Transvaginal three-dimensional ultrasound assessment of embryonic genital tubercle at 8-10+6 weeks of gestation.

OBJECTIVES: To assess embryonic genital tubercle using transvaginal three-dimensional (3D) ultrasound at 8-10+6 weeks of gestation. METHODS: One-hundred and two transvaginal 3D ultrasound scans were performed for first-trimester dating at 8-10+6 weeks of gestation. The genital tubercle angle (GTA) and genital tubercle length (GTL) were measured with a mid-sagittal view of the embryo using the 3D ultrasound multiplanar mode. Intra- and inter-observer agreements regarding GTA and GTL were also assessed with Bland-Altman plots and intra- and inter-correlation coefficients. RESULTS: There were no significant differences in GTA between male and female embryos at 8, 9, 10 weeks, or 8-10+6 weeks of gestation, respectively. There were also no significant differences in GTL between male and female embryos at 8, 9, 10 weeks, or 8-10+6 weeks of gestation, respectively. However, GTL increased linearly with advancing gestation (r=0.8276, p<0.00001). Mean GTL (SD) values at 8, 9, and 10 weeks were 0.833 mm (0.274), 1.623 mm (0.262), and 2.152 mm (0.420), respectively (p<0.001). Intra- and inter-reproducibilities of GTA and GTL were excellent. The intra- and inter-correlation coefficients of GTA and GTL were 0.964 and 0.995, and 0.996 and 0.9933, respectively. CONCLUSIONS: The genital tubercle could be identified using transvaginal 3D ultrasound at 8-10+6 weeks of gestation. However, sex differentiation could not be performed at this age. The genital tubercle linearly developed with advancing gestation during the mid-first trimester of pregnancy.

Color Doppler, HDlive, and HDlive Silhouette features of an umbilical cord cyst before 11 weeks of gestation: Diagnostic value.

OBJECTIVE: We describe transvaginal color Doppler, HDlive, and HDlive Silhouette features of an umbilical cord cyst (UCC) before 11 weeks of gestation. METHODS: In this cohort study, 135 transvaginal dating scans were performed at 7 to 10 + 6 weeks of gestation, and 17 UCCs were identified (12.6%). UCC was evaluated using color Doppler, HDlive, and HDlive Silhouette. The clinical characteristics, pregnancy courses, and outcomes were also investigated. RESULTS: UCC location was on the fetal side in six cases, at the free loop in 10 cases, and on the placental side in one case. There were seven single and 10 multiple cysts. Cyst diameters ranged from 3.3 to 11.3 mm (mean, 5.6; standard deviation, ±2.1). Blood flow inside the cyst was noted in three cases (17.6%). HDlive clearly showed the spatial relationships among UCC, the umbilical cord, midgut herniation, yolk sac, and embryo. Location of UCC could be clearly identified with HDlive. HDlive Silhouette showed central cysts inside UCCs in seven cases (41.2%). HDlive Silhouette also clearly demonstrated the sac of midgut herniation in the umbilical cord in 12 cases (70.6%). All UCCs resolved before 15 weeks (mean, 11.1 weeks; standard deviation, ±1.5). All fetuses with UCCs showed good neonatal outcomes. CONCLUSION: The incidence of UCC was high compared with that in previous reports. Color Doppler, HDlive, and HDlive Silhouette may provide information on the nature and origin of UCCs before 11 weeks of gestation. UCC before 11 weeks of gestation may be a common, transient, and benign finding.

Isolated small ventricular septal defects in utero: HDlive Flow with spatiotemporal image correlation and HDlive Silhouette case study.

Purpose: To demonstrate shunt flow through small ventricular septal defects (VSDs) using HDlive Flow with spatiotemporal image correlation (STIC) and HDlive Silhouette. Methods: Four cases of isolated small VSDs were evaluated using colour Doppler, and HDlive Flow with STIC and HDlive Silhouette. Results: HDlive Flow with STIC and HDlive Silhouette can improve the ability to depict shunt flow through small VSDs compared with colour Doppler. Conclusion: This technique provides information on spatial recognition of the shunt flow through isolated small VSDs in real time.

Embryonic and fetal tiny pericardial fluid collections at less than 12 weeks of gestation.

OBJECTIVES: To describe embryonic and fetal tiny pericardial fluid collections (PFCs) using transvaginal sonography and HDlive Silhouette at less than 12 weeks of gestation. METHODS: During an 8-month period from November 2021 to June 2022, one-hundred and thirty transvaginal scans were performed for first-trimester dating, and eleven tiny PFCs of the embryo or fetus were identified at 8+4 - 11+3 weeks of gestation (three at 8, six at 9, and two at 11 weeks). HDlive Silhouette features of PFC were evaluated. Their clinical characteristics and outcomes were also investigated. RESULTS: The incidence of tiny PFCs was 8.5 % at less than 12 weeks of gestation. The mean gestational age at the initial examination was 9.5 weeks (SD: ± 0.9). The mean crown-rump length was 25.0 mm (SD: ± 8.5). The mean PFC dimension was 0.8 mm (range: 0.5-1.3, SD: ± 0.2). Pleural effusion was associated with 3 out of 11 PFCs (27.2 %). Ascites was noted in 2 cases (18.2 %). Skin edema was identified in only in 1 case (0.09 %). There was no arrhythmia. Tiny PFC could also be depicted using HDlive Silhouette. First-trimester fetal ultrasound scans at 11 - 13+6 weeks showed no abnormal findings. PFCs resolved until 13 weeks of gestation (Mean: 12 weeks, SD: ± 1.2). All PFC pregnancies resulted in healthy neonates. CONCLUSIONS: The incidence of tiny PFCs was relatively high in early pregnancy. HDlive Silhouette can depict tiny PFCs of the embryo. Tiny PFCs in early gestation are transient, benign findings in utero.

Isolated tortuous ductus arteriosus in a fetus: HDlive Flow with spatiotemporal image correlation (STIC) study.

OBJECTIVES: To describe prevalence, outcome, color Doppler, and HDlive Flow (Silhouette) with spatiotemporal image correlation (STIC) features of isolated tortuous ductus arteriosus in Japanese fetuses at 28-31 + 6 weeks of gestation. METHODS: During a 37-month period, 3,150 fetal screenings were performed at 28-31 + 6 weeks of gestation. Isolated tortuous ductus arteriosus was evaluated using color Doppler and HDlive Flow (Silhouette) with STIC. Prevalence and outcomes were also assessed. RESULTS: There were 22/3,150 fetuses (0.7%) had isolated tortuous ductus arteriosus at 28-31 + 6 weeks of gestation. According to color Doppler and HDlive Flow findings, two types of isolated tortuous ductus arteriosus (Right-angled and Loop shapes) were classified. There were 20 Right-angled and 2 Loop shapes. One fetus with a Right-angled shape was associated with aortic tortuosity. HDlive Flow with STIC revealed spatial relationships of tortuous ductus arteriosus, aortic arch, and descending aorta. All fetuses with isolated tortuous ductus arteriosus had good neonatal outcomes. CONCLUSIONS: The incidence of isolated tortuous ductus arteriosus in Japanese fetuses was low compared with those in previous reports. HDlive Flow with STIC provides precise information for spatial recognition and differentiation of isolated tortuous ductus arteriosus, resulting in two type classifications. Isolated tortuous ductus arteriosus in a fetus may be a transient, benign finding in utero.

HDlive Flow Silhouette with spatiotemporal image correlation for assessment of fetal cardiac structures at 12 to 14 + 6 weeks of gestation.

OBJECTIVES: To assess fetal cardiac structures using HDlive Flow Silhouette with spatiotemporal image correlation (STIC) at 12 to 14 + 6 weeks of gestation, and verify the feasibility of obtaining five cardiac views in the late first and early second trimesters of pregnancy. The fetal cardiac shape and the aspect of the descending aorta were also evaluated. METHODS: Eighty normal fetuses at 12 to 14 + 6 weeks of gestation were studied using trans-abdominal HDlive Flow Silhouette with STIC to assess the feasibility of five fetal cardiac views (frontal, spatial three-vessel, panoramic, posterior, and right lateral views). Target structures in each cardiac view were evaluated. 'Good' was assigned when all structures were noted, 'Fair' when only one structure was missed, and 'Poor' when two and more structures could not be detected. Frequencies of an elongated heart and those of a tortuous descending aorta were counted. RESULTS: Forty-nine fetuses were effectively included in the analysis. Success rates of 'Good' and 'Fair' were significantly higher with spatial three-vessel (p<0.01) and panoramic views (p<0.05). Frequencies of "Elongated heart", "Elongated left ventricle", and "Spherical heart" were 12.2, 6.2, and 81.6%, respectively. Frequencies of "Tortuous descending aorta" and "Straight descending aorta" were 12.2 and 87.8%, respectively. CONCLUSIONS: The feasibility of obtaining fetal five cardiac views using HDlive Flow Silhouette with STIC is good, and this technique provides useful information for evaluating fetal cardiac structures in the late first and early second trimesters of pregnancy.

[Development of an automated method for analysis of Winston-Lutz test results using digital radiography and photostimulable storage phosphor].

Stereotactic radiosurgery (SRS) and radiotherapy (SRT) are intricate techniques that deliver a highly precise radiation dose to a localized target, usually a tumor. At our hospital, we perform SRS and SRT on brain tumors using a linear accelerator (linac) mounted with an external micro multi-leaf system. The Task Group TG-142 Report by the American Association of Physicists in Medicine recommends the coincidence of the radiation and mechanical isocenter to be within ±1 mm. The Winston-Lutz test is commonly used to verify the linac isocenter position: it has the advantages of being a simple method that uses a film or electronic portal imaging device (EPID). However, the film method requires a higher radiation dose, which makes it more time-consuming than the EPID method, and the results are highly dependent on the skills of the observer. The EPID method has certain advantages over the film method, but it has low resolution and can only be used for a few combinations of gantry and couch angles. This prompted us to develop an in-house-designed radiation receptor system based on digital radiography, using a photostimulable storage phosphor and automated analysis algorithm for Winston-Lutz test images using a template-matching technique based on cross-correlation coefficients. Our proposed method shows a maximum average absolute error of 0.222 mm (less than 2 pixels) for 0.5 mm and 1.0 mm displacement from the isocenter toward the inline and crossline directions. Our proposed method is thus potentially useful for verifying the Linac isocenter position with a small error and good reproducibility, as demonstrated by improved accuracy of evaluation.

Automated estimation of number of implanted iodine-125 seeds for prostate brachytherapy based on two-view analysis of pelvic radiographs.

Digital pelvic radiographs are used to identify the locations of implanted iodine-125 seeds and their numbers after insertion. However, it is difficult and laborious to visually identify and count all implanted seeds on the pelvic radiographs within a short time. Therefore, our purpose in this research was to develop an automated method for estimation of the number of implanted seeds based on two-view analysis of pelvic radiographs. First, the images of the seed candidates on the pelvic image were enhanced using a difference of Gaussian filter, and were identified by binarizing the enhanced image with a threshold value determined by multiple-gray level thresholding. Second, a simple rule-base method using ten image features was applied for false positive removal. Third, the candidates for the likely number of a multiply overlapping seed region, which may include one or more seeds, were estimated by a seed area histogram analysis and calculation of the probability of the likely number of overlapping seeds. As a result, the proposed method detected 99.9% of implanted seeds with 0.71 false positives per image on average in a test for training cases, and 99.2% with 0.32 false positives in a validation test. Moreover, the number of implanted seeds was estimated correctly at an overall recognition rate of 100% in the validation test using the proposed method. Therefore, the verification time for the number of implanted seeds could be reduced by the provision of several candidates for the likely number of seeds.