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        find Keyword "three-dimensional reconstruction" 39 results
        • Numerical Simulation of Heat Transfer in the Human Anterior Chamber at Different Corneal Temperatures

          A three-dimensional (3D) model of human anterior chamber is reconstructed to explore the effect of different corneal temperatures on the heat transfer in the chamber. Based on the optical coherence tomography imaging of the volunteers with normal anterior chamber, a 3D anterior chamber model was reconstructed by the method of UG parametric design. Numerical simulation of heat transfer and aqueous humor flow in the whole anterior chamber were analyzed by the finite volume methods at different corneal temperatures. The results showed that different corneal temperatures had obvious influence on the temperature distribution and the aqueous flow in the anterior chamber. The temperature distribution is linear and axial symmetrical around the pupillary axis. As the temperature difference increases, the symmetry becomes poorer. Aqueous floated along the warm side and sank along the cool side which forms a vortexing flow. Its velocity increased with the addition of temperature difference. Heat fluxes of cornea, lens andiris were mainly affected by the aqueous velocity. The higher the velocity, the bigger more absolute value of the above-mentioned heat fluxes became. It is practicable to perform the numerical simulation of anterior chamber by the optical coherence tomography imaging. The results are useful for studying the important effect of corneal temperature on the heat transfer and aqueous humor dynamics in the anterior chamber.

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        • Advances in the application of AI-assisted 3D reconstruction in thoracoscopic pulmonary nodule resection surgery

          In thoracoscopic pulmonary nodule resection surgery, precise preoperative planning is crucial. Artificial intelligence (AI)-assisted three-dimensional (3D) reconstruction technologies have shown great potential in this area. AI-assisted 3D reconstruction technologies can provide accurate, personalized models of the pulmonary vasculature and bronchial anatomy, assisting surgeons in detailed surgical planning and thus enhancing the precision and safety of surgeries. This article reviews the application progress of AI-assisted 3D reconstruction technologies in pulmonary nodule surgery, including their applications in preoperative diagnosis, surgical planning, and intraoperative navigation, as well as the advancements in AI-assisted 3D reconstruction technologies. It analyzes the technical features of all kinds of 3D reconstruction methods, their clinical applications, and the challenges they face.

          Release date:2025-01-21 11:07 Export PDF Favorites Scan
        • Puncture positioning versus free-of-puncture positioning under three-dimensional navigation in the anatomical segmentectomy for pulmonary nodules: A retrospective cohort study

          ObjectiveTo explore the feasibility and clinical value of free-of-puncture positioning in three-dimension-guided anatomical segmentectomy for ground-glass nodule (GGN) compared with percutaneous positioning.MethodsClinical data of 268 enrolled patients undergoing anatomical pulmonary segmentectomy from October 2018 to June 2019 were retrospectively collected, including 75 males and 193 females with an average age of 56.55±12.10 years. The patients were divided into two groups, including a percutaneous positioning group (n=89) and a free-of-puncture positioning group (n=179). Perioperative data of the two groups were compared.ResultsThe average CT scan times of the percutaneous positioning group was 3.01±0.98 times, and the numerical rating scale (NRS) score of puncture pain was 3.98±1.61 points. Pulmonary compression pneumothorax (≥30%) occurred in 7 (7.87%) patients and intercostal vascular hemorrhage occurred in 8 (8.99%) patients after puncture. Lung nodules were successfully found and removed in both groups. There was no statistically significant difference between the two groups in the location of nodules (P=0.466), operation time (151.83±39.23 min vs. 154.35±33.19 min, P=0.585), margin width (2.07±0.35 cm vs. 1.98±0.28 cm, P=0.750), or the number of excised subsegments (2.83±1.13 vs. 2.73±1.16, P=0.530).ConclusionAnatomical segmentectomy with three-dimensional navigation avoids the adverse consequences of puncture, which has the same clinical efficacy and meets the requirements of oncology compared with percutaneous positioning. The free-of-puncture positioning method can be used for GGN located in the central region of pulmonary segment/subsegment or adjacent to intersegment veins instead of percutaneous positioning.

          Release date:2021-10-28 04:13 Export PDF Favorites Scan
        • Applied anatomy research of the uncovertebral joint for design of uncovertebral joint fusion cage

          ObjectiveTo measure anatomical parameters related to cervical uncovertebral joint and provide data support for the design of uncovertebral joint fusion cage.MethodsAccording to the inclusion and exclusion criteria, raw DICOM data of cervical CT scan in 60 patients (30 males and 30 females, aged 39-60 years) were obtained, then the three-dimensional cervical spine model was reconstructed for anatomical measurement by using the Mimics19.0 software. The height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region were measured bilaterally from C3 to C7. The anterior and posterior distances between the uncinate processes were measured from C3 to C7. The height of the uncovertebral joint space, the central height of the intervertebral disc space, and the depth of the intervertebral disc space were also measured from C2, 3 to C6, 7. The mean, standard deviation, maximum, and minimum were calculated by using the SPSS22.0 statistical software for the design of uncovertebral joint fusion cage.ResultsThe height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region of C3-C7 and the height of the uncovertebral joint space of C2, 3-C6, 7 showed no significant difference between two sides (P>0.05). The height of the uncovertebral joint space also had no significant difference between females and males (P>0.05). The anterior distances between the uncinate processes of C3-C7 were significantly larger than the posterior distances between the uncinate processes (P<0.05), the uncovertebral joint presented a posterior cohesive shape. The central height of the intervertebral disc space in male group was slightly higher than that in female group, and the differences were significant (P<0.05) at C2, 3 and C5, 6; the depth of the intervertebral disc space in male group was significantly higher than that in female group (P<0.05). The central height of the intervertebral disc space was (4.94±0.49) mm (range, 3.81-5.90 mm), the depth of the intervertebral disc space was (15.78±1.23) mm (range, 12.94-18.85 mm), the anterior and posterior distances between the uncinate processes were (17.19±2.39) mm (range, 13.39-24.63 mm) and (10.84±2.12) mm (range, 7.19-16.64 mm), respectively. According to the results of the anatomical research, the height of the uncovertebral joint fusion cage was designed as 5, 6, 7, and 8 mm; the depth of the uncovertebral joint fusion cage was designed as 12, 13, 14, 15, and 16 mm; the width of the uncovertebral joint fusion cage was designed as 14-18 mm; and the two wings are designed as arc-shape with 2 and 3 mm in width.ConclusionThere are certain differences in the anatomical parameters of the uncovertebral joint between different segments. The uncovertebral joint fusion cage that designed based on the results of anatomical research is suitable for most patients.

          Release date:2019-12-23 09:44 Export PDF Favorites Scan
        • Study on the evaluation of glenoid bone defects by MRI three-dimensional reconstruction

          Objective To investigate the feasibility of MRI three-dimensional (3D) reconstruction model in quantifying glenoid bone defect by comparing with CT 3D reconstruction model measurement. Methods Forty patients with shoulder anterior dislocation who met the selection criteria between December 2021 and December 2022 were admitted as study participants. There were 34 males and 6 females with an average age of 24.8 years (range, 19-32 years). The injury caused by sports injury in 29 cases and collision injury in 6 cases, and 5 cases had no obvious inducement. The time from injury to admission ranged from 4 to 72 months (mean, 28.5 months). CT and MRI were performed on the patients’ shoulder joints, and a semi-automatic segmentation of the images was done with 3D slicer software to construct a glenoid model. The length of the glenoid bone defect was measured on the models by 2 physicians. The intra-group correlation coefficient (ICC) was used to evaluate the consistency between the 2 physicians, and Bland-Altman plots were constructed to evaluate the consistency between the 2 methods. Results The length of the glenoid bone defects measured on MRI 3D reconstruction model was (3.83±1.36) mm/4.00 (0.58, 6.13) mm for physician 1 and (3.91±1.20) mm/3.86 (1.39, 5.96) mm for physician 2. The length of the glenoid bone defects measured on CT 3D reconstruction model was (3.81±1.38) mm/3.80 (0.60, 6.02) mm for physician 1 and (3.99±1.19) mm/4.00 (1.68, 6.38) mm for physician 2. ICC and Bland-Altman plot analysis showed good consistency. The ICC between the 2 physicians based on MRI and CT 3D reconstruction model measurements were 0.73 [95%CI (0.54, 0.85)] and 0.80 [95%CI (0.65, 0.89)], respectively. The 95%CI of the difference between the two measurements of physicians 1 and 2 were (–0.46, 0.49) and (–0.68, 0.53), respectively. Conclusion The measurement of glenoid bone defect based on MRI 3D reconstruction model is consistent with that based on CT 3D reconstruction model. MRI can be used instead of CT to measure glenoid bone defects in clinic, and the soft tissue of shoulder joint can be observed comprehensively while reducing radiation.

          Release date:2023-05-11 04:44 Export PDF Favorites Scan
        • Three-dimensional morphological study of the effect of false acetabulum on the femoral structure in Crowe type Ⅳ developmental dysplasia of the hip

          ObjectiveTo explore the effect of false acetabulum on the development and anatomical morphology of proximal femur in Crowe type Ⅳ developmental dysplasia of the hip (DDH), providing a theoretical basis for the development of femoral reconstruction strategy and prosthesis selection for total hip arthroplasty. Methods The medical records of 47 patients (54 hips) with Crowe type Ⅳ DDH between February 2008 and March 2020 were retrospectively analyzed, of which 21 patients (26 hips) were Crowe type Ⅳa (type Ⅳa group) and 26 patients (28 hips) were Crowe type Ⅳb (type Ⅳb group). There was no significant difference in general data such as gender, age, height, weight, body mass index, and side between the two groups (P>0.05), which were comparable. The height of femoral head dislocation, the height of pelvis, and the proportion of dislocation were measured based on preoperative anteroposterior pelvic X-ray film. Based on the preoperative femoral CT scan data, the anatomical parameters of the femur and femoral medullary cavity were measured after three-dimensional reconstruction using Mimics19.0 software to calculate the canal fare index; and the femoral medullary cavity parameters were matched with the modular S-ROM prosthesis parameters. ResultsThe results of X-ray film measurement showed that the height of femoral head dislocation and the proportion of dislocation in type Ⅳa group were significantly higher than those in type Ⅳb group (P<0.05). There was no significant difference in the height of pelvis between the two groups (P>0.05). The results of CT three-dimensional reconstruction measurements showed that compared with the type Ⅳb group, the type Ⅳa group had less isthmus height, smaller femoral head, shorter femoral neck, narrower neck-shaft angle, increased anteversion angle, and higher greater trochanter, and the differences were significant (P<0.05). There was no significant difference in the height of femoral head, femoral offset, and height difference between greater trochanter and femoral head between the two groups (P>0.05). There was no significant difference in the mediolateral width (ML), anteroposterior width (AP), and diameter of the isthmus (Ci level) and the AP of the medullary cavity in the plane 40 mm distal to the most prominent point on the medial side of the lesser trochanter (C–40 level) (P>0.05), and the size of medullary cavity was significantly smaller in type Ⅳa group than in type Ⅳb group at the other levels (P<0.05). Compared with the type Ⅳb group, the difference between the outer diameter of the prosthetic sleeve and the diameter of the medullary cavity fitting circle in the plane where the center of femoral head rotation was located from the medial most prominent point of the lesser trochanter (C0 level) in type Ⅳa group was smaller, and the proportion of negative values was greater (P<0.05). The difference between the longest diameter of the prosthetic sleeve triangle and the ML of the medullary cavity in the plane 10 mm proximal to the most prominent point on the medial side of the lesser trochanter (C+10 level) in type Ⅳa group was smaller, and the proportion of negative values was greater (P<0.05). ConclusionFalse acetabulum has a significant impact on the morphology of the proximal femur and medullary cavity in patients with Crowe type Ⅳ DDH, and the application of three-dimensional reconstruction technique can accurately evaluate the femoral morphology and guide the selection of femoral prosthesis.

          Release date:2022-06-29 09:19 Export PDF Favorites Scan
        • Application of three-dimentional visualized reconstruction technology in resection of treating hepatic alveolar echinococcosis

          Objective To evaluate effects of three-dimensional (3D) visualized reconstruction technology on short-term benefits of different extent of resection in treating hepatic alveolar echinococcosis (HAE) as well as some disadvantages. Methods One hundred and fifty-two patients with HAE from January 2014 to December 2016 in the Department Liver Surgery, West China Hospital of Sichuan University were collected, there were 80 patients with ≥4 segments and 72 patients with ≤3 segments of liver resection among these patients, which were designed to 3D reconstruction group and non-3D reconstruction group according to the preference of patients. The imaging data, intraoperative and postoperative indicators were recorded and compared. Results The 3D visualized reconstructions were performed in the 79 patients with HAE, the average time of 3D visualized reconstruction was 19 min, of which 13 cases took more than 30 min and the longest reached 150 min. The preoperative predicted liver resection volume of the 79 patients underwent the 3D visualized reconstruction was (583.6±374.7) mL, the volume of intraoperative actual liver resection was (573.8±406.3) mL, the comparison of preoperative and intraoperative data indicated that both agreed reasonably well (P=0.640). Forty-one cases and 38 cases in the 80 patients with ≥4 segments and 72 patients with ≤3 segments of liverresection respectively were selected for the 3D visualized reconstruction. For the patients with ≥4 segments of liver resection, the operative time was shorter (P=0.021) and the blood loss was less (P=0.047) in the 3D reconstruction group as compared with the non-3D reconstruction group, the status of intraoperative blood transfusion had no significant difference between the 3D reconstruction group and the non-3D reconstruction group (P=0.766). For the patients with ≤3 segments of liver resection, the operative time, the blood loss, and the status of intraoperative blood transfusion had no significant differences between the 3D reconstruction group and the non-3D reconstruction group (P>0.05). For the patients with ≥4 segments or ≤3 segments of liver resection, the laboratory examination results within postoperative 3 d, complications within postoperative 90 d, and the postoperative hospitalization time had no significant differences between the 3D reconstruction group and the non-3D reconstruction group (P>0.05). Conclusion 3D visualized reconstruction technology contributes to patients with HAE ≥4 segments of liver resection, it could reduce intraoperative blood loss and shorten operation time, but it displays no remarkable benefits for ≤3 segments of liver resection.

          Release date:2018-05-14 04:18 Export PDF Favorites Scan
        • Establishment of micro-vessels model of cross-boundary perforator flap in rat via digital technology

          Objective To investigate the feasibility and application value of digital technology in establishing the micro-vessels model of cross-boundary perforator flap in rat. Methods Twenty 8-week-old female Sprague Dawley rats, weighing 280-300 g, were used to established micro-vessels model. The cross-boundary perforator flaps of 10 cm×3 cm in size were prepared at the dorsum of 20 rats; then the flaps were suturedin situ. Ten rats were randomly picked up at 3 and 7 days after operation in order to observe the necrosis of flap and measure the percentage of flap necrosis area; the lead-oxide gelatin solution was used for vessels perfusion; flaps were harvested and three-dimensional reconstruction of micro-vessel was performed after micro-CT scanning. Vascular volume and total length were measured via Matlable 7.0 software. Results The percentage of flap necrosis area at 3 days after operation was 19.08%±3.64%, which was significantly lower than that at 7 days (39.76%±3.76%;t=10.361, P=0.029). Three-dimensional reconstruction via the micro-CT clearly showed the morphological alteration of micro-vessel of the flap. At 3 days after operation, the vascular volume of the flap was (1 240.23±89.71) mm3 and the total length was (245.94±29.38) mm. At 7 days after operation, the vascular volume of the flap was (1 036.96±88.97) mm3 and the total length was (143.20±30.28) mm. There were significant differences in the vascular volume and the total length between different time points (t=5.088, P=0.000; t=7.701, P=0.000). Conclusion The digital technology can be applied to visually observe and objectively evaluate the morphological alteration of the micro-vessels of the flap, and provide technical support for the study of vascular model of flap.

          Release date:2017-12-11 12:15 Export PDF Favorites Scan
        • Three-dimensional reconstruction of carp brain tissue and brain electrodes for biological control

          In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.

          Release date:2020-12-14 05:08 Export PDF Favorites Scan
        • ANATOMIC STUDY ON HOOK OF HAMATE BONE

          Objective To study the hook of hamate bone by anatomy and iconography methods in order to provide information for the cl inical treatment of injuries to the hook of hamate bone and the deep branch of ulnar nerve. Methods Fifty-two upper l imb specimens of adult corpses contributed voluntarily were collected, including 40 antisepticized old specimens and 12 fresh ones. The hook of hamate bone and its adjacent structure were observed. Twentyfour upper l imbs selected randomly from specimens of corpses and 24 upper l imbs from 12 healthy adults were investigated by computed tomography (CT) three-dimensional reconstruction, and then related data were measured. The measurement results of24 specimens were analyzed statistically. Results The hook of hamate bone is an important component of ulnar carpal canal and carpal canal, and the deep branch of ulnar nerve is located closely in the inner front of the hook of hamate bone. The flexor tendons of the forth and the l ittle fingers are in the innermost side, closely l ie next to the outside of the hook of hamate bone. The hamate bone located between the capitate bone and the three-cornered bone with wedge-shaped. The medial-, lateral-, and front-sides are all facies articularis. The hook of hamate bone has an approximate shape of a flat plate. The position migrated from the body of the hamate bone, the middle of the hook and the enlargement of the top of the hook were given the names of “the basis of the hook”, “the waist of the hook”, and “the coronal of the hook”, respectively. The short path of the basement are all longer than the short path of the waist. The long path of the top of the hook is the maximum length diameter of the hook of hamate bone, and is longer than the long path of the basement and the long path of the waist. The iconography shape and trait of the hook of hamate bone is similar to the anatomy result. There were no statistically significant differences (P gt; 0.05) between two methods in the seven parameters as follows: the long path of the basement of the hook, the short path of the basement of the hook, the long path of the waist of thehook, the short path of the waist of the hook, the long path of the top of the hook, the height of the hook, of hamate bone, and the distance between the top and the waist of the hook. Conclusion The hook of hamate bone can be divided into three parts: the coronal part, the waist part, and the basal part; fracture of the hamate bone can be divided into fracture of the body, fracture of the hook, and fracture of the body and the hook. Facture of the hook of hamate bone or fracture unnion can easily result in injure of the deep branch of ulnar nerve and the flexor tendons of the forth and the l ittle fingers. The measurement results of CT threedimensional reconstruction can be used as reference value directly in cl inical treatments.

          Release date:2016-08-31 05:47 Export PDF Favorites Scan
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          2. 射丝袜