Objective To evaluate the accuracy of pedicle guide device for the placement of the pedicle screws. Methods Pedicle guide device was designed and made for the anatomical trait of pedicle. The 3-Danatomical data of the thoracic pedicles were measured by multislice spiral CT in two embalmed human cadaveric thoracic pedicles spine(T1 -T10). Depending on transverse section angle(TSA) and sagittal section angle(SSA) of pedicle axis, the degree of horizontal dial and sagittal dial were adjusted in the guide device. The screws wereinserted bilaterally in the thoracic pedicles by using the device. After pulling the screws out, the pathways were filled with contrast media. The TSA and SSA of developed pathways were measured. Results Analysis of the difference between pedicle axis and developed pathway was of no statistical significance(P＞0.05). Conclusion The guide device could be easilyoperated and guarantee high accuracy of the pathways of screws and the incidence of pedicle penetration could be significantly reduced.
Objective To investigate the methods of establishing 3-dimensional skull model using electron beam CT(EBCT) data rapid prototyping technique, andto discuss its application in repairing crainomaxillofacial trauma. Methods The data were obtained by EBCTcontinuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to workstation for 3-dimensional surface reconstruction by computeraided design software and the images were saved as STL file. The data can be usedto control a laser rapid-prototyping device(AFS-320QZ) to construct geometricmodel. The material for the model construction is a kind of laser-sensitive resinpower, which will become a mass when scanned by laser beam .The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufacture d3D model. One case of craniomaxillofacial bone defect resulting from trauma wasreconstructed with this method. The EBCT scanning showed that the defect area was 4 cm×6 cm. The nose was flat and deviated to left. Results The -3dimensional -skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimenstional anatomyand their relationship.The prefabricated implant by 3-dimensional model was well-matched with defect .The deformities of flat and deviated nose were corrected. The clinical result wassatisfactory after a follow-up of 17 months. Conclusion The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing craniomaxillofacial trauma.
Objective To summarize the methods and applications for quantitative measurement of iron in human.Methods The methods and applications for quantitative measurement of iron in human were analyzed retrospectively via reviewing the literatures domesticly and abroad， and summarized the advantages and disadvantages respectively. Results The methods for quantitative measurement of iron included laboratory tests， pathology examinations， CT， superconducting quantum interference device investigation （SQUID）， and MRI. Conclusions Laboratory test is the most simple and economic method for quantitative measurement of iron in human. Percutaneous liver biopsy is the gold standardmethod. Radiologic examinations， especially MRI， may be main methods of measuring liver iron content in future.
ObjectiveTo evaluate the diagnostic value of artificial intelligence (AI)-assisted diagnostic system for pulmonary cancer based on CT images.MethodsDatabases including PubMed, The Cochrane Library, EMbase, CNKI, WanFang Data and Chinese BioMedical Literature Database (CBM) were electronically searched to collect relevant studies on AI-assisted diagnostic system in the diagnosis of pulmonary cancer from 2010 to 2019. The eligible studies were selected according to inclusion and exclusion criteria, and the quality of included studies was assessed and the special information was identified. Then, meta-analysis was performed using RevMan 5.3, Stata 12.0 and SAS 9.4 softwares. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were pooled and the summary receiver operating characteristic (SROC) curve was drawn. Meta-regression analysis was used to explore the sources of heterogeneity.ResultsTotally 18 studies were included with 4 771 patients. Random effect model was used for the analysis due to the heterogeneity among studies. The results of meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnosis odds ratio and area under the SROC curve were 0.87 [95%CI (0.84, 0.90)], 0.89 [95%CI (0.84, 0.92)], 7.70 [95%CI (5.32, 11.15)], 0.14 [95%CI (0.11, 0.19)], 53.54 [95%CI (30.68, 93.42)] and 0.94 [95%CI (0.91, 0.95)], respectively.ConclusionAI-assisted diagnostic system based on CT images has high diagnostic value for pulmonary cancer, and thus it is worthy of clinical application. However, due to the limited quality and quantity of included studies, above results should be validated by more studies.
【Abstract】 Objective Using 16-slice multi-detector row helical CT (16-slice MDCT) to investigate the value of multiplanar reformation technique (MPR) in the diagnosis of bowel obstruction. Methods Thirty patients with surgically (27 cases) or clinically (3 cases) proofed diagnosis of bowel obstruction underwent 16-slice MDCT examination of the entire abdomen. All cases had plain CT scan, while 20 cases had additional contrast-enhanced CT scan at portal venous phase. In addition to the conventional axial images, the original CT raw data were then reconstructed into both coronal and sagittal images using MPR technique. Imaging findings were analyzed on axial, MPR coronal and sagittal images. Results Among the 30 patients with bowel obstruction, there were 8 cases caused by adhesion, 7 by simple intestinal tumor, 5 by intussusception (including caused by instestinal tumor), 4 by abdominal hernia, 2 by volvulus, 1 by ileocecal abscess, 1 by stenosis of mesenteric artery，1 by retroperitoneal cyst, and 1 by carcinoma in pancreatic tail. Six patients developed intestinal ischemia or strangulation. Both axial and MPR images correctly depicted the presence of bowel obstruction. Based on CT axial view （AV）, the site and the underlying etiology of bowel obstruction were determined in 26 (86.7%) and 22 (73.3%) patients respectively, while the combination with MPR coronal and sagittal images improved the diagnostic performance to 29 (96.7%) and 27 (90.0%) patients respectively. Both axial and MPR images correctly revealed the presence of intestinal ischemia or strangulation in 5 （83.3%）patients. Conclusion MPR technique of MDCT is very useful for evaluating the site and etiology of bowel obstruction, as well as the circulation status of involved bowel loop.
Objective To investigate the controlled release effect and the anti-cancer cell ability of a 5-FU loaded poly-L-lactic acid （PLLA） nanofibers membrane blending with keratin. Methods Making PLLA and keratin mix together and crosslinking to generate blending solution. Then the anti-cancer drug 5-FU was added into the solution to fabricate nanofibers membrane by high voltage electrospinning method. The micro morphology was observed by scanning electron microscope （SEM）. The controlled release effect of 5-FU from the nanofibers membrane was measured by high performance liquid chromatography （HPLC）. The cytotoxicity of 5-FU/PLLA keratin nanofibers membrane was evaluated by using 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay on HCT116 cell lines. At the meantime, cell growth morphology of HCT116 in experiment group were observed by microscope and transmission electron microscope. Results 5-FU could be dispersed homogeneous in the PLLA/keratin nanofibers membrane through SEM. HPLC suggested that 5-FU could be diffused out from the fibers slowly and uniformly, which corresponded the zero order kinetics basically. After different treatment, the longer time the 5-FU/PLLA keratin nanofibers （experiment group） immerse in the medium, the much more swelling, apoptosis, and necrocytosis of the cells were observed. The cell viability for experiment group was （47.5±2.8）% by MTT, while the PLLA keratin nanofibers without 5-FU had no significant impact on cell viability （93.9±2.8）%, which was statistic significance （P＜0.01）. Conclusion 5-FU/PLLA keratin nanofibers membrane owns good controlled release effect and satisfies cell inhibitory effect against HCT116 cells in vitro，which suggested that it has a promising prospect for clinical therapy.
【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.
Objective To review the principles and techniques of CT perfusion imaging and its applications in the imaging diagnosis of abdominal disorders. Methods All the relevant literatures were reviewed. The principles and techniques of CT perfusion imaging were described and summarized in detail. The functional information of a target abdominal organ (e.g. the liver and pancreas) revealed by CT perfusion imaging, such as hemodynamics and microcirculation status, was also evaluated. Results In addition to the morphologic information, CT perfusion imaging can also provide functional information about the circulation parameters of target abdominal organs. Moreover, such functional information can be generated for the neovasculature and microcirculation of tumor lesions of abdominal organs, which is very helpful for not only the diagnosis, but also the evaluation of tumor invasiveness and response to treatment. Conclusion CT perfusion imaging offers an effective method for studying abdominal disorders by providing functional information that is quite useful for the differential diagnosis and assessment of therapeutic response.
ObjectiveTo investigate the reliability and safety of the technique of percutaneous left ventricular transapical access guided by cardiac three dimensional CT angiography (3D-CTA) combined with echocardiography applied in structural heart defects.MethodsThe clinical data of 9 patients (7 males and 2 females with a median age of 50 years ranging from 43 to 64 years) with paravalvular leaks closed by percutaneous left ventricular transapical access in West China Hospital, from April 2015 to August 2018, were retrospectively analyzed. We applied preoperative cardiac 3D-CTA to define the puncture site and trace, which was established by combining with real-time guidance of transesophageal echocardiography (TEE/3D-TEE), and an occluder was deployed at the apical access point for hemostasis with real-time guidance of transthoracic echocardiography (TTE).ResultsThe puncture needles were successfully introduced into the left ventricular cavity at one time in all patients without injury of lung tissue, coronary artery or papillary muscle. There was no occluder displacement or apex bleeding. One patient developed pleural effusion caused by intercostal artery injury.ConclusionThat cardiac 3D-CTA is used to define puncture sites and trace with advantages of simplicity and repeatability. A safe access and secure exit of left ventricle can be achieved by combining with real-time guidance of echocardiography. There are acceptable technology-related complications.
ObjectiveTo explore the effect of icariin on early steroid-induced osteonecrosis of the femoral head in rabbits.MethodsFifty mature New Zealand rabbits (weighing, 2.5-3.0 kg) were randomly divided into control group (n=10), model group (n=20), and experimental group (n=20). The rabbits of model and experimental groups were injected with lipopolysaccharide and methylprednisolone to establish the animal model of early steroid-induced osteonecrosis of the femoral head. The rabbits of experimental group were feeded with icariin solution once a day for 6 weeks since the first injection of methylprednisolone, whereas the rabbits of control and model groups were given normal saline at the same time points. The left femoral heads were removed after 6 weeks and gross morphological features were evaluated. Micro-CT scan was performed to analyze the trabecular microstructure with the following parameters: trabecular bone volume to total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Tn), and trabecular separation (Tb.Sp). The Micro-CT scan was also converted to three-dimensional reconstruction images for observation. HE staining was applied to observe the trabecular structure and morphological changes of osteocytes and marrow adipocytes. It was also used to determine whether the samples of femoral heads occurred osteonecrosis based on the criteria for pathological diagnosis, and calculate the rate of empty lacunae.ResultsSeven rabbits died during the study, and 9, 16, and 18 rabbits in the control, model, and experimental groups, respectively, enrolled the final analysis. Compared with control group, the femoral head collapse and trabecular breaks were more obvious, and the trabeculae were sparse with irregular arrangement in the model group according to the results of gross observation, Micro-CT scan, and three-dimensional reconstruction images. But in the experimental group, the surface of femoral head was slight shrinking without obvious collapse, and the degeneration of trabecular structure was mild. According to bone microstructures analysis, the Tb.N, Tb.Tn, and BV/TV of femoral head in model and experimental groups were lower than those in control group, while the Tb.Sp in the model and experimental groups were significantly higher. The Tb.N, Tb.Tn, and BV/TV of femoral head in experimental group were higher than those in model group, while the Tb.Sp in the experimental group was significantly lower. The differences between groups were all significant (P<0.05). In the model group, HE staining showed that the number of osteocytes reduced, the number of empty lacunae increased, and the marrow adipocytes piled up in the space between femoral trabeculae, some even mashed together like a cyst. In the experimental group, the trabecular structure was still relatively complete compared with model group, no obvious apoptosis of osteocytes was observed, the size and number of adipocytes were basically normal. None of the animals in control group occurred osteonecrosis of the femoral head based on the criteria for pathological diagnosis, and the incidence of osteonecrosis were 81.3% (13/16) in the model group and 66.7% (12/18) in the experimental group, and the difference was not significant (P=0.448). The rate of empty lacunae of osteonecrotic femoral heads in the model group was 33.1%±1.4%, which was higher than that in experimental group (18.9%±0.8%) and in control group (12.7%±1.5%), and the differences between groups were significant (P<0.05).ConclusionThe icariin has a protective effect on the early steroid-induced osteonecrosis of the femoral head in rabbits, which can decrease osteocytes apoptosis, improve the bone microstructure, and delay such disease processes.