AIM: To determine the possible predisposing factors of bezoar-induced small bowel obstruction(b I-Sb O) and to discuss the diagnostic value of multi-slice spiral computed tomography,particularly contrast-enhanced scan...AIM: To determine the possible predisposing factors of bezoar-induced small bowel obstruction(b I-Sb O) and to discuss the diagnostic value of multi-slice spiral computed tomography,particularly contrast-enhanced scanning,in this condition.METHODS: A total of 35 b I-Sb O cases treated at our hospital from January 2007 to December 2013 were retrospectively analysed.Complete clinical and computed tomography(CT) data of the patients were available and confirmed by surgery.SbO was clinically diagnosed on the basis of clinical manifestations.Of the 35 patients,18 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT and 17 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT combined with contrastenhanced examination.Original images were processed using a GE ADW4.3 workstation to obtain MPR,CPR,MIP and CTA images.The images of all patients were evaluated by two abdominal imaging experts.The main analytical contents of planar scanning included intestinal bezoar conditions,changes in the intestinal wall and changes in peri-intestinal conditions.Vascular hyperaemia and arterial blood supply conditions at a specific obstruction site and the distal end of the obstruction site were evaluated through contrastenhanced examination.RESULTS: The proportion of males to females among the 35 cases was 1:1.69(13:22); median age was 63.3 years.The following cases were observed: 29(82.8%) cases occurred in autumn and winter and showed a history of consuming high amounts of persimmon and hawthorn; 19(54.3%) cases revealed a history of gastrointestinal surgery; 19 exhibited incomplete dentition,with missing partial or whole posterior teeth; 26 suffered from obstruction at the ileum.A total of 51 bezoars were found in these patients,of whom 16(45.7%) had multiple bezoars.CT planar scanning of bezoars showed lumps with mottled gas inside the intestinal cavity.Furthermore,9 cases of bezoars had envelopes and 11 cases were accompanied with thickening of the distal wall of the obstructed bowel.Scanning of 17 cases was enhanced; the results revealed that the mesenteric blood vessels at the obstruction site and the proximal site were dilated,and a total of 7 cases were accompanied with distal vascular dilation and intestinal wall thickening.CONCLUSION: b I-Sb O exhibits regional and seasonal characteristics.CT planar and contrast-enhanced scanning can be applied to diagnose and observe vascular conditions in obstructed zones.展开更多
Objective： To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein （PV） ostia for patients with refractory paroxysmal atrial fibrillation （AF） under multi-slice spiral ...Objective： To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein （PV） ostia for patients with refractory paroxysmal atrial fibrillation （AF） under multi-slice spiral computed tomography （MSCT） guidance before the procedure. Methods： A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation ofPV ostia. The 36 male and 22 female patients with mean age of （57.4±9.5） （32-79） years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimentional image of the left atrium （LA） and proximal PVs. Patients then underwent segmental radiofrequency ablation ofPV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. Results： No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was （17.1±9.3） months. Forty-one patients （95%） experienced improved quality of life one month after the procedure. Thirty-six patients （83%） showed stable sinus rhythm, while 10 patients （23%） required additional anti-arrhythmic drugs. AF returned≥1 time in 6 （14%） patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. Conclusion： It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.展开更多
BACKGROUND Older people are more likely to experience pelvic fractures than younger people.Multi-slice spiral computed tomography(CT)uses three-dimensional(3D)reconstruction technology to generate 3D images that can c...BACKGROUND Older people are more likely to experience pelvic fractures than younger people.Multi-slice spiral computed tomography(CT)uses three-dimensional(3D)reconstruction technology to generate 3D images that can clearly demonstrate the 3D space of fractures and detect fractures at a higher rate.AIM To investigate the clinical value of multi-slice spiral CT 3D reconstruction in the diagnosis of unstable pelvic fractures in the elderly as well as the effect of less invasive stabilization.METHODS A total of 86 patients with unstable pelvic fractures treated between March 2016 and March 2019 underwent femoral supracondylar bone traction before surgery.Pelvic radiography and multi-row spiral CT were performed successively once the patient’s vital signs and hemodynamic indices were stable.Secondary processing of the original data was performed to obtain 3D reconstruction images and determine the vertical displacement of the pelvis.After basic or complete reduction,minimally invasive internal fixation using hollow lag screws was performed.The detection rates of fracture location and classification by X-ray and CT reconstruction were compared.Patients were divided into two groups according to the presence or absence of preoperative 3D reconstruction to compare postoperative reduction,wound healing time,fracture healing time,hospitalization time,visual analog scale(VAS)score,poor internal fixation,and functional recovery.RESULTS The diagnostic coincidence rates of X-rays for pubic symphysis,ilium wing,sacroiliac periarticular,and sacral fractures were lower than those of CT reconstruction.The coincidence rate of CT reconstruction in the clinical classification of pelvic fractures was 100%,whereas 11 cases were misdiagnosed by X-ray;the total coincidence rate was 87.21%.The total excellent and good rates of postoperative reduction were significantly higher in the study group than in the control group(P<0.05).The wound healing,fracture healing,and hospitalization times were significantly shorter in the study group than in the control group(P<0.05).The VAS scores decreased in both groups postoperatively and were lower in the study group than in the control group(P<0.05).The total incidence of poor postoperative internal fixation was significantly lower in the study group than in the control group(P<0.05).The overall rate of postoperative functional recovery was significantly higher in the study group than in the control group(P<0.05).CONCLUSION Multi-slice spiral CT has high guiding significance for the diagnosis,classification,and treatment of unstable pelvic fractures in the elderly.Preoperative 3D reconstruction can effectively shorten the operation time and promote fracture healing,while minimally invasive internal fixation can effectively reduce pain and promote functional recovery of fracture sites,making it worthy of clinical application.展开更多
BACKGROUND The biological characteristics of gastric stromal tumors are complex,and their incidence has increased in recent years.Gastric stromal tumors(GST)have potential malignant tendencies,and the probability of t...BACKGROUND The biological characteristics of gastric stromal tumors are complex,and their incidence has increased in recent years.Gastric stromal tumors(GST)have potential malignant tendencies,and the probability of transformation into malignant tumors is as high as 20%-30%.AIM To investigate the value of multi-slice spiral computed tomography(MSCT)in the differential diagnosis of GST and benign gastric polyps,and GST risk stratification assessment.METHODS We included 64 patients with GST(GST group)and 60 with benign gastric polyps(control group),confirmed by pathological examination after surgery in PLA General Hospital,from January 2016 to June 2021.The differences in the MSCT imaging characteristic parameters and enhanced CT values between the two groups before surgery were compared.According to the National Institutes of Health’s standard,GST is divided into low-and high-risk groups for MSCT imaging characteristic parameters and enhanced CT values.RESULTS The incidences of extraluminal growth,blurred boundaries,and ulceration in the GST group were significantly higher than those in the control group(P<0.05).The CT values and enhanced peak CT values in the arterial phase in the CST group were higher than those in the control group(P<0.05).The MSCT differential diagnosis of GST and gastric polyp sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and areas under the curve(AUCs)were 73.44%,83.33%,26.56%,16.67%,0.784,respectively.The receiver operating characteristic curves were plotted with the arterial CT value and enhanced peak CT value,with a statistical difference.The results showed that the sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of arterial CT in the differential diagnosis of GST and gastric polyps were 80.18%,62.20%,19.82%,37.80%,and 0.710,respectively.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of the enhanced peak CT value in the differential diagnosis of GST and gastric polyps were 67.63%,60.40%,32.37%,39.60%,and 0.710,respectively.The incidence of blurred lesion boundaries and ulceration in the high-risk group was significantly higher than that in the low-risk group(P<0.05).The arterial phase and enhanced peak CT values in the high-risk group were significantly higher than those in the low-risk group(P<0.05).CONCLUSION Presurgical MSCT examination has important value in the differential diagnosis of GST and gastric benign polyps and can effectively evaluate the risk grade of GST patients.展开更多
BACKGROUND Recurrence is the major challenge facing endoscopic submucosal dissection(ESD)-based treatment therapies for early gastric cancer(EGC).Urgent development of simple and easy surveillance approaches will enha...BACKGROUND Recurrence is the major challenge facing endoscopic submucosal dissection(ESD)-based treatment therapies for early gastric cancer(EGC).Urgent development of simple and easy surveillance approaches will enhance clinical treatment of the disease.AIM To explore the role of computed tomography(CT)recurrence in evaluating EGC after ESD treatment.METHODS We retrospectively recruited patients from our endoscopy department,between January 2002 and December 2015,and analyzed their basic characteristics,including symptoms,CT results,and results of endoscopy with biopsy,among others.RESULTS Among a total of 2150 patients EGC patients surveyed,1362 met our inclusion and exclusion criteria and were therefore enrolled in our study.The cohort’s sensitivity of CT for recurrent GC and specificity were 44.22%and 43.86%,respectively,with negative and positive predictive values of 40.15%(275/685)and 48.01%(325/677),respectively.The area under the curve of arterial and venous CT values for recurrent EGC were 0.545,and 0.604,respectively.Receiver operating characteristic curve revealed no statistically significant differences between arterial and venous CT values for recurrent EGC.CONCLUSION Enhanced CT has superior diagnostic efficacy,but less accuracy,compared to gold standard techniques in patients with recurrent EGC.展开更多
We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography ...We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography （CT） and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.展开更多
The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postopera...The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.展开更多
BACKGROUND This study aimed to analyze the predictive value of multi-slice spiral computed tomography(CT)perfusion imaging for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.A total of ...BACKGROUND This study aimed to analyze the predictive value of multi-slice spiral computed tomography(CT)perfusion imaging for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.A total of 62 patients with cirrhotic portal hypertension and 28 healthy individuals were included.The results showed that multi-slice spiral CT perfusion imaging had a significant predictive value for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.The vascular area,number of vascular cross-sections,and gastric coronary vein diameter(GCVD)showed high predictive values,with the vascular area having the best predictive value.AIM To investigate the predictive accuracy of multi-slice spiral CT perfusion imaging for upper gastrointestinal bleeding in patients with cirrhosis and portal hypertension.METHODS This study included 62 patients with cirrhotic portal hypertension(disease group)and 28 healthy individuals(control group).The disease group was further divided into two subgroups:Group A(n=27,bleeding)and group B(n=35,no bleeding).All patients underwent multi-slice spiral CT perfusion imaging at our hospital,and we compared various parameters such as liver blood flow,vein size,number of blood vessels,and blood vessel area between the two groups.We employed statistical analysis to identify factors associated with upper gastrointestinal bleeding and created a graph comparing the predictive value of different factors for bleeding.RESULTS We found no difference in hepatic artery(HAP)levels among the three groups(all P>0.05).The portal vein levels in groups A and B were much lower than in the control group;group A was much lower than group B(all P<0.05).The HAP perfusion index levels in groups A and B were much higher than in the control group;group A was much higher than group B(all P<0.05).The portal vein diameter,splenic vein diameter,and GCVD levels in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The number of blood vessels and blood vessel area in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The statistical method showed a strong link between GCVD,number of blood vessels,blood vessel area,and upper gastrointestinal bleeding(odds ratio=1.275,1.346,1.397,P<0.05).The graph showed that GCVD,number of blood vessels,and blood vessel area could predict bleeding well,with blood vessel area having the best prediction power.CONCLUSION That multi-slice spiral CT perfusion imaging can predict upper gastrointestinal bleeding well in patients with cirrhosis and high blood pressure in the portal vein.GCVD,number of blood vessels,and blood vessel area had high prediction power.The blood vessel area had the best prediction power,with an area under the curve of 0.831.展开更多
Chronic inflammatory mechanisms in the arterial wall lead to atherosclerosis,and include endothelial cell damage,inflammation,apoptosis,lipoprotein deposition,calcification and fibrosis.Cardiac computed tomography ang...Chronic inflammatory mechanisms in the arterial wall lead to atherosclerosis,and include endothelial cell damage,inflammation,apoptosis,lipoprotein deposition,calcification and fibrosis.Cardiac computed tomography angiography(CCTA)has been shown to be a promising tool for non-invasive assessment of theses specific compositional and structural changes in coronary arteries.This review focuses on the technical background of CCTA-based quantitative plaque characterization.Furthermore,we discuss the available evidence for CCTA-based plaque characterization and the potential role of CCTA for risk stratification of patients with coronary artery disease.展开更多
One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promisin...One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method.展开更多
Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of ce...Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of cells of the bacterium Streptococcus gordonii(S.gordonii),an important early coloniser of dental plaque,to samples of stainless steel(SS)have been reported in this work.The primary aim motivating this study was to establish what affect,if any,the surface roughness and topology of samples of SS would have on the initial attachment of cells of the bacterium S.gordonii.This material and bacterium were chosen by virtue of their relevance to dental implants and dental implant infections.Prior to bacterial attachment,surfaces become conditioned by the interfacing environment(salivary pellicle from the oral cavity for instance).For this reason,cell attachment to samples of SS pre-coated with saliva was also studied.By implementing the Extended Derjaguin Landau Verwey and Overbeek(XDLVO)theory coupled with convection-diffusion-reaction equations and the surface roughness information,a computational model was developed to help better understand the physics of cell adhesion.Surface roughness was modelled by reconstructing the surface topography using statistical parameters derived from atomic force microscopy(AFM)measurements.Using this computational model,the effects of roughness and surface patterns on bacterial attachment were examined quantitatively in both static and flowing fluid environments.The results have shown that rougher surfaces(within the sub-microscale)generally increase bacterial attachment in static fluid conditions which quantitatively agrees with experimental measurements.Under flow conditions,computational fluid dynamics(CFD)simulations predicted reduced convection-diffusion inside the channel which would act to decrease bacterial attachment.When combined with surface roughness effects,the computational model also predicted that the surface topographies discussed within this work produced a slight decrease in overall bacterial attachment.This would suggest that the attachment-preventing effects of surface patterns dominate over the adhesion-favourable sub-microscale surface roughness;hence,producing a net reduction in adhered cells.This qualitatively agreed with experimental observations reported here and quantitatively matched experimental observations for low flow rates within measurement error.展开更多
文摘AIM: To determine the possible predisposing factors of bezoar-induced small bowel obstruction(b I-Sb O) and to discuss the diagnostic value of multi-slice spiral computed tomography,particularly contrast-enhanced scanning,in this condition.METHODS: A total of 35 b I-Sb O cases treated at our hospital from January 2007 to December 2013 were retrospectively analysed.Complete clinical and computed tomography(CT) data of the patients were available and confirmed by surgery.SbO was clinically diagnosed on the basis of clinical manifestations.Of the 35 patients,18 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT and 17 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT combined with contrastenhanced examination.Original images were processed using a GE ADW4.3 workstation to obtain MPR,CPR,MIP and CTA images.The images of all patients were evaluated by two abdominal imaging experts.The main analytical contents of planar scanning included intestinal bezoar conditions,changes in the intestinal wall and changes in peri-intestinal conditions.Vascular hyperaemia and arterial blood supply conditions at a specific obstruction site and the distal end of the obstruction site were evaluated through contrastenhanced examination.RESULTS: The proportion of males to females among the 35 cases was 1:1.69(13:22); median age was 63.3 years.The following cases were observed: 29(82.8%) cases occurred in autumn and winter and showed a history of consuming high amounts of persimmon and hawthorn; 19(54.3%) cases revealed a history of gastrointestinal surgery; 19 exhibited incomplete dentition,with missing partial or whole posterior teeth; 26 suffered from obstruction at the ileum.A total of 51 bezoars were found in these patients,of whom 16(45.7%) had multiple bezoars.CT planar scanning of bezoars showed lumps with mottled gas inside the intestinal cavity.Furthermore,9 cases of bezoars had envelopes and 11 cases were accompanied with thickening of the distal wall of the obstructed bowel.Scanning of 17 cases was enhanced; the results revealed that the mesenteric blood vessels at the obstruction site and the proximal site were dilated,and a total of 7 cases were accompanied with distal vascular dilation and intestinal wall thickening.CONCLUSION: b I-Sb O exhibits regional and seasonal characteristics.CT planar and contrast-enhanced scanning can be applied to diagnose and observe vascular conditions in obstructed zones.
文摘Objective： To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein （PV） ostia for patients with refractory paroxysmal atrial fibrillation （AF） under multi-slice spiral computed tomography （MSCT） guidance before the procedure. Methods： A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation ofPV ostia. The 36 male and 22 female patients with mean age of （57.4±9.5） （32-79） years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimentional image of the left atrium （LA） and proximal PVs. Patients then underwent segmental radiofrequency ablation ofPV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. Results： No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was （17.1±9.3） months. Forty-one patients （95%） experienced improved quality of life one month after the procedure. Thirty-six patients （83%） showed stable sinus rhythm, while 10 patients （23%） required additional anti-arrhythmic drugs. AF returned≥1 time in 6 （14%） patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. Conclusion： It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.
文摘BACKGROUND Older people are more likely to experience pelvic fractures than younger people.Multi-slice spiral computed tomography(CT)uses three-dimensional(3D)reconstruction technology to generate 3D images that can clearly demonstrate the 3D space of fractures and detect fractures at a higher rate.AIM To investigate the clinical value of multi-slice spiral CT 3D reconstruction in the diagnosis of unstable pelvic fractures in the elderly as well as the effect of less invasive stabilization.METHODS A total of 86 patients with unstable pelvic fractures treated between March 2016 and March 2019 underwent femoral supracondylar bone traction before surgery.Pelvic radiography and multi-row spiral CT were performed successively once the patient’s vital signs and hemodynamic indices were stable.Secondary processing of the original data was performed to obtain 3D reconstruction images and determine the vertical displacement of the pelvis.After basic or complete reduction,minimally invasive internal fixation using hollow lag screws was performed.The detection rates of fracture location and classification by X-ray and CT reconstruction were compared.Patients were divided into two groups according to the presence or absence of preoperative 3D reconstruction to compare postoperative reduction,wound healing time,fracture healing time,hospitalization time,visual analog scale(VAS)score,poor internal fixation,and functional recovery.RESULTS The diagnostic coincidence rates of X-rays for pubic symphysis,ilium wing,sacroiliac periarticular,and sacral fractures were lower than those of CT reconstruction.The coincidence rate of CT reconstruction in the clinical classification of pelvic fractures was 100%,whereas 11 cases were misdiagnosed by X-ray;the total coincidence rate was 87.21%.The total excellent and good rates of postoperative reduction were significantly higher in the study group than in the control group(P<0.05).The wound healing,fracture healing,and hospitalization times were significantly shorter in the study group than in the control group(P<0.05).The VAS scores decreased in both groups postoperatively and were lower in the study group than in the control group(P<0.05).The total incidence of poor postoperative internal fixation was significantly lower in the study group than in the control group(P<0.05).The overall rate of postoperative functional recovery was significantly higher in the study group than in the control group(P<0.05).CONCLUSION Multi-slice spiral CT has high guiding significance for the diagnosis,classification,and treatment of unstable pelvic fractures in the elderly.Preoperative 3D reconstruction can effectively shorten the operation time and promote fracture healing,while minimally invasive internal fixation can effectively reduce pain and promote functional recovery of fracture sites,making it worthy of clinical application.
文摘BACKGROUND The biological characteristics of gastric stromal tumors are complex,and their incidence has increased in recent years.Gastric stromal tumors(GST)have potential malignant tendencies,and the probability of transformation into malignant tumors is as high as 20%-30%.AIM To investigate the value of multi-slice spiral computed tomography(MSCT)in the differential diagnosis of GST and benign gastric polyps,and GST risk stratification assessment.METHODS We included 64 patients with GST(GST group)and 60 with benign gastric polyps(control group),confirmed by pathological examination after surgery in PLA General Hospital,from January 2016 to June 2021.The differences in the MSCT imaging characteristic parameters and enhanced CT values between the two groups before surgery were compared.According to the National Institutes of Health’s standard,GST is divided into low-and high-risk groups for MSCT imaging characteristic parameters and enhanced CT values.RESULTS The incidences of extraluminal growth,blurred boundaries,and ulceration in the GST group were significantly higher than those in the control group(P<0.05).The CT values and enhanced peak CT values in the arterial phase in the CST group were higher than those in the control group(P<0.05).The MSCT differential diagnosis of GST and gastric polyp sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and areas under the curve(AUCs)were 73.44%,83.33%,26.56%,16.67%,0.784,respectively.The receiver operating characteristic curves were plotted with the arterial CT value and enhanced peak CT value,with a statistical difference.The results showed that the sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of arterial CT in the differential diagnosis of GST and gastric polyps were 80.18%,62.20%,19.82%,37.80%,and 0.710,respectively.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of the enhanced peak CT value in the differential diagnosis of GST and gastric polyps were 67.63%,60.40%,32.37%,39.60%,and 0.710,respectively.The incidence of blurred lesion boundaries and ulceration in the high-risk group was significantly higher than that in the low-risk group(P<0.05).The arterial phase and enhanced peak CT values in the high-risk group were significantly higher than those in the low-risk group(P<0.05).CONCLUSION Presurgical MSCT examination has important value in the differential diagnosis of GST and gastric benign polyps and can effectively evaluate the risk grade of GST patients.
文摘BACKGROUND Recurrence is the major challenge facing endoscopic submucosal dissection(ESD)-based treatment therapies for early gastric cancer(EGC).Urgent development of simple and easy surveillance approaches will enhance clinical treatment of the disease.AIM To explore the role of computed tomography(CT)recurrence in evaluating EGC after ESD treatment.METHODS We retrospectively recruited patients from our endoscopy department,between January 2002 and December 2015,and analyzed their basic characteristics,including symptoms,CT results,and results of endoscopy with biopsy,among others.RESULTS Among a total of 2150 patients EGC patients surveyed,1362 met our inclusion and exclusion criteria and were therefore enrolled in our study.The cohort’s sensitivity of CT for recurrent GC and specificity were 44.22%and 43.86%,respectively,with negative and positive predictive values of 40.15%(275/685)and 48.01%(325/677),respectively.The area under the curve of arterial and venous CT values for recurrent EGC were 0.545,and 0.604,respectively.Receiver operating characteristic curve revealed no statistically significant differences between arterial and venous CT values for recurrent EGC.CONCLUSION Enhanced CT has superior diagnostic efficacy,but less accuracy,compared to gold standard techniques in patients with recurrent EGC.
文摘We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography （CT） and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.
基金the Coordination for the Improvement of Higher Education Personnel(CAPES)programmeScience without borders from Brazilian governmentthe Research Foundation Flanders(FWO)from Flemish government for the fellowship support
文摘The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.
基金Supported by the Hebei Medical Science Project Research Program Project,No.20201411.
文摘BACKGROUND This study aimed to analyze the predictive value of multi-slice spiral computed tomography(CT)perfusion imaging for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.A total of 62 patients with cirrhotic portal hypertension and 28 healthy individuals were included.The results showed that multi-slice spiral CT perfusion imaging had a significant predictive value for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.The vascular area,number of vascular cross-sections,and gastric coronary vein diameter(GCVD)showed high predictive values,with the vascular area having the best predictive value.AIM To investigate the predictive accuracy of multi-slice spiral CT perfusion imaging for upper gastrointestinal bleeding in patients with cirrhosis and portal hypertension.METHODS This study included 62 patients with cirrhotic portal hypertension(disease group)and 28 healthy individuals(control group).The disease group was further divided into two subgroups:Group A(n=27,bleeding)and group B(n=35,no bleeding).All patients underwent multi-slice spiral CT perfusion imaging at our hospital,and we compared various parameters such as liver blood flow,vein size,number of blood vessels,and blood vessel area between the two groups.We employed statistical analysis to identify factors associated with upper gastrointestinal bleeding and created a graph comparing the predictive value of different factors for bleeding.RESULTS We found no difference in hepatic artery(HAP)levels among the three groups(all P>0.05).The portal vein levels in groups A and B were much lower than in the control group;group A was much lower than group B(all P<0.05).The HAP perfusion index levels in groups A and B were much higher than in the control group;group A was much higher than group B(all P<0.05).The portal vein diameter,splenic vein diameter,and GCVD levels in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The number of blood vessels and blood vessel area in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The statistical method showed a strong link between GCVD,number of blood vessels,blood vessel area,and upper gastrointestinal bleeding(odds ratio=1.275,1.346,1.397,P<0.05).The graph showed that GCVD,number of blood vessels,and blood vessel area could predict bleeding well,with blood vessel area having the best prediction power.CONCLUSION That multi-slice spiral CT perfusion imaging can predict upper gastrointestinal bleeding well in patients with cirrhosis and high blood pressure in the portal vein.GCVD,number of blood vessels,and blood vessel area had high prediction power.The blood vessel area had the best prediction power,with an area under the curve of 0.831.
文摘Chronic inflammatory mechanisms in the arterial wall lead to atherosclerosis,and include endothelial cell damage,inflammation,apoptosis,lipoprotein deposition,calcification and fibrosis.Cardiac computed tomography angiography(CCTA)has been shown to be a promising tool for non-invasive assessment of theses specific compositional and structural changes in coronary arteries.This review focuses on the technical background of CCTA-based quantitative plaque characterization.Furthermore,we discuss the available evidence for CCTA-based plaque characterization and the potential role of CCTA for risk stratification of patients with coronary artery disease.
文摘One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method.
基金Subash Bommu Chinnaraj acknowledges the Newcastle University SAGE DTA studentshipEPSRC DTP scholarshipfunding from the Engineering and Physical Sciences Research Council(No.EP/K039083/1)。
文摘Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of cells of the bacterium Streptococcus gordonii(S.gordonii),an important early coloniser of dental plaque,to samples of stainless steel(SS)have been reported in this work.The primary aim motivating this study was to establish what affect,if any,the surface roughness and topology of samples of SS would have on the initial attachment of cells of the bacterium S.gordonii.This material and bacterium were chosen by virtue of their relevance to dental implants and dental implant infections.Prior to bacterial attachment,surfaces become conditioned by the interfacing environment(salivary pellicle from the oral cavity for instance).For this reason,cell attachment to samples of SS pre-coated with saliva was also studied.By implementing the Extended Derjaguin Landau Verwey and Overbeek(XDLVO)theory coupled with convection-diffusion-reaction equations and the surface roughness information,a computational model was developed to help better understand the physics of cell adhesion.Surface roughness was modelled by reconstructing the surface topography using statistical parameters derived from atomic force microscopy(AFM)measurements.Using this computational model,the effects of roughness and surface patterns on bacterial attachment were examined quantitatively in both static and flowing fluid environments.The results have shown that rougher surfaces(within the sub-microscale)generally increase bacterial attachment in static fluid conditions which quantitatively agrees with experimental measurements.Under flow conditions,computational fluid dynamics(CFD)simulations predicted reduced convection-diffusion inside the channel which would act to decrease bacterial attachment.When combined with surface roughness effects,the computational model also predicted that the surface topographies discussed within this work produced a slight decrease in overall bacterial attachment.This would suggest that the attachment-preventing effects of surface patterns dominate over the adhesion-favourable sub-microscale surface roughness;hence,producing a net reduction in adhered cells.This qualitatively agreed with experimental observations reported here and quantitatively matched experimental observations for low flow rates within measurement error.
