Application value of curved planar reconstruction in sacroiliac joint of ankylosing spondylitis

Objective To determine the application value of curved planar reconstruction(CPR)of multislice spiral computed tomography(MSCT)in changes of sacroiliac joint of ankylosing spondylitis(AS).Methods 33 patients with AS diagnosed clinically were chosen to take MSCT scanning of bilateral sacroiliac joints with the slice thick of 5mm and the slice interval of 5mm.The primary images were transported to General Electric AW4.0 workstation,and the multiplanar reformatted sagittal images of sacrum were obtained by the reformat software,and further the coronary images of bilateral sacroiliac joints by CPR with the construction curves coincident with sacrums.Results All coronary images of bilateral sacroiliac joints by CPR were excellent in density and space resolution,and showed complete sacroiliac joints and their changes clearly and directly.Of all 33 cases,2 were graded as grade 0,5 gradeⅠ,11 gradeⅡ,10 gradeⅢ,5 gradeⅣ,according to grading standard.Conclusion The coronary images of sacroiliac joint by CPR are enough clear and eligible for clinical diagnosis,and,in combination with transversal images,are helpful to complete assessment about the grade and scope of changes of sacroiliac joint in AS patients.