Objective To introduce the recent advances of the application of computer technology in tissue engineering. Methods The recent original articlesrelated to computer technology, medical image technology, computer-aided design, the advanced manufacture technology were summarized and systematically analyzed.Results Computer-aided tissue engineering is a new fieldon tissue engineering. It is the future direction of tissue engineering study. This article reviews recent development of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computeraided design, computer-aided manufacturing, rapid prototyping， RP manufacturing of tissue engineering scaffolds and computeraided implantation.Conclusion Computer-aided tissue engineering can be used in scaffolds design and fabrication, computer-aided artificial tissue implantation. It is a new field on tissue engineering.
ObjectiveTo explore potential value of three-dimensional reconstruction technique for preoperative evaluation of hepatic alveolar echinococcosis. MethodsTwenty-one cases of hepatic alveolar echinococcosis proved by postoperative pathological examination in Affiliated Hospital of Qinghai University from October 2013 to March 2014 were analyzed retrospectively. The three periods of patients’ liver dynamic thin layerCTscan images were collected and imported in three-dimensional reconstruction software by DICOM format. The volume of the virtual resected liver tissue was calculated by software, and then was compared with the actual resected liver tissue volume. ResultsThe resected liver volume was (761.94±505.77) mL and (756.19±501.78) mL in the virtual surgery and in the veritable surgery, respectively. The proportion of resected liver in the total liver was (39.27±18.75)% and (38.95±16.99)% in the virtual surgery and in the veritable surgery, respectively. The resected liver volume had no significant difference between the virtual surgery and veritable surgery (P>0.05), which a positive relation (r=0.989, P<0.001). ConclusionThe limited preliminary data in this study show that three-dimensional reconstruction technique and virtual planning system for surgery could accurately guide resection of lesion and provide preoperative guidance of accurate liver resection for hepatic alveolar echinococcosis.
Objective To employ spinal virtual surgery system (SVSS) for preoperative planning of thoracolumbar pedicle screw fixation, and to establ ish the measurement method for pedicle screw-related parameters. Methods Eight thoracicand lumbar spine specimens (T11-L3) were selected. First of all, SVSS was used for the preoperative planning of pedicle screw and the parameters of both sides of pedicle were measured in every vertebral segment, including angle of axial view (Aa), angle of sagittal view (As), x-direction entrance (XE), total pedicle length of axial view (TLa), total pedicle length of sagittal view (TLs), pedicle height (PH), pedicle width (PW), and pedicle spongy width (PSW). Then the corresponding parameters of the right and left pedicle screws of the specimens were measured actually. Finally, its accuracy was verified by comparing the data by virtual measurement and actual measurement. Results There was no significant difference in the parameters of virtual measurement (Aa, As, TLa, TLs, XE, PW, PSW, and PH) and actual measurement (Aa, As, TLa, XE, PW, PSW, and PH) between the right and left sides (P gt; 0.05). Except XE of the L3 vertebral segment and PSW of T11 and T12 vertebral segments (P lt; 0.05), the differences in other parameters of other segments were not significant (P gt; 0.05). Conclusion After statistical analysis and comparison, the feasibil ity of preoperative planning of thoracolumbar pedicle screw fixation and the accuracy of the measurement of the SVSS is verified.
Objective To study digitize design of custom-made radial head prosthesis and to verify its matching precision by the surgery of preoperative three-dimensional (3-D) virtual replacement. Methods Six healthy adult volunteers (3 males and 3 females, aged 25-55 years with an average of 33 years) received slice scan of bilateral elbow by Speed Light 16-slice spiral CT. The CT Dicom data were imported into Mimics 10.0 software individually for 3-D reconstruction image, and the left proximal radial 3-D image was extracted, the mirror of the image was generated and it was split into 2 pieces: the head and the neck. The internal diameter and the length of the radial neck were obtained by Mimics 10.0 software measurement tools. In Geomagic Studio 12 software, the radial head was simulated to cover the cartilage surface (1 mm thickness) and generated to an entity. In UG NX 8.0 software, the stem of prosthesis was designed according to the parameters above and assembled head entity. Each custom-made prosthesis was performed and verified its matching precision by the surgery of preoperative 3-D virtual replacement. Results Comparing the morphology of 6 digitize custom-made prostheses with ipsilateral radial heads by the 3-D virtual surgery, the error was less than 1 mm. The radial head prosthesis design on basis of the contralateral anatomy was verified excellent matching. Conclusion The 3-D virtual surgery test and the digitized custom-made radial head prosthesis will be available for clinical accurate replacement.
Objective To explore the histochemical staining for distinguishing and local izing nerve fibers and fascicles at histological level in three-dimensional reconstruction of peri pheral nerves. Methods The right median nerve was harvested from one fresh cadaver and embedded in OCT compound. The sample was serially horizontally sl iced with 6 μm thickness. All sections were stained with Karnovsky-Roots method (group A, n=30) firstly and then stained with toluidine blue (group B, =28) and Ponceau 2R (group C, n=21) in proper sequence. The results of each step were taken photos (× 100). After successfully stitching, the two-dimensional panorama images were compared, including texture feature, the number and aver gray level of area showing acetylchol inesterase (AchE) activity, and result of auto microscopic medical image segmentation. Results In groups A, B, and C, the number of AchE-positive area was (21.63 ± 4.06)× 102, (20.64 ± 3.51)× 102, and (20.54 ± 5.71)× 102, respectively, showing no significant difference among 3 groups (F=0.64, P=0.54); the mean gray level was (1.41 ± 0.06)× 102, (1.10 ± 0.05)× 102, and (1.14 ± 0.07)× 102, respectively, showing significant differences between group A and groups B and C (P lt; 0.001). In the image of group A, only AchE-positive area was stained; in the image of group B, myelin sheath was obscure; and in the image of group C, axons and myelin sheath could be indentified, the character of nerve fibers could be distinguished clearly and accurately, and the image segmentation of fascicles could be achieved easier than other 2 images. Conclusion The image of Karnovsky-Roots-toluidine blue-Ponceau 2R staining has no effect on the AchE-positive area in the image of Karnovsky-Roots staining and shows better texture feature. This improved histochemical process may provide ideal image for the three-dimensional reconstruction of peri pheral nerves.
Reconstructing three-dimensional (3D) models from two-dimensional (2D) images is necessary for preoperative planning and the customization of joint prostheses. However, the traditional statistical modeling reconstruction shows a low accuracy due to limited 3D characteristics and information loss. In this study, we proposed a new method to reconstruct the 3D models of femoral images by combining a statistical shape model with Laplacian surface deformation, which greatly improved the accuracy of the reconstruction. In this method, a Laplace operator was introduced to represent the 3D model derived from the statistical shape model. By coordinate transformations in the Laplacian system, novel skeletal features were established and the model was accurately aligned with its 2D image. Finally, 50 femoral models were utilized to verify the effectiveness of this method. The results indicated that the precision of the method was improved by 16.8%–25.9% compared with the traditional statistical shape model reconstruction. Therefore, the method we proposed allows a more accurate 3D bone reconstruction, which facilitates the development of personalized prosthesis design, precise positioning, and quick biomechanical analysis.
Objective To evaluate the accuracy of the related parameters measured by spinal virtual surgery system (SVSS) three-dimensional (3D) techniques by comparing with the parameters measured by multi-spiral CT (MSCT) workstation. Methods Seven vertebrae specimens of adult men were scanned with MSCT, and the messages were sent toMSCT workstation and SVSS. The 3D image of spine was reconstructed by using volume rendering and multi-planar reformation; based on the parameter requirement of lower cervical pedicle fixation, 10 related parameters were measured. Then SPSS11.0 analyzer software was used to analyze the parameters measured by 2 systems. Between June 2009 and March 2010, 6 patients who received screw insertion in lower cervical spines were given MSCT scanning, then the messages were sent to SVSS 3D reconstruction to evaluate the situation and to collect the parameters of pedicle screw insertion. Results SVSS measurement showed that 1 pedicle was clausura (C3) and the diameters of 4 pedicles in coronal view were lee than 3 mm (C4 in 1, C5 in 2, C6 in 1), which did not fit for screw insertion; the results were similar to those by MSCT measurement. A total of 66 lower cervical pedicle were measured successfully. Significant differences were found in 14 parameters as follows between 2 systems (P lt; 0.05): the left pedicle height of C3, the both sides pedicle width of C4, the right pedicle spongy width of C4, the left X-direction entrance of C6, the both sides Y-direction entrance of C3, total pedicle length of sagittal view in both sides pedicle of C3 and the left pedicle of C5, total pedicle length of axial view in C3 pedicles, the left pedicle of C5, and the right pedicle of C6. There was no significantdifference in the other parameters (P gt; 0.05). In 6 cl inical cases, 34 screws were inserted, the postoperative MSCT scanning showed that 30 screws were placed successfully. The rate of accuracy was 88.24%. According to the Richter’s perforation classification, perforation at grade I and at grade II occurred in 2 cases (5.88%), respectively. Conclusion The accuracy of the parameters measured by SVSS is similar to that by MSCT.
Objective To assess the value of precise hepatectomy in treatment of primary hepatocellular carcinoma. Methods Three-dimensional (3D) models from MR image were reconstructed by 3D-Doctor software in 32 patients with primary hepatocellular carcinoma scheduled for liver resection between July 2007 and Sept 2009. From these 3D models, the vena cava, portal vein, hepatic vein, and short hepatic vein images were reconstructed, total liver volume, tumor volume, functional liver volume and ratio of functional liver volume to standard liver volume (SFLVR) were calculated. The patients were followed-up for 1-27 months, with an average of 12 months. Results The anatomic detail of liver veins and its relationship with the tumor could be displayed clearly in liver 3D models. By the 3D models, total liver volume was calculated as （1 353±419）ml, tumor volume as （287±248） ml, functional liver volume as （830±289） ml, and SFLVR as （71±22）%. Of 32 patients with hepatocellular carcinoma, right hemihepatectomy was performed in 8 cases, left hemihepatectomy in 2, and segmental or limited resection in 22. All operations were completed successfully. Postoperative complications included pulmonary infection in 1 case, bile leak in 1, moderate ascites (500-3 000 ml) in 8, and massive ascites (gt;3 000 ml) in 2 including one patient developed hepatic failure. Six and 12-month survival rates were 100% and 87%. Three, 6, and 12-month disease-free survival rates were 78%, 72%, and 72%. Conclusions Precise hepatectomy technique provides an accurate picture of liver veins anatomy and its relationship with the tumor， and allows the procedure to be simulated preoperatively for adequate and safe hepatectomy.
ObjectiveTo evaluate the application value of three-dimensional (3D) reconstruction in preoperative surgical diagnosis of new classification criteria for lung adenocarcinoma, which is helpful to develop a deep learning model of artificial intelligence in the auxiliary diagnosis and treatment of lung cancer.MethodsThe clinical data of 173 patients with ground-glass lung nodules with a diameter of ≤2 cm, who were admitted from October 2018 to June 2020 in our hospital were retrospectively analyzed. Among them, 55 were males and 118 were females with a median age of 61 (28-82) years. Pulmonary nodules in different parts of the same patient were treated as independent events, and a total of 181 subjects were included. According to the new classification criteria of pathological types, they were divided into pre-invasive lesions (atypical adenomatous hyperplasia and and adenocarcinoma in situ), minimally invasive adenocarcinoma and invasive adenocarcinoma. The relationship between 3D reconstruction parameters and different pathological subtypes of lung adenocarcinoma, and their diagnostic values were analyzed by multiplanar reconstruction and volume reconstruction techniques.ResultsIn different pathological types of lung adenocarcinoma, the diameter of lung nodules (P<0.001), average CT value (P<0.001), consolidation/tumor ratio (CTR, P<0.001), type of nodules (P<0.001), nodular morphology (P<0.001), pleural indenlation sign (P<0.001), air bronchogram sign (P=0.010), vascular access inside the nodule (P=0.005), TNM staging (P<0.001) were significantly different, while nodule growth sites were not (P=0.054). At the same time, it was also found that with the increased invasiveness of different pathological subtypes of lung adenocarcinoma, the proportion of dominant signs of each group gradually increased. Meanwhile, nodule diameter and the average CT value or CTR were independent risk factors for malignant degree of lung adenocarcinoma.ConclusionImaging signs of lung adenocarcinoma in 3D reconstruction, including nodule diameter, the average CT value, CTR, shape, type, vascular access conditions, air bronchogram sign, pleural indenlation sign, play an important role in the diagnosis of lung adenocarcinoma subtype and can provide guidance for personalized therapy to patients in clinics.
ObjectiveTo evaluate the safety and application value of three-dimensional reconstruction for localization of pulmonary nodules in thoracoscopic lung wedge resection.MethodsThe clinical data of 96 patients undergoing thoracoscopic lung wedge resection in our hospital from January 2019 to August 2020 were retrospectively reviewed and analyzed, including 30 males and 66 females with an average age of 57.62±12.13 years. The patients were divided into two groups, including a three-dimensional reconstruction guided group (n=45) and a CT guided Hook-wire group (n=51). The perioperative data of the two groups were compared.ResultsAll operations were performed successfully. There was no statistically significant difference between the two groups in the failure rate of localization (4.44% vs. 5.88%, P=0.633), operation time [15 (12, 19) min vs. 15 (13, 17) min, P=0.956], blood loss [16 (10, 20) mL vs. 15 (10, 19) mL, P=0.348], chest tube placement time [2 (2, 2) d vs. 2 (2, 2) d, P=0.841], resection margin width [2 (2, 2) cm vs. 2 (2, 2) cm, P=0.272] or TNM stage (P=0.158). The complications of CT guided Hook-wire group included pneumothorax in 2 patients, hemothorax in 2 patients and dislodgement in 4 patients. There was no complication related to puncture localization in the three-dimensional reconstruction guided group.ConclusionBased on three-dimensional reconstruction, the pulmonary nodule is accurately located. The complication rate is low, and it has good clinical application value.