Exploration into quantitative MR diagnostic criteria of subacromial impingement syndrome / 实用放射学杂志

ABSTRACT

Objective To investigate the relationships of MR indexes such as acromio humeral intervals (AHI),lateral extension of the acromion (LEA) and inclination angle of the acromion with the subacromial impingement syndrome (SIS).Methods 151 patients underwent MRI examination of shoulder joints,they were grouped according to age,gender and location of acromion.The differences in age,gender and MR indexes were compared between SIS group and non SIS group.The distribution statuses of SIS in different groups were compared at the same time,the relationships of various MR indexes with SIS were investigated and analyzed.Results There were no statistical differences in age,location distribution,the average shortest AHI value and the thickness of the subacromial bursal effusion between SIS group and non SIS group (P ＞ 0.05).There showed statistical difference in gender between the two groups (P =0.000),and there were more males than females in both groups.The acromion exactly covered the supraspinatus tendon in 79 patients,the average value of LEA in the SIS group was greater than that in the non SIS group,and there showed statistically significant difference between the two groups (P =0.002),the Youden index of LEA was 0.40,the sensitivity was 61％ and the specificity was 79％.The inclination angle of the acromion in the SIS group was smaller than that in the non SIS group,and there was a statistically significant difference between the two groups (P =0.019),the Youden index of the inclination angle of the acromion was 0.18,the sensitivity was 62％ and the specificity was 56％.47 patients in the SIS group had subacromial bursal effusion,51 patients in the non SIS group had subacromial bursal effusion.The thickness of the subacromial bursal effusion in the SIS group was greater than the non SIS group,and there showed statistically significant difference between the two groups (P =0.002),the Youden index of the thickness of the subacromial bursal effusion was 0.34,the sensitivity was 78 ％ and the specificity was 56 ％.Conclusion LEA,the inclination angle of the acromion and the thickness of the subacromial bursal effusion can be used as quantitative MR diagnostic criteria of SIS.The LEA measured by cardiothoracic ratio is simple and easy to use.