多层螺旋CT对阻塞性睡眠呼吸暂停综合征手术前后上气道测量的价值

目的 了解MSCT对评价阻塞性睡眠呼吸暂停综合征(OSAS)患者手术前、后上气道变化及手术疗效的价值.方法 应用16层螺旋CT MPR、CPR及VR等方法测量26例OSAS患者上气道,比较分析手术前、后上气道矢状面重组图像轴面层面咽腔的前后径和面积、腭后区及舌后区最小面积层的各径线和面积及相对位置、软腭悬雍垂最厚处厚度及矢状面上的面积、冠状面CPR图像上最厚左右侧壁厚度、上气道容积;并与多导睡眠(PSG)监测结果进行相关性分析.数据分析应用Paired-Samples t检验或Pearson直线相关分析.结果 与术前比较,手术后患者在矢状面重组后再行轴面重组图像上,上气道腭后区下部(第4层)前后径及面积明显增加[前后径手术前为5.9 mm,手术后为12.8 mm;面积手术前为51.0 mm~2,手术后为275.0 mm~2,t值分别为-5.506、-5.011,P值均<0.05].上部(第2层)显著减小[前后径手术前为14.8 mm,手术后为9.2 mm;面积手术前为241.0 mm~2,手术后为128.0 mm~2,t值分别为2.867、3.087,P值均<0.05].舌后区(第7层)术后前后径明显减小[手术前为12.7mm,手术后为10.3 mm,t=3.718,P<0.05].最小面积层腭后区左右径、面积手术后显著增加[左右径手术前为6.4 mm,手术后为10.9 mm;面积手术前为33.0 mm~2,手术后为76.0 mm~2,t值分别为-3.413、-2.216,P值均<0.05].临床治愈的9例OSAS患者手术前、后的CT测量结果:应用矢状面重组后再行轴面重组方法测量,9例手术治愈患者(术后呼吸暂停指数(AHI)≤5次/h)腭后区最小面积层面积、前后径及左右径均较术前明显增大[面积手术前为41.0 mm~2,手术后为76.0 mm~2,前后径手术前为4.6 mm,手术后为6.6 mm;左右径手术前为8.3 mm,手术后为13.6 mm;t值分别为-4.932、-7.308、-4.320,P值均<0.05].结论 MSCT的MPR、CPR及VR等重组方法,能较好评估OSAS患者上气道,不仅可以很好地显示解剖结构的变化,也可能提示继发的功能变化.最小面积层相应径线增大可能是评价手术有效的很有意义指标之一.术后腭后区上部可能存在的狭窄需引起临床医师注意.

Evaluation of the upper airway measurements by multi-slice CT before and after operations in obstructive sleep apnea syndrome patients

Objective To evaluate the changes of the upper airway of the patients with obstructive sleep apnea syndrome (OSAS) before and after operations and to know the effects of operations by MSCT. Methods The upper airway dimensions of 26 patients with OSAS were measured on multiplanar reformatted (MPR), curved-planar reformatted (CPR), volume rendering(VR) images of 16-slice spiral CT. The measurements include the anteroposterior calibres and the areas on the reformatted axial images on the pharyngeal cavity levels, the calibres and the minimum areas in retropalatal and retroglossal regions, the areas of the soft palate and uvula on the reformatted sagittal view with maximum thickness, the maximum wall thickness of the right and left the upper airway on the coronary images, the volume of the upper airway before and after the operations. The measurements were correlated with the polysomnography (PSG) records. The data were analyzed paired-samples t-test and Pearson correlations. Results By comparison, the anteroposterior calibres and the cross-sectional areas on the reformatted axial view of the lower retropalatal region (slice 4) of the upper airway increased significantly after operations. The anteroposterior diameter increased from 5. 9 mm before operations to 12.8 mm after operations, where t = - 5.506, P < 0.05. The areas increased from 51.0 mm~2 before operations to 275.0 mm~2 after operations, where t = -5.011, P <0.05. In the higher retropalatal region (shce 2) of the upper airway, the anteroposterior diameter decresased from 14.8 mm before operations to 9.2 mm after operations, where t = 2.867, P < 0.05. The areas decreased from 241.0 mm~2 before operations to 128.0 mm~2 after operations, where t = 3.087, P < 0.05. The anteroposterior calibres of retroglossal region (slice 7) decreased from 12.7 mm before operations to 10.3 mm after operations,where t = 3.718, P <0.05. The L-R calibres and the minimum areas of of retropalatal increased significantly from 6.4 mm, 33.0 mm~2 before operation to 10.9 mm, 76. 0 mm~2 after operation, where t = -3.413, -2. 216, respectively and P < 0.05. Of the 9 cases whose apnea and hypopnea index (AHI) ≤5 events/hour after operations, the minimum areas of retropalatal region, the anterio-posterior diameter, L-R calibres increased significantly. The areas increased from 41.0 mm2 before operations to 76.0 mm~2 after operations, were t = -4. 932, P <0.05. The anteroposterior calibres increased from 4.6 mm before operations to 6.6 mm after operations, where t = - 7. 308, P < 0.05. The L-R calibres increased from 8.3 mm before operations to 13.6 mm after operations, where t = - 4.320, P < 0.05. Conclusions MPR、CPR、VR of MSCT can evaluate the not only the morphology but the function changes of the upper airways on the OSAS patients. The increasing of the minimum cross-sectional area may be one of the important indications for evaluating operations. The narrowing of the higher retropalatal region of the upper airway after operations should be an alert to the clinicians.