多层螺旋CT诊断早期急性阑尾炎的价值

Multi-slice CT diagnosis of early acute appendicitis

目的探讨MSCT对早期急性阑尾炎（AA）的诊断价值。方法回顾性分析2008年6月至2011年6月期间，经手术病理证实的41例急性单纯性阑尾炎的MSCT扫描资料；并将同期因病情需要行MSCT检查，且经临床证实为正常阑尾的36例患者作为对照组，其中复杂病变正常阑尾（CNA）组18例，非复杂病变正常阑尾（NCNA）组18例。采用MPR和CPR法进行后处理显示阑尾，观察测量早期AA与正常阑尾在阑尾直径、壁厚度、腔内液体最大直径（MDIAF）、壁异常强化、粪石和周围情况的差异，并采用方差分析、秩和检验和卡方检验进行比较。结果早期AA组、CNA组和NCNA组患者的阑尾壁厚度分别为（2．88±0．62）、（2．58±0．50）和（2．73±0．53）mm，差异无统计学意义（r=1．73，P=0．19）；直径分别为（11．37±1．94）、（7．03±0．89）和（6．75±0．63）mm，MDIAF中位数分别为4．05（2．65～8．50）、1．68（0—4．40）和0．00（0～1．90）mm，差异均有统计学意义（Z值分别为7．02和7．24，P值均为0．0C）。上述3组CT增强扫描阑尾壁异常强化的发生率分别为61．1％（11／18）、16．7％（3／18）和11．1％（2／18），早期AA组与正常阑尾组差异有统计学意义（X2=12．83，P=0．00）。当阑尾直径和MDIAF的界值分别为7．8和2．6mm时，诊断早期AA的敏感度、特异度和准确度分别为97．6％（40／41）、91．7％（33／36）、94．8％（73／77）和100．0％（36／36）、88．9％（32／36）、94．4％（68／72）。结论MSCT在诊断早期AA具有价值，当阑尾直径〉7．8mm、MDIAF〉2．6mm时，可早期诊断AA。

Objective To investigate the value of multi-slice CT （MSCT） in diagnosing early acute appendicitis （AA）. Methods From June 2008 to June 2011, abdomen MSCT images of 41 patients with acute simple appendicitis confirmed by surgery and pathology were evaluated retrospectively. Thirty-six patients with clinically confirmed normal appendix served as the control groups with 18 patients in complicated-normal-appendix （CNA） group and 18 patients in noncomplicated-normal-appendix （NCNA） group. The appendix was reconstructed by using muhiplanar reformation （MPR） and curved planar reformation （CPR） techniques. The differences between early AA and normal appendix in appendiceal diameter, thickness of the appendiceal wall, maximum depth of the intraluminal appendiceal fluid （MDIAF）, abnormal enhancement of the appendiceal wall, appendicolith and the periappendiceal abnormalities were evaluated and compared by using analysis of variance, R test and Chi-square test. Results The mean thickness of the appendieeal wall was （2. 88 ±0. 62） , （2. 58±0. 50） and （2. 73 ±0. 53） mm in early AA, CNA and NCNA groups respectively, with no statistically significant difference among them （ F = 1.73, P=0.19）. The mean appendiceal diameter was （11.37 ± 1.94）, （7.03 ±0.89）, （6.75 ± 0. 63 ） mm, and median MDIAF was 4. 05 （ 2. 65--8.50）, 1.68 （0-4.40） , 0 （0-1.90） mm in early AA, CNA and NCNA groups respectively, with statistically significant differences between early AA and the two normal appendix groups （ Z = 7.02,7.24 ; P = 0. 00 ）. The abnormal enhancement of appendiceal wall was found in 61.1% （11/18） of early AA, 16. 7% （3/18） of CNA and 11.1% （2/18） of NCNA groups respectively, with statistically significant differences between early AA and the two normal appendix groups （ x2 = 12. 83, P = 0. 00）. Using a cutoff value of 7.8 mm of the appendiceal diameter and 2. 6 mm of MDIAF for the early AA, the sensitivity, specificity and accuracy were 97.6% （40/41）, 91.7% （33/36） and 94. 8% （73/77） , and 100. 0% （ 36/36）, 88. 9% （32/36） and 94. 4% （68/72）, respectively. Conclusions MSCT is particularly useful for the diagnosis of early AA. When appendiceal diameter is greater than 7.8 mm, and MDIAF greater than 2. 6mm, early AA can be diagnosed with confidence.