Angiographic power 3-dimensional quantitative analysis in gynecologic solid tumors: feasibility and reproducibility.

OBJECTIVE: To determine the reproducibility of a simplified method of power Doppler 3-dimensional (3D) sonographic examination. METHODS: Twenty-nine patients with solid pelvic masses underwent transvaginal 3D power Doppler evaluation. The volume of interest was obtained by drawing the margins of the largest section of the mass in the 3 orthogonal planes. The 3D vascular parameters ("relative color," "average color," and "flow measure") obtained by our method were compared with those calculated by a manufacturer-suggested model based on several parallel section planes drawn on the longitudinal frames. The intraobserver variability was quantified on 5 different 3D images acquired by the same operator at 5-minute intervals for each patient. The intraobserver variability was also assayed in 10 patients at 24-hour intervals. Ten patients were scanned by a second sonographer for interobserver variability. RESULTS: There was high agreement between the 3D parameters obtained with the 2 methods. The 3D indices were similar in repeated observations at 5-minute intervals (median coefficients of variation for relative color, average color, and flow measure, 10.9, 4.5, and 13.0, respectively) and at 24-hour intervals (intraclass correlation coefficients for relative color, average color, and flow measure, 0.920, 0.978, and 0.978) and by the second sonographer (interclass correlation coefficients for relative color, average color, and flow measure, 0.978, 0.966, and 0.997). CONCLUSIONS: The acceptable rates of intraobserver and interobserver variability make this approach potentially suitable for research protocols.     

Geometry corrections in a rotating 3-dimensional sonographic system.

OBJECTIVE: To devise a system for geometry corrections in a rotating 3-dimensional sonographic system. METHODS: A 3-dimensional sonographic imaging system based on a standard sonography machine was developed. The transducer mounted in a specially designed holder was rotated about its axis to acquire the spatial information. The most important postulate in rotating 3-dimensional systems is the assumption of parallelity between the rotation axis and the transducer axis. It allows the use of simple geometric relationships between 2-dimensional slices in a 3-dimensional reconstruction. The errors appearing in the 3-dimensional reconstruction when the axes are not parallel were investigated. RESULTS: A simple correction method based on phantom measurements is proposed. The phantom contains a plane, which is inclined to the rotation axis. The analysis of 2-dimensional plane images allows the geometric corrections. The construction of the phantom is described, and the formulas used in the calculations are presented. The method was tested in computer simulations and in patient investigations. CONCLUSIONS: A complete method of the geometric investigations and corrections useful in 3-dimensional sonographic systems based on rotational geometry is proposed. Both the computer simulations and the phantom measurements confirmed the usefulness, precision, and simplicity of the proposed method.     

Sonographic depiction of intratumoral vascularity with 2- and 3-dimensional color Doppler techniques.

OBJECTIVE: The purpose of this study was to describe patterns seen on 2- and 3-dimensional color Doppler sonographic depiction of intratumoral vessels and to correlate these patterns to histopathologic findings in an attempt to assess their clinical importance. METHODS: We conducted a retrospective analysis of 26 patients with ovarian masses and intratumoral abnormalities in whom standard 2- and 3-dimensional color Doppler sonography was performed. RESULTS: Two- and 3-dimensional color Doppler sonography depicted several patterns of vascularity within ovarian masses. These included masses with vascularity confined to the wall or loculus and those with central versus peripheral vascularity. The presence of central intratumoral vascularity had a high positive predictive value (90%) for malignancy. Conversely, the absence of intratumoral vascularity had a high negative predictive value (96%). CONCLUSIONS: Three-dimensional color Doppler sonography is helpful in depicting overall vessel density and branching patterns within an intratumoral abnormality. This technique seems to be useful in distinguishing benign from malignant ovarian masses.     

Clinical usefulness of 3-dimensional sonography and power Doppler angiography for diagnosis of endometrial carcinoma.

OBJECTIVE: The purpose of this study was to assess whether endometrial volume (EV) and 3-dimensional (3D) power Doppler indices can discriminate between hyperplasia and endometrial carcinoma and can predict extension of the endometrial carcinoma. METHODS: Eighty-four women with uterine bleeding and a histopathologic diagnosis of endometrial hyperplasia (n = 29) or carcinoma (n = 55) were preoperatively examined by transvaginal 3D sonography and power Doppler angiography. Endometrial thickness (ET), EV, the vascularization index (VI), the flow index (FI), the vascularization-flow index (VFI), and the intratumoral resistive index (RI) were measured. A histopathologic diagnosis was made after endometrial biopsy was performed by hysteroscopy or curettage. RESULTS: The EV and 3D power Doppler indices (VI, FI, and VFI) were significantly higher in endometrial carcinoma than endometrial hyperplasia, whereas the intratumoral RI was significantly lower (P < .05). A VFI of 2.07 was the best cutoff for predicting endometrial carcinoma, with sensitivity of 76.5% and specificity of 80.8%. No significant differences were noticed for ET. The endometrial VI was significantly higher when the tumor stage was greater than I. All the 3D power Doppler indices were significantly higher when the carcinoma infiltrated more than 50% of the myometrium. The intratumoral RI was significantly lower in cases with a high histologic grade, myometrial infiltration of more than 50%, and lymph node metastases. CONCLUSIONS: The VI, 3D power Doppler indices, and the intratumoral RI are more useful than ET for differentiating between hyperplasia and endometrial carcinoma. Intratumoral blood flow evaluated by pulsed Doppler sonography and 3D power Doppler angiography can predict the spread of endometrial carcinoma.     

Reproducibility of fetal lung volume measurements with 3-dimensional ultrasonography.

OBJECTIVE: To build a nomogram of normal fetal lung volumes and to assess the reproducibility of measurements using 3-dimensional ultrasonography. METHODS: Inclusion criteria were healthy women, singleton normal pregnancies, reliable dating, and 20 to 30 weeks' gestation. Exclusion criteria were discordance between clinical and ultrasonographic dating, patients lost to follow-up, and birth weight disorders. Patients were scanned at intervals longer than 2 weeks. Three volumes were acquired for each patient; only data from the volume with the best image quality was used for analysis. Volumes were rated and measured by the manual tracing method. We recorded whether the clavicle was visualized. Only good-quality volumes were included in analysis. The best volume was chosen, and each lung was measured. RESULTS: A total of 75 patients were studied over a 9-month period, from which 182 volumes were analyzed. Of the 182 volumes, 15 (8.2%) were excluded for poor quality. The remaining 167 volumes were included in the final analysis. In 83 volumes (50%), the clavicle was not visualized. The best fit for total lung volume was a second-degree polynomial regression curve. Lung volume was 10.28 mL at 20 weeks and 51.49 mL at 30 weeks. Assessment of agreement was studied by selection of 40 volumes. Intraobserver variability was 5.48 mL (10.6%) and 3.07 mL (5.96%). Interobserver variability was 7 mL. CONCLUSIONS: Our findings suggest that 3-dimensional ultrasonographically derived measurements are reliable and reproducible up to 30 weeks if a standard measurement technique is used.     

The clinical value of 3-dimensional saline infusion sonography in addition to 2-dimensional saline infusion sonography in women with abnormal uterine bleeding: work in progress.

OBJECTIVE: To evaluate the clinical relevance of 3-dimensional saline infusion sonography (3D-SIS) in addition to conventional SIS in women with abnormal uterine bleeding suspected of having intrauterine abnormalities. METHODS: All women suspected of having intrauterine abnormalities were eligible. Before 3D-SIS, conventional SIS was performed. The results of these techniques were compared with the "combined method reference standard" (hysteroscopy, endometrial sampling, and clinical follow-up in cases with normal SIS findings). Diagnostic characteristics (with 95% confidence intervals [CIs]) of 3D-SIS and SIS were calculated as well as their respective accuracy in evaluating the histologic nature, the intrauterine extension, and the location of intrauterine abnormalities. Moreover, the reliability (kappa value) and clinical relevance of 3D-SIS were assessed. RESULTS: A total of 49 women were included, and 4 women were excluded. The positive predictive values of 3D-SIS and SIS were, respectively, 1.00 and 0.86 (95% CI, 0.72-0.99; P = .15), and the diagnostic accuracy values were 0.98 (95% CI, 0.94-1.0) and 0.91 (95% CI, 0.83-0.99; P = .08). Saline infusion sonography and 3D-SIS were equally accurate in evaluating the histologic nature, intrauterine extent, and location of intrauterine abnormalities (respective kappa values: 0.85 versus 0.93; P = .88; 0.83 versus 0.83; and 0.77 versus 0.80; P = .81). The reliability of 3D-SIS was good: intraobserver and interobserver agreement (kappa) were 0.78 and 0.72. Three women (6.7%) had the benefit of additional 3D-SIS: in these women, SIS wrongly led to a diagnosis of intrauterine abnormalities (P = .08). CONCLUSIONS: Three-dimensional saline infusion sonography is valid and reliable in women suspected of having intrauterine abnormalities and may indeed have relevant clinical value in addition to conventional SIS.     

Value of 3-dimensional transrectal/transvaginal sonography in diagnosis of distal ureteral calculi.

OBJECTIVE: In a prospective study, the feasibility of 3-dimensional (3D) transrectal/transvaginal sonography in comparison with transabdominal sonography and intravenous urography (IVU) in identifying distal ureteral calculi was evaluated. METHODS: Sixty-two patients in the urologic clinic with clinical suspicion of distal ureteral calculi were included. The patients consisted of 44 men and 18 women with a mean age +/- SD of 44 +/- 17 years. These patients underwent 3D transrectal/transvaginal sonography, transabdominal sonography with IVU, and, finally, ureterorenoscopy. RESULTS: Fifty-nine patients were confirmed to have distal ureteral calculi on the basis of urologic intervention (ureterorenoscopy). Three patients had a spontaneous stone passage immediately after imaging completion. The median size of the calculi was 3.7 +/- 2.00 mm. Transabdominal sonography detected 34 of the 62 patients with calculi (sensitivity, 55%). The median size of the calculi was calculated as 5.0 +/- 2.4 mm. The examination time was 6.5 +/- 2.7 minutes. Intravenous urography detected 44 of the 62 patients with ureterolithiasis (sensitivity, 71%). Herein, the median stone size was measured as 3.9 +/- 1.9 mm, and the examination time was 38 +/- 17 minutes. The combination of transabdominal sonography and IVU in visualization of ureterolithiasis raised the sensitivity to 81% (50 of 62 patients). Three-dimensional transrectal/transvaginal sonography showed ureterolithiasis in all 62 patients confirmed to have distal ureteral calculi (sensitivity and specificity, 100%). The median size of the calculi was calculated as 4.4 +/- 2.2 mm, and the examination took 1.9 +/- 0.6 minutes. CONCLUSIONS: The data in our prospective study show that transrectal/transvaginal sonography with 3D image assessment is superior to IVU and abdominal sonography for diagnosing distal ureteral calculi.     

Congenital dacryocystocele: prenatal 2- and 3-dimensional sonographic findings.

OBJECTIVE: The purpose of this series is to present our experience with cases of dacryocystocele diagnosed prenatally. The role of prenatal 3-dimensional sonography, as an adjunct to 2-dimensional sonography, in the prenatal assessment of these cases is emphasized. METHODS: A retrospective review of cases was conducted. Information was obtained by reviewing the sonographic reports and medical records. Outcomes were obtained from the referring obstetricians or directly from the parents. RESULTS: Ten fetuses had the diagnosis of a congenital dacryocystocele at a median gestational age of 30.1 weeks (range, 27-33 weeks). In 6 cases, the cystic lesion was unilateral, and in 4 it was bilateral, with a mean largest diameter at the time of diagnosis of 7.5 mm (range, 4-11 mm). There were no other associated findings. Three-dimensional sonography, carried out in 3 cases, clearly depicted the anomaly, the degree of intranasal extension, and swelling below the medial canthal area. Spontaneous resolution was documented prenatally in 5 fetuses, and 1 additional case resolved between the last prenatal scan and the delivery. There were no reported long-term complications associated with this finding, although 1 infant required probing at 2 months of age to resolve the dacryocystocele. CONCLUSIONS: Prenatal diagnosis of dacryocystocele is straightforward. A considerable number of lesions are bilateral, and many resolve in utero spontaneously or neonatally after minimal intervention. For those not resolving by the time of the delivery, ophthalmologic or rhinologic consultation is warranted because of potential complications. Three-dimensional sonography may provide a noninvasive method for evaluating these cystic masses and may contribute to the avoidance of additional diagnostic techniques in the neonatal period.     

Validation of volume and mass assessments for human fetal heart imaging by 4-dimensional spatiotemporal image correlation echocardiography: in vitro balloon model experiments.

OBJECTIVE: This study was designed to validate a slow-sweep real-time 4-dimensional (4D) spatiotemporal image correlation method for producing quantitatively accurate dynamic fetal heart images using an in vitro pulsatile balloon model and apparatus. METHODS: To model fetal heart chambers, asymmetric double-walled finger stalls (tips of surgical latex gloves) were used and attached to a laboratory-designed circuit that allowed calibrated changes in the inner balloon volume as well as an intermediate gel mass interposed between the 2 layers. The water-submerged model was attached to a small-volume pulsatile pump to produce phasic changes in volume within the inner balloon at a fixed rate. A sonography system with 4D spatiotemporal image correlation (STIC) capabilities was used for 3-dimensional (3D) and 4D data acquisition. Volume data were analyzed by customized radial summation techniques with 4D data analysis software and compared with known volumes and masses. RESULTS: Fifty-six individual volumes ranging from 2.5 to 10 mL were analyzed. Volume and mass measurements with 4D STIC were highly correlated (R2 > 0.90). The mean percentage error was better (<6%) for volumes exceeding 4 mL and was as low as 0.3% for 6-mL estimations. Measurements in the diastolic phase were the most accurate, followed by mass estimations equivalent to chamber walls. There was a wider range of percentage error in the lowest volumes tested (2.5 mL), which might have arisen from difficulties in spatial resolution or distortions from within the model apparatus itself. Resolution limitations of 4D technology in combination with extremely small volume targets may explain higher error rates at these small volumes. CONCLUSIONS: Four-dimensional STIC is an acceptably accurate method for volume and mass estimations in the ranges comparable with mid- and late-gestation fetal hearts. It is particularly accurate for diastolic estimations, for chamber wall mass measurements, and at volumes of greater than 2.5 mL. This study validates use of 4D STIC technology to overcome the limitations of nongated 3D technology for phasic and quantitative assessments in fetal echocardiography.     

Improving the efficiency of gynecologic sonography with 3-dimensional volumes: a pilot study.

OBJECTIVE: The purpose of this study was to determine whether 3-dimensional (3D) sonography can provide a rapid, efficient, and accurate way to do a transvaginal gynecologic scan compared with traditional 2-dimensional (2D) sonography. METHODS: Thirty-five consecutive patients who underwent gynecologic sonography formed the study cohort. After a standard 2D transvaginal scan was done, including measurements of the endometrium and abnormalities, 4 volume acquisitions were obtained, encompassing the uterus (2 volumes) and the ovaries. These volumes were reviewed offline without any patient information. Endometrium and other measurements were performed on the volumes. The 2D and 3D results were compared by paired t tests. RESULTS: The mean time needed for the standard 2D scan was 2.6 minutes compared with 1.07 minutes for the 3D volume acquisitions. The mean time for the reconstruction, measurement, and interpretation of the volumes offline was 1.19 minutes. The mean time for the entire 3D examination (both parts) was 2.26 minutes (P = .047, comparing 2D with total 3D). There was no significant difference between the measurements of the endometrium, fibroids, and ovarian cysts when comparing 2D and reconstructed 3D images. Two-dimensional and 3D sonography differed little in their ability to identify the organs and the abnormalities on the scans. CONCLUSIONS: This study shows that a complete transvaginal gynecologic examination can be done in 1.07 minutes of scan time and interpreted offline in an additional 1.19 minutes. The 35 cases were scanned and interpreted with the use of 3D sonography in 79.17 minutes total compared with 91.46 minutes of 2D scan time (P = .047). The accuracy of the scan was similar for both techniques.     

Sonographic nomogram of the fetal calf between 15 and 42 weeks' gestation using 3-dimensional sonography.

OBJECTIVE: The purpose of this study was to establish a new reference growth chart of calf muscle biometric measurements throughout gestation in normal singleton pregnancies. METHODS: A prospective cohort study was designed. One hundred pregnant women were included in the study and assessed by 3-dimensional sonography. Excluded were those with multiple pregnancies, congenital anomalies, abnormal karyotypes, and polyhydramnios or oligohydramnios. Three-dimensional multiplanar sonographic images were used to measure the calf muscles: soleus, gastrocnemius, popliteal, peroneus longus, and tibialis posterior. RESULTS: Calf muscle widths increased with increasing gestational age (R(2) = 0.857; P < .0001), and the ratio between calf muscles and the tibia increased as well (R(2) = 0.356; P = .001). CONCLUSIONS: The data provide a nomogram of calf width with a direct correlation between muscle growth and gestational age. This nomogram can offer a basis for normal calf development and may assist in distinguishing between different etiologies leading to clubfoot and other joint contractures associated with calf atrophy.     

Four-dimensional ultrasonography of the fetal heart using color Doppler spatiotemporal image correlation.

OBJECTIVE: To describe clinical and research applications of 4-dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. METHODS: Forty-four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double-inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7-34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume-rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. RESULTS: Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. CONCLUSIONS: Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.     

Spatiotemporal image correlation artifacts in an in vitro model

An experimental in vitro setting with a latex miniature balloon was designed to test the accuracy of volumetric measurements by spatiotemporal image correlation. Two-dimensional images clearly showed the round balloon as a thin echogenic ring in a translucent area. Four-dimensional reconstructed images, however, showed a severely distorted balloon. The artifacts disappeared when the surroundings of the balloons were made echogenic, mimicking the in vivo setting. We hypothesize that the artifacts were the result of gating errors. These experiments can be relevant for analysis of spatiotemporal image correlation volumes in daily practice.     

Three-dimensional quantification of tumor vascularity as a tertiary test after B-mode and power Doppler evaluation for detection of ovarian cancer.

OBJECTIVE: The purpose of this study was to investigate the role of 3-dimensional (3D) quantification of tumor vascularity in the differential diagnosis of pelvic indeterminate masses with a solid appearance or unilocular or multilocular cysts with a solid component showing central vascularization on 2-dimensional power Doppler sonography. METHODS: One hundred fifty-seven consecutive pelvic masses in 153 patients were included in this study and underwent sonography before surgery. Masses that showed a typical benign pattern on B-mode sonography (n = 112) and indeterminate masses with peripheral or absent flow on power Doppler sonography (n = 10) were not evaluated by 3D sonography. Only masses with central vascularization were submitted to 3D power Doppler imaging (n = 35). The following 3D vascular parameters were calculated: relative color and flow measure (similar to the vascularization flow index obtained with other systems). RESULTS: With receiver operating characteristic curve analysis, the best cutoff values for relative color and flow measure were 4.4 and 2.7, respectively. Flow measure had sensitivity of 68% and specificity of 40% in the overall population submitted to 3D power Doppler sonography. Accuracy slightly increased when masses with small papillary projections (<10 mL) were excluded. In this group (n = 22), sensitivity was 83%, and specificity was 50%. CONCLUSIONS: In masses with central vascularization on 2-dimensional power Doppler sonography, the use of 3D quantification of tumor vascularity had low diagnostic accuracy in the detection of adnexal malignancies, although an increase in accuracy in masses with a solid portion of greater than 10 mL was reported.     

Dynamic transurethral sonography and 3-dimensional reconstruction of the rhabdosphincter and urethra: initial experience in continent and incontinent women.

OBJECTIVE: The purpose of this study was to evaluate the female urethra and the striated urinary sphincter, the rhabdosphincter (RS), by means of dynamic transurethral sonography and sonographic 3-dimensional (3D) reconstructions. METHODS: In 15 female patients with urinary stress incontinence (mean age, 67.5 years) and 5 continent women (mean age, 48.3 years), morphologic characteristics and function of the RS and urethra were examined with a 10-MHz transurethral ultrasound transducer. With the help of a mechanical pullback system, the transducer was slowly retracted to scan the whole urethra and the RS from the bladder neck to the urethral orifice. Subsequently, 3D reconstructions of the urethra using an integrated computer system were performed. The RS as well as the length of the urethra were investigated under contracted and noncontracted conditions to measure contractility of the RS and dynamic changes of the lower urinary tract. RESULTS: Partial or complete loss of RS function was detected in patients with stress incontinence. The findings on sonography were found to correlate well with the grade of incontinence. Furthermore, under contraction of the RS, a median increase in urethral length was observed. In incontinent patients, the increase in the urethral length was statistically significantly less (P = .04), which was related to the reduced contractility of the RS. CONCLUSIONS: Dynamic transurethral sonography with subsequent 3D reconstructions allows for assessment of function and morphologic characteristics of the RS and urethra. Normal contraction of the RS results in an elongation of the urethra.     

Real-time 3-dimensional fetal echocardiography with an instantaneous volume-rendered display: early description and pictorial essay.

OBJECTIVE: Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. METHODS: We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. RESULTS: Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. CONCLUSIONS: Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.