急诊疑似阑尾炎VCT平扫与术后病理诊断对照准确性研究及影像学特征

目的以手术和病理诊断为金标准,探讨VCT平扫对急诊疑似阑尾炎的诊断价值。方法 2008年6月至2009年5月对急诊疑诊阑尾炎患儿行VCT平扫检查,与随后进行的外科手术病理学检查结果对照。统计分析VCT平扫诊断的准确性、敏感度、特异度、阴性似然比及阳性似然比。并分析急性阑尾炎和其他急腹症的VCT影像学特征。结果 284例患儿中手术和病理学检查诊断急性阑尾炎270例,VCT平扫诊断急诊阑尾炎243例。VCT平扫对急诊阑尾炎的诊断准确性为90%(95%CI:87%～92%)、敏感度为0.91(95%CI:0.87～0.94)、特异度为0.89(95%CI:0.85～0.93)。进一步根据阑尾炎病理学检查结果行亚组分析,结果显示,急诊单纯性阑尾炎的VCT诊断准确性为62.3%,急诊化脓性、坏疽性和穿孔性阑尾炎的诊断准确性均95%。漏诊和误诊的27例急诊阑尾炎中,包括23例单纯性阑尾炎,4例化脓性阑尾炎(3例被误诊为盆腔右侧附件病变,1例被误诊为右侧输尿管下端结石)。284例中14例为其他原因急腹症,VCT平扫准确诊断11例(78.7%),漏诊3例,包括肠系膜裂孔疝、梅克尔憩室扭转及索带压迫各1例。急性阑尾炎患儿典型的VCT特征为阑尾周围脂肪间隙模糊,阑尾增粗(直径为5～19mm),阑尾壁增厚。结论 VCT平扫对于急诊疑似阑尾炎的诊断具有显著意义,但对于单纯性阑尾炎的诊断准确性较低,必要时应行增强VCT检查以提高诊断准确性。

Study on accuracy of VCT in disgnosis of pediatric acute abdomen with suspected appendicitis compared with surgical pathology and imaging features

Objective To study the value of non-enhanced voluminal computed tomography (NEVCT) in diagnosis of pediatric acute abdomen with suspected appendicitis. Methods Children suspected of appendicitis were referred for abdominopelvic NEVCT examination from June 2008 to May 2009. All patients were sequentially undergone surgical operation. The VCT findings were analyzed and compared with the results of surgical pathology. Accuracy, sensitivity, specificity, and positive likehood ratio were calculated. The features of the VCT of the acute appendicitis and other acute abdomen were summarized. Results Two hundred and seventy of 284 patients with appendicitis were confirmed by surgery and pathology. In these patients, 243 cases were diagnosed by pre-operation NEVCT. The accuracy of VCT for detecting appendicitis was 90.0％（95%CI：87%-92%）, the sensitivity was 0.91（95%CI：0.87-0.94）and the specitivity was 0.89（95%CI：0.85-0.93）. According to the surgical pathology, the results showed the diagnostic accuracy of early appendicitis by VCT was 62.3%, the accuracy of the others (suppurative appendicitis, gangrenous appendicitis, perforating appendicitis) were all above 95%. The other 27 cases were misdiagnosed by VCT including early appendicitis (23 cases) and suppurative appendicitis (4 cases). In the latter, 3 cases were diagnosed by VCT as the right ovarian conditions and the other one as the right urinary calculus. In 284 patients, 14 children were not appendicitis confirmed by surgery, and 11 cases were accurately diagnosed by pre-operation NEVCT. However, the other 3 cases with mesenteric hiatual hernia, Meckel′s diverticulum were misdiagnosed by pre-operation NEVCT. VCT scan showed vague fat space around appendix, thick appendix 5-19 mm in diameter and thickened wall. Con clusionsPre-operation NEVCT scan is an essential method in pediatric acute abdomen with suspected appendicitis. It shows lower accuracy of VCT in diagnosis of early appendicitis; however, for the patients without typical CT findings of appendicitis, enhanced VCT can be used if necessary.