Detection of intracavitary uterine pathology using offline analysis of three-dimensional ultrasound volumes: interobserver agreement and diagnostic accuracy.

OBJECTIVE: To estimate the diagnostic accuracy and interobserver agreement in predicting intracavitary uterine pathology at offline analysis of three-dimensional (3D) ultrasound volumes of the uterus. METHODS: 3D volumes (unenhanced ultrasound and gel infusion sonography with and without power Doppler, i.e. four volumes per patient) of 75 women presenting with abnormal uterine bleeding at a 'bleeding clinic' were assessed offline by six examiners. The sonologists were asked to provide a tentative diagnosis. A histological diagnosis was obtained by hysteroscopy with biopsy or operative hysteroscopy. Proliferative, secretory or atrophic endometrium was classified as 'normal' histology; endometrial polyps, intracavitary myomas, endometrial hyperplasia and endometrial cancer were classified as 'abnormal' histology. The diagnostic accuracy of the six sonologists with regard to normal/abnormal histology and interobserver agreement were estimated. RESULTS: Intracavitary pathology was diagnosed at histology in 39% of patients. Agreement between the ultrasound diagnosis and the histological diagnosis (normal vs abnormal) ranged from 67 to 83% for the six sonologists. In 45% of cases all six examiners agreed with regard to the presence/absence of intracavitary pathology. The percentage agreement between any two examiners ranged from 65 to 91% (Cohen's κ, 0.31-0.81). The Schouten κ for all six examiners was 0.51 (95% CI, 0.40-0.62), while the highest Schouten κ for any three examiners was 0.69. CONCLUSION: When analyzing stored 3D ultrasound volumes, agreement between sonologists with regard to classifying the endometrium/uterine cavity as normal or abnormal as well as the diagnostic accuracy varied substantially. Possible actions to improve interobserver agreement and diagnostic accuracy include optimization of image quality and the use of a consistent technique for analyzing the 3D volumes.

Effect of gel-instillation sonography on Doppler ultrasound findings in endometrial polyps.

OBJECTIVE: Saline infusion sonohysterography has been reported to suppress the color signal within the endometrium at color or power Doppler evaluation. The aim of this study was to evaluate if gel-instillation sonography (GIS) affects the power Doppler signal in patients with endometrial polyps. METHODS: Ultrasound volumes of the uterus, obtained by three-dimensional ultrasound imaging of 25 women with histologically confirmed endometrial polyps, were assessed offline by six gynecologists with a special interest in gynecological ultrasound. Each woman contributed four volumes: one gray-scale volume and one power Doppler volume before GIS, and one gray-scale volume and one power Doppler volume at GIS. Power Doppler features before and after gel infusion were compared. RESULTS: At unenhanced ultrasound a pedicle artery was seen in 27-46% of cases, whereas, after gel infusion the examiners reported a pedicle artery in 30-46% of cases (Exact McNemar's test P-values ranged from 0.50 to 1.00). The level of agreement between unenhanced ultrasound and GIS ranged from 59 to 91% (Cohen's kappa values ranged from 0.17 to 0.79). There was no tendency for a pedicle artery to be identified less often at GIS than before gel instillation. CONCLUSION: Gel infusion does not affect the power Doppler signal in patients with endometrial polyps.

Clinical implications of intra- and interobserver reproducibility of transvaginal sonographic measurement of gestational sac and crown-rump length at 6-9 weeks' gestation.

OBJECTIVES: To assess intra- and interobserver agreement of routinely performed measurements-crown-rump length (CRL) and mean gestational sac diameter (MSD)-for assessing the likelihood of miscarriage in the first trimester of pregnancy using transvaginal sonography. METHODS: A cross-sectional study of CRL and gestational sac measurements in first-trimester pregnancies was conducted in a fetal medicine referral center with a predominantly Caucasian population. Gestational age ranged from 6 to 9 weeks. All patients underwent a transvaginal ultrasound examination using a high-resolution ultrasound machine. Two measurements of CRL and measurements of three diameters of the gestational sac were obtained by two observers. Agreement within and between observers for CRL and between observers for MSD was analyzed using 95% prediction intervals, Bland-Altman plots with 95% limits of agreement and the intraclass correlation coefficient (ICC). RESULTS: In total 54 patients were included in the study, with measurements obtained by both observers in 44 of these. Intra- and interobserver ICCs were high for CRL measurements, with values of 0.992 and 0.993 for intraobserver agreement and 0.993 for interobserver agreement. For the MSD, the interobserver ICC was 0.952. Limits of agreement were ± 8.91 and ± 11.37% for intraobserver agreement of CRL and ± 14.64% for interobserver agreement of CRL. For MSD, the interobserver limits of agreement were ± 18.78%. For an MSD measurement of 20 mm by the first observer, the prediction interval for the second observer was 16.8-24.5 mm. For a CRL measurement of 6 mm, the prediction interval for the second observer was 5.4-6.7 mm. CONCLUSION: For dating purposes, there is reasonable reproducibility of CRL measurements using transvaginal ultrasonography at 6-9 weeks' gestation. When diagnosing miscarriage based on measurements of CRL care must be taken for values close to any decision boundary. The higher interobserver variability that we observed for MSD has implications for the diagnosis of miscarriage based on this measurement in the absence of a visible embryo or yolk sac.

Java-based framework for processing and displaying short-echo-time magnetic resonance spectroscopy signals.

Magnetic resonance spectroscopy (MRS) can be used to determine in a non-invasive way the concentrations of certain chemical substances, also called metabolites. The spectra of MRS signals contain peaks that correspond to the metabolites of interest. Short-echo-time signals are characterized by heavily overlapping metabolite peaks and require sophisticated processing methods. To be useful in a clinical environment tools are needed that can process those signals in an accurate and fast way. Therefore, we developed novel processing methods and we designed a freely available and open-source framework (http://www.esat.kuleuven.ac.be/sista/members/biomed) in which the processing methods can be integrated. The framework has a set of abstract classes, called hot spots, and its goal is to provide a general structure and determine the control flow of the program. It provides building blocks or components in order to help developers with integrating their methods in the framework via a plug-in system. The framework is designed with the unified modeling language (UML) and implemented in Java. When a developer implements the framework he gets an application that acts like a simple and user-friendly graphical user interface (GUI) for processing MRS data. This article describes in detail the structure and implementation of the framework and the integration of our processing methods in it.

The influence of weight gain patterns in pregnancy on fetal growth using cluster analysis in an obese and nonobese population.

OBJECTIVE: Excessive weight gain during pregnancy has an important influence on fetal growth and on weight development in future generations. DESIGN AND METHODS: A prospective cohort study of 325 obese and nonobese Caucasian women with naturally conceived, singleton pregnancies was performed. They were followed up until delivery for maternal weight gain and for fetal growth with ultrasound-based weight estimations and final birth weight. Using cluster analysis distinct profiles of maternal weight gain during pregnancy were obtained. Longitudinal regression analysis was performed to investigate the relationship of the maternal weight gain profile and BMI on fetal growth and final birth weight. RESULTS: Cluster analysis revealed four discernable maternal weight gain profiles: 12 cases (3.7%) ended up at their starting weight or decreased in weight (cluster 1), 16 cases (4.9%) who slightly increased in weight (maximum 4 kg) as compared to their initial weight (cluster 2), 114 cases (35.1%) who gained between 4 and 12 kg in weight (cluster 3), and 183 cases (56.3%) who showed the largest weight gain: more than 12 kg (cluster 4). There were statistically significant differences in fetal growth associated with weight gain cluster, which became apparent late in the second trimester and increased toward the end of pregnancy. Maternal BMI and maternal weight gain profile were independent predictors of fetal growth and birth weight. CONCLUSIONS: Therefore, the conclusion is that the cluster analysis permits to discern four gestational weight gain (GWG) patterns in obese and nonobese subjects and that both maternal BMI and maternal weight gain pattern during pregnancy positively influence fetal growth and birth weight.