Ruxin Wang, Presenter: Nothing to Disclose

Yue Dong, Abstract Co-Author: Nothing to Disclose

Liwei Zhong, Abstract Co-Author: Nothing to Disclose

liang huang, Abstract Co-Author: Nothing to Disclose

 To evaluate the efficacy of DCE-MRI in the differential diagnosis of active lesions in the sacroiliac joint of ankylosing spondylitis(AS) patients.

Two groups of patients were selected: confirmed cases and clinical suspected (35 cases), normal control group (21 cases). The age limit is 18 to 45 years old and male to female ratio is about 1 to 1. Two sequences are performed: fat suppressed T2WI and joint DCE - MRI T1WI of both sacroiliac joints in the sagittal and coronal plane. The slice thickness is 4 ~ 5 mm. The contrast is given every 10 ms, at an interval of 1 ms, when scan 20 phases .The patient is scanned in the coronal and sagittal section. The bilateral sacroiliac joints are examined for any synovial thickening and the synovium is measured. At each level, 3 ROI are taken from right to left. ,as far as possible when selecting ROI and synovial contorts the consistent, according to the TIC curve we can respectively record time to the peak(TTP), peak signal strength(PSS), the maximum slope (MSI) and signal enhancement ratio (SER), Independent sample t test analysis is used to compare the average value.

Based on clinical, laboratory examination and image analysis, 17 cases had confirmed symptomatic AS and 18 cases had no confirmed AS. For the control group: the peak time is (9.48+ / - 4.11) ms; the peak signal strength is (430.51+ / - 146.55); the largest rise in slope is (78.78 + / - 42.84); the signal enhancement ratio is (85.89+ / -36.10).For the lesion group: the peak time is (13.00 + / - 5.06) ms ;the peak signal strength is (571.81 + / - 241.24) ;The largest rise in slope is (141.93+ / -78.42); the signal enhancement ratio is (124.74 + / - 97.63). The comparison between lesion group and control group had statistical significance (P < 0.05). The peak time area under the ROC curve(AUC) is 0.71. the peak signal strength AUC is 0.74; the maximal peak AUC is 0.78;the signal enhancement ratio AUC is 0.72.

DCE-MRI is superior to conventional sequences of MRI in the differential diagnosis of active lesions in the sacroiliac joint of ankylosing spondylitis. Parameters such as time to peak, peak signal strength, maximum rising slope, signal enhancement ratio of sacroiliac joint of active lesions has significance of differential diagnosis. The efficiency is the largest at the maximal increase in slope.

It's a new method that is very helpful to diagnosis of AS.

Wang, R, Dong, Y, Zhong, L, huang, l, Feasibility of DCE-MRI in the Detection of Active Lesions of Ankylosing Apondylitis in the Sacroiliac Joint.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017626.html