrosis, a common process to all kidney diseases and predictive of renal prognosis. In this translational study, Magnetic Resonance Imaging (MRI) T1 mapping and a new segmented Diffusion-Weighted Imaging (DWI) technique, for Apparent Diffusion Coefficient (ADC), were first compared to renal fibrosis in two well-controlled animal models to assess detection limits. Validation against biopsy was then performed in 33 kidney allograft recipients (KARs). Predictive MRI indices, ΔT1 and ΔADC (defined as the cortico-medullary differences), were compared to histology. In rats, both T1 and ADC correlated well with fibrosis and inflammation showing a difference between normal and diseased kidneys. In KARs, MRI indices were not sensitive to interstitial inflammation. By contrast, ΔADC outperformed ΔT1 with a stronger negative correlation to fibrosis (R(2) = 0.64 against R(2) = 0.29 p < 0.001). ΔADC tends to negative values in KARs harboring cortical fibrosis of more than 40%. Using a discriminant analysis method, the ΔADC, as a marker to detect such level of fibrosis or higher, led to a specificity and sensitivity of 100% and 71%, respectively. This new index has potential for noninvasive assessment of fibrosis in the clinical setting.
authors.affiliation: Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: I
authors.initials: I
authors.lastname: Friedli
authors.affiliation: Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: L A
authors.initials: LA
authors.lastname: Crowe
authors.affiliation: Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Berchtold
authors.affiliation: Division of Pathology, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Moll
authors.affiliation: Divisions of Nephrology and Transplantation, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Hadaya
authors.affiliation: Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: de Perrot
authors.affiliation: Division of Cell Physiology and Metabolism, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Vesin
authors.affiliation: Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland.
authors.forename: P-Y
authors.initials: PY
authors.lastname: Martin
authors.affiliation: Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: de Seigneux
authors.affiliation: Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland.
authors.forename: J-P
authors.initials: JP
authors.lastname: Vallée
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D005260:Female; D005355:Fibrosis / Q000175:diagnosis* / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007674:Kidney Diseases / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D051381:Rats; D012680:Sensitivity and Specificity