MSCT增强扫描MPR和VR重建对下咽癌评估的价值

摘要

目的 探讨螺旋CT增强扫描及二维多平面重建(Multi-Planar Reconstruction,MPR)、三维VRT (Volume Rendering Technique)后处理技术对下咽癌病情术前评估的价值.方法 回顾性分析25例经病理证实的下咽癌患者,所有病例术前均行64排螺旋CT平扫、三期增强扫描及MPR、VRT后处理,并与喉镜及手术所见进行对照分析,比较CT横轴位图像、MRP及VRT图像在下咽癌诊断及周围结构侵犯、颈淋巴结转移评估的价值.结果 25例患者中,包括梨状隐窝癌18例,环后区癌4例,下咽后壁癌3例.螺旋CT平扫、增强扫描及其MPR、VRT图像对下咽癌的诊断和颈部淋巴结转移诊断的准确度分别是94.4％和98％.其中,增强图像有助干肿瘤病灶的显示及其侵犯范围的判断,增强扫描静脉期冠状位MPR图像对于颈部淋巴结转移的显示明显优于横轴位图像.结论 螺旋CT横轴位图像结合MPR、VRT后处理技术,能清楚显示下咽癌病灶及其侵袭范围、颈部淋巴结转移情况,并能直观显示气道狭窄程度,有利于更好地制定手术计划.%Objective To evaluate the clinical implications of MRP and VRT post-prcessing technique on the images of MSCT in the diagnosis and staging of hypopharyneal cancers as carried out preoperatively based on a clinical trial.Methods A retrospective study was carried out among 25 patients with hypopharyngeal cancer diagnosed histopathologically.All these cases received 64-slice spiral CT regular scanning,phase Ⅲ enhanced scanning and multiplannar reconstruction (MPR) and volume rendering technique (VRT) post-precessing on the images.Then,a comparative analysis was made to evaluate the correlation of images with the findings obtained from laryngoscopy and during the operation in order to compare the value of axial CT,MPR and VRT images in the diagnosis of hypopharyngeal cancers and in the evaluation of its invasive extent and neck node metastasis.Results Of the 25 cases,18 were diagnosed as piriform fossa cancer,4 were post-cricoid region cancer,and 3 were posterior hypopharyngeal wall cancer.The diagnostic accuracy of helical CT plain scan,axial view CT enhancement scanning,and MPR and VRT images post-processing technique were 94.4％ and 98％ respectively in the pre-operative diagnosis of focus and neck lymph node metastasis.It was suggested that enhanced images could more clearly show the tumor focus and the invasive extent of the lesion.Especially,venous-phase coronal plane MPR images could demonstrate neck lymph node metastsis much more clearly than that of axial view images.Conclusion Helical CT axial view images combining with MPR and VRT postprocessing technique can clearty demonstrate the focus of hypopharyngeal carcinoma,invasive extension of tumor and metastatic neck lymph nodes.Furthermore,the serverity of narrow in air passage can be directly shown as well.This will be very helpful for making the operating plan preoperatively.