Semi-quantitative Analysis Of MRI And Spectral CT In Axial Spondyloarthritis With Sacroiliitis

Objective:To analyze the correlations between MRI sacroiliitis activity indexes and clinical AS activity indexes. Methods:Sixteen normal volunteers and fifty-two patients were enrolled. The MRI sacroiliitis activity indexes include surface difiusion coefficient (ADC) values of sacrum and ilium, and the Canada spinal arthritis research association (SPARCC) MRI index of sacroiliitis. The clinical AS activity indexes include Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score and laboratory tests erythrocyte sedimentation rate (ESR) and high sensitivity C-reactive protein (hsCRP). The Spearman correlation was used to analyze the correlation between the AS MRI inflammatory activity index and clinical inflammatory activity index, P<0.05for the difference was statistically significant. Results:The mean SPARCC score of the control group was0and of the AS group was9.9±9.1(range0-36). The mean ADC value of the AS group was statistically significantly higher than that of the control group ((49.7±20.2)×10-5mm2/s versus (38.9±5.3)×10-5mm2/s, p<0.05). The BASDAI score showed a statistically significant correlation with the SPARCC score (r=0.685, p<0.05) and with ADC-values (r=0.329, p<0.05). ADC-values correlated with the SPARCC score (r=0.390, p<0.05). The hsCRP value showed a statistically significant correlation with (r=0.767, P<0.05). Conclusion:SPARCC score and ADC value can be two useful indexes to detect the activity of AS, with the advantage of showing lesions intuitively. Objective:To study the value of dynamic contrast-enhanced MRI in evaluating the perfusion of subchondral bone and synovium in early axial spondyloarthritis with sacroiliitis. Objects and Methods:From October2013to November2014,47cases suspected with axial spondyloarthritis were collected. After3-6months follow-up,19patients were diagnosed as axial spondyloarthritis in accordance with the (Assessment of Spondyloarthritis international Society) ASAS criteria;28patients were diagnosed as unspecific low back pain (uLBP) patients (control group). All of the patients were performed the conventional and dynamic contrast enhanced MRI scan. The measurements included maximum level of enhancement (ME), rate of early enhancement (REE), rate of relative enhancement (RE), permeability contrast (Ktrans), volume of extravascular-extracellular space (Ve), efflux contrast (Kep) and initial area under curve (iAUC) of the subchondral bone and synovial in sacroiliac join. The independent sample T test was adopted to analyse the difference between SpA and control group. Results:In the19cases of SpA patients,6cases (6/19) showed focal bone hyperemia and edema in subchondral bone of sacroiliac joint,19cases (19/19) showed synovial hyperemia edema in sacroiliac joint. The ME and REE values of subchondral bone in SpA group were significantly higher than control group. The ME, REE, RE, Ktrans, Ve and iAUC values of the synovium in SpA group were significantly higher than control group. Conclusion:Through dynamic contrast enhanced MRI scanning measuring the enhancement rate and the pharmacokinetic parameters of subchondral bone and of synovium in sacroiliac joint can differentiate early axial spondyloarthritis from unspecific low back pain. The enhancement rates of synovhum in sacroiliac joints in SpA patients were significantly higher than unspecific low back pain patients. Purpose:To investigate the value of magnetization transfer contrast and diflusion weighted imaging in detecting the early sacroiliitis of patients with axial spondyloarthropathy (SpA). Material and Methods:84consecutive patients with low back pain and being suspected with axial SpA were recruited. All patients underwent MRI examinations. MTC was performed using three dimensional spoiled gradient recalled acquisition sequence (3D SPGR). The DWI was performed using echo-planar sequence with diffusion gradient b values of600s/mm2. Results:In84patients,16patients were diagnosed as unspecific low back pain (uLBP) patients (control group).68patients were diagnosed as axial SpA according the (Assessment of Spondyloarthritis international Society) ASAS criteria. The sensitivity of conventional MRI was63.2%in distinguishing axial SpA from uLBP patients. The mean MTR value of sacroiliac cartilage in axial SpA patient was smaller than control group (t=4.02, P<0.05). The mean sacral ADC value in axial SpA patient was larger than control group (t=-6.36, P<0.05). The mean iliac ADC value in axial SpA patient was larger than control group (t=-3.73, P<0.05). The sensitivity of MTR was75%in distinguishing axial SpA from LBP patients. The sensitivity of iliac and sacral ADC values were72.1%and63.2%in distinguishing axial SpA from LBP patients. Conclusion:MTC and ADC-values can evaluate the sacroiliitis of the SpA patients. In addition to the conventional MR sequences,3D SPGR combined with MT technique and diffusion weighted imaging might become sensitive tools for detecting the cartilage composition change of early SpA. Objective:To compare the clinical value of spectral CT and MRI in diagnosing axial spondyloarthritis (SpA) with sacroiliitis. Materials and Methods:137patients with low back pain (LBP) suspected axial-SpA were recruited. Each patient underwent sacroiliac spectral CT and MRI examinations. Water-and calcium-based material decomposition images were reconstructed for quantitative analysis. The CT value and bone marrow to normal muscle ratios of water concentration, calcium concentrations on spectral CT and signal intensity on STIR image in the ilium and sacrum were compared between unspecific low back pain (uLBP) and axial-SpA patients. Results: In137LBP patients,76were diagnosed with axial-SpA according to AS AS criteria whereas the remnant (49patients) were diagnosed with uLBP. There were statistically significant differences in ratio of water concentration, ratio of calcium concentration, CT values (HU), and ratio of signal intensity on STIR image between uLBP and axial-SpA patients (p<0.05) in the ilium. There were statistically significant correlations between ratio of water concentration and ratio of signal intensity on STIR images in both the ilium or sacrum (p<0.05). The sensitivity of iliac ratio of water concentration was higher than other parameters. The positive likelihood ratio of ratio of signal intensity was higher than other parameters. The diagnostic odd ratio of ratio of calcium concentration was higher than other parameters. Its negative likelihood ratio was also lower than other parameters. Conclusion:The spectral CT will provide more quantitative parameters for diagnosis of SpA with sacroiliitis. The spectral CT combined with MRI will improve the diagnostic efficiency of the axial SpA.