OBJECTIVE: Transoral robotic surgery (TORS) is a challenging procedure due to its small workspace and complex anatomy. Ultrasound (US) image guidance has the potential to improve surgical outcomes, but an appropriate method for US probe manipulation has not been defined. This study evaluates using an additional robotic (4th) arm on the da Vinci Surgical System to perform extracorporeal US scanning for image guidance in TORS.
METHODS: A stereoscopic imaging system and da Vinci-compatible US probe attachment were developed to enable control of the extracorporeal US probe from the surgeon console. The prototype was compared to freehand US by nine operators in three tasks on a healthy volunteer: (1) identification of the common carotid artery, (2) carotid artery scanning, and (3) identification of the submandibular gland. Operator workload and user experience were evaluated using a questionnaire.
RESULTS: The robotic US tasks took longer than freehand US tasks (2.09x longer; p = 0.001 ) and had higher operator workload (2.12x higher; p = 0.004 ). However, operator-rated performance was closer (avg robotic/avg freehand = 0.66; p = 0.017 ), and scanning performance measured by MRI-US average Hausdorff distance provided no statistically significant difference.
CONCLUSIONS: Extracorporeal US scanning for intraoperative US image guidance is a convenient approach for providing the surgeon direct control over the US image plane during TORS, with little modification to the existing operating room workflow. Although more time-consuming and higher operator workload, several methods have been identified to address these limitations.

There\'s a paucity of robust normal fractional limb and organ volume standards from a large and diverse ethnic population. The Fetal 3D Study was designed to develop research and clinical applications for fetal soft tissue and organ volume assessment. The NICHD Fetal Growth Studies (2009-2013) collected 2D and 3D fetal volumes. In the Fetal 3D Study (2015-2019), sonographers performed longitudinal 2D and 3D measurements for specific fetal anatomical structures in research ultrasounds of singletons and dichorionic twins. The primary aim was to establish standards for fetal body composition and organ volumes, overall and by maternal race/ethnicity, and determine whether these standards vary for twins versus singletons. We describe the study design, methods, and details about reviewer training. Basic characteristics of this cohort, with their corresponding distributions of fetal 3D measurements by anatomical structure, are summarized. This investigation is responsive to critical data gaps in understanding serial changes in fetal subcutaneous fat, lean body mass, and organ volume in association with pregnancy complications. In the future, this cohort can answer critical questions regarding the potential influence of maternal characteristics, lifestyle factors, nutrition, and biomarker and chemical data on longitudinal measures of fetal subcutaneous fat, lean body mass, and organ volumes.

This study aims to evaluate the role of intraoperative transvaginal three-dimensional ultrasound (3DUS) during hysteroscopic metroplasty. This is a prospective cohort of consecutive patients with septate uterus undergoing hysteroscopic metroplasty with intraoperative transvaginal 3DUS guidance compared to a historical control group of patients undergoing hysteroscopic metroplasty without 3DUS. We conducted our research in a tertiary care university hospital in Rome, Italy. This study involved nineteen patients undergoing 3DUS-guided hysteroscopic metroplasty for recurrent abortion or infertility compared to 19 age-matched controls undergoing metroplasty without 3DUS guidance. During hysteroscopic metroplasty, 3DUS was performed in the study group when the operator considered the procedure to be completed, according to standards of operative hysteroscopy. If 3DUS diagnosed a residual septum, the procedure was continued until a 3DUS diagnosis of a normal fundus was obtained. The patients were followed with a 3DUS performed 3 months after the procedure. The numbers of complete resections (residual septum absent), suboptimal resections (measurable residual septum of less than 10 mm), and incomplete resections (residual septum > 10 mm) in the intraoperative 3DUS group were compared to the numbers in the control group with no intraoperative 3DUS. At follow-up, measurable residual septa were obtained in 0% of the patients in the 3DUS-guided group versus 26% in the control group (p = 0.04). Residual septa of > 10 mm were obtained in 0% of the 3DUS group versus 10.5% in the control group (p = 0.48). Intraoperative 3DUS reduces the incidence of suboptimal septal resections at hysteroscopic metroplasty.

OBJECTIVE: Thyroid nodules are extremely common, with prevalence rate up to 68%, yet only 7-15% of these are malignant. Many nodules require surveillance and 2-dimensional ultrasound (2D US) is used. Issues include the huge workload of obtaining and labeling images and difficulty comparing sizes of nodules over time due to large inter-operator variability. Inaccuracies may result in unnecessary FNAC or missed diagnosis of malignant nodules.
METHODS: We compared two techniques: freehand plain 2D US against freehand 2D US with gyroscopic guidance, both followed by 3D reconstruction using software. We measured the volume of nodules and a normal thyroid gland.
RESULTS: We found 2D US with gyroscopic guidance to be superior to plain 2D US as 3D reconstructions of greater accuracy are produced. The volume of the thyroid lobe measured 8.42 cm3 ± 0.94 was reasonably close to the normal average volume. However, the measured volume of the ellipsoidal nodule by the software is 8.69 cm3 ± 0.97 while the measured volume of the spherical nodule is 7.09 cm3 ± 0.79. As the expected volume of the nodules were 4.24cm3 and 4.19 cm3 respectively, the measured volume of the nodule was not accurate. The time taken to characterise nodules was reduced greatly from over 30 min in usual procedure to less than 10 min.
CONCLUSIONS: We find 3D US promising for evaluating size of thyroid nodules, with potential to study other TIRAD characteristics. Freehand 2D US with gyroscopic guidance shows the most promise for producing reliable, accurate and faster 3D reconstructions of thyroid nodules.

The Achilles tendon (AT) exhibits volume changes related to fluid flow under acute load which may be linked to changes in stiffness. Fluid flow provides a mechanical signal for cellular activity and may be one mechanism that facilitates tendon adaptation. This study aimed to investigate whether isometric intervention involving a high level of load duration and intensity could maximize the immediate reduction in AT volume and stiffness compared with interventions involving a lower level of load duration and intensity. Sixteen healthy participants (12 males, 4 females; age 24.4±9.4 years, body mass 70.9±16.1 kg, height 1.7±0.1 m) performed three isometric interventions of varying levels of load duration (2 s and 8 s) and intensity (35% and 75% maximal voluntary isometric contraction) over a 3 week period. Freehand 3D ultrasound was used to measure free AT volume (at rest) and length (at 35%, 55% and 75% of maximum plantarflexion force) pre- and post-interventions. The slope of the force-elongation curve over these force levels represented individual stiffness (N mm-1). Large reductions in free AT volume and stiffness resulted in response to long-duration high-intensity loading whilst less reduction was produced with a lower load intensity. In contrast, no change in free AT volume and a small increase in AT stiffness occurred with lower load duration. These findings suggest that the applied load on the AT must be heavy and sustained for a long duration to maximize immediate volume reduction, which might be an acute response that enables optimal long-term tendon adaptation via mechanotransduction pathways.

The objective was to determine whether standardized, intraoperative urethral measurement improves retropubic mid-urethral sling (RPMUS) positioning and if the intraoperative position remains stable at 2 weeks postoperatively.
Participants undergoing a RPMUS were randomized to mid-urethral placement as per usual surgical care (no Foley catheter measurement, no-FCM) vs urethral mid-point Foley catheter measurement (FCM). The primary outcomes were RPMUS location as determined by 2D and 3D ultrasound 2 weeks postoperatively (as percentage from urethral meatus - relative to the urethral length) and intraoperatively following the RPMUS placement.
Forty-four women enrolled, underwent RPMUS, and provided baseline data and intraoperative ultrasound measurements; of these, 36 (82%) had interpretable intraoperative and postoperative ultrasound measurements. Demographic data were similar in the two groups. The mean RPMUS mid-point was 57 % and 55 % in measured and controls (p = 0.685); this same measurement was relatively unchanged at 2 weeks postoperatively at 57% and 54% respectively (p = 0.538). Very much and much improvement was reported on the PGI-I by 84% and 85% of participants in the FCM and no-FCM groups respectively.
Intraoperative RPMUS position at 2 weeks after surgery is similar to the intraoperative position. Compared with usual surgical care, intraoperative measurement of urethral mid-point with a Foley catheter did not affect RPMUS sling position.

BACKGROUND: To investigate the reproducibility of first-trimester fetal organ volume measurements using three-dimensional (3D) ultrasound and a Virtual Reality system.
METHODS: Within a population-based prospective cohort study, 3D ultrasound datasets of 25 first-trimester fetuses were collected by three sonographers. We used the V-scope application to perform Virtual Reality volume assessments of the fetal heart, lungs, and kidneys. All measurements were performed by two independent researchers.
RESULTS: Intraobserver analyses for volume measurements of the fetal heart, lungs, and kidneys showed intraclass correlation coefficients ≥0.86, mean differences ≤8.3%, and coefficients of variation ≤22.8%. Interobserver analyses showed sufficient agreement for right lung volume measurements, but consistent measurement differences between observers for left lung, heart, and kidney volume measurements (p-values <0.05).
CONCLUSIONS: We observed sufficient intraobserver reproducibility, but overall suboptimal interobserver reproducibility for first-trimester fetal heart, lung, and kidney volume measurements using an innovative Virtual Reality approach. In the current stage, these measurements might be promising for the use in research settings. The reproducibility of the measurements might be further improved by novel post-processing algorithms.

UNASSIGNED: 4D (3D + time) indices of tissue impedance using power Doppler (PD) ultrasound (US) can be measured with spatial-temporal image correlation (STIC) imaging. We wished to evaluate their repeatability and their influence under changes to US machine settings and regional differences within the placenta.
UNASSIGNED: A total of 46 healthy women were recruited at 20-34 weeks of gestation. A total of 9940 3D frames from 644 4D data sets were analysed providing both 3D and 4D indices of vascularity. 4D vs. 3D indices were compared with different machine settings, across the cardiac cycle and in the different placenta regions to assess regional variability.
UNASSIGNED: 3D and 4D indices significantly decreased as wall motion filter (WMF) was increased (P < 0.001). Repeatability decreased as WMF increased (ICC; low1 = 0.80; high1 = 0.60). Indices were significantly lower at the maternal aspect (P = 0.002-0.009) of the placenta and showed less repeatability (ICC; 0.42-0.79) than the fetal aspect (ICC 0.49-0.88). 4D repeatability was good in the central region (ICC 0.80-0.81) but poor in the periphery (ICC 0.45-0.59), while 3D indices were good and comparable between regions (ICC; 0.80 central; 0.81 peripheral).
UNASSIGNED: This study supports the future use of WMF \'low1\' and PD to generate more reliable 4D indices values. For 3D indices, HD Flow may improve Doppler signal sensitivity. Regarding placental regional variability, the fetal plate and the central region demonstrated more repeatable 4D indices. 4D PD indices have potential to overcome the limitations of VOCAL™ indices and provide an internally standardised measure of localised impedance in vascular beds.

OBJECTIVE: To compare, in terms of anatomical, functional, and sexual aspects, two types of treatment for women with vaginal agenesis: progressive dilation or surgical neovaginoplasty.
METHODS: Women with vaginal agenesis underwent either dilation treatment using the Frank method or surgical treatment using the modified Abbé-McIndoe technique with oxidized cellulose. Patients were evaluated 3-6 months after treatment for a follow-up including medical history, physical examination, general satisfaction, clinical aspect of the vagina, Female Sexual Function Index, and three-dimensional pelvic floor ultrasound.
RESULTS: In total, 20 women with vaginal agenesis were included in the present study; nine in the dilation group and 11 in the surgical group. A comparison between the groups (vaginal dilation and surgical neovaginoplasty) showed efficacy in neovagina formation after both treatments, with a statistically significant difference between the pre- and post-treatment periods (P value pre- × post-dilation group <0.0001 and P value pre- × post-surgical group <0.0001). There were no statistical differences in total vaginal length measurements (P value post-dilation × post-surgical = 0.09) or Female Sexual Function Index scores (P = 0.72) after both treatments.
CONCLUSIONS: Both treatments had satisfactory efficacy and positive outcomes for patients with vaginal agenesis concerning anatomical, functional, and sexual aspects, with minimum complications in the surgical group. Dilation treatment can remain the first-line therapy.

OBJECTIVE: Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT).
METHODS: Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models.
RESULTS: Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT.
CONCLUSIONS: Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.