骶髂关节CT检查骶管囊肿的检出率及漏诊分析

目的 探讨骶髂关节CT扫描检查骶管囊肿的检出率及漏诊原因.方法 回顾性分析1286例骶髂关节CT扫描患者的骶管改变情况.CT扫描包括骨算法重建及标准算法重建.结果 骶髂关节CT扫描阴性的1 025例患者中发现骶管囊肿36例,检出率为3.5％（36/1 025）.其中单发囊肿34例,多发囊肿2例.囊肿位于S1水平5例,S1～2水平4例,S2水平22例,S2～3水平4例,S3水平3例.囊肿最小短径0.5 cm,最大长径3.2 cm,平均1.2 cm.CT表现为类圆形密度均匀的囊性低密度影,伴有骶管扩大19例.CT扫描采用骨算法重建29例,采用标准算法和骨算法重建7例.临床发现并正确诊断11例,仅占30.6％（11/36）,约69.4％（25/36）病例出现漏诊.结论 骶髂关节CT扫描阴性患者骶管囊肿检出率约为3.5％,CT扫描宜同时采用标准算法和骨算法重建,以避免漏诊.

The analysis of the sacroiliac joint CT examination in the detection rate and missed diagnosis of sacral canal cyst

Objective To investigate the detection rate and missed diagnosis reason of sacral canal cyst with sacroiliac joint CT scan. Methods Retrospectively analyzed the changes of sacral canal in 1 286 cases with sacroiliac joint CT scan. CT scanning included bone algorithm reconstruction and standard algorithm reconstruction. Results Among 1 025 patients who had negative sacroiliac joint CT scan were found in 36 cases of sacral canal cyst, the detection rate was 3.5% （36/1 025）. Single cyst in 34 cases and multiple cysts in 2 cases. Cyst in S1 level 5 cases, S1-2 level 4 cases, S2 level 22 cases, S2-3 level 4 cases, S3 level 3 cases. The minimal short diameter of the cysts was 0.5 cm and the maximal diameter was 3.2 cm, average 1.2 cm. CT scan showed a round uniform cystic low density,and combined with sacral canal expansion in 19 cases. CT scan used bone algorithm reconstruction in 29 cases,used standard and bone algorithm reconstruction in 7 cases. Clinical findings and correctly diagnosed in 11 cases, accounted for 30.6% （11/36）, about 69.4%（25/36） cases were missed diagnosis. Conclusions About 3.5% patients are found sacral canal cyst who have negative sacroiliac joint CT scan. Both the standard and bone algorithm reconstruction should be used to avoid the missed diagnosis of sacral canal cyst.