The Study Of Measurement Of Renal Perfusion By Dynamic CT And Its Clinical Application

Objective: Perfusion CT has been proved to be effective to early diagnose the ischemic disease of brain, and has also been used to measure perfusion in the liver and kidney. The purpose of the present study was to investigate the potential of dynamic CT in measurement of the perfusion of kidney, and the clinical value of CT perfusion in diagnosis of renal tumors was assessed.Materials and methods: Nomal group: 52 volunteers were studied in this group. A single level through the renal hili and aorta was scanned after intravenous injection of 40～50ml of contrast agent given at 5.0ml/s on a breath hold with testbolus sequences. Time-density curves were then drawn for both renal cortal and aorta using regions of interest (ROI), and renal cortal perfusion was calculated as the peak upslope of the tissue time-density curve divided by peak aortic enhancement. The following statistic analysis were performed: renal cortal perfusions were compared to determine whether there were significant difference between right and left, male and female. And the correlation between age and perfusion was analyzed too. Group of tumors: 30 cases of renal tumors were studied in this group, including 20 cases of renal cell carcinoma (RCC), 4 cases of renal pelvic carcinoma (RPC), 6 cases of renal agiomyolipoma (RAML). 20 cases of RCC were divided into two groups based on clinical stages: local group(12 cases) and transfered group (8 cases), and they were divided into two other groups based on pathological stages: low active group (11 cases) and middle or high active group (9 cases). Perfusion of renal tumors were measured in the same way as nomal group. And the perfusions were compared to determine whether there were significant difference between local group and transfered group, low active group and middle or high active group. Results: Perfusion of normal renal cortex is 2.68±0.40ml/min/ml, there is no difference between right and left renal cortal perfusions, but there is significant difference between male and female renal cortal perfusions. And renal cortal perfusion has contrary correlation with age. Perfusion of RCC is 1.51±0.68ml/min/ml. Perfusion of transfered group of RCC is significantly higher than that of local group, and perfusion of middle or high active group of RCC is also significantly higher than that of low active group. Renal cortal perfusion is much higher than perfusion of RCC, and perfusion of RCC is much higher than that of other two renal tumors.Conclusion: Measurement of renal perfusion with dynamic CT is feasible, and has potential clinical application value.