AIM: To retrospectively compare previous-day vs splitdose preparation in terms of bowel cleanliness and polyp detection in patients referred for polypectomy. METHODS: Fifty patients underwent two colonoscopies: one di...AIM: To retrospectively compare previous-day vs splitdose preparation in terms of bowel cleanliness and polyp detection in patients referred for polypectomy. METHODS: Fifty patients underwent two colonoscopies: one diagnostic in a private clinic and a second for polypectomy in a University Hospital. The latter procedures were performed within 12 wk of the index ones. Examinations were accomplished by two experienced endoscopists, different in each facility. Twenty-seven patients underwent screening/surveillance colonoscopy, while the rest were symptomatic. Previous day bowel preparation was utilized initially and splitdose for polypectomy. Colon cleansing was evaluated using the Aronchick scale. We measured the number of detected polyps, and the polyp miss rates per-polyp.RESULTS: Excellent/good preparation was reported in 38 cases with previous-day preparation(76%) vs 46 with split-dose(92%), respectively(P = 0.03). One hundred and twenty-six polyps were detected initially and 169 subsequently(P < 0.0001); 88 vs 126 polyps were diminutive(P < 0.0001), 25 vs 29 small(P = 0.048) and 13 vs 14 equal or larger than 10 mm. The miss rates for total, diminutive, small and large polyps were 25.4%, 30.1%, 13.7% and 6.6%, respectively. Multivariate analysis revealed that split-dose preparation was significantly associated(OR, P) with increased number of polyps detected overall(0.869, P < 0.001), in the right(0.418, P = 0.008) and in the left colon(0.452, P = 0.02). CONCLUSION: Split-dose preparation improved colon cleansing, enhanced polyp detection and unmasked significant polyp miss rates.展开更多
In this paper, we discuss quality of service requirements and impacts of different workloads of each service class on the resource proportion allocation scheme, and formulize the problem of minimizing the quality of s...In this paper, we discuss quality of service requirements and impacts of different workloads of each service class on the resource proportion allocation scheme, and formulize the problem of minimizing the quality of service miss rate of service requests by using the queuing theory. The optimally allocating resource proportion scheme is obtained by the Lagrangian optimization approach. Our simulation results show that our scheme is efficient.展开更多
AIM:To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized,controlled trial data.METHODS:The Third Eye Retroscope Randomized Clinical Evaluation...AIM:To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized,controlled trial data.METHODS:The Third Eye Retroscope Randomized Clinical Evaluation(TERRACE) was a randomized,controlled,multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope's forward view.We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device.Subjects were patients scheduled for colonoscopy for screening,surveillance or diagnostic workup,and each underwent same-day tandem examinations with standard colonoscopy(SC) and Third Eye colonoscopy(TEC),randomized to SC followed by TEC or vice versa.RESULTS:Indication for colonoscopy was screening in 176/345 subjects(51.0%),surveillance after previous polypectomy in 87(25.2%) and diagnostic workup in 82(23.8%).In 4 subjects no indication was specified.Previously reported overall results had shown a net additional adenoma detection rate(ADR) with TEC of 23.2% compared to SC.Relative risk(RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92(P = 0.029).Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening,35.7% for surveillance,55.4% for diagnostic and 40.7% for surveillance and diagnostic combined.The RR of missing adenomas with SC vs TEC was 1.11(P = 0.815) for screening,3.15(P = 0.014) for surveillance,8.64(P = 0.039) for diagnostic and 3.34(P = 0.003) for surveillance and diagnostic combined.Although a multivariate Poisson regression suggested gender as a possibly significant factor,subset analysis showed that the difference between genders was not statistically significant.Age,bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC.Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm,respectively(P = NS).CONCLUSION:TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup,but not in screening patients(ClinicalTrials.gov Identifier:NCT01044732).展开更多
AIM:To characterize small bowel(SB)tumors detected by capsule endoscopy(CE),and identify missed tumors.METHODS:The study included 145 consecutive patients in whom 150 CEs were performed.Following CE,the medical record...AIM:To characterize small bowel(SB)tumors detected by capsule endoscopy(CE),and identify missed tumors.METHODS:The study included 145 consecutive patients in whom 150 CEs were performed.Following CE,the medical records of the study population were reviewed.Results of double-or single-balloon enteroscopy performed after CE and the results of surgery in all patients operated on were retrieved.The patients were contacted through telephone interviews or postal mail.In addition,the national cancer registry and the polish clinical gastrointestinal stromal tumor(GIST)Registry were searched to identify missed neoplasms.RESULTS:Indications for CE included overt and occult obscure gastrointestinal bleeding(n=81,53.7%),anemia(n=19,12.7%),malabsorption(n=18,12%),abnormal CB follow through(n=9,6%),abdominal pain(n=7,5%),celiac disease(n=5,3%),neuroendocrine tumor(n=3,2%),Crohn’s disease(n=2,<2%),Peutz-Jeghers syndrome(n=2,<2%),other polyposes(n=2,<2%),and diarrhea(n=2,<2%).The capsule reached the colon in 115(76.6%)examinations.In 150 investigations,CE identified 15SB tumors(10%),14 of which were operated on or treated endoscopically.Malignancies included metastatic melanoma(n=1),adenocarcinoma(n=2),and GIST(n=3).Benign neoplasms included dysplastic Peutz-Jeghers polyps(n=4).Non-neoplastic masses included venous malformation(n=1),inflammatory tumors(n=2),and a mass of unknown histology(n=1).During the follow-up period,three additional SB tumors were found(2 GISTs and one mesenteric tumor of undefined nature).The National Cancer Registry and Polish Clinical GIST Registry revealed no additional SB neoplasms in the post-examination period(follow-up:range 4.2-102.5 mo,median 39 mo).The sensitivity of CE for tumor detection was 83.3%,and the negative predictive value was 97.6%.The specificity and positive predictive value were both 100%.CONCLUSION:Neoplasms may be missed by CE,especially in the proximal SB.In overt obscure gastrointestinal bleeding,complementary endoscopic and/or radiologic diagnostic tests are indicated.展开更多
In writings on relativity time, the various relations are only changed by the transverse shift. This paper proves that the axial Doppler shift does that as well and gives some impacts of that on common differential re...In writings on relativity time, the various relations are only changed by the transverse shift. This paper proves that the axial Doppler shift does that as well and gives some impacts of that on common differential relations in physics. When a modulated signal lasting a time = T is subjected to an optical Doppler shift K (either axial or transverse or both), where K is shifted frequency/original frequency, the Doppler shifted signal will last T/K. This because all shifted harmonics of its Fourier series (with a fundamental period of T) will last 1/K times the period of the original harmonic. The reader can graph any Fourier series and then graph its shifted series. The reader will see the shifted period is T/K. The Fourier series of the original repeats when time is greater than T and the shifted one when time is greater than T/K, which means the original series only represents the signal from time = 0 to T and the shifted series represents the shifted signal from time = 0 to T/K. Hence, the shifted one has all of the information in T/K as the original has in T. Therefore everything in the series including information is T/K long in the shifted series. Therefore, both the axial and the transverse Doppler shift change time periods in a vacuum, independent of material involved. That has not been obvious for over 100 years the axial shift changes time from the definition of frequency = 1/time.展开更多
文摘AIM: To retrospectively compare previous-day vs splitdose preparation in terms of bowel cleanliness and polyp detection in patients referred for polypectomy. METHODS: Fifty patients underwent two colonoscopies: one diagnostic in a private clinic and a second for polypectomy in a University Hospital. The latter procedures were performed within 12 wk of the index ones. Examinations were accomplished by two experienced endoscopists, different in each facility. Twenty-seven patients underwent screening/surveillance colonoscopy, while the rest were symptomatic. Previous day bowel preparation was utilized initially and splitdose for polypectomy. Colon cleansing was evaluated using the Aronchick scale. We measured the number of detected polyps, and the polyp miss rates per-polyp.RESULTS: Excellent/good preparation was reported in 38 cases with previous-day preparation(76%) vs 46 with split-dose(92%), respectively(P = 0.03). One hundred and twenty-six polyps were detected initially and 169 subsequently(P < 0.0001); 88 vs 126 polyps were diminutive(P < 0.0001), 25 vs 29 small(P = 0.048) and 13 vs 14 equal or larger than 10 mm. The miss rates for total, diminutive, small and large polyps were 25.4%, 30.1%, 13.7% and 6.6%, respectively. Multivariate analysis revealed that split-dose preparation was significantly associated(OR, P) with increased number of polyps detected overall(0.869, P < 0.001), in the right(0.418, P = 0.008) and in the left colon(0.452, P = 0.02). CONCLUSION: Split-dose preparation improved colon cleansing, enhanced polyp detection and unmasked significant polyp miss rates.
文摘In this paper, we discuss quality of service requirements and impacts of different workloads of each service class on the resource proportion allocation scheme, and formulize the problem of minimizing the quality of service miss rate of service requests by using the queuing theory. The optimally allocating resource proportion scheme is obtained by the Lagrangian optimization approach. Our simulation results show that our scheme is efficient.
基金Supported by A grant from Avantis Medical Systems,in part
文摘AIM:To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized,controlled trial data.METHODS:The Third Eye Retroscope Randomized Clinical Evaluation(TERRACE) was a randomized,controlled,multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope's forward view.We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device.Subjects were patients scheduled for colonoscopy for screening,surveillance or diagnostic workup,and each underwent same-day tandem examinations with standard colonoscopy(SC) and Third Eye colonoscopy(TEC),randomized to SC followed by TEC or vice versa.RESULTS:Indication for colonoscopy was screening in 176/345 subjects(51.0%),surveillance after previous polypectomy in 87(25.2%) and diagnostic workup in 82(23.8%).In 4 subjects no indication was specified.Previously reported overall results had shown a net additional adenoma detection rate(ADR) with TEC of 23.2% compared to SC.Relative risk(RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92(P = 0.029).Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening,35.7% for surveillance,55.4% for diagnostic and 40.7% for surveillance and diagnostic combined.The RR of missing adenomas with SC vs TEC was 1.11(P = 0.815) for screening,3.15(P = 0.014) for surveillance,8.64(P = 0.039) for diagnostic and 3.34(P = 0.003) for surveillance and diagnostic combined.Although a multivariate Poisson regression suggested gender as a possibly significant factor,subset analysis showed that the difference between genders was not statistically significant.Age,bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC.Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm,respectively(P = NS).CONCLUSION:TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup,but not in screening patients(ClinicalTrials.gov Identifier:NCT01044732).
基金Supported by The Polish Foundation for Gastroenterology
文摘AIM:To characterize small bowel(SB)tumors detected by capsule endoscopy(CE),and identify missed tumors.METHODS:The study included 145 consecutive patients in whom 150 CEs were performed.Following CE,the medical records of the study population were reviewed.Results of double-or single-balloon enteroscopy performed after CE and the results of surgery in all patients operated on were retrieved.The patients were contacted through telephone interviews or postal mail.In addition,the national cancer registry and the polish clinical gastrointestinal stromal tumor(GIST)Registry were searched to identify missed neoplasms.RESULTS:Indications for CE included overt and occult obscure gastrointestinal bleeding(n=81,53.7%),anemia(n=19,12.7%),malabsorption(n=18,12%),abnormal CB follow through(n=9,6%),abdominal pain(n=7,5%),celiac disease(n=5,3%),neuroendocrine tumor(n=3,2%),Crohn’s disease(n=2,<2%),Peutz-Jeghers syndrome(n=2,<2%),other polyposes(n=2,<2%),and diarrhea(n=2,<2%).The capsule reached the colon in 115(76.6%)examinations.In 150 investigations,CE identified 15SB tumors(10%),14 of which were operated on or treated endoscopically.Malignancies included metastatic melanoma(n=1),adenocarcinoma(n=2),and GIST(n=3).Benign neoplasms included dysplastic Peutz-Jeghers polyps(n=4).Non-neoplastic masses included venous malformation(n=1),inflammatory tumors(n=2),and a mass of unknown histology(n=1).During the follow-up period,three additional SB tumors were found(2 GISTs and one mesenteric tumor of undefined nature).The National Cancer Registry and Polish Clinical GIST Registry revealed no additional SB neoplasms in the post-examination period(follow-up:range 4.2-102.5 mo,median 39 mo).The sensitivity of CE for tumor detection was 83.3%,and the negative predictive value was 97.6%.The specificity and positive predictive value were both 100%.CONCLUSION:Neoplasms may be missed by CE,especially in the proximal SB.In overt obscure gastrointestinal bleeding,complementary endoscopic and/or radiologic diagnostic tests are indicated.
文摘In writings on relativity time, the various relations are only changed by the transverse shift. This paper proves that the axial Doppler shift does that as well and gives some impacts of that on common differential relations in physics. When a modulated signal lasting a time = T is subjected to an optical Doppler shift K (either axial or transverse or both), where K is shifted frequency/original frequency, the Doppler shifted signal will last T/K. This because all shifted harmonics of its Fourier series (with a fundamental period of T) will last 1/K times the period of the original harmonic. The reader can graph any Fourier series and then graph its shifted series. The reader will see the shifted period is T/K. The Fourier series of the original repeats when time is greater than T and the shifted one when time is greater than T/K, which means the original series only represents the signal from time = 0 to T and the shifted series represents the shifted signal from time = 0 to T/K. Hence, the shifted one has all of the information in T/K as the original has in T. Therefore everything in the series including information is T/K long in the shifted series. Therefore, both the axial and the transverse Doppler shift change time periods in a vacuum, independent of material involved. That has not been obvious for over 100 years the axial shift changes time from the definition of frequency = 1/time.
