Quantitative MR measures of intrarenal perfusion in the assessment of transplanted kidneys: initial experience.
OBJECTIVE
The purpose of this study was to evaluate prospectively a gadolinium-based perfusion technique for intrarenal blood flow in transplanted kidneys and to determine if magnetic resonance imaging (MRI) measurements of intrarenal perfusion could be used to differentiate between normal-functioning kidney allografts and allografts with acute tubular necrosis (ATN) or acute rejection.


METHODS
Twenty-one subjects were enrolled within 4 months of receiving a kidney transplant. A biopsy was performed on subjects to diagnose each allograft as having either ATN or acute rejection. A group of subjects with normal functioning transplants was also enrolled in our study. MRI perfusion images were acquired on a 1.5 T MRI system within 48 hours after biopsy using an echo planar, T2*-weighted sequence, and an injection of gadodiamide contrast agent administered at a dose of 0.1 mmol/kg. Scan parameters were: repetition time/echo time/flip = 1000 ms/30 ms/60 degrees , field of view = 340 x 340 mm, matrix = 128 x 64, slice thickness = 10 mm, and temporal resolution = 1.0 seconds. Cortical and medullary blood flow values were calculated.


RESULTS
Medullary blood flow values were significantly (P = .02) lower in allografts undergoing acute rejection (121 +/- 41 mL/100 g/min) compared to normal-functioning allografts (221 +/- 96 mL/100 g/min) and those with ATN (247 +/- 124 mL/100 g/min). Cortical blood flow values were also significantly (P = .03) reduced in allografts with acute rejection (243 +/- 116 mL/100 g/min) compared to those with normal function (413 +/- 116 mL/100 g/min).


CONCLUSIONS
Preliminary results indicate that MRI perfusion techniques may provide a means of determining noninvasively the viability of renal allografts, potentially alleviating the need for biopsy in some patients.
Wentland
Andrew L
AL
Department of Radiology, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, Madison, WI 53705-2275, USA.
Sadowski
Elizabeth A
EA
Djamali
Arjang
A
Grist
Thomas M
TM
Becker
Bryan N
BN
Fain
Sean B
SB
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007668:Kidney / Q000098:blood supply* / Q000503:physiopathology*; D016030:Kidney Transplantation / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging; D010865:Pilot Projects; D012039:Regional Blood Flow; D055815:Young Adult
C064925:gadodiamide; D019786:Gadolinium DTPA