Jan Ya-Ting, Yang Fei-Shin, Huang Jon-Kway
Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan 10449, Province of China.
J Comput Assist Tomogr. 2005 Jul-Aug;29(4):446-51. doi: 10.1097/01.rct.0000164668.03767.53.
To evaluate the visualization rate and describe the morphologic pattern of the normal appendix on multidetector CT (MDCT) by using multiplanar reformation display.
We conducted a retrospective evaluation of the normal appendix with MDCT in 108 consecutive patients. A radiologist blinded to patient surgery history reviewed multiplanar reformation images at the workstation. The coronal and sagittal reformation images were reviewed in addition to the axial images. The visualization rate and morphologic pattern (including location, diameter, and lumen content) of normal appendices were recorded.
The prevalence of appendectomy was 9% (10 of 108 patients). The appendix was recorded as definitely visualized in 91 of 98 patients who denied a history of appendectomy, definitely not visualized in 13 patients, and unsure in 4 patients. For statistical analysis, the definitely not visualized and unsure cases were summed and categorized as not visualized. The sensitivity, specificity, positive and negative predictive values, and accuracy of visualization of the normal appendix by MDCT were 93%, 100%, 100%, 59%, and 94%, respectively. All the patients in the unsure group had ascites or inadequate pericecal fat, or both. The mean outer diameter of the appendix was 5.6 +/- 1.3 mm (SD) (range: 3.0-11.0 mm).
We verify a high visualization rate (93%) of normal appendices on MDCT by using multiplanar reformation display.
通过多平面重组显示评估多层螺旋CT（MDCT）对正常阑尾的显示率并描述其形态学特征。
我们对108例连续患者的正常阑尾进行了MDCT回顾性评估。一位对患者手术史不知情的放射科医生在工作站查看多平面重组图像。除了轴位图像外，还查看了冠状位和矢状位重组图像。记录正常阑尾的显示率和形态学特征（包括位置、直径和管腔内内容物）。
阑尾切除术的发生率为9%（108例患者中的10例）。在98例否认有阑尾切除术病史的患者中，91例阑尾被明确显示，13例明确未显示，4例情况不确定。为进行统计分析，将明确未显示和情况不确定的病例汇总并归类为未显示。MDCT对正常阑尾的显示的敏感性、特异性、阳性和阴性预测值以及准确性分别为93%、100%、100%、59%和94%。情况不确定组的所有患者均有腹水或盲肠周围脂肪不足，或两者皆有。阑尾的平均外径为5.6±1.3毫米（标准差）（范围：3.0 - 11.0毫米）。
我们通过多平面重组显示验证了MDCT对正常阑尾的高显示率（93%）。
