强直性脊柱炎骶髂关节病变的影像学研究

分析了43例正常骶髂关节CT表现并对30例强直性脊柱炎(AS)骶髂关节病变作了双盲X线和CT对照研究,正常成人滑膜部关节间隙宽度为2～5mm,40岁后,关节前下部间隙可出现局部狭窄,骶侧皮质厚度多小于3mm,前后均匀者占90%;髂侧中部皮质厚度小于5mm,其前部皮质厚度可大于5mm(占16%),部分正常人可出现关节面不清晰,但无明确的侵蚀改变,关节面的侵蚀是诊断早期骶髂关节炎的重要条件,AS骶髂关节病变的对照研究表明:对平片可疑的病变,CT常可排除或肯定诊断,早期病变(Ⅱ级),CT可提高一个级别;Ⅲ、Ⅳ级病变CT和平片分级相同.CT扫描可用于临床高度怀疑而平片难以确诊者;对Ⅲ、Ⅳ级病变如仅为诊断,则CT扫描似并非必需.

Imaging Study of the Sacroiliac Joints in Ankylosing Spondylitis

Sacroiliac joint CT images of 43 normal individuls and X-ray and CT in evaluation of 30 patients with ankylosing spondylitis were blindly studied. The normal widths of the synovial part of sacroiliac joints were 2~5mm. After the age of 40 years anterior and inferior joint space may become narrow. The widths of sacral subchondral cortical plate were less than 3mm in 87% cases and uniform anterior-poslteriorly in 90%. The widths of middle part of iliac subchondral cortices were less than 5mm. The subchondral cortical plates of some normal controls may be indistinct but difinite erosions, never appeared. The author proposed that erosions are essential for the diagnosis of early sacroilitis. CT could exclude or prove sacroilitis for those of highly suspected or elevate one grade higher for grade II on plain film. The grades on CT and plain film were the same for grade I and grade IV sacroilitis. The writer considered that CT should be applied to those of highly suspected patients. Only to meet the diagnostic demands, it is unnecessary to take CT examination of sacroiliac joints for those with grade I and grade IV sacroilitis in ankylosing spondylitis.