An Automatic Method for Elbow Joint Recognition, Segmentation and Reconstruction.

Elbow computerized tomography (CT) scans have been widely applied for describing elbow morphology. To enhance the objectivity and efficiency of clinical diagnosis, an automatic method to recognize, segment, and reconstruct elbow joint bones is proposed in this study. The method involves three steps: initially, the humerus, ulna, and radius are automatically recognized based on the anatomical features of the elbow joint, and the prompt boxes are generated. Subsequently, elbow MedSAM is obtained through transfer learning, which accurately segments the CT images by integrating the prompt boxes. After that, hole-filling and object reclassification steps are executed to refine the mask. Finally, three-dimensional (3D) reconstruction is conducted seamlessly using the marching cube algorithm. To validate the reliability and accuracy of the method, the images were compared to the masks labeled by senior surgeons. Quantitative evaluation of segmentation results revealed median intersection over union (IoU) values of 0.963, 0.959, and 0.950 for the humerus, ulna, and radius, respectively. Additionally, the reconstructed surface errors were measured at 1.127, 1.523, and 2.062 mm, respectively. Consequently, the automatic elbow reconstruction method demonstrates promising capabilities in clinical diagnosis, preoperative planning, and intraoperative navigation for elbow joint diseases.

Determining Macromolecular Structures Using Cryo-Electron Microscopy.

Structural insights into macromolecular and protein complexes provide key clues about the molecular basis of the function. Cryogenic electron microscopy (cryo-EM) has emerged as a powerful structural biology method for studying protein and macromolecular structures at high resolution in both native and near-native states. Despite the ability to get detailed structural insights into the processes underlying protein function using cryo-EM, there has been hesitancy amongst plant biologists to apply the method for biomolecular interaction studies. This is largely evident from the relatively fewer structural depositions of proteins and protein complexes from plant origin in electron microscopy databank. Even though the progress has been slow, cryo-EM has significantly contributed to our understanding of the molecular biology processes underlying photosynthesis, energy transfer in plants, besides viruses infecting plants. This chapter introduces sample preparation for both negative-staining electron microscopy (NSEM) and cryo-EM for plant proteins and macromolecular complexes and data analysis using single particle analysis for beginners.

Patients with trochlear dysplasia have dysplastic medial femoral epiphyseal plates.

PURPOSE: To investigate the growth of the epiphyseal plate in patients with trochlea dysplasia using a 3D computed tomography (CT)-based reconstruction of the bony structure of the distal femur. The epiphysis plate was divided into a medial part and a lateral part to compare their differences in patients with trochlear dysplasia. METHODS: This retrospective study included 50 patients with trochlea dysplasia in the study group and 50 age- and sex-matched patients in the control group. Based on the CT images, MIMICS was used to reconstruct the bony structure of the distal femur. Measurements included the surface area and volume of the growth plate (both medial and lateral), the surface area and capacity of the proximal trochlea, trochlea-physis distance (TPD) (both medial and lateral), and height of the medial and lateral condyle. RESULTS: The surface area of the medial epiphyseal plate (1339.8 ± 202.4 mm2 vs. 1596.6 ± 171.8 mm2), medial TPD (4.9 ± 2.8 mm vs. 10.6 ± 3.0 mm), height of the medial condyle (1.1 ± 2.5 mm vs. 4.9 ± 1.3 mm), and capacity of the proximal trochlear groove (821.7 ± 230.9 mm3 vs. 1520.0 ± 498.0 mm3) was significantly smaller in the study group than in the control group. A significant positive correlation was found among the area of the medial epiphyseal plate, the medial TPD, the height of the medial condyle and the capacity of the proximal trochlear groove (r = 0.502-0.638). CONCLUSION: The medial epiphyseal plate was dysplastic in patients with trochlea dysplasia. There is a significant positive correlation between the surface area of the medial epiphyseal plate, medial TPD, height of the medial condyle and capacity of the proximal trochlear groove, which can be used to evaluate the developmental stage of the trochlea in clinical practice and to guide targeted treatment of trochlear dysplasia. LEVEL OF EVIDENCE: III.

Molecular characteristics of multiple primary pulmonary nodules under a three-dimensional reconstruction model and relevant multi-omics analyses: a case report.

Background: In addition to CT images and pathological features, many other molecular characteristics remain unknown about multiple primary lung cancer (MPLC) from intrapulmonary metastatic lung cancer. Case presentation: In this study, we reported a patient with an early-stage MPLC with both adenocarcinoma in situ (AIS) subtype and minimally invasive adenocarcinoma (MIA) subtype. The patient was diagnosed with more than 10 nodules and underwent precise surgery assisted by three-dimensional (3D) reconstruction at the left upper lung lobe. Whole-exome sequencing (WES) and multiple immunohistochemistry (mIHC) were performed to reveal the genomic profiling and tumor microenvironments of multiple nodules in this patient with MPLC. Based on 3D reconstruction location information, we found that the genomic and pathological results of adjacent lymph nodes were quite different. On the other hand, PD-L1 expression and the proportion of infiltrating lymphocytes in tumor microenvironments were all at a low status and did not vary in adjacent lymph nodes. Additionally, maximum diameter and tumor mutational burden levels were found to be significantly associated with CD8+ T cell proportion (p<0.05). Besides, CD163+ macrophages and CD4+ T cell proportion were higher in MIA nodules than in AIS nodules (p<0.05). This patient reached a recurrence-free survival of 39 months. Conclusion: Generally, in addition to CT imaging and pathological results, genomic profiling and tumor microenvironments may facilitate identifying the potential molecular mechanisms and clinical outcomes in patients with early-stage MPLC.

Thermal Ablation of Liver Tumors Guided by Augmented Reality: An Initial Clinical Experience.

Background: Over the last two decades, augmented reality (AR) has been used as a visualization tool in many medical fields in order to increase precision, limit the radiation dose, and decrease the variability among operators. Here, we report the first in vivo study of a novel AR system for the guidance of percutaneous interventional oncology procedures. Methods: Eight patients with 15 liver tumors (0.7−3.0 cm, mean 1.56 + 0.55) underwent percutaneous thermal ablations using AR guidance (i.e., the Endosight system). Prior to the intervention, the patients were evaluated with US and CT. The targeted nodules were segmented and three-dimensionally (3D) reconstructed from CT images, and the probe trajectory to the target was defined. The procedures were guided solely by AR, with the position of the probe tip was subsequently confirmed by conventional imaging. The primary endpoints were the targeting accuracy, the system setup time, and targeting time (i.e., from the target visualization to the correct needle insertion). The technical success was also evaluated and validated by co-registration software. Upon completion, the operators were assessed for cybersickness or other symptoms related to the use of AR. Results: Rapid system setup and procedural targeting times were noted (mean 14.3 min; 12.0−17.2 min; 4.3 min, 3.2−5.7 min, mean, respectively). The high targeting accuracy (3.4 mm; 2.6−4.2 mm, mean) was accompanied by technical success in all 15 lesions (i.e., the complete ablation of the tumor and 13/15 lesions with a >90% 5-mm periablational margin). No intra/periprocedural complications or operator cybersickness were observed. Conclusions: AR guidance is highly accurate, and allows for the confident performance of percutaneous thermal ablations.

Effects of Fixed-Point Lateral Flexion and Rotation Manipulation on Intervertebral Foramina Morphology of Cervical Spondylotic Radiculopathy / 医用生物力学

Objective To analyze the changes in morphology of intervertebral foramina in patients with cervical spondylotic radiculopathy (CSR) treated with fixedpoint lateral flexion and rotation manipulation based on three-dimensional (3D) reconstruction technology, so as to provide references for the effectiveness of manipulation treatment. MethodsForty patients with CSR were treated with fixed point lateral flexion and rotation manipulation once every other day for a total of 7 times and 2 weeks as a course of treatment. CT data of the patients before and after treatment were analyzed by using multifunctional CT, Mimics 21.0, Geomagic and SolidWorks 2017. The area of the intervertebral foramen, anterior and posterior diameter of the intervertebral foramen, upper and lower diameter of the intervertebral foramen were measured before and after treatment, as well as the infrared thermal imaging temperature differences of the bilateral neck and shoulder, front and back of the upper limb, and the VAS scores of the patients were observed before treatment, 7 d after treatment, 14 d after treatment and 1 month follow-up. Results Foraminal area, anterior and posterior diameters, upper and lower diameters of 40 patients were improved after treatment, and the temperature differences of infrared thermal imaging of patients before and after treatment were statistically significant. The VAS score of the patients decreased progressively. Conclusions Fixed point lateral flexion manipulation can significantly improve the shape of the intervertebral foramen in patients with CSR, so as to achieve the treatment purpose of relieving nerve compression.

A study of three-dimensional reconstruction and printing models in two cases of soft tissue sarcoma of the thigh.

PURPOSE: The aim of our study was to demonstrate the value of three-dimensional (3D) reconstruction and three-dimensional printing (3DP) models in two cases of soft tissue sarcoma (STS) of the thigh. MATERIALS AND METHODS: Two patients with STS were recruited and underwent enhanced CT and MRI scans. Then, the 3D models were reconstructed and printed using the obtained data, and five experts were invited to assess the segmentation quality. In addition, 34 junior, intermediate and senior general surgeons were recruited to demonstrate the value of 3D models in preoperative planning and invited five surgeons to complete the assessment of 3D models-assisted intraoperative navigation. Finally, 32 interns were enrolled to explore the significance of 3D models in medical education. RESULTS: All experts agree with the accuracy of the 3D models. The application of 3D models in preoperative planning improved the understanding of general surgeons (P = 0.000, P = 0.000, P = 0.000). After the planning tools were exchanged between the two groups, senior surgeons in group A showed more significant improvements in performance than junior and intermediate surgeons in group A (P = 0.001, P = 0.006). Surgeons unanimously agree on the value of 3D models in intraoperative navigation. When applied for the education of medical interns, these models could enhance their understanding of pathologic anatomies (P = 0.036). CONCLUSION: In two operations for STS of the thigh with complex adjacencies, our study demonstrates that 3D models are of great value for preoperative planning, intraoperative navigation and medical education. More importantly, these models were more helpful to senior general surgeons.

Application of Three-dimensional Reconstruction in Single Utility-port Thoracoscopic Segmentectomy for Early Stage Non-small Cell Lung Cancer: A Propensity Score-matched Analysis / 肿瘤防治研究

Objective To evaluate the clinical value of 3D reconstruction in the single utility-port thoracoscopic segmentectomy of early stage NSCLC by propensity score matching (PSM). Methods We retrospectively analyzed clinical data of 150 early stage NSCLC patients undergoing single utility-port thoracoscopic segmentectomy. The patients were divided into reconstruction group (n=58) and non-reconstruction group (n=92) according to 3D reconstruction. PSM was performed on two groups to compare perioperative outcomes. Results Procedures were successfully completed on all patients, without perioperative death. In each group, 43 patients were successfully matched after PSM on the basis of 8 confounding factors, age, gender, smoking status, BMI, maximum tumor diameter on CT, tumor location, % FEV1 and type of planned segmentectomy. After PSM, in complex segmentectomy, the patients in the reconstruction group had shorter operation time (155.77±30.17 vs. 212.94±66.49min, P < 0.001) and less blood loss (46.00±25.94 vs. 88.79±68.36ml, P=0.002), compared with the non- reconstruction group. Conclusion Preoperative 3D reconstruction could help improve the efficiency of single utility-port thoracoscopic surgery for complex segmentectomy and reduce intraoperative bleeding.

Hemodynamic Analysis on Proximal End of the Aortic Dissection with Different Rupture Shapes / 医用生物力学

Objective To explore hemodynamic performance of the aortic dissection after lesions, so as to provide a more scientific basis for patient treatment. Methods Based on computed tomography angiography (CTA) image data from a patient with complex Stanford B-type aortic dissection, the personalized aortic dissection models with different rupture shapes (H-type, O-type, and V-type) at proximal end of the aortic dissection were established. Combined with computational fluid dynamics (CFD) and morphological analysis method, distributions of the velocity at rupture section, the blood flow, the wall pressure and the wall shear stress (WSS) were analyzed. Results The flow velocity, the highest pressure difference and the WSS proportion at entrance of the H-shaped rupture showed larger hemodynamic parameters than those of the other two types. The risk of dissection rupture for type H was the largest, while type V was in the middle, and type O was the smallest. Conclusions This study provides an effective reference for further numerical analysis the cases and formulation of treatment plans.

Research Method for Numerical Simulation on Upper Respiratory Tract Airway State Based on 3D Printing and CT Reconstruction / 医用生物力学

Objective To establish a comprehensive method combining physical model experiment and numerical simulation for studying airflow state of upper respiratory tract. Methods Based on CT medical images published online, a three-dimensional (3D) model of human upper respiratory tract was reconstructed. Based on 3D printing technology, an experimental model of the upper respiratory tract was established and the flow process of respiration was measured. A numerical simulation model was created based on the meshing of upper respiratory tract model and the turbulent Realizable k-ε model. Results Firstly, the result of numerical simulation was compared with the experimental conditions, and good agreement was achieved. The numerical simulation results showed that the airflow in respiratory process was in a parabolic shape; the distribution of flow field, pressure on wall and vortex structure were different between inspiratory and expiratory phases; there were air residues in the upper and lower nasal passages during the respiratory exchange process. In addition, the effects of airflow on physiological environment of the upper respiratory tract were preliminarily analyzed through the steak line, pressure field and vortex structure distribution. Conclusions The method proposed in this paper has the characteristics of pertinence, rapidity and accuracy, which gives full play to the advantages of reliable physical experiments and fine numerical simulation, and is applicable for studying different problems of the upper respiratory tract in different cases, with a high value for personalized diagnosis and treatment in clinic.

Versatile Undergraduate Neurobiology Course-Based Research Experiences Using Open Access 3D Electron Microscopy Image Volumes.

Course-based undergraduate research experiences (CUREs) using inquiry-based methodology provide a range of positive benefits to undergraduates and instructors. Yet, the required time and cost in designing and running CUREs with detailed data acquisition steps can lead to barriers in CURE implementation. This report describes an alternative approach to CUREs that utilizes free, open access 3D image volumes as data-rich resources for neurobiology CUREs. These open access image volume CUREs (ivCUREs) effectively combine the data acquisition and analysis steps within the course, allowing more time for students to critically evaluate their hypotheses and results, compare data with peers, and reflect on their experiences. Undergraduates in this 10-week ivCURE analyzed >670 excitatory synapses across two brain areas for the presence and origins of spinules within presynaptic boutons, and fully reconstructed 13 of these synapses in 3D. These data highlight the prevalence of these enigmatic synaptic features within excitatory presynaptic boutons, and their potential importance to neuronal function. Moreover, these results underscore key benefits to ivCURE implementation, including the (1) low-cost of experimental design and implementation, (2) ability to utilize the same data-rich image volume across multiple ivCUREs, (3) potential to generate publishable analyses, and (4) flexibility to scale projects and class sizes up at little to no cost. Opportunities for undergraduates to engage in inquiry-based ivCUREs that examine a host of unexplored questions in neurobiology will continue to grow, in parallel with rapid advances in 3D microscopy techniques and the increased availability and diversity of open access image volumes and analytical tools.

Finite Element Simulation of AnyBody-Based Musculoskeletal Multi-Body Dynamics / 医用生物力学

Objective To investigate the method of modeling, finite element modeling and AnyBody musculoskeletal multi-body dynamics simulation technique analyze the biomechanics of clinical orthopaedic surgery. Methods The AnyBody software was used to establish the musculoskeletal motor model of the individualized upper limbs according to the height, weight and CT data of the volunteers. The flexion motion of the elbow in normal people was simulated, and the muscle force, joint force, torque, constraint condition of the humerus during the flexion movement were derived and used as the boundary conditions of finite element analysis.Then, the 3D reconstruction was conducted in the MIMICS software based on CT data. In the Geomagic Studio software, the humeral curved surface and position coordinate matching were completed, and grid division and material assignment were done in the HyperMesh software. Finally, the 3D reconstruction for finite element model of the humerus was introduced into ABAQUS software. The boundary condition data derived from the AnyBody software were applied and the stress calculation analysis was performed. Results The results of the stress and displacement of the humerus during elbow flexion motion were calculated in the ABAQUS software. The maximum stress and displacement of the humerus were 0.76 MPa and 20 μm when flexion of the elbow joint was about 90°. Conclusions A continuous dynamic analysis of humeral stress and displacement during elbow flexion motion was realized, which was more consistent with the requirements of human physiological anatomy and could provide an efficient analysis platform and a new way for studying clinical orthopedic problems.

Three-dimensional reconstruction of the temporal bone: Comparison of in situ, CT, and CBCT measurements.

OBJECTIVE: To evaluate the accuracy of three-dimensional (3D) Cone Beam Computed Tomography (CBCT) and Computed Tomography (CT) reconstructions of human temporal bones compared with in situ measurements. MATERIAL AND METHODS: Experimental anatomical study of 10 human temporal bones. Wilcoxon's test was used to compare 8 distances on each temporal bone measured in situ and then on 3D CT and CBCT reconstructions. Six landmarks were used: external auditory canal (EAC), tip of the mastoid process, tip of the occiput, zygoma, a point situated 1cm above the tip of the mastoid process (T0) (open technique: lower limit of the mastoidectomy), head of stapes. RESULTS: No significant difference was observed between the 3 measuring techniques for any of the distances studied (P>0.05). DISCUSSION: This study demonstrates the equivalence of CBCT and CT for temporal bone measurements. CONCLUSION: CBCT is a new imaging modality providing 3D reconstructions of the temporal bone that are as reliable as those obtained by CT. As a result of better spatial resolution compared to CT, CBCT is associated with a significantly lower radiation dose. This technique constitutes a morphological progress, as CBCT is comparable to CT, allowing investigation of pathological ears with a lower radiation dose.

Through the HoloLens™ looking glass: augmented reality for extremity reconstruction surgery using 3D vascular models with perforating vessels.

Precision and planning are key to reconstructive surgery. Augmented reality (AR) can bring the information within preoperative computed tomography angiography (CTA) imaging to life, allowing the surgeon to 'see through' the patient's skin and appreciate the underlying anatomy without making a single incision. This work has demonstrated that AR can assist the accurate identification, dissection and execution of vascular pedunculated flaps during reconstructive surgery. Separate volumes of osseous, vascular, skin, soft tissue structures and relevant vascular perforators were delineated from preoperative CTA scans to generate three-dimensional images using two complementary segmentation software packages. These were converted to polygonal models and rendered by means of a custom application within the HoloLens™ stereo head-mounted display. Intraoperatively, the models were registered manually to their respective subjects by the operating surgeon using a combination of tracked hand gestures and voice commands; AR was used to aid navigation and accurate dissection. Identification of the subsurface location of vascular perforators through AR overlay was compared to the positions obtained by audible Doppler ultrasound. Through a preliminary HoloLens-assisted case series, the operating surgeon was able to demonstrate precise and efficient localisation of perforating vessels.

Optimal three-dimensional reconstruction for lung cancer tissues.

The existing three-dimensional (3D) x-ray reconstruction methods for lung cancer tissue reconstruct the investigated objects based on a series of two-dimensional (2D) image sections and a chosen 3D reconstruction algorithm. However, because these procedures apply the same segmentation method for all 2D image sections, they may not achieve the optimal segmentation for each section. As a result, the reconstructed 3D images have limited spatial resolution. Furthermore, the existing 3D reconstruction method is time-consuming and results in a limited time resolution. This research presents an innovation of 3D reconstruction by reformulating two main components of the method. First, a validity index for fuzzy clustering is used to obtain the optimal segmentations of any 2D x-ray image. The process is realized by automatically determining the optimal number of clusters for the image. Second, unlike the existing 3D reconstruction methods, a fast-FCM algorithm is used to speed up the 2D image segmenting process, thereby raising the time resolution of the 3D reconstruction process. With the aid of commonly used VTK software, the proposed method has been used to visualize four classes of typical lung cancer tissues: adenocarcinoma, large cell carcinoma, small cell carcinoma, and squamous cell carcinoma. Experimental results validate the effectiveness and efficiency of the proposed algorithm. Thus, the method contributes a useful tool for x-ray-based 3D image reconstruction.

Malignant pheochromocytoma in the anterior mediastinum with sternal invasion: a case report.

Pheochromocytomas are catecholamine-producing neuroendocrine tumors that usually occur in the adrenal medulla or sympathetic paraganglia. Anterior mediastinum involvement with pheochromocytoma is rare and may not present with typical symptoms. Its clinical manifestation may be unclear and a high index of suspicion is required for accurate diagnosis. We report a rare case of pheochromocytoma of the anterior mediastinum in a 51-year-old female. A painful hard mass on the sternum was the only clinical manifestation. Imageological examination indicated that there might be a malignant mass on the anterior mediastinum and thoracic wall. The patient accepted surgical curettage and thoracic wall reconstruction. Based on pathological results and WHO definition, the final diagnosis was malignant pheochromocytoma. After six months follow-up, the patient had no recurrence or any symptom. Malignant pheochromocytoma in the anterior mediastinum invading the sternum is rare. A local painful mass may be the only clinical manifestation without special laboratory results. Surgery remains as the first choice for these patients. For this rare case, 3D reconstruction by special software may be a good method to realize individualized treatment. The final decision of the diagnosis should be based on pathological results, past medical history and WHO definition. Long-term follow-up is necessary, while other suspicious lesions should also be given sufficient attention.

Three-dimensional reconstructions in spine and screw trajectory simulation on 3D digital images: a step by step approach by using Mimics software.

There is a rapidly increasing amount of literature outlining the use of three-dimensional (3D) reconstruction and printing technologies in recent years. However, precise instructive articles which describe step-by-step methods of reconstructing 3D images from computed tomography (CT) or magnetic resonance imaging (MRI) remain limited. To address these issues, this article describes a detailed protocol which will allow the reader to easily perform the 3D reconstruction in their future research, to allow investigation of the appropriate surgical anatomy and allow innovative designs of novel screw fixation techniques or pre-operative surgical planning.

Evaluation of a large adrenal carcinoma with 3D reconstruction of computed tomography images: A case report and literature review.

Adrenocortical carcinoma (ACC) is an extremely rare disease caused by a cancerous growth in the adrenal cortex. Although most of adrenal tumors are benign, the functional ACC is malignant resulting in endocrine dysfunction and necessitates surgical removal. Retroperitoneal laparoscope adrenalectomy is often used to perform adrenal gland surgery. Here, we reported a case of huge ACC with the size of 6.8 cm × 5.2 cm. To achieve better surgical outcome, we integrated 3D reconstructed CT images into a dynamic video for preoperative planning and intraoperative guiding to resect the diseased adrenal gland completely without neighbor organ's injury and surgery complications. Moreover, we reviewed associated applications using 3D reconstructed CT imaging in surgery field. Finally, the evaluation and effect of such technology were discussed to reveal that the 3D dynamic video can help surgeon to make better preoperative assessment so as to give patients better therapy.

Efficacy of reciprocating and rotary systems for removing root filling material: a micro-computed tomography study.

This study aimed to use micro-computed tomography (micro-CT) imaging to evaluate the efficacy of the reciprocating and rotary systems for the removal of root filling materials in comparison with hand files. Thirty maxillary incisor teeth were prepared with ProTaper Universal (PTU) system, filled using cold lateral condensation and randomly divided into three groups of ten teeth each. The root fillings were removed with WaveOne Reciprocating and ProTaper Universal Re-treatment (PTU-R) systems and hand files. Micro-CT was used to scan the specimens before and after each treatment step. Percentage of volume of residual root filling was measured. The operating time was recorded. PTU-R instruments yielded better results for removing filling material, even though there was no statistically significant difference between PTU-R and WaveOne groups. Reciprocating and rotary systems showed similar performances in terms of efficacy and operating time for root filling removal.