Magnetic resonance imaging for the evaluation of rejection of a kidney allograft in the rat

Abstract Orthotopic DA (RT1 a) into Lewis (RT11) rat kidney allo‐grafts and control Lewis‐into‐Lewis grafts were assessed by magnetic resonance imaging (MRI) and per‐fusion measurement after intravenous injection of a superparamag‐netic contrast agent. MRI anatomical scores (range 1–6) and perfusion rates were compared with graft histology (rank of rejection score 1–6). Not only acute rejection, but also chronic events were monitored after acute rejection was prevented by daily cyclosporine (Sandimmune) treatment during the first 2 weeks after transplantation. In acute allograft rejection (n= 11), MRI scores reached the maximum value of 6 and perfusion rates were severely reduced within 5 days after transplantation; histology showed severe acute rejection (histologic score 5–6). In the chronic phase (100–130 days after transplantation), allografts (n= 5) manifested rejection (in histology cellular rejection and vessel changes), accompanied by MRI scores of around 2–3 and reduced perfusion rates. Both in the acute and chronic phases, the MRI anatomical score correlated significantly with the histological score (Spearman rank correlation coefficient rs 0.89, n= 30, P < 0.01), and perfusion rates correlated significantly with the MRI score or histological score (rs values between ‐0.60 and ‐0.87, n= 23, P < 0.01). It is concluded that MRI represents an interesting tool for assessing the anatomical and hemodynamical status of a kidney allograft in the acute and chronic phases after transplantation.

[1]  H. Hricak,et al.  Assessment of in situ renal transplant viability by 31P-MRS: experimental study in canines. , 1993, The American surgeon.

[2]  B. Rosen,et al.  Perfusion imaging with NMR contrast agents , 1990, Magnetic resonance in medicine.

[3]  V. Runge,et al.  Magnetic resonance imaging in ischemic injury after heart transplantation in rats. , 1991, The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation.

[4]  Pharmacology of cyclosporine (sandimmune). , 1990, Pharmacological reviews.

[5]  J. Borel.  Pharmacology of cyclosporine (sandimmune). IV. Pharmacological properties in vivo. , 1990, Pharmacological reviews.

[6]  H. Kantor,et al.  Heterotopic transplanted rat heart: a model for in vivo determination of phosphorus metabolites during ischemia and reperfusion , 1990, Magnetic resonance in medicine.

[7]  J. Shapiro,et al.  31P NUCLEAR MAGNETIC RESONANACE STUDY OF RENAL ALLOGRAFT REJECTION IN THE RAT , 1988, Transplantation.

[8]  B. Rosen,et al.  Dynamic imaging with lanthanide chelates in normal brain: Contrast due to magnetic susceptibility effects , 1988, Magnetic resonance in medicine.

[9]  D. W. Alderman,et al.  An efficient decoupler coil design which reduces heating in conductive samples in superconducting spectrometers , 1979 .

[10]  C. Fraser,et al.  Early phosphorus 31 nuclear magnetic resonance bioenergetic changes potentially predict rejection in heterotopic cardiac allografts. , 1990, The Journal of heart transplantation.

[11]  Noninvasive determination of regional cerebral blood flow in rats using dynamic imaging with Gd(DTPA) , 1991, Magnetic resonance in medicine.

[12]  L. Tiefenauer,et al.  Antibody-magnetite nanoparticles: in vitro characterization of a potential tumor-specific contrast agent for magnetic resonance imaging. , 1993, Bioconjugate chemistry.

[13]  J. Mintorovitch,et al.  Acute liver rejection: evaluation with cell-directed MR contrast agents in a rat transplantation model. , 1993, Radiology.

[14]  F. Lazeyras,et al.  Magnetic resonance spectroscopy for assessing myocardial rejection in the transplanted rat heart. , 1993, The Journal of Heart and Lung Transplantation.

[15]  B. Rosen,et al.  Pitfalls in MR measurement of tissue blood flow with intravascular tracers: Which mean transit time? , 1993, Magnetic resonance in medicine.