Three-dimensional Ultrasound Volumes Research Articles

Three-dimensional ultrasound first trimester fetal volume measurement and its relation to pregnancy outcome.

To determine whether fetal volume (FV) measured by three-dimensional (3D) ultrasound was able to detect fetuses at risk of low birth weight (primary outcome) and/or preterm labor (secondary outcome). One hundred pregnant women carrying a singleton living pregnancy who were sure of dates, and had a dating scan, with gestational age between 11 weeks and 13 weeks+6 days coming for routine first trimester nuchal translucency (NT) were examined by both two-dimensional (2D) and 3D ultrasound (Vocal System) for crown-rump length (CRL) and FV then followed up regularly every 4 weeks until 28 weeks then biweekly until 36 weeks then weekly until delivery both clinically and by ultrasound biometry. Eighty-seven cases had a normal outcome, while the remaining 13 cases had either preterm labor (four cases) or low-birth weight (nine cases). FV positively correlated with CRL (P=0.026), gestational age in weeks (P=0.002), neonatal body weight in grams (P=0.018) and neonatal body length at birth (P=0.04). A mean FV of 8.3 mm3 was association with neonatal complications (P=0.045). A cut-off point of 9 mm3 for FV was associated with 100% sensitivity for detection of the date of birth, while a cut-off point of 9.15 mm3 for FV was associated 100% sensitivity for detection of neonatal birth weight. 3D assessment of FV in the first trimester provides an accurate method for predicting pregnancy outcome namely low birth weight and neonatal complications, however, it is a better positive predictor than a negative one.

Relationship between Plasma D-Dimer Concentration and Three-Dimensional Ultrasound Placental Volume in Women at Risk for Placental Vascular Diseases: A Monocentric Prospective Study.

IntroductionThe aim of this study was to correlate placental volumes deduced from three-dimensional ultrasound and virtual organ computer-aided analysis (VOCAL) software with systemic concentrations of D-dimer and soluble endothelial protein C receptor (sEPCR).MethodsThis was a monocentric experimental prospective study conducted from October 2008 to July 2009. Forty consecutive patients at risk of placental vascular pathology (PVP) recurrence or occurrence were included. Placental volumes were systematically measured three times (11–14, 16–18 and 20–22 weeks of gestation (WG)) by two independent sonographers. D-dimers and sEPCR plasma concentrations were measured using ELISA kits (Enzyme Linked ImmunoSorbent Assay).ResultsEleven patients had a PVP. The plasma D-dimer level was positively correlated with placental volume (r = 0.45, p < 0.001). A smaller placental volume and placental quotient was evidenced in women who developed a PVP at the three gestational ages, and the difference was more pronounced during the third exam (20 WG). No obvious correlation could be demonstrated between the development of a PVP and the levels of D-dimer and sEPCR. There was no significant difference in the values of placental volumes measured by the two sonographers.ConclusionThe placenta growth could be a major determinant of the elevation of D-dimer during pregnancy. Consideration of placental volume could allow for modulation of the D-dimer concentrations for restoring their clinical interest.

Automated 3D ultrasound image segmentation to aid breast cancer image interpretation

Segmentation of an ultrasound image into functional tissues is of great importance to clinical diagnosis of breast cancer. However, many studies are found to segment only the mass of interest and not all major tissues. Differences and inconsistencies in ultrasound interpretation call for an automated segmentation method to make results operator-independent. Furthermore, manual segmentation of entire three-dimensional (3D) ultrasound volumes is time-consuming, resource-intensive, and clinically impractical. Here, we propose an automated algorithm to segment 3D ultrasound volumes into three major tissue types: cyst/mass, fatty tissue, and fibro-glandular tissue. To test its efficacy and consistency, the proposed automated method was employed on a database of 21 cases of whole breast ultrasound. Experimental results show that our proposed method not only distinguishes fat and non-fat tissues correctly, but performs well in classifying cyst/mass. Comparison of density assessment between the automated method and manual segmentation demonstrates good consistency with an accuracy of 85.7%. Quantitative comparison of corresponding tissue volumes, which uses overlap ratio, gives an average similarity of 74.54%, consistent with values seen in MRI brain segmentations. Thus, our proposed method exhibits great potential as an automated approach to segment 3D whole breast ultrasound volumes into functionally distinct tissues that may help to correct ultrasound speed of sound aberrations and assist in density based prognosis of breast cancer.

Reliability of the European Society of Human Reproduction and Embryology/European Society for Gynaecological Endoscopy and American Society for Reproductive Medicine classification systems for congenital uterine anomalies detected using three-dimensional ultrasonography

To estimate the inter-rater/intrarater reliability of the European Society of Human Reproduction and Embryology/European Society for Gynaecological Endoscopy (ESHRE-ESGE) classification of congenital uterine malformations and to compare the results obtained with the reliability of the American Society for Reproductive Medicine (ASRM) classification supplemented with additional morphometric criteria. Reliability/agreement study. Private clinic. Uterine malformations (n = 50 patients, consecutively included) and normal uterus (n = 62 women, randomly selected) constituted the study. These were classified based on real-time three-dimensional ultrasound single volume transvaginal (or transrectal in the case of virgins, 4 cases) ultrasonography findings, which were assessed by an expert rater based on the ESHRE-ESGE criteria. The samples were obtained from women of reproductive age. Unprocessed three-dimensional datasets were independently evaluated offline by two experienced, blinded raters using both classification systems. The κ-values and proportions of agreement. Standardized interpretation indicated that the ESHRE-ESGE system has substantial/good or almost perfect/very good reliability (κ >0.60 and >0.80), but the interpretation of the clinically relevant cutoffs of κ-values showed insufficient reliability for clinical use (κ < 0.90), especially in the diagnosis of septate uterus. The ASRM system had sufficient reliability (κ > 0.95). The low reliability of the ESHRE-ESGE system may lead to a lack of consensus about the management of common uterine malformations and biased research interpretations. The use of the ASRM classification, supplemented with simple morphometric criteria, may be preferred if their sufficient reliability can be confirmed real-time in a large sample size.

Appearance of the endometrium at saline contrast sonohysterography in the luteal phase of the menstrual cycle: a prospective observational study.

To describe the ultrasonographic morphology of the endometrium at saline contrast sonohysterography (SCSH) performed in the luteal phase of the menstrual cycle in women 20-38 years of age with regular menstrual cycles. The study included 26 women (median age 33 (range, 20-38) years) with regular menstrual cycles referred for hysterosalpingo-contrast sonography (HyCoSy) as part of infertility work-up (n = 19) or before donor insemination in lesbian couples (n = 7). SCSH and HyCoSy were performed 6-10 days after a positive luteinizing hormone (LH) urinary self-test. Three-dimensional (3D) ultrasound volumes of the uterus were saved with and without saline in the uterine cavity. The results presented are based on offline analysis of the 3D volumes. Median endometrial thickness was 10.4 (range, 6.0-17.3) mm. Twelve (46%; 95% CI, 27-65%) of the 26 women had endometrial folds at SCSH. The number of folds varied between 1 and 6 (median 3). Endometrial thickness was similar in women with and without endometrial folds (median endometrial thickness 10.7 (range, 6.0-17.3) mm vs 10.1 (range, 6.1-14.4) mm; P = 0.257), and the amount of saline in the uterine cavity did not differ between the two groups (median 8.6 (range, 5.2-12.9) mm vs 7.1 (range, 3.2-13.3) mm; P = 0.527). In two women with endometrial folds at two-dimensional (2D) or 3D-SCSH, focal endometrial pathology (polyp) was suspected, but hysteroscopically resected endometrium showed normal histology. One should avoid performing SCSH in the luteal phase of the menstrual cycle, not only because there may be a fertilized ovum in the genital tract but also because endometrial folds are common in this phase and may lead to overdiagnosis of focal endometrial pathology, such as polyps. If, for some reason, SCSH is performed in the luteal phase and the results are equivocal, the procedure should be repeated in the follicular phase.

Interobserver agreement in describing adnexal masses using the International Ovarian Tumor Analysis simple rules in a real-time setting and using three-dimensional ultrasound volumes and digital clips

To estimate the agreement between an expert and a non-expert examiner using the International Ovarian Tumor Analysis (IOTA) simple rules for classifying adnexal masses on real-time ultrasound and when using three-dimensional (3D) ultrasound volumes and digital clips. Forty-two non-consecutive women diagnosed as having an adnexal mass were evaluated by transvaginal power Doppler ultrasound as part of their diagnostic work-up. In each woman, examination was first performed by a non-expert examiner (a trainee) and immediately afterwards by an expert examiner. Both used the IOTA simple rules to describe the mass, blinded to each other's results. After finishing the examination, each examiner classified the mass as benign, malignant or inconclusive, according to the IOTA simple rules. Additionally, the expert recorded a short videoclip and acquired a static 3D volume of each mass, which were subsequently assessed by four trainees in obstetrics and gynecology with different levels of training, who also classified the mass as benign, malignant or inconclusive according to the IOTA simple rules. Agreement was assessed by calculating weighted and standard kappa index values with 95% CI and the percentage of agreement between observers. Agreement between the observers who performed real-time ultrasound examination was good (weighted kappa = 0.76; 95% CI, 0.61-0.90; agreement = 78.6%). Agreement between trainees using videoclips plus 3D volumes was moderate (kappa values ranged from 0.45 to 0.58, depending on pair comparison). Interobserver agreement of the IOTA simple rules for classifying adnexal masses as benign, malignant or inconclusive using real-time ultrasound, between an expert and a non-expert examiner, might be considered good. Agreement using a videoclip plus a 3D volume was moderate for trainees with different degrees of training.

Mapping Cardiac Fiber Orientations from High-Resolution DTI to High-Frequency 3D Ultrasound.

The orientation of cardiac fibers affects the anatomical, mechanical, and electrophysiological properties of the heart. Although echocardiography is the most common imaging modality in clinical cardiac examination, it can only provide the cardiac geometry or motion information without cardiac fiber orientations. If the patient's cardiac fiber orientations can be mapped to his/her echocardiography images in clinical examinations, it may provide quantitative measures for diagnosis, personalized modeling, and image-guided cardiac therapies. Therefore, this project addresses the feasibility of mapping personalized cardiac fiber orientations to three-dimensional (3D) ultrasound image volumes. First, the geometry of the heart extracted from the MRI is translated to 3D ultrasound by rigid and deformable registration. Deformation fields between both geometries from MRI and ultrasound are obtained after registration. Three different deformable registration methods were utilized for the MRI-ultrasound registration. Finally, the cardiac fiber orientations imaged by DTI are mapped to ultrasound volumes based on the extracted deformation fields. Moreover, this study also demonstrated the ability to simulate electricity activations during the cardiac resynchronization therapy (CRT) process. The proposed method has been validated in two rat hearts and three canine hearts. After MRI/ultrasound image registration, the Dice similarity scores were more than 90% and the corresponding target errors were less than 0.25 mm. This proposed approach can provide cardiac fiber orientations to ultrasound images and can have a variety of potential applications in cardiac imaging.

Open fourth ventricle prior to 20 weeks' gestation: a benign finding?

To evaluate the role of the brainstem-vermis (BV) angle in the diagnosis of fetal posterior fossa abnormalities at 15-18 weeks' gestation. We examined retrospectively three-dimensional (3D) ultrasound volumes acquired at 15-18 gestational weeks in fetuses with normal posterior fossa (controls) and in those with cystic posterior fossa. Whether the fourth ventricle appeared open posteriorly in axial views was noted and the BV angle was measured. A detailed follow-up was obtained in all cases. Of the 139 controls, 46 cases were excluded because of inadequate quality of the 3D volumes. Of the 93 remaining normal fetuses, 84 (90.3%) had a closed fourth ventricle and a BV angle < 20°, whereas 9/93 (9.7%) had an open fourth ventricle and a BV angle between 20° and 37°. The study group of 11 fetuses included seven with Dandy-Walker malformation and four with Blake's pouch cyst. In abnormal cases as a whole, the BV angle was significantly increased compared with that in controls (P < 0.0001). However, fetuses with Blake's pouch cyst and normal fetuses with an open fourth ventricle had strikingly similar sonograms: the BV angle was between 20° and 37° and the fourth ventricle appeared open only when viewed using a more steeply angulated scanning plane than that of the standard transcerebellar plane; in fetuses with Dandy-Walker malformation the fourth ventricle was widely open posteriorly, even in the standard transcerebellar view, and the BV angle was > 45°, significantly increased compared both with that in normal fetuses (P < 0.0001) and with that in fetuses with Blake's pouch cyst (P = 0.004). An open fourth ventricle is found in about 10% of normal fetuses at 15-18 weeks' gestation. Measurement of the BV angle is useful in such cases, as a value ≥ 45° is associated with a very high risk of severe posterior fossa malformation.

Initial Validation of a Virtual-Reality Learning Environment for Prostate Biopsies: Realism Matters!

A virtual-reality learning environment dedicated to prostate biopsies was designed to overcome the limitations of current classical teaching methods. The aim of this study was to validate reliability, face, content, and construct of the simulator. The simulator is composed of (a) a laptop computer, (b) a haptic device with a stylus that mimics the ultrasound probe, (c) a clinical case database including three-dimensional (3D) ultrasound volumes and patient data, and (d) a learning environment with a set of progressive exercises including a randomized 12-core biopsy procedure. Both visual (3D biopsy mapping) and numerical (score) feedback are given to the user. The simulator evaluation was conducted in an academic urology department on 7 experts and 14 novices who each performed a virtual biopsy procedure and completed a face and content validity questionnaire. The overall realism of the biopsy procedure was rated at a median of 9/10 by nonexperts (7.1-9.8). Experts rated the usefulness of the simulator for the initial training of urologists at 8.2/10 (7.9-8.3), but reported the range of motion and force feedback as significantly less realistic than novices (P=0.01 and 0.03, respectively). Pearson r correlation coefficient between correctly placed biopsies on the right and left side of the prostate for each user was 0.79 (P<0.001). The 7 experts had a median score of 64% (59%-73%), and the 14 novices a median score of 52% (43%-67%), without reaching statistical significance (P=0.19). The newly designed virtual-reality learning environment proved its versatility and its reliability, face, and content were validated. Demonstrating the construct validity will necessitate improvements to the realism and scoring system used.

An accurate and effective FMM-based approach for freehand 3D ultrasound reconstruction

Freehand three-dimensional ultrasound imaging is a highly attractive research area because it is capable of volumetric visualization and analysis of tissues and organs. The reconstruction algorithm plays a key role to the construction of three-dimensional ultrasound volume data with higher image quality and faster reconstruction speed. However, a systematic approach to such problem is still missing. A new fast marching method (FMM) for three-dimensional ultrasound volume reconstruction using the tracked and hand-held probe is proposed in this paper. Our reconstruction approach consists of two stages: bin-filling stage and hole-filling stage. Each pixel in the B-scan images is traversed and its intensity value is assigned to its nearest voxel in the bin-filling stage. For the efficient and accurate reconstruction, we present a new hole-filling algorithm based on the fast marching method. Our algorithm advances the interpolation boundary along its normal direction and fills the area closest to known voxel points in first, which ensure that the structural details of image can be preserved. Experimental results on both ultrasonic abdominal phantom and in vivo urinary bladder of human subject and comparisons with some popular algorithms are used to demonstrate its improvement in both reconstruction accuracy and efficiency.

Three‐dimensional segmentation of three‐dimensional ultrasound carotid atherosclerosis using sparse field level sets

Three-dimensional ultrasound (3DUS) vessel wall volume (VWV) provides a 3D measurement of carotid artery wall remodeling and atherosclerotic plaque and is sensitive to temporal changes of carotid plaque burden. Unfortunately, although 3DUS VWV provides many advantages compared to measurements of arterial wall thickening or plaque alone, it is still not widely used in research or clinical practice because of the inordinate amount of time required to train observers and to generate 3DUS VWV measurements. In this regard, semiautomated methods for segmentation of the carotid media-adventitia boundary (MAB) and the lumen-intima boundary (LIB) would greatly improve the time to train observers and for them to generate 3DUS VWV measurements with high reproducibility. The authors describe a 3D algorithm based on a modified sparse field level set method for segmenting the MAB and LIB of the common carotid artery (CCA) from 3DUS images. To the authors' knowledge, the proposed algorithm is the first direct 3D segmentation method, which has been validated for segmenting both the carotid MAB and the LIB from 3DUS images for the purpose of computing VWV. Initialization of the algorithm requires the observer to choose anchor points on each boundary on a set of transverse slices with a user-specified interslice distance (ISD), in which larger ISD requires fewer user interactions than smaller ISD. To address the challenges of the MAB and LIB segmentations from 3DUS images, the authors integrated regional- and boundary-based image statistics, expert initializations, and anatomically motivated boundary separation into the segmentation. The MAB is segmented by incorporating local region-based image information, image gradients, and the anchor points provided by the observer. Moreover, a local smoothness term is utilized to maintain the smooth surface of the MAB. The LIB is segmented by constraining its evolution using the already segmented surface of the MAB, in addition to the global region-based information and the anchor points. The algorithm-generated surfaces were sliced and evaluated with respect to manual segmentations on a slice-by-slice basis using 21 3DUS images. The authors used ISD of 1, 2, 3, 4, and 10 mm for algorithm initialization to generate segmentation results. The algorithm-generated accuracy and intraobserver variability results are comparable to the previous methods, but with fewer user interactions. For example, for the ISD of 3 mm, the algorithm yielded an average Dice coefficient of 94.4% ± 2.2% and 90.6% ± 5.0% for the MAB and LIB and the coefficient of variation of 6.8% for computing the VWV of the CCA, while requiring only 1.72 min (vs 8.3 min for manual segmentation) for a 3DUS image. The proposed 3D semiautomated segmentation algorithm yielded high-accuracy and high-repeatability, while reducing the expert interaction required for initializing the algorithm than the previous 2D methods.

Fetal head–symphysis distance: a simple and reliable ultrasound index of fetal head station in labor

To assess the reproducibility of measurement of a new sonographic index of fetal head station in labor, the fetal head-symphysis distance (HSD), using three-dimensional ultrasound, and its correlation with digital assessment of fetal head descent and with the angle of progression (AoP). Three-dimensional (3D) ultrasound volumes were acquired from 47 nulliparous women in active labor following assessment of fetal head station with digital examination. The HSD (the distance between the lower edge of the pubic symphysis and the nearest point of the fetal skull) was measured independently by two operators in order to evaluate intra- and interobserver reproducibility. The correlation between HSD, AoP and fetal head station was evaluated using regression analysis. Using 3D tomographic ultrasound imaging (TUI), measurements of the HSD were obtained in different parasagittal planes to evaluate the influence of inaccurate alignment of the probe with the midline of the pelvis. Measurement of HSD showed high intraobserver (intraclass correlation coefficient (ICC) = 0.995; 95% CI, 0.991-0.997) and interobserver (ICC = 0.991; 95% CI, 0.984-0.995) reliability. In addition, a high correlation was demonstrated between mid-sagittal and parasagittal HSD measurements. HSD showed significant negative correlation with both fetal head station and AoP. Fetal HSD is a simple and reliable method for the assessment of fetal head descent in labor.

Intra‐ and interobserver agreement when describing adnexal masses using the International Ovarian Tumor Analysis terms and definitions: a study on three‐dimensional ultrasound volumes

To estimate intraobserver repeatability and interobserver agreement in: (1) describing adnexal masses using the International Ovarian Tumor Analysis (IOTA) terms and definitions; (2) the risk of malignancy calculated using IOTA logistic regression model 1 (LR1) and model 2 (LR2); and (3) the diagnosis made on the basis of subjective assessment of ultrasound images. One-hundred and three adnexal masses were examined by transvaginal gray-scale and power Doppler ultrasound. Three-dimensional ultrasound volumes of the mass were saved. After 12-18 months the volumes were analyzed twice, 1-6 months apart, by each of two independent experienced sonologists who used the IOTA terms and definitions to describe the masses. The risk of malignancy was calculated using LR1 and LR2. The sonologists also classified the masses as benign or malignant using subjective assessment. Eighty-four masses were benign, eight were borderline and 11 were invasively malignant. There was substantial variability within and between observers in the results of measurements included in LR1 and LR2 and some variability also when assessing categorical variables included in the models (agreement = 51-100% and kappa = 0.42-1.00). This resulted in substantial variability in the calculated risk of malignancy, the limits of agreement indicating that the calculated risk of malignancy could vary by a factor of 5-20 within and between observers. The reliability of the calculated risk of malignancy was moderate (LR1) or poor (LR2) when the calculated risk of malignancy was > 10% (intraclass correlation coefficients varied from 0.21 to 0.73). Interobserver agreement when classifying tumors as benign or malignant using the predetermined risk of malignancy cut-off of 10% was fair to good (agreement = 85% and kappa = 0.61 for LR1; agreement = 81% and kappa = 0.52 for LR2). Intra- and interobserver agreements for subjective assessment were 96%, 96% and 96% with kappa values of 0.89, 0.87 and 0.88, respectively. Intra- and interobserver agreement in classifying tumors as benign or malignant using the risk of malignancy cut-off of 10% for LR1 and LR2 was fair or good, whilst the reproducibility of subjective assessment was excellent. The reliability of calculated risks > 10% was poor, and calculated risk > 10% cannot be used to discriminate between individuals at different risk. These results cannot be extrapolated to real-time ultrasound examinations.

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

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. 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. 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. 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.

Fetal volume measurements with three dimensional ultrasound in the first trimester of pregnancy, related to pregnancy outcome, a prospective cohort study

BackgroundFirst trimester growth restriction is associated with an increased risk of adverse birth outcomes (preterm birth, low birth weight and small for gestational age at birth). The differences between normal and abnormal growth in early pregnancy are small if the fetal size is measured by the crown-rump-length. Three-dimensional ultrasound volume measurements might give more information about fetal development than two-dimensional ultrasound measurements. Detection of the fetus with a small fetal volume might result in earlier detection of high risk pregnancies and a better selection of high risk pregnancies.MethodsA prospective cohort study, performed at the Máxima Medical Centre, in Eindhoven-Veldhoven, the Netherlands. During the routine first trimester scan with nuchal translucency measurement 500 fetal volumes will be obtained. The gestational age is based on the first day of the last menstrual period in a regular menstrual cycle and by the crown-rump-length. The acquired datasets are collected and stored on a hard disk for offline processing and volume calculation. The investigator who performs the volume measurements is blinded for the results of the first trimester scan. The manual mode will be used to outline the Region Of Interest, the fetal head and rump, in all cross sections. The fetal volumes are calculated with a rotational step of 9°.First, the relation between fetal volume and gestational age, for a set of participants with normal pregnancies (training set), will be assessed. This model will then be used to determine expected values of fetal volume for a normal pregnancy, which will be referred to as expected normal values. Secondly, for a new set of participants with normal pregnancies and a set of participants with complicated pregnancies (together defined as validation set), the observed fetal volumes (FVobserved) are compared with their expected normal values (FVexpected) and expressed as a percentage of the expected normal value. The mean difference in percentage error between the set of normal versus complicated pregnancies will then be compared using the independent-samples t-test. Finally, logistic regression analysis will be applied to the validation set of participants to analyze the possibility of predicting the pregnancy outcome after fetal volume calculation in the first trimester, using this percentage error.DiscussionAfter this study it is clear whether FV measurement in the first trimester can detect high risk pregnancies. If it is possible to detect these pregnancies, more intensive follow up in these pregnancies might result in fewer complicated pregnancies and fewer fetal morbidities.

A new semi‐automated method for fetal volume measurements with three‐dimensional ultrasound: preliminary results

Complications in pregnancy are suggested to be the result of intrauterine conditions in the first trimester of pregnancy. Three-dimensional ultrasound volume measurements might give more information, compared with two-dimensional measurements. Commonly available methods for volume measurements are not suited for daily practice. This is a report of preliminary results of a promising, more practical semi-automated method for volume calculations with three-dimensional ultrasound. Volume datasets of 16 objects (10.2-41.5 cm(3) ) were obtained. Euclidean shortening flow and Perona and Malik were used as image enhancement techniques. The image gradient was calculated. The points of interest were detected by the iso-intensity and the edge-detection technique. Volume measurements with Volume Computer-aided AnaLysis (VOCAL) are used as a reference. A volume dataset of a first trimester fetus was acquired to test this method in vivo. The mathematical calculations with iso-intensity (Perona and Malik: average= -1.57 cm(3) , SD=4.05; and Euclidean shortening flow: average= -1.38 cm(3) , SD=2.47) showed results comparable with the VOCAL method (average= +1.28 cm(3) , SD=2.07). We also succeeded in detecting all voxels in the whole contour of a 12-week fetus. Mathematical volume calculations are possible with the semi-automated method. We were able to apply this new method on a first trimester fetus. This new method is promising for future use in the daily practice.

The Relationship of Carotid Three-Dimensional Ultrasound Vessel Wall Volume with Age and Sex: Comparison to Carotid Intima-Media Thickness

The relationship of three-dimensional ultrasound (3DUS)-derived carotid vessel wall volume (VWV) was evaluated with respect to age and sex. B-mode and 3DUS images were acquired for 316 subjects from diverse groups including obese primary prevention, diabetic nephropathy, renal transplant and rheumatoid arthritis populations. The relationship for intima-media thickness (IMT) and VWV with age and sex were determined using Pearson-product-moment correlations. Mean IMT (r = 0.18, p = 0.001) and VWV (r = 0.24, p < 0.01) correlated modestly with age. There were modest correlations in males (IMT, r = 0.19, p = 0.003; VWV, r = 0.34, p < 0.001) and in females for IMT and age (r = 0.30, p = 0.007) but not between 3DUS VWV and age in females (r = 0.10, p = 0.4). Significant associations between plaque and VWV (r = 0.36, p = 0.001) but not IMT suggest different correlations in females that may be attributed to plaque.

3D ultrasound DICOM data of the thyroid gland

SummaryPurpose: It has recently become possible to generate and archive three-dimensional ultrasound (3D-US) volume data with the DICOM standard Enhanced Ultrasound Volume Storage (EUVS). The objective of this study was to examine the application of the EUVS standard based on the example of thyroid ultrasound. Patients, methods: 32 patients, who were referred for thyroid diagnosis, were given a 3D-US examination of the thyroid gland (GE Voluson E8, convex 3D probe RAB4–8-D). The 3D data sets were exported to EUVS. Necessary additions to DICOM entries and transformation into an established DICOM standard were carried out. The visual assessment and volume measurements were performed by two experts on nuclear medicine using standard software in our hospital. Results: In 24/32 (75%) of the patients, the whole organ was successfully recorded in a single 3D scan; in 8/32 (25%), only part of organ could be covered. In all cases, 3D-US data could be exported and archived. After supplementing the DICOM entry Patient Orientation and transformation into the DICOM PET format, 3D-US data could be displayed in the correct orientation and size at any viewing workstation and any web browser-based PACS viewer. Afterwards, 3D processing such as multiplanar reformation, volumetric measurements and image fusion with data of other cross sectional modalities could be performed. The intraclass correlation of the volume measurements was 0,94 and the interobserver variability was 5.7%. Conclusion: EUVS allows the generation, distribution and archiving of 3D-US data of the thyroid, facilitates a second reading by another physician and creates conditions for advanced 3D processing using routine software

Real-time image-based rigid registration of three-dimensional ultrasound

Registration of three-dimensional ultrasound (3DUS) volumes is necessary in several applications, such as when stitching volumes to expand the field of view or when stabilizing a temporal sequence of volumes to cancel out motion of the probe or anatomy. Current systems that register 3DUS volumes either use external tracking systems (electromagnetic or optical), which add expense and impose limitations on acquisitions, or are image-based methods that operate offline and are incapable of providing immediate feedback to clinicians. This paper presents a real-time image-based algorithm for rigid registration of 3DUS volumes designed for acquisitions in which small probe displacements occur between frames. Described is a method for feature detection and descriptor formation that takes into account the characteristics of 3DUS imaging. Volumes are registered by determining a correspondence between these features. A global set of features is maintained and integrated into the registration, which limits the accumulation of registration error. The system operates in real-time (i.e. volumes are registered as fast or faster than they are acquired) by using an accelerated framework on a graphics processing unit. The algorithm's parameter selection and performance is analyzed and validated in studies which use both water tank and clinical images. The resulting registration accuracy is comparable to similar feature-based registration methods, but in contrast to these methods, can register 3DUS volumes in real-time.

Three-dimensional ultrasound imaging of the urogenital hiatus in pelvic organ prolapse women

Objective To provide an effective imaging technique for the morphological observation of the urogenital hiatus in pelvic organ prolapse women using three-dimensional ultrasound. Methods In a prospective observational study, forty patients with pelvic organ prolapse and thirty nulliparous women underwent three-dimensional transperineal ultrasound, with the patients supine after bladder emptying. The three-dimensional ultrasound volume was acquired and the form, structure, composition and size of urogeital hiatus were observed in the axial plane set by interior-inferior edge of symphsis pubis and analrectum junction. Results The urogenital hiatus in pelvic organ prolapse women was obviously different from the control's. The size increased sharply, the morphology represented as oval replacing the normal rotundity, the middle line diverged from the normal position, organs inside the hiatus arranged abnormally and the connective tissue defected. Conclusions Three-dimensional ultrasound is an effective imaging method to observe female pelvic floor. Urogenital hiatus in pelvic organ prolapse women displayed abnormities with morphology and structure. Key words: Ultrasonography, three-dimensional ; Pelvic floor ; Urogenital hiatus ; Prolapse