个性化能谱协议在上腹部CT扫描中的应用

摘要

目的：通过优化选择能谱扫描协议，与常规120 kVp扫描图像质量及辐射剂量进行对比，探讨个性化能谱扫描在上腹部常规临床应用的可行性。资料与方法前瞻性收集行上腹部CT平扫加增强扫描的60例患者，将其随机分为A组和B组，每组30例。A组行常规120 kVp平扫加能谱增强扫描，B组行能谱平扫加120 kVp增强扫描。能谱扫描协议根据患者常规120 kVp、NI10-5 mm的平均毫安秒进行个性化选择，重建平扫和门静脉期120 kVp或70 keV序列图像。比较两组平扫和门静脉期CT容积剂量指数（CTDIvol）、有效剂量（ED），以及肝实质、脾实质、门静脉主干的标准差（SD）、信噪比（SNR）和对比噪声比（CNR）。结果 A组GSI门静脉期扫描的CTDIvol、ED小于120 kVp平扫（P>0.05）。B组GSI平扫的CTDIvol、ED小于120 kVp门静脉期扫描（P>0.05）。B组GSI平扫的CTDIvol、ED小于A组120 kVp平扫，A组GSI门静脉期扫描的CTDIvol、ED小于B组120 kVp门静脉期扫描，差异均无统计学意义（P>0.05）。B组GSI平扫在肝实质、脾实质和门静脉主干的SD均小于A组120 kVp扫描（P<0.05），SNR均大于A组120 kVp扫描（P<0.05）；A组GSI门静脉期扫描，在肝实质、脾实质和门静脉主干的SD均小于B组120 kVp门静脉期扫描（P<0.05）。结论优化后的个性化能谱扫描协议，辐射剂量略有减少，且能谱单能量图像质量的SNR、CNR优于或等于常规120 kVp扫描图像，并可提供多参数诊断及多应用平台，可在上腹部扫描中常规应用。%PurposeTo explore the feasibility of personalized energy spectrum scanning in upper abdomen CT by comparing the image quality and radiation dose of optimizing choice spectrum scanning protocol with conventional 120 kVp scan.Material and Methods Sixty patients undergoing abdominal CT scan with and without contrast enhancement were prospectively collected and randomly assigned into two groups. Group A (30 patients) underwent conventional 120 kVp scan and spectral enhancement scanning; group B (30 patients) underwent spectrum scan and 120 kVp enhancement scanning. Spectral scanning protocol was based on individual choice with conventional 120 kVp NI10-5 mm average mAs scan for every patient. The CT dose index of volume (CTDIvol) and effective dose (ED) during non-contrast phase and portal venous phase were recorded. The CT value, standard deviation (SD), signal noise ratio (SNR) and contrast noise ratio (CNR) were measured in the liver parenchyma, spleen parenchyma and portal venous trunk.Results The CTDIvol and ED of spectrum scanning were less than 120 kVp scan but there was no statistical difference (P>0.05). The SD of group B GSI imaging was less than group A 120 kVp (P<0.05), while the SNR was greater than group A. The SD of group A GSI portal venous phase in the liver, spleen and portal vein was less than group B 120 kVp (P<0.05).ConclusionThe optimized energy spectrum scanning protocol can reduce radiation dose with quality of single energy image from the energy spectrum equal to or better than the conventional 120 kVp scanning protocol. Personalized energy spectrum scan protocol provides multi-parameter diagnosis and multi-application platform and can be used routinely in the upper abdomen scan.