Application Of DCE-MRI And DWI In Sacroiliac Arthritis In Ankylosing Spondylitis

Objective:Step one:To study the value of dynamic contrast enhanced magnetic resonance imaging(DCE-MRI)and diffusion-weighted imaging weighted imaging(DWI)in the early diagnosis of sacroiliac arthritis in ankylosing spondylitis.Step two:To study the value of DCE-MRI combined with DWI in evaluating the activity of sacroiliac arthritis in ankylosing spondylitis.Methods: Experiment one:Collecting 34 cases of ankylosing spondylitis diagnosed as early ankylosing spondylitis from March 2016 to November 2017,affiliated to the Yaji Mountain Hospital of Southern Anhui Medical College(Standard of early diagnostic:Course of disease less than 1 year,The clinical manifestation and laboratory examination all accord with the diagnostic standard of ankylosing spondylitis,and X-ray and CT examination showed no abnormal imaging findings of sacroiliac joint,that is,early ankylosing spondylitis.).Average age 25.13 ±7.32 years;To collect 15 cases of normal control group were collected;The average age was 24.71 ±4.62 years old.To measured ADC and DCE-MRI parameters of sacroiliac joint bone,and to compared the differences of ADC and DCE-MRI semi-quantitative parameters between the early group and the normal control group.To analyzed the correlation between the ADC value and the Senh value of the early group.Experiment two:collecting 53 cases of ankylosing spondylitis(including 34 cases in the early group of experiment one and 19 cases in the reexamination of AS).The average age 26.13 ±8.74 years;According to the assessment of sacroiliac arthritis activity in patients with as(discussion on the basis of activity Evaluation Group of the paper later).Redivided into active group(38 cases)and stable group(15 cases)in 53 patients with AS.To compared the difference of ADC value and DCE-MRI semi-quantitative parameter value between active group and stable group.Use the SPSS16.0 software to draw the ROC curve,calculate the AUC,and calculate the sensitivity,specificity and Youden index of the diagnosis of as sacroiliac arthritis by DWIX DCE-MRI and their combination.Results one: 1.34 patients with ankylosing spondylitis ADC mean value of abnormal signal intensity in sacroiliac articular surface was1.08 ± 0.19(× 10-3mm 2 / s)significantly higher than the normal control group ADC mean 0.35 ± 0.04(×10-3mm 2 / s),The difference between the two groups was statistically significant(P <0.05).2.Determination of abnormal enhanced area of sacroiliac joint in 34 patients with ankylosing spondylitis in early group,The value of Fenhan in the area of interest is246.08 ±82.31,the value of Senhmin is 80.63 ±41.43,and the peak time is 2.79 ±0.96.The semi-quantitative values of Fenh(%)28.08 ± 9.38 and Tmax(min)4.31 ±0.26 in 15 normal controls were 32.22 ±11.78 and 0.26,respectively.T test showed that there were significant differences in parameters between the two groups(P <0.05).3.There was a linear relationship between the ADC value in the active lesion area and the Fenh value of the enhancement factor in the early group(P < 0.05),the correlation coefficient is 0.89 with highly correlated.There was also a linear correlation between the ADC value of the active lesion area and the Senh value of the enhancement slope in the early group(P < 0.05),and the correlation coefficient was0.56.Results two: 1.38 active group mean of abnormal high-intensity ADC in the sacroiliac articular surface in was 0.85 ±0.22.The average value of ADC in 15 cases of stable group was 0.48 + 0.20(x 10-3mm2/s).The difference between the active group and thestable group was statistically significant(P < 0.05).2.In 38 cases of active group,the value of Senh(min)was 94.08 ±42.61 and SImax was 752.46 ±104.84,the value of Fenh(%)was 230.70 ± 92.60.In 15 cases of stable group,the value of abnormal enhancement area of sacroiliac articular surface Fenh(%)was 132.10 ± 37.21,the value of Senh(%min)is 131.30 ± 62.90 and SImax is 493.10 ± 171.73.The difference of parameters between active group and stable group was statistically significant(P < 0.05).3.In evaluating activity,the area under the four parameter curves of the activity group SImax / Fenhan / Senhan ADC value is: 0.915 / 0.853 / 0.607 / 0.891,The maximum area under the SImax curve was 0.915,followed by the area under the ADC curve.The diagnostic threshold of SImax is 630.85,the sensitivity is 93%and the specificity is 86.7%.The diagnostic limit of ADC value is 0.602(× 10-3mm 2 /s),the sensitivity was 95% and the specificity was 80%.When DCE-MRI and ADC jointly judge activity,the area under the curve is 0.930,the area under the curve is0.930,the sensitivity is 95 %and the specificity is 86.7%.Conclusion one:DWI and DCE-MRI imaging are valuable in the diagnosis of sacroiliac arthritis in ankylosing spondylitis,the area of the lesion is very sensitive.The ADC value of lesion area in early active patients was significantly higher than that in normal control group.The value of Fenh and Senh was higher than that of normal control group,Tmax value is lower than that of control group.The ADC value was correlated with the Fenh /Senh value,and had a high correlation with the former.Conclusion two:DCE-MRI and DWI showed high sensitivity and specificity in evaluating the activity of sacroiliac arthritis in ankylosing spondylitis,have high diagnostic value.The diagnostic efficacy of the two methods was better than that of a single index.