阻塞性睡眠呼吸暂停综合征患者睡眠状态下低剂量多层螺旋CT研究

Study of low dose and dynamic multi-slice CT about obstructive sleep apnea syndrome in sleeping

目的对睡眠状态下的阻塞性睡眠呼吸暂停综合征(OSAS)患者行低剂量动态多层螺旋CT(MSCT)扫描,分析睡眠状态下气道实际阻塞或狭窄的部位、累及范围及动态变化,以修正静态气道测量的不精确性。方法16例OSAS患者分别行清醒平和呼吸状态下(简称清)与睡眠状态吸气末相(简称吸)、睡眠状态呼气末相(简称呼)下低剂量MSCT扫描,并于睡眠吸气末状态下气道最狭窄处行动态电影扫描。以睡眠吸气末状态下软腭后区(RP)、舌后区(RG)气道最狭窄处及会厌后区(EPG)会厌尖下5 mm处为3种状态下的测量层面,比较3种状态下咽腔各层面的测量值并记录各期相气道最狭窄的具体部位。结果RP区气道最小横截面积(XSA)(M清=47．50 mm2,M呼= 73.00 mm3,M吸=2.00 mm2;Z清呼=2．897,P清呼=0．003;Z清吸=4．192,P清吸<0．01;Z吸呼=4．538, P吸呼<0．01)的测量结果在3种状态下差异均有统计学意义;RP区前后径(AP)(M清=8．00 mm, M呼:9．50 mm,M吸=1．50 mm;Z清呼=1．933,P清呼=0．056;Z清吸=3．720,P清吸<0．01;Z吸呼=4．230, P吸呼<0．01)、左右径(LR)(M清=8．00 mm,M呼=9．00 mm,M吸=1．00 mm;Z清呼=1．210,P清呼= 0．246;Z清吸=4．203,P清吸<0．01;Z吸呼=4．557,P吸呼<0．01)、RP区气道体积(M清=4．00 mm3,M呼= 5．50 mm3,M吸=1．50 mm3;Z清呼=1．576,P清呼=0．125;Z清吸=3．532,P清吸<0．01;Z吸呼=4．077, P吸呼<0．01),RP(M清=7．00 mm,M呼=6．00 mm,M吸=10．50 mm;Z清呼=0．557,P清呼=0．603;Z清吸= 2．541,P清吸=0．011;Z吸呼=2．852,P吸呼=0．004)、RG(M清=5．00mm,M呼=3．00 mm,M吸=9．50 mm; Z清呼=0．747,P清呼=0．482;Z清吸=2．657,P清吸=0．007;Z吸呼=3．075,P吸呼=0．001)区咽后壁至椎体前缘垂直距离的测量结果,睡眠吸气末相与清醒或睡眠呼气末相差异有统计学意义。睡眠状态下动态电影扫描可直观、清晰地显示咽腔的形态学变化。结论(1)睡眠吸气末相对OSAS患者咽腔狭窄或闭塞的CT定位是最精确的,可明显降低清醒状态下测量的假阴性。(2)低剂量MSCT可明显减少对患者的放射剂量。

Objective To perform Low dose dynamic MSCT（multi-slice CT） in sleeping obstructive sleep apnea syndrome （OSAS） patients correcting the imprecise measure values in waking state, and to exactly analyse the location and extension of the dynamic changes about the condition. Methods Sixteen OSAS patients were scanned both in waking and naturally sleeping period （ end phase of inspiration and expiration）. Measured at the narrowest part of the retropalatal （RP） and retroglossal （RG） and 5 nun under the tip of epiglottis at the epiglottal （EPG） at the end period of inspiration in sleeping, respectively, and compared the accurate posnion of the narrowest or occlusive level in 3 phases. All patients were also scanned using cine mode at the narrowest level at the end period of inspiration in sleeping to show the pharyngeal cavity changes during sleep. Results The smallest XSA of RP region （MW = 47. 50 mm^2,Me = 73.00 mm^2, Mi =2. 00 mm^2 ;Zwe =2. 897,Pwe =0. 003 ;Zwi =4. 192,Pwi 〈0. 01 ;Zie =4. 538,Pie 〈0. 01 ） were statistical difference among three phases, furthermore, the AP （the anteroposterior diameter） of RP （Mw = 8. 00 mm, Me = 9. 50 mm, Mi = 1.50 mm ; Zwe = 1. 933,Pwe = 0. 056 ; Zwi= 3.720, Pwi 〈 0.01 ; Zie = 4. 230, Pie 〈 0. 01 ） and LR（ the left-right diameter） of RP region （ Mw = 8.00 mm ,Me = 9. 00 nun ,Mi = 1.00 mm ;Zwe = 1. 210, Pwe=0.246;Zwi=4.203,Pwi 〈0.01;Zie =4.557,Pie 〈0.01） and the volum of RP （Mw =4.00 mm^3,Me =5.50 mm^3,Mi =1.50 mm^3 ;Zwe = 1. 576,Pwe =0. 125;Zwi = 3.532,Pwi 〈0.01 ;Zie = 4. 077,Pie 〈 0. 01 ） and the distance between the posterior wall and anterior vertebra of RP （ Mw = 7.00 mm, Me = 6.00 mm,Mi =10.50 mm;Zwe =0.557,Pwe =0. 603;Zwi =2.541,Pwi =0.011;Zie =2. 852,Pie =0.004） and RG regions （ Mw = 5.00 mm, Me = 3. 00 mm, Mi = 9. 50 mm; Zwe = 0. 747, Pwe = 0. 482 ; Zwi = 2. 657, Pwi =0. O07;Zie = 3. 075, Pie = 0.001 ）, were different between inspiration and expiration of sleeping or awake. The dynamic cine CT scan during sleeping could show pharyngeal change, clearly. Conclusion At the end period of inspiration in sleeping, the location of narrow or obstructive of airway is the most precise and sensitive and the false negative at the waking could be obviously reduced. Low dose MSCT scan reduced exposure and expense.