Three‐Dimensional Vascular Indices Calculated Using Conventional Power Doppler and High‐Definition Flow Imaging

Objective. The purpose of this study was to determine whether there are differences in 3‐dimensional (3D) vascular indices when calculated using high‐definition flow imaging (HDF) and power Doppler imaging (PD). Methods. Twenty‐five consecutive asymptomatic premenopausal women (mean age, 31 years; range, 28–33 years) without a history of gynecologic disease who attended routine gynecologic checkups were included in the study. All women had regular menstrual cycles, and none had uterine or myometrial disease detected on basal transvaginal sonography. All women underwent 3D transvaginal sonography. In each patient, a first volume using conventional PD was obtained, immediately followed by a second volume using HDF. Volumes were stored and subsequently analyzed for calculating 3D vascular indices (vascularization index [VI], flow index [FI], and vascularization‐flow index [VFI]) from the endometrium. Results. The median VI, FI, and VFI were significantly higher when calculated using HDF compared with conventional PD (P < .05). Conclusions. Three‐dimensional vascular indices calculated using HDF are higher than those calculated using conventional PD.     

Comparing Image Processing Techniques for Improved 3‐Dimensional Ultrasound Imaging

Objective. The purpose of this study was to compare volumetric image processing techniques for reducing noise and speckle while retaining tissue structures in 3‐dimensional (3D) gray scale ultrasound imaging. Methods. Eighty subjects underwent a clinically indicated abdominal or obstetric 3D ultrasound examination (20 hepatic, 20 renal, and 40 obstetric cases). Volume data were processed on a pixel (“2‐dimensional [2D] processing”) or a voxel (“3D processing”) basis using commercially available image enhancement software (ContextVision AB, Linköping, Sweden). Randomized, side‐by‐side comparisons of the image processing techniques were performed for each subject. An independent and blinded reader scored the volumes for image quality on a 3‐point scale from 1 (worst) to 3 (best) and compared the results using a nonparametric Wilcoxson signed rank test. Results. The 40 subjects with abdominal 3D imaging received a mean score (± 1 SD) of 1.52 ± 0.51, 2.45 ± 0.60, and 2.75 ± 0.44 for the original, the 2D processed, and the 3D processed volumes, respectively. The differences between the unprocessed and the processed volumes were highly statistically significant (P < .0001), as was the difference between the 2D and 3D processing methods (P = .002). Similar results were obtained for the obstetric data sets (n = 39 due to an acquisition problem) with a mean score of 1.03 ± 0.16 for the original, 2.33 ± 0.48 for the 2D processed, and 2.79 ± 0.47 for the 3D processed volumes (P < .003). Conclusions. A new volumetric ultrasound image enhancement technique has been assessed in abdominal and obstetric applications. Compared to unprocessed volumes and volumes processed with 2D image enhancement software, the new 3D processing technique performed best.     

Contrast‐Enhanced Ultrasonography With SonoVue

Objective. We investigated the ability of contrast‐enhanced ultrasonography with SonoVue (Bracco SpA, Milan, Italy), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal splenic lesions. Methods. In a prospective study we investigated 35 lesions in 35 patients (24 male and 11 female; mean age ± SD, 54 ± 15 years) with focal splenic lesions detected by B‐mode ultrasonography. After intravenous injection of 1.2 to 2.4 mL of SonoVue, the spleen was examined continuously for 3 minutes using low–mechanical index ultrasonography with contrast‐specific software. The final diagnosis was established by histologic examination, computed tomography, or magnetic resonance imaging. Results. In 14 patients, the splenic lesions were malignant (metastasis, n = 6; non‐Hodgkin lymphoma, n = 6; and Hodgkin lymphoma, n = 2). In 21 patients, the focal splenic lesions were benign (ischemic lesion, n = 6; echogenic cyst, n = 5; abscess, n = 4; hemangioma, n = 3; hematoma, n = 1; hemophagocytosis syndrome, n = 1; and splenoma, n = 1. Typical findings for benign lesions were 2 arrival patterns: no contrast enhancement (neither in the early nor in the parenchymal phase; P < .05) and the beginning of contrast enhancement in the early phase followed by contrast enhancement in the parenchymal phase 60 seconds after injection. In contrast, the combination of contrast enhancement in the early phase followed by rapid wash‐out and demarcation of the lesion without contrast enhancement in the parenchymal phase (60 seconds after injection) was typical for malignant lesions (P < .001). Conclusions. Contrast‐enhanced ultrasonography is helpful in the differentiation between benign and malignant lesions of the spleen.     

Quality of 2‐ and 3‐Dimensional Fast Acquisition Fetal Cardiac Imaging at 18 to 22 Weeks

Objective. The purpose of this study was to evaluate the frequency with which 6 different fetal cardiac views taken during a fetal ultrasound examination at 18 to 22 weeks' gestation can be obtained satisfactorily for cardiac anomaly screening using either a 2‐dimensional (2D) static or 3‐dimensional (3D) fast acquisition technique. Methods. A prospective study of 100 low‐risk women undergoing an anatomic survey was performed. Standard static 2D and 3D fast acquisition volumes were obtained on all patients. The 2D and 3D images were assigned, in a random order, to be independently graded by 3 reviewers. The degree of inter‐reviewer agreement was assessed through the use of the Cohen κ statistic. The factors contributing to satisfactory imaging were evaluated by random effects logistic regression. Results. A significant proportion of both 2D and 3D images were judged unsatisfactory for screening purposes. However, 2D images were significantly more likely, for all cardiac views, to be judged satisfactory (P < .05). The odds ratios for the 2D technique's being more likely than the 3D technique to provide images satisfactory for screening were 2.6 for the 4‐chamber view, 2.4 for the right ventricular outflow tract, 4 for the left ventricular outflow tract, 3.2 for the 3‐vessel view, 8.6 for the aortic arch, and 2.2 for the ductal arch. Conclusions. In this prospective study, static 2D imaging was significantly more likely than fast acquisition 2D imaging to yield cardiac views of high enough quality to satisfactorily screen for anomalies.     

Three‐Dimensional Ultrasonography of the Fetal Vermis at 18 to 26 Weeks' Gestation

Objective. The purpose of this study was to establish the normality of the fetal vermis, ie, the time of appearance of the primary fissure, as well as its measurements between 18 and 26 weeks' gestation, using 3‐dimensional (3D) ultrasonography. Methods. A prospective cross‐sectional study of normal singleton pregnancies was conducted. Examinations were performed with high‐resolution transabdominal ultrasonography using the axial plane in 173 fetuses between 18 and 26 weeks' gestation. Postprocessing measurements of the fetal vermis were done with 4‐dimensional software using static volume contrast imaging and tomographic ultrasound imaging in the C‐plane. Detection of the primary fissure was evaluated in all cases, and the time of appearance was documented. Results. Adequate vermis measurements were obtained in 173 fetuses. Vermian length as a function of gestational age was expressed by regression equations, and the correlation coefficients were found to be highly statistically significant (P < .001). The normal mean ± 2 SD for each gestational week was defined. The primary fissure was observed at 24 weeks' gestation in all cases, at 22 weeks in 94% of cases, and as early as 18 weeks in 40%. Conclusions. This 3D study documents the appearance of the primary fissure and presents the normal range of vermian measurements, confirming normal development of the fetal vermis starting as early as 18 weeks' gestation. It also shows an easy method for visualizing the vermis with 3D ultrasonography at every gestational week regardless of fetal presentation.     

Correlation of Quantified Contrast‐Enhanced Sonography With In Vivo Tumor Response

Objective.. The purpose of our study was to establish in vivo criteria for monitoring tumor treatment response using 3‐dimensional (3D) volumetric gray scale, power Doppler, and contrast‐enhanced sonography. Methods.. Twelve mice were implanted with Lewis lung carcinoma cells on their hind limbs and categorized to 4 groups: control, chemotherapy, radiation therapy, and chemoradiation. A high‐frequency ultrasound system with a 40‐MHz probe was used to image the tumors. Follow‐up contrast‐enhanced sonography was performed on days 7 and 14 of treatment with two 50‐μL boluses of a perflutren microbubble contrast agent injected into the tail vein. The following contrast‐enhanced sonographic criteria were quantified: time to peak, peak intensity, α (microvessel cross‐sectional area), and β (microbubble velocity). Three‐dimensional power Doppler images were also obtained after the acquisition of contrast data. On day 15, the tumors were excised for immunohistochemical analysis with CD31 fluorescent staining. Results.. The tumor size and 3D power Doppler vascular index showed no statistically significant correlation with microvascular density in all examined groups. Among all of the analyzed contrast‐enhanced sonographic parameters, relative α showed the strongest correlation with the histologic microvessel density (Pearson r = 0.93; P < .01) and an independent association with the histologic data in a multiple regression model (beta = .93; R² = 0.86; P < .01). Conclusions.. Of the various examined sonographic parameters, α has the strongest correlation with histologic microvessel density and may be the parameter of choice for the noninvasive monitoring of tumor angiogenic response in vivo.     

Three‐Dimensional Power Doppler Angiography of Cyclic Ovarian Blood Flow

Objective. The purpose of this study was to assess the vascular indices generated by 3‐dimensional (3D) power Doppler angiography by evaluating the cyclic changes in the vascularity of normal ovaries, including those that were ovulating, nonovulating, and hormonally suppressed. Methods. In this prospective longitudinal observational study, a cohort of premenopausal regularly menstruating women with no known ovarian disease underwent 3D power Doppler imaging every 2 to 3 days for the duration of 1 menstrual cycle. Four indices were generated: vascularization index (VI), flow index (FI), vascularization‐flow index (VFI), and mean grayness. Comparisons of vascularity were made between ovulating, nonovulating, and hormonally suppressed ovaries. Normal ranges were established and graphed longitudinally. Results. Eighteen participants (36 ovaries) ages 28 to 45 years underwent an average of 10 examinations, yielding 368 acquired ovarian volumes for analysis. Seven participants used hormonal contraception. The VI, FI, and VFI were closely correlated (Pearson product moment correlation coefficients, 0.52–0.95). The vascular indices of ovulating ovaries were significantly higher than those of nonovulating ovaries (VI, FI, and VFI, all P < .001), with the largest discrepancies during the luteal phase. Hormonally suppressed ovaries had significantly lower vascularity throughout the cycle (VI, P < .002; FI, P < .001; VFI, P < .007). The vascular indices of all groups appeared to drop during the late follicular period and then rise again. Conclusions. The VI would suffice as the principal vascular parameter for 3D power Doppler analysis. Preovulatory scans may be more useful for distinguishing pathologic vascularization. Hormonally suppressed ovaries have significantly lower vascularity throughout the cycle. Normal‐appearing ovaries with vascular indices above the normal ranges established by these data may warrant further investigation.     

Detection of Tumor‐Associated Neoangiogenesis by Doppler Ultrasonography During Early‐Stage Ovarian Cancer in Laying Hens

Objective. Tumor‐associated neoangiogenesis (TAN) is one of the earliest events in ovarian tumor growth and represents a potential target for early detection of ovarian cancer (OVCA). Because it is difficult to identify patients with early‐stage OVCA, the goal of this study was to explore a spontaneous animal model of in vivo ovarian TAN associated with early‐stage OVCA detectable by Doppler ultrasonography (DUS). Methods. White Leghorn laying hens were scanned transvaginally at 15‐week intervals up to 45 weeks. Gray scale ovarian morphologic characteristics and Doppler indices were recorded. Hens were euthanized at diagnosis for ultrasonographic morphologic/vascular abnormalities or at the end of the study (those that remained normal). Ovarian morphologic and histologic characteristics were evaluated. Vascular endothelial growth factor (VEGF) and α_vβ₃‐integrin expression was assessed by immunohistochemical analysis. Doppler ultrasonographic observations were compared with histologic and immunohisto‐chemical findings to determine the ability of DUS to detect ovarian TAN. Results. Significant changes in ovarian blood flow parameters were observed during transformation from normal to tumor development in the ovary (P < .05). Tumor‐related changes in ovarian vascularity were identified by DUS before the tumor became detectable by gray scale imaging. Increased expression of VEGF and α_vβ₃‐integrins was associated with tumor development. Ovarian TAN preceded tumor progression in hens. Conclusions. The results suggest that ovarian TAN may be an effective target for the detection of early‐stage OVCA. The laying hen may also be useful for studying the detection and inhibition of ovarian TAN using various means, including the efficacy of contrast agents, targeted molecular imaging, and antiangiogenic therapies.     

What Does 2‐Dimensional Imaging Add to 3‐ and 4‐Dimensional Obstetric Ultrasonography?

OBJECTIVE: The purpose of this study was to determine whether 2-dimensional (2D) ultrasonography adds diagnostic information to that provided by the examination of 3-dimensional/4-dimensional (3D/4D) volume data sets alone. METHODS: Ninety-nine fetuses were examined by 3D/4D volume ultrasonography. Volume data sets were evaluated by a blinded independent examiner who, after establishing an initial diagnostic impression by 3D/4D ultrasonography, performed a 2D ultrasonographic examination. The frequency of agreement and diagnostic accuracy of each modality to detect congenital anomalies were calculated and compared. RESULTS: Fifty-four fetuses with no abnormalities and 45 fetuses with 82 anomalies diagnosed by 2D ultrasonography were examined. Agreement between 3D/4D and 2D ultrasonography occurred for 90.4% of the findings (123/136; intraclass correlation coefficient, 0.834; 95% confidence interval, 0.774-0.879). Six anomalies were missed by 3D/4D ultrasonography when compared to 2D ultrasonography (ventricular septal defect [n = 2], interrupted inferior vena cava with azygous continuation [n = 1], tetralogy of Fallot [n = 1], horseshoe kidney [n = 1], and cystic adenomatoid malformation [n = 1]). There were 2 discordant diagnoses: transposition of the great arteries diagnosed as a double-outlet right ventricle and pulmonary atresia misinterpreted as tricuspid atresia on 3D/4D ultrasonography. One case of occult spinal dysraphism was suspected on 3D ultrasonography but not confirmed by 2D ultrasonography. When compared to diagnoses performed after delivery (n = 106), the sensitivity and specificity of 3D/4D ultrasonography (92.2% [47/51] and 76.4% [42/55], respectively) and 2D ultrasonography (96.1% [49/51] and 72.7% [40/55]) were not significantly different (P = .233). CONCLUSIONS: Information provided by 2D ultrasonography is consistent, in most cases, with information provided by the examination of 3D/4D volume data sets alone.     

Comparison of 3‐ and 2‐Dimensional Sonographic Techniques for Counting Ovarian Follicles

Objective. The purpose of this study was to compare 3‐dimensional (3D) and 2‐dimensional (2D) ovarian follicle counts and 3D counts using stored volumes between experienced and inexperienced operators. Methods. Follicles larger than 5 mm were counted on 1 randomly selected ovary. Two‐dimensional follicle counts were compared with stored 3D volumes by the same experienced operator (registered diagnostic medical sonographer [RDMS]). Counts using 3D stored data were compared between the experienced operator and inexperienced operator (principal investigator [PI]). The mean difference in follicle counts was computed, and a 1‐sample Student t test was performed to test the hypothesis that the mean of the differences was 0. Comparison of the 2 methods and observers by Bland‐Altman plots was used to determine any systematic differences based on the total number of follicles per selected ovary. Results. Mean differences differed from 0 (P < .005) for all 3 comparisons: 2D RDMS versus 3D RDMS, 2D RDMS versus 3D PI, and 3D RDMS versus 3D PI. For the comparison of 2D versus 3D counts done by the RDMS, 5 ovaries (10%) had a difference of more than 5 follicles counted; for the 2D RDMS versus 3D PI, 11 ovaries (22%) had a difference of more than 5 follicles; for the 3D RDMS versus 3D PI, 8 ovaries (16%) had a difference of more than 5 follicles. Mean differences in counts ranged 0.29 to 1.04 for ovaries with 10 or fewer follicles compared with 3.94 to 9.00 for ovaries with more than 10 follicles. Conclusions. Follicle counts using 3D volumes were similar to 2D counts, and 3D follicle counts done by an inexperienced operator were similar to counts done by an experienced sonographer.     

Use of Multiplanar 3‐Dimensional Ultrasonography for Prenatal Sex Identification

Objective. Determination of fetal sex is an important part of detailed second‐trimester ultrasonography. This task can be hindered by the fetal position, a low amniotic fluid volume, and advanced gestational age. Identification of fetal sex is further important in multiple gestations and prior histories of indeterminate‐sex pregnancies. The goal of the study was to compare the effectiveness of 2‐dimensional ultrasonography (2DUS) versus 3‐dimensional ultrasonography (3DUS) at sex identification and to determine how genitalia measurements taken with 3DUS technology compare with measurements taken with 2DUS. Methods. A total of 111 patients at or beyond 16 weeks' gestation were recruited. Assignments of fetal sex using 2DUS and 3DUS were compared by the test of proportions. The actual neonatal sex was obtained after delivery. Given such small number of misdiagnoses by either 2DUS or 3DUS, the accuracies of the two modalities were not found to be statistically distinguishable from one another (P = .5585). The penile length, scrotal width, and bilabial diameter according to gestational age were measured and compared with previously published 2DUS data by t tests. Results. Sexes were assigned and interpreted in 65 cases. Ranges of genitalia measurements were plotted against gestational age and were found to be comparable with published data. There was a dramatic difference between the bilabial diameter and scrotal width with advancing gestational age that made sex determination much easier in the third trimester. Conclusions. Although 3DUS did not have better prediction of fetal sex when compared with 2DUS, it may be a useful tool in conjunction with traditional imaging techniques in assigning fetal sex.     

A Method for Assessing the Microvasculature in a Murine Tumor Model Using Contrast‐Enhanced Ultrasonography

Objective. The purpose of this study was to develop a method for assessing tumor vascularity in a preclinical model of breast cancer using contrast‐enhanced ultrasonography. Methods. Eight mice were injected with 67NR breast cancer cells on their hind limbs and imaged with ultrasonography 8 days later. Mice were injected with an ultrasound contrast agent (UCA), and a sequence of images of the resultant backscattered echoes was recorded before and after high‐power “destruction” pulses for each of multiple parallel planes. From these, data maps of the maximum contrast enhancement (within each time course) were constructed for each pixel, which enabled reconstruction of high‐resolution coregistered sections into a 3‐dimensional (3D) volume reflecting tumor vascularity. Additional studies were performed to determine the duration and repeatability of image enhancement, and images were correlated with conventional 3D power Doppler measurements. Results. The lifetime of the UCA in vivo was found to be 4.3 ± 1.09 minutes (mean ± SD). The 3D contrast‐enhanced ultrasonographic technique produced images that correlated well with power Doppler images in specific regions but also depicted additional regions of flow surrounding the power Doppler signal. The mean correlation coefficient between voxel measurements of the central slice for each animal was 0.64 ± 0.07 (P < .01). In addition, sequential studies in each animal were reproducible. Conclusions. A method producing high‐resolution volumetric assessments of tumor vascularity in a preclinical model of breast cancer is shown that correlates with other ultrasonographic measures of blood flow, which may provide greater sensitivity to the microvasculature.     

Comparison of Estimated Fetal Weights Using Volume and 2‐Dimensional Sonography and Their Relationship to Neonatal Markers of Fat

Objective. The purpose of this study was to compare the accuracy of traditional 2‐dimensional sonographically estimated fetal weight (EW2D) with 3‐dimensional volume‐based estimated fetal weight (EW3D) and to evaluate the relationship between fetal limb volume, birth weight, and markers of neonatal adiposity. Methods. Fifty singleton pregnancies at 32 to 42 weeks' gestation underwent sonographic evaluation within 48 hours of delivery. We compared the accuracy of the EW2D and EW3D in the prediction of birth weight. The Ponderal index, sum of all skin fold measurements, estimated neonatal fat mass, and percent body fat were calculated. Paired t tests, simple regression analyses, a χ² test, and the Steiger z test were used where appropriate. P < .05 was considered significant. Results. The mean birth weight ± SD was 3130 ± 589 g at 38.8 ± 2.1 weeks. The EW2D (r² = 0.66) and EW3D (r² = 0.76) estimates were both correlated with birth weight. The birth weight and neonatal fat mass were more highly correlated with the sonographically based thigh volume (r² = 0.67 and 0.61) than femur length (r² = 0.41 and 0.37). The mean percent error between EW2D and birth weight was larger (?3.3% ± 11.6%) than the mean percent error of EW3D (0.7% ± 9.2%; P = .0004). Conclusions. Sonographically based fetal limb volumes, especially the fractional thigh volume, reflect neonatal fat mass and are better correlated with birth weight.     

Prenatal Surveillance of Bronchopulmonary Sequestration Using 3‐Dimensional Ultrasonography

Objective. The purpose of this study was to assess the growth of fetal lung lesions using 3‐dimensional ultrasonography (3DUS) and to note the clinical outcomes of infants with congenital bronchopulmonary sequestration (BPS) diagnosed prenatally. Methods. Twenty‐two cases of intrathoracic BPS diagnosed prenatally occurred between May 2005 and September 2008. The volume of the BPS lesion (V_mass) and the volume of the fetal chest (V_chest) were measured with the 3DUS software Virtual Organ Computer‐Aided Analysis (VOCAL; GE Healthcare, Kretztechnik, Zipf, Austria). The clinical outcomes of all cases were recorded. Results. Among 22 cases with fetal BPS, 8 were terminated, and 2 were lost to follow‐up. The growth pattern of the BPS lesions was assessed in 12 live‐born cases with 2 or 3 3DUS measurements per case. There was no statistically significant difference between the V_mass (P = .859) and V_mass/V_chest (P = .078) at 19 to 24 weeks' gestational age (WGA) and greater than 24 to 30 WGA, but there was a statistically significant difference between the V_mass (P = .010) and V_mass/V_chest (P = .008) at greater than 24 to 30 WGA and greater than 30 to 39 WGA. The lung lesion resolved spontaneously before birth in 4 fetuses and postnatally in 2 infants. All 12 fetuses survived to term without any prenatal intervention, were born without any evidence of neonatal respiratory impairment, and did not undergo surgical resection of the mass. Conclusions. Our data showed that fetuses with BPS had a favorable clinical outcome, and the pulmonary mass decreased during late pregnancy and resolved spontaneously. Three‐dimensional ultrasonography with VOCAL provides a useful method for assessing the growth of pulmonary lesions.     

Three‐Dimensional Color‐Coded Duplex Sonography for Assessment of the Vertebral Artery Origin and Vertebral Artery Stenoses

Objective . The aim of the study was to assess the potential of 3‐dimensional (3D) color‐coded duplex sonography (CDS) for evaluation of the vertebral artery origin and stenoses in this location. Methods. To compare 2‐dimensional (2D) and 3D CDS, both techniques were performed in 25 healthy volunteers and in 18 patients with 21 stenoses of the vertebral artery origin. Stenoses were graded in line with hemodynamic criteria on 2D CDS and according to North American Symptomatic Carotid Endarterectomy Trial criteria on 3D CDS. In 6 patients, digital subtraction angiography (DSA) was performed additionally. Stenoses were graded according to North American Symptomatic Carotid Endarterectomy Trial criteria and compared with 2D and 3D sonographic data. Results. Overall correlation of both sonographic techniques concerning the grading of the stenoses was good (r = 0.69; P < .01). The interobserver correlation for assessment of stenoses by means of 3D CDS was high (r = 0.94; P < .01). Three‐dimensional CDS correlated excellently with DSA in 3 of 6 patients but showed only intermediate or no correlation in the remaining 3 patients. In contrast, spatial information on the stenotic morphologic characteristics was always very comparable with the results obtained by DSA. Conclusions. Three‐dimensional CDS represents a valuable tool for assessment of the origin of the vertebral artery, allowing important morphologic information on stenoses in this location. For grading of stenoses of the vertebral artery origin, 3D information should be combined with hemodynamic criteria obtained by spectral Doppler imaging in 2D CDS. Three‐dimensional CDS could be a valuable tool before interventional procedures of the proximal vertebral artery, saving time and avoiding iodinated contrast agents.     

Usefulness of Renal Volume Measurements Obtained by a 3‐Dimensional Sonographic Transducer With Matrix Electronic Arrays

Objective. The purpose of this study was to examine the feasibility of 3‐dimensional (3D) sonography using a matrix array transducer to measure renal volume. Methods. One hundred consecutive patients with a normal serum creatinine level and kidney appearance on computed tomography (CT) performed within 2 months before sonography were enrolled in this study. Two hundred individual renal volumes were blindly obtained by the ellipsoid formula, the stacked ellipse method, the voxel count method using routine 2‐dimensional (2D) sonographic data, 3D sonographic data using a matrix array transducer, and CT data, respectively. The voxel count method was validated as the reference standard by the water displacement method in 10 cadaveric pig kidneys (r = 0.99; P < .001). Renal volumes determined by 2D and 3D sonography were compared with volumes determined by CT. Results. Volumes determined by 2D sonography were significantly lower than those determined by CT (P < .001) but similar to those determined by 3D sonography (P = .78). The percent volume error of 3D sonography (mean ± SD, ?2.2% ± 3.7%) was significantly lower than that of 2D sonography (?15.7% ± 11.8%) with CT as the standard (P < .001). The correlation coefficient between 3D sonography and CT (r = 0.98; P < .0001) was better than that between 2D sonography and CT (r = 0.83; P < .0001). In addition, Bland‐Altman analysis revealed that the limits of agreement between 3D sonography and CT (?9.7% to 5.1%) were narrower than those between 2D sonography and CT (?45.6% to 9.8%). Conclusions. Three‐dimensional sonography with a matrix array transducer can significantly reduce renal volume measurement errors and offers a reliable means of determining renal volumes.     

Three‐Dimensional Ultrasonographic Bladder Volume Measurement

Objective. The purpose of this study was to investigate the reliability of Virtual Organ Computer‐Aided Analysis (VOCAL; GE Healthcare, Kretztechnik, Zipf, Austria) using the 4 standard rotation steps to measure the bladder volume with 3‐dimensional (3D) ultrasonography. Methods. Using the 4 standard rotation steps of VOCAL, 2 independent observers made 3D volume measurement data sets from the urinary bladder (n = 180). Sets of 30, 20, 12, and 6 planes were obtained from the sequential rotations of 6°, 9°, 15°, and 30°, respectively. The internal contours of the bladders were determined manually. Reliability was evaluated with the intraclass correlation coefficient (ICC), and Bland‐Altman plots were generated to examine bias and agreement. One‐way analysis of variance was used to compare bladder volume measurements between the angles. P < .05 was considered statistically significant. Results. A high degree of reliability was observed between pairs of different rotation angles (ICC, 0.994–0.999). There was good agreement between all pairs of different rotation angles, with percentages of the mean difference ranging from ?0.9% to 1.8%. No significant difference was found for bladder volume measurements by the VOCAL technique with varying rotation steps. Intraobserver and interobserver reliabilities were high (ICC, 0.994–0.998). Conclusions. Urinary bladder volume measurement by the VOCAL technique using different rotation steps is highly reliable. A plane rotation of 30° produces the fastest result.     

Comparison of B‐Mode Ultrasound, 3‐Dimensional Ultrasound,and Magnetic Resonance Imaging Measurements of Carotid Atherosclerosis

Objective. We compared the intraobserver and interscan variability of carotid atherosclerosis measured using B‐mode ultrasound for quantifying intima media thickness (IMT), 3‐dimensional ultrasound (3DUS) for quantifying vessel wall volume (VWV) and total plaque volume (TPV), and magnetic resonance imaging (MRI) for measuring VWV. We also evaluated the associations of these measurements and sample sizes required to detect specific changes in patients with moderate atherosclerosis. Methods. Ten patients were evaluated with B‐mode ultrasound, MRI, and 3DUS twice within 14 ± 2 days. Measurements of IMT, MRI VWV, 3DUS VWV, and 3DUS TPV were performed by single observers using manual (VWV and TPV) and semiautomated (IMT) segmentation. Results. Intraobserver coefficients of variation were 3.4% (IMT), 4.7% (3DUS VWV), 6.5% (MRI VWV), and 23.9% (3DUS TPV). Interscan coefficients of variation were 8.1% (MRI VWV), 8.9% (IMT), 13.5% (3DUS VWV), and 46.6% (3DUS TPV). Scan‐rescan linear regressions were significant for 3DUS TPV (R² = 0.57), 3DUS VWV (R² = 0.59), and IMT (R² = 0.75) and significantly different (P < .05) for MRI VWV (R² = 0.87). Conclusions. B‐mode ultrasound‐derived IMT provided the highest intraobserver and interscan reproducibility. Three‐dimensional measurements of VWV derived from 3DUS and MRI provided both high sensitivity and high intraobserver and interscan reliability.     

[68Ga]‐HP‐DO3A‐nitroimidazole: a promising agent for PET detection of tumor hypoxia

The goal of this study is to evaluate a new ⁶⁸Ga‐based imaging agent for detecting tumor hypoxia using positron emission tomography (PET). The new hypoxia targeting agent reported here, [⁶⁸Ga]‐HP‐DO3A‐nitroimidazole ([⁶⁸Ga]‐HP‐DO3A‐NI), was constructed by linking a nitroimidazole moiety with the macrocyclic ligand component of ProHance®, HP‐DO3A. The hypoxia targeting capability of this agent was evaluated in A549 lung cancer cells in vitro and in SCID mice bearing subcutaneous A549 tumor xenografts. The cellular uptake assays showed that significantly more [⁶⁸Ga]‐HP‐DO3A‐NI accumulates in hypoxic tumor cells at 30, 60 and 120 min than in the same cells exposed to 21% O₂. The agent also accumulated in hypoxic tumors in vivo to give a tumor/muscle ratio (T/M) of 5.0 ± 1.2 (n = 3) as measured by PET at 2 h post‐injection (p.i.). This was further confirmed by ex vivo biodistribution data. In addition, [⁶⁸Ga]‐HP‐DO3A‐NI displayed very favorable pharmacokinetic properties, as it was cleared largely through the kidneys with little to no accumulation in liver, heart or lung (%ID/g < 0.5%) at 2 h p.i. The specificity of the agent for hypoxic tissues was further validated in a comparative study with a control compound, [⁶⁸Ga]‐HP‐DO3A, which lacks the nitroimidazole moiety, and by PET imaging of tumor‐bearing mice breathing air versus 100% O₂. Given the commercial availability of cGMP ⁶⁸Ge/⁶⁸Ga generators and the ease of ⁶⁸Ga labeling, the new agent could potentially be widely applied for imaging tumor hypoxia prior to radiation therapy. Copyright © 2015 John Wiley & Sons, Ltd.     

Three‐Dimensional Power Doppler Vascular Sonographic Sampling for Predicting Ovarian Cancer in Cystic‐Solid and Solid Vascularized Masses

Objective. The purpose of this study was to explore the role of 3‐dimensional (3D) power Doppler (PD) sonography to discriminate between benign and malignant cystic‐solid and solid vascularized adnexal masses and to define cutoff values for 3D PD indices to be used in a clinical setting. Methods. A total of 143 consecutive women (mean age, 50.4 years; range, 17–82 years) with diagnoses of cystic‐solid or solid vascularized adnexal masses on B‐mode and 2‐dimensional PD sonography were evaluated by 3D PD sonography before surgery. Three‐dimensional PD sonography was used to assess vascularization within papillary projections and solid areas with a virtual organ computer‐aided analysis program. Three‐dimensional PD vascular indices (vascularization index [VI], flow index [FI], and vascularization‐flow index [VFI]) were automatically calculated. A definitive histologic diagnosis was obtained in each case. Results. A total of 113 masses (74%) were malignant, and 39 (26%) were benign. Morphologic evaluation revealed 30 unilocular solid masses (19.7%), 43 multilocular solid masses (28.3%), and 79 mostly solid masses (52%). The mean VI (9.365% versus 3.3%; P < .001), FI (34.318 versus 28.794; P < .001), and VFI (3.233 versus 1.15; P < 0.01) were significantly higher in malignant tumors. No differences were found in the resistive index, pulsatility index, and peak systolic velocity. Receiver operating characteristic analysis revealed an area under the curve of 0.77 (95% confidence interval, 0.69–0.85), 0.71 (0.60–0.81), and 0.75 (0.66–0.83) for the VI, FI and VFI, respectively. For reducing the false‐positive rate by almost one‐third, sensitivity values for the VI (cutoff, 1.556%), FI (25.212), and VFI (0.323) were 92%, 95%, and 93%, respectively. Conclusions. Three‐dimensional PD vascular indices could be helpful for reducing the false‐positive rate in cystic‐solid and solid vascularized adnexal masses.