This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both commo...This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.展开更多
The pore structure images of ore particles located at different heights of leaching column were scanned with X-ray computerized tomography (CT) scanner, the porosity and pore size distribution were calculated and the ...The pore structure images of ore particles located at different heights of leaching column were scanned with X-ray computerized tomography (CT) scanner, the porosity and pore size distribution were calculated and the geometrical shape and connectivity of pores were analyzed based on image process method, and the three dimensional reconstruction of pore structure images was realized. The results show that the porosity of ore particles bed in leaching column is 42.92%, 41.72%, 39.34% at top, middle and bottom zone, respectively. Obviously it has spatial variability and decreases appreciably along the height of the column. The overall average porosity obtained by image processing is 41.33% while the porosity gotten from general measurement method in laboratory is 42.77% showing the results of both methods are consistent well. The pore structure of ore granular media is characterized as a dynamical space network composed of interconnected pore bodies and pore throats. The ratio of throats with equivalent diameter less than 1.91 mm to the total pores is 29.31%, and that of the large pores with equivalent diameter more than 5.73 mm is 2.90%.展开更多
Primary malignant lymphoma of the prostate is exceedingly rare.Here we report a case of a 65-year-old man who presented with increased urinary frequency,urinary urgency,and urinary incontinence for two years.Benign pr...Primary malignant lymphoma of the prostate is exceedingly rare.Here we report a case of a 65-year-old man who presented with increased urinary frequency,urinary urgency,and urinary incontinence for two years.Benign prostatic hypertrophy was suspected at primary impression.Ultrasound revealed a hypoechoic lesion of the prostate.The total serum prostate-specific antigen was within normal range.Positron emission tomography/computerized tomography(PET/CT)showed a hypermetabolic prostatic lesion.Prostate biopsy was consistent with a non-germinal center diffuse large B cell lymphoma.There was complete remission of the prostatic lesion following six cycles of chemotherapy as shown on the second PET/CT imaging.18F-fluoro-deoxy glucose PET/CT is not only a complement to conventional imaging,but also plays a significant role in the diagnosis and evaluation of treatment response of prostatic lymphoma.展开更多
In order to investigate the application of proton magnetic resonance spectroscopy （ill-MRS） and computerized tomography （CT） in the quantitative diagnosis of nonalcoholic fatty liver disease （NAFLD） and evaluati...In order to investigate the application of proton magnetic resonance spectroscopy （ill-MRS） and computerized tomography （CT） in the quantitative diagnosis of nonalcoholic fatty liver disease （NAFLD） and evaluation of therapeutic effects, 22 patients with NAFLD were selected according to the Chinese Medical Association＇s （CMA） standard of the NAFLD in comparison with 20 healthy volunteers （as control group）. Blood samples for biochemistry were collected. The severity of hepatosteatosis was evaluated by ^1H-MRS scan and CT scan of liver. The intrahepatic content of lipid （IHCL） and CT value ratio of liver to spleen were calculated. The patients in NAFLD group were treated with Ganzhixiao Capsule for 8 weeks. The changes in IHCL and CT value ratio of liver to spleen were observed before and after treatment. In NAFLD group serum ALT, TG, IHCL calculated by ^1HMRS were increased and CT value ratio of liver to spleen decreased significantly as compared with control group. After treatment for 8 weeks serum ALT, TG, IHCL were decreased significantly, while CT value ratio of liver to spleen increased significantly in NAFLD group. It was suggested that IHCL could be measured precisely by ^1HMRS. NAFLD was treated effectively by Ganzhixiao capsule.展开更多
The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an ...The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.展开更多
For positioning a moving target, a maximum intensity projection (MIP) or average intensity projection (AIP) image derived from 4DCT is often used as the reference image which is matched to free breathing cone-beam CT ...For positioning a moving target, a maximum intensity projection (MIP) or average intensity projection (AIP) image derived from 4DCT is often used as the reference image which is matched to free breathing cone-beam CT (FBCBCT) before treatment. This method can be highly accurate if the respiratory motion of the patient is stable. However, a patient’s breathing pattern is often irregular. The purpose of this study is to investigate the effects of irregular respiration on positioning accuracy for a moving target aligned with FBCBCT. Nine patients’ respiratory motion curves were selected to drive a Quasar motion phantom with one embedded cubic and two spherical targets. A 4DCT of the phantom was acquired on a CT scanner (Philips Brilliance 16) equipped with a Varian RPM system. The phase binned 4DCT images and the corresponding MIP and AIP images were transferred into Eclipse for analysis. FBCBCTs of the phantom driven by the same respiratory curves were also acquired on a Varian TrueBeam and fused such that both CBCT and MIP/AIP images share the same target zero positions. The sphere and cube volumes and centroid differences (alignment error) determined by MIP, AIP and FBCBCT images were calculated, respectively. Compared to the volume determined by MIP, the volumes of the cube, large sphere, and small sphere in AIP and FBCBCT images were smaller. The alignment errors for the cube, large sphere and small sphere with center to center matches between MIP and FBCBCT were 2.5 ± 1.8 mm, 2.4 ± 2.1 mm, and 3.8 ± 2.8 mm, and the alignment errors between AIP and FBCBCT were 0.5 ± 1.1 mm, 0.3 ± 0.8 mm, and 1.8 ± 2.0 mm, respectively. AIP images appear to be superior reference images to MIP images. However, irregular respiratory pattern could compromise the positioning accuracy, especially for smaller targets.展开更多
BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to impr...BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to improve treatment efficacy.AIM To evaluate the efficacy and safety of computerized tomography-guided the-rapeutic percutaneous puncture catheter drainage(CT-TPPCD)combined with somatostatin(SS)in the treatment of SAP.METHODS Forty-two SAP patients admitted to The Second Affiliated Hospital of Fujian Medical University from June 2020 to June 2023 were selected.On the basis of routine treatment,20 patients received SS therapy(control group)and 22 patients were given CT-TPPCD plus SS intervention(research group).The efficacy,safety(pancreatic fistula,intra-abdominal hemorrhage,sepsis,and organ dysfunction syndrome),abdominal bloating and pain relief time,bowel recovery time,hospital stay,inflammatory indicators(C-reactive protein,interleukin-6,and pro-calcitonin),and Acute Physiology and Chronic Health Evaluation(APACHE)II score of both groups were evaluated for comparison.RESULTS Compared with the control group,the research group had a markedly higher total effective rate,faster abdominal bloating and pain relief and bowel recovery,INTRODUCTION Pancreatitis,an inflammatory disease occurring in the pancreatic tissue,is classified as either acute or chronic and is associated with high morbidity and mortality,imposing a socioeconomic burden[1,2].The pathogenesis of this disease involves early protease activation,activation of nuclear factor kappa-B-related inflammatory reactions,and infiltration of immune cells[3].Severe acute pancreatitis(SAP)is a serious condition involving systemic injury and subsequent possible organ failure,accounting for 20%of all acute pancreatitis cases[4].SAP is also characterized by rapid onset,critical illness and unsatisfactory prognosis and is correlated with serious adverse events such as systemic inflammatory response syn-drome and acute lung injury,threatening the health of patients[5,6].Therefore,timely and effective therapeutic inter-ventions are of great significance for improving patient prognosis and ensuring therapeutic effects.Somatostatin(SS),a peptide hormone that can be secreted by endocrine cells and the central nervous system,is in-volved in the regulatory mechanism of glucagon and insulin synthesis in the pancreas[7].It has complex and pleiotropic effects on the gastrointestinal tract,which can inhibit the release of gastrointestinal hormones and negatively modulate the exocrine function of the stomach,pancreas and bile,while exerting a certain influence on the absorption of the di-gestive system[8,9].SS has shown certain clinical effectiveness when applied to SAP patients and can regulate the severity of SAP and immune inflammatory responses,and this regulation is related to its influence on leukocyte apoptosis and adhesion[10,11].Computerized tomography-guided therapeutic percutaneous puncture catheter drainage(CT-TPPCD)is a surgical procedure to collect lesion fluid and pus samples from necrotic lesions and perform puncture and drainage by means of CT image examination and precise positioning[12].In the research of Liu et al[13],CT-TPPCD applied to pa-tients undergoing pancreatic surgery contributes to not only good curative effects but also a low surgical risk.Baudin et al[14]also reported that CT-TPPCD has a clinical success rate of 64.6%in patients with acute infectious necrotizing pan-creatitis,with nonfatal surgery-related complications found in only two cases,suggesting that this procedure is clinically effective and safe in the treatment of the disease.In light of the limited studies on the efficacy and safety of SS plus CT-TPPCD in SAP treatment,this study performed a relevant analysis to improve clinical outcomes in SAP patients.展开更多
We read with great interest the article by Vege et al published in issue 34 of World J Gastroenterol 2010. The article evaluates the ability of contrast-enhanced computerized tomography (CECT) to characterize the natu...We read with great interest the article by Vege et al published in issue 34 of World J Gastroenterol 2010. The article evaluates the ability of contrast-enhanced computerized tomography (CECT) to characterize the nature of peripancreatic collections found at surgery. The results of their study indicate that most of the peripancreatic collections seen on CECT in patients with severe acute pancreatitis who require operative intervention contain necrotic tissue and CECT has a limited role in differentiating various types of collections. However, there are some points that need to be addressed, including data about the stage of acute pancreatitis in which CECT was done and the time span between CECT examination and surgery.展开更多
Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients w...Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients with different CTDs were recruited and underwent lung HRCT and PFT. Eerythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum ferritin (SF), anti-SSA, and so on were tested. Based on HRCT, a patient was classified into ILD group (CTD+ILD) or non-ILD group (CTD-ILD). HRCT, PFT, and laboratory markers were compared according to CTDs and CTD-associated ILDs. Results. The incidences of ILD were 79.6%, 82.0%, 89.7%, and 97.1% respectively for Rheumatoid arthritis (RA), primary Sjogren’s symptom (pSS), dermatomyositis/polymyositis (DM/PM), and systemic sclerosis (SSc) groups. RA and pSS patients exhibited more nodules, patching, ground-glass opacity, and cord shadow foci in HRCT, DM/PM and SSc patients exhibited more reticular opacity and honeycombing foci. RA and pSS patients exhibited more obstructive ventilatory disorder, small airway dysfunction and emphysema in PFT, and DM/PM and SSc patients exhibited more restrictive ventilatory disorder, mixed ventilatory disorder. ESR, CRP and SF were significantly higher in total CTD+ILD group than in total CTD-ILD group (P = 0.047, 0.006, 0.004, respectively), and higher in different CTD+ ILD groups than in comparable CTD-ILD groups (P = 0.049, 0.048, and 0.023, pSS+ILD, SSc+ILD and RA+ILD compared to pSS-ILD, SSc-ILD and RA-ILD, respectively for ESR, CRP, SF). The positive rate of anti-SSA was significantly higher in DM/PM+ILD group than in DM/PM-ILD group (P = 0.025). Conclusions. The manifestations and incidences of ILDs differ among different CTDs in HRCT and PFT, and inflammation and anti-SSA are positively correlated with ILDs in different CTDs, which provide important evidences for judging disease condition and prognosis.展开更多
BACKGROUND Laparoscopic rectal cancer radical surgery is a complex procedure affected by various factors.However,the existing literature lacks standardized parameters for the pelvic region and soft tissues,which hampe...BACKGROUND Laparoscopic rectal cancer radical surgery is a complex procedure affected by various factors.However,the existing literature lacks standardized parameters for the pelvic region and soft tissues,which hampers the establishment of consistent conclusions.AIM To comprehensively assess 16 pelvic and 7 soft tissue parameters through computerized tomography(CT)-based three-dimensional(3D)reconstruction,providing a strong theoretical basis to address challenges in laparoscopic rectal cancer radical surgery.METHODS We analyzed data from 218 patients who underwent radical laparoscopic surgery for rectal cancer,and utilized CT data for 3D pelvic reconstruction.Specific anatomical points were carefully marked and measured using advanced 3D modeling software.To analyze the pelvic and soft tissue parameters,we emp-loyed statistical methods including paired sample t-tests,Wilcoxon rank-sum tests,and correlation analysis.RESULTS The investigation highlighted significant sex disparities in 14 pelvic bone parameters and 3 soft tissue parameters.Males demonstrated larger measurements in pelvic depth and overall curvature,smaller measurements in pelvic width,a larger mesorectal fat area,and a larger anterior-posterior abdominal diameter.By contrast,females exhibited wider pelvises,shallower depth,smaller overall curvature,and an increased amount of subcutaneous fat tissue.However,there were no significant sex differences observed in certain parameters such as sacral curvature height,superior pubococcygeal diameter,rectal area,visceral fat area,waist circumference,and transverse abdominal diameter.CONCLUSION The reconstruction of 3D CT data enabled accurate pelvic measurements,revealing significant sex differences in both pelvic and soft tissue parameters.This study design offer potential in predicting surgical difficulties and creating personalized surgical plans for male rectal cancer patients with a potentially“difficult pelvis”,ultimately improving surgical outcomes.Further research and utilization of these parameters could lead to enhanced surgical methods and patient care in laparoscopic rectal cancer radical surgery.展开更多
BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physi...BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physiology.AIM To determine the tracheobronchial branching angles in pediatric and adult populations by using the multislice computed tomography(CT)and minimum intensity projection(MinIP)technique,which is a non-invasive method.METHODS Our study was carried out retrospectively.Patients who underwent contrast and non-contrast CT examination,whose anatomically and pathophysiologically good tracheobronchial system and lung parenchyma images were obtained,were included in the study.Measurements were made in the coronal plane of the lung parenchyma.In the coronal plane,right main bronchus-left main bronchus angle,right upper lobe bronchus-intermedius bronchus angle,right middle lobe bronchus-right lower lobe bronchus angle,left upper lobe bronchus-left lower lobe bronchus angle were measured.RESULTS The study population consisted of 1511 patients,753 pediatric(mean age:13.4±4.3;range:1-18 years)and 758 adults(mean age:54.3±17.3;range:19-94 years).In our study,tracheal bifurcation angle was found to be 73.3°±13.7°(59.6°-87°)in the whole population.In the pediatric group,the right-left main coronal level was found to be higher in boys compared to girls(74.6°±12.9°vs 71.2°±13.9°,P=0.001).In the adult group,the right-left main coronal level was found to be lower in males compared to females(71.9°±12.9°vs 75.8°±14.7°,P<0.001).CONCLUSIONS Our study,with the number of 1511 patients,is the first study in the literature with the largest number of patient populations including pediatric and adult demographic data,measuring the angle values of the tracheobronchial system using multislice CT and MinIP technique.Study data will not only be a guide during invasive procedures,but it can also guide studies to be done with imaging methods.展开更多
Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and exper...Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and experimental explorations have focused on two-dimensional(2D)chaotic dielectric microcavities,but there have been minimal studies on three-dimensional(3D)ones because precise geometrical information of a 3D microcavity can be difficult to obtain.Here,we image 3D microcavities with submicron resolution using X-ray microcomputed tomography(μCT),enabling nondestructive imaging that preserves the sample for subsequent use.By analyzing the ray dynamics of a typical deformed microsphere,we demonstrate that a sufficient deformation along all three dimensions can lead to chaotic ray trajectories over extended time scales.Notably,using the X-rayμCT reconstruction results,the phase space chaotic ray dynamics of a deformed microsphere are accurately established.X-rayμCT could become a unique platform for the characterization of such deformed 3D microcavities by providing a precise means for determining the degree of deformation necessary for potential applications in ray chaos and quantum chaos.展开更多
Understanding the mechanisms of gas transport and the resulting preferential pathways formation through bentonite-based barriers is essential for their performance evaluation.In this experimental study,gas migration w...Understanding the mechanisms of gas transport and the resulting preferential pathways formation through bentonite-based barriers is essential for their performance evaluation.In this experimental study,gas migration within a heterogenous mixture of MX80 bentonite pellets and powder with a ratio of 80/20 in dry mass was investigated.A novel X-ray transparent constant volume cell has been developed to assess the effect of gas pressure,material heterogeneities,and water vapor gas saturation on breakthrough pressure and gas pathways.The new cell allows to perform high-resolution X-ray computed micro-tomography(X-ray μCT)scans to track microstructural changes during different phases of saturation and gas injection.Experimental results showed that the gas breakthrough occurred when the pressure was raised to 3 MPa.This is slightly higher than the expected swelling pressure(2.9 MPa)of the bentonite sample.Each gas injection was followed by a long resaturation phase restoring material homogeneity at μCT resolution scale(16 mm).However,the elapsed time needed for gas to breakthrough at 3 MPa diminished at each subsequent injection test.X-ray μCT results also revealed the opening of the specimen/cell wall interface during gas passage.This opening expanded as the injection pressure increased.The gas flow along the interface was associated with the development of dilatant pathways inside the sample,although they did not reach the outlet surface.It was observed that the water vapor gas saturation had no effect on the breakthrough pressure.These findings enhance the understanding of the complex mechanisms underlying microstructural evolution and gas pathway development within the highly heterogeneous mixture.The experimental outcomes highlight the effectiveness of X-ray μCT to improve quality protocols for engineering design and safety assessments of engineered barriers.展开更多
Despite lung cancer(LC) screening by low-dose computerized tomography(LDCT) gaining many proponents worldwide, for many years it was not recognized as a life-prolonging and cost-effective procedure, until recently. Pr...Despite lung cancer(LC) screening by low-dose computerized tomography(LDCT) gaining many proponents worldwide, for many years it was not recognized as a life-prolonging and cost-effective procedure, until recently. Prospective observational studies had not been able to prove that this screening prolongs survival, but they helped to specify the inclusion and exclusion criteria. Long-awaited results of a prospective, randomized trial finally provided the evidence that LC screening with LDCT can prolong survival of the screened population. Several costeffectiveness analyses were performed to justify mass introduction of this screening. Results of these analyses are equivocal, although conclusions highly depend upon inclusion and exclusion criteria, methods of analysis and prices of medical procedures which differ between countries as well as the incidence of other pulmonary nodules, especially tuberculosis. Therefore, costeffectiveness analysis should be performed separately for every country. Cost-effectiveness depends especially upon the rate of false-positive results and the rate of unnecessary diagnostic, screening and treatment procedures. To ensure high cost-effectiveness, LC screening should be performed in accordance with screening protocol, in dedicated screening centers equipped with nodule volume change analysis, or as a prospective non-randomized trial, to ensure compliance with the inclusion and exclusion criteria. To ensure high cost-effectiveness of LC screening, future research should concentrate on determination of highrisk groups and further specifying the inclusion and exclusion criteria.展开更多
Objective：To evaluate the clinical value with positron emission tomography/computerized tomography（PET/CT） imaging for the detection of vulnerable plaque in atherosclerotic lesions. Methods：Sixty people with a age...Objective：To evaluate the clinical value with positron emission tomography/computerized tomography（PET/CT） imaging for the detection of vulnerable plaque in atherosclerotic lesions. Methods：Sixty people with a age of over 60[mean age （69.2 ± 7.1）years] underwent three dimension（3D） whole-body fluorine-18-2-fluoro-2-deoxy-D-glucose（^18F-FDG） PET/CT imaging and were evaluated retrospectively, including 6 cases assessed as normal and 54 cases with active atherosclerotic plaque. Fifty-four cases with SUVs and CT values in the aortic wall of high-FDG-uptake were measured retrospectively. These high-FDG-uptake cases in the aortic wall were divided into three groups according their CT value. Cases in group 1 had high uptake in atherosclerotic lesions of the aortic wall with CT value of less than 60 Hu（soft plaque）. Cases in group 2 had high uptake with CT value between 60-100 Hu （intermediate plaque）, Cases in group 3 had high uptake with CT value more than 100 Hu（calcified plaque）, Group 4 was normal. Results： In group 1, there were 42 high-FDG-uptake sites （average SUV 1.553 ± 0.486）. In group 2, there were 30 high-FDG-uptake sites（average SUV 1.393 ± 0.296）. In group 3, there were 36 high-FDG-uptake sites（average SUV 1.354 ± 0.189）. In group 4, there were 33 normal-FDG-uptake sites （average SUV was 1.102 ± 0.141）, The SUVs showed significant difference among the four groups（F = 678.909, P = 0.000）. There were also significant difference found between the normal-FDG-uptake group and the high-FDG-uptake groups（P = 0.000, 0.000, 0.001, respectively）. Conclusion：Different degrees of ^18F-FDG uptake in active large atherosclerotic plaque were shown in different stages of atherosclerotic plaque formation. The soft plaque had the highest FDG uptake in this study. This suggested that ^18F- FDG PET/CT imaging may be of great potential value in early diagnosis and monitoring of vulnerable soft plaque in atherosclerotic lesions.展开更多
Transcatheter aortic valve implantation(TAVI) has been shown in improve outcome of severe aortic stenosis(AS) patients, deemed surgical high-risk or inoperable, and has grown popular in the past decade. The procedure ...Transcatheter aortic valve implantation(TAVI) has been shown in improve outcome of severe aortic stenosis(AS) patients, deemed surgical high-risk or inoperable, and has grown popular in the past decade. The procedure requires accurate prior planning, and demands an integration of a "Heart Team" consisted from cardiac surgeons, interventional cardiologists, and imaging experts. The role of cardiac imaging and especially multi-slice computerized tomography(MSCT) has been a mainstay of pre-evaluation of severe AS patients that allows to accurately depict and size the cardiac and vascular structures, and has become the primary tool for procedural planning. This article is aimed to evaluate current uses of MSCT in severe AS patients undergoing TAVI, delineate the various measurements derived from this modality and review current literature regarding it's advantages over other techniques.展开更多
BACKGROUND Postoperative pancreatic fistula(POPF)is the most fearful complication after pancreatic surgery and can lead to severe postoperative complications such as surgical site infections,sepsis and bleeding.A prev...BACKGROUND Postoperative pancreatic fistula(POPF)is the most fearful complication after pancreatic surgery and can lead to severe postoperative complications such as surgical site infections,sepsis and bleeding.A previous study which identified cut-offs of drains amylase levels(DALs)determined on postoperative day(POD)1 and POD3,was able to significantly predict POPF,abdominal collections and biliary fistulas,when related to specific findings detected at the abdominal computerized tomography(CT)scan routinely performed on POD3.AIM To validate the cut-offs of DALs in POD1 and POD3,established during the previous study,to assess the risk of clinically relevant POPF and confirm the usefulness of abdominal CT scan on POD3 in patients at increased risk of abdominal collection.METHODS The DALCUT trial is an interventional prospective study.All patients who will undergo pancreatoduodenectomy(PD)for periampullary neoplasms will be considered eligible.All patients will receive clinical staging and,if eligible for surgery,will undergo routine preoperative evaluation.After the PD,daily DALs will be evaluated from POD1.Drains removal and possible requirement of abdominal CT scans in POD3 will be managed on the basis of the outcome of DALs in the first three postoperative days.RESULTS This prospective study could validate the role of DALs in the management of surgical drains and in assessing the risk or relevant complications after PD.Drains could be removed in POD3 in case of POD1 DALs<666 U/L and POD3 DALs<207 U/L.In case of POD3 DALs≥252,abdominal CT scan will be performed in POD3 to identify abdominal collections≥5 cm.In this latter category of patients,drains could be maintained beyond POD3.CONCLUSION The results of this trial will contribute to a better knowledge of POPF and management of surgical drains.展开更多
The spleen is one of the most frequently affected organs in sickle cell anemia (SCA). This study aims to characterize the spleen in sickle cell anemia patients using contrast enhanced computerized tomography scanning ...The spleen is one of the most frequently affected organs in sickle cell anemia (SCA). This study aims to characterize the spleen in sickle cell anemia patients using contrast enhanced computerized tomography scanning (CECT). 67 patients with SCA from different Saudi Arabian areas were enrolled;ages are ranged from 10 months to 28 years old. The spleen was assessed with CT for abdominal pain and/or unexplained fever. The evaluation was done at different contrast enhancement scanning phases. The study showed that the least number of affected patients was from Eastern Saudi Arabia (1.5%) followed by Asseer (16.4%) then Gazan representing 82.1%. The most common type of SCA affected the Saudi children is Hemoglobin SS Disease (Hb SS) constituting 41 (61.2%). The spleen size, lymph nodes size, spleen Hounsfield (HU), splenic vein diameter and the correlation with the associated findings were evaluated for all of the patients. In children affected with SCA: 26 (38.8%) have splenomegaly, 18 (26.9%) have atrophied spleen and 2 (3.0%) are with very small tissue like structure. Lesions found in the spleen were abscess, infarction, cyst, and calcifications. At the spleen hilum region;dilated splenic vein, presence of multiple collaterals, and thrombus were also been detected. Significantly correlations were noticed between lesions type, child age, enlargement of spleen and splenic lymph nodes at P ≤ 0.033, P ≤ 0.010 and P ≤ 0.012 respectively and showed an evidence that the reduction of the HU and advanced age have significant relation with changing of the spleen size at P ≤ 0.004 and P ≤ 0.000 respectively. Spleen lesions’ enhancement pattern is well emerged in both venous and delay phase and it was significantly related with the scanning phase at P ≤ 0.000 and with different types of SCA at P ≤ 0.037, and P ≤ 0.055 in venous and delay phase in respectively. CECT offers a number of morphological criteria that can be applied to differentiate hypodense lesions of the spleen in SCA. CT characterization criteria of hypodense splenic lesions are acknowledged to aid interpretation during evaluation of abdominal CT images of the spleen in symptomatic patients with sickle cell anemia.展开更多
Pulmonary embolism (PE) is potentially life threatening condition which requires adequate diagnosis. Since computerized tomography pulmonary angiography (CTPA) described the presence of a clot subjectively, an objecti...Pulmonary embolism (PE) is potentially life threatening condition which requires adequate diagnosis. Since computerized tomography pulmonary angiography (CTPA) described the presence of a clot subjectively, an objective and quantification method to characterize plural parenchymal abnormality, pulmonary vessels and heart is needed (in order to diagnose PE). This study was directed to investigate whether the presence of plural parenchymal findings correlates with the PE and as well, it was designed to answer two basic questions based on CTPA findings done for clinical suspicion of PE: firstly, what are the plural parenchymal abnormalities associated with PE;secondly, correlation of PE with the presence of heart changes and pulmonary vessels measurements. CTPA scans were acquired for 55 patients suspected of having PE and another 50 subjects who were considered as control. The clinical signs and pleuroparenchymal abnormalities, pulmonary artery tree measurements, right ventricle and atrium diameters, Inter ventricular septum width as well as the myocardium thickening were characterized and correlated with PE. The results showed that the PE patients group has more dilated measurements than the normal control subjects. The right ventricle diameter changes were found to be significantly related to the presence of PE at p ≤ 0.001. Significant changes at p ≤ 0.005 were also noticed in the pulmonary trunk diameter as well as the right and left main pulmonary arteries with no significant changes detected in the distal portion of both pulmonary arteries diameters. The common complaints from PE patients were chest pain, shortness of breathing, lower limb swelling, tachycardia and syncope. Consolidation, ground glass opacifications, mosaic, right ventricle morphological changes and pleural effusion were present in the majority of patients undergoing CTPA for the clinical suspicion of PE. CTPA is considered as the diagnostic modality of choice in characterization of pulmonary vessels, atrium and ventricle changes as well as pleura parenchymal abnormalities in patients with or without PE.展开更多
The article is to study the development of computer-aided design of X-ray microtomography—the device for investigating the structure and construction of three-dimensional images of organic and inorganic objects on th...The article is to study the development of computer-aided design of X-ray microtomography—the device for investigating the structure and construction of three-dimensional images of organic and inorganic objects on the basis of shadow projections. This article provides basic information regarding CAD of X-ray microtomography and a scheme consisting of three levels. The article also shows basic relations of X-ray computed tomography, the generalized scheme of an X-ray microtomographic scanner. The methods of X-ray imaging of the spatial microstructure and morphometry of materials are described. The main characteristics of an X-ray microtomographic scanner, the X-ray source, X-ray optical elements and mechanical components of the positioning system are shown. The block scheme and software functional scheme for intelligent neural network system of analysis of the internal microstructure of objects are presented. The method of choice of design parameters of CAD of X-ray microtomography aims at improving the quality of design and reducing costs of it. It is supposed to reduce the design time and eliminate the growing number of engineers involved in development and construction of X-ray microtomographic scanners.展开更多
基金Project(2023YFB4606200)supported by the National Key Research and Development Program of ChinaProject(2023-SSRF-HZ-503114-2)supported by Shanghai Synchrotron Radiation Facility,Instrument BL16U2,China。
文摘This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.
基金Project(2004CB619205) supported by the National Key Fundamental Research and Development Program of ChinaProject(50325415) supported by the National Science Fund for Distinguished Young ScholarsProject(50574099) supported by the National Natural Science Foundation of China
文摘The pore structure images of ore particles located at different heights of leaching column were scanned with X-ray computerized tomography (CT) scanner, the porosity and pore size distribution were calculated and the geometrical shape and connectivity of pores were analyzed based on image process method, and the three dimensional reconstruction of pore structure images was realized. The results show that the porosity of ore particles bed in leaching column is 42.92%, 41.72%, 39.34% at top, middle and bottom zone, respectively. Obviously it has spatial variability and decreases appreciably along the height of the column. The overall average porosity obtained by image processing is 41.33% while the porosity gotten from general measurement method in laboratory is 42.77% showing the results of both methods are consistent well. The pore structure of ore granular media is characterized as a dynamical space network composed of interconnected pore bodies and pore throats. The ratio of throats with equivalent diameter less than 1.91 mm to the total pores is 29.31%, and that of the large pores with equivalent diameter more than 5.73 mm is 2.90%.
文摘Primary malignant lymphoma of the prostate is exceedingly rare.Here we report a case of a 65-year-old man who presented with increased urinary frequency,urinary urgency,and urinary incontinence for two years.Benign prostatic hypertrophy was suspected at primary impression.Ultrasound revealed a hypoechoic lesion of the prostate.The total serum prostate-specific antigen was within normal range.Positron emission tomography/computerized tomography(PET/CT)showed a hypermetabolic prostatic lesion.Prostate biopsy was consistent with a non-germinal center diffuse large B cell lymphoma.There was complete remission of the prostatic lesion following six cycles of chemotherapy as shown on the second PET/CT imaging.18F-fluoro-deoxy glucose PET/CT is not only a complement to conventional imaging,but also plays a significant role in the diagnosis and evaluation of treatment response of prostatic lymphoma.
文摘In order to investigate the application of proton magnetic resonance spectroscopy （ill-MRS） and computerized tomography （CT） in the quantitative diagnosis of nonalcoholic fatty liver disease （NAFLD） and evaluation of therapeutic effects, 22 patients with NAFLD were selected according to the Chinese Medical Association＇s （CMA） standard of the NAFLD in comparison with 20 healthy volunteers （as control group）. Blood samples for biochemistry were collected. The severity of hepatosteatosis was evaluated by ^1H-MRS scan and CT scan of liver. The intrahepatic content of lipid （IHCL） and CT value ratio of liver to spleen were calculated. The patients in NAFLD group were treated with Ganzhixiao Capsule for 8 weeks. The changes in IHCL and CT value ratio of liver to spleen were observed before and after treatment. In NAFLD group serum ALT, TG, IHCL calculated by ^1HMRS were increased and CT value ratio of liver to spleen decreased significantly as compared with control group. After treatment for 8 weeks serum ALT, TG, IHCL were decreased significantly, while CT value ratio of liver to spleen increased significantly in NAFLD group. It was suggested that IHCL could be measured precisely by ^1HMRS. NAFLD was treated effectively by Ganzhixiao capsule.
基金Funded by Chinese National Natural Science Foundation of China(No.U2006224)。
文摘The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.
文摘For positioning a moving target, a maximum intensity projection (MIP) or average intensity projection (AIP) image derived from 4DCT is often used as the reference image which is matched to free breathing cone-beam CT (FBCBCT) before treatment. This method can be highly accurate if the respiratory motion of the patient is stable. However, a patient’s breathing pattern is often irregular. The purpose of this study is to investigate the effects of irregular respiration on positioning accuracy for a moving target aligned with FBCBCT. Nine patients’ respiratory motion curves were selected to drive a Quasar motion phantom with one embedded cubic and two spherical targets. A 4DCT of the phantom was acquired on a CT scanner (Philips Brilliance 16) equipped with a Varian RPM system. The phase binned 4DCT images and the corresponding MIP and AIP images were transferred into Eclipse for analysis. FBCBCTs of the phantom driven by the same respiratory curves were also acquired on a Varian TrueBeam and fused such that both CBCT and MIP/AIP images share the same target zero positions. The sphere and cube volumes and centroid differences (alignment error) determined by MIP, AIP and FBCBCT images were calculated, respectively. Compared to the volume determined by MIP, the volumes of the cube, large sphere, and small sphere in AIP and FBCBCT images were smaller. The alignment errors for the cube, large sphere and small sphere with center to center matches between MIP and FBCBCT were 2.5 ± 1.8 mm, 2.4 ± 2.1 mm, and 3.8 ± 2.8 mm, and the alignment errors between AIP and FBCBCT were 0.5 ± 1.1 mm, 0.3 ± 0.8 mm, and 1.8 ± 2.0 mm, respectively. AIP images appear to be superior reference images to MIP images. However, irregular respiratory pattern could compromise the positioning accuracy, especially for smaller targets.
基金Supported by 2022 Fujian Medical University Qihang Fund General Project Plan,No.2022QH1120。
文摘BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to improve treatment efficacy.AIM To evaluate the efficacy and safety of computerized tomography-guided the-rapeutic percutaneous puncture catheter drainage(CT-TPPCD)combined with somatostatin(SS)in the treatment of SAP.METHODS Forty-two SAP patients admitted to The Second Affiliated Hospital of Fujian Medical University from June 2020 to June 2023 were selected.On the basis of routine treatment,20 patients received SS therapy(control group)and 22 patients were given CT-TPPCD plus SS intervention(research group).The efficacy,safety(pancreatic fistula,intra-abdominal hemorrhage,sepsis,and organ dysfunction syndrome),abdominal bloating and pain relief time,bowel recovery time,hospital stay,inflammatory indicators(C-reactive protein,interleukin-6,and pro-calcitonin),and Acute Physiology and Chronic Health Evaluation(APACHE)II score of both groups were evaluated for comparison.RESULTS Compared with the control group,the research group had a markedly higher total effective rate,faster abdominal bloating and pain relief and bowel recovery,INTRODUCTION Pancreatitis,an inflammatory disease occurring in the pancreatic tissue,is classified as either acute or chronic and is associated with high morbidity and mortality,imposing a socioeconomic burden[1,2].The pathogenesis of this disease involves early protease activation,activation of nuclear factor kappa-B-related inflammatory reactions,and infiltration of immune cells[3].Severe acute pancreatitis(SAP)is a serious condition involving systemic injury and subsequent possible organ failure,accounting for 20%of all acute pancreatitis cases[4].SAP is also characterized by rapid onset,critical illness and unsatisfactory prognosis and is correlated with serious adverse events such as systemic inflammatory response syn-drome and acute lung injury,threatening the health of patients[5,6].Therefore,timely and effective therapeutic inter-ventions are of great significance for improving patient prognosis and ensuring therapeutic effects.Somatostatin(SS),a peptide hormone that can be secreted by endocrine cells and the central nervous system,is in-volved in the regulatory mechanism of glucagon and insulin synthesis in the pancreas[7].It has complex and pleiotropic effects on the gastrointestinal tract,which can inhibit the release of gastrointestinal hormones and negatively modulate the exocrine function of the stomach,pancreas and bile,while exerting a certain influence on the absorption of the di-gestive system[8,9].SS has shown certain clinical effectiveness when applied to SAP patients and can regulate the severity of SAP and immune inflammatory responses,and this regulation is related to its influence on leukocyte apoptosis and adhesion[10,11].Computerized tomography-guided therapeutic percutaneous puncture catheter drainage(CT-TPPCD)is a surgical procedure to collect lesion fluid and pus samples from necrotic lesions and perform puncture and drainage by means of CT image examination and precise positioning[12].In the research of Liu et al[13],CT-TPPCD applied to pa-tients undergoing pancreatic surgery contributes to not only good curative effects but also a low surgical risk.Baudin et al[14]also reported that CT-TPPCD has a clinical success rate of 64.6%in patients with acute infectious necrotizing pan-creatitis,with nonfatal surgery-related complications found in only two cases,suggesting that this procedure is clinically effective and safe in the treatment of the disease.In light of the limited studies on the efficacy and safety of SS plus CT-TPPCD in SAP treatment,this study performed a relevant analysis to improve clinical outcomes in SAP patients.
文摘We read with great interest the article by Vege et al published in issue 34 of World J Gastroenterol 2010. The article evaluates the ability of contrast-enhanced computerized tomography (CECT) to characterize the nature of peripancreatic collections found at surgery. The results of their study indicate that most of the peripancreatic collections seen on CECT in patients with severe acute pancreatitis who require operative intervention contain necrotic tissue and CECT has a limited role in differentiating various types of collections. However, there are some points that need to be addressed, including data about the stage of acute pancreatitis in which CECT was done and the time span between CECT examination and surgery.
文摘Objective. To study the difference of interstitial lung diseases (ILDs) in high-resolution computerized tomography and pulmonary function test among different connective tissue diseases (CTDs). Methods. 209 patients with different CTDs were recruited and underwent lung HRCT and PFT. Eerythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum ferritin (SF), anti-SSA, and so on were tested. Based on HRCT, a patient was classified into ILD group (CTD+ILD) or non-ILD group (CTD-ILD). HRCT, PFT, and laboratory markers were compared according to CTDs and CTD-associated ILDs. Results. The incidences of ILD were 79.6%, 82.0%, 89.7%, and 97.1% respectively for Rheumatoid arthritis (RA), primary Sjogren’s symptom (pSS), dermatomyositis/polymyositis (DM/PM), and systemic sclerosis (SSc) groups. RA and pSS patients exhibited more nodules, patching, ground-glass opacity, and cord shadow foci in HRCT, DM/PM and SSc patients exhibited more reticular opacity and honeycombing foci. RA and pSS patients exhibited more obstructive ventilatory disorder, small airway dysfunction and emphysema in PFT, and DM/PM and SSc patients exhibited more restrictive ventilatory disorder, mixed ventilatory disorder. ESR, CRP and SF were significantly higher in total CTD+ILD group than in total CTD-ILD group (P = 0.047, 0.006, 0.004, respectively), and higher in different CTD+ ILD groups than in comparable CTD-ILD groups (P = 0.049, 0.048, and 0.023, pSS+ILD, SSc+ILD and RA+ILD compared to pSS-ILD, SSc-ILD and RA-ILD, respectively for ESR, CRP, SF). The positive rate of anti-SSA was significantly higher in DM/PM+ILD group than in DM/PM-ILD group (P = 0.025). Conclusions. The manifestations and incidences of ILDs differ among different CTDs in HRCT and PFT, and inflammation and anti-SSA are positively correlated with ILDs in different CTDs, which provide important evidences for judging disease condition and prognosis.
基金2021 Zhejiang Province Public Welfare Technology Application Research Funding Project,No.LGC21H160002Basic Scientific Research Projects in Wenzhou City in 2022,No.Y20220885Wenzhou Medical University 2021 Higher Education Teaching Reform Project,No.JG2021167.
文摘BACKGROUND Laparoscopic rectal cancer radical surgery is a complex procedure affected by various factors.However,the existing literature lacks standardized parameters for the pelvic region and soft tissues,which hampers the establishment of consistent conclusions.AIM To comprehensively assess 16 pelvic and 7 soft tissue parameters through computerized tomography(CT)-based three-dimensional(3D)reconstruction,providing a strong theoretical basis to address challenges in laparoscopic rectal cancer radical surgery.METHODS We analyzed data from 218 patients who underwent radical laparoscopic surgery for rectal cancer,and utilized CT data for 3D pelvic reconstruction.Specific anatomical points were carefully marked and measured using advanced 3D modeling software.To analyze the pelvic and soft tissue parameters,we emp-loyed statistical methods including paired sample t-tests,Wilcoxon rank-sum tests,and correlation analysis.RESULTS The investigation highlighted significant sex disparities in 14 pelvic bone parameters and 3 soft tissue parameters.Males demonstrated larger measurements in pelvic depth and overall curvature,smaller measurements in pelvic width,a larger mesorectal fat area,and a larger anterior-posterior abdominal diameter.By contrast,females exhibited wider pelvises,shallower depth,smaller overall curvature,and an increased amount of subcutaneous fat tissue.However,there were no significant sex differences observed in certain parameters such as sacral curvature height,superior pubococcygeal diameter,rectal area,visceral fat area,waist circumference,and transverse abdominal diameter.CONCLUSION The reconstruction of 3D CT data enabled accurate pelvic measurements,revealing significant sex differences in both pelvic and soft tissue parameters.This study design offer potential in predicting surgical difficulties and creating personalized surgical plans for male rectal cancer patients with a potentially“difficult pelvis”,ultimately improving surgical outcomes.Further research and utilization of these parameters could lead to enhanced surgical methods and patient care in laparoscopic rectal cancer radical surgery.
文摘BACKGROUND The data obtained on the anatomical knowledge of the tracheobronchial system can be used for diagnosis,treatment and interventional interventions in areas such as anesthesia,thoracic surgery,pulmonary physiology.AIM To determine the tracheobronchial branching angles in pediatric and adult populations by using the multislice computed tomography(CT)and minimum intensity projection(MinIP)technique,which is a non-invasive method.METHODS Our study was carried out retrospectively.Patients who underwent contrast and non-contrast CT examination,whose anatomically and pathophysiologically good tracheobronchial system and lung parenchyma images were obtained,were included in the study.Measurements were made in the coronal plane of the lung parenchyma.In the coronal plane,right main bronchus-left main bronchus angle,right upper lobe bronchus-intermedius bronchus angle,right middle lobe bronchus-right lower lobe bronchus angle,left upper lobe bronchus-left lower lobe bronchus angle were measured.RESULTS The study population consisted of 1511 patients,753 pediatric(mean age:13.4±4.3;range:1-18 years)and 758 adults(mean age:54.3±17.3;range:19-94 years).In our study,tracheal bifurcation angle was found to be 73.3°±13.7°(59.6°-87°)in the whole population.In the pediatric group,the right-left main coronal level was found to be higher in boys compared to girls(74.6°±12.9°vs 71.2°±13.9°,P=0.001).In the adult group,the right-left main coronal level was found to be lower in males compared to females(71.9°±12.9°vs 75.8°±14.7°,P<0.001).CONCLUSIONS Our study,with the number of 1511 patients,is the first study in the literature with the largest number of patient populations including pediatric and adult demographic data,measuring the angle values of the tracheobronchial system using multislice CT and MinIP technique.Study data will not only be a guide during invasive procedures,but it can also guide studies to be done with imaging methods.
基金support from the Okinawa Institute of Science and Technology Graduate University(OIST),the China Scholarship Council(CSC)(Grant No.202306680004)the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Korean government(MSIT)(Grant Nos.RS-2024-00403036 and RS-202500521202)+2 种基金support from the Japan Society for the Promotion of Science(JSPS)KAKENHI through Grant-in-Aid for Scientific Research(C)(Grant No.23K04617)Grant-in-Aid for Early-Career Scientists(Grant No.22K14621)Grant-in-Aid for JSPS fellows(Grant No.25KJ2244)。
文摘Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and experimental explorations have focused on two-dimensional(2D)chaotic dielectric microcavities,but there have been minimal studies on three-dimensional(3D)ones because precise geometrical information of a 3D microcavity can be difficult to obtain.Here,we image 3D microcavities with submicron resolution using X-ray microcomputed tomography(μCT),enabling nondestructive imaging that preserves the sample for subsequent use.By analyzing the ray dynamics of a typical deformed microsphere,we demonstrate that a sufficient deformation along all three dimensions can lead to chaotic ray trajectories over extended time scales.Notably,using the X-rayμCT reconstruction results,the phase space chaotic ray dynamics of a deformed microsphere are accurately established.X-rayμCT could become a unique platform for the characterization of such deformed 3D microcavities by providing a precise means for determining the degree of deformation necessary for potential applications in ray chaos and quantum chaos.
基金funding from the European Union's Horizon 2020 research and innovation program European Joint Program on RadioactiveWaste Management(EURAD)(2019e2024)WP-Gas‘Mechanistic understanding of gas transport in clay materials’under Grant agreement No.847593.
文摘Understanding the mechanisms of gas transport and the resulting preferential pathways formation through bentonite-based barriers is essential for their performance evaluation.In this experimental study,gas migration within a heterogenous mixture of MX80 bentonite pellets and powder with a ratio of 80/20 in dry mass was investigated.A novel X-ray transparent constant volume cell has been developed to assess the effect of gas pressure,material heterogeneities,and water vapor gas saturation on breakthrough pressure and gas pathways.The new cell allows to perform high-resolution X-ray computed micro-tomography(X-ray μCT)scans to track microstructural changes during different phases of saturation and gas injection.Experimental results showed that the gas breakthrough occurred when the pressure was raised to 3 MPa.This is slightly higher than the expected swelling pressure(2.9 MPa)of the bentonite sample.Each gas injection was followed by a long resaturation phase restoring material homogeneity at μCT resolution scale(16 mm).However,the elapsed time needed for gas to breakthrough at 3 MPa diminished at each subsequent injection test.X-ray μCT results also revealed the opening of the specimen/cell wall interface during gas passage.This opening expanded as the injection pressure increased.The gas flow along the interface was associated with the development of dilatant pathways inside the sample,although they did not reach the outlet surface.It was observed that the water vapor gas saturation had no effect on the breakthrough pressure.These findings enhance the understanding of the complex mechanisms underlying microstructural evolution and gas pathway development within the highly heterogeneous mixture.The experimental outcomes highlight the effectiveness of X-ray μCT to improve quality protocols for engineering design and safety assessments of engineered barriers.
文摘Despite lung cancer(LC) screening by low-dose computerized tomography(LDCT) gaining many proponents worldwide, for many years it was not recognized as a life-prolonging and cost-effective procedure, until recently. Prospective observational studies had not been able to prove that this screening prolongs survival, but they helped to specify the inclusion and exclusion criteria. Long-awaited results of a prospective, randomized trial finally provided the evidence that LC screening with LDCT can prolong survival of the screened population. Several costeffectiveness analyses were performed to justify mass introduction of this screening. Results of these analyses are equivocal, although conclusions highly depend upon inclusion and exclusion criteria, methods of analysis and prices of medical procedures which differ between countries as well as the incidence of other pulmonary nodules, especially tuberculosis. Therefore, costeffectiveness analysis should be performed separately for every country. Cost-effectiveness depends especially upon the rate of false-positive results and the rate of unnecessary diagnostic, screening and treatment procedures. To ensure high cost-effectiveness, LC screening should be performed in accordance with screening protocol, in dedicated screening centers equipped with nodule volume change analysis, or as a prospective non-randomized trial, to ensure compliance with the inclusion and exclusion criteria. To ensure high cost-effectiveness of LC screening, future research should concentrate on determination of highrisk groups and further specifying the inclusion and exclusion criteria.
文摘Objective：To evaluate the clinical value with positron emission tomography/computerized tomography（PET/CT） imaging for the detection of vulnerable plaque in atherosclerotic lesions. Methods：Sixty people with a age of over 60[mean age （69.2 ± 7.1）years] underwent three dimension（3D） whole-body fluorine-18-2-fluoro-2-deoxy-D-glucose（^18F-FDG） PET/CT imaging and were evaluated retrospectively, including 6 cases assessed as normal and 54 cases with active atherosclerotic plaque. Fifty-four cases with SUVs and CT values in the aortic wall of high-FDG-uptake were measured retrospectively. These high-FDG-uptake cases in the aortic wall were divided into three groups according their CT value. Cases in group 1 had high uptake in atherosclerotic lesions of the aortic wall with CT value of less than 60 Hu（soft plaque）. Cases in group 2 had high uptake with CT value between 60-100 Hu （intermediate plaque）, Cases in group 3 had high uptake with CT value more than 100 Hu（calcified plaque）, Group 4 was normal. Results： In group 1, there were 42 high-FDG-uptake sites （average SUV 1.553 ± 0.486）. In group 2, there were 30 high-FDG-uptake sites（average SUV 1.393 ± 0.296）. In group 3, there were 36 high-FDG-uptake sites（average SUV 1.354 ± 0.189）. In group 4, there were 33 normal-FDG-uptake sites （average SUV was 1.102 ± 0.141）, The SUVs showed significant difference among the four groups（F = 678.909, P = 0.000）. There were also significant difference found between the normal-FDG-uptake group and the high-FDG-uptake groups（P = 0.000, 0.000, 0.001, respectively）. Conclusion：Different degrees of ^18F-FDG uptake in active large atherosclerotic plaque were shown in different stages of atherosclerotic plaque formation. The soft plaque had the highest FDG uptake in this study. This suggested that ^18F- FDG PET/CT imaging may be of great potential value in early diagnosis and monitoring of vulnerable soft plaque in atherosclerotic lesions.
文摘Transcatheter aortic valve implantation(TAVI) has been shown in improve outcome of severe aortic stenosis(AS) patients, deemed surgical high-risk or inoperable, and has grown popular in the past decade. The procedure requires accurate prior planning, and demands an integration of a "Heart Team" consisted from cardiac surgeons, interventional cardiologists, and imaging experts. The role of cardiac imaging and especially multi-slice computerized tomography(MSCT) has been a mainstay of pre-evaluation of severe AS patients that allows to accurately depict and size the cardiac and vascular structures, and has become the primary tool for procedural planning. This article is aimed to evaluate current uses of MSCT in severe AS patients undergoing TAVI, delineate the various measurements derived from this modality and review current literature regarding it's advantages over other techniques.
文摘BACKGROUND Postoperative pancreatic fistula(POPF)is the most fearful complication after pancreatic surgery and can lead to severe postoperative complications such as surgical site infections,sepsis and bleeding.A previous study which identified cut-offs of drains amylase levels(DALs)determined on postoperative day(POD)1 and POD3,was able to significantly predict POPF,abdominal collections and biliary fistulas,when related to specific findings detected at the abdominal computerized tomography(CT)scan routinely performed on POD3.AIM To validate the cut-offs of DALs in POD1 and POD3,established during the previous study,to assess the risk of clinically relevant POPF and confirm the usefulness of abdominal CT scan on POD3 in patients at increased risk of abdominal collection.METHODS The DALCUT trial is an interventional prospective study.All patients who will undergo pancreatoduodenectomy(PD)for periampullary neoplasms will be considered eligible.All patients will receive clinical staging and,if eligible for surgery,will undergo routine preoperative evaluation.After the PD,daily DALs will be evaluated from POD1.Drains removal and possible requirement of abdominal CT scans in POD3 will be managed on the basis of the outcome of DALs in the first three postoperative days.RESULTS This prospective study could validate the role of DALs in the management of surgical drains and in assessing the risk or relevant complications after PD.Drains could be removed in POD3 in case of POD1 DALs<666 U/L and POD3 DALs<207 U/L.In case of POD3 DALs≥252,abdominal CT scan will be performed in POD3 to identify abdominal collections≥5 cm.In this latter category of patients,drains could be maintained beyond POD3.CONCLUSION The results of this trial will contribute to a better knowledge of POPF and management of surgical drains.
文摘The spleen is one of the most frequently affected organs in sickle cell anemia (SCA). This study aims to characterize the spleen in sickle cell anemia patients using contrast enhanced computerized tomography scanning (CECT). 67 patients with SCA from different Saudi Arabian areas were enrolled;ages are ranged from 10 months to 28 years old. The spleen was assessed with CT for abdominal pain and/or unexplained fever. The evaluation was done at different contrast enhancement scanning phases. The study showed that the least number of affected patients was from Eastern Saudi Arabia (1.5%) followed by Asseer (16.4%) then Gazan representing 82.1%. The most common type of SCA affected the Saudi children is Hemoglobin SS Disease (Hb SS) constituting 41 (61.2%). The spleen size, lymph nodes size, spleen Hounsfield (HU), splenic vein diameter and the correlation with the associated findings were evaluated for all of the patients. In children affected with SCA: 26 (38.8%) have splenomegaly, 18 (26.9%) have atrophied spleen and 2 (3.0%) are with very small tissue like structure. Lesions found in the spleen were abscess, infarction, cyst, and calcifications. At the spleen hilum region;dilated splenic vein, presence of multiple collaterals, and thrombus were also been detected. Significantly correlations were noticed between lesions type, child age, enlargement of spleen and splenic lymph nodes at P ≤ 0.033, P ≤ 0.010 and P ≤ 0.012 respectively and showed an evidence that the reduction of the HU and advanced age have significant relation with changing of the spleen size at P ≤ 0.004 and P ≤ 0.000 respectively. Spleen lesions’ enhancement pattern is well emerged in both venous and delay phase and it was significantly related with the scanning phase at P ≤ 0.000 and with different types of SCA at P ≤ 0.037, and P ≤ 0.055 in venous and delay phase in respectively. CECT offers a number of morphological criteria that can be applied to differentiate hypodense lesions of the spleen in SCA. CT characterization criteria of hypodense splenic lesions are acknowledged to aid interpretation during evaluation of abdominal CT images of the spleen in symptomatic patients with sickle cell anemia.
文摘Pulmonary embolism (PE) is potentially life threatening condition which requires adequate diagnosis. Since computerized tomography pulmonary angiography (CTPA) described the presence of a clot subjectively, an objective and quantification method to characterize plural parenchymal abnormality, pulmonary vessels and heart is needed (in order to diagnose PE). This study was directed to investigate whether the presence of plural parenchymal findings correlates with the PE and as well, it was designed to answer two basic questions based on CTPA findings done for clinical suspicion of PE: firstly, what are the plural parenchymal abnormalities associated with PE;secondly, correlation of PE with the presence of heart changes and pulmonary vessels measurements. CTPA scans were acquired for 55 patients suspected of having PE and another 50 subjects who were considered as control. The clinical signs and pleuroparenchymal abnormalities, pulmonary artery tree measurements, right ventricle and atrium diameters, Inter ventricular septum width as well as the myocardium thickening were characterized and correlated with PE. The results showed that the PE patients group has more dilated measurements than the normal control subjects. The right ventricle diameter changes were found to be significantly related to the presence of PE at p ≤ 0.001. Significant changes at p ≤ 0.005 were also noticed in the pulmonary trunk diameter as well as the right and left main pulmonary arteries with no significant changes detected in the distal portion of both pulmonary arteries diameters. The common complaints from PE patients were chest pain, shortness of breathing, lower limb swelling, tachycardia and syncope. Consolidation, ground glass opacifications, mosaic, right ventricle morphological changes and pleural effusion were present in the majority of patients undergoing CTPA for the clinical suspicion of PE. CTPA is considered as the diagnostic modality of choice in characterization of pulmonary vessels, atrium and ventricle changes as well as pleura parenchymal abnormalities in patients with or without PE.
文摘The article is to study the development of computer-aided design of X-ray microtomography—the device for investigating the structure and construction of three-dimensional images of organic and inorganic objects on the basis of shadow projections. This article provides basic information regarding CAD of X-ray microtomography and a scheme consisting of three levels. The article also shows basic relations of X-ray computed tomography, the generalized scheme of an X-ray microtomographic scanner. The methods of X-ray imaging of the spatial microstructure and morphometry of materials are described. The main characteristics of an X-ray microtomographic scanner, the X-ray source, X-ray optical elements and mechanical components of the positioning system are shown. The block scheme and software functional scheme for intelligent neural network system of analysis of the internal microstructure of objects are presented. The method of choice of design parameters of CAD of X-ray microtomography aims at improving the quality of design and reducing costs of it. It is supposed to reduce the design time and eliminate the growing number of engineers involved in development and construction of X-ray microtomographic scanners.
