Dynamic and static nasolabial muscle anatomy of unilateral cleft lip adult patients based on magnetic resonance imaging data.

OBJECTIVES: This study aims to obtain a three-dimensional reconstruction model based on magnetic resonance imaging (MRI) data of patients with different degrees of unilateral cleft lip and analyze the anatomy and changes in multiple groups of nasolabial muscles under dynamic and static conditions. METHODS: One normal person and four adult patients with unilateral cleft lip were included, and MRI was performed under static (upper and lower lips closed naturally) and dynamic (pout and grin) conditions. 3D Slicer software was used to reconstruct the model and draw the anatomic morphology of nasolabial muscles. The distance between the junction (where the muscle merges into the orbicularis oris) of the levator muscle, zygomaticminor muscle, and zygomatic major muscle to the median sagittal plane, the starting point to the junction point, the dynamic and static junction points, and the angle between the connection of dynamic and static junctions and the horizontal plane were measured under three kinds of movements, and the ratio was calculated. RESULTS: In all patients, under dynamic and static conditions, the distance from the muscle junction to the median sagittal plane, their ratios of the cleft side to the non-cleft side were all greater than 1. While the ratio of the distance from the starting point of the muscle to the junction point is less than 1. At static conditions, the two ratios of the same muscle increased gradiently with the severity of the cleft, and the ratio of the zygomatic minor muscle was prominent in the same patient. The ratio of the cleft side to the non-cleft side was greater than 1, and the value for comparison was the angle of the line from the static to the dynamic junction and the horizontal plane. CONCLUSIONS: The symmetry of the insertion site of the orbicularis oris and the linear distance of both sides of the muscle are related to muscle and cleft types. The angle of muscle contraction on the cleft side is greater than that on the non-cleft side.

[Forensic imaging of sharp force injuries]. / Forensische Bildgebung der scharfen Gewalt.

BACKGROUND: Answering legal questions is everyday routine in forensic medicine. The reconstruction of violent crimes following attacks with sharp and/or pointed instruments is usually complex and can hardly be adequately answered using traditional forensic methods such as autopsies. For this reason, clinical and postmortem radiology has become the ideal complement to forensic medicine. METHODS: While classic X­ray is unsuitable to image soft tissue injuries, and magnetic resonance imaging is too expensive, too complex and also not available everywhere, multislice computed tomography (MSCT) has now emerged as the method of choice in forensic imaging for the assessment of the consequences of sharp force injuries. ACHIEVEMENTS: Forensic imaging, especially MSCT, offers an indispensable addition to reconstruction, particularly after stab wounds. In many cases, it is at least equal to, and in some cases superior to, the classic autopsy in the assessment of stab wounds, the reconstruction of the sequence of events or the assessment of (life-threatening) injuries. CONCLUSIONS: The forensic radiological assessment after sharp violence requires experience in both the field of radiology and forensic medicine. Provided that both disciplines work closely together, forensic radiology can be an essential tool in the care for victims of violence.

Chloroplasts with clefts and holes: a reassessment of the chloroplast shape using 3D FE-SEM cellular reconstruction of two species of Chlamydomonas.

Chloroplasts are usually considered spheroid organelles, but this is not the only shape of chloroplasts. The chloroplast of Chlamydomonas has been typically described as cup-shaped. However, in old studies, it was also modeled as a complex shape with "perforations" or windows. Here, we reconstructed the cellular architecture of Chlamydomonas reinhardtii and C. applanata using an array tomography system installed on a field emission scanning electron microscope. C. reinhardtii chloroplasts resembled a baseball glove or a cup without a side, featuring numerous large and small holes that may facilitate the transport of metabolites and proteins produced in the Golgi apparatus fitted in the holes. In a lipid-accumulating, high-light condition, the chloroplast volume increased by filling the side cleft with an entire wall. Many accumulated large lipid droplets were accommodated within the chloroplast holes, which could have been considered as "chloroplast lipid droplets." Mitochondrial meshworks surrounded the chloroplast. C. applanata chloroplasts appeared like a folded starfish or a cup with many side clefts and a few holes. There was a single mitochondrion or two that branched in a complex form. Tight contacts of various organelles were also found in C. applanata. These reconstructions illustrate the complexity of chloroplast shape, which necessitates a revised understanding of the localization of lipid droplets and the evolution of chloroplasts: The prevailing image of the spheroid chloroplasts that reminds us of the similarity between chloroplasts and cyanobacteria is no longer tenable.

Geometric consistency among atherosclerotic plaques in carotid arteries evaluated by multidimensional parameters.

The three-dimensional (3D) geometry of carotid atherosclerotic plaques is associated with multiple cardiovascular diseases. However, it is unknown if carotid plaques of different sizes are consistent in 3D geometry, with a lack of quantitative observation. We aim to evaluate the geometric consistency of carotid plaques using the correlations between multidimensional parameters. 42 cases with asymptomatic stenosis caused by atherosclerotic plaque in the carotid artery were included. Carotid plaques and calcifications were identified on computed tomography angiography images and 3D reconstructed. Multidimensional geometric parameters (length, surface area, volume, etc.) were measured on the reconstructed 3D structures. Linear and non-linear (power function) fittings were used to investigate the relationships between multidimensional parameters. The analysis was performed based on cases and plaques, respectively. Spearman rank correlation analysis, R-squared, and p-values were used to evaluate the significance of the relationship. Significant relationship was defined as R-squared >0.25 and p < 0.05. In total, 112 atherosclerotic plaques and 74 calcifications were extracted. In plaque-based analysis, significant correlations were widely observed between paired multidimensional parameters of carotid plaques, where non-linear fitting showed higher R-squared values. Plaque volume and surface area were significantly correlated with total volume and total surface area of intra-plaque calcifications. In subject-based analysis, triglycerides and total cholesterol were significantly correlated with carotid plaque size. There is a consistency in geometry among carotid atherosclerotic plaques of different sizes. The size of a carotid plaque is associated with the patient's lipid profile.

Monocular visual SLAM, visual odometry, and structure from motion methods applied to 3D reconstruction: A comprehensive survey.

Monocular Simultaneous Localization and Mapping (SLAM), Visual Odometry (VO), and Structure from Motion (SFM) are techniques that have emerged recently to address the problem of reconstructing objects or environments using monocular cameras. Monocular pure visual techniques have become attractive solutions for 3D reconstruction tasks due to their affordability, lightweight, easy deployment, good outdoor performance, and availability in most handheld devices without requiring additional input devices. In this work, we comprehensively overview the SLAM, VO, and SFM solutions for the 3D reconstruction problem that uses a monocular RGB camera as the only source of information to gather basic knowledge of this ill-posed problem and classify the existing techniques following a taxonomy. To achieve this goal, we extended the existing taxonomy to cover all the current classifications in the literature, comprising classic, machine learning, direct, indirect, dense, and sparse methods. We performed a detailed overview of 42 methods, considering 18 classic and 24 machine learning methods according to the ten categories defined in our extended taxonomy, comprehensively systematizing their algorithms and providing their basic formulations. Relevant information about each algorithm was summarized in nine criteria for classic methods and eleven criteria for machine learning methods to provide the reader with decision components to implement, select or design a 3D reconstruction system. Finally, an analysis of the temporal evolution of each category was performed, which determined that the classical-sparse-indirect and classical-dense-indirect categories have been the most accepted solutions to the monocular 3D reconstruction problem over the last 18 years.

How to Set Working Cannula in Endoscopic-Assisted Transforaminal Lumbar Interbody Fusion: A Morphometric Analysis Based on Computed Tomography.

OBJECTIVES: There is a high risk of nerve root injury during endoscopic-assisted transforaminal lumbar interbody fusion (Endo-TLIF). This study used computed tomography (CT) imaging to assess the relationship between the exiting nerve root and its surroundings, and the corresponding intervertebral disc. We also measured the approximate position and angle for the placement of the working cannula to reduce the risk of nerve root injury during Endo-TLIF procedures in the Chinese population. METHODS: This retrospective study was conducted at our institution between December 2021 and December 2022. A total of 115 patients suffering from low back pain were recruited for the study. For each participant, three-dimensional (3D) vertebral models of the lumbar segments from L3 to S1 were constructed based on their CT images. The nerve root-disc distance, cannula insertion bypass distance and angle, foraminal height and width, exiting nerve root height, and nerve root-pedicle distance were measured. A paired t-test was used to compare measurements between the left and right sides, while inter- and intraobserver reproducibility was assessed using the intraclass correlation coefficient (ICC). RESULTS: From L3/4 to L5/S1 segments, the ideal cannula insertion distance range was 37.51 ± 4.91-120.38 ± 37.71 mm at L3/4; 42.38 ± 5.29-116.25 ± 27.22 mm at L4/5; and 37.78 ± 4.86-69.26 ± 12.64 mm at L5/S1. The appropriate cannula insertion angle range was 30.86° ± 5.05°-62.59° ± 6.66° at L3/4; 34.30° ± 4.73°-60.88° ± 7.34° at L4/5; and 35.89° ± 4.18°-47.65° ± 7.38° at L5/S1. The height of the intervertebral foramen (IVF) gradually decreased, and the width steadily increased. The exiting nerve root height and the nerve root-pedicle distance slightly decreased caudally. CONCLUSION: From L3/4 to L5/S1, the range of working cannula insertion distance and angle gradually decreased, and the exiting nerve root height occupying the IVF gradually increased. Our measurement can reduce the risk of nerve root injury caused by inserting the working cannula during Endo-TLIF.

Application value of multi-parameter magnetic resonance image-transrectal ultrasound cognitive fusion in prostate biopsy.

Objective: To investigate the effect of three-dimensional (3D) reconstruction-assisted cognitive fusion in targeted prostate biopsy. Results: There was no significant difference in the detection rate of prostate cancer (PCa) between targeted biopsy and systematic biopsy, and there was significant difference in the detection rate of clinically significant prostate cancer (csPCa) between targeted biopsy and systematic biopsy. In the low prostate total specific antigen (tPSA) group, there was no statistically significant difference in the detection rate of prostate cancer between the two biopsy modalities. However, compared with systematic puncture, targeted puncture had a higher detection rate for csPCa and a lower detection rate for clinically insignificant prostate cancer (ciPCa), and the difference was statistically significant. In the high tPSA group, there was no significant difference in the detection rate of PCa, csPCa, and ciPCa between the two biopsy types. Single needle positive rate of targeted puncture (29.77%) was significantly higher than that of systematic puncture (10.28%). Conclusions: The detection rate of csPCa in 3D reconstruction-assisted cognitive fusion targeted prostate biopsy is better than that of 12-needle systematic biopsy, which markedly improved the positive rate of prostate biopsy.

The relationship between humeral head angulation and bone void within the humeral head in proximal humerus fractures.

Background: The variability of humeral head angulation in proximal humerus fractures (PHFs) is a noteworthy observation. The purpose of this study was to investigate the potential association between humeral head angulation and bone void within the humeral head in PHFs. Methods: We used the reconstruction function in Mimics software to generate three-dimensional models of fractures. Bony landmarks were employed to accurately define the calcar and humeral head zone. Boolean subtraction was performed to calculate the volume of head bone void. Results: The cohort consisted of 60 (74.1 %) varus, 21 (25.9 %) valgus, and 23 (22.1 %) neutral angulated PHFs. The mean percentage of humeral head bone void was 38.5 ± 17.8 in varus, 36.3 ± 15.7 in valgus, and 30.1 ± 10.6 in neutral angulated PHFs. A significant difference was observed between the varus and neutral groups (P = 0.035). In addition, an analysis of humeral head bone void was conducted among patients aged over 65 years old, revealing a mean percentage of 42.7 ± 16.4 in varus (27 cases), 34.8 ± 14.5 in valgus (13 cases), and 28.1 ± 11.8 in neutral (8 cases) angulated PHFs. The difference between the varus and neutral groups was also significant (P = 0.023). Conclusion: All types of angulation patterns exhibited humeral head bone void to some extent, with the varus-displaced PHFs demonstrating more obvious defects in comparison to the neutral angulated type.

Three-dimensional reconstruction of rat sperm using volume electron microscopy.

Three-dimensional (3D) reconstruction serves as a crucial instrument for the analysis of biological structures. In particular, a comprehensive and accurate 3D ultrastructural examination of rat sperm is vital for understanding and diagnosing male fertility issues and the underlying causes of infertility. In this study, we utilize the automated tape-collecting ultramicrotome scanning electron microscopy (ATUM-SEM) imaging technique, which is a highly effective method for 3D cellular ultrastructural analysis. Our findings reveal that during spermiogenesis, the volume of the nucleus significantly decreases, shrinking to just 10% of its original size. The acrosomal vesicles derived from the Golgi apparatus converge and elongate along the spermatid nucleus. These vesicles then attach to the nucleus via a cap-like structure, thereby defining the head side of the spermatozoa. In the initial stages of spermiogenesis, the mitochondria in spermatids are distributed beneath the cell membrane. As the process progresses, these mitochondria gradually migrate to the sperm tail, where they form the mitochondrial sheath. This sheath plays a crucial role in providing the energy required for the movement of the sperm. In addition, we reconstruct the mRNA-stroring structure-chromatoid body in sperm cells, which are cloud-like or net-like structures in the cytoplasm. The precise and comprehensive nature of 3D ultrastructural examination allows for a deeper understanding of the morphological process of spermiogenesis, thereby contributing to our knowledge of male fertility and the causes of infertility. Our research has significantly advanced the understanding of the 3D ultrastructure of sperm more comprehensively than ever before.

A review: artificial intelligence in image-guided spinal surgery.

INTRODUCTION: Due to the complex anatomy of the spine and the intricate surgical procedures involved, spinal surgery demands a high level of technical expertise from surgeons. The clinical application of image-guided spinal surgery has significantly enhanced lesion visualization, reduced operation time, and improved surgical outcomes. AREAS COVERED: This article reviews the latest advancements in deep learning and artificial intelligence in image-guided spinal surgery, aiming to provide references and guidance for surgeons, engineers, and researchers involved in this field. EXPERT OPINION: Our analysis indicates that image-guided spinal surgery, augmented by artificial intelligence, outperforms traditional spinal surgery techniques. Moving forward, it is imperative to collect a more expansive dataset to further ensure the procedural safety of such surgeries. These insights carry significant implications for the integration of artificial intelligence in the medical field, ultimately poised to enhance the proficiency of surgeons and improve surgical outcomes.

Clinical observation of three-dimensional reconstruction in thoracoscopic segmental pneumonectomy.

BACKGROUND: Accurately identifying the branches of pulmonary segmental vessels and bronchi, as well as adjacent structures, and determining the spatial location of lesions within pulmonary segments, are major challenges for thoracic surgeons. The application of three-dimensional reconstruction technology holds promise in addressing this issue. OBJECTIVE: To evaluate the clinical value of three-dimensional reconstruction in thoracoscopic segmental surgery. METHODS: Seventy-seven patients who underwent thoracoscopic segmental surgery combined with three-dimensional reconstruction at our hospital from January 1, 2020, to August 31, 2023, were retrospectively analyzed. Preoperative chest enhanced CT scans were conducted, and MIMICS software aided in reconstructing DICOM format original data for patients with pulmonary nodules to facilitate intraoperative nodule localization. Accurate segmental pneumonectomy was performed by comparing preoperative anatomical identification of target segmental arteries, veins, and bronchi, with surgical details and postoperative outcomes recorded, including intraoperative pulmonary resection distribution, operation time, blood loss, chest tube drainage, extubation time, hospital stay, and complications. RESULTS: Following preoperative three-dimensional reconstruction, successful segmental lung surgeries were performed, predominantly with single segmental resection (92.2%), and a minority with combined segmentectomy (7.8%). Median operation time was 130225 minutes, with intraoperative blood loss at 70100 mL and postoperative chest tube drainage at 347 mL (159690 mL). Median extubation time and hospital stay were 4 days and 7 days, respectively. Complications within the 3-month follow-up affected 11.7% of cases, including persistent pulmonary leakage (7.1%), pulmonary infection (4.3%), atelectasis (4.3%), and pleural effusion (1.4%), with no fatalities. CONCLUSION: Preoperative 3D reconstruction can help the operator to perform safe, efficient and accurate thoracoscopic segmental pneumonectomy, which is worth popularizing in clinic.

High-frequency ultrasound-assisted Mohs micrographic surgery for the treatment of dermatofibrosarcoma protuberans.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a superficial sarcoma characterized by infiltrative growth with tentacle-like borders. Mohs micrographic surgery (MMS) is the preferred treatment option for DFSP. However, the imprecise boundary localization in MMS leads to an increased number of Mohs layers required and a longer surgery time. High-frequency ultrasound has excellent tissue recognition capability for DFSP, allowing for precise boundary marking. MATERIALS AND METHODS: In this study, we retrospectively analyzed 14 cases of DFSP treated with MMS using preoperative ultrasound localization and three-dimensional reconstruction at Xiangya Hospital over the past 5 years. We also reviewed previous studies on MMS for DFSP treatment. RESULTS: It was found that the average number of Mohs layers for patients after preoperative ultrasound localization was 1.57, ranging from 1 to 3, which was less than the previously reported 1.86 layers, ranging from 1 to 12. This effectively reduced the number of Mohs layers required. CONCLUSIONS: By utilizing preoperative high-frequency ultrasound to determine the boundaries and depth of DFSP, the number of Mohs layers can be effectively reduced, leading to less workload for pathological examination, shorter operation time, and reduced surgical risks for patients. Ultrasound imaging data can be used for three-dimensional reconstruction, enabling less experienced Mohs surgeons to have a visual understanding of the morphology and extent of infiltration of the lesions. This aids in developing optimal surgical plans, smoothing the learning curve, and promoting the wider adoption of MMS.

A Transparent Soil Experiment to Investigate the Influence of Arrangement and Connecting Beams on the Pile-Soil Interaction of Micropile Groups.

The use of a micropile group is an effective method for small and medium-sized slope management. However, there is limited research on the pile-soil interaction mechanism of micropile groups. Based on transparent soil and PIV technology, a test platform for the lateral load testing of slopes was constructed, and eight groups of transparent soil slope model experiments were performed. The changes in soil pressure and pile top displacement at the top of the piles during lateral loading were obtained. We scanned and photographed the slope, and obtained the deformation characteristics of the soil interior based on particle image velocimetry. A three-dimensional reconstruction program was developed to generate the displacement isosurface behind the pile. The impacts of various arrangement patterns and connecting beams on the deformation attributes and pile-soil interaction mechanism were explored, and the pile-soil interaction model of group piles was summarized. The results show that the front piles in a staggered arrangement bore more lateral thrust, and the distribution of soil pressure on each row of piles was more uniform. The connecting beams enhanced the overall stiffness of the pile group, reduced pile displacement, facilitated coordinated deformation of the pile group, and enhanced the anti-sliding effect of the pile-soil composite structure.

The analysis of different types of anorectal abscesses was conducted using the MRI 3D reconstruction technique.

It has not yet been proven whether sepsis affects the tissue around the anal canal. To address this issue, we established three-dimensional models for various types of anorectal abscesses and utilize 3D reconstruction of Magnetic Resonance Imaging scans to assess the extent of muscle damage caused by anorectal abscesses. Patients diagnosed with anorectal abscess, selected from January 2019 to January 2022 underwent pre- and post-operative scanning of pelvic floor and perianal tissues. The aforementioned structures were segmented for the reconstruction of a three-dimensional visual model and measurement of volumes for the abscess as well as the internal and external sphincters and levator ani muscle. The study included a total of 42 patients. Three-dimensional visualization models were created for different types of anorectal abscesses, including perianal, intersphincteric, ischiorectal, and supralevator abscesses. No statistically significant differences were observed in the volume of the internal sphincter, external sphincter, and levator ani muscle between pre- and post-operative patients. The 3D model of anorectal abscess, reconstructed from MRI data, offers a precise and direct visualization of the anatomical structures associated with various types of anorectal abscesses. The infection did not result in any damage to the internal and external anal sphincter and levator ani muscle.

Evaluating three-dimensional lung reconstructions for thoracoscopic lung resections using open-source software: a pilot study.

Background: Preoperative three-dimensional (3D) lung reconstructions can reduce intraoperative blood loss, conversion rate, and operation duration. These 3D reconstructions are predominantly provided by commercial expensive products, hence we aimed to assess the usability and performance of preoperative 3D lung reconstructions created with open-source software. Methods: Patients were invited to participate in this prospective pilot study if they were planned for uniportal video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy between January and February 2023. Participants were excluded if a two-dimensional (2D) late-arterial-phase computed tomography (CT) scan contained motion artifacts, another surgical procedure was performed, or the surgery was canceled. After informed consent was obtained, 3D lung reconstructions were constructed using open-source 3D Slicer software. The system usability score (SUS) questionnaire assessed the usability of these reconstructions, whilst performance was evaluated based on anatomical validity compared to prior 2D CT assessment as well as operative findings. Descriptive statistics were reported. Results: Thirteen patients were included, of whom one underwent a segmentectomy. Eighty-three percent of the 3D lung reconstructions scored above average (SUS >68). Compared to 2D CT scans, 38% of lung nodule segmental locations were detected more accurately through 3D lung reconstructions. Furthermore, 3D lung reconstructions revealed anatomical variations in 62%, which were not recognized on 2D CT scans, and provided surgeons with insights that would change the procedure and/or transection planes in 62%. One 3D lung reconstruction failed to demonstrate an intraoperative recognized segmental pulmonary artery (A6) branch. Conclusions: Three-dimensional lung reconstructions created with open-source software were usable and effective for uniportal VATS anatomical resections. Trial Registration: ClinicalTrials.gov/NCT06132607.

Clinical value of low-dose three-dimensional reconstruction by multi-slice spiral computed tomography and by traditional X-ray in the diagnosis of distal radius epiphyseal injury in children.

OBJECTIVE: To compare the clinical value of multi-slice spiral computed tomography (MSCT) low-dose three-dimensional reconstruction and traditional X-ray in the auxiliary diagnosis of distal radius epiphyseal injury in children. METHODS: A retrospective analysis was performed on 105 children with distal radius bone scale injury (classified by Salter-Harris classification) admitted from March 2020 to June 2022. All children underwent MSCT three-dimensional reconstruction examination and traditional X-ray examination. The detection rate of epiphyseal injury of the distal radius was compared, along with the resolution, sensitivity and specificity. The image clarity and display degree of bone structure were analyzed. The radiation dose-related indicators and the time required for diagnosis were compared. RESULTS: The detection rate and diagnostic accuracy of MSCT (100%, 92.38%) was significantly higher than that of X-ray (76.19%, 64.76%). In terms of radiation dose index, the volume dose index CTDI of MSCT ranged from 1-5 mGy while the X-ray group ranged from 5-10 mGy. The dose length product (DLP) value of the MSCT group was lower than in the X-ray group (20-100 mGy·cm vs. 50-150 mGy·cm). The diagnostic scan time for MSCT was shorter than that of conventional X-ray. The acceptance rate with MSCT was 99%, significantly higher than that with conventional X-ray (85%). CONCLUSIONS: Low-dose three-dimensional reconstruction of MSCT in the diagnosis of epiphyseal injury of distal radius in children shows significant advantages over traditional CT in the detection rate, diagnostic accuracy, postoperative reduction quality evaluation, and radiation dose.

The Optimal Head Position Following Intratympanic Injection: A Research Based on HRCT Reconstruction.

Objective: This study aimed to investigate the optimal head position (OHP) following intratympanic injection, a critical intervention in treating inner ear disorders. Identifying OHP is essential to maximize drug retention in the middle ear, thereby significantly enhancing the therapeutic efficacy by mitigating the significant issue of injectate leakage through the eustachian tube (ET). Exploratory various positions of ET orifice and round window (RW) were investigated and associated with head movements. Methods: Twenty-two (10 males and 12 females) anonymized high-resolution computed tomography (HRCT) datasets of patients without structural ear disease were selected from January 2022 to December 2022 in the study. The subjects were categorized into two groups: children (≤18 years) and adult group (>18 years). The reconstruction of the ET orifice and RW from HRCT were analyzed using Mimics software and the distances from the center point of ET orifice or the center point of RW to the reference plane were defined as distance of ET orifice (DET) and distance of RW (DRW). Results: In the supine position, the OHP for intratympanic injection was 23°of pronation and 24° of posterior extension, and the maximum distance between the ET orifice and RW (DET-RW) was 9.29 ± 2.13 mm. As the head position extended posteriorly beyond 43°, DET was relatively high compared with DRW, resulting in the OHP a fully posteriorly extended 90° of the head being the optimal position with DET-RW of 2.13 ± 1.60 mm in the supine position, however, it is not realized in human beings. Moreover, the OHP had no obvious relevance corresponding to age following intratympanic injections. Conclusion: Our study suggested that OHP after intratympanic injections treatment consists of supine position, along with a slight pronation and posterior extension.

Three-Dimensional Reconstruction and Visualization of Underwater Bridge Piers Using Sonar Imaging.

The quality of underwater bridge piers significantly impacts bridge safety and long-term usability. To address limitations in conventional inspection methods, this paper presents a sonar-based technique for the three-dimensional (3D) reconstruction and visualization of underwater bridge piers. Advanced MS1000 scanning sonar is employed to detect and image bridge piers. Automated image preprocessing, including filtering, denoising, binarization, filling, and morphological operations, introduces an enhanced wavelet denoising method to accurately extract the foundation contour coordinates of bridge piers from sonar images. Using these coordinates, along with undamaged pier dimensions and sonar distances, a model-driven approach for a 3D pier reconstruction algorithm is developed. This algorithm leverages multiple sonar data points to reconstruct damaged piers through multiplication. The Visualization Toolkit (VTK) and surface contour methodology are utilized for 3D visualization, enabling interactive manipulation for enhanced observation and analysis. Experimental results indicate a relative error of 13.56% for the hole volume and 10.65% for the spalling volume, demonstrating accurate replication of bridge pier defect volumes by the reconstructed models. Experimental validation confirms the method's accuracy and effectiveness in reconstructing underwater bridge piers in three dimensions, providing robust support for safety assessments and contributing significantly to bridge stability and long-term safety assurance.

Skeletal Muscle Complex Between the Vagina and Anal Canal: Implications for Perineal Laceration.

INTRODUCTION AND HYPOTHESIS: The anatomy of the skeletal muscles located between the vagina and anus is important during complex obstetric laceration reconstructions. We aimed to clarify the composition of skeletal muscles located between the vagina and anal canal and their three-dimensional configuration relevant to perineum repair. METHODS: This observational study involved ten female cadavers. An anatomical dissection was performed to observe the muscles around the vagina and anal canal. Immunohistological analysis of the midsagittal section was performed to clarify the composition of the muscles, and dissection was performed to correspond to the cross-section. Wide-range serial sectioning and three-dimensional reconstruction were used to support these findings histologically and visualize the three-dimensional arrangement. RESULTS: The region between the vagina and anal canal included the anterior part of the external anal sphincter, superficial transverse perineal muscle approaching from the lateral side, and levator ani, located cranially. They converge three-dimensionally in the median from each direction, forming a muscle complex between the vagina and anal canal. CONCLUSIONS: The medial region between the vagina and anal canal in those giving birth includes a skeletal muscle complex formed by the confluence of the external anal sphincter, anterior bundle of the levator ani, and superficial transverse perineal muscle. In cases of severe perineal lacerations, these muscles could be injured. The anatomical knowledge that a part of the levator ani forms a muscle sling anterior to the anal canal is particularly important for obstetricians and gynecologists repairing obstetric lacerations and treating pelvic floor disorders.

Anatomical characteristics of superior and subsuperior segment in right lower lobe based on three-dimensional reconstruction.

OBJECTIVE: Segmentectomy has been widely performed in clinical practice, which required a comprehensive understanding of anatomical structure. In right lower lobe, studies of superior segment (S6) were relatively small-sized. And only one study focusing on subsuperior segment (S∗) was published, which showed different results with previous ones. As the close relationship between S6 and S∗, variation types and their prevalence rate were reported, aiming to providing larger-size study of S6 and showing new evidence on anatomical structure of S∗. METHODS: 800 CT imaging data were collected from patients in our hospital. Three-dimensional reconstruction was performed after quality check. All images were screened according to the definition of corresponding segment and anatomical variations were analyzed. RESULTS: The proportion of S6 variation types in the largest scale (718 patients) was reported with no significant difference compared to previous studies and newly classified subtypes of two-stem V6. The prevalence rate for S∗ in right lower lobe reached 28.3 % (203/718) with similar proportion of three types. Variation types and origins of pulmonary artery were analyzed in detail, finding two-stem A∗ only be observed in type III B∗. CONCLUSIONS: Through this study, the variation types and incidence rate of S6 were confirmed, and a different result of S∗ has been provided as well. The feasibility of the current classification standards and proposed new subclassifications were verified. The results would be a supplement to lung segmental anatomy and could advance researches in the future.