Using functional magnetic resonance imaging to evaluate an acute allograft rejection model in rats.

Abstract

PURPOSE:

To assess the longitudinal changes of allograft pathophysiology by intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) MRI in a rat model of acute renal allograft rejection.

MATERIALS AND METHODS:

Acute rejection (AR) was induced by transplantation of Dark Agouti donor kidneys into Lewis recipients (n = 18). A Lewis-Lewis rat syngeneically transplanted (sTX) model served as the control (n = 6). Acute tubular necrosis (n = 6) and acute calcineurin inhibitor toxicity (n = 6) groups were established using Lewis rats. MRI was performed on postoperative day (POD) 1, 4 and 7 in the allogeneically transplanted (aTX) group and on POD4 in the other groups. Histological evaluation and PCR were performed.

RESULTS:

After the allogenic transplantation, all MRI parameters of allograft further decreased until POD7, and the D and ADC values in the cortex were significantly lower than that in the sTX group (1.03 ± 0.09 vs 1.52 ± 0.09 × 10-3 mm2/s, Padj < 0.05; 1.21 ± 0.03 vs 1.78 ± 0.07 × 10-3 mm2/s, Padj < 0.05). The D*, f and R2* values of the aTX group in the cortex and medulla were significantly lower than those in the sTX group on POD7 (cortex, D*: 25.60 ± 4.78 vs 69.32 ± 9.79 × 10-3 mm2/s, Padj < 0.05; f: 7.84 ± 1.83 vs 20.34 ± 3.08%, Padj < 0.05; R2*: 16.61 ± 4.18 vs 31.48 ± 6.43 1/s, Padj < 0.05; medulla, D*: 13.59 ± 6.08 vs 62.75 ± 9.20 × 10-3 mm2/s, Padj < 0.05; f: 7.46 ± 1.62 vs 14.68 ± 2.05%, Padj < 0.05; R2*: 21.59 ± 3.45 vs 39.53 ± 4.34 1/s, Padj < 0.05). AR grafts presented serve interstitial inflammation, tubulitis and infiltration of T-lymphocytes and macrophages. The MRI parameters, including D, ADC, D*, f and R2*, were significantly correlated with the histological changes, cell infiltration and inflammatory cytokine mRNA levels.

CONCLUSIONS:

IVIM coupled with BOLD MRI allows longitudinal assessment of allograft diffusion, perfusion and oxygen consumption impairment caused by acute renal allograft rejection in rat model.

• Authors: Song Zeng, Lu Liang, Qiang Zhang, Yue Xu, Hao Tang, Zijian Zhang, Xiaodong Zhang, Tao Jiang, Xiaopeng Hu
• Journal: Magnetic resonance imaging (Magn Reson Imaging) Vol. 58 Pg. 24-31 (05 2019) ISSN: 1873-5894 [Electronic] Netherlands
• PMID: 30630071 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 Elsevier Inc. All rights reserved.

Chemical References

• Calcineurin Inhibitors
• Oxygen

Topics

• Allografts
• Animals
• Calcineurin Inhibitors (chemistry)
• Diffusion Magnetic Resonance Imaging
• Disease Models, Animal
• Graft Rejection (diagnostic imaging)
• Kidney (diagnostic imaging, pathology)
• Kidney Transplantation
• Kidney Tubules (pathology)
• Magnetic Resonance Imaging
• Male
• Motion
• Necrosis (diagnostic imaging)
• Oxygen (blood)
• Polymerase Chain Reaction
• Rats
• Rats, Inbred Lew
• Transplantation, Homologous