Three-dimensional Power Doppler Ultrasonography Research Articles

Ultrasound of the Placenta: A Systematic Approach. Part II: Functional Assessment (Doppler)

Doppler velocimetry is the ideal clinical tool to assess placental performance in high-risk pregnancies. It also has value in predicting later complications and outcome in pregnancies which appear uncomplicated. All three circulations (fetal, placental and maternal) may be interrogated by Doppler technology. In the following review, we present basic physics aspects of Doppler and discuss mainly Doppler investigation of the fetal–placental circulation (umbilical artery, intraplacental circulation) as well as the uterine arteries. The assessment of umbilical blood flow provides information on blood perfusion of the fetal–placental unit. The diastolic blood flow velocity component in umbilical artery increases with advancing gestation. In pregnancies complicated by placental dysfunction, there may be a reduction in the number of functional villi and/or small blood vessels with, as a result, increased impedance, reflected, mainly, by a decrease in end-diastolic velocity. When the resistance increases even more, there is no diastolic forward velocity (absent end-diastolic velocity). Further increase in the resistance causes reversed end-diastolic velocity, which is considered a late step in the cascade of events leading to intrauterine fetal demise. Doppler assessment of the umbilical arteries was found to improve outcome of high-risk pregnancies, and reduce hospital admissions. On the contrary, routine Doppler ultrasound in low risk or unselected populations does not seem to confer benefit on mother or newborn. Uterine artery Doppler is a useful test in predicting pregnancies at high risk of developing complications related to uteroplacental insufficiency. It identifies women who may benefit from increased antenatal surveillance or prophylactic therapy. Three-dimensional power Doppler sonography can provide new insights into placental pathophysiology.

Evaluation of volume vascularization index and flow index: a phantom study

Three-dimensional (3D) power Doppler ultrasonography provides indices to quantify moving blood within a volume of interest (e.g. ovary, endometrium, tumor or placenta). The purpose of this study was to determine the influence of ultrasound instrument settings on vascularization index (VI) and flow index (FI) at different flow velocities, using a specially built flow phantom with a small tube diameter. Blood-mimicking fluid was pumped at 10-100 mL/h through a plastic tube with a diameter of 0.65 mm within a virtual spherical volume (content 137.12 cm(3)) of a Voluson 730 Expert 3D power Doppler ultrasound instrument. VI and FI were determined at different pulse repetition frequency (PRF) settings, with minimal and maximal wall motion filter (WMF) settings. The measured VI was compared with the actual VI. The ability to measure VI and FI at different flow velocities was highly dependent on the PRF and WMF settings. In our experimental set-up, using a PRF of 0.3 kHz, flow velocities of about 2 cm/s and higher could be registered. Measured VI was overestimated up to 44 times relative to actual VI. Our main finding in a laboratory set-up was a considerable overestimation of moving blood volume using 3D power Doppler ultrasound in a single small tube. The degree of overestimation depends on the spatial resolution and on the settings of the ultrasound instrument. When small vessels are involved in a clinical setting, interpretation of VI should take this overestimation of moving blood volume into account.

OP18.02: Effect of rising hCG levels on the human corpus luteum during early pregnancy

BACKGROUND: During early pregnancy, the most important task of the corpus luteum (CL) is to produce sufficientprogesterone until the luteoplacental shift occurs. Progesterone production is closely related to the extensive vascula-ture surrounding and supplying the CL. The synthesis of both progesterone and factors controlling the vasculature inthe CL is regulated by hCG, which is released initially at rising levels from the placenta. The primary aim of thisresearch was to evaluate changes in the CL vasculature during early pregnancy. METHODS: Twenty naturally con-ceived pregnancies were examined weekly from weeks 5 to 11. At each visit, blood samples were obtained to determinethe concentrations of hCG, progesterone and 17-OH progesterone (17-OHP). The vasculature in the ovaries wasassessed using three-dimensional power Doppler ultrasonography. RESULTS: The vascular supply in the ovary con-taining the CL was greatest at week 5, and thereafter, declined continuously until week 11. The decrease in the vas-culature correlated with the decrease in 17-OHP. Mean hCG levels reached a maximum at week 8, progesterone levelsreached the nadir at week 7 and increased after that. CONCLUSIONS: Vasculature in the CL appears to be createdalready by the fifth week of pregnancy and it does not enlarge despite rising hCG levels. The activity of the CL duringpregnancy may be measured non-invasively by assessing its vasculature with three-dimensional ultrasonography.

Three-dimensional Power Doppler Ultrasonography for Discriminating Benign from Malignant Ovarian Tumors: Current Experience

Abstract The differential diagnosis of adnexal masses still constitutes a major clinical challenge. B-mode ultrasonography is the most used imaging technique and it is the base for this differential diagnosis with acceptable results in terms of sensitivity but a relatively high false positive rate for predicting ovarian cancer. The role of pulsed Doppler remains controversial and seems to be not reproducible in clinical practice. In the last years, a new technology such as 3D ultrasound—both morphology and 3D Angio power Doppler—has become available for discriminating between benign and malignant ovarian tumors. In this article I aim to review critically recent literature of this topic.

The Assessment of Unilateral Uterine Artery Ligation in Radical Abdominal Trachelectomy with Three-Dimensional Power Doppler Ultrasonography

The conservation of uterine arteries during radical trachelectomy has led to considerable debate among gynecologic oncologists. Some authors have reported successful case studies of the ligation of bilateral uterine arteries, but other authors remain unconvinced of the artery ligation procedure. We report a case that employed three-dimensional power Doppler ultrasonography (3D-PDUS) to assess the microvascular pattern of uterine blood circulation after the ligation of a unilateral uterine artery during radical abdominal trachelectomy. The assessment of the uterine vascular circulation via the 3D-PDUS revealed no significant differences in the vascular blood supply of bilateral uterine arteries 4 months postoperatively. [International Journal of Gerontology 2008; 2(1): 22–25]

Reliability, repeatability and reproducibility: analysis of measurement errors in continuous variables

Reliability, repeatability and reproducibility: analysis of measurement errors in continuous variables

Assessment of ovarian vascularization in the polycystic ovary by three-dimensional power Doppler ultrasonography

Objective. To assess whether there are differences in ovarian echogenicity and vascularization as assessed by three-dimensional power Doppler angiography (3D-PDA) between women with polycystic ovaries (PCO) and women with normal ovaries (NO).Methods. Eighty-three women were classified into two groups according to the 2003 Rotterdam consensus criteria. The NO group comprised women (n = 45) with regular menstrual cycles and proven fertility, whereas the PCO group comprised women (n = 38) with oligo-anovulation, clinical and/or biochemical features of hyperandrogenism, and polycystic ovary morphology at two-dimensional ultrasound. All women were evaluated by means of 3D-PDA. The parameters studied in both groups were follicle number per ovary (FNPO), ovarian volume (OV), mean gray value (MG) and three vascular indices: vascularization index (VI), flow index (FI) and vascularization flow index (VFI).Results. The PCO group showed a higher mean OV as well as FNPO. No differences in MG, VI, FI and VFI were found between the groups.Conclusions. 3D-PDA indices are not useful for discriminating between normal and polycystic ovaries.

Three-dimensional power Doppler sonography of the (sub)endometrium and angiogenic cytokine concentrations

The aim of this study was to determine the correlation between three-dimensional power Doppler sonography (3D-PDS) of the (sub)endometrium and concentrations of angiogenic cytokines in patients attending an IVF programme. A total of 42 patients was included in a prospective, non-randomized clinical study. 3D-PDS of the (sub)endometrium was performed on the day of oocyte aspiration, with and without contrast agent. Quantitative assessment included the following 3D Doppler parameters: vascularization index, flow intensity, and vascularization flow index. On the same day, concentrations of oestradiol (serum only), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF) 1, IGF-binding protein 3 (IGFBP-3) and leptin were determined in the serum and in the follicular fluid. All 3D-PDS indices were significantly higher with contrast enhancement ( P < 0.05). Follicular fluid concentrations of VEGF and IGFBP-3, as well as serum concentrations of leptin, showed significant P-values when correlated with (sub)endometrial Doppler indices. A weak linear dependency appeared between flow intensity and VEGF and leptin. Furthermore, weak dependencies were apparent between 3D Doppler parameters and high follicular fluid concentrations of VEGF and IGFBP-3. It is concluded that there is only little evidence for an association between (sub)endometrial Doppler indices as assessed by 3D-PDS and concentrations of angiogenic cytokines.

311: Assessment of Changes in Uterine Volume and Vascularity Following Laparoscopic Myomectomy and Ligation of the Uterine Arteries Using Three-Dimensional Power Doppler Ultrasound

311: Assessment of Changes in Uterine Volume and Vascularity Following Laparoscopic Myomectomy and Ligation of the Uterine Arteries Using Three-Dimensional Power Doppler Ultrasound

P31.19: Are there any changes in placental vascularity assessed by three‐dimensional power Doppler ultrasonography in fetal aneuploidies?

P31.19: Are there any changes in placental vascularity assessed by three‐dimensional power Doppler ultrasonography in fetal aneuploidies?

OC162: Assessment of brain vascularization and blood flow in human fetus using quantitative three‐dimensional power Doppler sonography

Objectives: New three-dimensional (3D) ultrasound technologies allow the assessment of the overall vascularization within a given volume of tissue. We applied 3D ultrasound to the study of fetal brain with two aims: to evaluate the brain perfusion in normal fetuses, and to detect the presence of eventual vascular dominance in fetal brain by comparing left to right hemisphere vascularization. Methods: We studied 65 normal fetuses of gestational age ranging from 21 to 40 weeks using 3D real-time ultrasound equipment that supports volume contrast imaging technology (Voluson 730 Expert, General Electric). The vascularization index (VI), the flow index (FI) and the vascularization–flow index (VFI) are calculated by a built-in software. These indices were derived from spherical volumes acquired in specifical anatomical regions, obtained from a transverse section of the fetal head at the level of the thalami and cavum septi pellucidi. We calculated the regression of VI, FI and VFI values of the overall vascularization, and the median VI, FI and VFI values of the right and left hemispheres. Results: VI, FI and VFI values of overall brain perfusion showed a slight, but not significant increase from 21 to 40 weeks of gestational age. Median VI (left vs. right, 2.20 (range, 0.02–14.32) vs. 1.04 (range, 0.01–12.71), P = 0.014), median FI (left vs. right, 21.68 (range, 18.18–41.36) vs. 18.25 (range, 16.43–39.40), P = 0.030) and median VFI (left vs. right, 0.66 (range, 0.06–5.38) vs. 0.33 (range, 0.04–4.32), P = 0.023) obtained by sampling the left hemispheres were significantly higher than the values obtained by sampling the right hemispheres. Conclusions: We suggest that quantitative three-dimensional power Doppler sonography can be used to study the in-utero development of the fetal brain vascular network. Moreover, we could demonstrate the presence of a vascular dominance of the left hemisphere in the fetal brain.

Placenta: angiogenesis and vascular assessment through three-dimensional power Doppler ultrasonography

The placenta is fundamental for fetal development. It combines the functions of an endocrine organ, kidneys, lungs and intestines, purifying catabolites, oxygenating and nourishing the conceptus. Its fetal portion is the largest part develops from the chorionic sac. The maternal portion, which is smaller, is originated in the endometrium, more specifically in the decidua basalis. The placenta starts its function closer to the fourth week of gestation, when anatomical arrangements for the physiological exchanges are already established. The circulatory function of the placenta appears at an early stage of embryo-placental development and it is strongly related to fetal growth, to the placental size and to uterine and umbilical blood flows. Therefore, an adequate placental angiogenesis is critical for the establishment of a normal placental vascularization with consequent normal development of the fetus. In this review article, the authors discuss about placental ontogeny, focusing on the main aspects of its normal development, and about the recent advances in ultrasonography for the study of the vascular architecture of the placenta through three-dimensional power Doppler ultrasonography.

Three-dimensional power Doppler sonography in short-term therapy monitoring of rheumatoid synovitis

Three-dimensional power Doppler sonography in short-term therapy monitoring of rheumatoid synovitis

Three-Dimensional Power Doppler Sonography in the Prenatal Diagnosis of a True Knot of the Umbilical Cord

The purpose of this study was to examine the value of 3-dimensional power Doppler sonography in the prenatal diagnosis of a true knot of the umbilical cord. Cases in which the diagnosis of a true knot of the umbilical cord was suspected by prenatal 2-dimensional sonography were reviewed. The presumably affected segment of the cord was examined with 3-dimensional power Doppler sonography for further characterization. Confirmation of the prenatal diagnosis was sought by reviewing the delivery records and contacting the referring obstetrician and the patients themselves. Eight consecutive cases were studied. Three-dimensional power Doppler sonography displayed a vascular spatial configuration pattern consistent with a true knot of the umbilical cord in all of them. However, the prenatal diagnosis was confirmed at delivery in only 5 cases (62.5%). Although there were no cases of a false knot mimicking a true knot of the umbilical cord, all incorrect diagnoses in this series were associated with multiple loops of the umbilical cord in the third trimester. Three-dimensional power Doppler sonography seems to be helpful in determining the presence of a true knot of the umbilical cord in utero, especially in the second trimester. However, this should not be considered a definitive method for the diagnosis because multiple loops of the umbilical cord lying close to each other can generate a sonographic image that can be undistinguishable from a true knot of the umbilical cord prenatally, especially when located in a small pocket of amniotic fluid. Therefore, the presumable diagnosis of a true knot of the umbilical cord in utero should be taken with caution.

Intra-Tumor Flow Index Can Predict the Malignant Potential of Breast Tumor: Dependent on Age and Volume

The aim of this study was to assess tumor vascularity through three dimensional (3D) power Doppler breast ultrasound (US) and propose a decision model for the classification of benign and malignant breast tumors. Patient recruitment for this study was performed consecutively during a 13-mo period (January 2003 to February 2004). A total of 102 benign and 93 malignant solid breast images were analyzed. Three-dimensional power Doppler US imaging was performed using a Voluson730 ultrasound system equipped with a relative stopping power index (RSP) 6 to 12 transducer. The Virtual Organ Computer-aided Analysis (VOCAL)-imaging program (version 2.1) was used to analyze the stored volume. Histogram indices of the vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) for the intra-tumor and for shells with a thickness of 3 mm surrounding the breast lesion were calculated and showed that for both, malignancy had a higher VI, FI and VFI than benignancy, with statistical significance. Multivariate and stepwise logistic regression revealed the model (including patient age, volume and intra-tumor FI in 3D power Doppler vascularity) to be the best choice for malignant breast tumor characterization. The receiver operating characteristics (ROC) index for the performance of the model was 0.926. Histogram indices for the intra-tumor FI in the 3D power Doppler scan are a good choice of parameter for differentiating between malignant and benign tumors with respect to the power of sensitivity, no matter whether one index is suggested or the patients’ age and volume are considered. (E-mail: darren_chen@cch.org.tw)

Does Three-Dimensional Power Doppler Ultrasound Help in Discrimination Between Benign and Malignant Ovarian Masses?

Gray-scale ultrasonography is a reliable and reproducible means of distinguishing between benign and malignant ovarian tumors. New blood vessel formation is a key factor in tumor growth and spread, but conventional Doppler ultrasonography has not appreciably improved the assessment of tumor vascularization. The advent of three-dimensional (3D) power Doppler ultrasound raises the possibility of objectively studying vascularization in a whole organ or tumor. The value of this modality was studied in 106 women scheduled to have surgery for an ovarian mass, which was assessed by transvaginal gray-scale ultrasound as well as two-dimensional (2D) and 3D power Doppler ultrasound. The examiner rated the color content of the tumor scan using a visual analog scale. The whole tumor and a sample taken from the most vascular area of the tumor were analyzed to determine the vascularization index (VI), flow index (FI), and vascularization flow index. An attempt was made to include the entire tumor in the 3D power Doppler studies. The series included 79 women with benign tumors, 6 with borderline lesions, and 21 with invasive tumors. A logistic regression model incorporating only gray-scale variables (size of the largest solid component, wall irregularity, lesion size) had an area under the receiver-operating characteristics (ROC) curve of 0.98, was 100% sensitive, had a false-positive rate of 10%, and had a positive likelihood ratio of 10 when using the mathematically best cutoff value for risk of malignancy. The 3D FI in the most vascular part of the tumor—the 3D parameter that performed best diagnostically—was superior to the color content of the tumor scan, with an area under the ROC curve of 0.92, sensitivity of 93%, and a false-positive rate of 16% using the mathematically best cutoff value. Adding the color content of the tumor scan or FI in the vascular tumor sample to the logistic regression model improved its diagnostic performance only marginally. There were no systematic differences between the first and second measurements of one observer or between measurements made by two observers. An experienced ultrasound examiner is able to correctly classify most adnexal tumors as benign or malignant using only gray-scale ultrasonography. Approximately 10% of tumors, however, are very problematic even for expert sonographers; it is for these cases that newer diagnostic methods, possibly including 3D power Doppler ultrasound, may prove to be helpful.

The Vascularisation of Oral Cavity Tumours and Tumour Shell Tissue Determined by Three-Dimensional Power Doppler Sonography

The aim of the study was to determine and quantify the vascularity of oral cavity tumours and peritumoural tissue by using 3-D power Doppler sonography (3-D PDS) and to compare the vascularity of metastatic and nonmetastatic tumours. The investigation was carried out preoperatively on 49 patients with squamous carcinoma of the tongue and floor of the mouth. Collected data were analysed with the help of virtual program of computer-aided analysis (VOCAL)-imaging program by which the borders of a structure could be defined and vascularity quantified by analysing 3D colour histograms. Vascularity was defined by three indices, VI- vascularisation index, FI- flow index and VFI- vascularisation-flow index. The vascularity of oral cavity tumours was determined in 4 mm and 7 mm shells surrounding the tumour. Modified neck dissection was performed in all of the patients and lymph nodes were examined histologically. Peritumorous tissue vascularity was significantly higher in metastatic ( N+ neck) than it was in nonmetastatic (N0 neck) tumours. Indices VI and VFI in 4 mm and 7 mm shells differed significantly between N+ and N0 tumours ( p < 0.01). Flow index (FI) did not show any difference between N0 and N+ necks. The difference between vascularity indices VI and VFI of peritumorous tissue and tumour was also varied significantly between N0 and N+ neck ( p < 0.05) and was higher in N+ tumours. With VOCAL software and 3-D power Doppler sonography, the vascularity of peritumorous tissue could be quantified successfully. Tumours which had metastasised showed richer vascularity in their shells and a greater difference in vascularity between the shell and tumour tissue. (E-mail: janez.rebol@guest.arnes.si)

Functional Neoangiogenesis Imaging of Genetically Engineered Mouse Prostate Cancer Using Three-Dimensional Power Doppler Ultrasound

We report the first application of high-frequency three-dimensional power Doppler ultrasound imaging in a genetically engineered mouse (GEM) prostate cancer model. We show that the technology sensitively and specifically depicts functional neoangiogenic blood flow because little or no flow is measurable in normal prostate tissue or tumors smaller than 2-3 mm diameter, the neoangiogenesis "switch-on" size. Vascular structures depicted by power Doppler were verified using Microfil-enhanced micro-computed tomography (micro-CT) and by correlation with microvessel distributions measured by immunohistochemistry and enhanced vascularity visualized by confocal microscopy in two GEM models [transgenic adenocarcinoma of the mouse prostate (TRAMP) and PSP94 gene-directed transgenic mouse adenocarcinoma of the prostate (PSP-TGMAP)]. Four distinct phases of neoangiogenesis in cancer development were observed, specifically, (a) an early latent phase; (b) establishment of a peripheral capsular vascular structure as a neoangiogenesis initiation site; (c) a peak in tumor vascularity that occurs before aggressive tumor growth; and (d) rapid tumor growth accompanied by decreasing vascularity. Microsurgical interventions mimicking local delivery of antiangiogenesis drugs were done by ligating arteries upstream from feeder vessels branching to the prostate. Microsurgery produced an immediate reduction of tumor blood flow, and flow remained low from 1 h to 2 weeks or longer after treatment. Power Doppler, in conjunction with micro-CT, showed that the tumors recruit secondary blood supplies from nearby vessels, which likely accounts for the continued growth of the tumors after surgery. The microsurgical model represents an advanced angiogenic prostate cancer stage in GEM mice corresponding to clinically defined hormone-refractory prostate cancer. Three-dimensional power Doppler imaging is completely noninvasive and will facilitate basic and preclinical research on neoangiogenesis in live animal models.

Solid Breast Masses: Neural Network Analysis of Vascular Features at Three-dimensional Power Doppler US for Benign or Malignant Classification

To retrospectively evaluate the accuracy of neural network analysis of tumor vascular features at three-dimensional (3D) power Doppler ultrasonography (US) for classification of breast tumors as benign or malignant, with histologic findings as the reference standard. This study was approved by the local ethics committee; informed consent was waived. Three-dimensional power Doppler US images of 221 solid breast masses (110 benign, 111 malignant) were obtained in 221 women (mean age, 46 years; range, 25-71 years). After narrowing down vessels to skeletons with a 3D thinning algorithm, six vascular feature values--vessel-to-volume ratio, number of vascular trees, total vessel length, longest path length, number of bifurcations, and vessel diameter-were computed. A neural network was used to classify tumors by using these features. Independent-samples t test and receiver operating characteristic (ROC) curve analysis were used. Mean values of vessel-to-volume ratio, number of vascular trees, total vessel length, longest path length, number of bifurcations, and vessel diameter were 0.0089 +/- 0.0073 (standard deviation), 26.41 +/- 14.73, 23.02 cm +/- 19.53, 8.44 cm +/- 10.38, 36.31 +/- 37.06, and 0.088 cm +/- 0.021 in malignant tumors, respectively, and 0.0028 +/- 0.0021, 9.69 +/- 6.75, 5.17 cm +/- 4.78, 1.68 cm +/- 1.79, 6.05 +/- 7.55, and 0.064 cm +/- 0.028 in benign tumors, respectively (P < .001 for all six features). Area under ROC curve (A(z)) values of the six features were 0.84, 0.87, 0.87, 0.82, 0.84, and 0.75, respectively. Accuracy, sensitivity, specificity, and positive and negative predictive values were 85% (187 of 221), 83% (96 of 115), 86% (91 of 106), 86% (96 of 111), and 83% (91 of 110), respectively, with A(z) of 0.92 based on all six feature values. Three-dimensional power Doppler US images and neural network analysis of features can aid in classification of breast tumors as benign or malignant.

Ovarian response to the human chorionic gonadotrophin stimulation test in normal ovulatory women: the impact of regressing corpus luteum

To evaluate the impact of the regressing corpus luteum on the hormone secretion during hCG stimulation. The hCG stimulation test in the early follicular phase has been used to assess the capacity of the ovarian theca cells to secrete steroids. A prospective observational study. University hospital. The study group consisted of 11 women with confirmed ovulation in the past cycle (corpus luteum positive [CL+]) and the control group of 11 women using oral contraceptive pills (OC; no CL). An hCG test (5,000 IU IM) was performed 2 to 4 days after menstrual bleeding, and the ovarian response was measured at 0, 48, and 96 hours after injection. Changes in serum concentrations of P, 17-hydroxyprogesterone (17-OHP), androstenedione (A), T, E(2), and vascular endothelial growth factor (VEGF), and in ovarian vasculature and volume (three-dimensional power Doppler ultrasonography) were measured. Secretion of P and 17-OHP increased after hCG injection in the CL group, whereas no change was observed in women on OCs (P < or = .001). Concomitant increases were observed in volume and vasculature of the ovary with a CL (P<.05), but not in the contralateral ovary or in women on OCs. The changes in volume and vasculature correlated with levels of P and 17-OHP (P<.05). The regressing corpus luteum from the past menstrual cycle reactivates and secretes steroids in response to hCG stimulation performed during the early follicular phase, which should be taken into account when comparing hormone profiles of ovulatory and anovulatory women.