The analysis of the sacroiliac joint CT examination in the detection rate and missed diagnosis of sacral canal cyst / 中国医师进修杂志

ABSTRACT

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.