Ultrasound Volume Research Articles

Real-time 3-D reconstruction from multiple simultaneous ultrasound scans for enhanced imaging

Ultrasound imaging offers numerous benefits compared to other modalities, including portability, affordability, and real-time volumetric imaging capabilities. However, its limited field of view hinders image interpretation, significantly limiting its potential clinical applications. This study focuses on creating tomographic ultrasound imaging by automatically registering partially overlapping 3-D ultrasound volumes (coarsely localized in space). This approach can be used to gather a comprehensive field of view of the anatomical area imaged and to enhance the acquired image information. Potential applications involve both tomographic/wide-view imaging using conventional ultrasound probes and future technologies, where multiple ultrasound probes will be able to scan simultaneously the anatomy of interest. This work describes the development of advanced artificial intelligence and image analysis methods to create real-time 3-D anatomical reconstructions of a designated area of interest. Simultaneously (or quasi simultaneously) acquired ultrasound volumes with partial overlap can be spatially aligned using rigid registration, because they present geometrically similar information. We used novel supervised and unsupervised transformers and compared the results with more traditional methods such as mutual information and cross-correlation. This application contributes to creating new imaging processing techniques for ultrasound imaging and making this complex modality more user-friendly and clinically usable.

OC01.07: Automated extraction of standard plane for cervical length measurement from 3D ultrasound volume in pregnant women using transvaginal sonography

OC01.07: Automated extraction of standard plane for cervical length measurement from 3D ultrasound volume in pregnant women using transvaginal sonography

Application of real time shear wave elastography to the differential diagnosis of secondary parathyroid hyperplasia and adenoma.

We aimed to explore the value of ultrasonic elastic imaging in the diagnosis of parathyroid hyperplasia and adenoma in patients with secondary hyperparathyroidism and provide more evidence for clinical treatment. Forty patients who were on dialysis and underwent parathyroid surgery were selected All patients underwent routine ultrasound, ultrasound elasticity examination and blood biochemical examination before surgery, including calcium, phosphorus, parathyroid hormone (PTH), etc. According to postoperative results, adenoma group and hyperplasia group were divided into 2 groups. Receiver operating characteristic curve was drawn to evaluate the diagnostic efficacy and combined diagnostic efficacy of each index. The PTH levels significantly differed between the adenoma and hyperplasia groups (P < .001). The volume and blood flow grades significantly differed between the adenoma and hyperplasia groups (P < .001) The minimum of the adenoma group was 14.62 ± 6.79 kPa, mean was 19.42 ± 6.29 kPa, and maximum was 24.25 ± 6.35 kPa which were significantly different from those in the hyperplasia group (P < .05). The combinations of more than 6 indicators in the diagnosis of parathyroid adenoma resulted in an area under the curve of 0.892 (P < .001), and the sensitivity and specificity were 78.9% and 97.4%, respectively. Shear wave elastography can be used as an effective tool to distinguish secondary parathyroid hyperplasia from adenoma. When combined with PTH, conventional ultrasound blood flow grading and volume measurement, it has higher diagnostic efficacy.

Development of the prosencephalic structures, ganglionic eminence, basal ganglia and thalamus at 11 + 3 to 13 + 6 gestational weeks on 3D transvaginal ultrasound including normative data

ObjectivesTo show the development of ganglionic eminence, basal ganglia and thalamus/hypothalamus in week 11 + 3 to 13 + 6 by transvaginal 3D ultrasound.MethodsTo visualize the prosencephalic structures surrounding the 3rd ventricle, 285 three-dimensional ultrasound volume blocks from 402 fetuses examined were selected in a prospective transvaginal 3D study to compare ultrasound images of ganglionic eminence, basal ganglia, thalamus/hypothalamus with embryological sections. In addition, measurements of the described structures were made in 104 fetuses to quantify the embryological development.ResultsThe sonomorphologic characteristics of ganglionic eminence, basal ganglia and thalamus/hypothalamus are described in 71% of the fetuses examined. Measurements of the structures in 57% of the fetuses, show the following results: axGE ap = 0.17 + 0.112*CRL; axGE/I = 0.888 + 0.048*CRL; axGE/BG = 0.569 + 0.041*CRL; coGE/BG = 0.381 + 0.048*CRL; coTh lat = − 0.002 + 0.135*CRL; coTh/HyT = 3.68 + 0.059*CRL; co3.V lat = 0.54 + 0.008*CRL.ConclusionTransvaginal 3D neurosonography allows visualization and measurement of normal structures in the fetal prosencephalon at 11 + 3 to 13 + 6 weeks of gestation (GW) including details of ganglionic eminence (GE), basal ganglia (BG), and thalamus/hypothalamus (Th/HyT). Further scientific work is needed before using the results to decide on pathological changes in patients.

Miniaturized Endoscopic 2D US Transducer for Volumetric Ultrasound Imaging of the Auditory System.

In this paper, we focus on the carrying out and validation of minimally invasive three-dimensional (3D) ultrasound (US) imaging of the auditory system, which is based on a new miniaturized endoscopic 2D US transducer. This unique probe consists of a 18 MHz 24 elements curved array transducer with a distal diameter of 4 mm so it can be inserted into the external auditory canal. Typical acquisition is achieved by rotating such a transducer around its own axis using a robotic platform. Reconstruction of a US volume from the set of acquired B-scans during the rotation is then performed using scan-conversion. The accuracy of the reconstruction procedure is evaluated using a dedicated phantom that includes a set of wires as reference geometry. Twelve acquisitions obtained from different probe poses are compared to a micro-computed tomographic model of the phantom, leading to a maximum error of 0.20 mm. Additionally, acquisitions with a cadaveric head highlight the clinical applicability of this set up. Structures of the auditory system such as the ossicles and the round window can be identified from the obtained 3D volumes. These results confirm that our technique enables the accurate imaging of the middle and inner ears without having to deteriorate the surrounding bone. Since US is a real-time, wide available and non-ionizing imaging modality, our acquisition setup could facilitate the minimally invasive diagnosis and surgical navigation for otology in a fast, cost-effective and safe way.

Ultrasound Frame-to-Volume Registration via Deep Learning for Interventional Guidance.

Fusing intraoperative 2-D ultrasound (US) frames with preoperative 3-D magnetic resonance (MR) images for guiding interventions has become the clinical gold standard in image-guided prostate cancer biopsy. However, developing an automatic image registration system for this application is challenging because of the modality gap between US/MR and the dimensionality gap between 2-D/3-D data. To overcome these challenges, we propose a novel US frame-to-volume registration (FVReg) pipeline to bridge the dimensionality gap between 2-D US frames and 3-D US volume. The developed pipeline is implemented using deep neural networks, which are fully automatic without requiring external tracking devices. The framework consists of three major components, including one) a frame-to-frame registration network (Frame2Frame) that estimates the current frame's 3-D spatial position based on previous video context, two) a frame-to-slice correction network (Frame2Slice) adjusting the estimated frame position using the 3-D US volumetric information, and three) a similarity filtering (SF) mechanism selecting the frame with the highest image similarity with the query frame. We validated our method on a clinical dataset with 618 subjects and tested its potential on real-time 2-D-US to 3-D-MR fusion navigation tasks. The proposed FVReg achieved an average target navigation error of 1.93 mm at 5-14 fps. Our source code is publicly available at https://github.com/DIAL-RPI/Frame-to-Volume-Registration.

Automated estimation of mitral annular plane systolic excursion by artificial intelligence from 3D ultrasound recordings

Perioperative monitoring of cardiac function is beneficial for early detection of cardiovascular complications. The standard of care for cardiac monitoring performed by trained cardiologists and anesthesiologists involves a manual and qualitative evaluation of ultrasound imaging, which is a time-demanding and resource-intensive process with intraobserver- and interobserver variability. In practice, such measures can only be performed a limited number of times during the intervention. To overcome these difficulties, this study presents a robust method for automatic and quantitative monitoring of cardiac function based on 3D transesophageal echocardiography (TEE) B-mode ultrasound recordings of the left ventricle (LV). Such an assessment obtains consistent measurements and can produce a near real-time evaluation of ultrasound imagery. Hence, the presented method is time-saving and results in increased accessibility. The mitral annular plane systolic excursion (MAPSE), characterizing global LV function, is estimated by landmark detection and cardiac view classification of two-dimensional images extracted along the long-axis of the ultrasound volume. MAPSE estimation directly from 3D TEE recordings is beneficial since it removes the need for manual acquisition of cardiac views, hence decreasing the need for interference by physicians. Two convolutional neural networks (CNNs) were trained and tested on acquired ultrasound data of 107 patients, and MAPSE estimates were compared to clinically obtained references in a blinded study including 31 patients. The proposed method for automatic MAPSE estimation had low bias and low variability in comparison to clinical reference measures. The method accomplished a mean difference for MAPSE estimates of (−0.16±1.06) mm. Thus, the results did not show significant systematic errors. The obtained bias and variance of the method were comparable to inter-observer variability of clinically obtained MAPSE measures on 2D TTE echocardiography. The novel pipeline proposed in this study has the potential to enhance cardiac monitoring in perioperative- and intensive care settings.

Impact of Relative Volume Difference Between Magnetic Resonance Imaging and Three-dimensional Transrectal Ultrasound Segmentation on Clinically Significant Prostate Cancer Detection in Fusion Magnetic Resonance Imaging–targeted Biopsy

BackgroundSegmentation of three-dimensional (3D) transrectal ultrasound (TRUS) images is known to be challenging, and the clinician often lacks a reliable and easy-to-use indicator to assess its accuracy during the fusion magnetic resonance imaging (MRI)-targeted prostate biopsy procedure. ObjectiveTo assess the effect of the relative volume difference between 3D-TRUS and MRI segmentation on the outcome of a targeted biopsy. Design, setting, and participantsAll adult males who underwent an MRI-targeted prostate biopsy for clinically suspected prostate cancer between February 2012 and July 2021 were consecutively included. InterventionAll patients underwent a fusion MRI-targeted prostate biopsy with a Koelis device. Outcome measurements and statistical analysisThree-dimensional TRUS and MRI prostate volumes were calculated using 3D prostate models issued from the segmentations. The primary outcome was the relative segmentation volume difference (SVD) between transrectal ultrasound and MRI divided by the MRI volume (SVD = MRI volume − TRUS volume/MRI volume) and its correlation with clinically significant prostate cancer (eg, International Society of Urological Pathology [ISUP] ≥2) positiveness on targeted biopsy cores. Results and limitationsOverall, 1721 patients underwent a targeted biopsy resulting in a total of 5593 targeted cores. The median relative SVD was significantly lower in patients diagnosed with clinically significant prostate cancer than in those with ISUP 0–1: (6.7% [interquartile range {IQR} –2.7, 13.6] vs 8.0% [IQR 3.3, 16.4], p < 0.01). A multivariate regression analysis showed that a relative SVD of >10% of the MRI volume was associated with a lower detection rate of clinically significant prostate cancer (odds ratio = 0.74 [95% confidence interval: 0.55–0.98]; p = 0.038). ConclusionsA relative SVD of >10% of the MRI segmented volume was associated with a lower detection rate of clinically significant prostate cancer on targeted biopsy cores. The relative SVD can be used as a per-procedure quality indicator of 3D-TRUS segmentation. Patient summaryA discrepancy of ≥10% between segmented magnetic resonance imaging and transrectal ultrasound volume is associated with a reduced ability to detect significant prostate cancer on targeted biopsy cores.

On mimicking human’s manipulation for robot-assisted spine ultrasound imaging

Purpose This paper aims to develop a new robotic ultrasound system for spine imaging with more anthropomorphic scanning manipulation in comparison with previously reported techniques. Design/methodology/approach The system evaluates the imaging quality of ultrasound (US) B-scans by detecting vertebral landmarks and groups the images with relatively low quality into several sub-optimal types. By imitating the scanning skills of sonographers, the authors defined a set of adjustment strategies for certain sub-optimal types. In this way, the robot can recollect the US images with high quality by adaptively adjusting the pose of the probe like a sonographer. Findings The results from phantom experiments and in vivo experiments showed that the proposed method could improve the quality of B-scans during the scanning. The 3 D US volume reconstruction has also verified the feasibility of the proposed method. Originality/value This paper demonstrates how to adapt a robotic spinal ultrasound scanning using a preliminary anthropomorphic approach.

Three-dimensional ultrasound image reconstruction based on 3D-ResNet in the musculoskeletal system using a 1D probe: ex vivo and in vivo feasibility studies

Objective. Three-dimensional (3D) ultrasound (US) is needed to provide sonographers with a more intuitive panoramic view of the complex anatomical structure, especially the musculoskeletal system. In actual scanning, sonographers may perform fast scanning using a one-dimensional (1D) array probe .at random angles to gain rapid feedback, which leads to a large US image interval and missing regions in the reconstructed volume. Approach. In this study, a 3D residual network (3D-ResNet) modified by a 3D global residual branch (3D-GRB) and two 3D local residual branches (3D-LRBs) was proposed to retain detail and reconstruct high-quality 3D US volumes with high efficiency using only sparse two-dimensional (2D) US images. The feasibility and performance of the proposed algorithm were evaluated on ex vivo and in vivo sets. Main r esults. High-quality 3D US volumes in the fingers, radial and ulnar bones, and metacarpophalangeal joints were obtained by the 3D-ResNet, respectively. Their axial, coronal, and sagittal slices exhibited rich texture and speckle details. Compared with kernel regression, voxel nearest-neighborhood, squared distance weighted methods, and a 3D convolution neural network in the ablation study, the mean peak-signal-to-noise ratio and mean structure similarity of the 3D-ResNet were up to 28.53 ± 1.29 dB and 0.98 ± 0.01, respectively, and the corresponding mean absolute error dropped to 0.023 ± 0.003 with a better resolution gain of 1.22 ± 0.19 and shorter reconstruction time. Significance. These results illustrate that the proposed algorithm can rapidly reconstruct high-quality 3D US volumes in the musculoskeletal system in cases of a large amount of data loss. This suggests that the proposed algorithm has the potential to provide rapid feedback and precise analysis of stereoscopic details in complex and meticulous musculoskeletal system scanning with a less limited scanning speed and pose variations for the 1D array probe.

Weakly supervised learning-based 3D bladder reconstruction from 2D ultrasound images for bladder volume measurement.

Accurate measurement of bladder volume is necessary to maintain the consistency of the patient's anatomy in radiation therapy for pelvic tumors. As the diversity of the bladder shape, traditional methods for bladder volume measurement from 2D ultrasound have been found to produce inaccurate results. To improve the accuracy of bladder volume measurement from 2D ultrasound images for patients with pelvic tumors. The bladder ultrasound images from 130 patients with pelvic cancer were collected retrospectively. All data were split into a training set (80 patients), a validation set (20 patients), and a test set (30 patients). A total of 12 transabdominal ultrasound images for one patient were captured by automatically rotating the ultrasonic probe with an angle step of 15°. An incomplete 3D ultrasound volume was synthesized by arranging these 2D ultrasound images in 3D space according to the acquisition angles. With this as input, a weakly supervised learning-based 3D bladder reconstruction neural network model was built to predict the complete 3D bladder. The key point is that we designed a novel loss function, including the supervised loss of bladder segmentation in the ultrasound images at known angles and the compactness loss of the 3D bladder. Bladder volume was calculated by counting the number of voxels belonging to the 3D bladder. The dice similarity coefficient (DSC) was used to evaluate the accuracy of bladder segmentation, and the relative standard deviation (RSD) was used to evaluate the calculation accuracy of bladder volume with that of computed tomography (CT) images as the gold standard. The results showed that the mean DSC was up to 0.94 and the mean absolute RSD can be reduced to 6.3% when using 12 ultrasound images of one patient. Further, the mean DSC also was up to 0.90 and the mean absolute RSD can be reduced to 9.0% even if only two ultrasound images were used (i.e., the angle step is 90°). Compared with the commercial algorithm in bladder scanners, which has a mean absolute RSD of 13.6%, our proposed method showed a considerably huge improvement. The proposed weakly supervised learning-based 3D bladder reconstruction method can greatly improve the accuracy of bladder volume measurement. It has great potential to be used in bladder volume measurement devices in the future.

Three-dimensional endovaginal ultrasound assessment using the levator ani deficiency score in primiparas: A replication study.

It is essential to assess the levator ani properly as part of clinical care in patients presenting with pelvic floor dysfunction. The levator ani deficiency scoring system is a previously published method to assess levator ani defects with three-dimensional endovaginal ultrasound. The primary aim of this study was to determine the intra- and interrater reliability of the levator ani deficiency score in a cohort of non-instrumentally delivered primiparas. Primiparas (n = 141) were examined at least 1 year after vaginal birth. Three-dimensional endovaginal ultrasound volumes were acquired by a single examiner using two different automated ultrasound probes. The volumes were analyzed by two separate raters who were blinded to each other's assessments. Descriptive statistics were calculated for levator ani deficiency score and categorized into three levels (mild, moderate, severe). Kendall's tau-b was calculated for intra- and interrater comparisons. Intrarater comparisons of levator ani deficiency score and levator ani deficiency category were high (Kendall's tau-b ≥0.80 for Rater 1; >0.79 for Rater 2). Interrater comparisons of levator ani deficiency score and levator ani deficiency category were also high (Kendall's tau-b >0.9 for assessment 1 and >0.78 for assessment 2). Varying by rater, probe and assessment, 75.9%-80.1% of the study population had no/mild deficiency, 6.4%-9.2% had moderate deficiency, and 4.3%-6.4% had severe levator ani deficiency. The levator ani deficiency scoring system is a feasible method to assess defects of the levator ani muscle and can be reproduced with high intra- and interrater correlations. Using the scoring system in clinical practice may facilitate concordant assessment between different examiners. However, the system should be used to support clinical findings and symptomatology and not as a screening tool, as the score is lacking the category of no levator ani deficiency.

Sonographic assessment of Prostate and Post void Residual Urine Volumes in patients with benign prostatic hypertrophy in Makurdi, North-central Nigeria

Background: Benign prostatic hypertrophy (BPH) is a major global public health problem and the most common benign prostatic disease in elderly men. Although rarely life-threatening, the increased morbidity significantly lowers men's quality of life, necessitating significant financial commitment to their annual health budgetary expenditure. We aim at determining the sonographic volumes of the prostate and post void residual urine in adult Nigerian men with BPH in Makurdi and to document any relevant relationship between the two values. Materials and methods: This was a 10-month prospective cross-sectional study conducted from June 2021 to April 2022. Transabdominal ultrasound (TAUS) was used to measure the prostate and post-void residual urine volumes of 78 men aged 40years and older, with normal levels of prostatic-specific antigen (PSA), who were referred to the ultrasound unit of radiology department of Benue State University Teaching Hospital (BSUTH), Makurdi. Collected data were analyzed using SPSS and Microsoft excel with P&lt;0.05. Results: Postvoid residual urine volume (PVR) was observed to increase alongside the prostate volume (PV) from the 5th to the 6th decade of life; however, PVR began fluctuating from the 7th to the 8th decade, even though PV continued to increase steadily to its peak value at the 70-79 years of age, or the 8th decade. Overall, the mean prostate and post void residual urine volumes were 64.07±37.00ml and 76.44±110.34ml, respectively. A statistically significant (P=0.017) relationship existed between age and prostate volume but not between PV and PVR (P=0.128), where there was instead a weak, positive correlation. Although the bladder wall thickness (BWT) was greater than 5mm in more than half of the respondents 43(55.10%), there was no statistically significant (P=0.130) relationship between age and BWT. Conclusion: We established 64.07±37.00ml and 76.44±110.34ml respectively, as the overall mean sonographic volumes of the prostate and post void residual urine in adult Nigerian men with BPH in Makurdi. Despite the weak correlation between the two volumes, they can be used as a baseline for monitoring the progression of prostatic hyperplasia, bladder outlet obstruction and deciding on the best treatment option.

Validation of an automatic software in assessing fetal brain volume from three dimensional ultrasonographic volumes: Comparison with manual analysis.

This study was aimed to test the agreement between a manual and an automatic technique in measuring fetal brain volume (FBV) from three-dimensional (3D) fetal head datasets. FBV were acquired independently by two operators from low risk singleton pregnancies at a gestational age between 19 and 34 weeks. FBV measurements were obtained using an automatic software (Smart ICV™) and manually by Virtual Organ Computer-aided AnaLysis (VOCAL™). Intraclass correlation coefficient (ICC) were calculated to assess reliability, while bias and agreement were evaluate by examining Bland-Altman plots. The time spent in measuring volumes was calculated and values obtained compared. Sixty-three volumes were considered for the study. In all the included volumes successful volume analysis were obtained with both techniques. Smart ICV™ showed a high intra-observer (0.996; 95% CI 0.994-0.998) and inter-observer (ICC 0.995; 95% CI 0.991-0.997). An excellent degree of reliability was found when the two techniques were compared (ICC 0.995; 95% CI 0.987-0.998). The time required to perform FBV was significantly lower for Smart ICV™ than VOCAL™ (8.2 ± 4.5 vs. 121.3 ± 19.0 s; p < 0.0001). The measurement of FBV is feasible with both manual and automatic techniques. Smart ICV™ showed an excellent intra- and inter-observer reliability associated with a valuable agreement with volume measurements obtained manually with VOCAL™. Volumes may be measured significantly faster with smart ICV™ than manually and this automatic software has the potential to become the preferred methods for the assessment of FBV.

Comparison of image quality of 3D ultrasound: motorized acquisition versus freehand navigated acquisition, a phantom study

PurposeIntra-operative assessment of resection margins during oncological surgery is a field that needs improvement. Ultrasound (US) shows the potential to fulfill this need, but this imaging technique is highly operator-dependent. A 3D US image of the whole specimen may remedy the operator dependence. This study aims to compare and evaluate the image quality of 3D US between freehand acquisition (FA) and motorized acquisition (MA).MethodsMultiple 3D US volumes of a commercial phantom were acquired in motorized and freehand fashion. FA images were collected with electromagnetic navigation. An integrated algorithm reconstructed the FA images. MA images were stacked into a 3D volume. The image quality is evaluated following the metrics: contrast resolution, axial and elevation resolution, axial and elevation distance calibration, stability, inter-operator variability, and intra-operator variability. A linear mixed model determined statistical differences between FA and MA for these metrics.ResultsThe MA results in a statistically significant lower error of axial distance calibration (p < 0.0001) and higher stability (p < 0.0001) than FA. On the other hand, the FA has a better elevation resolution (p < 0.003) than the MA.ConclusionMA results in better image quality of 3D US than the FA method based on axial distance calibration, stability, and variability. This study suggests acquiring 3D US volumes for intra-operative ex vivo margin assessment in a motorized fashion.

Diagnosis of fetal cortical abnormalities by new reference charts for assessment of sylvian fissure biometry.

To develop novel fetal reference ranges for the characterization of the normal appearance of the Sylvian fissures (SF) along gestation and to apply them to fetuses with cortical abnormalities affecting the SF. In this cross-sectional study, we used three-dimensional sonographic multiplanar reformatting (3D-MPR) to examine the fetal SF. Normal development was assessed in the second and third trimesters. SF parameters were evaluated in predefined axial and coronal planes: insular height and length, SF depth, and the extent of the coverage of the insula by the frontal and temporal lobes. Intra-observer variability and inter-rater reliability for the studied parameters were evaluated. The new reference charts were applied to 19 fetuses with cortical abnormalities involving the SF who had appropriate sonographic volumes for 3D-MPR analysis. Their diagnoses were confirmed by autopsy, fetal or postnatal MRI, genetic findings related to cortical malformations, or an abnormal cortical imaging pattern with similar MRI findings in an affected sibling. We applied the two previously published references for the evaluation of fetal SF development to these cases and compared the ability of the references to correctly detect SF abnormalities. The study included 189 fetuses of low-risk singleton pregnancies between 24 and 34 gestational weeks. The insular length or height increased with gestational age in the axial and coronal planes with adjusted R2 =0.621, p<0.0001 and R2 =0.384, p<0.0001, respectively. The SF depth also increased with gestational age in the axial and coronal planes with adjusted R2 =0.695, p<0.0001 and R2 =0.219, p=0.008, respectively. The extent of the coverage of the insula by the frontal and temporal lobes in the coronal plane increased with gestational age (adjusted R2 =0.627, p<0.0001 and R2 =0.589, p<0.0001, respectively). The interclass correlation coefficients of the intra- and inter-rater reliability of the studied parameters ranged between 0.71 and 0.97. The cortical anomalies in the 19 fetuses were polymicrogyria (7), simplified gyral pattern (3), dysgyria (3), lissencephaly (2), cortical malformation related to tubulinopathy (1), brain atrophy (1), cortical dysplasia (1), and cobblestone malformation (1). Three of the fetuses had multiple cortical anomalies. In 17 of 19 (89%) cases, at least one of our 6 SF parameters was found to be out of the normal range. In the coronal plane, SF height and depth were measured below 2SD in 9 (47%) and 4 (21%) cases, respectively. In the axial plane, SF length and depth were out of the normal ranges in six (31.5%) and four (21%), correspondingly. In the coronal plane, the opercular coverage by the frontal and temporal lobes was below 2 SD in 10 (52%) and 11 (57%), respectively. The scoring of the SF operculization by Quarello etal. was abnormal in 8 cases (42%). The measurement of the SF angle according to Poon etal. was abnormal in 14 cases (74%). The fetal SF is a complex developing structure that can be reliably characterized by sonographic parameters. One abnormal parameter is sufficient to raise the suspicion of SF malformation. Our new SF parameters might facilitate the detection of prenatal cortical abnormalities affecting the SF.

A Lightweight Deep Learning Network on a System-on-Chip for Wearable Ultrasound Bladder Volume Measurement Systems: Preliminary Study.

Bladder volume assessments are crucial for managing urinary disorders. Ultrasound imaging (US) is a preferred noninvasive, cost-effective imaging modality for bladder observation and volume measurements. However, the high operator dependency of US is a major challenge due to the difficulty in evaluating ultrasound images without professional expertise. To address this issue, image-based automatic bladder volume estimation methods have been introduced, but most conventional methods require high-complexity computing resources that are not available in point-of-care (POC) settings. Therefore, in this study, a deep learning-based bladder volume measurement system was developed for POC settings using a lightweight convolutional neural network (CNN)-based segmentation model, which was optimized on a low-resource system-on-chip (SoC) to detect and segment the bladder region in ultrasound images in real time. The proposed model achieved high accuracy and robustness and can be executed on the low-resource SoC at 7.93 frames per second, which is 13.44 times faster than the frame rate of a conventional network with negligible accuracy drawbacks (0.004 of the Dice coefficient). The feasibility of the developed lightweight deep learning network was demonstrated using tissue-mimicking phantoms.

Medical management of retained products of conception: A prospective observational study

Objective(s)To measure the success rate of primary medical therapy in managing retained products of conception (RPOC) in women with secondary postpartum haemorrhage (PPH) and to identify factors associated with need for surgical management. Study designPostpartum patients presenting to a tertiary women’s hospital Emergency Department between July 2020 and December 2022 with secondary PPH and evidence of RPOC on ultrasound were recruited. Clinical information relating to the presentation was collected prospectively. Antenatal and intrapartum data were collected from medical record and Birthing Outcome System database review. The primary outcome was the success of medical management for RPOC, defined by the implementation of medical or expectant management without subsequent need for surgical intervention. ResultsForty-one patients with RPOC underwent primary medical or expectant management. Twelve patients (29%) were managed successfully with medical management, while twenty-nine (71%) proceeded to surgical management. Medical management involved antibiotics (n = 37, 90%), prostaglandin E1 analogue (n = 14, 34%) and other uterotonics (n = 3, 7%). A greater endometrial thickness on ultrasound was significantly associated with a requirement for secondary surgical intervention (p < 0.05). There was an association approaching statistical significance between a higher sonographic volume of RPOC and the failure of medical management (p = 0.07). There was no statistically significant association between the mode of delivery or the number of days postpartum with the success of medical management. Conclusion(s)For patients presenting with secondary PPH and sonographic RPOC, over two thirds required surgical management. Increased endometrial thickness was associated with an increased requirement for surgical management.

Automated segmentation and measurement of the female pelvic floor from the mid-sagittal plane of 3D ultrasound volumes.

Transperineal ultrasound (TPUS) is a valuable imaging tool for evaluating patients with pelvic floor disorders, including pelvic organ prolapse (POP). Currently, measurements of anatomical structures in the mid-sagittal plane of 2D and 3D US volumes are obtained manually, which is time-consuming, has high intra-rater variability, and requires an expert in pelvic floor US interpretation. Manual segmentation and biometric measurement can take 15 min per 2D mid-sagittal image by an expert operator. An automated segmentation method would provide quantitative data relevant to pelvic floor disorders and improve the efficiency and reproducibility of segmentation-based biometric methods. Develop a fast, reproducible, and automated method of acquiring biometric measurements and organ segmentations from the mid-sagittal plane of female 3D TPUS volumes. Our method used a nnU-Net segmentation model to segment the pubis symphysis, urethra, bladder, rectum, rectal ampulla, and anorectal angle in the mid-sagittal plane of female 3D TPUS volumes. We developed an algorithm to extract relevant biometrics from the segmentations. Our dataset included 248 3D TPUS volumes, 126/122 rest/Valsalva split, from 135 patients. System performance was assessed by comparing the automated results with manual ground truth data using the Dice similarity coefficient (DSC) and average absolute difference (AD). Intra-class correlation coefficient (ICC) and time difference were used to compare reproducibility and efficiency between manual and automated methods respectively. High ICC, low AD and reduction in time indicated an accurate and reliable automated system, making TPUS an efficient alternative for POP assessment. Paired t-test and non-parametric Wilcoxon signed-rank test were conducted, with p<0.05 determining significance. The nnU-Net segmentation model reported average DSC and p values (in brackets), compared to the next best tested model, of 87.4% (<0.0001), 68.5% (<0.0001), 61.0% (0.1), 54.6% (0.04), 49.2% (<0.0001) and 33.7% (0.02) for bladder, rectum, urethra, pubic symphysis, anorectal angle, and rectal ampulla respectively. The average ADs for the bladder neck position, bladder descent, rectal ampulla descent and retrovesical angle were 3.2mm, 4.5mm, 5.3mm and 27.3°, respectively. The biometric algorithm had an ICC>0.80 for the bladder neck position, bladder descent and rectal ampulla descent when compared to manual measurements, indicating high reproducibility. The proposed algorithms required approximately 1.27 s to analyze one image. The manual ground truths were performed by a single expert operator. In addition, due to high operator dependency for TPUS image collection, we would need to pursue further studies with images collected from multiple operators. Based on our search in scientific databases (i.e., Web of Science, IEEE Xplore Digital Library, Elsevier ScienceDirect and PubMed), this is the first reported work of an automated segmentation and biometric measurement system for the mid-sagittal plane of 3D TPUS volumes. The proposed algorithm pipeline can improve the efficiency (1.27 s compared to 15 min manually) and has high reproducibility (high ICC values) compared to manual TPUS analysis for pelvic floor disorder diagnosis. Further studies are needed to verify this system's viability using multiple TPUS operators and multiple experts for performing manual segmentation and extracting biometrics from the images.

Robotically controlled three-dimensional micro-ultrasound for prostate biopsy guidance.

Prostate imaging to guide biopsy remains unsatisfactory, with current solutions suffering from high complexity and poor accuracy and reliability. One novel entrant into this field is micro-ultrasound (microUS), which uses a high-frequency imaging probe to achieve very high spatial resolution, and achieves prostate cancer detection rates equivalent to multiparametric magnetic resonance imaging (mpMRI). However, the ExactVu transrectal microUS probe has a unique geometry that makes it challenging to acquire controlled, repeatable three-dimensional (3D) transrectal ultrasound (TRUS) volumes. We describe the design, fabrication, and validation of a 3D acquisition system that allows for the accurate use of the ExactVu microUS device for volumetric prostate imaging. The design uses a motorized, computer-controlled brachytherapy stepper to rotate the ExactVu transducer about its axis. We perform geometric validation using a phantom with known dimensions and compare performance with magnetic resonance imaging (MRI) using a commercial quality assurance anthropomorphic prostate phantom. Our geometric validation shows accuracy of 1mm or less in all three directions, and images of an anthropomorphic phantom qualitatively match those acquired using MRI and show good agreement quantitatively. We describe the first system to acquire robotically controlled 3D microUS images using the ExactVu microUS system. The reconstructed 3D microUS images are accurate, which will allow for future applications of the ExactVu microUS system in prostate specimen and in vivo imaging.