Chengyan Wang1, Bihui Zhang2, Haochen Wang3, Hanjing Kong4, Fei Gao5, Xiaoying Wang6, Min Yang7, Jue Zhang8. 1. Human Phenome Institute, Fudan University, Shanghai, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China. 2. Department of Interventional Radiology and Vascular Surgery, Peking University First Hospital, Beijing, China. 3. Department of Interventional Radiology, Beijing Friendship Hospital, Beijing, China. 4. Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China. 5. College of Engineering, Peking University, Beijing, China. 6. Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; Department of Radiology, Peking University First Hospital, Beijing, China. 7. Department of Interventional Radiology and Vascular Surgery, Peking University First Hospital, Beijing, China. Electronic address: dryangmin@gmail.com. 8. Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; College of Engineering, Peking University, Beijing, China. Electronic address: zhangjue@pku.edu.cn.
Abstract
PURPOSE: To investigate the feasibility of using MRI based oxygenation imaging for early assessment of ischemic acute kidney injury (AKI) in an embolization model. METHODS: Ischemic AKI model was induced in 40 rabbits by injection of microspheres into the right renal arteries. Animals were grouped according to the dose of microspheres: Severe AKI group, 2.0 mg (N = 10); Moderate AKI group, 1.0 mg (N = 10); Mild AKI group, 0.5 mg (N = 10); Control group, saline without microspheres (N = 10). A serial MRI examination was performed at intervals of 1 h, 1 day, 1 week and 4 weeks to evaluate the deterioration of renal function. A multi-echo ASE sequence was implemented for renal oxygenation measurement 1 h after surgery. Pathological examinations were performed 4 weeks after the surgery. RESULTS: In renal cortex, renal oxygen extraction fraction (OEF) raised significantly after embolization procedures in all experimental groups (severe AKI: 0.39 ± 0.05, P < 0.05; moderate AKI: 0.36 ± 0.03, P < 0.05; mild AKI: 0.34 ± 0.02, P < 0.05) compared to the control group (0.29 ± 0.02). In outer medulla, significant difference was observed between control group (0.29 ± 0.03) and severe AKI group (0.35 ± 0.03, P < 0.05), and between control group and moderate AKI group (0.34 ± 0.04, P < 0.05). Corresponding lesions were found in pathological examinations 4 weeks after the procedure. CONCLUSION: This study demonstrates the feasibility of using oxygenation imaging to assess the embolization induced ischemic AKI at an early stage.
PURPOSE: To investigate the feasibility of using MRI based oxygenation imaging for early assessment of ischemic acute kidney injury (AKI) in an embolization model. METHODS:Ischemic AKI model was induced in 40 rabbits by injection of microspheres into the right renal arteries. Animals were grouped according to the dose of microspheres: Severe AKI group, 2.0 mg (N = 10); Moderate AKI group, 1.0 mg (N = 10); Mild AKI group, 0.5 mg (N = 10); Control group, saline without microspheres (N = 10). A serial MRI examination was performed at intervals of 1 h, 1 day, 1 week and 4 weeks to evaluate the deterioration of renal function. A multi-echo ASE sequence was implemented for renal oxygenation measurement 1 h after surgery. Pathological examinations were performed 4 weeks after the surgery. RESULTS: In renal cortex, renal oxygen extraction fraction (OEF) raised significantly after embolization procedures in all experimental groups (severe AKI: 0.39 ± 0.05, P < 0.05; moderate AKI: 0.36 ± 0.03, P < 0.05; mild AKI: 0.34 ± 0.02, P < 0.05) compared to the control group (0.29 ± 0.02). In outer medulla, significant difference was observed between control group (0.29 ± 0.03) and severe AKI group (0.35 ± 0.03, P < 0.05), and between control group and moderate AKI group (0.34 ± 0.04, P < 0.05). Corresponding lesions were found in pathological examinations 4 weeks after the procedure. CONCLUSION: This study demonstrates the feasibility of using oxygenation imaging to assess the embolization induced ischemic AKI at an early stage.