1.5 T磁共振关节造影关节囊面积测量及标准化比率在肩关节多向不稳定诊断中的应用价值

目的：利用1.5 T MR关节造影，分析探讨关节囊面积测量及标准化比率在诊断肩关节多向不稳定中的临床应用价值。方法回顾性分析我院2009年1月至2013年2月123例行肩关节造影患者的MR关节造影图像，符合要求47例，其中多向不稳定组10例，对照组（无肩关节不稳定病史）37例，重点观察肩关节纤维囊前下和后下方向上的面积、关节囊总面积、盂唇和盂肱关节骨结构。由两名医师分别独立测量两组病例的关节囊总面积、前下和后下关节囊的面积，计算关节囊标准化比率，并依据关节囊前部附着部位对关节囊进行分型。结果 MR 肩关节造影能清晰显示关节囊的大小和完整性，关节囊前部的附着部位以及关节囊、盂唇的解剖变异。多向不稳定组的关节囊总面积[多向不稳定组（14.76±1.88）cm2，对照组（9.84±2.95）cm2，P＜0.001]，前下关节囊面积[多向不稳定组（4.36±1.16）cm2，对照组（2.61±1.18）cm2，P＝0.001]，后下关节囊面积[多向不稳定组（4.55±1.19）cm2，对照组（3.13±1.33）cm2，P＝0.004]与对照组比较均明显增大；而关节囊标准化比率同样有统计学差异（多向不稳定组2.12±0.37，对照组1.42±0.43，P＜0.001）。结论关节囊总面积、前下、后下关节囊的面积以及关节囊标准化比率与对照组比较均有统计学差异，提示关节囊面积测量对诊断肩关节多方位不稳具有重要的临床意义和实用价值。同时关节囊标准化比率的提出能更精确的提示临床诊断，避免了因性别、个体差异所致误差。

The value of diagnosis of shoulder multidirectional instability with 1.5T MR arthrography using capsul ar area and normalized ratio analysis

Objective The purpose of this study was to evaluate diagnosis of 1.5T MR arthrography technique for multidirectional instability using capsular area and normalized ratio analysis. Methods We retrospectively reviewed 123 shoulders that had undergone MR arthrography （January 2009 to February2013）. Of these, 47shoulders were included in the present study. All cases have received 1.5T MR arthrography examination. These shoulders were divided into two groups： the MDI group comprised 10 shoulders with atraumatic multidirectional shoulder instability, and the control group comprised 37 shoulders with no instability. The emphasis was focused on the fibrous capsule size, the labrum shape, and glenohumeral ligaments and the rotator cuff. Two independent observers measured the capsular area, anterorinferior and posteroinferior capsular areas and normalized ratio in the two groups using MR arthrography. Also, the type of capsular attachment at the mid-glenoid level was evaluated. Results The capsule area was increased in patients with multidirectional instability versus controls [MDI group （14.76±1.88）cm2, control group （9.84±2.95）cm2, P＆lt;0.001]. The anterorinferior area was increased in patients with multidirectional [MDI group （4.36±1.16）cm2, control group （2.61±1.18）cm2, P＆lt;0.001].The posteroinferior area was increased in patients with multidirectional [MDI group （4.55±1.19）cm2, control group （3.13±1.33）cm2, P=0.004]. Also, the normalized ratio was increased with MDI group [MDI group （2.12±0.37）, control group （1.42±0.43）, P＆lt;0.001]. Conclusions The capsular area, anterorinferior area, posteroinferior area and normalized ratio were significantly greater in the clinically diagnosed MDI patients than in the control. Thus, MR arthrography plays an important role in diagnosis of shoulder multidirectional instability. The joint capsule normalized ratio is more accurate in clinical diagnosis of MDI than the other traditional methods.