宝石探测器CT与常规探测器CT对正常胰管显示的比较

目的 探索宝石探测器CT与常规探测器CT显示正常胰管能力的差异。方法 对30例恶性肿瘤患者行宝石探测器CT腹部增强扫描,患者既往均曾接受常规探测器CT扫描。宝石探测器CT应用HD模式薄层扫描及重建,FOV采用36 cm及18 cm两种模式。常规探测器CT采用常规模式扫描并薄层重建,FOV 36 cm。比较两种扫描图像对胰管的显示范围、清晰程度,计算并比较胰管的SNR及胰管与邻近胰腺的CNR、信号强度比(SIR)。记录并比较两次扫描的扫描剂量。结果 常规探测器CT及宝石探测器CT两种模式图像对胰管的显示范围(P=0.178)及清晰程度(P=0.529)差异无统计学意义,胰管与胰腺组织的SIR差异也无统计学意义(P=0.337)。宝石探测器CT两种重建图像SNR及CNR均低于常规探测器CT图像(P=0.002、0.005)。应用宝石探测器CT HD扫描模式的扫描剂量明显低于常规探测器CT扫描(P<0.001)。结论 宝石探测器CT可以在保证胰管的显示率及清晰程度前提下明显减低扫描剂量。

Evaluation of normal pancreatic duct: Comparison between garmstone detectors CT and conventional multi-detector CT

Objective To compare the ability of garnet-based detectors CT and conventional multi-detector CT in visualizing normal pancreatic duct. Methods Thirty patients with malignant tumors who underwent conventional multi-detector CT firstly were examined with gemstone detectors CT. The HD mode and thin slice reconstruction were applied in garnet-based detectors CT, and two kinds of FOV (36 cm and 18 cm) were used. In conventional multi-detector CT, normal mode and thin slice reconstruction were selected, and FOV of 36 cm was set. The visualization range and definition of pancreatic ducts were compared. The pancreatic duct-to-parenchyma contrast-to-noise ratio (CNR), signal intensity ratio (SIR), pancreatic duct's signal to noise ratio (SNR), noise and effective dose were analyzed. Results No statistical difference in visualization and sharpness of pancreatic duct was observed between the two protocols (P=0.178, 0.529), nor in SIR (P=0.337). Compared with gemstone detectors CT, conventional multi-detector CT yielded significantly greater pancreatic duct-to-parenchyma CNR (P=0.005) and SNR (P=0.002). The effective dose of gemstone detectors CT significantly reduced than conventional multi-detector CT (P<0.001). Conclusion HD scan mode of gemstone detectors CT has the potential to reduce patient radiation dose without decreasing the conspicuity of the pancreatic duct during the pancreatic parenchymal phase of CT scan.