High-resolution Ultrasound Equipment Research Articles

Role of ultrasound‑guided fine‑needle aspiration cytology combined with thyroid peroxidase and thyroglobulin antibodies in evaluating cervical lymph node metastasis in thyroid cancer.

The present study was designed to explore the role of ultrasound-guided fine-needle aspiration (FNA) cytology combined with thyroid peroxidase antibody (TPO-Ab) and thyroglobulin antibody (Tg-Ab) in evaluating cervical lymph node metastasis in thyroid cancer. The aim was to propose more effective diagnostic strategies for cervical lymph node metastasis in patients with thyroid cancer. Firstly, the present retrospective case-control study selected 294 patients with thyroid cancer treated at Changzhou Second People's Hospital (Changzhou, China). High-resolution ultrasound equipment was used for ultrasound and FNA examinations. Additionally, a retrospective analysis of the patient's comprehensive thyroid function tests, including TPO-Ab and Tg-Ab levels, was conducted. Subsequently, univariate and multivariate logistic regression models were employed to analyze the association between various factors and cervical lymph node metastasis. The overall diagnostic accuracy of the model was evaluated using the receiver operating characteristic curve and its area under the curve. Finally, the performance of the diagnostic model was quantitatively assessed through calculating sensitivity, specificity, positive predictive and negative predictive values. According to the experimental results, sex, tumor stage and the levels of thyroid autoantibodies were associated with the risk of cervical lymph node metastasis in thyroid cancer. Moreover, ultrasound features, such as cystic lesions, loss of hilum of the lymph nodes, abundant vascular supply, heterogeneous echo and microcalcification were also closely related to cervical lymph node metastasis. Logistic regression analysis also showed that tumor stage, serum levels of TPO-Ab and Tg-Ab, and cystic lesions were independent predictors of cervical lymph node metastasis. Furthermore, the combined use of ultrasound, FNA, TPO-Ab and Tg-Ab significantly improved diagnostic sensitivity and specificity. Overall, ultrasound-guided FNA combined with TPO-Ab and Tg-Ab may have a significant role in the evaluation of cervical lymph node metastasis in thyroid cancer. This combined diagnostic approach could significantly enhance diagnostic accuracy, providing a more effective strategy for the clinical management of cervical lymph node metastasis in thyroid cancer.

Ultrasonography Combined with Blood Biochemistry on the Early Diagnosis of Diabetic Kidney Disease.

Objective Diabetic kidney disease (DKD) has been well recognized as a microvascular complication of diabetes mellitus. Perfusion of intrarenal arteries is closely related with development of DKD. The aim of the present study was to investigate relation of ultrasonography performance of intrarenal arteries and grade of DKD. Methods From May to December at 2021, a total of 54 DKD patients and 36 non-DKD cases were recruited. Ultrasonography performance of intrarenal and arteries at lower extremity was examined by high-resolution ultrasound diagnostic equipment; maximum (Vsmax) as well as minimum (Vdmin) blood velocity of arteries were recorded, and resistance index (RI) of arteries were calculated. Blood routine and biochemical parameters were determined from clinical laboratory of our hospital. Results According to eGFR grading, 42.50% of the 54 DKD cases are at Grade 1, and 18.52%, 11.11%, 9.26%, and 18.52% cases were at Grade 2, 3a, 3b, and 4-5, respectively. Blood urea and creatinine were significantly positively related with progress of DKD, while level of Hb was negatively related with DKD. By ultrasonography; we found that Vsmax and Vdmin of main renal artery (MRA), segmental renal artery (SRA), and interlobular renal artery (IRA) were significantly reduced compared with healthy cases; IR of the above arteries was dramatically elevated, and changes of the above data were more obvious than that of lower extremity. Vdmin of MRA, SRA, and IRA was negatively related with grading of DKD, while RI was positively related with the grading. Converging from RI and level of Hb, we found that the level of Hb is positively related with healthy status of the kidney, while RI of the arteries is negatively with that. Conclusions Resistance index (RI) of intrarenal arteries, obtained from ultrasonography combining with level of hemoglobin (Hb), is the predictor of progress of DKD.

Intima-Media Thickness Measurements of the Common Carotid Artery in Patients with Central Serous Chorioretinopathy: A Case-Control Study.

Purpose To evaluate the intima-media thickness (IMT) of the left and right common carotid arteries (CCA) as an indicator of subclinical atherosclerosis in patients with central serous chorioretinopathy (CSCR). Methods This was a case-control study involving patients with CSCR and a matched healthy control group. The mean and difference of the left and right CCA IMT were determined and compared between the two groups using carotid duplex high-resolution B-mode ultrasound equipment. Results The study enrolled 32 CSCR patients (68.8% female, mean age 38.22 ± 5.42 years) and 32 controls (65.6% female, mean age 39.56 ± 5.33 years). The difference in common carotid IMT between the right and left sides was significantly greater in the CSCR group than in the control group (p < 0.001). Additionally, according to logistic regression analysis, patients with CSCR had a greater chance of having differences in IMT between the two sides when compared to the control group (OR: 1.29, 95% CI: 1.09–1.52). Conclusion Our findings indicated that in the CSCR group, the difference between the right and left sides of CCA IMT was significantly greater than in the control group.

Communicating with residents about 10years of scientific progress in understanding thyroid cancer risk in children after the Fukushima Dai-ichi Nuclear Power Station accident.

ABSTRACTAfter the Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident in 2011, radiation-related risk of childhood thyroid cancer remains a matter of concern among residents living in areas affected by radioactive plumes. As a countermeasure to that, the Fukushima Prefectural Government—in conjunction with Fukushima Medical University—began the Fukushima Thyroid Examination (FTE) campaign in 2011. As 116 definite or suspected thyroid cancer cases were found after the first round of FTE and the total number of cases was >240 as of June 2020, residents’ concerns have deepened. Some researchers claim that these cases are radiation-induced, while others claim a screening effect (because FTE uses high-resolution ultrasound equipment) and express concern about over-diagnosis. Researchers therefore must address two conflicting issues: one is to elucidate radiation effects on thyroid cancer, which requires continuation of FTE; the other is to solve ethical problems associated with FTE. As to over-diagnosis, surgeons claim that early diagnosis benefits children by reducing the side-effects of treatment and prolonging disease-free survival, while cancer epidemiologists claim that early diagnosis will result in overtreatment without reducing the death rate. ‘To receive FTE or not’ and ‘to stop FTE or not’ are ongoing dilemmas for children (and their parents) and other stakeholders, respectively. To facilitate building a consensus among stakeholders, I overview recent findings about dose reconstruction, the dose–response relationship of thyroid cancer, over-diagnosis, and the natural history of thyroid cancer, all of which contribute to judging the risk–benefit balance of thyroid screening.

Evaluation of Carotid Artery Stenting with Distal Filter Protection Device

Abstract Objectives To assess the use of proximal protection devices in consecutive patients as the preferred means of cerebral embolic protection for primary carotid stenting. Methods and Results This was a prospective single-center study to evaluate the technical and clinical success of proximal protection devices as the first choice for embolic protection in symptomatic (≥ 50%) and asymptomatic (≥ 70%) carotid stenosis. Proximal protection devices were used for embolic protection in 115 consecutive patients. No patients were excluded for anatomical reasons. The filter used was of diameters 6 mm in all cases (Emboshield NAV filter device, Abbotts Healthcare Pvt. Ltd. [Lake Bluff, Il]). In all cases, self-expanding closed-cell designed stent was used (X-act closed-cell self-expanding nitinol carotid-tapered stent, Abbotts Healthcare Pvt. Ltd.). Plaque characterization was done by using real-time high-resolution ultrasound (HR USG) equipment (Aloka Prosound Alpha 7 [Chiyoda, Tokyo, Japan]) using high-frequency linear transducers (&gt; 7 MHz). Follow-up duration was 30 days. Mean age was 61.9 ± 8.27 years. There was male predominance observed in study accounting for 73 out of total 115 studied population. Fifty-six of 115 (48.89%) treated stenoses were symptomatic. Technical success was achieved in 115 of 115 (100%) cases. In both the cases, additional distal filter devices were used. Carotid stenting was successful in 115 (100%) lesions. This study observed higher number of debris in symptomatic and high-risk plaques. This study also observed higher sensitivity, specificity, and accuracy of updated classification for assessing risk of microembolism (captured debris) (sensitivity 73.91%, specificity 95.65%, positive predictive value [PPV] 91.89%, negative predictive value [NPV] 84.62%, accuracy 86.95%). In our study, minor stroke was seen in three (2.61%) patients within 48 hours, and no adverse events were seen within 48 hours to 1 month. Conclusion Proximal protection is a safe method as the first choice for embolic protection. It can be used with a high rate of technical success.

Thyroid nodules in centenarians: prevalence and relationship to lifestyle characteristics and dietary habits.

BackgroundThyroid nodules (TNs) are common thyroid lesions in older population. Few studies have focused on the prevalence of TNs and their relationship to lifestyle characteristics and dietary habits in centenarians. The current study aimed at determining the prevalence of TNs in Chinese centenarians by using high-resolution ultrasound (US) equipment and at investigating its relationship to lifestyle characteristics and dietary habits.Participants and methodsThe current study was part of the China Hainan Centenarian Cohort Study that was conducted in Hainan, an iodine-sufficient region in People’s Republic of China. A total of 874 permanent residents aged ≥100 years (mean age =102.8±2.8 years) without any missing data were included in the analysis.ResultsAmong the participants, 649 of them were detected at least one TN under the US examinations. The overall prevalence rate of TNs was 74.3%. The prevalence of TNs was higher in participants who were women, had hypertension, had diabetes, and were underweight compared with their counterparts. Multivariate logistic regression analyses showed that being female, hypertensive, and diabetic; betel quid consumption; and red meat consumption were independent risk factors, while being underweight and nut consumption were independent protective factors for TNs.ConclusionOur findings indicate that the presence of TNs was highly prevalent in Chinese centenarians, particularly in women. In addition to gender, having hypertension, having diabetes, and being underweight, the presence of TNs was independently associated with betel quid, red meat, and nut consumption. Further prospective studies are warranted to verify these associations in populations from different age strata, races, cultures, and iodine supplementation.

One-step surgical removal of cutaneous melanoma with surgical margins based on preoperative ultrasound measurement of the thickness of the melanoma.

Surgical margins of melanoma vary from 5mm to 1 or 2cm depending on histology thickness (Breslow). This approach usually requires two surgical steps: excisional biopsy and further re-excision according to histology thickness. A previous systematic review showed that measuring melanoma thickness with high-resolution ultrasound imaging equipment correlates well with histological measurement of melanoma thickness. Therefore, we routinely determined tumour sonographic thickness in order to perform surgery as a single step. To determine the proportion of patients who receive one-step surgery with adequate margins based on sonographic measurement of melanoma thickness and identify the reasons for differences between these two measurements. A retrospective series of patients with melanoma, in which thickness was measured by ultrasound (20MHz) from April 2007 to December 2015 prior to surgery. Ninety-nine melanomas were treated, of which 78 were removed in a single step with surgical margins based on sonometric thickness measurements; 71 of these (91%, 95%CI: 82-96) did not require re-excision, five had excessive margins, and two had insufficient margins. The correlation between the histometric and sonometric measurements was good; r=0.88. Significant absolute difference between sonometric and histometric measurements was associated with thickness, ulceration, and size of tumours, based on bivariate analysis. Thickness remained the only significant factor based on multivariate analysis. Measuring the thickness of melanoma with high-resolution ultrasound imaging equipment makes it possible to remove the melanoma in a single step with adequate margins in at least 82% of the cases in routine care.

Ultrasound of the Fetal Veins Part 3: The Fetal Intracerebral Venous System.

The study of the intracerebral venous system in the fetus can only be achieved by means of high-resolution ultrasound equipment with sensitive color Doppler. In the past two decades, there has been a growing interest in the ultrasound examination of the fetal brain with few studies reporting on the brain vasculature during various stages of gestation. In comparison to other fetal venous systems, reports on the assessment of the fetal cerebral venous system are still scarce. This article presents a review on the fetal intracranial venous system with detailed discussions on the anatomy of the superficial and deep cerebral veins. Color Doppler of the main fetal cerebral veins to include the superior sagittal sinus, the straight sinus, the vein of Galen, the internal cerebral veins, the transverse sinuses and others is also discussed. Furthermore, this article highlights abnormal clinical conditions such as aneurysm of the vein of Galen, thrombosis of the dural sinus and variation in the course of some veins such as the straight sinus and falcine sinus. The role of pulsed Doppler examination in normal and growth-restricted fetuses is also discussed.

Prospective evaluation of a protocol for using transabdominal ultrasound to screen for short cervix

We sought to evaluate a recently proposed protocol whereby transabdominal ultrasound of the cervix might be used as a prescreen to select women to undergo or to forgo measurement of cervical length via transvaginal ultrasound (CLvag). This was a prospective cohort study. Measurements of cervical length via transabdominal ultrasound (CLabd) and CLvag were made in women with singleton pregnancy during routine obstetrical ultrasound examination at 18(0/7) to 23(6/7) weeks of gestation. The transabdominal screen was considered positive if CLabd was ≤36 mm with the maternal bladder full or ≤35 mm with the bladder empty, or adequate imaging of the cervix could not be obtained. Sensitivity, specificity, predictive values, and likelihood ratios of a positive screen to detect a short cervix (CLvag ≤25 mm) were calculated. An interim analysis identified several technical problems with CLabd measurements, so the protocol was extensively revised. Under the revised protocol, 1580 women were included. Adequate views of the cervix were obtained via transabdominal imaging in 46% of subjects with the bladder empty and 56% with the bladder full. The correlation between CLabd and CLvag was poor (r = 0.38). Of the 17 patients with a short cervix, 15 had suboptimal transabdominal exams (screen positive) and 2 had CLabd ≤35 mm with bladder empty (screen positive). Sensitivity of the screen was 100% (95% confidence interval, 80.5-100%) but specificity was only 32.2% (95% confidence interval, 29.9-34.6%) and screen positive rate was 66.3%. Several technical problems and limitations of transabdominal imaging of the cervix are shown. Using modern, high-resolution ultrasound equipment, we were unable to adequately image the cervix via transabdominal ultrasound in half the cases. Although we confirmed that a CLabd cutoff value of 35-36 mm is appropriate for detection of short cervix, the technique for measuring CLabd is fraught with technical problems. Practitioners must validate the technique in their own practice before adopting this or similar prescreening protocols. We decided not to adopt this protocol.

Comparative Study of High-Resolution Multifrequency Ultrasound of the Plantar Skin in Patients with Various Types of Hereditary Palmoplantar Keratoderma

Background: High-variable-frequency ultrasound is used as an imaging tool for various cutaneous disorders. We utilized this tool in pachyonychia congenita (PC) patients, who typically present with plantar hyperkeratosis and often severely debilitating pain, compared to patients with epidermolytic palmoplantar keratoderma (EPPK) and mal de Meleda (MDM). Objective: To ascertain the feasibility of ultrasound technology for the diagnosis of PC. Methods: The study included a total of 16 patients, 7 with PC, 5 with EPPK and 4 with MDM, who underwent ultrasound examination of the plantar skin with high-resolution multifrequency ultrasound equipment. Results: Ultrasound scans performed over the proximal and distal plantar foot calluses in PC patients demonstrated hyperechoic dots and lines within the epidermis compatible with hyperkeratosis, engorged varicose veins in the dermis and an anechoic layer interposed between the epidermis and the dermis, corresponding to blister fluid below the calluses. In contrast to PC patients, patients with MDM and EPPK demonstrated no blisters. Conclusion: PC patients, as opposed to a group of patients with MDM and EPPK, displayed subepidermal blistering beneath their calluses. This finding may help in the diagnosis of PC and in partially explaining plantar pain as part of PC symptomatology.

Can impaired decidualization of the endometrium increase the risk of implantation of poor embryos and thereby cause recurrent miscarriage?

Objective: To investigate the effect of differences in endometrial thickness and pattern as visualized with present-day high-resolution transvaginal ultrasound equipment on the outcome of assisted reproductive treatment.Design: Prospective cohort study.Setting: Two large infertility units in university hospitals.Patient(s): The endometrial characteristics of 981 patients during 1,600 assisted reproductive treatment cycles were compared with those of 205 untreated women. In addition, abnormal echogenic patterns of the endometrium were characterized histologically in 44 patients.Intervention(s): None.Main Outcome Measure(s): Pregnancy rates.Result(s): The endometrium was significantly thinner in untreated women and women treated with IUI than in women treated with IVF or intracytoplasmic sperm injection. The exponential proliferation of the endometrium was similar in conception and nonconception cycles. The odds for a successful pregnancy were significantly lower in the presence of a thin endometrium in women treated with IUI but not in women treated with the long stimulation protocol for IVF or intracytoplasmic sperm injection. Singleton pregnancies were more common than multiple pregnancies in patients with thin endometria.Conclusion(s): The pregnancy rates of assisted reproductive procedures are influenced only marginally by the degree of endometrial proliferation, and treatment should not be canceled because of inadequate endometrial thickness.

Prenatal interventions for fetal lung lesions

The widespread availability of high resolution ultrasound equipment and almost universal routine anatomy scanning in all pregnant women in the developed world has lead to increased detection of abnormalities in the fetal thorax. Already in the 1980s, large pleural effusions and significant macrocystic lesions in the fetus were easily detected on ultrasound. However, smaller lung tumours were often missed. Nowadays, fetal medicine centres receive many referrals for evaluation of fetal lung lesions, of which the most common are congenital cystic adenomatoid malformation and bronchopulmonary sequestration. Almost invariably, both the parents and the referring physicians experience anxiety after detection of large lung masses in the fetus. However, the vast majority of the currently detected fetal lung lesions have an excellent prognosis without the need for prenatal intervention. In the small group of fetuses in which the prognosis is poor, almost exclusively those with concomitant fetal hydrops and cardiac failure, several options for fetal therapy exist, often with a more than 50% survival rate. Indications, techniques, complications and outcomes of these interventions will be described in this review.

Fetal echocardiography at 11–13 weeks by transabdominal high‐frequency ultrasound

To assess the accuracy of fetal echocardiography at 11-13 weeks performed by well-trained obstetricians using a high-frequency linear ultrasound transducer. Fetal echocardiography was performed by obstetricians immediately before chorionic villus sampling for fetal karyotyping at 11-13 weeks. Digital videoclips of the examination stored by the obstetrician were reviewed offline by a specialist fetal cardiologist. The obstetrician suspected 95 (95%) of the 100 cardiac defects identified by the fetal cardiologist and made the correct diagnosis in 84 (84%) of these cases. In 54 fetuses, the defect was classified as major and in 46 it was minor. In 767 (86.6%) cases, the heart was normal and in 19 (2.1%) the views were inadequate for assessment of normality or abnormality. A subsequent second-trimester scan in the normal group identified major cardiac defects in four cases. Therefore, the first-trimester scan by the obstetricians and cardiologists identified 54 (93.1%) of the 58 major cardiac defects. A well-trained obstetrician using high-resolution ultrasound equipment can assess the fetal heart at 11-13 weeks with a high degree of accuracy.

Ultrasonographic Evaluation of the Fetal Neural Axis

ABSTRACT The central nervous system is probably the first organ system to be investigated in utero by diagnostic ultrasound. Anencephaly was the first congenital anomaly to be recognized by this technique before viability. Since then, the investigation of the fetal neural axis has steadily remained a central issue of antenatal sonography. Such an interest is explained by a number of reasons. CNS anomalies are frequent and often have a severe prognosis. In many cases they have a genetic background: consequently a large number of couples are at risk and warrant antenatal diagnosis. Modern high resolution ultrasound equipment yields a unique potential in evaluating normal and abnormal anatomy of the fetal neural axis beginning at very early stages of development.

Use of Catheters in the Postoperative Patient

Continuous peripheral nerve block has been shown to be superior to traditional opioid-based analgesia in terms of improved analgesia with reduced sedation, nausea, pruritis, and hospital stay. Because of its safety and efficacy, continuous peripheral nerve block has broad application in ambulatory and pediatric patients. Techniques for continuous peripheral nerve block have advanced significantly in the past decade, particularly as a result of affordable, high-resolution ultrasound equipment that permits rapid and successful administration and results in reduced procedure-related pain, lower dose requirements, and fewer vascular punctures. Continuous peripheral nerve block is associated with some limitations, including infection, neurologic injury, local anesthetic toxicity, and patient falls. The benefits of continuous peripheral nerve block are becoming increasingly relevant in the ambulatory surgery setting where more complex procedures are being performed on an outpatient basis.

Cannulation of the impalpable section of radial artery: preliminary clinical and ultrasound observations

Cannulation of the impalpable section of radial artery: preliminary clinical and ultrasound observations

High‐resolution color Doppler ultrasound of a caliber‐persistent artery of the lip, a simulator variant of dermatologic disease: case report and sonographic findings

Caliber-persistent labial artery (CPLA) is a vascular anomaly in which a primary artery penetrates the submucosa without caliber loss. It presents as an asymptomatic papular lesion, usually on the lower lip, which may be misdiagnosed as a malignant skin tumor and can cause severe bleeding during biopsy or surgery. Development of new high-resolution ultrasound equipment has improved its observation. This study was undertaken to assess the scope of ultrasound for the diagnosis of CPLA. We report a case of a 65-year-old woman with a nodule involving the lower lip, initially misdiagnosed as a malignant skin tumor. Diagnosis was confirmed by high-resolution color Doppler ultrasound using a compact linear probe that generates frequencies of 7-15 MHz. The clinical presentation of the lesion, ultrasound technique, and sonographic findings are described. A current literature review of CPLA diagnosis was performed. Clinical and sonographic images are given as examples. High-resolution color Doppler ultrasound is a reliable noninvasive technique for CPLA diagnosis. It allows direct visualization of this vascular variant in real time without the use of an intravenous contrast agent. It may avoid surgical complications and help in the differential diagnosis. Newer high-resolution equipment allows a clear definition of the cutaneous and muscular layers, as well as the vascularity of the lips.

The endometrial–myometrial junction: a fresh look at a busy crossing

The endometrial–myometrial junction: a fresh look at a busy crossing

Hybrid Endovascular Surgical Repair in Takayasu's Arteritis: Duplex Ultrasound Follow-up

Introduction Takayasu's arteritis (TA), a rare condition occurring primarily in young women, is a granulomatous vasculitis usually affecting the aorta and its branches. Our case report describes the duplex ultrasound findings in a 16-year-old Hispanic woman after a hybrid endovascular procedure. Patient Description TA in this patient was diagnosed in 2005 after a pulsatile neck mass developed on the right side of her neck. To date, she has required four vascular interventions in less than 3 years. The first procedure was an aortic root, ascending aorta and aortic arch replacement with Dacron graft replacement of the left common carotid and innominate arteries. She then developed a pseudoaneurysm in the distal left common carotid artery replacement graft, which was excluded with a stent-graft. The third procedure was a balloon angioplasty of an anastomotic stenosis of the aorto-innominate artery graft. This, however, recurred and there was also a small anastomotic pseudoaneurysm at this site. Revascularization was complicated by the fact that the left subclavian artery was occluded, with reversed flow in the left vertebral artery. Consequently, preservation of antegrade flow in the right vertebral artery was a priority. Transposition of the right common carotid artery to the subclavian artery with placement of a balloon expandable stent graft from the aortoinnominate artery graft into the subclavian artery (proximal to the vertebral artery) was performed. Methods All available imaging exams and operative reports were reviewed. Bilateral carotid duplex evaluation in addition to duplex examination of all bypasses and the distal native arteries were performed using high resolution ultrasound equipment and probes of varying frequency. Results Normal caliber wall thickness was identified in bilateral common carotid arteries. No evidence of intimal hyperplasia could be detected in stented areas. All open surgical or endovascular repair sites were well visualized, with the exception of only the proximal most innominate artery bypass graft and the aortic arch. Primarily retrograde left vertebral artery flow feeds the left subclavian artery. There was no evidence of restenosis or pseudoaneurysm formation. Discussion Long-term follow-up of the patient with TA after open surgical or endovascular procedures is extremely important because of the chronic nature of the disease process. Duplex ultrasound is a safe, effective adjunct to the standard radiologic arsenal usually used to follow these high-risk patients.

Thickness of fetal membranes: a possible ultrasound marker for preterm delivery

To evaluate whether measurement of the thickness of the fetal membranes by high-resolution ultrasound is a useful marker to predict preterm delivery. One hundred and fifty-eight women with singleton pregnancies at 18-35 gestational weeks were enrolled consecutively at our referral center for obstetric care and the thickness of their fetal membranes was measured using high-resolution ultrasound equipment. Data were analyzed to determine whether there were significant differences between those delivering at term and those delivering preterm. Receiver-operating characteristics (ROC) curves were used to determine the best cut-off point of membrane thickness for predicting preterm birth. Women who delivered preterm had greater fetal membrane thickness than did those who delivered at term (1.67 +/- 0.27 mm vs. 1.14 +/- 0.30 mm, P < 0.0001). For the best cut-off indicated by ROC curve analysis (1.2 mm), the sensitivity and specificity for predicting preterm birth were 100% (95% CI, 80.3-100) and 69.5% (95% CI, 61.2-77.0), respectively, and positive and negative likelihood ratios were 3.3 and 0.0, respectively. Sonographic measurement of fetal membrane thickness could be helpful in the prediction of preterm delivery.