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        find Keyword "CT" 549 results
        • STUDY ON ACCURACY OF VIRTUAL SURGICAL PLANNING IN FREE FIBULA MANDIBULAR RECONSTRUCTION BY USING SurgiCase SOFTWARE

          Objective To evaluate the directional significance of SurgiCase software in free fibula mandibular reconstruction. Methods Between September 2010 and March 2012, 10 patients with mandibular defect underwent free fibula mandibular reconstruction. There were 7 males and 3 females, with an age range of 19-43 years (mean, 27 years). The extent of lesions was 7 cm × 5 cm to 16 cm × 8 cm. In each case, three-dimensional spiral CT scan of the maxilla, mandible, and fibula was obtained before surgery. The CT data were imported into the SurgiCase software and the virtual surgery planning was performed. After that, the mandibular rapid prototyping was made according to customized design. The reconstruction surgery was then carried out using these preoperative data. During actual surgery, the extent of mandibular defect was from 6 cm × 3 cm to 16 cm × 5 cm; the length of fibula which was used to reconstruct mandible was 6-17 cm; and the area of flap was from 6 cm × 5 cm to 16 cm × 6 cm. Results Preoperative data could not be applied because the intraoperative size of tumor was larger than preoperative design in 1 case of mandibular ameloblastoma, and the fibula was shaped according to the actual osteotomy location; operations were performed successfully according to preoperative design in the other 9 patients. The operation time was 5-7 hours (mean, 6 hours). Primary healing of incision was obtained, without early complications. Ten patients were followed up 1 year. At last follow-up, 8 patients were satisfactory with the appearance and 2 patients complained with unsatisfied wide facial pattern. The panoramic radiograghs showed good bone healing. The range of mouth opening was 2.5-3.5 cm. Conclusion SurgiCase software can provide precise data for free fibula mandibular reconstruction during surgery. It can be applied widely in clinic.

          Release date:2016-08-31 04:08 Export PDF Favorites Scan
        • VASCULAR ANATOMY OF DONOR AND RECIPIENT IN LIVING KIDNEY TRANSPLANTATION

          Objective To review the vascular anatomy of the donor and the reci pient for the l iving kidney transplantation. Methods The recent l iterature about the vessels of donor and reci pient in cl inical appl ications was extensively reviewed. Results The pertinent vascular anatomy of the donor and recipient was essential for the screening of the proper candidates, surgical planning and long-term outcome. Early branching and accessory renal artery of the donor were particularly important to deciding the side of nephrectomy, surgical technique and anastomosing pattern, and their injuries were the most frequent factor of the conversion from laparoscopic to open surgery. With increase of laparoscopic nephrectomy indonors, accurate venous anatomy was paid more and more attention to because venous bleeding could also lead to conversion to open nephrectomy. Multidetector CT (MDCT) could supplant the conventional excretory urography and renal catheter angiography and could accurately depict the donors’ vessels, vascular variations. In addition, MDCT can excellently evaluate the status of donor kidney, collecting system and other pertinent anatomy details. Conclusion Accurate master of related vascular anatomy can facil iate operation plan and success of operation and can contribute to the rapid development of living donor kidney transplantation. MDCT has become the choice of preoperative one-stop image assessment for living renal donors.

          Release date:2016-09-01 09:08 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
        • COMBINATION SURFACE SHADED DISPLAY WITH MULTIPLANAR RECONSTRUCTION IN THE EVALUATIONOF ACETABULAR MORPHOLOGIES IN PATIENTS WITH DEVELOPMENTAL DYSPLASIA OF THE HIP BEFORETOTAL HIP ARTHROPLASTY

          【Abstract】 Objective To explore the methods and appl ication value of surface shaded display (SSD) and multiplanarreconstruction (MPR) in the evaluation of acetabular morphology in patients with developmental dysplasia of the hip (DDH) before total hip arthroplasty (THA). Methods From October 2003 to November 2006, 17 patients (3 males and 14 females, aging from 35 years to 61 years) with osteoarthritis secondary to DDH were scanned with spiral CT preoperatively. According to the Crowe standard, 19 dysplasia hips were classified as type I in 4 hips, type II in 9 hips, type III in 6 hips. The obtained hip CT data were developed with SSD and MPR to observe spational position and bone stock of the acetabula. Results The dislocated extent was 25%-89% in these dysplasia hips according to the Crowe method and their sharp angles all exceeded 45°. Bone defect occurred to each of the acetabula, among which it was located in anterosuperior acetabulum in 5 hips, in superolateral acetabulum in 11 hips and in posterosuperior acetabulum in 3 hips. The hip images made with MPR showed that the minimum thickness of the medial wall of acetabula ranged from 2.0 mm to 10.9 mm. Among 15 unilateral dysplasia patients, the opening difference anddepth difference between the dysplasia acetabulum and the contralateral one ranged from 2.7 mm to 19.1 mm and from 2.3 mm to 13.1 mm, respectively. Conclusion SSD and MPR of spiral CT are effective methods in evaluating acetabular morphology preoperation and contribute to intraoperative acetabular reconstruction in patients with DDH performed THA.

          Release date:2016-09-01 09:12 Export PDF Favorites Scan
        • RELIABILITY RESEARCH OF MULTI-PLANNAR REFORMATION OF MULTI-SPIRAL COMPUTERIZED TOMOGRAPHY IN MEASURING KYPHOSIS ANGLE AFTER THORACOLUMBAR FRACTURE

          Objective To study the feasibil ity and rel iabil ity of the multi-plannar reformation (MPR) of multispiral CT (MSCT) in measuring the kyphosis angle (KA) after thoracolumbar fracture. Methods From December 2007 to December 2009, 45 thoracolumbar fracture patients who underwent computed radiology (CR) and MSCT were recruited. There were 32 males and 13 females with a mean age of 48 years (range, 24-63 years), including 36 simple compression fractures and 9 burst fractures. The fracture locations were T11 in 6 cases , T12 in 11 cases, L1 in 20 cases, and L2 in 8 cases. Fracture was caused by trafffic accident in 25 cases, by fall ing from height in 12 cases, and by others in 8 cases. The imaging examination was performed after 2 hours to 7 days of injury in 22 cases and after more than 7 days in 23 cases. The KA was measured on the lateral X-ray films of CR and MPR by two observers, then the measurements were done again after three weeks. The data were statistically analyzed. Results The average KA values on CR by two observers were (20.75 ± 8.31)° and (22.49 ± 9.07)°, respectively; showing significant difference (P lt; 0.05), and the correlation was good (r=0.882, P lt; 0.05). The average KA values on MPR by two observers were (16.65 ± 8.62)° and (17.08 ± 7.88)°, respectively, showing no significant difference (P gt; 0.05), the correlation was excellent (r=0.976, P lt; 0.05). The average KA values on CR and MPR were (21.61 ± 8.43)° and (16.87 ± 8.20)°, respectively; showing significant difference (P lt; 0.05), the correlation was good (r=0.852, P lt; 0.05). Conclusion It is more feasible and rel iable in measuring the KA on MRP of MSCT than CR, but the value is larger on CR.

          Release date:2016-08-31 05:48 Export PDF Favorites Scan
        • Visualization research of three-dimensional microstructure of rabbit sciatic nerve bundles by micro-CT

          Objective To realize the visualization of three-dimensional microstructure of rabbit sciatic nerve bundles by micro-CT and three-dimensional visualization software Mimics17.0. Methods The sciatic nerve tissues from 6 New Zealand rabbits were divided into 2 groups (n=3), and the sciatic nerve tissues were stained by 1% (group A) and 5% (group B) Lugol solution respectively. After staining for 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 hours, the imaging changes of specimens were observed by light microscope and micro-CT. The clear micro-CT images were exported to the Mimics software to complete the visualization of three-dimensional microstructure of rabbit sciatic nerve according to three-dimensional reconstruction tool. Results The clear three-dimensional microstructure images could be observed in group A at 2.5 hours after staining and in group B at 1.5 hours after staining by light microscope and micro-CT. The sciatic nerve of New Zealand rabbits were divides into 3 bundles and each of them was relatively fixed. There was no obvious crossing or mergers between each bundle. The cross-sectional area of each bundle was (0.425±0.013), (0.038±0.007), and (0.242±0.026) mm2 respectively. The digital model could clearly reflect the microstructure of the sciatic nerve at all cross sections. Conclusion The internal structure of New Zealand rabbits sciatic nerve can be clearly reflected by micro-CT scanning. It provides a reliable method for establishing a nerve microstructure database with large amount specimens.

          Release date:2017-12-11 12:15 Export PDF Favorites Scan
        • Effect of natural hirudin on revascularization of ischemic skin flaps in rats by Micro-CT

          ObjectiveTo investigate the effect of natural hirudin on revascularization of ischemic skin flap in rats using Micro-CT and three-dimensional (3D) reconstruction.MethodsThirty-two Sprague Dawley rats were prepared a ischemic skin flap (8.0 cm×1.8 cm) model on the back and randomly divided into hirudin group and control group (16 rats in each group). At immediate and within 3 days after operation, the rats were treated with hypodermic injection of natural hirudin 0.3 mL (including natural hirudin 6 ATU) every day in hirudin group and the equal amount of normal saline in control group. At 6 days after operation, the survival rate of skin flap was evaluated, histological changes were observed by HE staining, and the volemia, length of blood vessels, and number of blood vessels were analyzed with Micro-CT 3D reconstruction.ResultsBoth groups of rats survived to the end of the experiment without infection. Different degrees of necrosis occurred in the distal part of the skin flaps in both groups at 6 days after operation, but the flap survival rate of the hirudin group (72.11%±8.97%) was significantly higher than that of control group (58.94%±4.02%) (t=3.280, P=0.008). Histological observation showed that the histological hierarchy of the hirudin group was clearer than that of the control group, with more microangiogenesis and less inflammatory response and inflammatory cell infiltration. Micro-CT 3D reconstruction showed that the flap vessels in the hirudin group were more and denser, and the volemia, length of blood vessels, and number of blood vessels were significantly higher than those in the control group (P<0.05).ConclusionNatural hirudin can reduce the inflammation of tissue, promote the regeneration and recanalization of blood vessels in ischemic skin flap, so as to improve the survival rate of the flap.

          Release date:2020-04-15 09:18 Export PDF Favorites Scan
        • A comparative study of color Doppler ultrasound and CT angiography for preoperative evaluation of perforator vessels in free posterior interosseous artery flap

          Objective To investigate the accuracy of color Doppler ultrasound (CDU) and CT angiography (CTA) in the preoperative evaluation of perforator vessels in free posterior interosseous artery perforator (PIAP) flaps. Methods Between January 2020 and December 2023, 19 patients with hand skin and soft tissue defects caused by trauma were admitted. There were 11 males and 8 females, with a median age of 45 years (range, 26-54 years). The interval between injury and admission was 5-11 days (mean, 7.2 days). The skin and soft tissue defects were located on the dorsum of the hand in 8 cases and on the fingers in 11 cases. The size of defect ranged from 4.0 cm×2.5 cm to 7.5 cm×3.5 cm. After locating the perforator vessels through CDU and CTA before operation, the free PIAP flaps were designed to repair hand defects, with the size of 4.5 cm×3.0 cm-7.5 cm×4.0 cm. The defects of donor sites were directly sutured. The number and diameter of perforator vessels in the posterior interosseous artery detected by CDU and CTA were compared. The differences in localization of perforator vessels using CDU and CTA and their clinical effects were also compared to calculate the accuracy and recognition rate. During follow-up, the survival of the skin flap was observed, and the Vancouver scar scale (VSS) score was used to evaluate the healing of the donor site, while the visual analogue scale (VAS) score was used to evaluate the patient’s satisfaction with the appearance of the skin flap. Results The number and the diameter of PIAP vessels was 5.8±1.2 and (0.62±0.08) mm assessed by CDU and 5.2±1.0 and (0.60±0.07) mm by CTA, showing no significant difference between the two methods (P>0.05). The number, course, and distribution of perforator vessels of the PIAP vessels observed during operation were basically consistent with those detected by preoperative CDU and CTA. Compared with intraoperative observation results, the recognition rates of dominant perforating vessels by CDU and CTA were 95.0% (18/19) and 89.5% (17/19), respectively, and the accuracy rates were 100% (19/19) and 84.2% (16/19), with no significant difference between the two methods (P>0.05). All flaps survived after operation, and all wounds and incisions at donor sites healed by first intention. All patients were followed up 6-13 months (mean, 8.2 months). At last follow-up, the skin flaps had elasticity and soft texture, with the patient satisfaction VAS score of 9.2±0.8. The donor sites had no obvious scar hyperplasia with the VSS score of 11.7±0.9. Conclusion CDU and CTA accurately identify the dominant perforator vessels and provide reliable information for vessel localization, facilitating precise flap harvesting and minimizing donor site injury. However, CDU offers superior visualization of distal end of perforator vessels in the forearm compared to CTA.

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        • The Iodine Maps Created from Dual-Source Dual-Energy CT for The Diagnosis of Pancreatic Necrosis in The Early Stage of Acute Pancreatitis

          ObjectiveTo evaluate the value of 120 kV portal venous phase images combined with iodine maps created from dual-source dual-energy CT (DECT) for the diagnosis of pancreatic necrosis in the early stage of acute pancreatitis. MethodsThis prospective study enrolled 17 patients who underwent abdominal dual-source DECT within 72 hours from the onset of acute pancreatitis. All patients had received treatment in West China Hospital from May 2014 to August 2014. Comparison of the diagnostic value of 120 kV portal venous phase images alone and 120 kV portal venous phase images combined with iodine maps created from dual-source DECT was performed. ResultsSix of the 17 patients were found the presence of pancreatic necrosis (4 patients without obvious necrosis in the early stage developed to pancreatic necrosis, and 2 patients with the presence of necrosis in the early stage improved). The sensitivity, specificity, and accuracy of 120 kV portal venous phase images for the diagnosis of pancreatic necrosis were 50.0% (3/6), 100% (11/11), and 82.4% (14/17), respectively, and it had a good diagnostic value (AUC=0.856, P=0.018). The sensitivity, specificity, and accuracy of 120 kV portal venous phase images combined with iodine maps created from dual-source DECT for predicting pancreatic necrosis were 100% (6/6), 90.9% (10/11), and 94.1% (16/17), respectively, and this method had good value too (AUC=0.977, P=0.002), which higher than that of 120 kV portal venous phase images (P=0.002). ConclusionsThe 120 kV portal venous phase images combined with iodine maps created from dual-source DECT is helpful to improve subjective judgment in the diagnosis of pancreatic necrosis in the early stage of acute pancreatitis. It also contributes to the display of hypo-perfusion area of the pancreatic parenchyma, and has higher diagnostic value.

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        • CHANGES IN BONE MICRO-ARCHITECTURE AND BONE MINERAL DENSITY FOLLOWING EXPERIMENTALOSTEONECROSIS OF FEMORAL HEAD BY LOCAL INJECTION OF ETHANOL IN CANINES

          【Abstract】 Objective To measure the changes of bone mineral density and bone micro-architecture of thefemoral head that harvested from the three-foot bearing ethanol destroyed canine model for osteonecrosis of femoral head, and discuss the influences of local injection of ethanol and biomechanical loading to the structural properties of the femoral head. Methods Twenty-four Beagles were divided randomly into four-foot bearing canines and three-foot bearing canines. One fore-l imb was fixed randomly in three-foot bearing canines. Osteonecrosis was induced in all experimental animals by local injection of 5 mL pure ethanol into one side of the femoral head. The hind l imbs injected with NS were acted as control group, that of three-foot canines injected with ethanol were acted as three-foot canine group, and that of four-foot canines injected with ethanol were acted as four-foot canine group. The contralateral femoral head was injected into equal amount of NS. Animals were sacrificed at the time intervals of 1, 3, 6, and 12 weeks after the injection of ethanol. Quantitative microcomputedtomography was used to characterize changes in bone micro-architecture and bone mineral density of femoralhead. Results The clear three-dimensional model of trabecular bone of necrotic femoral head were obtained. There were no significant differences among 3 groups according to the time l ine by 1 week after ethanol injection(P gt; 0.05). At 3 weeks after injection of ethanol, in three-foot canine group and four-foot canine group, the volume of BMC, BMD, BVF, and BS/BV increased gradually as the distance to the drill ing canal increased. There were significant differences between 3 regions (P lt; 0.05). At 6 weeks, in three-foot canine group and four-foot canine group, the volume of BMC, BMD,BVF, and Tb.N of region I and II decreased significantly compared with region III (P lt; 0.05). At 12 weeks, there are no differences among 3 groups (P gt; 0.05). There were significant decreases in BMD values, BVF, BS/BV, Tb.N, Tb.Sp and Tb.Th after the injection of pure ethanol. And, the changes were more and more obvious by the time l ine. These changes were differentiable at 3 weeks after injection of ethanol, and became obvious at 6 weeks. These changes were more obvious at the part that near the injection canal. The changes in threefoot canine group were more obvious than that in four-foot canine group. Conclusion Resorption of necrotic compact bone trabecular may weaken the structural properties of the femoral head. Moreover, remodel ing and repairing process of necrotic bone trabecular may be hampered by constant biomechanical loading that presented in three-foot bearing canines, and thereby further weaken the structural properties of the femoral head. Biomechanical loading may be one of the critical reasons that lead to the collapse of femoral head.

          Release date:2016-09-01 09:10 Export PDF Favorites Scan
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          2. 射丝袜