Virtual surgery for choledocholithiasis

To study the surgery plan and simulation effect of the three dimensional (3D) hepatic virtual operation based on the data of 64-slice helical CT scanning and to probe the feasibility of the virtual operation based on the FreeForm Modeling System. The volunteer liver was scanned to collect two dimensional (2D) DICOM data of 64-slice helical CT scanning and the 3D hepatic and intrahepatic vessels model were reconstructed by MIMICS software. The reconstructed liver, the intrahepatic vessels model and the artificial tumor models were output into the FreeForm Modeling System in the STL format. The device PHANTOM with the characterization of dynamo-feedback was applied to make the operation on the 3D hepatic. The spatial relationship between the tumour and the intrahepatic vessels were clearly observed by rotation and enlargement of the target. According to the operation principle, the left lobe of liver resection was simulated by manipulating the device PHANToM. Through the liver transparence surface, the intrahepatic vessels were easily distinguished. The operation procedure was accord with the clinic hepatic surgery. Meanwhile, during the operation, by adjusting the incision objective intensity, the dynamo-feedback intensity was definitely touched. By using the FreeForm Modeling System,the hepatic operation procedure can be simulated ahead of time. The operation complication in the practical surgery can be anticipated and the individualization operation schema can be reasonable instituted.

Objective To investigate the clinical application value of anterolateral thigh flap based on computer tomography angiography (CTA) and three-dimensional reconstruction in repair of oral and maxillofacial defects. Methods Preoperative CTA examination was performed on 12 cases of patients with oral and maxillofacial defect which was going to be repaired by anterolateral thigh flap. Image segmentation and 3D reconstruction were preformed by IntelliSpace Portal Philips software to determine the size, distribution, and three-dimensional anatomic relationship of the lateral femoral artery with the peripheral tissues. Point and area of anterolateral thigh flap was signed on the donor skin according to the image. The distribution of descending and perforating branches of lateral circumflex femoral artery was checked in operation, and individual flap based on size and shape of defected area was transplanted to the recipient site to repair the defect. Results The origination, structure of descending and perforating branches of lateral circumflex femoral artery as well as the three-dimensional anatomic relationship with its peripheral tissues can be displayed well by the CTA. During operation, the position and structure of perforator flaps were consistent with the result of pre-operative examination, the vessel position of recipient site was consistent with the result of pre-operative examination. The patients were followed up for 6-24 months. Twelve flaps survived completely and the shape and function of recipient site was good. Conclusions CAT and three-dimensional reconstruction can display three-dimensional anatomic stracture of flap vessel and its branches, which is a guidence for cutting and transplanting flap. Key words: Oral and maxillofacial; Tissue defect; Angiography; Three-dimensional reconstruction; Anterolateral thigh flap

To study the three-dimensional (3D) reconstruction and the visualization simulation surgery of spleen based on the scanning data of 64-slice helical computed tomograph (CT). The original data of 64-slice helical CT of spleen was collected, and then the CT image sequences were segmented and automatically extracted using auto-adapted region growth algorithm, and were conducted with the segmented images by adopt self-developed image processing software for 3D reconstruction. Finally, the 3D models were imported into FreeForm Modeling System for modifying and smooth. And the visualization simulation surgery was performed before splenectomy. It was fast and effective to utilize auto-adapted region growth algorithm to conduct spleen image program segmentation; the reconstructed models were seen clearly and could reappear the structure of the spleen and the important surrounding organs. The effect of the splenectomy simulation surgery was similar to the practical surgery. The research on 3D models of spleen and visualization simulation surgery of splenectomy could lead to clinical benefits. It maybe improve the surgical effect and decrease the surgical risk and reduce the complication demonstrating visualized operation before surgery.

Objective To apply imaging examinations for surveying the morphological characteristics of neurocentral synchondrosis (NCS) in fetal spine so as to deduce the function of NCS in the growth of vertebra and vertebral pedicle in normal spines. Methods A total of 15 fetal samples (23 w-33 w) without congenital spinal deformity were collected from October 2012 to December 2013. There were 8 males and 7 females with an average gestational age of 28+ 6 weeks. And informed consent form was signed. Based upon fetal age, the fetuses were divided into two groups of 7 samples (24 w) and 8 samples with an average gestational age of 32 w. All fetuses were visualized by magnetic resonance imaging (MRI) (T1-L5 vertebra) and full-spine spiral computed tomography (CT) + three-dimensional (3D) reconstruction. The above methods could observe the 3D morphology of NCS. Then the relevant parameters were measured by dicom image processing software. And the mean value of each group was calculated and line plotted by Origin software. All parameters of both sides were analyzed by paired t-test. And the test standard was set at P=0.05. Results As a pair of triangular structure with a wide exterior and a narrow interior in sagittal plane on T2 MRI image, NCS surrounds both vertebral body and posterior arch and inter-connected in anterior aspects. And it is reconstructed by two parallel lines perpendicular to vertebrae in sagittal plane on full-spine spiral CT + 3D reconstruction images. The mean parameters of two groups were calculated and the corresponding lines plotted. It showed that α angle increased faster than that of the second one. The others parameters of the second fetal group were bigger than those of the first one. The mean α angles of left and right sides were 60.827°±2.794° and 60.882°±2.840° for the first group and 58.878°±4.194 and 58.749±4.334 for the second group respectively. And the bilateral length-width ratios were 1.452±0.096 and 1.435±0.124 for the first group and 1.680±0.147 and 1.678±0.142 for the second group. The parameters of two groups were compared by paired t-test and the differences of two sides of two group were significant (P 0.05). Conclusions The position of NCS shifts constantly. It accounts for a bigger volume of vertebral body in fetal spines. And its role for the growth of spine is larger than that in infants and young children. Key words: Vertebral column; Fetus; Cartilage

An optimal protocol for clearing the cervical spine in unconscious patients with traumatic brain injury remains controversial. Protocols include plain radiographs and computed tomography (CT), and ligamentous injury may be identified with flexion-extension radiographs. We questioned whether cervical CT with three-dimensional (3D) reconstructions may obviate the need for flexion-extension radiology in the detection of occult ligamentous injury. Between July 1999 and November 2001, 276 unconscious traumatic brain injured patients admitted to The Alfred Hospital received cervical spine plain radiographs, CT with 3D reconstructions, and dynamic flexion-extension X-ray studies with fluoroscopy as part of a routine protocol. These patients were identified from a prospective intensive care unit database and all radiology reports were reviewed. Dynamic flexion-extension X-ray studies with fluoroscopy identified no new fractures or instability; there were no instances of true-positive results. Dynamic flexion-extension was true-negative in 260 of 276 (94%) patients, falsely positive in six patients (2.2%) and falsely negative in one (0.4%) patient. In nine patients, dynamic flexion-extension was inadequate. Dynamic flexion-extension X-ray studies with fluoroscopy delayed cervical spine clearance and were almost always reported as normal. In a cervical spine clearance protocol for unconscious traumatic brain injury patients, dynamic flexion-extension X-ray studies with fluoroscopy did not identify any patients with cervical fracture or instability not already identified by plain radiographs and fine-cut CT (C0 to T2) with 3D reconstructions.

We herein describe the case of an adult with a complicated huge lymphangioma of the small bowel mesentery. Computed tomography (CT) confirmed a 45 × 30 × 14 cm multiple and separate, mixed and solid cystic tumor without enhancement by contrast medium in the abdominal cavity. Mesenteric CT angiography with three-dimensional (3D) reconstruction showed that the tumor did not involve the first jejunal artery, although the tumor did involve the subsequent jejunal and ileal arteries and the corresponding segment of the small bowel. Under anatomic guidance based on mesenteric CT angiography with 3D reconstruction, we were able to successfully excise the tumor. Mesenteric lymphangioma should be excised even when the tumor is asymptomatic. Mesenteric CT angiography with 3D reconstruction is useful for the surgical treatment of huge mesenteric tumors.

Objective Turn the CT sectional image into three-dimensional imaging based on VTK, in or-der to make better treatment programs for patients with liver cancer. Methods Establish visualization toolkit (VTK) visualization development environment based on VC6.0, obtain patient's CT images in DICOM format, use VTK filter and Laplacian sharpening template for pre-treatment of the images, and then use Ray-Casting algo-rithm for three-dimensional reconstruction. Results We can get three-dimensional images with higher resolu-tion and faster imaging speed through this method, which can also be cut, rotated and zoomed. Conclusion Ray-Casting algorithm based on VTK can be used for the three-dimensional imaging of human liver. With the as-sistance of three-dimensional images, doctors can detect the location of diseased tissue more easily and observe the shapes of diseased tissue intuitively. Key words: Liver tissue; Visualization toolkit; Three-dimensional reconstruction; Ray-Casting algorithm

To describe a system for measurement of the pretraumatic femoral antetorsion angle post-bilateral femoral shaft fracture with the use of new imaging software which allows segmentation and three dimensional (3D) reconstruction of DICOM (digital imaging and communications in medicine) images. This case involved a 20-year-old patient with bilateral femoral shaft fractures. Following initial clinical examination, CT scans of both femurs were performed. Subsequently, the DICOM datasets were uploaded to the new software tool. Following segmentation and 3D reconstruction, pretraumatic femoral antetorsion angles were determined. Femoral antetorsion was described and assessed in two ways by referring to the intersection of the posterior condylar plane and (1) a line drawn between the center of the femoral head and femoral neck, (2) a line drawn between the centers of the femoral head and greater trochanter. Using these definitions, values for femoral antetorsion were found to be, respectively, 20 degrees at the right fracture site and 19 degrees on the left site, and 33 degrees bilaterally. The investigators describe in this current technical report the use of new imaging software which enables the calculation of femoral AV following reduction of virtual fracture fragments which are created from standard DICOM images. We believe that this 3D reconstruction method of measuring the antetorsion angle can be integrated into a regular treatment algorithm and may potentially optimize clinical outcomes.

Hemifacial spasm (HFS), largely caused by neurovascular compression (NVC) of the facial nerve, is a rare condition characterized by paroxysmal, unilateral, involuntary contraction of facial muscles. It has long been suggested that these symptoms are due to compression at the transition zone of the facial nerve. The aim of this study was to examine symptom-free survival and long-term quality of life (QOL) in HFS patients who underwent microvascular decompression (MVD). A secondary aim was to examine the benefit of utilizing fused MRI and MRA post hoc 3D reconstructions to better characterize compression location at the facial nerve root exit zone (fREZ). The authors retrospectively analyzed patients with HFS who underwent MVD at a single institution, combined with a modified HFS-7 telephone questionnaire. Kaplan-Meier analysis was used to determine event-free survival, and the Wilcoxon signed-rank test was used to compare pre- and postoperative HFS-7 scores. Thirty-five patients underwent MVD for HFS between 2002 and 2018 with subsequent 3D reconstructions of preoperative images. The telephone questionnaire response rate was 71% (25/35). If patients could not be reached by telephone, then the last clinic follow-up date was recorded and any recurrence noted. Twenty-four patients (69%) were symptom free at longest follow-up. The mean length of follow-up was 2.4 years (1 month to 8 years). The mean symptom-free survival time was 44.9 ± 5.8 months, and the average symptom-control survival was 69.1 ± 4.9 months. Four patients (11%) experienced full recurrence. Median HFS-7 scores were reduced by 18 points after surgery (Z = -4.013, p < 0.0001). Three-dimensional reconstructed images demonstrated that NVC most commonly occurred at the attached segment (74%, 26/35) of the facial nerve within the fREZ and least commonly occurred at the traditionally implicated transition zone (6%, 2/35). MVD is a safe and effective treatment that significantly improves QOL measures for patients with HFS. The vast majority of patients (31/35, 89%) were symptom free or reported only mild symptoms at longest follow-up. Symptom recurrence, if it occurred, was within the first 2 years of surgery, which has important implications for patient expectations and informed consent. Three-dimensional image reconstruction analysis determined that culprit compression most commonly occurs proximally along the brainstem at the attached segment. The success of this procedure is dependent on recognizing this pattern and decompressing appropriately. Three-dimensional reconstructions were found to provide much clearer characterization of this area than traditional preoperative imaging. Therefore, the authors suggest that use of these reconstructions in the preoperative setting has the potential to help identify appropriate surgical candidates, guide operative planning, and thus improve outcome in patients with HFS.

Background: Prostate sarcoma is a malignant tumor from the prostate stroma. However, its pathogenesis is unknown. This is a rare type of prostate tumor. Case Presentation: A rare case of prostate leiomyosarcoma has been described. A 55-year-old prostate leiomyosarcoma patient who suffered from progressive dysuria and frequent urination for half a year was examined. Pathology, immunohistochemical staining, and laparoscopic radical prostatectomy were performed using three-dimensional (3D) reconstruction to diagnose prostate leiomyosarcoma. The patient did not receive adjuvant therapy after the operation. Final pathology was used to confirm prostate leiomyosarcoma. After one year of follow-up, the patient regularly underwent a digital rectal examination and abdominal MRI. However, no tumor recurrence or metastasis was found. Discussion: We discussed diagnosis and treatment of prostate leiomyosarcoma and reviewd literatures. Conclusion: Prostate leiomyosarcoma is a rare special type of prostate tumor, and its diagnosis is mainly based on pathological features. Radical excision is the primary treatment for prostate leiomyosarcoma. The 3D reconstruction is essential in the surgery because it can determine the size of the tumor and its relationship to the surrounding tissue. A postoperative adjuvant therapy can also be performed.

Background:The accuracy of three-dimensional (3D) reconstructions from cone-beam computed tomography (CBCT) has been particularly important in dentistry, which will affect the effectiveness of diagnosis, treatment plan, and outcome in clinical practice. The aims of this study were to assess the linear, volumetric, and geometric accuracy of 3D reconstructions from CBCT and to investigate the influence of voxel size and CBCT system on the reconstructions results.Methods:Fifty teeth from 18 orthodontic patients were assigned to three groups as NewTom VG 0.15 mm group (NewTom VG; voxel size: 0.15 mm; n = 17), NewTom VG 0.30 mm group (NewTom VG; voxel size: 0.30 mm; n = 16), and VATECH DCTPRO 0.30 mm group (VATECH DCTPRO; voxel size: 0.30 mm; n = 17). The 3D reconstruction models of the teeth were segmented from CBCT data manually using Mimics 18.0 (Materialise Dental, Leuven, Belgium), and the extracted teeth were scanned by 3Shape optical scanner (3Shape A/S, Denmark). Linear and volumetric deviations were separately assessed by comparing the length and volume of the 3D reconstruction model with physical measurement by paired t-test. Geometric deviations were assessed by the root mean square value of the imposed 3D reconstruction and optical models by one-sample t-test. To assess the influence of voxel size and CBCT system on 3D reconstruction, analysis of variance (ANOVA) was used (α = 0.05).Results:The linear, volumetric, and geometric deviations were −0.03 ± 0.48 mm, −5.4 ± 2.8%, and 0.117 ± 0.018 mm for NewTom VG 0.15 mm group; −0.45 ± 0.42 mm, −4.5 ± 3.4%, and 0.116 ± 0.014 mm for NewTom VG 0.30 mm group; and −0.93 ± 0.40 mm, −4.8 ± 5.1%, and 0.194 ± 0.117 mm for VATECH DCTPRO 0.30 mm group, respectively. There were statistically significant differences between groups in terms of linear measurement (P < 0.001), but no significant difference in terms of volumetric measurement (P = 0.774). No statistically significant difference were found on geometric measurement between NewTom VG 0.15 mm and NewTom VG 0.30 mm groups (P = 0.999) while a significant difference was found between VATECH DCTPRO 0.30 mm and NewTom VG 0.30 mm groups (P = 0.006).Conclusions:The 3D reconstruction from CBCT data can achieve a high linear, volumetric, and geometric accuracy. Increasing voxel resolution from 0.30 to 0.15 mm does not result in increased accuracy of 3D tooth reconstruction while different systems can affect the accuracy.

Introduction Spontaneous Coronary Artery Dissection (SCAD) may be at the origin of up to 25% of acute coronary events in women &amp;lt;50 yo with no or few risk factors. The diagnosis of SCAD is challenging and in some cases it may be ascertained only by intracoronary imaging such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT). IVUS is widely available and has a better depth penetration compared to OCT, showing the extent of the false lumen and the aspect of the adventitia but its lower resolution does not always allow the visualization of smaller structures such as fenestrations. In a previous study we investigated the role of OCT in understanding the pathophysiology of SCAD and we reported a number of OCT complications. It is not known if these also apply to IVUS but since IVUS does not require additional contrast injection, the risk of false lumen (FL) propagation should be lower. Aim of the study To analyze the value of IVUS in the assessment of key features of SCAD and to explore the feasibility of three-dimensional (3D) reconstruction using IVUS imaging. Methods We collated the imaging findings of 15 cases of SCAD for which IVUS was used as part of routine clinical care. Images were assessed to determine the visualisation of the true lumen, the false lumen extent and its contents, the intima-media membrane, the presence of fenestrations, the external elastic lamina and underlying adventitia. Furthermore, we performed a 3D reconstruction of a type 2a dissection of the right coronary artery. The IVUS images were exported in DICOM format. The segmentation of the true and false lumens in the regions of interest was manually done using the ImageJ software. Subsequent images were processed using 3D Slicer and Paraview in order to obtain the 3D reconstruction of the dissected segment. Results The false lumen was entirely visible in 13/15 cases (87%) and the external elastic lamina in 12/15 cases (80%). In 3/15 cases (20%) the dissection was circumferential. The false lumen content had lower echogenicity compared to the surrounding tissue in all 15 cases. There was no visible fenestration. The 3D reconstruction (Figure 1) showed that the false lumen was larger than the true lumen. The general cross-sectional appearance was that of a “horseshoe” dissection but there was also a short segment of circumferential dissection and the intima-media membrane looked thickened. Conclusion Despite its resolution being lower than OCT, IVUS has a deep penetration and provides adequate imaging of the key features of SCAD. Perspectives We plan to further expand these findings in a larger series, intending to better characterize the false lumen and the adventitia in SCAD. IVUS findings in SCAD, 3D reconstruction Funding Acknowledgement Type of funding source: None

Image integration of three-dimensional (3D) reconstructions of left atrial (LA) and pulmonary vein (PV) anatomy into electroanatomical mapping (EAM) plays a major role in atrial fibrillation (AF) ablation. Point-by-point EAM is commonly used for registration of imported LA and PV anatomy. We aimed to assess the accuracy of intraprocedural rotational angiography-based LA imaging registered by spatial reconstruction of intracardiac echocardiography (ICE) in patients undergoing AF ablation. Twenty-two patients (11 males, 66 ± 12 years) were studied. Reconstructions of LA and PVs based on rotational angiography were registered by a second 3D reconstruction based on ICE. In a second step, EAM points were added to ICE 3D reconstructions. A 3D image of the LA and PVs was reconstructed in all patients by both imaging modalities. Rotational angiography and ICE-based LA 3D reconstructions took 11.5 ± 5.2 and 20.4 ± 11.2 min, respectively. A total of 17 ± 6 two-dimensional ICE fans were used for spatial reconstruction of ICE. The deviation between the two 3D shells was 2.6 ± 0.5 mm. Integration of 78 ± 58 EAM points into ICE 3D reconstruction did not significantly reduce the deviation to rotational angiography-based reconstructions (2.7 ± 0.6 mm). All PVs were isolated successfully. Intraprocedural 3D reconstruction of LA and PVs for ablation of AF is feasible based on both rotational angiography and ICE. LA reconstructions based on rotational angiography can accurately be registered using 3D ICE shells. Additional EAM does not enhance accuracy. Therefore, registration of rotational angiography-based 3D reconstructions by 3D reconstructions from ICE seems to be an alternative technique to support AF ablation.

ABSTRACT: Understanding the internal discontinuities, joints, and fissures within rock samples is crucial across multiple engineering fields, including geotechnical engineering and energy exploration. Computed tomography (CT) technology, with its non-destructive and high-resolution capabilities, has become indispensable for studying rock internal structures, overcoming the limitations of traditional methods such as mercury intrusion porosimetry, scanning electron microscopy, and nuclear magnetic resonance. This paper reviews the recent progress in the application of CT for three-dimensional (3D) reconstruction in rock mechanics. The CT technology's operational principles, encompassing X-ray penetration, signal conversion by detectors, and computer-aided reconstruction, are outlined. The discussion focuses on critical steps like image preprocessing, threshold segmentation, and 3D reconstruction, underscoring the selection of appropriate segmentation thresholds for precision. The integration of CT with laboratory investigations of rock permeability and numerical simulations is also explored. Despite advancements, challenges persist in aligning sample size with scanning resolution, threshold determination, and the development of 3D reconstruction algorithms. Future research should consider applying CT in geological CO2 utilization and storage and merging CT with other analytical techniques to broaden its scope and enhance geological research methods. 1. INTRODUCTION The mechanical properties, damages and seepage characteristics of rocks are critical research areas in fields such as oil and gas extraction, geology, geotechnical engineering and coal mining. Currently, most studies on these characteristics are based on basic assumptions that the spatial distribution of rock structures and physical-mechanical properties is homogeneous, layer-wise homogeneous or artificially given as statistically non-homogeneous distributions(Yue, 2022; Wang et al.,2021). However, rocks are composed of different mineral particles bonded or embedded together, and the prolonged sedimentation and geological processes lead to numerous discontinuous and irregular joints, fractures, and sedimentary interfaces within the rocks. Research into the heterogeneous and discontinuous characteristics of rock mechanics must first obtain the heterogeneous and discontinuous structure inside the rocks. With the advancement and development of testing equipment, as well as the requirements for the precision and imaging methods of pore and fracture observations, techniques such as mercury intrusion porosimetry (MIP) (Turturro et al.,2022), scanning electron microscopy (SEM) (Ma et al.,2022), nuclear magnetic resonance (NMR) (Cai et al.,2018), and X-ray diffraction (XRD) (Zhang et al.,2023) have gradually been applied to pore characterization studies, as detailed in Table 1. MIP is a destructive experiment and tends to underestimate the content of large pores due to its limitation on the maximum pore radius it can measure (Tang et al.,2021; Chu et al.,2022; Zhu et al.,2016). The pressure measured reflects the diameter of the pore entrance rather than the pore itself. SEM can observe the mineral occurrence form, crystal form, surface morphology, and composition, but it requires pre-treatments like gold coating and sectioning, and the observation range is very small, limiting the structural analysis to a small sample area, making it difficult to provide detailed information on the porosity and connectivity of large mineral bodies (Dehestani et al.,2020;Zhang et al.,2014;Du et al.2019). NMR, as a non-destructive testing method, is widely used to characterize pore structures with high measurement accuracy, but it is challenging to reconstruct the 3D pore structure and to obtain further information on other minerals in coal-rock bodies (Luo et al.,2022;Zhao et al.,2019).

Three-dimensional (3D) reconstruction is necessary for visualizing complex anatomy and supporting clinical decision-making in radiology. However, traditional techniques often struggle with limitations in scalability, speed, and reproducibility. The recent emergence of artificial intelligence (AI) has enabled a new generation of reconstruction tools that offer greater automation and new clinical capabilities. Motivated by the demand for efficient imaging, researchers have applied deep learning to overcome longstanding barriers, with impacts spanning diagnosis, surgical planning, and disease monitoring. This review included peer-reviewed studies published within the last 10 years, focusing exclusively on adult human imaging published in the English language, as anatomical development, imaging protocols, and clinical decision pathways differ significantly in pediatric populations. While this improved applicability to adult radiology, it limited insight into emerging pediatric and preclinical research. Searches focused on AI-driven 3D reconstruction across different radiologic modalities. Articles were selected based on the following predefined inclusion criteria: adult human participants, AI-based 3D reconstruction, clinical validation, and relevance to radiologic practice. Studies including pediatric or animal subjects, preclinical-only experimentation, non-English-language text, or without applied clinical evaluation were excluded. Our results showed that AI has improved the accuracy, speed, and clinical utility of 3D reconstruction in multiple specialties. Deep learning models such as U-Net, V-Net, DenseVNet, and generative adversarial networks have achieved high segmentation accuracy, often reporting Dice scores >0.90. These models have also been used for tumor detection, surgical planning, and reducing radiation exposure. However, challenges such as high computational requirements, lack of standardized datasets, limited real-world validation, and ethical concerns remain. In conclusion, 3D reconstruction is transforming radiology with more accurate patient-specific images for improved clinical decision-making. While it is rapidly being integrated into practice, these technologies still have limitations that need to be addressed. Nonetheless, with improved and ongoing innovation, AI has the potential to become a catalyst for precise imaging and patient care.