Minming Zhang MD,PhD, Presenter: Nothing to Disclose

Menbo Xiao, Abstract Co-Author: Nothing to Disclose

Qidong Wang, Abstract Co-Author: Nothing to Disclose

Jianghua Chen, Abstract Co-Author: Nothing to Disclose

Guang Cao PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the oxygenation state of the kidneys in normal subjects and patients with renal transplants, and to determine the feasibility of using blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging to differentiate between acute rejection and normal function.

BOLD MR imaging was performed in 8 healthy volunteers and 50 renal-transplant patients during 2-3 weeks posttransplantation. Of the renal-transplant patients, 42 patients had clinically normal function transplants, and 8 patients had biopsy-proved acute rejection. Color R2* maps were calculated and mean R2*(1/sec) values for the cortex and medulla of the kidneys were obtained, respectively. Statistical analysis was performed by using Student t tests. Threshold R2* values were identified to discriminate between transplanted kidneys with acute rejection and those with normal function.

In normal subjects, R2* values were significantly higher in the medulla (20.06±1.86/sec) than in the cortex (13.12±0.49/sec)(P < 0.05). In normal functioning transplants, R2* values of the medulla (29.02±8.70/sec) were also higher than that of the cortex (23.94±7.26/sec) (P < 0.05). The differences of the R2* values of the medulla and cortex between the normal subjects and renal transplants were significant. Furthermore, R2* values for the medulla were significantly lower in the acute rejection patients (18.41±3.23/sec) than in the normal function grafts (29.02±8.70/sec) (P = 0.01). Acute rejection could be differentiated from normal function in all cases by using a threshold R2* value of 22/sec.

The higher R2* values of the medullary and cortex in normally functioning transplants indicated a higher oxygen consumption in those patients than that in healthy subjects, which might because that the patients in our group were in the stage of temporal high perfusion during the early posttransplant period. Greatly decreased R2* value in grafts (<22/sec) were associated with a risk of acute rejection episodes.

BOLD MR imaging might be useful to identify intra-renal oxygenation and to differentiate between acute rejection and normal function.

Zhang, M, Xiao, M, Wang, Q, Chen, J, Cao, G, Evaluation of Intra-renal Oxygenation of Kidneys in Normal Subjects and Patients with Renal Transplant by BOLD MRI.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4432504.html