Early determination of fetal sex using transvaginal sonography: technique and pitfalls

Transvaginal sonography (TVS) enables sex determination at an early stage of pregnancy. The morphologic features of fetal external genitalia at 13 weeks to 16 weeks, menstrual age, are different from those seen later in pregnancy; therefore an attempt to determine fetal gender at this early stage by the same criteria as those used later is hazardous, especially for determining the male sex. The main diagnostic criteria for male gender determination by TVS are the "dome" sign representing the sonographic visualization of the fetal scrotum, the cranially directed phallus, and the longitudinal raphe at the base of the penis. The diagnostic criteria for female gender are the 2 or 4 parallel lines representing the labial folds and the caudally directed phallus (clitoris). The length of the fetal phallus at this early stage is not diagnostic and may be the main pitfall to the unexperienced sonographer. Between weeks 13 and 14 sex diagnosis was possible in 130/171 pregnancies (76%) in our first 2 years and 188/235 (80%) in our last 2 years of experience. Between weeks 15 and 16 sex diagnosis was possible in 122/139 pregnancies (88%) during our first 2 years and 96.7% (528/546) during the last 2 years of experience. The accuracy rate for fetal male gender identification increased from 91.7% during the first 2 years of TVS experience to 99.7% during the last 2 years of TVS experience, and the accuracy rate for female gender identification, increased from 93.3% to 100%, respectively, applying the above criteria and based on acquired experience of early fetal sex identification by TVS early in gestation. Early and precise determination of fetal sex is possible and might avoid invasive procedures such as amniocentesis.     

Diagnosis of pregnancy-associated uterine venous plexus thrombosis on the basis of transvaginal sonography.

OBJECTIVE: To describe the sonographic signs of uterine venous plexus thrombosis. METHODS: Four pregnant patients had a diagnosis of uterine venous plexus thrombosis in the first half of gestation. The diagnosis was based on transvaginal sonography only in 3 cases, and the fourth had magnetic resonance imaging corroboration. RESULTS: All 4 patients had similar sonographic features of uterine venous plexus thrombosis on transvaginal sonographic examination. The thrombi within the dilated veins were shown as elongated echogenic structures along the lumen that appeared round on transverse views of the affected veins. They showed swinging movements provoked by gentle transducer pressure. Power and color Doppler sonography enhanced the uterine venous plexus thrombosis diagnosis by showing blood flow around the thrombi. There were no signs of thromboembolic disease. Sonographic findings in deep leg veins and iliac veins were normal in all cases. Complete thrombophilia studies did not reveal any abnormalities. The uterine venous plexus thrombosis could not be detected on transabdominal sonography and was shown better by transvaginal sonography compared with magnetic resonance imaging. During 3 months of anticoagulation therapy, the thrombi gradually disappeared in all cases. CONCLUSIONS: Focusing on the pelvic veins while performing a transvaginal sonographic study during pregnancy may reveal important findings, which may have clinical implications. The therapeutic treatment of uterine venous plexus thrombosis is controversial and still empirical.     

胎儿脉络膜囊肿的临床价值探讨

目的：探讨胎儿脉络膜囊肿的临床意义。方法;分析1998年7月至2000年7月期间在本院行超声检查并在本院分娩的孕妇2600例。结果：中期妊娠检查时发现胎儿脉络膜囊肿10例,其中单侧9例,双侧1例,均未合并其他超声检查异常,随访至孕28周脉络膜囊肿消失,出生后新生儿无异常发现。结论：中期妊娠超声检查时发现胎儿脉络膜囊肿,应检查有无其他畸形,合并其他畸形时,最好作胎儿染色体检查。     

经阴道超声对宫外孕早期诊断的价值

目的应用经阴道超声检查,诊断宫外孕,评估经阴道超声对宫外孕的早期诊断价值。方法５７例我院住院病人,均经手术病理证实。所有病例均先经腹部超声观察,再经阴道超声检查。结果５７例患,超声诊断为宫外孕５１例,超声诊断符合率为９１％。根据病程的不同时期声像图表现为４种不同类型。结论经阴道超声对宫外孕早期诊断有较高价值,是早期宫外孕简单、有效的首选检查方法。     

经阴道超声在剖宫产瘢痕妊娠早期诊断中的应用

目的探讨经阴道超声(TVS)对剖宫产瘢痕妊娠(caesarean scar pregnancy,CSP)早期诊断的价值及临床意义。方法回顾性分析我院术后确诊为CSP的16例患者的彩色多普勒声像图表现特征、临床转归以及术后结果。结果 TVS诊断CSP的17例患者中,术后病理学证实为CSP者14例,误诊3例;TVS诊断为非CSP的22例患者中,术后病理学证实2例为CSP;TVS诊断CSP的灵敏度为87.5%,特异度为87.0%;术后确诊为CSP的16例患者超声图像表现为单纯孕囊型(6例)、不均质团块型(10例);彩色多普勒血流显像血流信号丰富6例,少许血流信号5例,无血流信号5例。结论 TVS检查有助于对CSP做出早期、准确的诊断及鉴别诊断,对临床治疗方案的选择具有重要意义。     

经阴道超声造影在宫颈癌术前诊断中的临床应用价值研究

目的：探讨经阴道超声造影（ TVS-CEUS）技术在宫颈癌术前诊断中的临床应用价值。方法回顾性分析31例宫颈癌患者的TVS-CEUS术前检查图像,未受累的宫颈、肌层及内膜作为对照,分析宫颈癌瘤体的造影声像图,评估局部病灶的性质、大小范围及术前分期,与术后病理结果进行比较。与正常肌层对比分析宫颈癌病灶TVS-CEUS的时间-增强曲线（ TIC）形态及参数。结果 TVS-CEUS较常规TVS更能清晰显示病灶的边界,获得的病灶大小的测值更接近病理结果。正常子宫肌层与宫颈造影增强模式相同, TIC曲线参数差异无统计学意义（ P＞0.05）,内膜的增强时间稍短,差异有统计学意义（ P＜0.05）。宫颈癌造影增强及消退早于正常肌层,增强强度高于正常肌层,其增强模式为“早进早退”,不同分期的宫颈癌造影增强模式不同。宫颈癌病灶的TIC曲线参数造影剂显影时间（AT）、达峰时间（TTP）、增强时间（ET）、增强强度（EI）、上升斜率（RSR）、半洗出时间（HWOT）、下降早期斜率（HWSR）与对照组比较差异有统计学意义（P＜0.05）,对各参数进行ROC曲线分析得出对宫颈癌诊断能力较强的参数为RSR,界值为1.96 dB/s,灵敏度为100％,特异度为97.6％,Youden指数为97.6％。结论 TVS-CEUS在宫颈癌术前诊断中有较高的临床应用价值。     

Role of transvaginal sonography in the detection of endometriomata

Endometriosis is a common cause of pelvic pain and infertility in young women. Transvaginal sonography is major means for diagnosing ovarian masses. In our study, we scanned 60 patients with endometriomata who underwent laparotomy or laparoscopy. We compared preoperative ultrasonographic diagnosis with histological reports. The sonographic criteria for the diagnosis of endometriomata were (1) cystic structure with low, homogeneous echogenicity and (2) thick cystic wall with regular margins. In 50 patients, sonography suggested an endometrioma. In 47 cases, the diagnosis was correct. The false-positive cases were all caused by cystic teratomas with a homogeneous sonographic pattern. Ten false-negative cases were diagnosed by ultrasonography as functional ovarian cysts (5), teratomas (3), and benign ovarian cystoma (1). Only 1 case of a 5-mm endometrioma was demonstrated by laparoscopy but not by TVS. The sensitivity of TVS for diagnosing endometriomata was 82.4% and specificity 97.7%; the positive and negative predictive values were 94% and 92.8%, respectively. The diagnostic accuracy of TVS was 93%. In our experience, TVS is a very specific means for diagnosing endometriomata when the typical pattern is detected; however, the sensitivity of the technique needs to be improved. © 1995 John Wiley & Sons, Inc.     

Second-trimester sonography and trisomy 18: the significance of isolated choroid plexus cysts after an examination that includes the fetal hands.

OBJECTIVE: To estimate the risk of trisomy 18 with the finding of isolated choroid plexus cysts after a standard sonographic examination that is extended to include the fetal hands. METHODS: Aretrospective chart review was performed on all fetuses with choroid plexus cysts on second-trimester sonographic examinations. When choroid plexus cysts were identified, our standard protocol for fetal evaluation was expanded to include the hands. If no other findings were noted on completion of this examination, the choroid plexus cysts were classified as "isolated." These results were correlated with the presence or absence of trisomy 18 to determine the impact of this approach for the detection of fetuses with this aneuploidy. RESULTS: From March 1990 to the end of 2001, 49,435 fetuses that were subsequently delivered at our hospital were scanned between 16 and 25 menstrual weeks. At least 1 choroid plexus cyst was detected in 1209 fetuses (2.3%), of which 1060 were isolated. No fetuses with isolated choroid plexus cysts had trisomy 18. However, 3 fetuses with trisomy 18 had choroid plexus cysts and abnormal hands as their only abnormal findings. CONCLUSIONS: Fetuses with an apparently isolated finding of choroid plexus cysts can be further evaluated by extending the standard examination to include the hands. If no other findings are identified, the risk of trisomy 18 appears to be low.     

High-frequency transvaginal sonographic examination for the potential malformation assessment of the 9-week to 14-week fetus.

A study was undertaken to evaluate the ability of the high-frequency transvaginal scanning method to consistently image first- and early second-trimester fetal structures, such as body contours, long bones, fingers, face, palate, feet, toes, and the four-chamber view. Ninety-seven low-risk pregnancies were scanned from 9 weeks to 14 menstrual weeks inclusive. Accurate dating was ascertained. The results showed that consistent detection of the respective structures was achieved at the following menstrual ages: sagittal contours at 9 weeks to 10 weeks, long bones at 10 weeks to 11 weeks, fingers at 12 weeks, face and palate at 12 weeks, feet and toes at 13 weeks, and the four-chamber view at 14 weeks. The organs and structures examined could be detected at 9 weeks to 14 weeks inclusive. An increasing number of structure were detected consistently with the increasing menstrual age. The study supports the possibility of searching for specific malformations at or after the menstrual ages mentioned, or performing a more comprehensive malformation evaluation after 13 weeks.     

经阴道彩色多普勒超声检查对异位妊娠的诊断价值

目的探讨经阴道彩色多普勒超声检查（TVCDS）对异位妊娠的诊断价值。方法对手术、病理或保守治疗证实的72例异位妊娠患者的TVCDS图像进行回顾分析。结果附件区出现厚壁环状回声（Donut征）、低回声、或混合回声包块,其中Donut征和类滋养层血流时间流速曲线,是异位妊娠特有的表现,诊断准确率为95舟％。结论TVCDSS对异位妊娠的诊断尤其对早期诊断有重要价值。     

经阴道彩色多普勒超声对子宫内膜癌的诊断价值

目的探讨经阴道彩色多普勒超声检查(TVCDS)对子宫内膜癌的诊断价值。方法对手术、病理或保守治疗证实子宫内膜癌的29例患者的TVCDS图像进行回顾分析。结果 TVCDS术前诊断子宫内膜癌24例,准确率为82.8%;弥漫型19例,符合率为78.9%;局限型5例,符合率为60.0%;血流显示20例,显示率83.3%;阻力指数(RI)0.36-0.57;Ia、Ib期与Ic期比较,血流分级及显示率、RI值具有统计学差异(P0.05)。结论 TVCDS有助于术前诊断子宫内膜癌,为临床选择治疗方案提供了可靠依据。     

Hair as a sonographic marker of ovarian teratomas: improved identification using transvaginal sonography and simulation model.

An in vitro sonographic model was developed to simulate the transvaginal sonographic appearance of hair-containing cystic teratomas of the ovary. Two groups of patients with ovarian teratomas were compared: group A--consisting of 32 patients scanned before the simulation model was used, and group B--consisting of 25 patients in whom the diagnosis of hair-containing ovarian teratomas was made after the simulation model experience. The positive predictive value of transvaginal sonography in correctly diagnosing this type of tumor was 27/32 (84%) in group A and 25/25 (100%) in group B. By using this simple in vitro simulation model, the preoperative diagnosis of ovarian cystic teratomas by transvaginal sonography was made very accurate, enabling prospective planning of the type of operation and its timing.     

Isolated choroid plexus separation on second-trimester sonography: natural history and postnatal importance.

OBJECTIVE: This study was undertaken to investigate the natural history and clinical importance of choroid plexus separation (a > or = 3 mm distance between the choroid plexus and medial wall of the lateral ventricle) as an isolated finding in the second trimester. METHODS: This was a 5-year retrospective review of an ultrasound database, looking for singleton fetuses with a menstrual age of 16 to 26 weeks and a finding of isolated choroid plexus separation. RESULTS: There were 78 cases available for study. The finding of choroid plexus separation was usually transient. Resolution was noted in 37% of the cases that were rescanned within 2 weeks and 71% of the cases that were rescanned more than 2 weeks after the initial diagnosis. Two abnormal karyotypes (trisomy 21 and 47,XXY) and 3 cases with abnormal development not associated with an abnormal karyotype were noted on neonatal follow-up. Cases with abnormal development were quite varied in their presentation. CONCLUSIONS: The finding of isolated choroid plexus separation is usually temporary, resolving in most cases within 4 weeks of the initial diagnosis. Most infants with this finding have no abnormalities. The clinical implication of the lone case of trisomy 21 was limited by a major preexisting risk in this patient. The 3 cases of abnormal development had varying presentations; the causal nature of this association is not yet clear. No trends were noted between the changing choroid plexus appearance with time and abnormal neonatal outcome, but the number of abnormal cases was quite limited.     

脉络丛囊肿胎儿产前超声图像分析

目的探讨脉络丛囊肿胎儿的产前超声声像图特征及产前超声诊断的临床意义。 方法选取2011年1月至2013年7月在成都市妇女儿童中心医院产前超声检出的244例脉络丛囊肿病例随访至产后,对产前超声检查、染色体结果及临床结局进行回顾性分析。 结果（1）单纯脉络丛囊肿232例。60例行染色体检查结果无异常,复查脉络丛囊肿231例27周前消失、1例产前与产后无明显大小变化,232例产后随访0.5~1.5年,婴幼儿发育未见异常。（2）合并轻微超声异常4例。肠管回声增强2例,膜状胎盘1例,胎盘绒毛增生1例,均无染色体异常,脉络丛囊肿均23周前消失,产后随访0.5~1.5年,婴幼儿发育未见异常。（3）合并严重或多发结构异常8例。共18个结构异常包括心脏畸形6例,脐膨出3例,脐带囊肿3例,手足内翻2例,唇裂、膈疝、小下颌、颈部水囊瘤各1例。1例21-三体,1例18-三体,5例无染色体异常,1例未做染色体检查。8例在孕中期引产。 结论单纯或合并轻微超声异常的脉络丛囊肿多数孕27前可消失,胎儿预后良好。少数合并严重或多发的结构异常,染色体异常可能性增加,我们应行系统性或针对性产前超声检查及染色体核型分析。     

单发脉络丛脂肪瘤1例

患者女,76岁.头痛5天,右眼肿4天.心肺腹查体未见异常.神经系统:神志尚清,定向力、记忆力均正常.颅神经正常,双下肢肌力正常.头颅MR:平扫双侧基底节区及额叶脑白质内见多发片状长T1,长T2信号,FLAIR像为高信号,病变边界清楚.右侧脑室后角脉络丛内见小圆形短T1,长T2信号影,约0.6 cm×0.6 cm,信号均匀,边界清晰(图1A、B).T1和T2抑脂序列病变均示病变信号明显减低(图1C、D).MR诊断:双侧基底节区及额叶多发腔隙性脑梗死,右侧脑室脉络丛脂肪瘤.     

Sonography of fetal choroid plexus cysts: detection depends on cyst size and gestational age.

OBJECTIVE: To establish diagnostic criteria for the diagnosis of fetal choroid plexus cysts across gestation. METHODS: Prenatal sonographic images of 166 fetuses without choroid plexus cysts were prospectively collected from 13 weeks to term. Texture characteristics of the choroid plexus regions were analyzed to quantify changes as a function of gestational age. A set of 20 fetal sonographic images with choroid plexus cysts were used to create cyst prototypes (1.5-2.5 mm), which were randomly embedded into normal choroid plexus images from varying gestational ages. A test set of 544 images was created, which included 408 images with choroid plexus cysts and 136 images without choroid plexus cysts. Four observers following a blinded study design evaluated the presence of choroid plexus cysts in the images. The influence of cyst size and gestational age on the detection of cysts was measured with receiver operating characteristic analysis and analysis of variance. Observer agreement was characterized by agreement kappa statistics. RESULTS: Texture analysis indicated greater echo texture heterogeneity at earlier gestational ages. The receiver operating characteristic analysis showed a corresponding decrease in diagnostic accuracy for cyst detection at earlier gestational ages. The cyst detection threshold (area under the receiver operating characteristic curve, 0.8) was 2.4 mm (SE, 0.2 mm) for 13 to 21 weeks' gestation and decreased to 1.9 mm (SE, 0.17 mm) for 22 to 38 weeks' gestation. Average interobserver and intraobserver kappa statistics were 0.37 and 0.53, respectively. CONCLUSIONS: Because of the changing echo texture of the choroid plexus through gestation, choroid plexus cysts must be at least 2.5 mm in diameter for confident diagnosis before 22 weeks' gestation and at least 2 mm after 22 weeks.     

经腹超声联合经阴道超声在判别早孕期胎儿结构异常中的临床价值

目的探讨经腹超声联合经阴道超声在早孕期胎儿结构异常中的应用价值。方法 70例孕9～14周孕妇行经腹超声联合经阴道超声检查,分析胎儿结构异常者的声像图表现。所有结构异常者均经中孕期超声复查或引产后病理证实。结果 70例高危受检孕妇中,超声检出胎儿结构异常者27例,随访25例,失访2例。1例联体双胎漏诊,其余均与超声诊断结果一致;8例为单纯颈项透明层厚度增厚;余19例结构明显异常胎儿中,8例合并染色体异常,7例合并颈项透明层厚度增厚,4例合并水囊瘤。结论经腹超声联合经阴道超声检查提高了胎儿畸形的早期检出,对胎儿畸形早期筛查具有显著的临床价值。规范化及切面标准化是减少漏误诊的重要措施。     

Prognostic value of ultrasound findings of fetal cystic hygroma detected in early pregnancy by transvaginal sonography.

OBJECTIVE: To assess the prognostic value of first and early second trimester transvaginal ultrasound findings of fetal cystic hygroma such as volume, presence of septa and associated fetal anomalies or malformations. DESIGN: A prospective study of fetal cystic hygroma volume detected at 10-15 weeks of gestation by transvaginal scan. SUBJECTS: The study comprised a series of 33 cystic hygromas detected throughout the period March 1994 to March 1998 in 1918 pregnant women. METHODS: The volume of the hygroma and the presence of septa and other associated fetal anomalies or malformations were evaluated and correlated with fetal karyotype, persistence of the hygroma and pregnancy outcome. RESULTS: A volume equal to or greater than 75 mm3 revealed a sensitivity of 66.7% [eight of 12 cases; 95% confidence interval (CI), 34.9-90.1%] for the identification of abnormal fetal karyotype, 72.7% (eight of 11 cases; 95% CI, 39.0-90.4%) for the identification of persistence of the hygroma and 90% (nine of 10 cases; 95% CI, 55.5-99.7%) for identification of an unfavorable outcome of pregnancy. Furthermore, the prognostic value of ultrasound in determining pregnancy and fetal outcome were improved by combining data on the volume of the hygroma and the presence of associated anomalies or malformations. CONCLUSIONS: Measuring the volume of a cystic hygroma proves to be a useful ultrasound prognostic indicator in determining the risk of an associated karyotypic abnormality and adverse fetal and pregnancy outcome. However, due to limited sample size, caution is required in interpretation of the data and further studies are needed.