梁耀園，馬小燕，黃苑銘，曹建法

(廣東省婦幼保健院超聲診斷科，廣東廣州510010)

三維超聲OmniView在妊娠早期診斷鼻骨缺失的臨床價值

梁耀園，馬小燕，黃苑銘，曹建法

(廣東省婦幼保健院超聲診斷科，廣東廣州510010)

目的探討三維超聲OmniView在早孕期診斷胎兒鼻骨缺失中的應(yīng)用價值。方法選取300例早孕期來我院行常規(guī)超聲檢查的孕婦，按胎兒頭臀徑分為四組，分別為45～54 mm組65例、55～64 mm組74例、65～74 mm組85例、75～84組76例，應(yīng)用二維及三維超聲OmniView對其鼻骨進(jìn)行觀察及圖像分析，對比各組間鼻骨的顯示率，并重點對鼻骨缺失者進(jìn)行圖像分析。結(jié)果①各組三維超聲OmniView對胎兒鼻骨的顯示率均高于二維超聲，除55～64 mm組(顯示率相同)外，各組兩者比較差異無統(tǒng)計學(xué)意義(P＞0.05)；②三維OmniView對胎兒鼻骨的總顯示率稍高于二維超聲，但兩者比較差異無統(tǒng)計學(xué)意義(P＞0.05)。其中6例二維超聲在顏面正中矢狀面未探及鼻骨，三維超聲OmniView可通過顏面部正中矢狀面描畫解剖線，獲取鼻后三角冠狀切面和其相垂直的橫斷切面，顯示了胎兒鼻骨。另外7例二維超聲及三維OmniView均未顯示胎兒鼻骨，診斷為鼻骨缺失。結(jié)論三維超聲OmniView操作簡單，能在二維超聲的基礎(chǔ)上提供更多鼻骨的診斷信息，減少對操作者技術(shù)和經(jīng)驗的依賴，為妊娠早期診斷鼻骨缺失提供了新的思路和方法，是二維超聲檢查的重要補(bǔ)充。

三維超聲；OmniView；胎兒；鼻骨缺失

觀察胎兒鼻骨是產(chǎn)前超聲診斷胎兒畸形的重要組成部分，尤其是妊娠早期鼻骨缺失與多種異常呈密切相關(guān)性，特別和非整倍體胎兒染色體異常的關(guān)系密切，其對診斷21-三體綜合征具有重要意義[1-3]。一直以來，采用二維超聲診斷鼻骨缺失是以胎兒顏面的正中矢狀面為最佳診斷切面，憑此切面診斷鼻骨發(fā)育不良或缺如。但當(dāng)胎兒體位不配合，無法獲取顏面正中矢狀面時，則需要其他切面做補(bǔ)充，而鼻后三角切面被認(rèn)為是最有效的補(bǔ)充切面[4]，但由于受胎位及檢查者技術(shù)和經(jīng)驗的影響，往往二維超聲較難顯示鼻后三角切面。三維超聲OmniView(自由解剖成像)是一種新的三維超聲后處理技術(shù)，可對容積數(shù)據(jù)任意方向和角度進(jìn)行切割，所獲圖像是經(jīng)過切割線且垂直于A的平面。因而只要有完整的容積數(shù)據(jù)就能獲取任意方向和角度的平面，這樣就大大方便了檢查者對于在二維超聲上相對難顯示的切面進(jìn)行顯像觀察[5-6]。目前國內(nèi)外研究應(yīng)用三維超聲OmniView對早孕期胎兒鼻骨缺失的研究較少，因此本研究應(yīng)用三維超聲OmniView對孕早期胎兒鼻骨進(jìn)行成像觀察，比較分析其和二維超聲對鼻骨的顯示率，并對鼻骨缺失胎兒圖像觀察和分析，探討其評價妊娠早期胎兒鼻骨缺失的應(yīng)用價值。

1 資料與方法

1.1 一般資料選取2013年1～12月妊娠早期在我院行產(chǎn)前超聲篩查的孕婦300例，既往無不良妊娠史，胎兒頭臀徑(Crown rump length，CRL)45～84 mm，孕婦年齡19～39歲，中位年齡33歲，均為單胎妊娠。根據(jù)胎兒CRL分為：45～54 mm組65例、55～64 mm組74例、65～74 mm組85例、75～84組76例。所有孕婦均追蹤至出生后3個月內(nèi)情況，對選擇終止妊娠者隨訪引產(chǎn)后外觀情況和病理尸解結(jié)果。

1.2 儀器與方法

1.2.1 儀器采用GE Voluson E8三維超聲診斷儀(使用實時4D容積探頭，經(jīng)腹部容積探頭頻率3～6 MHz，經(jīng)陰道容積探頭頻率為6～12 MHz)。

1.2.2 方法先進(jìn)行常規(guī)篩查，依次掃查胎兒頭顱、顏面、胸部、腹部、四肢及臍帶、胎盤及羊水，測量CRL和頸項透明層(Nuchaltranslucens，NT)、胎盤厚度及羊水深度。接著啟動三維超聲掃描模式，調(diào)整取樣框大小并將取樣框置于胎兒顏面部，選擇合適的掃查角度后，按RUN鍵經(jīng)顏面矢狀切面進(jìn)行容積數(shù)據(jù)采集，并將獲取的三維容積數(shù)據(jù)存入硬盤，如圖像不滿意或胎兒運動明顯時，囑孕婦改變體位或適當(dāng)活動后再重新采集，直至獲取滿意的完整容積數(shù)據(jù)。接著以顏面部矢狀面為參考A平面，激活容積對比成像(Volume contrast imaging，VCI)功能，厚度為1～2 mm，以改善容積對比分辨力。將圖像調(diào)整至水平左向顏面正中矢狀切面，使用2D偽彩模式，調(diào)節(jié)亮度及對比度，使圖像清晰，對比分明。啟用三幅圖顯示模式，在A平面上沿上額骨水平畫第1線(黃線)，顯示鼻后三角冠狀面。沿上腭水平部垂直第1線畫第2線，顯示鼻骨的橫斷面，見圖1。

圖1 正常胎兒鼻骨的三維超聲冠狀切面及橫切面

1.3 統(tǒng)計學(xué)方法采用SPSS13.0統(tǒng)計軟件進(jìn)行數(shù)據(jù)分析，計數(shù)資料采用χ2檢驗，以P＜0.05為差異有統(tǒng)計學(xué)意義。

2 結(jié)果

2.1 二維超聲與三維OmniView對早孕期鼻骨的顯示率由表1可知胎兒頭臀徑于45～84 mm各個組間，兩者對于鼻骨的顯示率差異無統(tǒng)計學(xué)意義(P＞0.05)。三維OmniView對鼻骨的總顯示率為97.7% (293/300)稍高于二維超聲的95.7%(287/300)，但兩者比較差異無統(tǒng)計學(xué)意義(P＞0.05)。

表1 二維超聲與三維OmniView對早孕期鼻骨的顯示率[例(%)]

2.2 超聲診斷及隨訪情況300例胎兒中，其中6例二維超聲在顏面正中矢狀切面未探及鼻骨，并由于孕婦腹壁脂肪厚、胎動頻繁等因素?zé)o法獲取其他鼻骨切面，但可在胎兒顏面部正中矢狀面獲取容積數(shù)據(jù)后，通過三維OmniView描畫解剖線，獲取鼻后三角冠狀切面和其相垂直的橫斷切面而顯示鼻骨(圖1)。另外7例二維超聲及三維OmniView均未顯示胎兒鼻骨(圖2和圖3)，診斷為鼻骨缺失。其中4例NT測值增厚(1例合并頸部淋巴管水囊瘤和全身皮膚水腫，行染色體檢查為21-三體；2例合并顱腦發(fā)育異常；1例合并NT測值增厚，隨訪家屬告知染色體異常并于當(dāng)?shù)匾a(chǎn)，出生后證實)；1例(NT：2.4 mm)于12周超聲無發(fā)現(xiàn)其他異常，于24周在我院Ⅲ級超聲檢查診斷為葉狀全前腦、唇裂合并腭裂、鼻骨缺失、單臍動脈；2例除鼻骨缺失外超聲并無發(fā)現(xiàn)異常，其中1例染色體檢查為46，XN，另一例無異常，小兒出生后除鼻骨扁平并無異常，見表2。

圖2 鼻骨缺失胎兒(CRL：59 mm)的三維超聲冠狀切面及橫切面

圖3 鼻骨缺失胎兒(CRL：57 mm)的三維超聲和正常胎兒冠狀切面對照：示鼻后三角頂點鼻骨缺失

表27 例妊娠早期鼻骨缺失胎兒產(chǎn)前超聲及隨訪檢查結(jié)果

3 討論

鼻骨由額鼻突演化而來，胚胎4周(月經(jīng)齡約6周)時形成，直至9周(月經(jīng)齡約11周)時開始骨化，因此，9周后超聲便可以檢出鼻骨。由于在孕早期鼻骨較小，要診斷鼻骨缺失傳統(tǒng)的二維超聲是以胎兒顏面正中矢狀切面為最佳觀察切面，當(dāng)不能明確鼻骨是否存在的情況下需加選其他切面為輔助[7-11]，但易受胎位及胎動等因素的影響，觀察難度較大，并非能對所有的胎兒都能在此切面上清楚顯示鼻骨，技術(shù)要求高，耗時長。

三維超聲OmniView能對容積數(shù)據(jù)任意方向和角度進(jìn)行切割，從而獲取任意方向和角度的平面，再結(jié)合容積對比成像技術(shù)(VCI)，通過增強(qiáng)二維超聲中相似結(jié)構(gòu)和組織對比度，減少圖像的斑點噪聲，改善分辨力，能更清楚地顯示組織邊緣和內(nèi)部結(jié)構(gòu)[12]，因此兩種技術(shù)結(jié)合處理圖像后可簡化對胎兒鼻骨的超聲檢測，能較快地對胎兒鼻骨缺失做明確的診斷。由本研究可知早孕期三維OmniView對鼻骨的總顯示率(97.7%，293/300)比二維超聲(95.7%，287/300)更高，但兩者并無統(tǒng)計學(xué)意義(P＞0.05)，由此可見其能在二維超聲的基礎(chǔ)上提供更多鼻骨的診斷信息，并減少對操作者技術(shù)和經(jīng)驗的依賴。

此外，妊娠早期鼻骨缺失與多種胎兒異常呈密切相關(guān)性，其中胎兒鼻骨聯(lián)合血清學(xué)檢查結(jié)果是進(jìn)行唐氏綜合征或其他非整倍體畸形風(fēng)險評估的有效指標(biāo)[13-15]。因此，妊娠早期明確診斷鼻骨缺失，有利于臨床盡早對胎兒預(yù)后進(jìn)行評價，指導(dǎo)臨床干預(yù)和對孕婦選擇妊娠結(jié)局具有重要意義。

綜上所述，三維超聲OmniView(自由解剖成像)操作簡便、檢查時間短、靈活，能快速且較好地獲取鼻后三角冠狀切面及其相垂直的鼻骨橫斷切面，能在二維超聲的基礎(chǔ)上提供更多鼻骨的診斷信息，減少對操作者技術(shù)和經(jīng)驗的依賴，為妊娠早期診斷鼻骨缺失提供了新的思路和方法，是二維超聲檢查的重要補(bǔ)充，對臨床盡早評價胎兒預(yù)后及臨床干預(yù)有重要的指導(dǎo)意義。

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Clinical value of three-dimensional ultrasound with OmniView in the diagnosis of absence of nasal bone in early pregnancye.

LIANG Yao-yuan,MA Xiao-yan,HUANG Yuan-ming,CAO Jian-fa.Department of Ultrasound, Guangdong Women and Children's Hospital,Guangzhou 510010,Guangdong,CHINA

ObjectiveTo investigate the clinical application value of OmniView(a new three-dimensional ultrasound technology)in the diagnosis of absence of nasal bone in early pregnancy.MethodsThree hundred pregnant women who underwent routine ultrasound examination in our hospital were enrolled in the study,which were divided into four groups according to the fetal crown rump length∶45～54 mm(65 cases),55～64 mm(74 cases),65～74 mm(85 cases),and 75～84 mm(76 cases),respectively.The nasal bone was observed and analyzed of by applying two-dimensional ultrasound and three-dimensional ultrasound with OmniView.The display rates of nasal bone were compared between groups,and the images of absence of the nasal bone were analyzed.Results①The display rate of each group of OmniView for fetal nasal bone was slightly higher than that of two-dimensional ultrasound(except 55～64 mm group, with the same display rate),but there was no statistically significant difference(P＞0.05).②The total display rate of OmniView on fetal nasal bone was slightly higher than that of two-dimensional ultrasound,with no statistically significant difference(P＞0.05).For two-dimensional ultrasound,6 cases does not show the fetal nasal bone in the median sagittal plane on the face.However,for the 6 cases,OmniView can draw the anatomical lines on referenced facial sagittal plane,obtain the retronasal triangle coronal and its perpendicular to the axial plane,then display the fetal nasal bone.Besides,7 cases did not display the fetal nasal bone in both two-dimensional ultrasound and OmniView,which were diagnosed as nasal bone a bsence.ConclusionThree dimensional ultrasound with OmniView has the advantage of simple operation,and can provide more diagnostic information of the nasal bone based on two-dimensional ultrasound,as well as reduce dependence on operator's skill and experience.It provides a new idea and method for the early diagnosis of absence of nasal bone and serves as an important supplement of two-dimensional ultrasonography.

Three-dimensional ultrasound;OmniView;Fetus;Absence of nasal bone

R714.15

A

1003—6350（2015）12—1768—05

2014-12-01)

基金名稱：廣東省醫(yī)學(xué)科研基金指令性課題項目(編號：c2014013)

梁耀園。E-mail：liangabcde@yeah.net

doi∶10.3969/j.issn.1003-6350.2015.12.0633