[Evaluation of kidney oxygen bioavailability in acute renal failure by blood oxygen level dependent magnetic resonance imaging].
To assess the kidney oxygen bioavailability in acute renal failure using blood oxygen level dependent (BOLD) magnetic resonance (MR) imaging.



Twenty-one patients with acute renal failure, including 18 patients with oliguric renal failure, 1 nonoliguric acute renal failure and 2 functional renal failure were enrolled in the study; 20 healthy subjects served as controls. All subjects received renal functional MR examination. BOLD MR imaging with 16 gradient-recalled-echoes on a 1.5-T scanner were performed. R2(*)(1/sec) values of the cortex and medulla and R2(*) ratio of the medulla to cortex (R2(*) ratio of M/C) of the renal were recorded respectively.



The R2(*) values of the medulla was higher than those of the cortex in controls (17.64 +/-1.86/sec vs 13.73 +/-0.49/sec, P<0.00). The R2(*) ratio of M/C in controls was 1.28 +/-0.06. The R2(*) values of the medulla (13.31 +/-4.28/sec) and cortex (12.25 +/-2.41/sec) and the R2(* ) ratio of M/C (1.01 +/-0.25) in oliguric renal failure were lower than those in controls (P <0.05). Patients with functional renal failure and nonoliguric acute renal failure had higher R2(*) values in cortex and medulla and higher R2(*) ratio of M/C than those of controls.



BOLD MRI demonstrates that decreased R2(*) values of cortex and medulla suggest lower oxygen bioavailability in acute renal failure and decreased R2(*)ratio of M/C suggests the disappearance of a steep cortico-medullary gradient of oxygen.
Xiao
Wen-bo
WB
Department of Radiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
Wang
Qi-dong
QD
Xu
Jing-jing
JJ
Han
Fei
F
Zhang
Min-ming
MM
D058186:Acute Kidney Injury / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D000328:Adult; D001682:Biological Availability; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000503:physiopathology; D007677:Kidney Function Tests / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood* / Q000378:metabolism*
D010100:Oxygen