低管电压多层螺旋CT评估胆道支架恶性梗阻

发布时间：2018-09-19 19:18

【摘要】：目的本研究拟寻找能够诊断恶性胆道梗阻、并降低腹部螺旋CT扫描剂量的方法,探讨低管电压(100 k Vp)多层螺旋CT增强扫描显示金属胆道支架内恶性梗阻的图像质量及辐射剂量。资料与方法 2012年1月-2014年3月北京协和医院收治9例因自膨式金属胆道支架植入术后高度怀疑恶性梗阻复发患者,均行高分辨率CT三期动态增强扫描,对门静脉期CT增强扫描图像行曲面重组,然后测定184个层面的支架内CT值,分析140 k Vp和100 kVp两种管电压的重建图像质量,比较不同剂量对支架内软组织-肝脏对比噪声比(CNR)、平均图像噪声、图像质量因数(FOM)的差异。结果管电压由140 kVp降到100 k Vp时,图像噪声由(19.88±3.62)HU增加至(24.22±4.24)HU(P0.001),而CNR和FOM则分别改善15%和50%。结论采用100 k Vp低管电压能够显著增加恶性肿瘤组织-肝脏的CNR,并降低辐射剂量,低管电压CT技术对显示金属支架内恶性梗阻组织具有实用价值。
[Abstract]:Objective To find a method to diagnose malignant biliary obstruction and reduce the dose of abdominal spiral CT scan, and to evaluate the image quality and radiation dose of low-tube voltage (100 K Vp) multi-slice spiral CT enhanced scan for malignant biliary obstruction in metallic biliary stents. All patients with highly suspected recurrence of malignant obstruction after expandable metallic biliary stent implantation underwent three-phase dynamic contrast-enhanced CT scan with high resolution. The CT images of portal vein phase were reconstructed with curved surface. The CT values of 184 layers were measured. The reconstructed image quality of 140 kVp and 100 kVp tube voltages was analyzed and compared. Results When the tube voltage decreased from 140 kVp to 100 kVp, the image noise increased from (19.88.62) HU to (24.22.24) HU (P 0.001), while CNR and FOM improved by 15% and 50% respectively. Tissue-liver CNR and low-tube voltage CT have practical value in displaying malignant obstructive tissue in metal stents.
【作者单位】：中国医学科学院协和医学院北京协和医院放射科;海口市人民医院放射科;
【基金】：海南省自然科学基金项目(813261) 海口市重点计划项目(2012-075)
【分类号】：R657.4;R816.5

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