BACKGROUND Virtual reality(VR)has emerged as an innovative technology in endoscopy training,providing a simulated environment that closely resembles real-life scenarios and offering trainees a valuable platform to acq...BACKGROUND Virtual reality(VR)has emerged as an innovative technology in endoscopy training,providing a simulated environment that closely resembles real-life scenarios and offering trainees a valuable platform to acquire and enhance their endoscopic skills.This systematic review will critically evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.AIM To evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.By examining the current state of the field,this review seeks to identify gaps,challenges,and opportunities for further research and implementation of VR in endoscopic training.METHODS The study is a systematic review,following the guidelines for reporting systematic reviews set out by the PRISMA statement.A comprehensive search command was designed and implemented and run in September 2023 to identify relevant studies available,from electronic databases such as PubMed,Scopus,Cochrane,and Google Scholar.The results were systematically reviewed.RESULTS Sixteen articles were included in the final analysis.The total number of participants was 523.Five studies focused on both upper endoscopy and colonoscopy training,two on upper endoscopy training only,eight on colonoscopy training only,and one on sigmoidoscopy training only.Gastrointestinal Mentor virtual endoscopy simulator was commonly used.Fifteen reported positive results,indicating that VR-based training was feasible and acceptable for endoscopy learners.VR technology helped the trainees enhance their skills in manipulating the endoscope,reducing the procedure time or increasing the technical accuracy,in VR scenarios and real patients.Some studies show that the patient discomfort level decreased significantly.However,some studies show there were no significant differences in patient discomfort and pain scores between VR group and other groups.CONCLUSION VR training is effective for endoscopy training.There are several well-designed randomized controlled trials with large sample sizes,proving the potential of this innovative tool.Thus,VR should be more widely adopted in endoscopy training.Furthermore,combining VR training with conventional methods could be a promising approach that should be implemented in training.展开更多
Background Currently,many simulator systems for medical procedures are under development.These systems can provide new solutions for training,planning,and testing medical practices,improve performance,and optimize the...Background Currently,many simulator systems for medical procedures are under development.These systems can provide new solutions for training,planning,and testing medical practices,improve performance,and optimize the time of the exams.However,to achieve the best results,certain premises must be followed and applied to the model under development,such as usability,control,graphics realism,and interactive and dynamic gami-fication.Methods This study presents a system for simulating a medical examination procedure in the nasal cavity for training and research purposes,using a patient′s accurate computed tomography(CT)as a reference.The pathologies that are used as a guide for the development of the system are highlighted.Furthermore,an overview of current studies covering bench medical mannequins,3D printing,animals,hardware,software,and software that use hardware to boost user interaction,is given.Finally,a comparison with similar state-of-the-art studies is made.Results The main result of this work is interactive gamification techniques to propose an experience of simulation of an immersive exam by identifying pathologies present in the nasal cavity such as hypertrophy of turbinates,septal deviation adenoid hypertrophy,nasal polyposis,and tumor.展开更多
Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies...Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.展开更多
BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE ...BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE overlaps with severe portal hypertensive gastropathy(PHG).AIM To determine the added diagnostic value of virtual chromoendoscopy to high definition white light for real-time endoscopic diagnosis of GAVE and PHG.METHODS We developed an I-scan virtual chromoendoscopy criteria for diagnosis of GAVE and PHG.We tested our criteria in a cross-sectional cohort of cirrhotic adults with GAVE and PHG when high-definition white light endoscopy(HDWLE)diagnosis was in doubt.We then compared the accuracy of I-scan vs HDWLE alone to histology.RESULTS Twenty-three patients were included in this study(65.2%Caucasians and 60.9%males).Chronic hepatitis C was the predominant cause of cirrhosis(43.5%)and seven adults(30.4%)had confirmed GAVE on histology.I-scan had higher sensitivity(100%vs 85.7%)and specificity(75%vs 62.5%)in diagnosing GAVE compared to HDWLE.This translates into a higher,albeit not statistically significant,accuracy of I-scan in detecting GAVE compared to HDWLE alone(82%vs 70%).I-scan was less likely to lead to an accurate diagnosis of GAVE in patients on dialysis(P<0.05)and in patients with elevated creatinine(P<0.05).Iscan had similar accuracy to HDWLE in detecting PHG.CONCLUSION This pilot work supports that virtual chromoendoscopy may obviate the need for biopsies when the presence of GAVE is in doubt.Larger studies are needed to assess the impact of virtual chromoendoscopy on success of endoscopic therapy for GAVE.展开更多
The use of simulators as educational tools for medical procedures is spreading rapidly and many efforts have been made for their implementation in gastrointestinal endoscopy training. Endoscopy simulation training has...The use of simulators as educational tools for medical procedures is spreading rapidly and many efforts have been made for their implementation in gastrointestinal endoscopy training. Endoscopy simulation training has been suggested for ascertaining patient safety while positively influencing the trainees' learning curve. Virtual simulators are the most promising tool among all available types of simulators. These integrated modalities offer a human-like endoscopy experience by combining virtual images of the gastrointestinal tract and haptic realism with using a customized endoscope. From their first steps in the 1980s until today, research involving virtual endoscopic simulators can be divided in two categories: investigation of the impact of virtual simulator training in acquiring endoscopy skills and measuring competence. Emphasis should also be given to the financial impact of their implementation in endoscopy, including the cost of these state-of-theart simulators and the potential economic benefits from their usage. Advances in technology will contribute to the upgrade of existing models and the development of new ones; while further research should be carried out to discover new fields of application.展开更多
AIM:To present our experience of using 3D virtual intravascular endoscopy(VIE) to characterize and evaluate the intraluminal appearances of aortic dissection.METHODS:Ten patients with known aortic dissection underwent...AIM:To present our experience of using 3D virtual intravascular endoscopy(VIE) to characterize and evaluate the intraluminal appearances of aortic dissection.METHODS:Ten patients with known aortic dissection underwent dual-source computed tomography angiography and were included in the study.In addition to 2D axial and multiplanar reformatted images as well as 3D reconstructions,VIE images were created in each patient to demonstrate intraluminal views of the aorta and its branches,origin of artery branches and artery branch involvement by aortic dissection.RESULTS:Stanford A dissection was found in 8 patients and B dissection in the remaining 2 patients.VIE images were successfully generated in all of the patients with excellent visualization of the normal anatomical structures,intimal flap and intimal entrance tear,communication between true and false lumens,as well as assessment of the extent of aortic dissection.CONCLUSION:Our preliminary experience suggests that VIE could be used as a complementary tool to assist radiologists accurately evaluate aortic dissection so that better patient management can be achieved.展开更多
AIM:To improve the diagnosis of heterotopic pancreas by the use of contrastenhanced computed tomography(CT)imaging and CT virtual endoscopy(CTVE).METHODS:A total of six patients with heterotopic pancreas,as confirmed ...AIM:To improve the diagnosis of heterotopic pancreas by the use of contrastenhanced computed tomography(CT)imaging and CT virtual endoscopy(CTVE).METHODS:A total of six patients with heterotopic pancreas,as confirmed by clinical pathology and immunohistochemistry in the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University,Shanghai,China,were included.Nonenhanced CT and enhanced CT scanning were performed,and the resulting images were reviewed and analyzed using threedimensional postprocessing software,including CTVE.RESULTS:Four males and two females were enrolled.Several heterotopic pancreas sites were involved;three occurred in the stomach,including the gastric antrum(n =2)and lesser curvature(n=1),and two were in the duodenal bulb.Only one case of heterotopic pancreas lesion occurred in the mesentery.Four cases had a solid yet soft tissue density that had a homogeneous pattern when viewed by enhanced CT.Additionally,their CT values were similar to that of the pancreas.The ducts of the heterotopic pancreas tissue,one of the characteristic CT features of heterotopic pancreas tissue,were detected in the CT images of two patients.CTVE images showed normal mucosa around the tissue,which is also an important indicator of a heterotopic pancreas.However,none of the CTVE images showed the typical signs of central dimpling or umbilication.CONCLUSION:CT,enhanced CT and CTVE techniques provide useful information about the location,growth pattern,vascularity,and condition of the gastrointestinal wall around heterotopic pancreatic tissue.展开更多
Technological breakthroughs have advanced the temporal and spatial resolutions of diagnostic imaging, and 3 dimensional (3-D) reconstruction techniques have been introduced into everyday clinical practice. Virtual e...Technological breakthroughs have advanced the temporal and spatial resolutions of diagnostic imaging, and 3 dimensional (3-D) reconstruction techniques have been introduced into everyday clinical practice. Virtual endoscopy (VE) is a non-invasive technique that amplifies the perception of cross-sectional images in the 3-D space, providing precise spatial relationships of pathological regions and their surrounding structures. A variety of computer algorithms can be used to generate 3-D images, taking advantage of the information inherent in either spiral computed tomography or magnetic resonance imaging (MRI). VE images enable endoluminal navigation through hollow organs, thus simulating conventional endoscopy. Several clinical studies have validated the diagnostic utility of virtual cystoscopy, which has high sensitivity and specificity rates in the detection of bladder tumor. Published experience in the virtual exploration of the renal pelvis, ureter and urethra is encouraging but still scarce. VE is a safe, non-invasive method that could be applied in the long-term follow-up of patients with ureteropelvic junction obstruction, urinary bladder tumors and ureteral and/or urethral strictures. Its principal limitations are the inability to provide biopsy tissue specimens for histopathologic examination and the associated ionizing radiation hazards (unless MR/is used). However, in the case of endoluminal stenosis or obstruction, VE permits virtual endoluminal navigation both cephalad and caudal to the stenotic segment. To conclude, VE provides a less invasive method of evaluating the urinary tract, especially for clinicians who are less familiar with cross-sectional imaging than radiologists. (Asian J Androl 2006 Jan; 8: 31-38)展开更多
AIM: To present our initial experience regarding the feasibility of ultrasound virtual endoscopy(USVE) and its measurement reliability for polyp detection in an in vitro study using pig intestine specimens.METHODS: Si...AIM: To present our initial experience regarding the feasibility of ultrasound virtual endoscopy(USVE) and its measurement reliability for polyp detection in an in vitro study using pig intestine specimens.METHODS: Six porcine intestine specimens containing 30 synthetic polyps underwent USVE, computed tomography colonography(CTC) and optical colonoscopy(OC) for polyp detection. The polyp measurement defined as the maximum polyp diameter on twodimensional(2D) multiplanar reformatted(MPR) planes was obtained by USVE, and the absolute measurement error was analyzed using the direct measurement as the reference standard.RESULTS: USVE detected 29(96.7%) of 30 polyps, remaining a 7-mm one missed. There was one falsepositive finding. Twenty-six(89.7%) of 29 reconstructedimages were clearly depicted, while 29(96.7%) of 30 polyps were displayed on CTC with one false-negative finding. In OC, all the polyps were detected. The intraclass correlation coefficient was 0.876(95%CI: 0.745-0.940) for measurements obtained with USVE. The pooled absolute measurement errors ± the standard deviations of the depicted polyps with actual sizes ≤ 5 mm, 6-9 mm, and ≥ 10 mm were 1.9 ± 0.8 mm, 0.9 ± 1.2 mm, and 1.0 ± 1.4 mm, respectively.CONCLUSION: USVE is reliable for polyp detection and measurement in in vitro study.展开更多
Although computer capabilities have been improved significantly, a large-scale virtual reality (VR) system demands much more in terms of memory and computation than the current computer systems can offer. This paper...Although computer capabilities have been improved significantly, a large-scale virtual reality (VR) system demands much more in terms of memory and computation than the current computer systems can offer. This paper discusses two important issues related to VR performance and applications in building navigation. These are dynamic loading of models based on cell segmentation for the optimal VR operation, and the route optimization based on path planning for easy navigation. The VR model of engineering and information technology complex (EITC) building at the University of Manitoba is built as an example to show the feasibility of the proposed methods. The reality, enhanced by three-dimensional (3D) real-time interactivity and visualization, leads navigators into a state of the virtual building immersion.展开更多
Objective:Training young physicians in gastrointestinal endoscopy through virtual reality(VR)simulators has become popular.It is important to evaluate the benefits and usefulness of this technology for teaching endosc...Objective:Training young physicians in gastrointestinal endoscopy through virtual reality(VR)simulators has become popular.It is important to evaluate the benefits and usefulness of this technology for teaching endoscopic skills.The objective of this literature review is to understand the benefits of VR technology through quantitative and qualitative examination of learning outcomes.Methods:A literature search of 7 databases was conducted.Studies which compared the effects of learning through VR simulation and another method of learning were included.In addition,studies were included if they evaluated learning outcomes on clinical patients.Participants could be medical residents,fellows,physicians,or nurses.Common outcomes measured across studies included subjective overall performance scores,total procedure times,rate of successful procedure completion,error rates,patient pain or discomfort,and measures of independence.Results:A total of 22 studies were included.Overall,VR simulation training was seen to be comparable or significantly better than clinical training,no training,other types of simulation,and another form of VR training.Many authors reported increasing patient safety,reducing stress and time constraints,and shortening the learning curve as advantages of VR simulation training.However,this form of training is also expensive and may result in the learning of bad habits.Conclusion:VR simulation technology can be a valuable form of educating endoscopy novices if properly supervised during training,and if there is also integration of clinical training.展开更多
Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern...Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.展开更多
Objective To explore the value of computed tomography virtual endoscopy(VE) in assessing ossicular chain disruption in temporal bone fracture and ear trauma with intact tympanum. Methods High resolution spiral compute...Objective To explore the value of computed tomography virtual endoscopy(VE) in assessing ossicular chain disruption in temporal bone fracture and ear trauma with intact tympanum. Methods High resolution spiral computerized tomography(CT) was completed in 35 cases of temporal bone fracture and 5 cases of tympanum trauma, all with intact or healed tympanum. Three-dimensional reconstruction was completed using a virtual endoscopy software. Audiological tests were conducted in all patients and evaluation of facial nerve injury in patients with facial paralysis. Patients with mild conductive deafness, ossicular chain subluxation on VE, and no facial paralysis were treated conservatively for 4-12 weeks with repeated hearing evaluation; those with facial paralysis underwent surgery if no recovery after 4- 8 weeks of conservative treatment. Patients with moderate to severe conductive hearing loss or mixed hearing loss, incus long process fracture or dislocation on VE and facial paralysis, underwent ossicular chain reconstruction and facial nerve decompression after conservative treatment for 4-8 weeks, or exploratory tympanotomy only if no facial paralysis. VE, audiological tests and facial nerve function tests were repeated in 3-6 months after surgery. Results Of the 6 cases with mild conductive hearing loss, ossicular chain subluxation and no facial paralysis, 3recovered to normal hearing spontaneously and 3 showed no significant improvement, after 4-12 weeks of conservative treatment. After conservative treatment for 4-8 weeks, 3 of the 12 cases with mild conductive deafness, ossicular chain dislocation on VE and facial paralysis recovered to normal hearing and HouseBrackmann(HB) grade I facial function from HB grade II,4 showed facial function recovery to HB grade I(n=2) or II(n=2) from HB grade III but no hearing recovery, and 5 gained no recovery and went on to receive exploratory tympanotomy and facial nerve decompression. The 11 cases with moderate to severe conductive deafness, incus long process fracture or dislocation on VE and facial paralysis all received ossicular chain reconstruction and facial nerve decompression after 4-8 weeks of conservative treatment. The 7 cases with moderate to severe conductive deafness, dislocated or fallen incus on VE but no facial paralysis received ossicular chain reconstruction after conservative treatment. The 4 cases with mixed hearing loss, dislocated or fallen incus on VE and no facial paralysis received ossicular chain repair via the intact canal wall epitympanum approach after conservative treatment. Pharmacological therapies continued postoperatively in these patients to treat sensorineural deafness. Although temporal bone CT scans displayed the fracture line and malleus/incus abnormalities, VE provided additional detailed information on dislocation of incudomalleal and incudostapedial joints, incus dislocation or fracture, separation between crus longum incudis and stapes, and incus shifting. These were all confirmed during surgery. VE results and surgery findings were 100% consistent in patients with ossicular chain disruption. Conclusion VE can provide reliable visual evidence for accurate assessment of traumatic ossicular chain disruption, timing of surgery and individualizing surgical strategies and postoperative follow-up.展开更多
Type Ⅳ-A choledochal cysts (CCs) are a congenital biliary anomaly which involve dilatation of the extrahepatic and intrahepatic bile ducts. We present the case of a 30-year-old woman with type Ⅳ-A CC, on whom threed...Type Ⅳ-A choledochal cysts (CCs) are a congenital biliary anomaly which involve dilatation of the extrahepatic and intrahepatic bile ducts. We present the case of a 30-year-old woman with type Ⅳ-A CC, on whom threedimensional computed tomography (3D CT) and virtual endoscopy were performed. 3D CT revealed partial dilatation in the posterior branch of the intrahepatic bile duct and a relative stricture between it and the extrahepatic bile duct. Virtual endoscopy showed that this stricture was membrane-like and separated from the surrounding blood vessels. Based on these image findings, complete cyst resection, bile duct plasty for the stricture, and hepaticojejunostomy were safely performed. To the best of our knowledge, there are no reports of imaging by virtual endoscopy of the biliary tract which show the surrounding blood vessels running along the bile duct.展开更多
AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single ce...AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.展开更多
文摘BACKGROUND Virtual reality(VR)has emerged as an innovative technology in endoscopy training,providing a simulated environment that closely resembles real-life scenarios and offering trainees a valuable platform to acquire and enhance their endoscopic skills.This systematic review will critically evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.AIM To evaluate the effectiveness and feasibility of VR-based training compared to traditional methods.By examining the current state of the field,this review seeks to identify gaps,challenges,and opportunities for further research and implementation of VR in endoscopic training.METHODS The study is a systematic review,following the guidelines for reporting systematic reviews set out by the PRISMA statement.A comprehensive search command was designed and implemented and run in September 2023 to identify relevant studies available,from electronic databases such as PubMed,Scopus,Cochrane,and Google Scholar.The results were systematically reviewed.RESULTS Sixteen articles were included in the final analysis.The total number of participants was 523.Five studies focused on both upper endoscopy and colonoscopy training,two on upper endoscopy training only,eight on colonoscopy training only,and one on sigmoidoscopy training only.Gastrointestinal Mentor virtual endoscopy simulator was commonly used.Fifteen reported positive results,indicating that VR-based training was feasible and acceptable for endoscopy learners.VR technology helped the trainees enhance their skills in manipulating the endoscope,reducing the procedure time or increasing the technical accuracy,in VR scenarios and real patients.Some studies show that the patient discomfort level decreased significantly.However,some studies show there were no significant differences in patient discomfort and pain scores between VR group and other groups.CONCLUSION VR training is effective for endoscopy training.There are several well-designed randomized controlled trials with large sample sizes,proving the potential of this innovative tool.Thus,VR should be more widely adopted in endoscopy training.Furthermore,combining VR training with conventional methods could be a promising approach that should be implemented in training.
文摘Background Currently,many simulator systems for medical procedures are under development.These systems can provide new solutions for training,planning,and testing medical practices,improve performance,and optimize the time of the exams.However,to achieve the best results,certain premises must be followed and applied to the model under development,such as usability,control,graphics realism,and interactive and dynamic gami-fication.Methods This study presents a system for simulating a medical examination procedure in the nasal cavity for training and research purposes,using a patient′s accurate computed tomography(CT)as a reference.The pathologies that are used as a guide for the development of the system are highlighted.Furthermore,an overview of current studies covering bench medical mannequins,3D printing,animals,hardware,software,and software that use hardware to boost user interaction,is given.Finally,a comparison with similar state-of-the-art studies is made.Results The main result of this work is interactive gamification techniques to propose an experience of simulation of an immersive exam by identifying pathologies present in the nasal cavity such as hypertrophy of turbinates,septal deviation adenoid hypertrophy,nasal polyposis,and tumor.
文摘Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.
文摘BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE overlaps with severe portal hypertensive gastropathy(PHG).AIM To determine the added diagnostic value of virtual chromoendoscopy to high definition white light for real-time endoscopic diagnosis of GAVE and PHG.METHODS We developed an I-scan virtual chromoendoscopy criteria for diagnosis of GAVE and PHG.We tested our criteria in a cross-sectional cohort of cirrhotic adults with GAVE and PHG when high-definition white light endoscopy(HDWLE)diagnosis was in doubt.We then compared the accuracy of I-scan vs HDWLE alone to histology.RESULTS Twenty-three patients were included in this study(65.2%Caucasians and 60.9%males).Chronic hepatitis C was the predominant cause of cirrhosis(43.5%)and seven adults(30.4%)had confirmed GAVE on histology.I-scan had higher sensitivity(100%vs 85.7%)and specificity(75%vs 62.5%)in diagnosing GAVE compared to HDWLE.This translates into a higher,albeit not statistically significant,accuracy of I-scan in detecting GAVE compared to HDWLE alone(82%vs 70%).I-scan was less likely to lead to an accurate diagnosis of GAVE in patients on dialysis(P<0.05)and in patients with elevated creatinine(P<0.05).Iscan had similar accuracy to HDWLE in detecting PHG.CONCLUSION This pilot work supports that virtual chromoendoscopy may obviate the need for biopsies when the presence of GAVE is in doubt.Larger studies are needed to assess the impact of virtual chromoendoscopy on success of endoscopic therapy for GAVE.
文摘The use of simulators as educational tools for medical procedures is spreading rapidly and many efforts have been made for their implementation in gastrointestinal endoscopy training. Endoscopy simulation training has been suggested for ascertaining patient safety while positively influencing the trainees' learning curve. Virtual simulators are the most promising tool among all available types of simulators. These integrated modalities offer a human-like endoscopy experience by combining virtual images of the gastrointestinal tract and haptic realism with using a customized endoscope. From their first steps in the 1980s until today, research involving virtual endoscopic simulators can be divided in two categories: investigation of the impact of virtual simulator training in acquiring endoscopy skills and measuring competence. Emphasis should also be given to the financial impact of their implementation in endoscopy, including the cost of these state-of-theart simulators and the potential economic benefits from their usage. Advances in technology will contribute to the upgrade of existing models and the development of new ones; while further research should be carried out to discover new fields of application.
文摘AIM:To present our experience of using 3D virtual intravascular endoscopy(VIE) to characterize and evaluate the intraluminal appearances of aortic dissection.METHODS:Ten patients with known aortic dissection underwent dual-source computed tomography angiography and were included in the study.In addition to 2D axial and multiplanar reformatted images as well as 3D reconstructions,VIE images were created in each patient to demonstrate intraluminal views of the aorta and its branches,origin of artery branches and artery branch involvement by aortic dissection.RESULTS:Stanford A dissection was found in 8 patients and B dissection in the remaining 2 patients.VIE images were successfully generated in all of the patients with excellent visualization of the normal anatomical structures,intimal flap and intimal entrance tear,communication between true and false lumens,as well as assessment of the extent of aortic dissection.CONCLUSION:Our preliminary experience suggests that VIE could be used as a complementary tool to assist radiologists accurately evaluate aortic dissection so that better patient management can be achieved.
基金Supported by Science and Technology Commission of Shanghai Municipality,Grant No.08411951200
文摘AIM:To improve the diagnosis of heterotopic pancreas by the use of contrastenhanced computed tomography(CT)imaging and CT virtual endoscopy(CTVE).METHODS:A total of six patients with heterotopic pancreas,as confirmed by clinical pathology and immunohistochemistry in the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University,Shanghai,China,were included.Nonenhanced CT and enhanced CT scanning were performed,and the resulting images were reviewed and analyzed using threedimensional postprocessing software,including CTVE.RESULTS:Four males and two females were enrolled.Several heterotopic pancreas sites were involved;three occurred in the stomach,including the gastric antrum(n =2)and lesser curvature(n=1),and two were in the duodenal bulb.Only one case of heterotopic pancreas lesion occurred in the mesentery.Four cases had a solid yet soft tissue density that had a homogeneous pattern when viewed by enhanced CT.Additionally,their CT values were similar to that of the pancreas.The ducts of the heterotopic pancreas tissue,one of the characteristic CT features of heterotopic pancreas tissue,were detected in the CT images of two patients.CTVE images showed normal mucosa around the tissue,which is also an important indicator of a heterotopic pancreas.However,none of the CTVE images showed the typical signs of central dimpling or umbilication.CONCLUSION:CT,enhanced CT and CTVE techniques provide useful information about the location,growth pattern,vascularity,and condition of the gastrointestinal wall around heterotopic pancreatic tissue.
文摘Technological breakthroughs have advanced the temporal and spatial resolutions of diagnostic imaging, and 3 dimensional (3-D) reconstruction techniques have been introduced into everyday clinical practice. Virtual endoscopy (VE) is a non-invasive technique that amplifies the perception of cross-sectional images in the 3-D space, providing precise spatial relationships of pathological regions and their surrounding structures. A variety of computer algorithms can be used to generate 3-D images, taking advantage of the information inherent in either spiral computed tomography or magnetic resonance imaging (MRI). VE images enable endoluminal navigation through hollow organs, thus simulating conventional endoscopy. Several clinical studies have validated the diagnostic utility of virtual cystoscopy, which has high sensitivity and specificity rates in the detection of bladder tumor. Published experience in the virtual exploration of the renal pelvis, ureter and urethra is encouraging but still scarce. VE is a safe, non-invasive method that could be applied in the long-term follow-up of patients with ureteropelvic junction obstruction, urinary bladder tumors and ureteral and/or urethral strictures. Its principal limitations are the inability to provide biopsy tissue specimens for histopathologic examination and the associated ionizing radiation hazards (unless MR/is used). However, in the case of endoluminal stenosis or obstruction, VE permits virtual endoluminal navigation both cephalad and caudal to the stenotic segment. To conclude, VE provides a less invasive method of evaluating the urinary tract, especially for clinicians who are less familiar with cross-sectional imaging than radiologists. (Asian J Androl 2006 Jan; 8: 31-38)
基金Supported by The National Natural Science Foundation of China,No.81271576
文摘AIM: To present our initial experience regarding the feasibility of ultrasound virtual endoscopy(USVE) and its measurement reliability for polyp detection in an in vitro study using pig intestine specimens.METHODS: Six porcine intestine specimens containing 30 synthetic polyps underwent USVE, computed tomography colonography(CTC) and optical colonoscopy(OC) for polyp detection. The polyp measurement defined as the maximum polyp diameter on twodimensional(2D) multiplanar reformatted(MPR) planes was obtained by USVE, and the absolute measurement error was analyzed using the direct measurement as the reference standard.RESULTS: USVE detected 29(96.7%) of 30 polyps, remaining a 7-mm one missed. There was one falsepositive finding. Twenty-six(89.7%) of 29 reconstructedimages were clearly depicted, while 29(96.7%) of 30 polyps were displayed on CTC with one false-negative finding. In OC, all the polyps were detected. The intraclass correlation coefficient was 0.876(95%CI: 0.745-0.940) for measurements obtained with USVE. The pooled absolute measurement errors ± the standard deviations of the depicted polyps with actual sizes ≤ 5 mm, 6-9 mm, and ≥ 10 mm were 1.9 ± 0.8 mm, 0.9 ± 1.2 mm, and 1.0 ± 1.4 mm, respectively.CONCLUSION: USVE is reliable for polyp detection and measurement in in vitro study.
基金supported by Discovery Grants of National Science and Engineering Research Council of Canada (NSERC) and Faculty of Engineering at University of Manitoba
文摘Although computer capabilities have been improved significantly, a large-scale virtual reality (VR) system demands much more in terms of memory and computation than the current computer systems can offer. This paper discusses two important issues related to VR performance and applications in building navigation. These are dynamic loading of models based on cell segmentation for the optimal VR operation, and the route optimization based on path planning for easy navigation. The VR model of engineering and information technology complex (EITC) building at the University of Manitoba is built as an example to show the feasibility of the proposed methods. The reality, enhanced by three-dimensional (3D) real-time interactivity and visualization, leads navigators into a state of the virtual building immersion.
文摘Objective:Training young physicians in gastrointestinal endoscopy through virtual reality(VR)simulators has become popular.It is important to evaluate the benefits and usefulness of this technology for teaching endoscopic skills.The objective of this literature review is to understand the benefits of VR technology through quantitative and qualitative examination of learning outcomes.Methods:A literature search of 7 databases was conducted.Studies which compared the effects of learning through VR simulation and another method of learning were included.In addition,studies were included if they evaluated learning outcomes on clinical patients.Participants could be medical residents,fellows,physicians,or nurses.Common outcomes measured across studies included subjective overall performance scores,total procedure times,rate of successful procedure completion,error rates,patient pain or discomfort,and measures of independence.Results:A total of 22 studies were included.Overall,VR simulation training was seen to be comparable or significantly better than clinical training,no training,other types of simulation,and another form of VR training.Many authors reported increasing patient safety,reducing stress and time constraints,and shortening the learning curve as advantages of VR simulation training.However,this form of training is also expensive and may result in the learning of bad habits.Conclusion:VR simulation technology can be a valuable form of educating endoscopy novices if properly supervised during training,and if there is also integration of clinical training.
文摘Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.
基金This study was supported by Medical Research Fund Projects of Guangdong Province,Jinan University Scientific Research Opening Stock Project
文摘Objective To explore the value of computed tomography virtual endoscopy(VE) in assessing ossicular chain disruption in temporal bone fracture and ear trauma with intact tympanum. Methods High resolution spiral computerized tomography(CT) was completed in 35 cases of temporal bone fracture and 5 cases of tympanum trauma, all with intact or healed tympanum. Three-dimensional reconstruction was completed using a virtual endoscopy software. Audiological tests were conducted in all patients and evaluation of facial nerve injury in patients with facial paralysis. Patients with mild conductive deafness, ossicular chain subluxation on VE, and no facial paralysis were treated conservatively for 4-12 weeks with repeated hearing evaluation; those with facial paralysis underwent surgery if no recovery after 4- 8 weeks of conservative treatment. Patients with moderate to severe conductive hearing loss or mixed hearing loss, incus long process fracture or dislocation on VE and facial paralysis, underwent ossicular chain reconstruction and facial nerve decompression after conservative treatment for 4-8 weeks, or exploratory tympanotomy only if no facial paralysis. VE, audiological tests and facial nerve function tests were repeated in 3-6 months after surgery. Results Of the 6 cases with mild conductive hearing loss, ossicular chain subluxation and no facial paralysis, 3recovered to normal hearing spontaneously and 3 showed no significant improvement, after 4-12 weeks of conservative treatment. After conservative treatment for 4-8 weeks, 3 of the 12 cases with mild conductive deafness, ossicular chain dislocation on VE and facial paralysis recovered to normal hearing and HouseBrackmann(HB) grade I facial function from HB grade II,4 showed facial function recovery to HB grade I(n=2) or II(n=2) from HB grade III but no hearing recovery, and 5 gained no recovery and went on to receive exploratory tympanotomy and facial nerve decompression. The 11 cases with moderate to severe conductive deafness, incus long process fracture or dislocation on VE and facial paralysis all received ossicular chain reconstruction and facial nerve decompression after 4-8 weeks of conservative treatment. The 7 cases with moderate to severe conductive deafness, dislocated or fallen incus on VE but no facial paralysis received ossicular chain reconstruction after conservative treatment. The 4 cases with mixed hearing loss, dislocated or fallen incus on VE and no facial paralysis received ossicular chain repair via the intact canal wall epitympanum approach after conservative treatment. Pharmacological therapies continued postoperatively in these patients to treat sensorineural deafness. Although temporal bone CT scans displayed the fracture line and malleus/incus abnormalities, VE provided additional detailed information on dislocation of incudomalleal and incudostapedial joints, incus dislocation or fracture, separation between crus longum incudis and stapes, and incus shifting. These were all confirmed during surgery. VE results and surgery findings were 100% consistent in patients with ossicular chain disruption. Conclusion VE can provide reliable visual evidence for accurate assessment of traumatic ossicular chain disruption, timing of surgery and individualizing surgical strategies and postoperative follow-up.
文摘Type Ⅳ-A choledochal cysts (CCs) are a congenital biliary anomaly which involve dilatation of the extrahepatic and intrahepatic bile ducts. We present the case of a 30-year-old woman with type Ⅳ-A CC, on whom threedimensional computed tomography (3D CT) and virtual endoscopy were performed. 3D CT revealed partial dilatation in the posterior branch of the intrahepatic bile duct and a relative stricture between it and the extrahepatic bile duct. Virtual endoscopy showed that this stricture was membrane-like and separated from the surrounding blood vessels. Based on these image findings, complete cyst resection, bile duct plasty for the stricture, and hepaticojejunostomy were safely performed. To the best of our knowledge, there are no reports of imaging by virtual endoscopy of the biliary tract which show the surrounding blood vessels running along the bile duct.
文摘AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.