多层螺旋CT(MSCT)及多平面重建(MPR)鉴别穿孔与非穿孔性急性阑尾炎(NPAA)

Multi-slice CT(MSCT) with multiplanar reformation(MPR) in differentiating perforated from nonperforated acute appendicitis(NPAA)

目的研究穿孔性急性阑尾炎(perforated acute appendicitis,PAA)的多层螺旋CT(multi-slice CT,MSCT)表现,提高MSCT鉴别PAA与非穿孔性急性阑尾炎(nonperforated acute appendicitis,NPAA)的能力。方法经手术及病理证实的PAA 28例和NPAA 36例(其中急性单纯性阑尾炎18例,急性阑尾炎伴周围炎18例)行MSCT超薄层扫描,辅以多平面重建(multiplanar reformation,MPR)及曲面重建(curved multiplanarreformation,CPR)显示阑尾,观察、测量和比较PAA组与NPAA组诸CT征象的差异。结果 PAA组与NPAA组在阑尾壁强化缺损、阑尾周围脓肿、阑尾周围蜂窝织炎、阑尾腔外积气和阑尾腔外粪石5种CT征象的发生率差异均有统计学意义(P值分别为0.000、0.000、0.000、0.000、0.019),出现任一征象对PAA的诊断敏感度、特异度和准确度分别为96.4%、91.7%和93.8%。PAA组的阑尾直径为(16.2±3.8)mm,明显大于NPAA组[(11.3±3.1)mm,P=0.000)];当界值为13.3mm时,诊断PAA的特异度可提高至94.4%。结论 MSCT辅以MPR和CPR可准确鉴别PAA和NPAA,指导外科医师选择最佳治疗方案。

Objective To investigate the multi-slice CT（MSCT） findings of perforated acute appendicitis（PAA） to discriminate PAA from nonperforated acute appendicitis（NPAA）.Methods Twenty-eight patients with PAA proved by surgery and pathology underwent abdominopelvic MSCT ultrathin-section scan.Thirty-six patients with NPAA served as the control group（18 cases of simple AA and 18 cases of AA with associated periappendiceal inflammation）.The appendix was reconstructed by using multiplanar reformation（MPR） and curved multiplanar reformation（CPR） techniques.CT findings between PAA and NPAA were evaluated and compared.Results There were statistically significant differences between PAA and NPAA in defect in enhancing appendiceal wall,abscess,phlegmon,extraluminal air and extraluminal appendicolith（P=0.000,0.000,0.000,0.000 and 0.019,respectively）.Using any of the above five CT findings for diagnosis of PAA,the sensitivity,specificity and accuracy were 96.4%,91.7% and 93.8%,respectively. There was statistically significant difference in the appendiceal diameter between PAA [（16.2±3.8） mm] and NPAA [（11.3±3.1） mm].A cut-off value of 13.3 mm of appendiceal diameter for PAA improved the specificity to 94.4%.Conclusions MSCT combining MPR and CPR can accurately differentiate PAA from NPAA,which would help surgeon choose optimal management.