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Sample records for ct virtual colonoscopy

  1. Virtual colonoscopy

    Science.gov (United States)

    Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

  2. Virtual colonoscopy.

    Science.gov (United States)

    Vining, D J

    1997-04-01

    A new method for colon examination, virtual colonoscopy, has been created by combining spiral computed tomography and virtual reality computer technology. If virtual colonoscopy proves equal to or superior to traditional colonoscopy in sensitivity and specificity for cancer screening, it would yield significant clinical and public health benefits because of its potential for increased acceptance among patients as well as its considerably lower cost and risks.

  3. Dual energy virtual CT colonoscopy with dual source computed tomography. Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Karcaaltincaba, M.; Karaosmanoglu, D.; Akata, D.; Sentuerk, S.; Oezmen, M. [Dept. of Radiology, Hacettepe Univ. School of Medicine (Turkey); Alibek, S. [Dept. of Radiology, Hacettepe Univ. School of Medicine (Turkey); Radiology Inst., Univ. of Erlangen (Germany)

    2009-09-15

    Purpose: To describe the technique of DE MDCT colonoscopy and to assess its feasibility. Materials and Methods: 8 patients were scanned with DSCT with a DE scan protocol and dose modulation software. Analysis was performed using dedicated DE software. Prone non-contrast images and DE supine images after contrast injection were obtained. Results: DE colonoscopic images were successfully obtained in 7 patients, but the FOV did not cover all colonic segments in 1 patient, thus resulting in a technical success rate was 87.5%. Streak artifacts were present in the pelvic region in 2 patients. Virtual unenhanced images and iodine map images were obtained for all patients. In 1 patient a polypoid non-enhancing structure was noted on the iodine map, and conventional colonoscopy revealed impacted stool. Enhancing rectal cancer in 1 patient was correctly shown on the iodine map. Iodine maps helped to differentiate stool fragments/retained fluid by the absence of enhancement when compared to prone CT images. The major advantage of DE colonoscopy was the lack of misregistration. Conclusion: DE MDCT colonoscopy is technically feasible and may obviate the need for unenhanced prone images. It may be possible to perform noncathartic DECT colonoscopy. The major limitation is the limited FOV of tube B. The dose should be optimized to reduce streak artifacts in the pelvic region. (orig.)

  4. Virtual colonoscopy in paediatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Carrascosa, Patricia [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez (B1602ABQ), Buenos Aires (Argentina)], E-mail: patriciacarrascosa@diagnosticomaipu.com.ar; Lopez, Elba Martin; Capunay, Carlos; Vallejos, Javier; Carrascosa, Jorge [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez (B1602ABQ), Buenos Aires (Argentina)

    2010-04-15

    Objective: To determine the usefulness of perspective-filet view for polypoid lesions in paediatric patients in comparison with conventional virtual colonoscopy (VC) analysis and optical colonoscopy. Methods: Sixty-one patients (mean age 5 years old) with a previous episode of rectal bleeding were studied using a 16 slices CT scanner. All patients underwent a colonic preparation. Two acquisitions were done in supine and prone positions with slices of 2 mm thickness; increment 1 mm, 30-50 mA; 90-120 kV. In a workstation an experienced radiologist reviewed images twice. The first read was done using the conventional virtual colonoscopy technique with the evaluation of two-dimensional (2D), three-dimensional (3D) and endoscopical images. Later, in a second session, perspective-filet view was used. It shows a 360 deg. unrolled visualization of the inner colon. The presence, size and location of the lesions were determined. A record of the reading time was made. Results: At per patient evaluation the conventional virtual colonoscopy analysis obtained a sensitivity of 86% and a specificity of 98%. The perspective-filet view obtained a sensitivity of 91% and a specificity of 99%. In the evaluation on a per lesion basis the conventional analysis had a sensitivity of 81% and a specificity of 88%. Perspective-filet view, had a sensitivity of 82% and specificity of 90%. The average total reading time using conventional colonoscopy technique was 18 {+-} 3 min, versus 4 {+-} 1 min using the perspective-filet view. Conclusion: Virtual colon dissection with perspective-filet view is more time-efficient than conventional virtual colonoscopy evaluation with correct correlation in results.

  5. Virtual colonoscopy. A practical guide. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, Philippe; Gryspeerdt, Stefaan (eds.) [Stedelijk Ziekenhuis Roeselare (Belgium). Dept. of Radiology

    2010-07-01

    Virtual colonoscopy, or CT colonography, is a rapidly evolving technique for the detection of tumoral lesions in the colon. It is now accepted by the American Cancer Society as a valuable screening tool for both colorectal cancer and its adenomatous precursor. Virtual colonoscopy requires state-of-the-art technique with rigorous preparation, colonic distension, and optimization of scanning parameters. Dedicated reading, analysis, and reporting of the data sets are mandatory. With contributions from a number of leaders in the field, this book addresses all the important issues relating to virtual colonoscopy. There is a particular focus on practical aspects: how to start virtual colonoscopy in your department, the regular preparation, the importance of fecal tagging, how to reduce the preparation, how to obtain optimal colonic distension, and the correct scanning parameters. Imaging characteristics and pitfalls are considered in detail, with an extensive pictorial review of difficult lesions; the importance of computer-aided diagnosis is also discussed. In this second edition the text has been updated with the latest study results and developments in technology and new illustrations have been included. This book will be invaluable to every radiologist seeking information on how to perform the exciting technique of virtual colonoscopy. (orig.)

  6. Computed tomographic colography and virtual colonoscopy.

    Science.gov (United States)

    Ahlquist, D A; Hara, A K; Johnson, C D

    1997-07-01

    CT colography (CTC) is a powerful new approach to imaging the colorectum and a promising screening tool for the detection of colorectal neoplasia. From data generated by a helical CT scan, CTC uses virtual reality technology to produce highly discriminant two- and three-dimensional images that permit a thorough and minimally invasive evaluation of the entire colorectum. A dynamic CTC display technique from the endoluminal perspective, called cf2virtual colonoscopy,cf1 simulates colonoscopy by "flying" through the three-dimensional colon image. CTC offers potential advantages in diagnostic performance, safety, and patient acceptance over current screening approaches. Although early data suggest excellent colorectal polyp detection rates, this nascent technology will require rigorous clinical investigation and further refinements to assess adequately its place in the endoscopist's armamentarium.

  7. CT Colonography (Virtual Colonoscopy)

    Science.gov (United States)

    ... passes through the body, recording an image on photographic film or a special image recording plate. Bones ... American College of Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise ...

  8. Comparison of virtual colonoscopy and colonoscopy in diagnosis of colorectal neoplasia

    Institute of Scientific and Technical Information of China (English)

    戴宁; 忻莹; 邹立秋; 王建国; 高敏; 章士正; 姒健敏

    2002-01-01

    The diagnostic value of virtual colonoscopy versus colon oscopy was compared in detection of colorectal neoplasia. Virtual colonoscopy wa s performed on 29 patients with suspected colorectal diseases, Results were comp ared with colonoscopy for each case. Virtual colonoscopy was successfully perfor med on each patient. All patients tolerated virtual colonoscopy well, had no com plications. All colorectal malignance were identified both by virtual colonoscop y and colonoscopy. Twenty-five polyps were detected with colonoscopy, whereas o n ly 16 polyps were defined by virtual colonoscopy. Detection rates of polyps grea ter than 1.0 cm,between 0.5-0.9 cm and less than 0.5 cm in size were 90%,62.5% a nd 28.6% respectively. Virtual colonoscopy is fast, minimally invasive and well tolerated. This technique is a valuable clinical method in diagnosis of colorect al malignance and polyps larger than 0.5 cm in size.

  9. 结肠阳性造影CT仿真肠镜对结肠息肉诊断价值%Comparison of positive contrast-enhanced CT virtual colonoscopy and electron colonoscopy for detecting colorectal polyps

    Institute of Scientific and Technical Information of China (English)

    刘欣; 孟志华; 刘尚忠; 方先来; 华璟

    2011-01-01

    Objective To evaluate the efficacy of contrast-enhanced CT virtual colonoscopy for detecting colorectal polyps.Methods 57 patients with suspected or confirmed colorectal polyps were enrolled in this study.All patients underwent electron colonoscopy (EC) after CT virtual colonoscopy (CTVC) with positive contrast.CTVC results were reviewed by radiologists and the EC by endoscopists.Results 90 and 125 polyps were detected by EC and CTVC respectively.Using EC as gold standard, the sensitivity and specificity of CTVC were 95.23% and 93.33%, respectively.90 polyps of greater than 0.3 cm in diameter were detected on EC compared with 93 on CTVC with correlation rate of 86.67%.The false positive rate of CTVC was 16.67% with false negative rate of 13.33%.Conclusion Positive contrast-enhanced CTVC improves the detection of colorectal polyps.%目的 评价结肠阳性造影CT仿真结肠镜用于诊断结直肠息肉的价值.方法 57例疑似或确诊后复查的结直肠息肉患者纳入研究,所有患者先进行结肠阳性对比剂充盈下CT仿真结肠镜检查,然后患者再行电子肠镜检查,影像科医生及内镜医生均在盲法干预下出具各自检查报告,由第三方统计人员统计CT仿真肠镜对结直肠息肉诊断的符合率.结果 以电子肠镜为金标准,则CT仿真结肠镜患者检出敏感度为95.23 %,特异度为 93.33 %;电子肠镜共检出90例息肉,仿真结肠镜共检出125例息肉.仿真结肠镜发现直径在0.3 cm以上的病灶93处,电子内镜有 90 处,对所有检出直径在0.3 cm以上病灶进行点对点比较,二者的吻合率为86.67 %,仿真结肠镜诊断的假阳性率为16.67 %,假阴性率为13.33 %.结论 阳性对比剂充盈下仿真结肠镜能提高结肠息肉的诊断效率.

  10. Virtual colonoscopy (CT colonography) in the identification of colorectal cancer. A prospective study in symptomatic patients; Impiego dell'endoscopia virtuale con Tomografia Computerizzata nell'identificazione delle neoplasie colorettali. Studio prospettivo in pazienti sintomatici

    Energy Technology Data Exchange (ETDEWEB)

    Regge, D.; Martincich, L.; Gallo, T.; Pollone, M. [Istituto per la Ricerca e la Cura del Cancro, Ordine Mauriziano, Reparto di Radiologia, Candiolo, TO (Italy); Galatola, G.; Secreto, P.; Pera, A. [Ospedale Mauriziano Umberto, Turin (Italy). Unita' Operativa di Gastroenterologia; Rivolta, A. [Istituto per la Ricerca e la Cura del Cancro, Ordine Mauriziano, Candiolo, TO (Italy). Servizio di Fisica Sanitaria

    2000-06-01

    Aim of this study was to evaluate the sensitivity of virtual colonoscopy (CT colonography) in the identification of colorectal cancer and to define the limitations and the advantages of this imaging modality, as well as indications to the examination. It was examined prospectively 62 symptomatic patients aged 36 to 82 years (28 women and 34 men). All patients underwent both conventional and virtual colonoscopy on the same day; the conventional examination allowed exploration of the entire colon. Conventional colonoscopy identified 89 lesions 3-50 mm in diameter, namely 84 benign and 5 malignant lesions. No lesions were identified in 12 patients. CT colonography identified 52 of the 89 lesions, with 57.1% diagnostic accuracy. They were 11 false positives (82.5% positive predictive value and 52.2% specificity) and 37 false negatives (24.5% negative predictive value and 58.4% sensitivity). Sensitivity was significantly higher (85.7%) for polyps {>=} 1 cm. Virtual colonoscopy is an imaging modality with good diagnostic yield, well tolerated by patients and with great potentials for further development. It was suggested that the examination be performed in symptomatic patients who cannot undergo total colonoscopy or refuse the other imaging modalities. Further studies are warranted in larger series of patients, possibly introducing it in screening programs. [Italian] Scopo di questo lavoro e' valutare la sensibilita' della colonscopia virtuale con TC nell'identificazione delle neoplasie colorettali, definendo gli attuali limiti e vantaggi della metodica e le possibili indicazioni dell'indagine. E' stato condotto uno studio prospettico su 62 pazienti sintomatici con eta' compresa fra 36 e 82 anni di cui 28 donne e 34 uomini. Tutti i pazienti sono stati sottoposti nello stesso giorno sia a colonscopia tradizionale, che in ogni caso ha consentito l'esplorazione di tutto il colon, sia a colonscopia virtuale. Con colonscopia tradizionale

  11. Digital bowel cleansing for virtual colonoscopy with probability map

    Science.gov (United States)

    Hong, Wei; Qiu, Feng

    2010-03-01

    Virtual colonoscopy (VC) is a noninvasivemethod for colonic polyp screening, by reconstructing three-dimensional models of the colon using computerized tomography (CT). Identifying the residual fluid retained inside the colon is a major challenge for 3D virtual colonoscopy using fecal tagging CT data. Digital bowel cleansing aims to segment the colon lumen from a patient abdominal image acquired using an oral contrast agent for colonic material tagging. After removing the segmented residual fluid, the clean virtual colon model can be constructed and visualized for screening. We present a novel automatic method for digital cleansing using probability map. The random walker algorithm is used to generate the probability map for air (inside the colon), soft tissue, and residual fluid instead of segment colon lumen directly. The probability map is then used to remove residual fluid from the original CT data. The proposed method was tested using VC study data at National Cancer Institute at NIH. The performance of our VC system for polyp detection has been improved by providing radiologists more detail information of the colon wall.

  12. 64排螺旋CT仿真结肠镜在结肠癌诊断中的应用%Clinical application of 64-slice spiral CT virtual colonoscopy in diagnosis of colonic carcinoma

    Institute of Scientific and Technical Information of China (English)

    张明

    2012-01-01

    目的 探讨64排螺旋CT仿真结肠镜(CT virtual colonoscopy,CTVC)及其二维三维重建在结肠占位的CT表现及临床应用.方法 回顾分析52例行64排螺旋CT双体位结肠扫描的结肠癌病例,所有患者均进行结肠充气仰卧位及俯卧位增强扫描,其中20例增加了左或右侧位三期扫描,将MSCT扫描原始数据传送至ADW4.4工作站采用CT仿真结肠镜(CTVC)、多平面重建(MPR)、表面遮盖显示(SSD)、透明重建显示(Raysum)4种方法进行结肠重建处理,对病灶的形态、大小、密度、结肠壁受损的程度、范围以及结肠外情况、淋巴结转移情况进行综合分析,做出准确判断.结果 结肠、直肠癌52例,全部病例均经过手术及纤维结肠镜检查活检病理证实.结论 MSCT仿真结肠镜可显示结肠占位病变的形态、大小及肠壁、肠周侵犯情况,多体位扫描能使病变肠管扩张充分,更好地显示病灶的细节,提高病变检出的敏感性,为临床选择合理的治疗提供有价值的依据,是诊断结肠占位的一种有效检查方法.%Objective To investigate the CT manifestations and diagnostic value of 64 - slice spiral CT virtual colonoscopy (CTVC) and its 2D/3D - reslruction in colonic neoplasms. Methods 64 - slice spiral CT scan of colon was performed in 52 patients, Spiral CT enhancing scan was performed in both the supine and prone positions after appropriately distended by introduction of air and water, and triple - phase spiral CT enhanced scan were additionally performed in 20 of 52 cases, and the data of MSCT were transferred to ADW4.4 workstation for colon reconstruction image post processing including CT virtual colonoscopy (CTVC) , multiple planar reconstruction (MPR) , shaded surface display (SSD) and Raysum display. The MSCT findings of the shape, size and density of lesions, the injury extent and range of colonic wall and extracolon, and lymph node metastasis were analyzed and estimated. Results Totally 52

  13. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Image/Video Gallery Your Radiologist Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! ... colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test ...

  14. Colonoscopy

    Science.gov (United States)

    ... that their insurance will cover. Read more about colon cancer at www. cancer. gov. 2 Colonoscopy 1 Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM. American College of Gastroenterology guidelines for ...

  15. Colonoscopy

    Science.gov (United States)

    ... be treated with rest, fluids, antibiotics, and close observation. Bleeding is reported in 0 to 6 of ... al. Complication rates of colonoscopy in an Australian teaching hospital environment. Internal Medical Journal . 2003;33:355- ...

  16. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... you today about computed tomography colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy ... might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from ...

  17. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: ... commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large ...

  18. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... you today about computed tomography colonography or, as it is more commonly known, virtual colonoscopy. Virtual colonoscopy ... might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from ...

  19. MicroPET/CT Colonoscopy in long-lived Min mouse using NM404

    Science.gov (United States)

    Christensen, Matthew B.; Halberg, Richard B.; Schutten, Melissa M.; Weichert, Jamey P.

    2009-02-01

    Colon cancer is a leading cause of death in the US, even though many cases are preventable if tumors are detected early. One technique to promote screening is Computed Tomography Colonography (CTC). NM404 is a second generation phospholipid ether analogue which has demonstrated selective uptake and prolonged retention in 43/43 types of malignant tumors but not inflammatory sites or premalignant lesions. The purpose of this experiment was to evaluate (SWR x B6 )F1.Min mice as a preclinical model to test MicroPET/CT dual modality virtual colonoscopy. Each animal was given an IV injection of 124I-NM404 (100 uCi) 24, 48 and 96 hours prior to scanning on a dedicated microPET/CT system. Forty million counts were histogrammed in 3D and reconstructed using an OSEM 2D algorithm. Immediately after PET acquisition, a 93 m volumetric CT was acquired at 80 kVp, 800 uA and 350 ms exposures. Following CT, the mouse was sacrificed. The entire intestinal tract was excised, washed, insufflated, and scanned ex vivo A total of eight tissue samples from the small intestine were harvested: 5 were benign adenomas, 2 were malignant adenocarcinomas, and 1 was a Peyer's patch (lymph tissue) . The sites of these samples were positioned on CT and PET images based on morphological cues and the distance from the anus. Only 1/8 samples showed tracer uptake. several hot spots in the microPET image were not chosen for histology. (SWR x B6)F1.Min mice develop benign and malignant tumors, making this animal model a strong candidate for future dual modality microPET/CT virtual colonography studies.

  20. Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Ayso H. de; Bipat, Shandra; Liedenbaum, Marjolein H.; Florie, Jasper; Vos, Frans M.; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Dekker, Evelien; Fockens, Paul; Mathus-Vliegen, Elizabeth M. [University of Amsterdam, Department of Gastroenterology, Academic Medical Centre, Amsterdam (Netherlands); Kraan, Roel van der; Truyen, Roel [Philips Healthcare, Department of Healthcare Informatics, Best (Netherlands); Reitsma, Johannes B.; Zwinderman, Aeilko H. [University of Amsterdam, Department of Clinical Epidemiology and Biostatistics, Amsterdam Medical Center, Amsterdam (Netherlands)

    2010-06-15

    To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window and manual 3D) compared with measurements by linear probe. All CT colonography measurements judged polyps to be larger than optical colonoscopy, with differences ranging from 0.7 to 2.3 mm. A linear probe does not reduce the measurement variability of endoscopists compared with the forceps. Measurement differences between observers on CT colonography were usually smaller than at optical colonoscopy. Polyps appeared larger when using various CT colonography techniques than when measured during optical colonoscopy. (orig.)

  1. Comparison of CT virtual endoscopy with electronic colonoscopy in 30 colonic carcinoma patients%结肠癌CT仿真内镜与电子结肠镜的对照研究(附30例报告)

    Institute of Scientific and Technical Information of China (English)

    余深平; 李子平; 袁学远; 许达生

    2001-01-01

    Abstract:Objective To evaluate the clinical application of CT virtual endoscopy (CTVE) in the diagnosis and treatment of colonic carcinoma. Methods We collected 30 patients pathologically proven to have colonic carcinomas as examined by CTVE and electronic colonoscopy (EC), correlating the CTVE and EC images respectively with surgical pathology in three aspects: tumor morphological features, degree of circumferential bowel wall involvement and longitudinal extent of tumor. Results CTVE imaging of colonic carcinomas showed morphological features: polypoid pattern (11 patients), ulcerative pattern (11), and infiltrative pattern (8); degree of circumferential bowel wall involvement: less than 1/2 (4 patients), from 1/2 to 3/4 (6), and more than 3/4 (20); and their longitudinal extent: 1.0-3.0?cm (7 patients), 31-5.0?cm (10), and 5.1-11.0?cm (13). Correlation of CTVE and EC with surgical pathology was found. Comparison of CTVE with surgical pathology showed tumor morphological features: concordant (26 patients), and disconcordant (4); degree of circumferential bowel wall involvement: concordant (25), disconcordant (5); and longitudinal extent of the tumor: concordant (23), disconcordant (7). Comparison of EC with surgical pathology showed tumor morphological features: concordant (22 patients), disconcordant (8); degree of circumferential bowel wall involvement: concordant (28), disconcordant (2); and longitudinal extent of the tumor: concordant (14), disconcordant (3), and undefined by EC (13). Conclusions The images obtained by CTVE in colonic carcinoma are similar to those obtained by EC. CTVE is an excellent alternative to EC for patients who cannot tolerate EC and for cases with incomplete EC.%目的探讨CT仿真内镜在结肠癌诊治中的临床应用.方法收集30例结肠癌的CT仿真内镜、电子结肠镜及手术病理的材料,并从肿块分型、病变环周侵犯范围及病变长度等三方面进行比较.结果结肠癌的CT

  2. Colonoscopy after CT Diagnosis of Diverticulitis to Exclude Colon Cancer: A Systematic Literature Review

    OpenAIRE

    Sai, Victor F.; Velayos, Fernando; Neuhaus, John; Westphalen, Antonio C.

    2012-01-01

    There are limited data about follow-up colonoscopy after a CT diagnosis of acute diverticulitis, and the pooled prevalence of colorectal cancer in a small number of patients is only slightly higher than the calculated prevalence of colorectal cancer in a population of comparable age.

  3. Colovesical fistula as a complication of colonic diverticulosis: diagnosis with virtual colonoscopy.

    Science.gov (United States)

    Nadır, Işılay; Ozın, Yasemin; Kiliç, Zeki Mesut Yalın; Oğuz, Dilek; Ulker, Aysel; Arda, Kemal

    2011-02-01

    A 65-year-old female patient admitted to our clinic with complaints of abdominal pain and watery diarrhea. She was diagnosed with colovesical fistula based on virtual colonoscopy findings. Since endoscopic and other radiological diagnostic tools were not able to establish a definite diagnosis, we found this case suitable for presentation.

  4. Virtual colonoscopy with multi-slice computed tomography; Virtuelle Koloskopie mit der Mehrschichtcomputertomographie. Vorlaeufige Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Rust, G.-F.; Eisele, O.; Reiser, M. [Institut fuer Klinische Radiologie, Klinikum Grosshadern, Muenchen Univ. (Germany); Hoffmann, J.N.; Kopp, R.; Fuerst, H. [Chirurgische Klinik und Poliklinik, Klinikum der Univ. Muenchen (Germany)

    2000-03-01

    Subject: Using multi-slice computed tomography (MSCT) large body areas can scanned with high spatial resolution. In this study, MSCT was employed for virtual colonoscopy in various pathologies of the colon. Results: Nine polyps and four of five colon carcinomas were detected using MSCT virtual colonoscopy. In three patients with ulcerative colitis virtual coloscopy revealed morphological alterations compatible with this disease. In two of four patients with multiple diverticula of the colon the true extent of the disorder could be assessed in virtual colonoscopy. (orig.) [German] Fragestellung: Die Mehrschichtcomputertomographie (MSCT) vermag, grosse Organbereiche mit hoher raeumlicher Aufloesung zu untersuchen. Daher koennen auch fuer die virtuelle Koloskopie eine bisher nicht erreichbare Ortsaufloesung und Detailtreue erwartet werden. Die ersten Ergebnisse mit der MSCT-Koloskopie bei unterschiedlichen pathologischen Veraenderungen des Kolons werden vorgestellt. Ergebnisse: 4 von 5 Kolonkarzinomen konnten mit der virtuellen Koloskopie dargestellt werden. Bei 3 Patienten wurden mit der virtuellen Koloskopie typische Veraenderungen der Colitis ulcerosa dargestellt, wovon ein Patient die konventionelle Koloskopie nicht tolerierte. Bei 9 Patienten mit Kolonpolypen stimmten die virtuelle und konventionelle Koloksopie vollstaendig ueberein. Bei 4 Patienten mit Divertikulose war mit der virtuellen Koloskopie nur in 2 Faellen der Befund vollstaendig zu sichern. (orig.)

  5. Virtual colonoscopy-induced perforation in a patient with Crohn's disease

    Institute of Scientific and Technical Information of China (English)

    Sunny H Wong; Vincent WS Wong; Joseph JY Sung

    2007-01-01

    We report a case of sigmoid colon perforation in a patient with Crohn's disease undergoing computed-tomographic (CT) colonography. A 70-year-old patient with Crohn's disease with terminal ileitis and sigmoid stricture underwent CT colonography after incomplete conventional colonoscopy. During the procedure, the colon was inflated by air insufflation and the patient developed abdominal pain with radiological evidence of retroperitoneal and intraperitoneal free gas. Hartmann's operation was performed. This case highlights that CT colonography is not risk-free. The risk of perforation may be higher in patients with inflammatory bowel disease.

  6. Comparison of 64-Detector CT Colonography and Conventional Colonoscopy in the Detection of Colorectal Lesions

    Directory of Open Access Journals (Sweden)

    Devir

    2016-01-01

    Full Text Available Background Colon cancer is a leading cause of morbidity and mortality in developed countries. The early detection of colorectal cancer using screening programs is important for managing early-stage colorectal cancers and polyps. Modalities that allow examination of the entire colon are conventional colonoscopy, double contrast barium enema examination and multi-detector computed tomography (MDCT colonography. Objectives To compare CT colonography and conventional colonoscopy results and to evaluate the accuracy of CT colonography for detecting colorectal lesions. Patients and Methods In a prospective study performed at Gastroenterology and Radiology Departments of Medical Faculty of Eskisehir Osmangazi University, CT colonography and colonoscopy results of 31 patients with family history of colorectal carcinoma, personal or family history of colorectal polyps, lower gastrointestinal tract bleeding, change in bowel habits, iron deficiency anemia and abdominal pain were compared. Regardless of the size, CT colonography and conventional colonoscopy findings for all the lesions were cross - tabulated and the sensitivity, specificity, and positive and negative predictive values were calculated. To assess the agreement between CT colonography and conventional colonoscopy examinations, the Kappa coefficient of agreementt was used. Statistical analysis was performed by SPSS ver 15.0. Results Regardless of the size, MDCT colonography showed 83% sensitivity and 95% specificity, with a positive predictive value of 95% and a negative predictive value of 83% for the detection of colorectal polyps and masses. MDCT colonography displayed 92% sensitivity and 95% specificity, with a positive predictive value of 92% and a negative predictive value of 95% for polyps ≥ 10 mm. For polyps between 6mm and 9 mm, MDCT colonography displayed 75% sensitivity and 100% specificity, with a positive predictive value of 100% and a negative predictive value of 90%. For polyps

  7. Two methods of Haustral fold detection from computed tomographic virtual colonoscopy images

    Science.gov (United States)

    Chowdhury, Ananda S.; Tan, Sovira; Yao, Jianhua; Linguraru, Marius G.; Summers, Ronald M.

    2009-02-01

    Virtual colonoscopy (VC) has gained popularity as a new colon diagnostic method over the last decade. VC is a new, less invasive alternative to the usually practiced optical colonoscopy for colorectal polyp and cancer screening, the second major cause of cancer related deaths in industrial nations. Haustral (colonic) folds serve as important landmarks for virtual endoscopic navigation in the existing computer-aided-diagnosis (CAD) system. In this paper, we propose and compare two different methods of haustral fold detection from volumetric computed tomographic virtual colonoscopy images. The colon lumen is segmented from the input using modified region growing and fuzzy connectedness. The first method for fold detection uses a level set that evolves on a mesh representation of the colon surface. The colon surface is obtained from the segmented colon lumen using the Marching Cubes algorithm. The second method for fold detection, based on a combination of heat diffusion and fuzzy c-means algorithm, is employed on the segmented colon volume. Folds obtained on the colon volume using this method are then transferred to the corresponding colon surface. After experimentation with different datasets, results are found to be promising. The results also demonstrate that the first method has a tendency of slight under-segmentation while the second method tends to slightly over-segment the folds.

  8. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, Division of Medicine, London (United Kingdom); Ghanouni, Alex; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Rees, Colin J. [Durham University School of Medicine, Pharmacy and Health, Durham (United Kingdom); Hewitson, Paul [University of Oxford, Health Services Research Unit, Nuffield Department of Population Health, Oxford (United Kingdom); Nickerson, Claire; Wright, Suzanne [Fulwood House, NHS Cancer Screening Programmes, Sheffield (United Kingdom)

    2017-03-15

    To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. (orig.)

  9. Can the localization of primary colonic tumors be improved by staging CT without specific bowel preparation compared to optical colonoscopy?

    Energy Technology Data Exchange (ETDEWEB)

    Feuerlein, Sebastian; Grimm, Lars J.; Davenport, Matthew S.; Haystead, Clare M.; Miller, Chad M.; Neville, Amy M. [Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710 (United States); Jaffe, Tracy A., E-mail: tracy.jaffe@duke.edu [Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710 (United States)

    2012-10-15

    Objectives: To investigate the ability of staging computed tomography (CT) without bowel preparation to accurately localize colonic tumors compared to optical colonoscopy. Methods: The local institutional review board approved this retrospective and HIPAA-compliant study. Forty-six patients with colonic adenocarcinoma, preoperative colonoscopy, and staging CT within 60 days of resection were included. Patients underwent contrast enhanced CT imaging without bowel preparation or oral contrast. The colon was divided into four segments with the operative reports used as the standard. Rectal and cecal cancers were excluded. CT scans were reviewed by 5 readers in a segmental binary fashion using a 5-point confidence scale in two sessions blinded and unblinded to the colonoscopy report. Results: At surgery 49 tumors were found in 46 patients. Readers detected 86.1%, 74.3%, and 66.9% of lesions with 92.0%, 94.1%, and 95.4% accuracy for confidence scores of ≥3, ≥4, and 5. CT interobserver agreement was good (κ = 0.82) for the unblinded and moderate (κ = 0.60) for the blinded read. Colonoscopic localization was only 78.7% accurate with 2 tumors undiscovered. Colonoscopic accuracy was low in the descending colon (57.1%) and the transverse colon (55.6%). Conclusions: Preoperative staging CT is more accurate than colonoscopy in the localization of colonic tumors.

  10. Virtual Colonoscopy

    Science.gov (United States)

    ... ray machine from taking clear images of the lining of your intestine. You may need to follow a clear liquid ... air has a small risk of perforating the lining of the large intestine. The doctor may need to treat perforation with ...

  11. CT colonography with reduced bowel preparation after incomplete colonoscopy in the elderly

    Energy Technology Data Exchange (ETDEWEB)

    Iafrate, F.; Stagnitti, A. [University of Rome, Department of Radiological Sciences, Rome (Italy); Hassan, C.; Zullo, A. [Hospital-Rome, Gastroenterology and Digestive Endoscopy Unit, Rome (Italy); Spagnuolo, A. [Univeristy of Rome, I.C.O.T, Department of Radiological Sciences, Latina (Italy); Ferrari, R.; Laghi, A.

    2008-07-15

    We prospectively assessed the feasibility and acceptance of computerized tomographic colonography (CTC) without bowel cathartic preparation in elderly patients after incomplete colonoscopy. A total of 136 patients underwent CTC without cathartic preparation. The time delay between conventional colonoscopy and CTC ranged between 3 and 20 days, depending on the clinical situation. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. CTCs were interpreted using a primary two-dimensional (2D) approach and 3D images for further characterization. Patients were interviewed before and 2 weeks after CTC to assess preparation acceptance. CTC was feasible and technically successful in all the 136 patients. Fecal tagging was judged as excellent in 113 (83%) patients and sufficient in 23 (17%). Average CT image interpretation time was 14.8 min. Six (4.4%) cases of colorectal cancer and nine (6.6%) large polyps were detected, as well as 23 (11.3%) extracolonic findings of high clinical importance. No major side effect occurred, although 25% patients reported minor side effects, especially diarrhea. Overall, 76/98 patients replied that they would be willing to repeat the test if necessary. CTC without cathartic preparation is a technically feasible and safe procedure to complete a colonic study in the elderly, prompting its use in clinical practice. (orig.)

  12. Design of a multicentre randomized trial to evaluate CT colonography versus colonoscopy or barium enema for diagnosis of colonic cancer in older symptomatic patients: The SIGGAR study

    Directory of Open Access Journals (Sweden)

    Edwards Rob

    2007-10-01

    Full Text Available Abstract Background and Aims The standard whole-colon tests used to investigate patients with symptoms of colorectal cancer are barium enema and colonoscopy. Colonoscopy is the reference test but is technically difficult, resource intensive, and associated with adverse events, especially in the elderly. Barium enema is safer but has reduced sensitivity for cancer. CT colonography ("virtual colonoscopy" is a newer alternative that may combine high sensitivity for cancer with safety and patient acceptability. The SIGGAR trial aims to determine the diagnostic efficacy, acceptability, and economic costs associated with this new technology. Methods The SIGGAR trial is a multi-centre randomised comparison of CT colonography versus standard investigation (barium enema or colonoscopy, the latter determined by individual clinician preference. Diagnostic efficacy for colorectal cancer and colonic polyps measuring 1 cm or larger will be determined, as will the physical and psychological morbidity associated with each diagnostic test, the latter via questionnaires developed from qualitative interviews. The economic costs of making or excluding a diagnosis will be determined for each diagnostic test and information from the trial and other data from the literature will be used to populate models framed to summarise the health effects and costs of alternative approaches to detection of significant colonic neoplasia in patients of different ages, prior risks and preferences. This analysis will focus particularly on the frequency, clinical relevance, costs, and psychological and physical morbidity associated with detection of extracolonic lesions by CT colonography. Results Recruitment commenced in March 2004 and at the time of writing (July 2007 5025 patients have been randomised. A lower than expected prevalence of end-points in the barium enema sub-trial has caused an increase in sample size. In addition to the study protocol, we describe our approach to

  13. Virtual CT laparoscopic imaging using intravenous cholangiography with helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Masafumi; Ishibashi, Masatoshi; Nishimura, Hiroshi; Hayabuchi, Naofumi [Kurume Univ., Fukuoka (Japan). School of Medicine

    2000-08-01

    Laparoscopic cholecystectomy is a reatively new technology that allows for minimally invasive treatment of cholelithiasis. The purpose of this paper is to demonstrate the feasibility of virtual laparoscopic imaging using helical CT cholangiography with volume rendering technique. We used the technique with ten patients with suspected gallbladder abnormalities. Our imaging sets produced high quality 3D images with excellent visualization in 70% (7/10) of all cases. Virtual laparoscopic imaging was also compared with other imaging techniques and imaging using helical scans can proved useful in preoperative imaging. Furthermore, virtual laparoscopic imaging using helical scans can in surgical planning and serve as a visual aid in discussions between radiologists, surgeons, and patients. (author)

  14. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... a virtual colonoscopy, there are several things you can do to prepare for the examination. On the ... wear a gown. After the CT scan you can return to your normal diet and go back ...

  15. Analysis of scalability of high-performance 3D image processing platform for virtual colonoscopy.

    Science.gov (United States)

    Yoshida, Hiroyuki; Wu, Yin; Cai, Wenli

    2014-03-19

    One of the key challenges in three-dimensional (3D) medical imaging is to enable the fast turn-around time, which is often required for interactive or real-time response. This inevitably requires not only high computational power but also high memory bandwidth due to the massive amount of data that need to be processed. For this purpose, we previously developed a software platform for high-performance 3D medical image processing, called HPC 3D-MIP platform, which employs increasingly available and affordable commodity computing systems such as the multicore, cluster, and cloud computing systems. To achieve scalable high-performance computing, the platform employed size-adaptive, distributable block volumes as a core data structure for efficient parallelization of a wide range of 3D-MIP algorithms, supported task scheduling for efficient load distribution and balancing, and consisted of a layered parallel software libraries that allow image processing applications to share the common functionalities. We evaluated the performance of the HPC 3D-MIP platform by applying it to computationally intensive processes in virtual colonoscopy. Experimental results showed a 12-fold performance improvement on a workstation with 12-core CPUs over the original sequential implementation of the processes, indicating the efficiency of the platform. Analysis of performance scalability based on the Amdahl's law for symmetric multicore chips showed the potential of a high performance scalability of the HPC 3D-MIP platform when a larger number of cores is available.

  16. Scalable, high-performance 3D imaging software platform: system architecture and application to virtual colonoscopy.

    Science.gov (United States)

    Yoshida, Hiroyuki; Wu, Yin; Cai, Wenli; Brett, Bevin

    2012-01-01

    One of the key challenges in three-dimensional (3D) medical imaging is to enable the fast turn-around time, which is often required for interactive or real-time response. This inevitably requires not only high computational power but also high memory bandwidth due to the massive amount of data that need to be processed. In this work, we have developed a software platform that is designed to support high-performance 3D medical image processing for a wide range of applications using increasingly available and affordable commodity computing systems: multi-core, clusters, and cloud computing systems. To achieve scalable, high-performance computing, our platform (1) employs size-adaptive, distributable block volumes as a core data structure for efficient parallelization of a wide range of 3D image processing algorithms; (2) supports task scheduling for efficient load distribution and balancing; and (3) consists of a layered parallel software libraries that allow a wide range of medical applications to share the same functionalities. We evaluated the performance of our platform by applying it to an electronic cleansing system in virtual colonoscopy, with initial experimental results showing a 10 times performance improvement on an 8-core workstation over the original sequential implementation of the system.

  17. Diagnostic value of CT-colonography as compared to colonoscopy in an asymptomatic screening population: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Amsterdam, Department of Radiology, G1-223.1, Amsterdam (Netherlands); Gelder, Rogier E. van; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Graser, Anno [University of Munich, Department of Clinical Radiology, Klinikum Grosshadern, Munich (Germany)

    2011-08-15

    Previous meta-analyses on CT-colonography included both average and high risk individuals, which may overestimate the diagnostic value in screening. A meta-analysis was performed to obtain the value of CT-colonography for screening. A search was performed using PubMed, Embase and Cochrane. Article selection and critical appraisal was done by two reviewers. Inclusion criteria: prospective, randomized trials or cohort studies comparing CT-colonography with colonoscopy ({>=}50 participants), {>=}95% average risk participants {>=}50 years. Study characteristics and 2 x 2 contingency Tables were recorded. Sensitivity and specificity estimates were calculated per patient and per polyp ({>=}6 mm, {>=}10 mm), using univariate and bivariate analyses. Five of 1,021 studies identified were included, including 4,086 participants (<1% high risk). I{sup 2}-values showed substantial heterogeneity, especially for 6-9 mm polyps and adenomas: 68.1% vs. 78.6% (sensitivity per patient). Estimated sensitivities for patients with polyps or adenomas {>=} 6 mm were 75.9% and 82.9%, corresponding specificities 94.6% and 91.4%. Estimated sensitivities for patients with polyps or adenomas {>=} 10 mm were 83.3% and 87.9%, corresponding specificities 98.7% and 97.6%. Estimated sensitivities per polyp for advanced adenomas {>=} 6 mm and {>=} 10 mm were 83.9% and 83.8%. Compared to colonoscopy, CT-colonography has a high sensitivity for adenomas {>=} 10 mm. For (advanced) adenomas {>=} 6 mm sensitivity is somewhat lower. (orig.)

  18. Virtual colonoscopy: effect of computer-assisted detection (CAD) on radiographer performance

    Energy Technology Data Exchange (ETDEWEB)

    Burling, D. [St Mark' s Hospital, Harrow, Middlesex (United Kingdom)], E-mail: burlingdavid@yahoo.co.uk; Moore, A.; Marshall, M.; Weldon, J.; Gillen, C.; Baldwin, R.; Smith, K.; Pickhardt, P.; Honeyfield, L.; Taylor, S. [St Mark' s Hospital, Harrow, Middlesex (United Kingdom)

    2008-05-15

    Aim: To investigate the effect of a virtual colonoscopy (VC) computed-assisted detection (CAD) system on polyp detection by trained radiographers. Materials and methods: Four radiographers trained in VC interpretation and utilization of CAD systems read a total of 62 endoscopically validated VC examinations containing 150 polyps (size range 5-50 mm) in four sessions, recording any polyps found and the examination interpretation time, first without and then with the addition of CAD as a 'second reader'. After a temporal separation of 6 weeks to reduce recall bias, VC examinations were re-read using 'concurrent reader' CAD. Interpretation times, polyp detection, and number of false-positives were compared between the different reader paradigms using paired t and paired exact tests. Results: Overall, use of 'second reader' CAD significantly improved polyp detection by 12% (p < 0.001, CI 6%,17%)) from 48 to 60%. There was no significant improvement using CAD as a concurrent reader (p = 0.20; difference of 7%, CI -3%, 16%) and no significant overall difference in recorded false-positives with second reader or concurrent CAD paradigms compared with unassisted reading (p = 0.25 and 0.65, respectively). The mean interpretation time was 21.7 min for unassisted reading, 29.6 (p < 0.001) min for second reader and 19.1 min (p = 0.12) for concurrent reading paradigms. Conclusion: CAD, when used as a second reader, can significantly improve radiographer reading performance with only a moderate increase in interpretation times.

  19. Effect of visualization display colour on polyp conspicuity at virtual colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Burling, D. [Intestinal Imaging Centre, St Mark' s Hospital, Harrow, Middlesex (United Kingdom)], E-mail: burlingdavid@yahoo.co.uk; Moore, A.; Gupta, A.; East, J.; Tam, E.; Pickhardt, P.J.; Marshall, M.; Taylor, S.A. [Intestinal Imaging Centre, St Mark' s Hospital, Harrow, Middlesex (United Kingdom)

    2008-09-15

    Aim: To investigate the effect of different colour three-dimensional (3D) displays on polyp detection at virtual colonoscopy (VC). Methods: Five VC trained observers were shown 'brief flashes' (lasting 0.2 s) of 125 3D endoluminal image snap-shots, repeated for each of six display colours (750 images total). One hundred images contained a single polyp (diameter range 5-42 mm) and 25 contained no polyp ('normal'). Images were reviewed in random order over five reading sessions, readers recording either normality or presence and location of a polyp. Multilevel logistic regression was used to examine any influence of colour on polyp detection stratified according to polyp size (medium 5-9 mm/large {>=}10 mm). The kappa statistic was used to assess effect of colour on observer agreement. Results: Individual reader polyp detection rates ranged between 75-94%. Compared to the default pink 'soft tissue' display, the odds of polyp detection were 0.65 (CI 0.41,1.01) for green, 0.82 (0.53,1.30) for blue, 1 (0.63,1.59) for red, 1.12 (0.7,1.79) for monochrome, and 1.15 for yellow (0.72,1.84). Overall, there was no significant difference between the displays (p = 0.11). Including normal cases, there was no overall difference in correct case classification between the six colours (p = 0.44). The odds of detecting large versus medium polyps was significantly greater for 3/5 observers; odds ratio (OR) 2.84-10.1, although unaffected by display colour (p = 0.3). Conclusion: The background colour display generally has a minimal effect on polyp detection at VC, although green should be avoided.

  20. Hallazgos extracolónicos en estudios de colonoscopía virtual Extracolonic findings in virtual colonoscopy studies

    Directory of Open Access Journals (Sweden)

    Andrés J. Quaranta

    2011-06-01

    poner a los HEC en el contexto general del paciente.Purpose. Analize the presence and type of extra-colonic findings (ECF in virtual colonoscopy (VC exams and evaluate the behavior after the diagnosis. Materials and Methods. 100 VC exams were retrospectively analyzed in search of ECF regardless of the outcome of the VC. The study population consisted of 62 women and 38 men with an average age of 63. The purpose of the exam included asymptomatic patients for screening as well as patients with apparent diagnosis of neoplasm pathology and cases which came with incomplete optical colonoscopies. The studies were carried out with a Philips Brilliance of 64 detector rows with specific protocol for VC. All patients received bowel cleansing and barium-based fecal tagging. The ECF were categorized as being of low, moderate or high importance. The findings of low or no importance are those benign alterations or those alterations that are unlikely to require further examination. Moderate importance ECF are defined as alterations that do not require immediate treatment but that will probably need investigation or treatment later. High importance ECF involve significant alterations that require surgical treatment, medical intervention or new tests in short term. Results. Out of 100 patients, 66 presented ECF. In total there were 122 ECF that were distributed as follows, 61% of low importance, 26% of moderate importance and 13% of high importance. Conclusions. Extracolonic evaluation needs to be handled with extreme care and judgement by the physician who interprets the study and also by the one who receives it. It is crucial to place ECF in the general context of the patient.

  1. Diagnostic accuracy and tolerability of contrast enhanced CT colonoscopy in symptomatic patients with increased risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ozsunar, Yelda [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey)], E-mail: yozsunar@adu.edu.tr; Coskun, Guelten [Izmir Ataturk Egitim ve Arastirma Hastanesi, Izmir (Turkey); Delibas, Naciye; Uz, Burcin [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey); Yuekselen, Vahit [Department of Gastroenterology, School of Medicine, Adnan Menderes University, Aydin (Turkey)

    2009-09-15

    Objective: We compared the accuracy and tolerability of intravenous contrast enhanced spiral computed tomography colonography (CTC) and optical colonoscopy (OC) for the detection of colorectal neoplasia in symptomatic patients for colorectal neoplasia. Methods: A prospective study was performed in 48 patients with symptomatic patients with increased risk for colorectal cancer. Spiral CTC was performed in supine and prone positions after colonic cleansing. The axial, 2D MPR and virtual endoluminal views were analyzed. Results of spiral CTC were compared with OC which was done within 15 days. The psychometric tolerance test was asked to be performed for both CTC and colonoscopy after the procedure. Results: Ten lesions in 9 of 48 patients were found in CTC and confirmed with OC. Two masses and eight polyps, consisted of 1 tubulovillous, 1 tubular, 2 villous adenoma, 4 adenomatous polyp, 4 adenocarcinoma, were identified. Lesion prevalence was 21%. Sensitivity, specificity, accuracy, positive and negative predictive values were found 100%, 87%, 89%, 67% and 100%, respectively. Psychometric tolerance test showed that CTC significantly more comfortable comparing with OC (p = 0.00). CTC was the preferred method in 37% while OC was preferred in 6% of patients. In both techniques, the most unpleasant part was bowel cleansing. Conclusion: Contrast enhanced CTC is a highly accurate method in detecting colorectal lesions. Since the technique was found to be more comfortable and less time consuming compare to OE, it may be preferable in management of symptomatic patients with increased risk for colorectal cancer.

  2. Usefulness of CT virtual endoscopy in imaging a large esophagorespiratory fistula

    Energy Technology Data Exchange (ETDEWEB)

    Sonomura, Tetsuo; Kishi, Kazushi; Ishii, Seigo; Kawai, Nobuyuki; Masuda, Mitsunori; Terada, Masaki; Nakamine, Hirokazu; Sato, Morio

    2000-04-01

    A 73-year-old woman with a large esophagorespiratory fistula underwent bronchoscopy and computed tomographic (CT) virtual endoscopy before stenting. Noninvasive CT virtual endoscopy showed the large fistula, and the CT findings agreed with the bronchoscopic findings.

  3. Comparison of a 4-Day versus 2-Day Low Fiber Diet Regimen in Barium Tagging CT Colonography in Incomplete Colonoscopy Patients

    Directory of Open Access Journals (Sweden)

    Kaan Meric

    2015-01-01

    Full Text Available Our aim was to compare the amount of residual feces, residual fluid, the tagging quality, and patient compliance using 4-day versus 2-day low fiber diet regimen in barium tagging CT colonography in incomplete colonoscopy patients. Methods. A total of 101 patients who underwent CT colonography were assigned to 2-day diet group (n=56 and 4-day diet group (n=45. Fecal tagging was achieved with barium sulphate while bisacodyl and sennoside B were used for bowel preparation. Residual solid stool was divided into two groups measuring 0.05. The prevalence of moderate discomfort was significantly higher in 4-day group (P<0.001. Conclusion. Our study shows that 2-day limited bowel preparation regimen for fecal tag CT colonography is a safe and reasonable technique to evaluate the entire colon, particularly in incomplete conventional colonoscopy patients.

  4. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial

    Directory of Open Access Journals (Sweden)

    Gareen IF

    2015-07-01

    Full Text Available Ilana F Gareen,1,2 Bettina Siewert,3 David J Vanness,4 Benjamin Herman,2 CD Johnson,5 Constantine Gatsonis2,6 1Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA; 2Center for Statistical Sciences, Brown University School of Public Health, Providence, RI, USA; 3Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA; 4Population Health Sciences, University of Wisconsin, Madison, WI, USA; 5Mayo Clinic, Scottsdale, AZ, USA; 6Department of Biostatistics, Brown University School of Public Health, Providence, RI, USA Background: Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC every 5 years. Bowel preparation (BP is currently required for both screening modalities.Purpose: To compare ACRIN 6664: the National CT Colonography Trial (NCTCT participant experiences with CTC and optical colonoscopy (OC, procedure preference, and willingness to return for each procedure.Materials and methods: Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals.Results: A total of 2,310 of 2,600 patients (89% returned their questionnaires. Of patients reporting a preference, 1,058 (46.6% preferred CTC, 569 (25.0% preferred OC, and 626 (27.6% reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9% and OC (5.0% (P<0.001. About 79.3% were willing to be screened again with CTC in 5 years, and 96.6% with OC in 10 years. Discomfort and embarrassment worse than expected with OC were associated

  5. Colonoscopy tutorial software made with a cadaver's sectioned images.

    Science.gov (United States)

    Chung, Beom Sun; Chung, Min Suk; Park, Hyung Seon; Shin, Byeong-Seok; Kwon, Koojoo

    2016-11-01

    Novice doctors may watch tutorial videos in training for actual or computed tomographic (CT) colonoscopy. The conventional learning videos can be complemented by virtual colonoscopy software made with a cadaver's sectioned images (SIs). The objective of this study was to assist colonoscopy trainees with the new interactive software. Submucosal segmentation on the SIs was carried out through the whole length of the large intestine. With the SIs and segmented images, a three dimensional model was reconstructed. Six-hundred seventy-one proximal colonoscopic views (conventional views) and corresponding distal colonoscopic views (simulating the retroflexion of a colonoscope) were produced. Not only navigation views showing the current location of the colonoscope tip and its course, but also, supplementary description views were elaborated. The four corresponding views were put into convenient browsing software to be downloaded free from the homepage (anatomy.co.kr). The SI colonoscopy software with the realistic images and supportive tools was available to anybody. Users could readily notice the position and direction of the virtual colonoscope tip and recognize meaningful structures in colonoscopic views. The software is expected to be an auxiliary learning tool to improve technique and related knowledge in actual and CT colonoscopies. Hopefully, the software will be updated using raw images from the Visible Korean project. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Colonography by CT,MRI and PET/CT combined with conventional colonoscopy in colorectal cancer screening and staging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Colorectal cancer(CRC)remains a leading cancer killer worldwide.But the disease is both curable and preventable at an early stage.Regular CRC cancer screening has been shown to reduce the risk of dying from CRC.However,the importance of large-scale screening is only now starting to be appreciated.This article reviews a variety of imaging procedures available for detecting ulcerative colitis(UC)and Crohn's disease (CD),polyps and CRC in their early stage and also presents details on various screening options.Detecting,staging and re-staging of patients with CRC also require multimodality,multistep imaging approaches.Staging and re-staging with conventional colonoscopy(CC),computer tomography colonography(CTC),magnetic resonance colonography(MRC)and positron emission tomography/computer tomography colonography(PET/CTC)are of paramount importance in determining the most appropriate therapeutic method and in predicting the risk of tumor recurrence and overall prognosis.The advantages and limitations of these modalities are also discussed.

  7. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial.

    Science.gov (United States)

    Gareen, Ilana F; Siewert, Bettina; Vanness, David J; Herman, Benjamin; Johnson, C D; Gatsonis, Constantine

    2015-01-01

    Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC) every 5 years. Bowel preparation (BP) is currently required for both screening modalities. To compare ACRIN 6664: the National CT Colonography Trial (NCTCT) participant experiences with CTC and optical colonoscopy (OC), procedure preference, and willingness to return for each procedure. Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals. A total of 2,310 of 2,600 patients (89%) returned their questionnaires. Of patients reporting a preference, 1,058 (46.6%) preferred CTC, 569 (25.0%) preferred OC, and 626 (27.6%) reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9%) and OC (5.0%) (Pembarrassment worse than expected with OC were associated with increased intention to adhere with CTC in the future. Conversely, embarrassment experienced during CTC and discomfort worse than expected on CTC were associated with increased intention to adhere with OC in the future. While a larger proportion of participants indicated that they preferred CTC to OC, willingness to undergo repeat CTC compared to OC was limited by unanticipated exam discomfort and embarrassment and CTC's shorter screening interval.

  8. CT colonography versus colonoscopy in the follow-up of patients after diverticulitis - A prospective, comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Hjern, F. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden)]. E-mail: fredrik.hjern@ds.se; Jonas, E. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Holmstroem, B. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Josephson, T. [Division of Radiology, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm (Sweden); Mellgren, A. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden); Division of Colon and Rectal Surgery, University of Minnesota, Minneapolis, Minnesota (United States); Johansson, C. [Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institut, Stockholm (Sweden)

    2007-07-15

    Aim: To assess whether computed tomography colonography (CTC) is a viable alternative to colonoscopy or double contrast barium enema in the follow-up of patients after diverticulitis. Material and methods: Fifty patients underwent CTC followed immediately by colonoscopy. Results were blinded to the examiners. Findings of diverticular disease and patient acceptance were evaluated. Results: Bowel preparation and distension were good in the majority of CTC and colonoscopy examinations. Diverticular disease was found in 96% of patients at CTC and in 90% at colonoscopy. The rate of agreement between CTC and colonoscopy for diverticular findings in the sigmoid colon was good ({kappa} = 0.64). No complications were seen. Patients found colonoscopy more uncomfortable (p < 0.03), more painful (p < 0.001), and more difficult (p < 0.01) than CTC. Of the patients favouring one examination, 74% preferred CTC. Conclusion: CTC appears to have a better diagnostic potential for imaging of diverticular disease-specific findings, when compared with colonoscopy. Also, CTC was less uncomfortable and was preferred by a majority of patients. CTC seems to be a reasonable alternative in follow-up of patients with symptomatic diverticular disease.

  9. Novel method for digital subtraction of tagged stool in virtual colonoscopy

    Science.gov (United States)

    Guendel, Lutz; Suehling, Michael; Eckert, Helmut

    2008-03-01

    Colon cancer is one of the most frequent causes of death. CT colonography is a novel method for the detection of polyps and early cancer. The general principle of CT colonography includes a cathartic bowel preparation. The resulting discomfort for patients leads to limited patient acceptance and therefore to limited cancer detection rates. Reduced bowel preparation, techniques for stool tagging, and electronic cleansing, however, improve the acceptance rates. Hereby, the high density of oral contrast material highlights residual stool and can be digitally removed. Known subtraction methods cause artifacts: additional 3D objects are introduced and small bowel folds are perforated. We propose a new algorithm that is based on the 2 nd derivative of the image data using the Hessian matrix and the following principal axis transform to detect tiny folds which shall not be subtracted together with tagged stool found by a thresholding method. Since the stool is usually not homogenously tagged with contrast media a detection algorithm for island-like structures is incorporated. The interfaces of air-stool level and colon wall are detected by a 3-dimensional difference of Gaussian module. A 3-dimensional filter smoothes the transitions between removed stool and colon tissue. We evaluated the efficacy of the new algorithm with 10 patient data sets. The results showed no introduced artificial objects and no perforated folds. The artifacts at the air-stool and colon tissue-stool transitions are considerably reduced compared to those known from the literature.

  10. Enhanced CT and CT virtual endoscopy in diagnosis of heterotopic pancreas

    Institute of Scientific and Technical Information of China (English)

    Dan Wang; Xiao-Er Wei; Lei Yan; Yu-Zhen Zhang; Wen-Bin Li

    2011-01-01

    AIM: To improve the diagnosis of heterotopic pancreas by the use of contrast-enhanced 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. Non-enhanced CT and enhanced CT scanning were performed, and the resulting images were reviewed and analyzed using.three-dimensional post-processing 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.

  11. Virtual anthropology and forensic identification using multidetector CT.

    Science.gov (United States)

    Dedouit, F; Savall, F; Mokrane, F-Z; Rousseau, H; Crubézy, E; Rougé, D; Telmon, N

    2014-04-01

    Virtual anthropology is made possible by modern cross-sectional imaging. Multislice CT (MSCT) can be used for comparative bone and dental identification, reconstructive identification and lesion identification. Comparative identification, the comparison of ante- and post-mortem imaging data, can be performed on both teeth and bones. Reconstructive identification, a considerable challenge for the radiologist, identifies the deceased by determining sex, geographical origin, stature and age at death. Lesion identification combines virtual autopsy and virtual anthropology. MSCT can be useful in palaeopathology, seeking arthropathy, infection, oral pathology, trauma, tumours, haematological disorders, stress indicators or occupational stress in bones and teeth. We examine some of the possibilities offered by this new radiological subspeciality that adds a new dimension to the work of the forensic radiologist. A multidisciplinary approach is crucial and involves communication and data exchange between radiologists, forensic pathologists, anthropologists and radiographers.

  12. Incidental colonic focal FDG uptake on PET/CT: can the maximum standardized uptake value (SUV{sub max}) guide us in the timing of colonoscopy?

    Energy Technology Data Exchange (ETDEWEB)

    Hoeij, F.B. van; Stadhouders, P.H.G.M.; Weusten, B.L.A.M. [St Antonius Ziekenhuis, Department of Gastroenterology, Nieuwegein (Netherlands); Keijsers, R.G.M. [St Antonius Ziekenhuis, Department of Nuclear Medicine, Nieuwegein (Netherlands); Loffeld, B.C.A.J. [Zuwe Hofpoort Ziekenhuis, Department of Internal Medicine, Woerden (Netherlands); Dun, G. [Ziekenhuis Rivierenland, Department of Internal Medicine, Tiel (Netherlands)

    2015-01-15

    In patients undergoing {sup 18}F-FDG PET/CT, incidental colonic focal lesions can be indicative of inflammatory, premalignant or malignant lesions. The maximum standardized uptake value (SUV{sub max}) of these lesions, representing the FDG uptake intensity, might be helpful in differentiating malignant from benign lesions, and thereby be helpful in determining the urgency of colonoscopy. The aim of our study was to assess the incidence and underlying pathology of incidental PET-positive colonic lesions in a large cohort of patients, and to determine the usefulness of the SUV{sub max} in differentiating benign from malignant pathology. The electronic records of all patients who underwent FDG PET/CT from January 2010 to March 2013 in our hospital were retrospectively reviewed. The main indications for PET/CT were: characterization of an indeterminate mass on radiological imaging, suspicion or staging of malignancy, and suspicion of inflammation. In patients with incidental focal FDG uptake in the large bowel, data regarding subsequent colonoscopy were retrieved, if performed within 120 days. The final diagnosis was defined using colonoscopy findings, combined with additional histopathological assessment of the lesion, if applicable. Of 7,318 patients analysed, 359 (5 %) had 404 foci of unexpected colonic FDG uptake. In 242 of these 404 lesions (60 %), colonoscopy follow-up data were available. Final diagnoses were: adenocarcinoma in 25 (10 %), adenoma in 90 (37 %), and benign in 127 (53 %). The median [IQR] SUV{sub max} was significantly higher in adenocarcinoma (16.6 [12 - 20.8]) than in benign lesions (8.2 [5.9 - 10.1]; p < 0.0001), non-advanced adenoma (8.3 [6.1 - 10.5]; p < 0.0001) and advanced adenoma (9.7 [7.2 - 12.6]; p < 0.001). The receiver operating characteristic curve of SUV{sub max} for malignant versus nonmalignant lesions had an area under the curve of 0.868 (SD ± 0.038), the optimal cut-off value being 11.4 (sensitivity 80 %, specificity 82

  13. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Therapy November 8 is the International Day of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your ... Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! Hi, I’m Dr. Elliot ...

  14. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... to your normal diet and go back to work the same day in most cases. Perhaps you might have some concerns about CT scanning. However, it’s important to consider the likelihood of benefit from this exam to your health. While virtual colonoscopy does use radiation, the benefit ...

  15. Virtual non-contrast CT using dual energy spectral CT: Feasibility of coronary artery calcium scoring

    Energy Technology Data Exchange (ETDEWEB)

    Song, In Young; Yi, Jeong Geun; Park, Jeong Hee [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of); Lee, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs). The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

  16. CT colonography with limited bowel preparation: prospective assessment of patient experience and preference in comparison to optical colonoscopy with cathartic bowel preparation

    Energy Technology Data Exchange (ETDEWEB)

    Jensch, Sebastiaan [University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Bipat, Shandra; Vries, Ayso H. de; Heutinck, Anneke; Stoker, Jaap [University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Peringa, Jan; Montauban van Swijndregt, Alexander D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Dekker, Evelien [University of Amsterdam, Department of Gastroenterology and Hepatology, Amsterdam (Netherlands); Baak, Lubbertus C. [Onze Lieve Vrouwe Gasthuis, Department of Gastroenterology, Amsterdam (Netherlands)

    2010-01-15

    The purpose of this study was to prospectively compare participant experience and preference of limited preparation computed tomography colonography (CTC) with full-preparation colonoscopy in a consecutive series of patients at increased risk of colorectal cancer. CTC preparation comprised 180 ml diatrizoate meglumine, 80 ml barium and 30 mg bisacodyl. For the colonoscopy preparation 4 l of polyethylene glycol solution was used. Participants' experience and preference were compared using the Wilcoxon signed rank test and the chi-squared test, respectively. Associations between preference and experience parameters for the 173 participants were determined by logistic regression. Diarrhoea occurred in 94% of participants during CTC preparation. This side effect was perceived as severely or extremely burdensome by 29%. Nonetheless, the total burden was significantly lower for the CTC preparation than for colonoscopy (9% rated the CTC preparation as severely or extremely burdensome compared with 59% for colonoscopy; p<0.001). Participants experienced significantly more pain, discomfort and total burden with the colonoscopy procedure than with CTC (p<0.001). After 5 weeks, 69% preferred CTC, 8% were indifferent and 23% preferred colonoscopy (p<0.001). A burdensome colonoscopy preparation and pain at colonoscopy were associated with CTC preference (p<0.04). In conclusion, participants' experience and preference were rated in favour of CTC with limited bowel preparation compared with full-preparation colonoscopy. (orig.)

  17. Small cell carcinoma of the urinary bladder: Virtual CT cystoscopic findings

    Directory of Open Access Journals (Sweden)

    Tsili A

    2009-01-01

    Full Text Available A 74-year-old man underwent multidetector CT virtual cystoscopy due to macroscopic hematuria. A large, irregularly-surfaced, solid bladder mass was detected, infiltrating the perivesical fat, the seminal vesicles and the prostate. CT examination of the chest and abdomen showed no distant metastases. Radical cystectomy was performed and pathology reported pure small cell carcinoma of the urinary bladder.

  18. CT colonography: an update

    Energy Technology Data Exchange (ETDEWEB)

    Aschoff, Andrik J.; Ernst, Andrea S.; Brambs, Hans-Juergen; Juchems, Markus S. [University Hospitals of Ulm, Diagnostic and Interventional Radiology, Ulm (Germany)

    2008-03-15

    Computed tomographic (CT) colonography (CTC) - also known as ''virtual colonoscopy'' - was first described more than a decade ago. As advancements in scanner technology and three-dimensional (3D) postprocessing helped develop this method to mature into a potential option in screening for colorectal cancer, the fundamentals of the examination remained the same. It is a minimally invasive, CT-based procedure that simulates conventional colonoscopy using 2D and 3D computerized reconstructions. The primary aim of CTC is the detection of colorectal polyps and carcinomas. However, studies reveal a wide performance variety in regard to polyp detection, especially for smaller polyps. This article reviews the available literature, discusses established indications as well as open issues and highlights potential future developments of CTC. (orig.)

  19. CT virtual reality in the preoperative workup of malunited distal radius fractures: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, Michael; Gruber, Hannes; Jaschke, Werner R. [Innsbruck University Hospital, Department of Radiology I, Innsbruck (Austria); Gabl, Markus [Innsbruck University Hospital, Department of Trauma Surgery, Innsbruck (Austria); Mallouhi, Ammar [Innsbruck University Hospital, Department of Radiology II, Innsbruck (Austria)

    2005-04-01

    Our objective was to evaluate the usefulness of CT virtual preoperative planning in the surgical repositioning of malunited distal radius fracture. Eleven patients with malunited distal radius fracture underwent multislice CT of both wrists. A preoperative workup was performed in a virtual reality environment created from the CT data sets. Virtual planning comprised three main procedures, carrying out the virtual osteotomy of the radius, prediction of the final position of the distal radius after osteotomy and computer-assisted manufacturing of a repositioning device, which was later placed at the surgical osteotomy site to reposition objectively the distal radius fragment before fixation with the osteosynthesis. All patients tolerated the surgical procedure well. During surgery, the orthopedic surgeons were not required in any of the cases to alter the position of the distal radius that was determined by the repositioning device. At postoperative follow-up, the anatomic relationship of the distal radius was restored (radial inclination, 21.4 ; volar tilt, 10.3 ; ulnar variance, 0.5 mm). Clinically, a significant improvement of pronation (P=0.012), supination (P=0.01), flexion (P=0.001) and extension (P=0.006) was achieved. Pain decreased from 54 to 7 points. CT virtual reality is a valuable adjunct for the preoperative workup and surgical reposition of malunited distal radius fractures. (orig.)

  20. Spiral CT colonography in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Tarjan, Zsolt E-mail: tarjan@radi.sote.hu; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K

    2000-09-01

    Objective: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. Methods and material: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. Results: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. Conclusion: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease.

  1. Distensión colónica con bomba de CO2: Impacto en el disconfort del paciente en los estudios de colonoscopía virtual Colonic distention with CO2 insufflation: Impact on the patient's discomfort in virtual colonoscopy studies

    Directory of Open Access Journals (Sweden)

    Patricia Carrascosa

    2011-12-01

    Full Text Available Objetivos. Analizar el rol de la distensión colónica con CO2 y su influencia en el disconfort del paciente y en el tiempo de duración de la colonoscopía virtual en nuestra práctica diaria. Materiales y Métodos. Se estudiaron 200 pacientes, 50 insuflados con aire ambiental y 150 con CO2. Los estudios se realizaron con un equipo multidetector de 64 filas con cortes de 2 mm de espesor, 120 kV y 50 mAs. En todos los pacientes se efectuó una adquisición en decúbito supino y otra en prono. Se calculó el tiempo total del procedimiento en cada grupo y se utilizó una prueba "t de Student" para calcular las diferencias. Los pacientes completaron un cuestionario en referencia al grado de disconfort percibido. Se utilizó una escala de 0 a 3: 0- sin disconfort, 1- disconfort leve, 2- moderado y 3- severo. Se utilizó un test de proporciones para calcular las diferencias del grado de disconfort entre ambos grupos. Resultados. El tiempo total de los procedimientos fue de 30,5 minutos para los realizados con CO2 y 35,4 minutos para los efectuados con aire ambiental, con una diferencia de -4,9 min (p=0,0003. En la valoración del disconfort, en el grupo con insuflado con aire ambiental, el 44% de los pacientes manifestó un grado de disconfort moderado, mientras que en el grupo con CO2 el 76% manifestó ausencia de disconfort. Conclusiones. La colonoscopía virtual realizada con insuflación de CO2 permitió disminuir en forma parcial el tiempo total del examen y, de modo significativo, el disconfort durante y después del examen.Objectives. To analyze the role of colonic distention with CO2 and its influence on patients' discomfort and the duration of the virtual colonoscopy procedure in our daily practice. Materials and Methods. Two hundred patients were evaluated, 50 were insufflated using room air and 150 with CO2. The studies were performed with a 64-row CT scanner using 2-mm slice thickness, 120 kV and 50 mAs. In all patients, scans were

  2. Interlaboratory Comparison of a physical and a virtual assembly measured by CT

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo

    2017-01-01

    In a comparison including 20 laboratories, a physical as well as a virtual assembly provided as two data sets were used to investigate measuring and post-processing approaches in Computed Tomography, CT. Different procedures were used in the comparison including one simulating in-line measurement...

  3. WE-AB-BRA-12: Virtual Endoscope Tracking for Endoscopy-CT Image Registration

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, W; Rao, A; Wendt, R; Court, L [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, TX (United States); Yang, J; Beadle, B [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: The use of endoscopy in radiotherapy will remain limited until we can register endoscopic video to CT using standard clinical equipment. In this phantom study we tested a registration method using virtual endoscopy to measure CT-space positions from endoscopic video. Methods: Our phantom is a contorted clay cylinder with 2-mm-diameter markers in the luminal surface. These markers are visible on both CT and endoscopic video. Virtual endoscope images were rendered from a polygonal mesh created by segmenting the phantom’s luminal surface on CT. We tested registration accuracy by tracking the endoscope’s 6-degree-of-freedom coordinates frame-to-frame in a video recorded as it moved through the phantom, and using these coordinates to measure CT-space positions of markers visible in the final frame. To track the endoscope we used the Nelder-Mead method to search for coordinates that render the virtual frame most similar to the next recorded frame. We measured the endoscope’s initial-frame coordinates using a set of visible markers, and for image similarity we used a combination of mutual information and gradient alignment. CT-space marker positions were measured by projecting their final-frame pixel addresses through the virtual endoscope to intersect with the mesh. Registration error was quantified as the distance between this intersection and the marker’s manually-selected CT-space position. Results: Tracking succeeded for 6 of 8 videos, for which the mean registration error was 4.8±3.5mm (24 measurements total). The mean error in the axial direction (3.1±3.3mm) was larger than in the sagittal or coronal directions (2.0±2.3mm, 1.7±1.6mm). In the other 2 videos, the virtual endoscope got stuck in a false minimum. Conclusion: Our method can successfully track the position and orientation of an endoscope, and it provides accurate spatial mapping from endoscopic video to CT. This method will serve as a foundation for an endoscopy-CT registration

  4. [CT and MR virtual colonscopy: indications, limits and comparison with conventional colonscopy].

    Science.gov (United States)

    Bertini, L; Campagnano, S; Lanciotti, S; Fiorello, S; Fabiani, B; Graziani, M G; Gualdi, G F

    2006-01-01

    Virtual endoscopy is a new method for studying the colon; it consists in acquisition of CT and MR images and to elaborate them with a workstation, to create endoluminal vision as like as traditional colonscopy, permitting the complete exploration of colonic lumen, also with stenotic tumors. The analysis of the differences between CT and MR colography shows like these two techniques present both advantages and disadvantages, such as the impossibility to perform MR in patients with pace-maker or in claustrophobic patients and the impossibility to perform CT with iodated agents in patients with renal failure or with a story of adverse reactions. The increased use of these techniques is due to the high sensitivity of last-generation CT and MR machine, to the increased spatial resolution, to specific softwares for digital cleaning of colon, to the introduction of high-end workstations and to the possibility of computed assisted diagnosis (CAD). So, it is desiderable that the increasing spread of multidetector CT devices and the future technical innovations, should have the effect to increase culture and experience in various diagnostic centers about CT-colography, making possible the spreading of virtual endoscopy as a screening tool.

  5. Multi-detector CT-colonography in inflammatory bowel disease: Prospective analysis of CT-findings to high-resolution video colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Kjel [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)]. E-mail: kjel_andersen@web.de; Vogt, Christoph [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Blondin, Dirk [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Beck, Andreas [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Heinen, Wolfram [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Aurich, Volker [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Haeussinger, Dieter [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Moedder, Ulrich [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Cohnen, Mathias [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)

    2006-04-15

    Aim: Prospective analysis of multi-detector CT-colonography (MDCTC) in patients with inflammatory bowel disease (IBD) compared to high-resolution video-endoscopy (HRVC). Materials and methods: Twenty-one patients (mean age 49.6 years) with Crohn's disease or ulcerative colitis underwent MDCTC (Somatom Volume Zoom, Siemens, Erlangen; 1 mm collimation, Pitch 8, 100 mAs, 120 kVp). HRVC was performed within 2 h after MDCTC. MDCTC was analyzed by two blinded readers. MDCTC-findings including bowel wall alterations and extraintestinal changes were compared to results of HRVC. Results: Over-all-sensitivity was 100% for endoluminal lesions with correct diagnosis of two cancers. Acute and chronic IBD were correctly identified by MDCTC in 63.6%, and 100%, respectively, with a specificity of 75%, and 100%. Sensitivity, specificity, positive and negative predictive values of MDCTC for diagnosis of acute and chronic disease were best for chronic disease. Sensitivity was worst for acute ulcerative colitis and specificity was worst for acute Crohn's disease. Haustral loss was seen only in ulcerative colitis. Pseudopolyps and fistulae were findings exclusive to Crohn's disease. Particularly extraintestinal findings as increased vascularization and local lymphadenopathy correlated well with endoscopic definition of acute disease. Because of the possibly more vulnerable colonic wall in acute inflammatory bowel disease, the air inflation for MDCTC should be performed most carefully to avoid any risk of colonic perforation. Conclusion: MDCTC may help to distinguish between patients with acute and chronic IBD. Especially extraintestinal complications, tumorous as well as pseudo-tumorous lesions can be detected with high sensitivity and specificity.

  6. CT colonography with limited bowel preparation: prospective assessment of patient experience and preference in comparison to optical colonoscopy with cathartic bowel preparation

    NARCIS (Netherlands)

    S. Jensch; S. Bipat; J. Peringa; A.H. de Vries; A. Heutinck; E. Dekker; L.C. Baak; A.D. Montauban van Swijndregt; J. Stoker

    2010-01-01

    The purpose of this study was to prospectively compare participant experience and preference of limited preparation computed tomography colonography (CTC) with full-preparation colonoscopy in a consecutive series of patients at increased risk of colorectal cancer. CTC preparation comprised 180 ml di

  7. PET/CT detection of incidental colorectal foci of F.D.G. uptake: Correlation with colonoscopy results;Decouverte fortuite de fixations colorectales focales du FDG en TEP/TDM: correlation aux donnees de la coloscopie

    Energy Technology Data Exchange (ETDEWEB)

    Nouira, M.; Evangelista, E.; Meignan, M.; Itti, E. [Universite Paris-12, Service de medecine nucleaire, hopital Henri-Mondor, AP-HP, 94 - Creteil (France); Sobhani, I. [Universite Paris-12, Service de gastroenterologie, hopital Henri-Mondor, AP-HP, 94 - Creteil (France); Hagege, H. [centre hospitalier intercommunal, Service de gastroenterologie, 94 - Creteil (France); Meignan, M.; Itti, E. [EAC CNRS 7054, 94 - Creteil (France)

    2010-04-15

    Purpose: F.D.G.-PET is an established tool for the diagnosis of recurrent or metastatic colorectal carcinoma. Several case series suggest that F.D.G.-PET often detects incidental adenomatous polyps or colorectal adenocarcinomas. The aim of this study was to correlate unexpected colorectal foci of F.D.G. uptake to pathology findings after systematic colonoscopy. Patients and methods: We reviewed the records of 3541 patients who underwent F.D.G. PET/CT in our institution over a 30-month period for the assessment of a known or suspected malignancy. In 85 of them, incidental, nodular shaped and well-circumscribed foci of abnormal uptake were identified in the area of the colon or rectum. Patients with segmental or diffuse abnormal colorectal uptake were excluded, as well as patients with known benign or malignant colorectal disease. Colonoscopy and complete pathology report was available in 29 patients. Maximal standardized uptake value (SUV{sub max}) was measured in all lesions. Results: Unexpected colorectal foci of F.D.G. uptake were associated with colonoscopic abnormalities in 23 patients (true positive rate: 79 %). Adenocarcinomas were found in six patients (SUV{sub max} = 7.3 +- 2.6), tubular adenomas in four patients (SUV{sub max} = 7.3 +- 4.9) and tubulovillous adenomas in 12 patients (SUV{sub max} = 4.2 +- 1.1). Hyperplasic polyps with no sign of dysplasia were found in the last patient (SUV{sub max} 3.3). Concomitant CT abnormalities were found on PET/CT fusion in eight patients and consisted of wall thickening (n = 5) or nodular mass (n = 3). Conversely, PET was falsely positive in six patients (21 %), with no concomitant CT abnormalities and no abnormal findings at endoscopy (SUV{sub max} 6.2 +- 2.8, no significant difference with true positive lesions). Conclusion: Our findings emphasize the need to perform a colonoscopy in front of incidental nodular colorectal foci of F.D.G. uptake because malignant or pre-malignant neoplasms, which are not clinically

  8. Evaluation of CT virtual intravascular endoscopy in fenestrated stent grafts: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Z. [Dept. of Imaging and Applied Physics, Curtin Univ. of Tech., Perth, WA (Australia); Allen, Y.; Fitzsimmons, B.; Hartely, D. [Cook R and D, WA (Australia); Lawrence-Brown, M. [Dept. of Public Health, Curtin Univ. of Tech., Perth, WA (Australia)

    2007-06-15

    We aim in this study to investigate the potential value of CT virtual intravascular endoscopy in patients diagnosed with abdominal aortic aneurysms undergoing fenestrated stent grafts. Both pre-and post-fenestration (within 3 months of implantation) multislice CT data were collected in eight patients and used for generation of virtual endoscopy images in our preliminary study. Variable fenestrations were deployed in 25 aortic branches with scallop fenestration implanted in six aortic ostia, large fenestration in four aortic ostia and small fenestration in 15 renal ostia, respectively. Measurements of the aortic ostia diameters both pre- and post-fenestration were successfully performed with virtual intravascular endoscopy visualization, and endovascular stents as well as their relationship to the aortic ostia were clearly demonstrated. Our results showed that there was no significant change of diameter of the aortic ostia following fenestrated stem grafts. Endovascular stents were clearly visualized on virtual endoscopy images, and no apparent deformity or malrotation was observed in this small group. Our preliminary study provides new insights into anatomic configuration/dimension of aortic ostia and endovascular stents, and virtual intravascular endoscopy could be a valuable technique to follow-up patients treated with fenestrated stent grafts. (orig.)

  9. Spiral CT pneumocolon: applications, status and limitations.

    Science.gov (United States)

    Harvey, C J; Renfrew, I; Taylor, S; Gillams, A R; Lees, W R

    2001-01-01

    CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit.

  10. Spiral CT pneumocolon: applications, status and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, C.J. [Department of Academic Imaging, University College London (United Kingdom); Department of Imaging, Hammersmith Hospital, London (United Kingdom); Renfrew, I.; Taylor, S.; Gillams, A.R.; Lees, W.R. [Department of Academic Imaging, University College London (United Kingdom)

    2001-09-01

    CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit. (orig.)

  11. CT virtual endoscopy and 3D stereoscopic visualisation in the evaluation of coronary stenting.

    Science.gov (United States)

    Sun, Z; Lawrence-Brown

    2009-10-01

    The aim of this case report is to present the additional value provided by CT virtual endoscopy and 3D stereoscopic visualisation when compared with 2D visualisations in the assessment of coronary stenting. A 64-year old patient was treated with left coronary stenting 8 years ago and recently followed up with multidetector row CT angiography. An in-stent restenosis of the left coronary artery was suspected based on 2D axial and multiplanar reformatted images. 3D virtual endoscopy was generated to demonstrate the smooth intraluminal surface of coronary artery wall, and there was no evidence of restenosis or intraluminal irregularity. Virtual fly-through of the coronary artery was produced to examine the entire length of the coronary artery with the aim of demonstrating the intraluminal changes following placement of the coronary stent. In addition, stereoscopic views were generated to show the relationship between coronary artery branches and the coronary stent. In comparison with traditional 2D visualisations, virtual endoscopy was useful for assessment of the intraluminal appearance of the coronary artery wall following coronary stent implantation, while stereoscopic visualisation improved observers' understanding of the complex cardiac structures. Thus, both methods could be used as a complementary tool in cardiac imaging.

  12. Utility of iodine overlay technique and virtual unenhanced images for the characterization of renal masses by dual-energy CT.

    Science.gov (United States)

    Song, Kyoung Doo; Kim, Chan Kyo; Park, Byung Kwan; Kim, Bohyun

    2011-12-01

    The objective of our study was to assess the utility of dual-energy CT for characterizing renal masses using iodine overlay techniques and virtual unenhanced images and to measure the potential radiation dose reduction for two-phase kidney CT compared with a standard three-phase protocol. Sixty patients with suspected renal masses underwent dual-energy CT including true unenhanced, dual-energy corticomedullary, and dual-energy late nephrographic phase imaging. Iodine overlay and virtual unenhanced images were derived from the corticomedullary and late nephrographic phases, respectively. The CT numbers of renal masses were calculated using the iodine overlay images superimposed on the virtual unenhanced images. The overall imaging quality of the true unenhanced images and of the virtual unenhanced images was also evaluated. The effective radiation doses for dual-energy CT and for true unenhanced imaging were calculated. For overlay or enhancement values on iodine overlay images, 36 simple cysts and 10 hemorrhagic cysts had an attenuation value of less than 20 HU, whereas 21 renal cell carcinomas showed an attenuation value of 20 HU or greater. Eleven angiomyolipomas contained macroscopic fat tissue. All renal masses were accurately classified on the basis of dual-energy CT. The imaging quality of the virtual unenhanced images from the corticomedullary and late nephrographic phases was inferior to the image quality of the true unenhanced images (p overlay techniques and virtual unenhanced images may be useful for characterizing renal masses.

  13. The Value of CT in Diagnosing Synchronous Colorectal Cancers Cases with Incomplete Colonoscopy%CT对结肠镜检查失败的同时多发大肠癌的诊断价值

    Institute of Scientific and Technical Information of China (English)

    程家乐; 彭佳远; 汪昱

    2013-01-01

    目的 评估CT在结肠镜检查不完全的同时多发大肠癌(SCRCs)中的诊断价值.方法 选取2002年1月至2011年8月期间在上海市第六人民医院行手术治疗大肠癌患者2123例的临床资料进行回顾性分析,根据是否完整地做完结肠镜检查分为完全组和不完全组.通过比较CT和病理结果 来计算CT诊断的灵敏度和特异度,并进一步分析影响CT结果 的因素.结果 CT确诊和漏诊的SCRCs患者分别为56例和36例.CT诊断的灵敏度和特异度不完全组分别为44.8%和93.6%;完全组分别为68.3%和97.0%.癌灶过小和癌灶毗邻是导致CT漏诊SCRCs的风险因子.结论 尽管CT简便易行,在诊断结肠镜检查失败的SCRCs中,其敏感性不高.当影响CT诊断的风险因素存在时,CT检查阴性的患者,应当做进一步检查,并密切随访.%Objective To assess the value of CT in diagnosing synchronous colorectal cancers( SCRCs ) cases with incomplete colonoscopy. Methods 2123 colorectal cancer patients admitted to the Sixth People's Hospital of Shanghai City from Jan. 2002 to Aug. 2011 treated by operation, were analyzed retrospectively in this research. The patients were divided into two groups according to whether complete colonoscopy was achieved, the complete group and the incomplete group. Then, CT results and final histological findings were compared to calculate the sensitivity and specificity. Factors affecting the detection of CT were further analyzed. Results Totally, 56 cases of SCRCs were identified by CT and 36 were missed. In the incomplete group,the sensitivity and specificity was 44.8% and 93.6% ,respectively,while the corresponding number of the complete group was 68.3% and 97.0% respectively. Small size of the tumors and foci adjacency of SCRCs were the risk factors causing the missed diagnosis. Methods Despite of the feasibility, CT had limited sensitivity in detecting SCRCs in patients with incomplete colonoscopy. Patients with negative CT results

  14. CT attenuation of colorectal polypoid lesions: evaluation of contrast enhancement in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Oto, Aytekin [Department of Radiology, Hacettepe University School of Medicine, Ankara (Turkey); Department of Radiology, University of Texas Medical Branch at Galveston, 301 University Boulevard, 77555-0709, Galveston, TX (United States); Gelebek, Veli; Oguz, Berna Sayan; Deger, Ahmet; Akhan, Okan; Besim, Aytekin [Department of Radiology, Hacettepe University School of Medicine, Ankara (Turkey); Sivri, Buelent [Department of Gastroenterology, Hacettepe University School of Medicine, Ankara (Turkey)

    2003-07-01

    The aim of this study was to calculate pre- and postcontrast CT attenuation values of benign colorectal polyp and carcinoma lesions detected by virtual colonoscopy, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid in the colon. Fifteen benign polyps and 21 colorectal carcinoma lesions detected by virtual colonoscopy in 18 patients were included in our study. All of the polyps and carcinoma lesions were confirmed by colonoscopic biopsy. Measurement of CT attenuation values was performed in precontrast (supine) and postcontrast (prone) scans for each polyp and carcinoma. The CT attenuation values of residual fluid in the colon was also measured from the same location before and after intravenous contrast administration. On unenhanced CT scan mean attenuation values of benign polyps and colorectal carcinomas were 32.4 and 42.6 HU, respectively. Following contrast enhancement, mean attenuation value increased to 78.9 HU for polyps and 90.7 HU for carcinomas. Increase in the CT attenuation values of these lesions was significant (p <0.0001). Mean CT attenuation value of residual fluid before and after administration of IV contrast were 14.6 and 13.8 HU, respectively. The difference between CT attenuation value of residual fluid in the colon before and after contrast material was not significant (p =0.29). Colorectal benign polyps and carcinomas demonstrate significant enhancement following contrast administration and use of intravenous contrast material during virtual colonoscopy may help in some cases in differentiating these solid lesions from residual colonic fluid that does not enhance. (orig.)

  15. Virtual endoscopy of the upper, central and peripheral airways with multirow detector CT; Virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege mit Mehrzeilen-Spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, H.; Dinkel, H.P.; Thoeny, H.; Vock, P. [Institut fuer Diagnostische Radiologie, Universitaetsspital Bern (Switzerland); Gugger, M. [Abteilung fuer Pneumologie, Universitaetsspital Bern (Switzerland)

    2002-09-01

    Virtual endoscopy of the upper, central and peripheral airways (virtual laryngoscopy or virtual bronchoscopy) produces endoluminal images similar to those of fiberoptic endoscopy. In particular, virtual endoscopy is useful for the assessment of endoluminal tumor extent and tracheobronchial stenosis. Especially since the introduction of multirow detector CT, high-resolution virtual-endoscopic images of the airways can be reconstructed. Either surface rendering or volume rendering can be used for realistic depiction of the airways. Semitransparent color-coded volume rendering is advantageous, because adjacent structures can be displayed in addition to endoluminal views. A major advantage of virtual endoscopy over fiberoptic endoscopy is its non-invasiveness. With virtual endoscopy, even a high-grade stenosis is passable, enabling evaluation of the distal airways. Disadvantages are its inability to depict mucosal color and to perform therapeutic maneuvers. In comparison to other CT display modes, virtual endoscopy allows a more realistic assessment of tracheobronchial stenosis than axial CT slices and multiplanar reformats. Virtual endoscopy of the airways can be used complementary to fiberoptic endoscopy before tracheotomy, stent implantation or lung resection and for post-operative follow-up. In the future, virtual airway endoscopy will be increasingly applied for interactive virtual reality guidance of airway procedures such as bronchoscopy and surgery. (orig.) [German] Die virtuelle Endoskopie der oberen, zentralen und peripheren Atemwege (virtuelle Laryngoskopie oder virtuelle Bronchoskopie) erzeugt eine der fiberoptischen Endoskopie vergleichbare Ansicht und kommt insbesondere zur Diagnostik von tracheobronchialen Stenosen und Tumoren mit endoluminaler Ausdehnung zur Anwendung. Vor allem seit Einfuehrung der Mehrzeilen-Spiral-CT lassen sich qualitativ hochwertige Rekonstruktionen der Atemwege erstellen. Das erfolgt entweder mittels Oberflaechenrekonstruktion

  16. CT arthrography and virtual arthroscopy in the diagnosis of the anterior cruciate ligament and meniscal abnormalities of the knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Whal; Chung, Jin-Wook; Kang, Heung-Sik; Hong, Sung-Hwan; Choi, Ja-Young [Seoul National University, Seoul (Korea, Republic of); Kim, Ho-Sung; Kim, Seok-Jung; Kim, Hyung-Ho [Aeromedical Center, Seoul (Korea, Republic of)

    2004-03-15

    To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology. Thirty-eight consecutive patients sho underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images. The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3%-96.7%, respectively and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3%-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively. CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.

  17. Splenic rupture following colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Juan Francisco Guerra; Ignacio San Francisco; Fernando Pimentel; Luis Ibanez

    2008-01-01

    Colonoscopy is a safe and routinely performed diagnostic and therapeutic procedure for different colorectal diseases. Although the most common complications are bleeding and perforation, extracolonic or visceral injuries have also been described. Splenic rupture is a rare complication following colonoscopy, with few cases reported. We report a 60-year-old female who presented to surgical consultation 8 h after a diagnostic colonoscopy. Clinical, laboratory and imaging findings were suggestive for a massive hemoperitoneum. At surgery, an almost complete splenic disruption was evident, and an urgent splenectomy was performed. After an uneventful postoperative period, she was discharged home. Splenic injury following colonoscopy is considered infrequent. Direct trauma and excessive traction of the splenocolic ligament can explain the occurrence of this complication. Many times the diagnosis is delayed because the symptoms are due to colonic insufflation, so the most frequent treatment is an urgent splenectomy. A high index of suspicion needs an early diagnosis and adequate therapy.

  18. Single-center study comparing computed tomography colonography with conventional colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Ian C Roberts-Thomson; Graeme R Tucker; Peter J Hewett; Peter Cheung; Ruben A Sebben; EE Win Khoo; Julie D Marker; Wayne K Clapton

    2008-01-01

    AIM: To compare the results from computed tomography (CT) colonography with conventional colonoscopy in symptomatic patients referred for colonoscopy. METHODS: The study included 227 adult outpatients, mean age 60 years, with appropriate indications for colonoscopy. CT colonography and colonoscopy were performed on the same day in a metropolitan teaching hospital. Colonoscopists were initially blinded to the results of CT colonography but there was segmental unblinding during the procedure. The primary outcome measures were the sensitivity and specificity of CT colonography for the identification of polyps seen at colonoscopy (i.e. analysis by polyp). Secondary outcome measures included an analysis by patient, extracolonic findings at CT colonography, adverse events with both procedures and patient acceptance and preference. RESULTS: Twenty-five patients (11%) were excluded from the analysis because of incomplete colonoscopy or poor bowel preparation that affected either CT colonography, colonoscopy or both procedures. Polyps and masses (usually cancers) were detected at colonoscopy and CT colonography in 35% and 42% of patients, respectively. Of nine patients with a final diagnosis of cancer, eight (89%) were identified by CT colonography as masses (5) or polyps (3). For polyps analyzed according to polyp, the overall sensitivity of CT colonography was 50% (95% CI, 39%-61%) but this increased to 71% (95% CI, 52%-85%) for polyps ≥ 6 mm in size. Similarly, specificity for all polyps was 48% (95% CI, 39%-58%) increasing to 67% (95% CI, 56%-76%) for polyps ≥ 6 mm. Adverse events were uncommon but included one colonic perforation at colonoscopy, Patient acceptance was high for both procedures but preference favoured CT colonography. CONCLUSION: Although CT colonography was more sensitive in this study than in some previous studies, the procedure is not yet sensitive enough for widespread application in symptomatic patients.

  19. Preoperative RFA simulation for liver cancer using a CT virtual ultrasound system

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Kosei [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Moriyasu, Fuminori [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan)]. E-mail: moriyasu@tokyo-med.ac.jp; Mine, Yoshitaka [R and D, Toshiba Medical Systems Co., Tokyo (Japan); Miyata, Yuki [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Sugimoto, Katsutoshi [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Metoki, Ryou [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Kamamoto, Hiroyuki [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Suzuki, Shirou [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Shimizu, Masafumi [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Miyahara, Takeo [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Yokoi, Masato [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Horibe, Toshiya [Fourth Department of Gastroenterology and Hepatology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjukuku-ku, Tokyo 160-0023 (Japan); Yamagata, Hitoshi [R and D, Toshiba Medical Systems Co., Tokyo (Japan)

    2007-02-15

    We developed a computed tomography (CT) virtual ultrasound system (CVUS) as an imaging system to support treatment under percutaneous ultrasound (US) guidance. This prototype clinical system, produced in collaboration with Tokyo Medical University, uses display software developed by Toshiba Medical Systems. We examined the utility of this system by scheduling treatment plans preoperatively and simulating puncture and radiofrequency ablation (RFA) for liver cancer. The study enrolled 51 liver cancer patients with 66 nodules 0.8-8 cm in diameter in which RFA was performed between June 2004 and December 2004. Virtual US and multiplanar reconstruction (MPR) images were constructed on the basis of DICOM CT data and puncture and ablation of liver cancer were simulated. The following were evaluated: (1) how to avoid complications and determine an appropriate puncture route by simulating puncture with C-mode MPR images; (2) determination of the three-dimensional location of the tumor for ablation, as well as the adjacent organs and vessels, by MPR rotation 360{sup o} around the center of the tumor (center lock); and (3) how to determine the center and volume of ablation and avoid injuries to nearby organs and vessels by simulating ablation procedures. C -mode MPR images were effective for (1) determining and modifying the puncture route in 35 of 51 cases (69.6%) and (2) determining the spatial location of vessels and nearby organs in 50 of 51 cases (98.0%) by the center lock; and (3) simulating the ablation helped determine the center and volume of ablation by avoiding injuries to vessels and nearby organs in 45 or 51 cases (88.2%). Taken together, the CVUS allowed easy simulation of local treatment of liver cancer under US guidance using CT data alone and the preoperative simulation predicted an improvement in the safety of local therapy of liver cancer.

  20. Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation.

    Science.gov (United States)

    Barnes, Daniel; Gutiérrez Chacoff, José; Benegas, Mariana; Perea, Rosario J; de Caralt, Teresa M; Ramirez, José; Vollmer, Ivan; Sanchez, Marcelo

    2017-04-01

    To describe the imaging features of the central airway pathology, correlating the findings with those in pathology and virtual endoscopy. To propose a schematic and practical approach to reach diagnoses, placing strong emphasis on multidetector computed tomography (MDCT) findings. We reviewed our thoracic pathology database and the central airway pathology-related literature. Best cases were selected to illustrate the main features of each disease. MDCT was performed in all cases. Multiplanar and volume-rendering reconstructions were obtained when necessary. Virtual endoscopy was obtained from the CT with dedicated software. Pathological conditions affecting the central airways are a heterogeneous group of diseases. Focal alterations include benign neoplasms, malignant neoplasms, and non-neoplastic conditions. Diffuse abnormalities are divided into those that produce dilation and those that produce stenosis and tracheobronchomalacia. Direct bronchoscopy (DB) visualises the mucosal layer and is an important diagnostic and therapeutic weapon. However, assessing the deep layers or the adjacent tissue is not possible. MDCT and post-processing techniques such as virtual bronchoscopy (VB) provide an excellent evaluation of the airway wall. This review presents the complete spectrum of the central airway pathology with its clinical, pathological and radiological features. • Dividing diseases into diffuse and focal lesions helps narrow the differential diagnosis. • Focal lesions with nodularity are more likely to correspond to tumours. • Focal lesions with stenosis are more likely to correspond to inflammatory disease. • Posterior wall involvement is the main feature in diffuse lesions with stenosis.

  1. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine ...

  2. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine ...

  3. Role of computed tomographic colonoscopy of postoperative surveillance in patient with gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Dae Won Jun; Dong Hoo Lee; Oh Young Lee; Hyun Chul Lim; Sung Joon Kwon; Hang Lak Lee; Byung Chul Yoon; Ho Soon Choi; Joon Soo Hahm; Min Ho Lee

    2007-01-01

    AIM: To examine the diagnostic yield of colorectal neoplasia at computed tomographic colonoscopy (CTC) as well as the feasibility of contrast enhanced CTC in patients with gastric cancer.METHODS: To examine the incidence of colon polyp we selected postoperative 188 gastric cancer patients, which we refer to as the 'colon polyp survey group'. To examine the feasibility of CTC for early detection of colon cancer or advanced colon adenoma, we selected 47 gastric cancer patients (M:F 29:18, mean age 53.8 years), which we call the 'CT colonoscopy group'. All the 47 patients underwent successive CTC and colonoscopy on the same day.RESULTS: Totally 109 colon polyps were observed from 59 out of 188 gastric cancer patients, the incidence rate of colon polyps in gastric cancer patients being 31.4%. The sensitivity of CTC in detecting individuals with at least 1 lesion of any size was 57.1%, the specificity was 72.7%, the positive predictive value was 47.1%, and the negative predictive value was 71.9%. When the cutoff size was decreased to 6 mm, the sensitivity and specificity were 80.0% and 92.9%, respectively, with positive and negative predictive values of 57.1% and 97.5%, respectively. Only one patient was classified as false negative by virtual colonoscopy.CONCLUSION: The diagnostic yield of colorectal polyp was 31.4% in patients with gastric cancer, and contrast enhanced CTC is an acceptable tool for the detection of synchronous colorectal advanced adenoma and postoperative surveillance of gastric cancer patients.

  4. An international review of the main cost-effectiveness drivers of virtual colonography versus conventional colonoscopy for colorectal cancer screening: Is the tide changing due to adherence?

    Energy Technology Data Exchange (ETDEWEB)

    Kriza, Christine, E-mail: Christine.kriza@uk-erlangen.de [Interdisciplinary Centre for Health Technology Assessment and Public Health, University of Erlangen-Nuremberg, National BMBF-Cluster of Excellence, “Medical Technologies - Medical Valley EMN”, Schwabachanlage 6, 91054 Erlangen (Germany); Emmert, Martin, E-mail: Martin.Emmert@fau.de [School of Business and Economics, Institute of Management, University of Erlangen-Nuremberg, Lange Gasse 20, 90403 Nuremberg (Germany); Wahlster, Philip, E-mail: Philip.wahlster@uk-erlangen.de [Interdisciplinary Centre for Health Technology Assessment and Public Health, University of Erlangen-Nuremberg, National BMBF-Cluster of Excellence, “Medical Technologies - Medical Valley EMN”, Schwabachanlage 6, 91054 Erlangen (Germany); Niederländer, Charlotte, E-mail: Charlotte.niederlaender@uk-erlangen.de [Interdisciplinary Centre for Health Technology Assessment and Public Health, University of Erlangen-Nuremberg, National BMBF-Cluster of Excellence, “Medical Technologies - Medical Valley EMN”, Schwabachanlage 6, 91054 Erlangen (Germany); Kolominsky-Rabas, Peter, E-mail: Peter.kolominsky@uk-erlangen.de [Interdisciplinary Centre for Health Technology Assessment and Public Health, University of Erlangen-Nuremberg, National BMBF-Cluster of Excellence, “Medical Technologies - Medical Valley EMN”, Schwabachanlage 6, 91054 Erlangen (Germany)

    2013-11-01

    Objectives: The majority of recent cost-effectiveness reviews concluded that computerised tomographic colonography (CTC) is not a cost-effective colorectal cancer (CRC) screening strategy yet. The objective of this review is to examine cost-effectiveness of CTC versus optical colonoscopy (COL) for CRC screening and identify the main drivers influencing cost-effectiveness due to the emergence of new research. Methods: A systematic review was conducted for cost-effectiveness studies comparing CTC and COL as a screening tool and providing outcomes in life-years saved, published between January 2006 and November 2012. Results: Nine studies were included in the review. There was considerable heterogeneity in modelling complexity and methodology. Different model assumptions and inputs had large effects on resulting cost-effectiveness of CTC and COL. CTC was found to be dominant or cost-effective in three studies, assuming the most favourable scenario. COL was found to be not cost effective in one study. Conclusions: CTC has the potential to be a cost-effective CRC screening strategy when compared to COL. The most important assumptions that influenced the cost-effectiveness of CTC and COL were related to CTC threshold-based reporting of polyps, CTC cost, CTC sensitivity for large polyps, natural history of adenoma transition to cancer, AAA parameters and importantly, adherence. There is a strong need for a differential consideration of patient adherence and compliance to CTC and COL. Recent research shows that laxative-free CTC screening has the potential to become a good alternative screening method for CRC as it can improve patient uptake of screening.

  5. Tin-filter enhanced dual-energy-CT: image quality and accuracy of CT numbers in virtual noncontrast imaging.

    Science.gov (United States)

    Kaufmann, Sascha; Sauter, Alexander; Spira, Daniel; Gatidis, Sergios; Ketelsen, Dominik; Heuschmid, Martin; Claussen, Claus D; Thomas, Christoph

    2013-05-01

    To measure and compare the objective image quality of true noncontrast (TNC) images with virtual noncontrast (VNC) images acquired by tin-filter-enhanced, dual-source, dual-energy computed tomography (DECT) of upper abdomen. Sixty-three patients received unenhanced abdominal CT and enhanced abdominal DECT (100/140 kV with tin filter) in portal-venous phase. VNC images were calculated from the DECT datasets using commercially available software. The mean attenuation of relevant tissues and image quality were compared between the TNC and VNC images. Image quality was rated objectively by measuring image noise and the sharpness of object edges using custom-designed software. Measurements were compared using Student two-tailed t-test. Correlation coefficients for tissue attenuation measurements between TNC and VNC were calculated and the relative deviations were illustrated using Bland-Altman plots. Mean attenuation differences between TNC and VNC (HUTNC - HUVNC) image sets were as follows: right liver lobe -4.94 Hounsfield units (HU), left liver lobe -3.29 HU, vena cava -2.19 HU, spleen -7.46 HU, pancreas 1.29 HU, fat -11.14 HU, aorta 1.29 HU, bone marrow 36.83 HU (all P Mean image noise was significantly higher in TNC images (P images (P = .19). The Hounsfield units in VNC images closely resemble TNC images in the majority of the organs of the upper abdomen (kidneys, liver, pancreas). In spleen and fat, Hounsfield numbers in VNC images are tend to be higher than in TNC images. VNC images show a low image noise and satisfactory edge sharpness. Other criteria of image quality and the depiction of certain lesions need to be evaluated additionally. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  6. Splenic injury after colonoscopy

    DEFF Research Database (Denmark)

    Petersen, C.R.; Adamsen, S.; Gocht-Jensen, P.

    2008-01-01

    Splenic injury is a rare and serious complication of colonoscopy. The most likely mechanism is tension on the splenocolic ligament and adhesions. Eight cases were identified among claims for compensation submitted to the Danish Patient Insurance Association during the period 1992-2006, seven...... the colonoscopy, ranging from 4 hours to 7 days, before presenting with signs of splenic injury. In all cases the spleen was torn, and the amount of blood in the peritoneal cavity ranged from 1500 mL to 5000 mL. Two patients died postoperatively. The number of cases reported after 2000 indicates...

  7. Comparison of virtual unenhanced CT images of the abdomen under different iodine flow rates.

    Science.gov (United States)

    Li, Yongrui; Li, Ye; Jackson, Alan; Li, Xiaodong; Huang, Ning; Guo, Chunjie; Zhang, Huimao

    2017-01-01

    To assess the effect of varying iodine flow rate (IFR) and iodine concentration on the quality of virtual unenhanced (VUE) images of the abdomen obtained with dual-energy CT. 94 subjects underwent unenhanced and triphasic contrast-enhanced CT scan of the abdomen, including arterial phase, portal venous phase, and delayed phase using dual-energy CT. Patients were randomized into 4 groups with different IFRs or iodine concentrations. VUE images were generated at 70 keV. The CT values, image noise, SNR and CNR of aorta, portal vein, liver, liver lesion, pancreatic parenchyma, spleen, erector spinae, and retroperitoneal fat were recorded. Dose-length product and effective dose for an examination with and without plain phase scan were calculated to assess the potential dose savings. Two radiologists independently assessed subjective image quality using a five-point scale. The Kolmogorov-Smirnov test was used first to test for normal distribution. Where data conformed to a normal distribution, analysis of variance was used to compare mean HU values, image noise, SNRs and CNRs for the 4 image sets. Where data distribution was not normal, a nonparametric test (Kruskal-Wallis test followed by stepwise step-down comparisons) was used. The significance level for all tests was 0.01 (two-sided) to allow for type 2 errors due to multiple testing. The CT numbers (HU) of VUE images showed no significant differences between the 4 groups (p > 0.05) or between different phases within the same group (p > 0.05). VUE images had equal or higher SNR and CNR than true unenhanced images. VUE images received equal or lower subjective image quality scores than unenhanced images but were of acceptable quality for diagnostic use. Calculated dose-length product and estimated dose showed that the use of VUE images in place of unenhanced images would be associated with a dose saving of 25%. VUE images can replace conventional unenhanced images. VUE images are not affected by varying iodine

  8. Role of CT colonography in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Regge, Daniele [Institute for Cancer Research and Treatment, Candiolo, Turin (Italy)], E-mail: dregge@mauriziano.it; Neri, Emanuele; Turini, Francesca [Diagnostic and Interventional Radiology, University of Pisa (Italy); Chiara, Gabriele [Institute for Cancer Research and Treatment, Candiolo, Turin (Italy)

    2009-03-15

    CT colonography (CTC), or virtual colonoscopy, is a non-invasive imaging method that uses CT data sets combined with specialized imaging software to examine the colon. CTC is not used routinely in patients with inflammatory bowel disease (IBD). However, investigating contemporarily the colon, other abdominal organs and the peritoneum with CTC is at times useful in patients with IBD, especially when other diagnostic tools fail. Furthermore, since symptoms of colorectal cancer sometimes superimpose to those of inflammatory disease, it may happen to image patients with IBD incidentally. If clinical signs are suggestive for inflammatory disease, exam technique should be modified accordingly and distinguishing radiological findings searched for.

  9. Iatrogenic Sinistral Hypertension Complicating Screening Colonoscopy

    Directory of Open Access Journals (Sweden)

    Oliver J. Ziff

    2013-01-01

    Full Text Available Colonoscopy is widely accepted as the gold-standard screening technique for detecting malignancies in the distal gastrointestinal tract in patients with symptoms suggestive of colon cancer. However, this procedure is not without risk, including colonic perforation. We report a patient who was managed conservatively after colonoscopy induced perforation. Eighteen months after appearing to make a full recovery, he presented with an upper gastrointestinal bleed. Oesophago-gastro-duodenoscopy (OGD revealed large gastric fundal varices and computed tomography (CT revealed splenic vein thrombosis. The ensuing left-sided (sinistral hypertension explains the development of the fundal varices in the presence of normal liver function. At surgery, a persistent abscess cavity was identified and cultures from this site grew Streptococcus anginosus. Curative splenectomy was performed and the patient made a full recovery. We advocate more prompt operative intervention in selected cases of iatrogenic colonic perforation with primary repair to prevent late complications.

  10. Conventional colonoscopy; Konventionelle Kolonoskopie

    Energy Technology Data Exchange (ETDEWEB)

    Haefner, M. [Universitaetsklinik fuer Innere Medizin III, Klinische Abteilung fuer Gastroenterologie und Hepatologie, Wien (Austria)

    2008-02-15

    In the last 40 years colonoscopy has been the gold standard in diagnosis of conditions affecting the large intestine. We see its main disadvantages in the necessity for intestinal preparation and in the pain not infrequently experienced by patients who are not sedated. Widespread use of sedation has made it possible to improve patient acceptance in recent years. Complications of colonoscopy are rare, and even the removal of large polyps is regarded as a safe procedure. One of the main problems of colonoscopy is that a large number of far from trivial polyps - up to 20% in the literature - are overlooked. New developments, such as higher resolution videochips and chromoendoscopy, lead to a better diagnostic yield, especially of flat lesions. The rapidly developing sector of interventional colonoscopy in particular will ensure that colonoscopy continues to have an important place in the management of illnesses affecting the large intestine. (orig.) [German] Die Kolonoskopie war in den letzten 40 Jahren der Goldstandard zur Diagnostik von Dickdarmerkrankungen. Ihre Hauptnachteile liegen in der Notwendigkeit der Darmvorbereitung sowie nicht selten auftretenden Schmerzen beim nichtsedierten Patienten. Durch den breiten Einsatz der Sedierung konnte in den letzten Jahren die Patientenakzeptanz verbessert werden. Komplikationen der Kolonoskopie sind selten und selbst das Entfernen grosser Polypen wird als sicher angesehen. Eines der Hauptprobleme der Kolonoskopie liegt in der nicht unbetraechtlichen Anzahl uebersehener Polypen, die in der Literatur bis zu 20% betraegt. Neue Entwicklungen wie hoeher aufloesende Videochips oder die Chromoendoskopie fuehren zu einer verbesserten diagnostischen Ausbeute v. a. flacher Laesionen. Besonders das sich rasch entwickelnde Gebiet der interventionellen Kolonoskopie wird dafuer sorgen, dass die Kolonoskopie auch in Zukunft noch einen wichtigen Stellenwert beim Management von Dickdarmerkrankungen hat. (orig.)

  11. Development of virtual CT DICOM images of patients with tumors: application for TPS and Monte Carlo dose evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Milian, F. M.; Attili, A.; Russo, G; Marchetto, F.; Cirio, R., E-mail: felix_mas_milian@yahoo.com, E-mail: attili@to.infn.it, E-mail: russo@to.infn.it, E-mail: fmarchet@to.infn.it, E-mail: cirio@to.infn.it [Istituto Nazionale di Fisica Nucleare (INFN), Torino, TO (Italy); Bourhaleb, F., E-mail: bourhale@to.infn.it [Universita di Torino (UNITO), Torino, TO (Italy)

    2013-07-01

    A novel procedure for the generation of a realistic virtual Computed Tomography (CT) image of a patient, using the advanced Boundary RE Presentation (BREP)-based model MASH, has been implemented. This method can be used in radiotherapy assessment. It is shown that it is possible to introduce an artificial cancer, which can be modeled using mesh surfaces. The use of virtual CT images based on BREP models presents several advantages with respect to CT images of actual patients, such as automation, control and flexibility. As an example, two artificial cases, namely a brain and a prostate cancer, were created through the generation of images and tumor/organ contours. As a secondary objective, the described methodology has been used to generate input files for treatment planning system (TPS) and Monte Carlo code dose evaluation. In this paper, we consider treatment plans generated assuming a dose delivery via an active proton beam scanning performed with the INFN-IBA TPS kernel. Additionally, Monte Carlo simulations of the two treatment plans were carried out with GATE/GEANT4. The work demonstrates the feasibility of the approach based on the BREP modeling to produce virtual CT images. In conclusion, this study highlights the benefits in using digital phantom model capable of representing different anatomical structures and varying tumors across different patients. These models could be useful for assessing radiotherapy treatment planning systems (TPS) and computer simulations for the evaluation of the adsorbed dose. (author)

  12. Deep transfer learning of virtual endoluminal views for the detection of polyps in CT colonography

    Science.gov (United States)

    Näppi, Janne J.; Hironaka, Toru; Regge, Daniele; Yoshida, Hiroyuki

    2016-03-01

    Proper training of deep convolutional neural networks (DCNNs) requires large annotated image databases that are currently not available in CT colonography (CTC). In this study, we employed a deep transfer learning (DETALE) scheme to circumvent this problem in automated polyp detection for CTC. In our method, a DCNN that had been pre-trained with millions of non-medical images was adapted to identify polyps using virtual endoluminal images of the polyp candidates prompted by a computer-aided detection (CADe) system. For evaluation, 154 CTC cases with and without fecal tagging were divided randomly into a development set and an external validation set including 107 polyps >=6 mm in size. A CADe system was trained to detect polyp candidates using the development set, and the virtual endoluminal images of the polyp candidates were labeled manually into true-positive and several false-positive (FP) categories for transfer learning of the DCNN. Next, the trained CADe system was used to detect polyp candidates from the external validation set, and the DCNN reviewed their images to determine the final detections. The detection sensitivity of the standalone CADe system was 93% at 6.4 FPs per patient on average, whereas the DCNN reduced the number of FPs to 2.0 per patient without reducing detection sensitivity. Most of the remaining FP detections were caused by untagged stool. In fecal-tagged CTC cases, the detection sensitivity was 94% at only 0.78 FPs per patient on average. These preliminary results indicate that DETALE can yield substantial improvement in the accuracy of automated polyp detection in CTC.

  13. Acceptability of virtual unenhanced CT of the aorta as a replacement for the conventional unenhanced phase

    Energy Technology Data Exchange (ETDEWEB)

    Shaida, N., E-mail: nadeem.shaida@addenbrookes.nhs.uk [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Bowden, D.J.; Barrett, T.; Godfrey, E.M.; Taylor, A.; Winterbottom, A.P.; See, T.C. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Lomas, D.J. [Department of Radiology, University of Cambridge, Addenbrooke' s Hospital, Cambridge (United Kingdom); Shaw, A.S. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2012-05-15

    Aim: To evaluate whether virtual unenhanced (VU) computed tomography (CT) images generated of the aorta were of sufficient quality to replace the conventional unenhanced (CU) images. Materials and methods: Forty-nine patients undergoing examination of the thoracic or abdominal aorta were examined using a dual-energy protocol. VU images were generated from the arterial phase images and compared to the CU images. Objective analysis was performed by drawing paired regions of interest (ROIs) within the thoracic and abdominal aorta and measuring the radiodensity in Hounsfield units attenuation within the ROIs. Subjective analysis was performed by two experienced readers evaluating the VU images in terms of noise, quality, calcium loss, and overall acceptability. Results: The attenuation was significantly higher in the VU images compared to the CU images within the thoracic aorta (p < 0.01) but not within the abdominal aorta (p = 0.15). Overall the VU images of the abdominal aorta were deemed acceptable as replacements for the CU images in 93% of cases. For the thoracic aorta, the VU images were deemed acceptable in only 12% of cases, primarily due to pulsation artefact. Conclusion: VU images of the abdominal aorta are acceptable as replacements for the CU images in the vast majority of cases; however, they are not suitable as replacements for the CU images of the thoracic aorta.

  14. Indications for and results of CT colonography: from screening to the symptomatic patient; Indikationen und Ergebnisse der CT-Kolonographie: von der Vorsorge bis zum symptomatischen Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Graser, A.; Becker, C.R.; Reiser, M.F. [Klinikum Grosshadern der LMU Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Mang, T. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, AKH Wien, Wien (Austria)

    2008-02-15

    CT colonography (CTC) is also referred to as virtual colonoscopy and is being used with increasing frequency in radiological practice. While there are still no generally accepted, clear-cut indications for its use in mass colorectal cancer screening, there is evidence that this investigation is useful in patients in whom colonoscopy has not been successful or who have known stenotic lesions in the colon. Recent results of significant comparative studies of CTC and conventional colonoscopy will have some influence on the future place of CTC in screening for cancer of the bowel; they show the great potential of CT-aided bowel examination. (orig.) [German] Die CT-Kolonographie (CTK), auch als virtuelle Koloskopie bezeichnet, wird zunehmend in der radiologischen Praxis eingesetzt. Waehrend fuer die reine Vorsorgeuntersuchung z. Z. noch keine rechtfertigende Indikation besteht, koennen symptomatische Patienten nach fehlgeschlagener Koloskopie oder zur Beurteilung des Darms proximal einer Stenose mittels CTK untersucht werden. Ergebnisse wichtiger Studien, die die CT-Kolonographie mit der herkoemmlichen Koloskopie vergleichen, beeinflussen die zukuenftige Position der Untersuchungsmethode beim Darmkrebsscreening. Vergleichsstudien mit der Koloskopie zeigen das grosse Potenzial der CT-gestuetzten Darmuntersuchung. (orig.)

  15. Quantitative analysis of the dual-energy CT virtual spectral curve for focal liver lesions characterization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi, E-mail: wq20@hotmail.com; Shi, Gaofeng, E-mail: gaofengs62@sina.com; Qi, Xiaohui, E-mail: qixiaohui1984@163.com; Fan, Xueli, E-mail: 407849960@qq.com; Wang, Lijia, E-mail: 893197597@qq.com

    2014-10-15

    Highlights: • We establish a feasible method using the virtual spectral curves (VSC) to differentiate focal liver lesions using DECT. • Our study shows the slope of the VSC can be used to differentiate between hemangioma, HCC, metastasis and cyst. • Importantly, the diagnostic specificities associated with using the slope to diagnose both hemangioma and cysts were 100%. - Abstract: Objective: To assess the usefulness of the spectral curve slope of dual-energy CT (DECT) for differentiating between hepatocellular carcinoma (HCC), hepatic metastasis, hemangioma (HH) and cysts. Methods: In total, 121 patients were imaged in the portal venous phase using dual-energy mode. Of these patients, 23 patients had HH, 28 patients had HCC, 40 patients had metastases and 30 patients had simple cysts. The spectral curves of the hepatic lesions were derived from the 40–190 keV levels of virtual monochromatic spectral imaging. The spectral curve slopes were calculated from 40 to 110 keV. The slopes were compared using the Kruskal–Wallis test. Receiver operating characteristic curves (ROC) were used to determine the optimal cut-off value of the slope of the spectral curve to differentiate between the lesions. Results: The spectral curves of the four lesion types had different baseline levels. The HH baseline level was the highest followed by HCC, metastases and cysts. The slopes of the spectral curves of HH, HCC, metastases and cysts were 3.81 ± 1.19, 1.49 ± 0.57, 1.06 ± 0.76 and 0.13 ± 0.17, respectively. These values were significantly different (P < 0.008). Based on ROC analysis, the respective diagnostic sensitivity and specificity were 87% and 100% for hemangioma (cut-off value ≥ 2.988), 82.1% and 65.9% for HCC (cut-off value 1.167–2.998), 65.9% and 59% for metastasis (cut-off value 0.133–1.167) and 44.4% and 100% for cysts (cut-off value ≤ 0.133). Conclusion: Quantitative analysis of the DECT spectral curve in the portal venous phase can be used to

  16. USING OF MULTISLICE HELICAL CT COLONOGRAPHY IN PATIENTS WITH MALIGNANT LESIONS OF COLON

    Institute of Scientific and Technical Information of China (English)

    Ming-wei Qin; Wei-dong Pan; Guan-ning Cong; Yun Wang; Yun-qing Zhang; Wen-bin Mou; Zheng-yu Jin

    2005-01-01

    Objective To investigate the techniques and clinical applications of multislice helical computed tomography (CT) colono graphy in colonic lesions. Methods Fifty-nine patients with malignant lesions of colon underwent volume scanning using multislice helical CT. Four types of reconstruction including CT virtual colonoscopy (CTVC), shaded surface display (SSD), Raysum, and mu ltiple planar reconstruction (MPR) were used for image post-processing. The results were compared with those of colonos copy and pathology. Results Multislice helical CT colonography detected 54 colorectal carcinomas, 4 adenomas with focal carcinoma, 1 non-Hodgkin's lymphoma (NHL). The lesions' number, size, location, morphology, stricture of intestinal cavity, infiltration, and metastasis were shown satisfactorily by multislice helical CT colonography. Whole colon could be shown in all patients. CT colonography displayed 4 synchronous colonic tumors, 1 ascending colon carcinoma combined with left renal carcinoma among 54 patients with colonic carcinomas. The accuracy of location of CT colonography was 100%. There were 9 cases that CT showed the tumor location was different from the finding of conventional colonoscopy, while all of the CT location were proven exact by operation. CT colonography also displayed the infiltration of serous layer and fatty tissue in 45 cases; 21 cases matched the pathological results in all the 24 cases of suspicious lymph node metastasis, the sensitivity was 87.5%, the specificity was 90.6%; 9 cases hepatic metastasis, 2 ovarian metastasis, and 1 double adrenal gland metastasis.Conclusions Multislice helical CT colonography is effective in preoperative diagnosis, location, stage, and making treatment plan of colorectal carcinoma. It can display the portion not seen during colonoscopy and may have an adjunctive role.

  17. Detection of Bone Marrow Edema in Nondisplaced Hip Fractures: Utility of a Virtual Noncalcium Dual-Energy CT Application.

    Science.gov (United States)

    Kellock, Trenton T; Nicolaou, Savvas; Kim, Sandra S Y; Al-Busaidi, Sultan; Louis, Luck J; O'Connell, Tim W; Ouellette, Hugue A; McLaughlin, Patrick D

    2017-09-01

    Purpose To quantify the sensitivity and specificity of dual-energy computed tomographic (CT) virtual noncalcium images in the detection of nondisplaced hip fractures and to assess whether obtaining these images as a complement to bone reconstructions alters sensitivity, specificity, or diagnostic confidence. Materials and Methods The clinical research ethics board approved chart review, and the requirement to obtain informed consent was waived. The authors retrospectively identified 118 patients who presented to a level 1 trauma center emergency department and who underwent dual-energy CT for suspicion of a nondisplaced traumatic hip fracture. Clinical follow-up was the standard of reference. Three radiologists interpreted virtual noncalcium images for traumatic bone marrow edema. Bone reconstructions for the same cases were interpreted alone and then with virtual noncalcium images. Diagnostic confidence was rated on a scale of 1 to 10. McNemar, Fleiss κ, and Wilcoxon signed-rank tests were used for statistical analysis. Results Twenty-two patients had nondisplaced hip fractures and 96 did not have hip fractures. Sensitivity with virtual noncalcium images was 77% and 91% (17 and 20 of 22 patients), and specificity was 92%-99% (89-95 of 96 patients). Sensitivity increased by 4%-5% over that with bone reconstruction images alone for two of the three readers when both bone reconstruction and virtual noncalcium images were used. Specificity remained unchanged (99% and 100%). Diagnostic confidence in the exclusion of fracture was improved with combined bone reconstruction and virtual noncalcium images (median score: 10, 9, and 10 for readers 1, 2, and 3, respectively) compared with bone reconstruction images alone (median score: 9, 8, and 9). Conclusion When used as a supplement to standard bone reconstructions, dual-energy CT virtual noncalcium images increased sensitivity for the detection of nondisplaced traumatic hip fractures and improved diagnostic confidence in

  18. CT VIRTUAL ENDOSCOPY IN ASSESSING OSSICULAR CHAIN DISRUPTION CSUSED BY TEMPORAL BONE FRACTURE AND EAR TRAUMA

    Institute of Scientific and Technical Information of China (English)

    JIANG Lixin; XIAO Zhiwen

    2013-01-01

    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 us-ing 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 sublux-ation on VE, and no facial paralysis were treated conservatively for 4-12 weeks with repeated hearing evalu-ation; those with facial paralysis underwent surgery if no recovery after 4-8 weeks of conservative treat-ment. 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 pa-ralysis. VE, audiological tests and facial nerve function tests were repeated in 3-6 months after surgery. Re-sults Of the 6 cases with mild conductive hearing loss, ossicular chain subluxation and no facial paralysis, 3 recovered 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 House-Brackmann (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

  19. Spiral CT arthrography of multiplanar reconstruction and virtual arthroscopy technique in diagnosis of knee with internal derangements

    Institute of Scientific and Technical Information of China (English)

    熊传芝; 郝敬明

    2004-01-01

    5Objective:To evaluate the values of spiral CT arthrography with multiplanar reconstruction and virtual arthroscopy technique in diagnosis of internal derangements of the knee. Methods:Ten bovine knees were used for experiment. The menisci, anterior and posterior cruciate ligaments and cartilage of these 10 bovine knees were injured with a hook. Each of the joints was injected with 100 mi air, then soon scanned with a PQ6000 spiral computed tomography scanner. The data obtained was input into the work station, and multiplanar reconstruction technique was used to illustrate lesions in the knees. The results of CT diagnosis were compared to those found by gross inspection of the specimens. Clinically, 10 knees of 9 patients diagnosed as internal derangement were evaluated with the same method after 50-70 ml air was injected into each of the joints. Nine months later, the data of 2 patients were used for CT endoscopy reconstruction. The results were compared with intraoperative findings. Results:Experimentally,the sensitivity and specificity were 88.9% and 93.9% by detection of meniscal abnormalities, 85.7% and 100% by detection of cruciate ligament lesions, and 72.7% and 100% by detection of cartilage damage, respectively. Clinically, the sensitivity and specificity were 90. 0% and 95.0% by detection of meulscal lesion. As to ligament, the figures were 85.7% and 100% respectively. Images of virtual arthroscopy simulated the images of real arthroscopy. Conclnsious:Spiral CT arthrography of multiplanar reconstruction technique offers fime images of internal structures of the knee, with clear border and internal structure. It is an accurate method for detecting meulscal, cruciate and collateral ligament and cartilaginous lesions that cause internal derangement of the knee.Virtual arthroscopy technique is a hopeful method for detecting reasons of derangement of the knee.

  20. Comparison of Virtual Unenhanced Images Derived From Dual-Energy CT With True Unenhanced Images in Evaluation of Gallstone Disease.

    Science.gov (United States)

    Lee, Han A; Lee, Young Hwan; Yoon, Kwon-Ha; Bang, Dong-Ho; Park, Dong Eun

    2016-01-01

    The aim of this study was to compare gallstones on virtual unenhanced images and true unenhanced images acquired with dual-energy CT (DECT). We enrolled 112 patients with right upper quadrant pain and clinically suspected acute cholecystitis or gallstone who underwent DECT--including unenhanced, arterial, and portal phases. Eighty-three gallstones with composition proven by semiquantitative Fourier transform infrared spectroscopy from 45 patients who had undergone cholecystectomy (40 cholesterol gallstones from 21 patients, 43 calcium gallstones from 24 patients) were included. CT images were retrospectively evaluated for stone size, contrast-to-noise ratio (CNR) of gallstone to bile, and visibility and density of gallstones for each image set. The visibility of each type of stone was compared with a paired t test. Both cholesterol and calcium stones measured smaller on virtual unenhanced images than on true unenhanced images, yielding a lower sensitivity of virtual unenhanced images for detecting small gallstones. Mean CNR of cholesterol stones was 2.45 ± 1.32 versus 1.67 ± 1.55 (p gallstones, but true unenhanced images allow better visualization of calcium and small gallstones.

  1. CT colonography atlas. For the practicing radiologist

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele; Faggioni, Lorenzo; Bartolozzi, Carlo (eds.) [Pisa Univ. (Italy). Dept. of Diagnostic and Interventional Radiology

    2013-11-01

    Easy-to-use atlas comprising a collection of representative common and unusual virtual colonoscopy (CTC) cases that are likely to be encountered during clinical practice. Reflects the important recent advances in image acquisition, patient preparation, and image processing. An invaluable tool both for radiologists performing CTC and for clinicians who need to review the CTC examinations of their patients. This easy-to-use atlas comprises a collection of representative common and unusual virtual colonoscopy (CT colonography, CTC) cases that physicians and radiologists may expect to encounter during their clinical practice. The atlas reflects the important recent advances in image acquisition, patient preparation, and image processing and is thus completely up-to-date. Each case is presented with the native CT images, integrated images obtained by 3D image processing, and colonoscopic correlation. Topics covered include normal appearances, anatomical variants, pitfalls, diverticula, lipomas, inflammatory bowel disease, polyps, flat lesions, cancers, and the postsurgical colon. By presenting the main features of anatomy and pathology, this atlas will serve as an invaluable tool both for radiologists performing CTC and for clinicians who need to review the CTC examinations of their patients.

  2. Techniques for virtual lung nodule insertion: volumetric and morphometric comparison of projection-based and image-based methods for quantitative CT.

    Science.gov (United States)

    Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Sedlmair, Martin; Roy Choudhury, Kingshuk; Pezeshk, Aria; Sahiner, Berkman; Samei, Ehsan

    2017-08-22

    Virtual nodule insertion paves the way towards the development of standardized databases of hybrid CT images with known lesions. The purpose of this study was to assess three methods (an established and two newly developed techniques) for inserting virtual lung nodules into CT images. Assessment was done by comparing virtual nodule volume and shape to the CT-derived volume and shape of synthetic nodules. 24 synthetic nodules (three sizes, four morphologies, two repeats) were physically inserted into the lung cavity of an anthropomorphic chest phantom (KYOTO KAGAKU). The phantom was imaged with and without nodules on a commercial CT scanner (SOMATOM Definition Flash, Siemens) using a standard thoracic CT protocol at two dose levels (1.4 and 22 mGy CTDIvol). Raw projection data were saved and reconstructed with filtered back-projection and sinogram affirmed iterative reconstruction (SAFIRE, strength 5) at 0.6 mm slice thickness. Corresponding 3D idealized, virtual nodule models were co-registered with the CT images to determine each nodule's location and orientation. Virtual nodules were voxelized, partial volume corrected, and inserted into nodule-free CT data (accounting for system imaging physics) using two methods: projection-based Technique A, and image-based Technique B. Also a third Technique C based on cropping a region of interest from the acquired image of the real nodule and blending it into the nodule-free image was tested. Nodule volumes were measured using a commercial segmentation tool (iNtuition, TeraRecon, Inc.) and deformation was assessed using the Hausdorff distance. Nodule volumes and deformations were compared between the idealized, CT-derived and virtual nodules using a linear mixed effects regression model which utilized the mean, standard deviation, and coefficient of variation ([Formula: see text], [Formula: see text] and [Formula: see text] of the regional Hausdorff distance. Overall, there was a close concordance between the volumes of

  3. Techniques for virtual lung nodule insertion: volumetric and morphometric comparison of projection-based and image-based methods for quantitative CT

    Science.gov (United States)

    Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Sedlmair, Martin; Choudhury, Kingshuk Roy; Pezeshk, Aria; Sahiner, Berkman; Samei, Ehsan

    2017-09-01

    Virtual nodule insertion paves the way towards the development of standardized databases of hybrid CT images with known lesions. The purpose of this study was to assess three methods (an established and two newly developed techniques) for inserting virtual lung nodules into CT images. Assessment was done by comparing virtual nodule volume and shape to the CT-derived volume and shape of synthetic nodules. 24 synthetic nodules (three sizes, four morphologies, two repeats) were physically inserted into the lung cavity of an anthropomorphic chest phantom (KYOTO KAGAKU). The phantom was imaged with and without nodules on a commercial CT scanner (SOMATOM Definition Flash, Siemens) using a standard thoracic CT protocol at two dose levels (1.4 and 22 mGy CTDIvol). Raw projection data were saved and reconstructed with filtered back-projection and sinogram affirmed iterative reconstruction (SAFIRE, strength 5) at 0.6 mm slice thickness. Corresponding 3D idealized, virtual nodule models were co-registered with the CT images to determine each nodule’s location and orientation. Virtual nodules were voxelized, partial volume corrected, and inserted into nodule-free CT data (accounting for system imaging physics) using two methods: projection-based Technique A, and image-based Technique B. Also a third Technique C based on cropping a region of interest from the acquired image of the real nodule and blending it into the nodule-free image was tested. Nodule volumes were measured using a commercial segmentation tool (iNtuition, TeraRecon, Inc.) and deformation was assessed using the Hausdorff distance. Nodule volumes and deformations were compared between the idealized, CT-derived and virtual nodules using a linear mixed effects regression model which utilized the mean, standard deviation, and coefficient of variation (Mea{{n}RHD} , ST{{D}RHD} and C{{V}RHD}{) }~ of the regional Hausdorff distance. Overall, there was a close concordance between the volumes of the CT-derived and

  4. Single minimum incision endoscopic radical nephrectomy for renal tumors with preoperative virtual navigation using 3D-CT volume-rendering

    Directory of Open Access Journals (Sweden)

    Shioyama Yasukazu

    2010-04-01

    Full Text Available Abstract Background Single minimum incision endoscopic surgery (MIES involves the use of a flexible high-definition laparoscope to facilitate open surgery. We reviewed our method of radical nephrectomy for renal tumors, which is single MIES combined with preoperative virtual surgery employing three-dimensional CT images reconstructed by the volume rendering method (3D-CT images in order to safely and appropriately approach the renal hilar vessels. We also assessed the usefulness of 3D-CT images. Methods Radical nephrectomy was done by single MIES via the translumbar approach in 80 consecutive patients. We performed the initial 20 MIES nephrectomies without preoperative 3D-CT images and the subsequent 60 MIES nephrectomies with preoperative 3D-CT images for evaluation of the renal hilar vessels and the relation of each tumor to the surrounding structures. On the basis of the 3D information, preoperative virtual surgery was performed with a computer. Results Single MIES nephrectomy was successful in all patients. In the 60 patients who underwent 3D-CT, the number of renal arteries and veins corresponded exactly with the preoperative 3D-CT data (100% sensitivity and 100% specificity. These 60 nephrectomies were completed with a shorter operating time and smaller blood loss than the initial 20 nephrectomies. Conclusions Single MIES radical nephrectomy combined with 3D-CT and virtual surgery achieved a shorter operating time and less blood loss, possibly due to safer and easier handling of the renal hilar vessels.

  5. Virtual monochromatic imaging in dual-source and dual-energy CT for visualization of acute ischemic stroke

    CERN Document Server

    Hara, Hidetake; Matsuzawa, Hiroki; Inoue, Toshiyuki; Abe, Shinji; Satoh, Hitoshi; Nakajima, Yasuo

    2015-01-01

    We have recently developed a phantom that simulates acute ischemic stroke. We attempted to visualize acute-stage cerebral infarction by applying virtual monochromatic images to this phantom using dual-energy CT (DECT). Virtual monochromatic images were created using DECT from 40 to 100 keV at every 10 keV and from 60 to 80 keV at every 1 keV, under three energy conditions of tube voltages with thin (Sn) filters. Calculation of the CNR values allowed us to evaluate the visualization of acute-stage cerebral infarction. The CNR value of a virtual monochromatic image was the highest at 68 keV under 80 kV / Sn 140 kV, at 72 keV under 100 kV / Sn 140 kV, and at 67 keV under 140 kV / 80 kV. The CNR values of virtual monochromatic images between 65 and 75 keV were significantly higher than those obtained for all other created energy images. Therefore, optimal conditions for visualizing acute ischemic stroke were achievable.

  6. Colonoscopy and computerised tomography scan are not sufficient to localise right sided colonic lesions accurately.

    LENUS (Irish Health Repository)

    Solon, Jacqueline Gemma

    2009-11-23

    : Aim: accurate pre-operative localisation of colonic lesions is critical especially in laparoscopic colectomy where tactile localisation is absent particularly in screen-detected tumours. The study aimed to evaluate the accuracy of colonoscopy and double-contrast computerised tomography (CT) to localise lesions treated by right hemicolectomy. Method: a retrospective chart review was performed of patients treated by right hemicolectomy under the colorectal service between July 2003 and October 2006. Pre-operative tumour location determined by CT scan and colonoscopy were compared with the intra-operative and histopathologic findings. Results: of 101 patients, 73 (73%) were for adenoma or cancer, with a final diagnosis of adenocarcinoma in 59 (59%). Pre-operative localisation was inaccurate in 29% of lesions using both CT and colonoscopy. In the transverse colon colonoscopy alone was only 37.5% accurate, increasing to 62.5% when information from the CT scan was added. Conclusion: pre-operative localisation of right-sided colon cancers using colonoscopy and CT scanning is unreliable in at least 29% of cases. Inaccurate localisation of transverse colon tumours risks inadequate lymphadenectomy with an adverse cancer outcome. Pre-operative abdominal CT scan improves accuracy but endoscopic tattoo localisation should be employed routinely especially in patients undergoing laparoscopic resection.

  7. The impact of fair colonoscopy preparation on colonoscopy use and adenoma miss rates in patients undergoing outpatient colonoscopy

    Science.gov (United States)

    Menees, Stacy B.; Kim, H. Myra; Elliott, Eric E.; Mickevicius, Jennifer L.; Graustein, Brittany B.; Schoenfeld, Philip S.

    2013-01-01

    Background The impact of fair bowel preparation on endoscopists’ recommendations and adenoma miss rates in average-risk patients undergoing colonoscopy is unknown. Objective To assess the impact of fair bowel preparation on endoscopists’ interval colonoscopy recommendations and miss rates in colonoscopies performed within 3 years of the index colonoscopy in average-risk patients undergoing colorectal cancer screening. Design Retrospective chart review. Setting Tertiary-care center. Patients Average-risk patients undergoing index colonoscopy for colorectal cancer screening between 2004 and 2006. Intervention Colonoscopy. Main Outcome Measurements Endoscopists’ interval recommendations, adenoma miss rates. Results A total of 16,251 colonoscopy records were reviewed over a 2-year period. Of these cases, 1943 colonoscopies were performed for the sole indication of average risk or screening. Of these, fair bowel preparation was reported in 619 patients (31.9%). A repeat colonoscopy within 5 years was recommended in 70.4% of patients. The follow-up colonoscopy compliance rate within 3 years was 55.9%. Adenoma detection rates at index and follow-up colonoscopy were 20.5% and 28.2%, respectively. Of the 39 patients with follow-up colonoscopy within 3 years, the overall adenoma miss rate was 28%. Of the patients with an adenoma identified on follow-up colonoscopy, 13.6% had normal colonoscopy results on index examination. Limitations Retrospective design. Conclusion Fair bowel preparation led to a deviation from national guidelines with early repeat colonoscopy follow-up recommendations in nearly 60% of average-risk patients with normal colonoscopy results. In patients who returned for repeat colonoscopy within 3 years, the overall adenoma miss rate was 28%. Further guidelines on timing for repeat colonoscopy for fair bowel preparation are needed. PMID:23642491

  8. A virtual clinical trial using projection-based nodule insertion to determine radiologist reader performance in lung cancer screening CT

    Science.gov (United States)

    Yu, Lifeng; Hu, Qiyuan; Koo, Chi Wan; Takahashi, Edwin A.; Levin, David L.; Johnson, Tucker F.; Hora, Megan J.; Dirks, Shane; Chen, Baiyu; McMillan, Kyle; Leng, Shuai; Fletcher, J. G.; McCollough, Cynthia H.

    2017-03-01

    Task-based image quality assessment using model observers is promising to provide an efficient, quantitative, and objective approach to CT dose optimization. Before this approach can be reliably used in practice, its correlation with radiologist performance for the same clinical task needs to be established. Determining human observer performance for a well-defined clinical task, however, has always been a challenge due to the tremendous amount of efforts needed to collect a large number of positive cases. To overcome this challenge, we developed an accurate projection-based insertion technique. In this study, we present a virtual clinical trial using this tool and a low-dose simulation tool to determine radiologist performance on lung-nodule detection as a function of radiation dose, nodule type, nodule size, and reconstruction methods. The lesion insertion and low-dose simulation tools together were demonstrated to provide flexibility to generate realistically-appearing clinical cases under well-defined conditions. The reader performance data obtained in this virtual clinical trial can be used as the basis to develop model observers for lung nodule detection, as well as for dose and protocol optimization in lung cancer screening CT.

  9. The use of a new 3D splint and double CT scan procedure to obtain an accurate anatomic virtual augmented model of the skull.

    Science.gov (United States)

    Swennen, G R J; Barth, E-L; Eulzer, C; Schutyser, F

    2007-02-01

    Three-dimensional (3D) virtual planning of orthognathic surgery requires detailed visualization of the interocclusal relationship. The purpose of this study was to introduce the modification of the double computed tomography (CT) scan procedure using a newly designed 3D splint in order to obtain a detailed anatomic 3D virtual augmented model of the skull. A total of 10 dry adult human cadaver skulls were used to evaluate the accuracy of the automatic rigid registration method for fusion of both CT datasets (Maxilim, version 1.3.0). The overall mean registration error was 0.1355+/-0.0323 mm (range 0.0760-0.1782 mm). Analysis of variance showed a registration method error of 0.0564 mm (P 3D splint with the double CT scan procedure allowed accurate registration and the set-up of an accurate anatomic 3D virtual augmented model of the skull with detailed dental surface.

  10. COLONOSCOPY AND CARCINOEMBRYONIC ANTIGEN VARIATIONS

    Directory of Open Access Journals (Sweden)

    Rita G SOUSA

    2014-03-01

    Full Text Available Context Colonoscopy is essential for synchronous and metachronous cancer detection. Carcinoembryonic antigen is a colorectal cancer tumor marker, important as a follow-up tool in patients with previous colorectal cancer. False-positive carcinoembryonic antigen elevation results in multiples exams and in patient anxiety. In literature, there is reference to transient carcinoembryonic antigen increase with colonoscopy. Objective To evaluate the influence of bowel preparation and colonoscopy in carcinoembryonic antigen blood levels. Methods We prospectively studied subjects that underwent routine colonoscopy in our institution. Blood samples were collected (1 before bowel cleaning, (2 before colonoscopy and (3 immediately after colonoscopy. Blood carcinoembryonic antigen levels were determined by “Sandwich” immunoassay. The statistical methods used were the paired t-test and ANOVA. Results Thirty-seven patients (22M/15F were included; age range 28-84 (mean 56 years. Mean carcinoembryonic antigen values were 1.9, 2 and 1.8 for (1, (2 and (3, respectively. An increase in value (2 compared with (1 was observed in 20/37 patients (P = 0.018, mainly in younger patients and in patients requiring more endoluminal interventions. In 29/37 patients, the CEA value decreased from (2 to (3 (P = 1.3x10-7. Conclusions A trend for carcinoembryonic antigen increase after bowel cleaning was observed, especially in younger patients and in patients with more endoluminal interventions, but without clinical meaning.

  11. Splenic rupture following routine colonoscopy.

    Science.gov (United States)

    Rasul, Tabraze; Leung, Edmund; McArdle, Kirsten; Pathak, Rajiv; Dalmia, Sanjay

    2010-10-01

    Splenic rupture is a life-threatening condition characterized by internal hemorrhage, often difficult to diagnose. Colonoscopy is a gold standard routine diagnostic test to investigate patients with gastrointestinal symptoms as well as to those on the screening program for colorectal cancer. Splenic injury is seldomly discussed during consent for colonoscopy, as opposed to colonic perforation, as its prevalence accounts for less than 0.1%. A 66-year-old Caucasian woman with no history of collagen disorder was electively admitted for routine colonoscopy for surveillance of adenoma. She was admitted following the procedure for re-dosing of warfarin, which was stopped prior to the colonoscopy. The patient was found collapsed on the ward the following day with clinical shock and anemia. Computed tomography demonstrated grade 4 splenic rupture. Immediate blood transfusion and splenectomy was required. Splenic rupture following routine colonoscopy is extremely rare. Awareness of it on this occasion saved the patient's life. Despite it being a rare association, the seriousness warrants inclusion in all information leaflets concerning colonoscopy and during its consent.

  12. Assessment of 70-keV virtual monoenergetic spectral images in abdominal CT imaging: A comparison study to conventional polychromatic 120-kVp images.

    Science.gov (United States)

    Rassouli, Negin; Chalian, Hamid; Rajiah, Prabhakar; Dhanantwari, Amar; Landeras, Luis

    2017-04-18

    To evaluate the image quality of 70-keV virtual monoenergetic (monoE) abdominal CT images compared to 120-kVp polychromatic images generated from a spectral detector CT (SDCT) scanner. This prospective study included generation of a 120-kVp polychromatic dataset and a 70-keV virtual monoE dataset after a single contrast-enhanced CT acquisition on a SDCT scanner (Philips Healthcare) during portal venous phase. The attenuation values (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in the liver, spleen, pancreas, kidney, aorta, portal vein, and muscle. The subjective image quality including noise, soft tissue contrast, sharpness, and overall image quality were graded on a 5-point Likert scale by two radiologists independently (1-worst image quality, 5-best image quality). Statistical analysis was performed using paired sample t test and Fleiss's Kappa. Fifty-five patients (54.3 ± 16.8 y/o; 28 M, 27 F) were recruited. The noise of target organs was significantly lower in virtual monoE images in comparison to polychromatic images (p virtual monoE images (p virtual monoE images was significantly better (p virtual monoE images, respectively. The inter-reader agreement for overall image quality was good (Kappa were 0.767 and 0.762 for polychromatic and virtual monoE images, respectively). In abdominal imaging, 70-keV virtual monoE CT images demonstrated significantly better noise, SNR, CNR, and subjective score compared to conventional 120-kVp polychromatic images.

  13. Cadaver-specific CT scans visualized at the dissection table combined with virtual dissection tables improve learning performance in general gross anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Paech, Daniel [German Cancer Research Center, Department of Radiology, Heidelberg (Germany); Heidelberg University, Institute of Anatomy and Cell Biology, Heidelberg (Germany); Giesel, Frederik L. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); Unterhinninghofen, Roland [Institute of Anthropomatics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Schlemmer, Heinz-Peter [German Cancer Research Center, Department of Radiology, Heidelberg (Germany); Kuner, Thomas; Doll, Sara [Heidelberg University, Institute of Anatomy and Cell Biology, Heidelberg (Germany)

    2017-05-15

    The purpose of this study was to quantify the benefit of the incorporation of radiologic anatomy (RA), in terms of student training in RA seminars, cadaver CT scans and life-size virtual dissection tables on the learning success in general anatomy. Three groups of a total of 238 students were compared in a multiple choice general anatomy exam during first-year gross anatomy: (1) a group (year 2015, n{sub 1} = 50) that received training in radiologic image interpretation (RA seminar) and additional access to cadaver CT scans (CT + seminar group); (2) a group (2011, n{sub 2} = 90) that was trained in the RA seminar only (RA seminar group); (3) a group (2011, n{sub 3} = 98) without any radiologic image interpretation training (conventional anatomy group). Furthermore, the students' perception of the new curriculum was assessed qualitatively through a survey. The average test score of the CT + seminar group (21.8 ± 5.0) was significantly higher when compared to both the RA seminar group (18.3 ± 5.0) and the conventional anatomy group (17.1 ± 4.7) (p < 0.001). The incorporation of cadaver CT scans and life-size virtual dissection tables significantly improved the performance of medical students in general gross anatomy. Medical imaging and virtual dissection should therefore be considered to be part of the standard curriculum of gross anatomy. circle Students provided with cadaver CT scans achieved 27 % higher scores in anatomy. (orig.)

  14. Virtual animation of victim-specific 3D models obtained from CT scans for forensic reconstructions: Living and dead subjects.

    Science.gov (United States)

    Villa, C; Olsen, K B; Hansen, S H

    2017-09-01

    Post-mortem CT scanning (PMCT) has been introduced at several forensic medical institutions many years ago and has proved to be a useful tool. 3D models of bones, skin, internal organs and bullet paths can rapidly be generated using post-processing software. These 3D models reflect the individual physiognomics and can be used to create whole-body 3D virtual animations. In such way, virtual reconstructions of the probable ante-mortem postures of victims can be constructed and contribute to understand the sequence of events. This procedure is demonstrated in two victims of gunshot injuries. Case #1 was a man showing three perforating gunshot wounds, who died due to the injuries of the incident. Whole-body PMCT was performed and 3D reconstructions of bones, relevant internal organs and bullet paths were generated. Using 3ds Max software and a human anatomy 3D model, a virtual animated body was built and probable ante-mortem postures visualized. Case #2 was a man presenting three perforating gunshot wounds, who survived the incident: one in the left arm and two in the thorax. Only CT scans of the thorax, abdomen and the injured arm were provided by the hospital. Therefore, a whole-body 3D model reflecting the anatomical proportions of the patient was made combining the actual bones of the victim with those obtained from the human anatomy 3D model. The resulted 3D model was used for the animation process. Several probable postures were also visualized in this case. It has be shown that in Case #1 the lesions and the bullet path were not consistent with an upright standing position; instead, the victim was slightly bent forward, i.e. he was sitting or running when he was shot. In Case #2, one of the bullets could have passed through the arm and continued into the thorax. In conclusion, specialized 3D modelling and animation techniques allow for the reconstruction of ante-mortem postures based on both PMCT and clinical CT. Copyright © 2017 Elsevier B.V. All rights

  15. 仿真结肠镜运用系统反馈独立训练与教师指导训练的比较研究%The comparative study on colonoscopy skills after virtual reality simulator training by independent and proctored methods

    Institute of Scientific and Technical Information of China (English)

    白杨; 张亚历; 姜泊; 智发朝; 杜庆峰; 刘思德; 张强; 潘德寿; 杜许峰; 蔡建群; 肖冰

    2011-01-01

    目的 本研究拟开展仿真内镜不同训练模式对结肠镜技能建立的作用研究,以期发现最优化的训练模式.方法 将学员分为2组,A组采用自学法,B组教师指导法.训练完成后根据成绩判断哪种训练方法最适合结肠镜受训学员.结果 两组总体评分无显著性差异,各环节比较包括安全性、准确度、残气量、肠袢形成及操作时间方面均无显著性差异.结论 本研究表明应推荐自学法为仿真结肠镜的训练方法.%Objective To investigate the role of the different virtual reality simulator training methods during the forming of the colonoscopy skills. Methods The novice colonoscopists were divided into two groups. Group A accepted the independent training; Group B accepted the proctored training. After finishing the training, scores of two different groups were compared. Results There had no significant difference in terms of safety, accuracy, overinsuffiation, intestinal loop forming and speed between two groups. Conclusion The independent method should be recommended for virtual reality simulator training of colonoscopy skills.

  16. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... for Clinical Research and Education, underscores the lifesaving importance of colorectal screening by colonoscopy. The video instills confidence in patients about the effectiveness, safety and importance of colonoscopy. Featuring the experience of a female ...

  17. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... for Clinical Research and Education, underscores the lifesaving importance of colorectal screening by colonoscopy. The video instills confidence in patients about the effectiveness, safety and importance of colonoscopy. Featuring the experience of a female ...

  18. CT colonography as routine method; CT-Kolonographie in der taeglichen Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, G.; Gschwendtner, M. [Krankenhaus Elisabethinen Linz, Institut fuer Diagnostische und Interventionelle Radiologie, Linz (Austria); Mang, T. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2012-06-15

    Colorectal cancer is a major public health challenge in Austria and Germany. As the participation in dedicated colonoscopy screening programs is rather low, the question of alternative methods is raised again and computed tomography (CT) colonography seems to be a gentle alternative with a very high patient acceptance. In recent years CT colonography (CTC) has been established besides conventional colonoscopy as a radiological method for the investigation of the entire colon. From axial two-dimensional images three-dimensional images can be generated, allowing a virtual flight through the colon which is why this technique is also known as virtual colonoscopy. The technique of CTC has been improved continuously during recent years. On the one hand the steady decrease in the layer thickness (currently {<=} 1 mm) has improved the resolution of volume data sets and on the other hand there has been significant progress in postprocessing. Numerous studies have recently shown that the significance of CTC in the detection of advanced adenomas is similar to conventional colonoscopy. Meanwhile CT colonography is now a routine investigation method established in both symptomatic and asymptomatic patients (screening). Study data now clearly show that CTC, as an alternative to conventional colonoscopy, is a powerful method for investigation of colorectal cancer. To achieve good results adequate preparation including fecal tagging, standardized technical procedures during the investigation and expertise in both 2D and 3D reading are essential. (orig.) [German] Das kolorektale Karzinom stellt sowohl in Oesterreich wie auch in Deutschland eine grosse gesundheitspolitische Herausforderung dar. Da die Teilnahme seitens der Betroffenen an Koloskopievorsorgeprogrammen eher gering ausfaellt, wird immer wieder die Frage nach alternativen Untersuchungsmethoden aufgeworfen. Hier scheint die CT-Kolonographie eine schonende Alternative darzustellen, welche eine hohe Patientenakzeptanz

  19. Virtual teeth: a 3D method for editing and visualizing small structures in CT scans

    DEFF Research Database (Denmark)

    Bro-Nielsen, Morten; Larsen, Per; Kreiborg, Sven

    1996-01-01

    The paper presents an interactive method for segmentation and visualization of small structures in CT scans. A combination of isosurface generation, spatial region growing and interactive graphics tools are used to extract small structures interactively. A practical example of segmentation of the...

  20. The use of a new 3D splint and double CT scan procedure to obtain an accurate anatomic virtual augmented model of the skull.

    NARCIS (Netherlands)

    Swennen, G.R.; Barth, E.L.; Eulzer, C.; Schutyser, F.A.C.

    2007-01-01

    Three-dimensional (3D) virtual planning of orthognathic surgery requires detailed visualization of the interocclusal relationship. The purpose of this study was to introduce the modification of the double computed tomography (CT) scan procedure using a newly designed 3D splint in order to obtain a d

  1. Virtual non-contrast dual-energy CT compared to single-energy CT of the urinary tract: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, Margareta; Liden, Mats; Geijer, Haakan; Andersson, Torbjoern [Dept. of Radiology, Oerebro Univ. Hospital, Oerebro Univ., Oerebro (Sweden)], E-mail: margareta.lundin@orebroll.se; Magnuson, Anders [Clinical Epidemiology and Biostatistic Unit, Oerebro Univ. Hospital, Oerebro (Sweden); Mohammed, Ahmed Abdulilah [Dept. of Radiology, Linkoeping Univ. Hospital, Linkoeping (Sweden); Persson, Anders [CMIV Center for Medical Image Science and Visualization, Linkoeping (Sweden)

    2012-07-15

    Background. Dual-energy computed tomography (DECT) has been shown to be useful for subtracting bone or calcium in CT angiography and gives an opportunity to produce a virtual non-contrast-enhanced (VNC) image from a series where contrast agents have been given intravenously. High noise levels and low resolution have previously limited the diagnostic value of the VNC images created with the first generation of DECT. With the recent introduction of a second generation of DECT, there is a possibility of obtaining VNC images with better image quality at hopefully lower radiation dose compared to the previous generation. Purpose. To compare the image quality of the single-energy series to a VNC series obtained with a two generations of DECT scanners. CT of the urinary tract was used as a model. Material and Methods. Thirty patients referred for evaluation of hematuria were examined with an older system (Somatom Definition) and another 30 patients with a new generation (Somatom Definition Flash). One single-energy series was obtained before and one dual-energy series after administration of intravenous contrast media. We created a VNC series from the contrast-enhanced images. Images were assessed concerning image quality with a visual grading scale evaluation of the VNC series with the single-energy series as gold standard. Results. The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, OR 11.5-67.3 for the Definition and OR 2.1-2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than Definition. Conclusion. Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images. However, the difference is smaller with the new compared to the older system.

  2. TU-EF-204-12: Quantitative Evaluation of Spectral Detector CT Using Virtual Monochromatic Images: Initial Results

    Energy Technology Data Exchange (ETDEWEB)

    Duan, X; Guild, J [UT Southwestern Medical Center, Dallas, TX (United States); Arbique, G; Anderson, J [UT Southwestern Medical Ctr at Dallas, Dallas, TX (United States); Dhanantwari, A [Philips Healthcare, Highland Heights, OH (United States); Yagil, Y [Philips Medical Systems, Haifa (Israel)

    2015-06-15

    Purpose To evaluate the image quality and spectral information of a spectral detector CT (SDCT) scanner using virtual monochromatic (VM) energy images. Methods The SDCT scanner (Philips Healthcare) was equipped with a dual-layer detector and spectral iterative reconstruction (IR), which generates conventional 80–140 kV polychromatic energy (PE) CT images using both detector layers, PE images from the low-energy (upper) and high-energy (lower) detector layers and VM images. A solid water phantom with iodine (2.0–20.0 mg I/ml) and calcium (50.0–600.0 mg Ca/ml) rod inserts was used to evaluate effective energy estimate (EEE) and iodine contrast to noise ratio (CNR). The EEE corresponding to an insert CT number in a PE image was calculated from a CT number fit to the VM image set. Since PE image is prone to beam-hardening artifact EEE may underestimate the actual energy separation from two layers of the detector. A 30-cm-diameter water phantom was used to evaluate noise power spectrum (NPS). The phantoms were scanned at 120 and 140 kV with the same CTDIvol. Results The CT number difference for contrast inserts in VM images (50–150 keV) was 1.3±6% between 120 and 140 kV scans. The difference of EEE calculated from low- and high-energy detector images was 11.5 and 16.7 keV for 120 and 140 kV scans, respectively. The differences calculated from 140 and 100 kV conventional PE images were 12.8, and 20.1 keV from 140 and 80 kV conventional PE images. The iodine CNR increased monotonically with decreased keV. Compared to conventional PE images, the peak of NPS curves from VM images were shifted to lower frequency. Conclusion The EEE results indicates that SDCT at 120 and 140 kV may have energy separation comparable to 100/140 kV and 80/140 kV dual-kV imaging. The effects of IR on CNR and NPS require further investigation for SDCT. Author YY and AD are Philips Healthcare employees.

  3. Coronary CT Angiography in Coronary Artery Disease: Correlation between Virtual Intravascular Endoscopic Appearances and Left Bifurcation Angulation and Coronary Plaques

    Directory of Open Access Journals (Sweden)

    Zhonghua Sun

    2013-01-01

    Full Text Available The aim of this study is to investigate the relationship between intraluminal appearances of coronary plaques and left coronary bifurcation angle and plaque components using coronary CT virtual intravascular endoscopy (VIE. Fifty patients suspected of coronary artery disease undergoing coronary CT angiography were included in the study. The left bifurcation angle in patients with diseased left coronary artery which was measured as 94.3° ± 16.5 is significantly larger than that in patients with normal left coronary artery, which was measured as 76.5° ± 15.9 (P<0.001. Irregular VIE appearances were found in 10 out of 11 patients with mixed plaques in the left anterior descending (LAD and left circumflex (LCx, while, in 29 patients with calcified plaques in the LAD and LCx, irregular VIE appearances were only noticed in 5 patients. Using 80° as a cut-off value to determine coronary artery disease, smooth VIE appearances were found in 95% of patients (18/19 with left bifurcation angle of less than 80°, while irregular VIE appearances were observed in nearly 50% of patients (15/31 with left bifurcation angle of more than 80°. This preliminary study shows that VIE appearances of the coronary lumen are directly related to the types of plaques.

  4. Virtual 3-D {sup 18}F-FDG PET/CT panendoscopy for assessment of the upper airways of head and neck cancer patients: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian; Heusner, Till A. [University Duesseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Duesseldorf (Germany); University Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Treffert, Jon [Siemens Health Care, Molecular Imaging, Knoxville, TN (United States); Lehnerdt, Goetz; Mattheis, Stefan [University Duisburg-Essen, Medical Faculty, Department of Otorhinolaryngology, Essen (Germany); Geiger, Bernhard [Siemens Corporate Research Inc., Princeton, NJ (United States); Bockisch, Andreas [University Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Forsting, Michael [University Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Antoch, Gerald [University Duesseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Duesseldorf (Germany)

    2012-09-15

    The aim of this study was to evaluate whether a virtual 3-D {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT panendoscopy is feasible and can be used for noninvasive imaging of the upper airways and pharyngeal/laryngeal tumours. From {sup 18}F-FDG PET/CT data sets of 40 patients (29 men, 11 women; age 61 {+-} 9 years) with pharyngeal or laryngeal malignancies virtual 3-D {sup 18}F-FDG PET/CT panendoscopies were reconstructed and the image processing time was measured. The feasibility of assessing the oral cavity, nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, aryepiglottic folds, piriform sinus, postcricoid space, glottis, subglottis, trachea, bronchi and oesophagus and of detecting primary tumours was tested. Results of fibre-optic bronchoscopy and histology served as the reference standard. The nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, subglottis and the tracheobronchial tree were accessible in all 40, and the aryepiglottic folds, posterior hypopharyngeal wall, postcricoid space, piriform sinus, glottis, oral cavity and oesophagus in 37, 37, 37, 37, 33, 16 and 0 patients, respectively. In all 12 patients with restricted fibre-optic evaluation due to being primarily intubated, the subglottis was accessible via virtual panendoscopy. The primary tumour was depicted in 36 of 40 patients (90 %). The mean processing time for virtual {sup 18}F-FDG PET/CT panendoscopies was 145 {+-} 98 s. Virtual {sup 18}F-FDG PET/CT panendoscopy of the upper airways is technically feasible and can detect pharyngeal and laryngeal malignancies. This new tool can aid in the complete evaluation of the subglottic space in intubated patients and may be used for planning optical panendoscopies, biopsies and surgery in the future. (orig.)

  5. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment

    Science.gov (United States)

    Miksys, N.; Xu, C.; Beaulieu, L.; Thomson, R. M.

    2015-08-01

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  6. Massaal rectaal bloedverlies na colonoscopie

    NARCIS (Netherlands)

    Kampschreur, M T Milou; Kats-Ugurlu, Gursah; van Suylen, Robert Jan; De Schryver, Anneke M P

    2012-01-01

    A 70-year-old man presented with acute lower gastrointestinal bleeding. A colonoscopy performed one and a half months prior had revealed diverticulosis in the sigmoid colon; a small polyp located 10 cm from the anal margin had been removed at that time. The presenting patient was haemodynamically un

  7. SU-D-BRA-06: Dual-Energy Chest CT: The Effects of Virtual Monochromatic Reconstructions On Texture Analysis Features

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J; Duran, C; Stingo, F; Wei, W; Rao, A; Zhang, L; Court, L; Erasmus, J; Godoy, M [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To characterize the effect of virtual monochromatic reconstructions on several commonly used texture analysis features in DECT of the chest. Further, to assess the effect of monochromatic energy levels on the ability of these textural features to identify tissue types. Methods: 20 consecutive patients underwent chest CTs for evaluation of lung nodules using Siemens Somatom Definition Flash DECT. Virtual monochromatic images were constructed at 10keV intervals from 40–190keV. For each patient, an ROI delineated the lesion under investigation, and cylindrical ROI’s were placed within 5 different healthy tissues (blood, fat, muscle, lung, and liver). Several histogram- and Grey Level Cooccurrence Matrix (GLCM)-based texture features were then evaluated in each ROI at each energy level. As a means of validation, these feature values were then used in a random forest classifier to attempt to identify the tissue types present within each ROI. Their predictive accuracy at each energy level was recorded. Results: All textural features changed considerably with virtual monochromatic energy, particularly below 70keV. Most features exhibited a global minimum or maximum around 80keV, and while feature values changed with energy above this, patient ranking was generally unaffected. As expected, blood demonstrated the lowest inter-patient variability, for all features, while lung lesions (encompassing many different pathologies) exhibited the highest. The accuracy of these features in identifying tissues (76% accuracy) was highest at 80keV, but no clear relationship between energy and classification accuracy was found. Two common misclassifications (blood vs liver and muscle vs fat) accounted for the majority (24 of the 28) errors observed. Conclusion: All textural features were highly dependent on virtual monochromatic energy level, especially below 80keV, and were more stable above this energy. However, in a random forest model, these commonly used features were

  8. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction.

    Science.gov (United States)

    Xu, Jinyu; Deng, Benqiang; Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC 0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

  9. Evaluation of patient dose using a virtual CT scanner: Applications to 4DCT simulation and Kilovoltage cone-beam imaging

    Science.gov (United States)

    DeMarco, J. J.; McNitt-Gray, M. F.; Cagnon, C. H.; Angel, E.; Agazaryan, N.; Zankl, M.

    2008-02-01

    This work evaluates the effects of patient size on radiation dose from simulation imaging studies such as four-dimensional computed tomography (4DCT) and kilovoltage cone-beam computed tomography (kV-CBCT). 4DCT studies are scans that include temporal information, frequently incorporating highly over-sampled imaging series necessary for retrospective sorting as a function of respiratory phase. This type of imaging study can result in a significant dose increase to the patient due to the slower table speed as compared with a conventional axial or helical scan protocol. Kilovoltage cone-beam imaging is a relatively new imaging technique that requires an on-board kilovoltage x-ray tube and a flat-panel detector. Instead of porting individual reference fields, the kV tube and flat-panel detector are rotated about the patient producing a cone-beam CT data set (kV-CBCT). To perform these investigations, we used Monte Carlo simulation methods with detailed models of adult patients and virtual source models of multidetector computed tomography (MDCT) scanners. The GSF family of three-dimensional, voxelized patient models, were implemented as input files using the Monte Carlo code MCNPX. The adult patient models represent a range of patient sizes and have all radiosensitive organs previously identified and segmented. Simulated 4DCT scans of each voxelized patient model were performed using a multi-detector CT source model that includes scanner specific spectra, bow-tie filtration, and helical source path. Standard MCNPX tally functions were applied to each model to estimate absolute organ dose based upon an air-kerma normalization measurement for nominal scanner operating parameters.

  10. Expert and construct validity of the Simbionix GI Mentor II endoscopy simulator for colonoscopy

    NARCIS (Netherlands)

    Koch, A.D.; Buzink, S.N.; Heemskerk, J.; Botden, S.M.B.I.; Veenendaal, R; Jakimowicz, J.J.; Schoon, E.J.

    2007-01-01

    Objectives The main objectives of this study were to establish expert validity (a convincing realistic representation of colonoscopy according to experts) and construct validity (the ability to discriminate between different levels of expertise) of the Simbionix GI Mentor II virtual reality (VR) si

  11. Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

    2012-09-15

    Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

  12. Retrospective Evaluation of Colonoscopy Results

    Directory of Open Access Journals (Sweden)

    Yaşar M et al.

    2010-09-01

    Full Text Available Aim: The aim of this study is the retrospective evaluation of colonoscopy results between 2005 January- 2009 December in General Surgery Department of Düzce University.Materials and Methods: Admitted to our department with lower gastrointestinal symptoms, and colonoscopy is indicated 500 male and 538 female total 1038 patients were performed flexible colonoscopic examinations after bowel cleansing.Results: According to results of colonoscopic findings, 42.9% No pathology, 32.5% Hemorrhoids, 17.6% Anal fissures were detected.Conclusion: As a result of this study, half of patients admitted to our surgical clinic with lower gastrointestinal complaints have no pathology and in the other half of patients have various pathologies such as hemorrhoids and anal fissures.

  13. CT仿真输尿管膀胱镜成像的初步临床应用%CT Virtual Ureterocystoscopy: Preliminary Clinical Applications

    Institute of Scientific and Technical Information of China (English)

    杨秀军; 彭仁罗; 凌桂明; 文伟; 陈海曦; 陈元炯

    2001-01-01

    Objective To detect the techniques and clinical value of CT virtual endoscopy of urinary tracts. Methods Virtual endoscopy(VE) of urinary tracts was performed in 47 cases, using navigator software based on the source imaging data of excretory helical CT urography(CT-IVU) with the following scanning parameters:slice 5mm,pitch 2.0 or 1.0. Images were reconstructed at 2.5mm interval. Excretory scout was done in 41 cases.Six cases were underwent meanwhile ureterorenoscopy or cystoscopy. Results The technical success rate of CT-IVU and VE was 100% without any complication. The 3D display of Virtual ureterocystoscopy depicted endoscopelike the innerlumen anatomy and disorders of urinary tracts at any angle. The sensitivity of VE to bladder tumors more than 5 mm in diameter was 100%,with some tumor character. It added the diagnostic information to CT. It was difficult,however,for VE to detect the stones and to distinguish the normal uretal peristalses from stricture. Compared with ureterocystoscopy, the major limitation of CT virtual endoscopy was its inability to demonstrate the detail of lesions and mucosal surface of urinary tracts.The imaging quality of CT-IVU was better than that of X-IVU(P<0.05). Conclusion CT ureterocystoscopy provides endoscope-like display of urinary tracts and lesions.The diagnostic accuracy of tumors,but stones, is higher. CT-IVU is superior to X-IVU.%目的探讨CT仿真输尿管膀胱镜成像技术和价值。方法应用螺旋CT采集排泄期尿路断面影像47例,层厚5mm,螺距2.0或1.0,重建层厚2.5mm;将源影像送至工作站作内窥镜成像等后处理。6例同时作了膀胱镜或输尿管镜检查。结果 CT-IVU和VE技术成功率达100%,无并发症。VE内镜样显示了肾盏、肾盂、输尿管和膀胱内壁、内腔及其病变的三维结构,对5mm以上膀胱癌检出率达100%,较好地显示了肿瘤特征,增加了诊断信息。但VE无法显示尿路结石和区分输尿管真性

  14. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned...... colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy....

  15. Cadaver-specific CT scans visualized at the dissection table combined with virtual dissection tables improve learning performance in general gross anatomy.

    Science.gov (United States)

    Paech, Daniel; Giesel, Frederik L; Unterhinninghofen, Roland; Schlemmer, Heinz-Peter; Kuner, Thomas; Doll, Sara

    2017-05-01

    The purpose of this study was to quantify the benefit of the incorporation of radiologic anatomy (RA), in terms of student training in RA seminars, cadaver CT scans and life-size virtual dissection tables on the learning success in general anatomy. Three groups of a total of 238 students were compared in a multiple choice general anatomy exam during first-year gross anatomy: (1) a group (year 2015, n 1 = 50) that received training in radiologic image interpretation (RA seminar) and additional access to cadaver CT scans (CT + seminar group); (2) a group (2011, n 2 = 90) that was trained in the RA seminar only (RA seminar group); (3) a group (2011, n 3 = 98) without any radiologic image interpretation training (conventional anatomy group). Furthermore, the students' perception of the new curriculum was assessed qualitatively through a survey. The average test score of the CT + seminar group (21.8 ± 5.0) was significantly higher when compared to both the RA seminar group (18.3 ± 5.0) and the conventional anatomy group (17.1 ± 4.7) (p general gross anatomy. Medical imaging and virtual dissection should therefore be considered to be part of the standard curriculum of gross anatomy. • Students provided with cadaver CT scans achieved 27 % higher scores in anatomy. • Radiological education integrated into gross anatomy is highly appreciated by medical students. • Simultaneous physical and virtual dissection provide unique conditions to study anatomy.

  16. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... ACG Obesity Initiative IBS Awareness IBD Awareness Colorectal Cancer ... the lifesaving importance of colorectal screening by colonoscopy. The video instills confidence in patients ...

  17. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... ACG Obesity Initiative IBS Awareness IBD Awareness Colorectal ... the lifesaving importance of colorectal screening by colonoscopy. The video instills confidence in patients ...

  18. A Smartphone App for Improvement of Colonoscopy Preparation (ColoprAPP): Development and Feasibility Study.

    Science.gov (United States)

    Walter, Benjamin; Schmid, Roland; von Delius, Stefan

    2017-09-20

    Optimal bowel preparation is one of the major cornerstones for quality of colonoscopy. But poor bowel preparation still occurs in 10% to 25% of all patients. To optimize patient guidance, we developed a new smartphone app (ColoprAPP) for Android smartphones which guides and accompanies the patient starting 4 days before colonoscopy throughout the whole colonoscopy preparation procedure. The objective of this study was to assess the function of a newly developed smartphone app for supporting colonoscopy preparation. We carried out a prospective feasibility study including 25 patients undergoing outpatient colonoscopy at our hospital. As a control, we retrieved the data of 25 patients undergoing outpatient colonoscopy matching in age, sex, and indication for colonoscopy from our colonoscopy database. Patients were asked to download the smartphone app, ColoprAPP, in addition to being given the regular colonoscopy preparation leaflet. All colonoscopies were performed in the morning after using a split-dose preparation containing a polyethlene glycol-based purgative. The study was designed to test feasibility of the prototype, evaluate grade of bowel cleanliness (Boston bowel preparation scale [BBPS]), and assess patient satisfaction with the app. The smartphone app use was feasible in all patients. BBPS count as a marker for grade of bowel preparation was significantly higher in the smartphone app-supported group (mean 8.1 [SD 0.3] vs 7.1 [SD 0.4], P=.02). Left (mean 2.8 [SD 0.1] vs 2.4 [SD 0.11], P=.02) and transverse colon (mean 2.8 [SD 0.07] vs 2.4 [SD 0.11], Psmartphone app-supported group than in controls. Patient satisfaction with a smartphone app-supported colonoscopy preparation was high with an average numeric rating scale score for usefulness of 8.2 (visual analog scale 1-10). A novel developed smartphone app for reinforced education of bowel cleansing was feasible and led to high BBPS scores and patient satisfaction. ClinicalTrials.gov NCT02512328; https://clinicaltrials.gov/ct

  19. Performance of different categories of operators in simulated diagnostic colonoscopy.

    Science.gov (United States)

    Fasoli, Renato; Pertile, Riccardo; Seligman, Sonia; de Pretis, Giovanni

    2015-01-01

    The possible involvement, although limited to the diagnostic phase of the procedure, of nonmedical staff (particularly endoscopy nurses) in lower digestive endoscopy has recently been suggested. Computer-based simulators have demonstrated objective evaluation of technical skills in digestive endoscopy. The aim of this study was to evaluate basic colonoscopy skills of endoscopy nurses (naive operators), as compared with junior physician staff and senior endoscopists, through a virtual reality colonoscopy simulator. In this single-center, prospective, nonrandomized study, 3 groups of digestive endoscopy operators (endoscopy nurses, junior doctors [500 previous colonoscopies and >200/year]) completed six diagnostic cases generated by an endoscopic simulator (AccuTouch, Immersion Medical, Gaithersburg, MD). The performance parameters, collected by the simulator, were compared between groups. Five parameters have been considered for statistical analysis: time spent to reach the cecum; pain of any degree; severe/extreme pain; amount of insufflated air; percentage of visualized mucosa. Statistical analysis to compare the three groups has been performed by means of Wilcoxon test for two independent samples and by means of Kruskal-Wallis test for three independent samples (p < .05). Sixteen operators have been studied (six endoscopy nurses, five junior doctors, and five senior doctors); 96 colonoscopic procedures have been evaluated. Statistically significant differences between experts and naive operators were observed regarding time to reach the cecum and induction of severe/extreme pain, with both Kruskal-Wallis and Wilcoxon test (p < .05); all other comparisons did not reach statistical significance. Although, as expected, expert doctors exceeded both junior doctors and naive operators in some relevant quality parameters of simulated diagnostic colonoscopies, the results obtained by less expert performers--and particularly by nursing staff--appear satisfactory as in

  20. CT Virtual angioscopy of aortic arch%CT仿真血管内镜观察主动脉弓

    Institute of Scientific and Technical Information of China (English)

    李新平; 陈伟; 朱智明

    2011-01-01

    [ Objective ] To explore the clinical value of CT virtual angioscopy (CTVA) in the pre- and postpro-cedure evaluation of aortic arch related diseases. [Methods] 37 cases with thoracic disease underwent aortic CT angiography on a dual-source CT scanner. CTVA of aortic arch were performed with Fly-through software in all cas-? Es by using aortic CT angiographic source image data. [Results] 34 of 37 (92%) cases showed successful CTVA images, including aortic dissection (n =12), aneurysm (n =4), pseudoaneurysm (n =3), Takayasu arteritis (n =2),aortic coarctation (n =1), aneurysm combined with aortic dissection (n =1) and 11 patients following surgical or endovascu-lar procedures. CTVA of aortic arch could identify the ostia and its variations of supra-aortic vessels, estimate the localization of abnormalities with respect to supra-aortic vessels and display the stent grafts. [ Conclusions ] CTVA of aortic arch enables non-invasive visualization of the inner contours of the vasculature, and has certain instructive significance in the diagnostic classification, preprocedure planning and postprocedure evaluation for aortic arch related diseases.%目的 探讨CT仿真血管内镜(CTVA)在主动脉弓相关疾病术前和术后评价中的价值.方法 采用双源CT对37例胸主动脉疾病患者行主动脉CT成像检查,并将主动脉CT成像的源图像调至Fly-through软件中,对所有病例行主动脉弓CTVA观察.结果 92%(34/37)的病例获得了满意的CTVA图像,包括主动脉夹层12例、真性动脉瘤4例、假性动脉瘤3例、多发性大动脉炎2例、主动脉缩窄1例、真性动脉瘤合并夹层1例及11例术后随访病例.主动脉弓CTVA能明确弓上分支血管开口位置与变异、判断病变与弓上分支开口的空间关系以及显示支架型血管.结论 主动脉弓CTVA能无创观察血管腔内情况,对主动脉弓相关疾病的诊断分型、术前计划和术后评价具有一定的指导意义.

  1. Asymptomatic early acute appendicitis initiated and diagnosed during colonoscopy: A case report

    Institute of Scientific and Technical Information of China (English)

    Michelle Petro; Anil Minocha

    2005-01-01

    Colonoscopic diagnosis of asymptomatic early acute appendicitis is exceedingly rare. Although obstruction of the lumen due to various causes is believed to be the most common physiologic mechanism of acute appendicitis, all of the previously documented cases in the literature have only shown a patent appendiceal lumen with pus flowing into the cecum. We present the case of a patient undergoing colonoscopy for colorectal cancer evaluation with no abdominal symptoms. An obstructed, swollen appendix was seen. The process was probably initiated during the colonoscopy, documenting perhaps the earliest stage of acute appendicitis for the first time. Endoscopic, CT and microscopic documentation of the case is also presented.

  2. Endoleaks after endovascular aortic aneurysm repair: Improved detection with noise-optimized virtual monoenergetic dual-energy CT.

    Science.gov (United States)

    Martin, Simon S; Wichmann, Julian L; Weyer, Hendrik; Scholtz, Jan-Erik; Leithner, Doris; Spandorfer, Adam; Bodelle, Boris; Jacobi, Volkmar; Vogl, Thomas J; Albrecht, Moritz H

    2017-09-01

    To assess image quality and diagnostic performance of a noise-optimized algorithm to reconstruct virtual monoenergetic images (VMI+) for the detection of endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) using dual-energy CT angiography (DE-CTA). Seventy-five patients (42 men; 66.2±11.7years) underwent DE-CTA following EVAR. Arterial phase images were acquired in dual-energy mode for the reconstruction of standard linearly-blended M_0.5, VMI+ and traditional monoenergetic images (VMI) at 40-100keV in 10-keV intervals. Contrast-to-noise ratios (CNR) were calculated for the area of leakage in patients with endoleaks. Diagnostic accuracy for endoleak detection was evaluated by three blinded radiologists using the objectively best series for each reconstruction technique. Thirty-four out of 75 patients showed endoleaks. Quantitative image parameters were highest at 40-keV VMI+ (CNR, 21.3±11.1), compared to M_0.5 (CNR, 10.9±5.5) and all VMI series that showed highest values at 70keV (CNR, 13.5±6.6; all PVMI+ series, which was significantly higher (P≤0.039) compared to 70-keV VMI (0.914) and M_0.5 series (0.916). Noise-optimized VMI+ series at 40keV improve diagnostic accuracy for the detection and rule-out of endoleaks after EVAR. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Intestinal obstruction from diaphragmatic hernia following colonoscopy.

    Science.gov (United States)

    Rustagi, Tarun

    2011-05-01

    Diaphragmatic hernias caused or exacerbated by colonoscopy are rare with only few cases reported. The author reports here an unusual case of herniation and incarceration of the colon into the left thoracic cavity without bowel perforation after an uneventful screening colonoscopy, through an occult focal diaphragmatic weakness from the patient's prior trauma.

  4. Simulation-based training for colonoscopy

    DEFF Research Database (Denmark)

    Preisler, Louise; Svendsen, Morten Bo Søndergaard; Nerup, Nikolaj

    2015-01-01

    The aim of this study was to create simulation-based tests with credible pass/fail standards for 2 different fidelities of colonoscopy models. Only competent practitioners should perform colonoscopy. Reliable and valid simulation-based tests could be used to establish basic competency in colonosc...

  5. Feasibility of joystick guided colonoscopy.

    Science.gov (United States)

    Rozeboom, Esther D; Broeders, Ivo A M J; Fockens, Paul

    2015-09-01

    The flexible endoscope is increasingly used to perform minimal invasive interventions. A novel add-on platform allows single-person control of both endoscope and instrument at the site of intervention. The setup changes the current routine of handling the endoscope. This study aims to determine if the platform allows effective and efficient manipulation to position the endoscope at potential intervention sites throughout the bowel. Five experts in flexible endoscopy first performed three colonoscopies on a computer simulator using the conventional angulation wheels. Next they trained with the joystick interface to achieve their personal level of intubation time with low pain score. 14 PhD students (novices) without hands-on experience performed the same colonoscopy case using either the conventional angulation wheels or joystick interface. Both novice groups trained to gain the average expert level. The cecal intubation time, pain score and visualization performance (% of bowel wall) were recorded. All experts reached their personal intubation time in 6 ± 6 sessions. Three experts completed their learning curve with low pain score in 8 ± 6 sessions. The novices required 11 ± 6 sessions using conventional angulation wheels, and 12 ± 6 sessions using the joystick interface. There was no difference in the visualization performance between the novice and between the expert groups. This study shows that the add-on platform enables endoscope manipulation required to perform colonoscopy. Experts need only a relatively short training period. Novices are as effective and as efficient in endoscope manipulation when comparing the add-on platform with conventional endoscope control.

  6. Robust augmented reality registration method for localization of solid organs' tumors using CT-derived virtual biomechanical model and fluorescent fiducials.

    Science.gov (United States)

    Kong, Seong-Ho; Haouchine, Nazim; Soares, Renato; Klymchenko, Andrey; Andreiuk, Bohdan; Marques, Bruno; Shabat, Galyna; Piechaud, Thierry; Diana, Michele; Cotin, Stéphane; Marescaux, Jacques

    2017-07-01

    Augmented reality (AR) is the fusion of computer-generated and real-time images. AR can be used in surgery as a navigation tool, by creating a patient-specific virtual model through 3D software manipulation of DICOM imaging (e.g., CT scan). The virtual model can be superimposed to real-time images enabling transparency visualization of internal anatomy and accurate localization of tumors. However, the 3D model is rigid and does not take into account inner structures' deformations. We present a concept of automated AR registration, while the organs undergo deformation during surgical manipulation, based on finite element modeling (FEM) coupled with optical imaging of fluorescent surface fiducials. Two 10 × 1 mm wires (pseudo-tumors) and six 10 × 0.9 mm fluorescent fiducials were placed in ex vivo porcine kidneys (n = 10). Biomechanical FEM-based models were generated from CT scan. Kidneys were deformed and the shape changes were identified by tracking the fiducials, using a near-infrared optical system. The changes were registered automatically with the virtual model, which was deformed accordingly. Accuracy of prediction of pseudo-tumors' location was evaluated with a CT scan in the deformed status (ground truth). In vivo: fluorescent fiducials were inserted under ultrasound guidance in the kidney of one pig, followed by a CT scan. The FEM-based virtual model was superimposed on laparoscopic images by automatic registration of the fiducials. Biomechanical models were successfully generated and accurately superimposed on optical images. The mean measured distance between the estimated tumor by biomechanical propagation and the scanned tumor (ground truth) was 0.84 ± 0.42 mm. All fiducials were successfully placed in in vivo kidney and well visualized in near-infrared mode enabling accurate automatic registration of the virtual model on the laparoscopic images. Our preliminary experiments showed the potential of a biomechanical model with fluorescent

  7. Dual-energy CT in the assessment of mediastinal lymph nodes: Comparative study of virtual non-contrast and true non-contrast images

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seon Young; Kim, Yoo Kyung; Cho, Hyun Hae; Choi, Mi Joo; Shim, Sung Shine; Lee, Jeong Kyong; Baek, Seung Yon [School of Medicine, Ewha Womans University, Seou (Korea, Republic of)

    2013-06-15

    To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes. A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation ≤ the aorta; 1, > the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed. CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 ± 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (κ value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245). VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.

  8. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    Energy Technology Data Exchange (ETDEWEB)

    Abdoli, Mehrsima; Jong, Johan R. de; Pruim, Jan; Dierckx, Rudi A.J.O. [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Zaidi, Habib [University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-12-15

    Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over- or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron emission tomography (PET) images. Since this degrades the diagnostic quality of the images, metal artefact reduction (MAR) prior to attenuation correction is required. The proposed MAR method, referred to as virtual sinogram-based technique, replaces the projection bins of the sinogram that are influenced by metallic implants by a 2-D Clough-Tocher cubic interpolation scheme performed in an irregular grid, called Delaunay triangulated grid. To assess the performance of the proposed method, a physical phantom and 30 clinical PET/CT studies including hip prostheses were used. The results were compared to the method implemented on the Siemens Biograph mCT PET/CT scanner. Both phantom and clinical studies revealed that the proposed method performs equally well as the Siemens MAR method in the regions corresponding to bright streaking artefacts and the artefact-free regions. However, in regions corresponding to dark streaking artefacts, the Siemens method does not seem to appropriately correct the tracer uptake while the proposed method consistently increased the uptake in the underestimated regions, thus bringing it to the expected level. This observation is corroborated by the experimental phantom study which demonstrates that the proposed method approaches the true activity concentration more closely. The proposed MAR method allows more accurate CT-based attenuation correction of PET images and prevents misinterpretation of tracer uptake, which might be biased owing to the propagation of bright and dark streaking artefacts from CT images to the PET data following the attenuation correction procedure. (orig.)

  9. Virtual bite registration using intraoral digital scanning, CT and CBCT: In vitro evaluation of a new method and its implication for orthognathic surgery.

    Science.gov (United States)

    Nilsson, Johanna; Richards, Robert Geoff; Thor, Andreas; Kamer, Lukas

    2016-09-01

    Three-dimensional (3D) computer-assisted planning requires detailed visualisation of the craniomaxillofacial region and interocclusal relationship. The aim of this study was to establish and evaluate a method to create a 3D model of the craniomaxillofacial region and to adopt intraoral digital scanning to place the lower jaw into a centric relation (CR) without the need of additional plaster casts and model surgery. A standard plastic skull modified by metallic dental wires and brackets was subjected to computed tomography (CT), cone beam computed tomography (CBCT), and intraoral digital scanning. We evaluated two different virtual bite registrations, a digital scan of the buccal dental surfaces and scanning of the wax bites to position the lower jaw into a CR, and assessed the accuracy of the integration of intraoral scanning to the CT/CBCT scans. The mean registration error of corresponding mesh points for the CT and intraoral scanned images was 0.15 ± 0.12 mm, while this error was 0.18 ± 0.13 mm for the CBCT and intraoral scanned images. The mean accuracy of the two virtual bite registrations ranged from 0.41 to 0.49 mm (buccal scan technique) and from 0.65 to 1.3 mm (virtualised wax bite technique). A method for virtual bite registration was developed. It has the potential to eliminate plaster casts and model surgery and may facilitate 3D computer-assisted planning of orthognathic surgery cases.

  10. Creation of individual ideally shaped stents using multi-slice CT: in vitro results from the semi-automatic virtual stent (SAVS) designer.

    Science.gov (United States)

    Hyodoh, Hideki; Katagiri, Yoshimi; Sakai, Toyohiko; Hyodoh, Kazusa; Akiba, Hidenari; Hareyama, Masato

    2005-08-01

    To plan stent-grafting for thoracic aortic aneurysm with complicated morphology, we created a virtual stent-grafting program [Semi Automatic Virtual Stent (SAVS) designer] using three-dimensional CT data. The usefulness of the SAVS designer was evaluated by measurement of transformed anatomical and straight stents. Curved model images (source, multi-planer reconstruction and volume rendering) were created, and a hollow virtual stent was produced by the SAVS designer. A straight Nitinol stent was transformed to match the curved configuration of the virtual stent. The accuracy of the anatomical stent was evaluated by experimental strain phantom studies in comparison with the straight stent. Mean separation length was 0 mm in the anatomical stent [22 mm outer diameter (OD)] and 5 mm in the straight stent (22 mm OD). The straight stent strain voltage was four times that of the anatomical stent at the stent end. The anatomical stent is useful because it fits the curved structure of the aorta and reduces the strain force compared to the straight stent. The SAVS designer can help to design and produce the anatomical stent.

  11. Colonoscopy

    Science.gov (United States)

    ... that is clear and liquid. Stool inside your intestine can prevent your doctor from clearly seeing the lining. You may need to follow a clear liquid ... doctor slowly removes the scope and examines the lining of your large intestine again. For the procedure, you will lie on ...

  12. Colonoscopy

    Science.gov (United States)

    ... of the scope. If needed, procedures, such as laser therapy , are also done. ... that requires surgery to repair Infection needing antibiotic therapy (very rare) Reaction to the medicine you are given to relax, causing breathing problems or low blood pressure

  13. Bladder tumors:dynamic contrast-enhanced axial imaging, multiplanar reformation, three-dimensional reconstruction and virtual cystoscopy using helical CT

    Institute of Scientific and Technical Information of China (English)

    王东; 张挽时; 熊明辉; 喻敏; 徐家兴

    2004-01-01

    Background There have been few studies to evaluate the effects of helical CT on bladder tumor. This study was to evaluate the clinical applications of helical CT dynamic contrast-enhanced axial imaging, multiplanar reformation (MPR), three-dimensional (3D) reconstruction and virtual cystoscopy (CTVC) in bladder tumors. Methods The precontrast and four-phase postcontrast helical CT scans were performed in 42 patients with bladder tumors confirmed by conventional cystoscopy and pathology. MPR, 3D and CTVC images were generated from the volumetric data of the excretory phase. The results were then compared with the findings of conventional cystoscopy and surgery in a double-blinded mode. Results The sensitivity of the axial, 3D and CTVC images in detecting the bladder tumors were 90.8%, 76.9% and 95.4% respectively. The dynamic contrast-enhanced axial images could provide excellent intramural and extravesical information, and the accuracy in preoperative tumor staging was 87.7%. MPR could directly demonstrate the origin and extravesical invasions of the tumors and their relation to the ureter. 3D and CTVC images were useful for displaying the surface morphology of the tumor and the relationship between the tumor and the ureteric orifices, whereas CTVC could depict the tumors smaller than 5 mm that were not seen on the axial images.Conclusions The combination of axial, MPR, 3D and CTVC images with helical CT can provide comprehensive information on bladder tumor.

  14. Noise-Optimized Virtual Monoenergetic Dual-Energy CT Improves Diagnostic Accuracy for the Detection of Active Arterial Bleeding of the Abdomen.

    Science.gov (United States)

    Martin, Simon S; Wichmann, Julian L; Scholtz, Jan-Erik; Leithner, Doris; D'Angelo, Tommaso; Weyer, Hendrik; Booz, Christian; Lenga, Lukas; Vogl, Thomas J; Albrecht, Moritz H

    2017-09-01

    To evaluate diagnostic accuracy of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique for detection of active arterial abdominal bleeding on dual-energy (DE) CT angiography compared with standard image reconstruction. DE CT angiography data sets of 71 patients (46 men; age 63.6 y ± 13.3) with suspected arterial bleeding of the abdomen or pelvis were reconstructed with standard linearly blended (F_0.5), VMI+, and traditional virtual monoenergetic imaging (VMI) algorithms in 10-keV increments from 40 to 100 keV. Attenuation measurements were performed in the descending aorta, area of hemorrhage, and feeding artery to calculate contrast-to-noise ratios (CNRs) in patients with active arterial bleeding. Based on quantitative image quality results, the best series for each reconstruction technique were chosen to analyze the diagnostic performance of 3 blinded radiologists. DE CT angiography showed acute arterial bleeding in 36 patients. Mean CNR was superior in 40-keV VMI+ compared with VMI series (all P VMI and F_0.5 (21.6 ± 7.9, 12.9 ± 4.7, and 10.4 ± 3.6) images. Area under the curve analysis for detection of arterial bleeding showed significantly superior (P VMI+ (0.963) compared with 70-keV VMI (0.775) and F_0.5 (0.817) series. Diagnostic accuracy in patients with active arterial bleeding of the abdomen can be significantly improved using VMI+ reconstructions at 40 keV compared with standard linearly blended and traditional VMI series in DE CT angiography. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  15. Simulation-based training for colonoscopy

    DEFF Research Database (Denmark)

    Preisler, Louise; Svendsen, Morten Bo Søndergaard; Nerup, Nikolaj;

    2015-01-01

    The aim of this study was to create simulation-based tests with credible pass/fail standards for 2 different fidelities of colonoscopy models.Only competent practitioners should perform colonoscopy. Reliable and valid simulation-based tests could be used to establish basic competency in colonosco...... reliable and valid assessments of competence in colonoscopy and credible pass/fail standards were established for both the tests. We propose to use these standards in simulation-based training programs before proceeding to supervised training on patients....

  16. Colonoscopy Surveillance After Colorectal Cancer Resection: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

    Science.gov (United States)

    Kahi, Charles J; Boland, C Richard; Dominitz, Jason A; Giardiello, Francis M; Johnson, David A; Kaltenbach, Tonya; Lieberman, David; Levin, Theodore R; Robertson, Douglas J; Rex, Douglas K

    2016-03-01

    The US Multi-Society Task Force has developed updated recommendations to guide health care providers with the surveillance of patients after colorectal cancer (CRC) resection with curative intent. This document is based on a critical review of the literature regarding the role of colonoscopy, flexible sigmoidoscopy, endoscopic ultrasound, fecal testing and CT colonography in this setting. The document addresses the effect of surveillance, with focus on colonoscopy, on patient survival after CRC resection, the appropriate use and timing of colonoscopy for perioperative clearing and for postoperative prevention of metachronous CRC, specific considerations for the detection of local recurrence in the case of rectal cancer, as well as the place of CT colonography and fecal tests in post-CRC surveillance.

  17. Polyp Segmentation in NBI Colonoscopy

    Science.gov (United States)

    Gross, Sebastian; Kennel, Manuel; Stehle, Thomas; Wulff, Jonas; Tischendorf, Jens; Trautwein, Christian; Aach, Til

    Endoscopic screening of the colon (colonoscopy) is performed to prevent cancer and to support therapy. During intervention colon polyps are located, inspected and, if need be, removed by the investigator. We propose a segmentation algorithm as a part of an automatic polyp classification system for colonoscopic Narrow-Band images. Our approach includes multi-scale filtering for noise reduction, suppression of small blood vessels, and enhancement of major edges. Results of the subsequent edge detection are compared to a set of elliptic templates and evaluated. We validated our algorithm on our polyp database with images acquired during routine colonoscopic examinations. The presented results show the reliable segmentation performance of our method and its robustness to image variations.

  18. Can Technology Improve the Quality of Colonoscopy?

    Science.gov (United States)

    Thirumurthi, Selvi; Ross, William A; Raju, Gottumukkala S

    2016-07-01

    In order for screening colonoscopy to be an effective tool in reducing colon cancer incidence, exams must be performed in a high-quality manner. Quality metrics have been presented by gastroenterology societies and now include higher adenoma detection rate targets than in the past. In many cases, the quality of colonoscopy can often be improved with simple low-cost interventions such as improved procedure technique, implementing split-dose bowel prep, and monitoring individuals' performances. Emerging technology has expanded our field of view and image quality during colonoscopy. We will critically review several technological advances in the context of quality metrics and discuss if technology can really improve the quality of colonoscopy.

  19. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... Earn your CME from the convenience of your home or office by accessing ACG's web-based educational ... ACG Blog Follow ACG on Twitter Patients ACG Home / Media / What to Expect During a Colonoscopy What ...

  20. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... her through the day of her exam. The video reviews all clinical information regarding colonoscopy and urges viewers to follow all instructions from their health care providers. It runs for ...

  1. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... the day of her exam. The video reviews all clinical information regarding colonoscopy and urges viewers to follow all instructions from their health care providers. It runs ...

  2. What to Expect During a Colonoscopy

    Medline Plus

    Full Text Available ... Patient Website Patient Assistance Programs Practice Management Practice Management From articles to educational programs, ACG provides you ... for Clinical Research and Education, underscores the lifesaving importance of colorectal screening by colonoscopy. The video instills ...

  3. Peri-colonic haematoma following routine colonoscopy

    Directory of Open Access Journals (Sweden)

    Felicity Page

    2016-02-01

    Conclusion: This case highlights an unusual but potentially life threatening complication following colonoscopy. Endoscopists and clinicians should be aware of the diagnosis to allow for early recognition and appropriate management.

  4. Colonoscopy Screening Information Preferences Among Urban Hispanics

    OpenAIRE

    Ellison, Jennie; Jandorf, Lina; DuHamel, Katherine

    2011-01-01

    Existing disparities are evident in colorectal cancer (CRC) screening. We sought to assess preferred sources of colonoscopy screening information among Hispanics in East Harlem, NY. Face-to-face interviews were conducted among average-risk for CRC, non-symptomatic Hispanics in community-based sites and health clinics. SPSS 16 analysis explored the relationships between sociodemographic and health care variables and preferred sources of colonoscopy information for 395 participants. The top fou...

  5. Multidetector CT evaluation of central airways stenoses: Comparison of virtual bronchoscopy, minimal-intensity projection, and multiplanar reformatted images

    OpenAIRE

    Sundarakumar, Dinesh K; Bhalla, Ashu S; Raju Sharma; Smriti Hari; Randeep Guleria; Khilnani, Gopi C.

    2011-01-01

    Aims: To evaluate the diagnostic utility of virtual bronchoscopy, multiplanar reformatted images, and minimal-intensity projection in assessing airway stenoses. Settings and Design: It was a prospective study involving 150 patients with symptoms of major airway disease. Materials and Methods: Fifty-six patients were selected for analysis based on the detection of major airway lesions on fiber-optic bronchoscopy (FB) or routine axial images. Comparisons were made between axial images, virtual ...

  6. Effective colonoscopy training techniques: strategies to improve patient outcomes

    Directory of Open Access Journals (Sweden)

    Papanikolaou IS

    2016-03-01

    Full Text Available Ioannis S Papanikolaou,1 Pantelis S Karatzas,2 Lazaros T Varytimiadis,2 Athanasios Tsigaridas,2 Michail Galanopoulos,2 Nikos Viazis,2 Dimitrios G Karamanolis21Hepato-gastroenterology Unit, 2nd Department of Internal Medicine, Attikon University General Hospital, University of Athens, 2Gastroenterology Department, Evangelismos Hospital, Athens, GreeceAbstract: Colonoscopy has substantially evolved during the last 20 years and many different training techniques have been developed in order to improve the performance of endoscopists. The most known are mechanical simulators, virtual reality simulators, computer-simulating endoscopy, magnetic endoscopic imaging, and composite and explanted animal organ simulators. Current literature generally indicates that the use of simulators improves performance of endoscopists and enhances safety of patients, especially during the initial phase of training. Moreover, newer endoscopes and imaging techniques such as high-definition colonoscopes, chromocolonoscopy with dyes spraying, and third-eye retroscope have been incorporated in everyday practice, offering better visualization of the colon and detection of polyps. Despite the abundance of these different technological features, training devices are not widely used and no official guideline or specified training algorithm or technique for lower gastrointestinal endoscopy has been evolved. In this review, we present the most important training methods currently available and evaluate these using existing literature. We also try to propose a training algorithm for novice endoscopists.Keywords: endoscopy, colonoscopy, teaching techniques, simulator, endoscopists, colon, polyps

  7. Use of dual-energy CT and virtual non-calcium techniques to evaluate post-traumatic bone bruises in knees in the subacute setting

    Energy Technology Data Exchange (ETDEWEB)

    Ai, Songtao [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Shanghai Ninth People' s Hospital, Department of Radiology, Shanghai (China); Qu, Mingliang; Glazebrook, Katrina N.; Liu, Yu; Leng, Shuai; McCollough, Cynthia H. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Rhee, Peter C. [Mayo Clinic, Department of Orthopedics, Rochester, MN (United States)

    2014-09-15

    The purpose of this study was to determine the ability of dual-energy computed tomography (DECT) and virtual non-calcium (VNCa) imaging to detect magnetic resonance imaging (MRI)-demonstrated bone bruises several weeks after unilateral knee injury. Patients with unilateral knee injury and MRI-confirmed bone bruises who had undergone a DECT scan of both knees were retrospectively identified. Two radiologists evaluated VNCa images for bruises in four regions per knee without knowing the MRI results. The mean CT numbers were calculated for the lesion-positive and lesion-negative regions of the injured knee, and the contralateral knee. Fourteen patients with a total of 36 regions positive for bone bruises on MRI were identified. The median delay between injury and DECT was 37 days (range, 11-99 days). The mean CT numbers in VNCa images for lesion-positive and lesion-negative regions were -7.6 ± 24.9 HU and -58.2 ± 19.5 HU, respectively. There were no significant differences in mean CT number between the lesion-negative regions in the injured knee and the contralateral knee. No resolution of bruising was seen before week 5, and bone bruising was still identifiable in one out of the two patients scanned at 10 weeks following injury. DECT and VNCa images can identify bone bruising for at least 10 weeks after injury. (orig.)

  8. Clinical and Molecular Characteristics of Post-Colonoscopy Colorectal Cancer

    DEFF Research Database (Denmark)

    Stoffel, Elena M; Erichsen, Rune; Frøslev, Trine;

    2016-01-01

    BACKGROUND AND AIMS: Colonoscopy provides incomplete protection from colorectal cancer (CRC), but determinants of post-colonoscopy CRC are not well understood. We compared clinical features and molecular characteristics of CRCs diagnosed at different time intervals after a previous colonoscopy....... METHODS: We performed a population-based, cross-sectional study of incident CRC cases in Denmark (2007-2011), categorized as post-colonoscopy or detected during diagnostic colonoscopy (in patients with no prior colonoscopy). We compared prevalence of proximal location and DNA mismatch repair deficiency (d...

  9. A cone-beam CT based technique to augment the 3D virtual skull model with a detailed dental surface.

    Science.gov (United States)

    Swennen, G R J; Mommaerts, M Y; Abeloos, J; De Clercq, C; Lamoral, P; Neyt, N; Casselman, J; Schutyser, F

    2009-01-01

    Cone-beam computed tomography (CBCT) is used for maxillofacial imaging. 3D virtual planning of orthognathic and facial orthomorphic surgery requires detailed visualisation of the interocclusal relationship. This study aimed to introduce and evaluate the use of a double CBCT scan procedure with a modified wax bite wafer to augment the 3D virtual skull model with a detailed dental surface. The impressions of the dental arches and the wax bite wafer were scanned for ten patient separately using a high resolution standardized CBCT scanning protocol. Surface-based rigid registration using ICP (iterative closest points) was used to fit the virtual models on the wax bite wafer. Automatic rigid point-based registration of the wax bite wafer on the patient scan was performed to implement the digital virtual dental arches into the patient's skull model. Probability error histograms showed errors of wax bite wafer to set-up a 3D virtual augmented model of the skull with detailed dental surface.

  10. Abdominal CT: An intra-individual comparison between virtual monochromatic spectral and polychromatic 120-kVp images obtained during the same examination

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yoshitake, E-mail: yamada@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Jinzaki, Masahiro, E-mail: jinzaki@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hosokawa, Takahiro, E-mail: snowglobe@infoseek.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Tanami, Yutaka, E-mail: tanami@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Abe, Takayuki, E-mail: tabe@z5.keio.jp [Center for Clinical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Kuribayashi, Sachio, E-mail: skuribay@med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan)

    2014-10-15

    Highlights: • We compared virtual monochromatic spectral (VMS) images with 120-kVp images. • VMS images are generated using accurate two-material beam-hardening correction. • Abdominal 70-keV VMS images provide better image quality than 120-kVp images. • Iterative reconstruction can further improve the image quality of VMS images. - Abstract: Objectives: To compare quantitative and subjective image quality between virtual monochromatic spectral (VMS) and conventional polychromatic 120-kVp imaging performed during the same abdominal computed tomography (CT) examination. Materials and methods: Our institutional review board approved this prospective study; each participant provided written informed consent. 51 patients underwent sequential fast kVp-switching dual-energy (80/140 kVp, volume CT dose index: 12.7 mGy) and single-energy (120-kVp, 12.7 mGy) abdominal enhanced CT over an 8 cm scan length with a random acquisition order and a 4.3-s interval. VMS images with filtered back projection (VMS-FBP) and adaptive statistical iterative reconstruction (so-called hybrid IR) (VMS-ASIR) (at 70 keV), as well as 120-kVp images with FBP (120-kVp-FBP) and ASIR (120-kVp-ASIR), were generated from dual-energy and single-energy CT data, respectively. The objective image noises, signal-to-noise ratios and contrast-to-noise ratios of the liver, kidney, pancreas, spleen, portal vein and aorta, and the lesion-to-liver and lesion-to-kidney contrast-to-noise ratios were measured. Two radiologists independently and blindly assessed the subjective image quality. The results were analyzed using the paired t-test, Wilcoxon signed rank sum test and mixed-effects model with Bonferroni correction. Results: VMS-ASIR images were superior to 120-kVp-FBP, 120-kVp-ASIR and VMS-FBP images for all the quantitative assessments and the subjective overall image quality (all P < 0.001), while VMS-FBP images were superior to 120-kVp-FBP and 120-kVp-ASIR images (all P < 0.004). Conclusions: VMS

  11. A cone-beam CT based technique to augment the 3D virtual skull model with a detailed dental surface.

    NARCIS (Netherlands)

    Swennen, G.R.; Mommaerts, M.Y.; Abeloos, J.V.S.; Clercq, C. De; Lamoral, P.; Neyt, N.; Casselman, J.W.; Schutyser, F.A.C.

    2009-01-01

    Cone-beam computed tomography (CBCT) is used for maxillofacial imaging. 3D virtual planning of orthognathic and facial orthomorphic surgery requires detailed visualisation of the interocclusal relationship. This study aimed to introduce and evaluate the use of a double CBCT scan procedure with a mod

  12. Virtual monochromatic imaging in dual-source and dual-energy CT for visualization of acute ischemic stroke

    Science.gov (United States)

    Hara, Hidetake; Muraishi, Hiroshi; Matsuzawa, Hiroki; Inoue, Toshiyuki; Nakajima, Yasuo; Satoh, Hitoshi; Abe, Shinji

    2015-07-01

    We have recently developed a phantom that simulates acute ischemic stroke. We attempted to visualize an acute-stage cerebral infarction by using dual-energy Computed tomography (DECT) to obtain virtual monochromatic images of this phantom. Virtual monochromatic images were created by using DECT voltages from 40 to 100 keV in steps of 10 keV and from 60 to 80 keV in steps of 1 keV, under three conditions of the tube voltage with thin (Sn) filters. Calculation of the CNR values allowed us to evaluate the visualization of acute-stage cerebral infarction. The CNR value of a virtual monochromatic image was the highest at 68 keV under 80 kV / Sn 140 kV, at 72 keV under 100 kV / Sn 140 kV, and at 67 keV under 140 kV / 80 kV. The CNR values of virtual monochromatic images at voltages between 65 and 75 keV were significantly higher than those obtained for all other created images. Therefore, the optimal conditions for visualizing acute ischemic stroke were achievable.

  13. Patient Non-adherence and Cancellations Are Higher for Screening Colonoscopy Compared with Surveillance Colonoscopy.

    Science.gov (United States)

    Greenspan, Michael; Chehl, Navdeep; Shawron, Krista; Barnes, Lisa; Li, Hong; Avery, Elizabeth; Sims, Shannon; Losurdo, John; Mobarhan, Sohrab; Melson, Joshua

    2015-10-01

    A significant proportion of the eligible population is non-adherent to colonoscopy for colorectal cancer (CRC) screening. To define the demographic and clinical variables associated with non-adherence and multiple cancellations to scheduled colonoscopy within 1 year in a CRC screening and adenomatous polyp surveillance population. This was an observational cohort study of 617 consecutive patients scheduled to undergo colonoscopy at an outpatient academic tertiary care center for CRC screening or adenomatous polyp surveillance from January 2012 to September 2012. Overall, 551 patients (89.3%) were adherent and 66 (10.7%) were non-adherent to scheduled colonoscopy at 1 year. The relative risk for non-adherence was 5.42 [95% confidence interval (CI) 2.74-10.75] in patients undergoing colonoscopy for screening compared to those for surveillance (16.7 vs. 3.5% non-adherence, respectively, P non-adherence [odds ratio (OR) 12.69, 95% CI 4.18-38.51] and multiple cancellations (OR 2.33, 95% CI 1.27-4.31) by multiple regression analysis. Patients undergoing colonoscopy for CRC screening are significantly less likely to attend their scheduled procedure within a year and have more procedure cancellations than those undergoing surveillance colonoscopy.

  14. CT colonography for synchronous colorectal lesions in patients with colorectal cancer: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    McArthur, D.R.; Karandikar, S.S. [Heart of England NHS Foundation Trust (Teaching), Department of Surgery, Birmingham (United Kingdom); Mehrzad, H.; Patel, R.; Dadds, J.; Pallan, A.; Roy-Choudhury, S. [Heart of England NHS Foundation Trust (Teaching), Department of Radiology, Birmingham (United Kingdom)

    2010-03-15

    To assess accuracy of CT colonography (CTC) in identifying synchronous lesions in patients with colorectal carcinoma. This study included 174 consecutive patients undergoing CTC as part of staging or primary investigation where a colorectal cancer was diagnosed between 2004 and 2007. Prone unenhanced and portal phase enhanced supine series with air or CO{sub 2} distension were acquired using 4- or 16-slice CT (Toshiba) and read by 2D {+-} 3D formats. Synchronous lesions were classified according to American College of Radiology's (ACR) polyp classification. Segmental gold standard was flexible sigmoidoscopy/colonoscopy within 1 year and/or histology of colonic resection supplemented by follow-up. Nine patients without gold standard were excluded. Sensitivity, specificity and accuracy were calculated on a per polyp, per patient and per segment basis and discrepancies analysed. Direct comparable data were available for 764/990 colonic segments from 165 patients. Of 41 (C2-C4) synchronous lesions on ''gold standard'', 33 were correctly identified on virtual colonoscopy (VC), overall per polyp sensitivity was 80.5%, with detection rates of 20/24 C3 (83.3%) and 3/3 C4 (100%) with per patient and per segment specificity of 95.4% and 99.2%, respectively. CTC is an accurate technique to assess for significant synchronous lesions in patients with colorectal cancer and is applicable for total pre-operative colonic visualisation. (orig.)

  15. Quality of colonoscopy in Lynch syndrome.

    Science.gov (United States)

    Niv, Yaron; Moeslein, Gabriela; Vasen, Hans F A; Karner-Hanusch, Judith; Lubinsky, Jan; Gasche, Christoph

    2014-12-01

    Lynch syndrome (LS) accounts for 2 - 4 % of all colorectal cancers. Affected family members have a germline mutation in one of the DNA mismatch repair genes MLH1, PMS2, MSH2, or MSH6, and a lifetime risk for development of colorectal cancer of 25 - 75 %. Current guidelines recommend annual to biannual surveillance colonoscopy in mutation carriers. Several factors may predict failure to prevent interval cancer in LS: more lesions in the right colon; more flat ("non polypoid") and lateral growing polyps; small adenomas may already harbor high grade dysplasia or a high percentage of villous component and become advanced adenomas; there is a short duration of the adenoma - carcinoma sequence; synchronous lesions have high prevalence; patients are younger and less tolerant to colonoscopy (need more sedation); and repeated colonoscopies are needed for lifelong surveillance (patient experience is important for compliance). In order to prevent cancer in LS patients, surveillance colonoscopy should be performed in an endoscopic unit experienced with LS, every 1 - 2 years, starting at age 20 - 25 years, or 10 years younger than the age of first diagnosis in the family (whichever is first), and yearly after the age of 40 years. Colonoscopy in LS patients should be a very meticulous and precise procedure (i. e. taking sufficient withdrawal time, documentation of such warranted), with removal of all of the polyps, special attention to the right colon and alertness to flat lesions. Following quality indicators such as successful cleansing of the colon and removal of every polyp will probably improve prevention of interval cancers. At this moment, none of the new endoscopic techniques have shown convincing superiority over conventional high resolution white light colonoscopy.

  16. Virtual iron concentration imaging based on dual-energy CT for noninvasive quantification and grading of liver iron content: An iron overload rabbit model study

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xian Fu; Yang, Yi; Xie, Xue Qian; Zhang, Huan; Chai, Wei Min; Yan, Fu Hua [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Ruijin Hospital, Shanghai (China); Yan, Jing [Siemens Shanghai Medical Equipment Ltd., Shanghai (China); Wang, Li [Fudan University, Center of Analysis and Measurement, Shanghai (China); Schmidt, Bernhard [Siemens AG, Healthcare Sector, Forchheim (Germany)

    2015-09-15

    To assess the accuracy of liver iron content (LIC) quantification and grading ability associated with clinical LIC stratification using virtual iron concentration (VIC) imaging on dual-energy CT (DECT) in an iron overload rabbit model. Fifty-one rabbits were prepared as iron-loaded models by intravenous injection of iron dextran. DECT was performed at 80 and 140 kVp. VIC images were derived from an iron-specific algorithm. Postmortem LIC assessments were conducted on an inductively coupled plasma (ICP) spectrometer. Correlation between VIC and LIC was analyzed. VIC were stratified according to the corresponding clinical LIC thresholds of 1.8, 3.2, 7.0, and 15.0 mg Fe/g. Diagnostic performance of stratification was evaluated by receiver operating characteristic analysis. VIC linearly correlated with LIC (r = 0.977, P < 0.01). No significant difference was observed between VIC-derived LICs and ICP (P > 0.05). For the four clinical LIC thresholds, the corresponding cutoff values of VIC were 19.6, 25.3, 36.9, and 61.5 HU, respectively. The highest sensitivity (100 %) and specificity (100 %) were achieved at the threshold of 15.0 mg Fe/g. Virtual iron concentration imaging on DECT showed potential ability to accurately quantify and stratify hepatic iron accumulation in the iron overload rabbit model. (orig.)

  17. Dual-source dual-energy CT angiography with virtual non-enhanced images and iodine map for active gastrointestinal bleeding: Image quality, radiation dose and diagnostic performance

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hao, E-mail: sunhao_robert@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Hou, Xin-Yi, E-mail: hxy_pumc@126.com [Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); Xue, Hua-Dan, E-mail: bjdanna95@hotmail.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Li, Xiao-Guang, E-mail: xglee88@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Jin, Zheng-Yu, E-mail: zhengyu_jin@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Qian, Jia-Ming, E-mail: qjiaming57@gmail.com [Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Yu, Jian-Chun, E-mail: yu-jch@163.com [Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Zhu, Hua-Dong, E-mail: huadongzhu@hotmail.com [Department of Emergency, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China)

    2015-05-15

    Highlights: • GIB is a common gastrointestinal emergency with a high mortality rate. • Detection and localization of GIB source are important for imaging modality. • DSDECTA using a dual-phase scan protocol is clinically feasible. • DSDECTA with VNE and iodine map images can diagnose the active GIB source accurately. • DSDECTA can reduce radiation dose compared with conventional CT examination in GIB. - Abstract: Objectives: To evaluate the clinical feasibility of dual-source dual-energy CT angiography (DSDECTA) with virtual non-enhanced images and iodine map for active gastrointestinal bleeding (GIB). Methods: From June 2010 to December 2012, 112 consecutive patients with clinical signs of active GIB underwent DSDECTA with true non-enhanced (TNE), arterial phase with single-source mode, and portal-venous phase with dual-energy mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs). Virtual non-enhanced CT (VNE) image sets and iodine map were reformatted from ‘Liver VNC’ software. The mean CT number, noise, signal to noise ratio (SNR), image quality and radiation dose were compared between TNE and VNE image sets. Two radiologists, blinded to clinical data, interpreted images from DSDECTA with TNE (protocol 1), and DSDECTA with VNE and iodine map (protocol 2) respectively, with discordant interpretation resolved by consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Receiver–operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated for CT protocols 1 and 2, respectively. Results: There was no significant difference in mean CT numbers of all organs (including liver, pancreas, spleen, kidney, abdominal aorta, and psoas muscle) (P > 0.05). Lower noise and higher SNR were found on VNE images than TNE images (P < 0.05). Image quality of VNE was lower than that of TNE without significant difference (P > 0.05). The active GIB source was identified

  18. Multidetector CT and MRI in diseases of the GI tract; Scanner multidetecteur face a l'IRM dans la pathologie du tube digestif

    Energy Technology Data Exchange (ETDEWEB)

    Bruel, J.M.; Gallix, B. [Hopital Saint-Eloi, Service de Radiologie, 34 - Montpellier (France)

    2003-04-01

    With the introduction of spiral scanning then multidetector technologies, the accuracy for diagnosing digestive tract diseases with CT has been highly improved, and CT is used more and more in the evaluation of patients with suspected gastrointestinal disorders. CT is able to demonstrate both the intramural and the extra-mural components of the disease, and has a major role in the preoperative staging and the follow-up Improvements of CT protocols, such as CT-enteroclysis, or multiplanar 2D and 3D post-processing, including now techniques for 'virtual endoscopy', lead to discuss new indications in which CT could now compete with conventional X-rays series and video-endoscopy. This precise study of the digestive wall, the peri-digestive fat, the digestive tract blood supply, may be performed by MRI, under the condition of access to high level machines and standardized protocols. MR-enteroclysis and MR-virtual colonoscopy could be performed with much lower risk for the patient, in terms of radiation dose or contrast adverse effects. Endo-luminal coils should give to MR an ultra-high resolution for analysing the different layers of the gastrointestinal wall. Learning objectives: to review how to perform CT and MRI protocols for digestive tract imaging, to recognize the CT arid MR patterns of the main digestive tract diseases, to discuss the value, limits and role of CT and MR in digestive tract diseases, to discuss the potential role of CT and MR new technological developments for digestive tract imaging in the upcoming future Conclusion: CT is nowadays a modality of choice for digestive imaging. Improvements in technologies and indications, the necessary discussion of the risks and benefits for the patient should let the radiologists consider MRI in gastrointestinal disorders as an important part of the routine activity in clinical MRI. (authors)

  19. Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Lawrence Paszat

    2017-01-01

    Full Text Available Background. The goal of this study is to examine utilization of early repeat colonoscopy ≤ 6 months after an index procedure. Methods. We identified persons having repeat colonoscopy ≤ 6 months following outpatient colonoscopy without prior colonoscopy ≤ 5 years or prior diagnosis of colorectal cancer (CRC. We modeled repeat colonoscopy using a generalized estimating equation with an exchangeable correlation structure to account for clustering of patients by endoscopist. Results. The population included 334,663 persons, 7,892 (2.36% of whom had an early repeat colonoscopy within 6 months. Overall, endoscopist prior year colonoscopy volume was inversely related to repeat ≤ 6 months. Repeat colonoscopy ≤ 6 months varied by the clinical setting of the index colonoscopy (adjusted OR = 1.41 (95% CI 1.29–1.55 at nonhospital facilities compared to teaching or community hospitals. Among those who had polypectomy or biopsy, the adjusted OR for early repeat ≤ 6 months was elevated among those whose index colonoscopy was at a nonhospital facility (OR 1.44, 95% CI 1.30–1.60, compared to those at a teaching hospital or community hospital. Conclusions. Repeat colonoscopy ≤ 6 months after an index procedure is associated with the clinical setting of the index colonoscopy.

  20. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned....... CONCLUSIONS: With the exponential development in computer processing power, CT- and MR colonography holds the promise for future colon examination with the advantages of non-invasiveness, no need for sedation, and probably no bowel preparation. A major disadvantage, however, is the radiation dose during CT...... colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy....

  1. [Colonoscopy with carbon dioxide insufflation: luxury or neccesity?].

    Science.gov (United States)

    Herráiz, Maite

    2013-01-01

    Colonoscopy is an essential diagnostic and therapeutic tool for many gastrointestinal diseases and is also a key element in the prevention and early diagnosis of colon cancer. Despite numerous technical advances, colonoscopy continues to be uncomfortable for patients, both during and after the procedure. To a large extent, the discomfort of colonoscopy depends on the need to distend the colon, which usually produces abdominal pain. Although ambient air is usually employed to expand and inflate the colon, in the last few years devices that allow carbon dioxide (CO(2)) insufflation in colonoscopy have been developed. This gas is a highly attractive option for pain-free colonoscopy.

  2. C-arm cone-beam CT virtual navigation-guided percutaneous mediastinal mass biopsy: Diagnostic accuracy and complications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungjin [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Aerospace Medical Group, Air Force Education and Training Command, Jinju (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Sang Min [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2015-12-15

    To assess the usefulness of C-arm cone-beam computed tomography (CBCT) virtual navigation-guided percutaneous mediastinal mass biopsy in terms of diagnostic accuracy and complication rates. Seventy-eight CBCT virtual navigation-guided percutaneous mediastinal mass biopsies were performed in 75 patients (M:F, 38:37; mean age, 48.55 ± 18.76 years). The procedural details, diagnostic sensitivity, specificity, accuracy and complication rate were investigated. Mean lesion size was 6.80 ± 3.08 cm, skin-to-target distance was 3.67 ± 1.80 cm, core needle biopsy rate was 96.2 % (75/78), needle indwelling time was 9.29 ± 4.34 min, total procedure time was 13.26 ± 5.29 min, number of biopsy specimens obtained was 3.13 ± 1.02, number of CBCTs performed was 3.03 ± 0.68, rate of lesion border discrimination from abutting mediastinal structures on CBCT was 26.9 % (21/78), technical success rate was 100 % (78/78), estimated effective dose was 5.33 ± 4.99 mSv, and the dose area product was 12,723.68 ± 10,665.74 mGy.cm{sup 2}. Among the 78 biopsies, 69 were malignant, 7 were benign and 2 were indeterminate. Diagnostic sensitivity, specificity and accuracy for the diagnosis of malignancies were 97.1 % (67/69), 100 % (7/7) and 97.4 % (74/76), respectively, with a complication rate of 3.85 % (3/78), all of which were small pneumothoraces. CBCT virtual navigation-guided biopsy is a highly accurate and safe procedure for the evaluation of mediastinal lesions. (orig.)

  3. NBI and NBI Combined with Magnifying Colonoscopy

    Directory of Open Access Journals (Sweden)

    Mineo Iwatate

    2012-01-01

    Full Text Available Although magnifying chromoendoscopy had been a reliable diagnostic tool, narrow-band imaging (NBI has been developed in Japan since 1999 and has now replaced the major role of chromoendoscopy because of its convenience and simplicity. In this paper, we principally describe the efficacy of magnifying chromoendoscopy and magnifying colonoscopy with NBI for detection, histological prediction, estimation of the depth of early colorectal cancer, and future prospects. Although some meta-analyses have concluded that NBI is not superior to white light imaging for detection of adenomatous polyps in screening colonoscopy, NBI with magnification colonoscopy is useful for histological prediction, or for estimating the depth of invasion. To standardize these diagnostic strategies, we will focus on the NBI International Colorectal Endoscopic (NICE classification proposed for use by endoscopists with or without a magnifying endoscope. However, more prospective research is needed to prove that this classification can be applied with satisfactory availability, feasibility, and reliability. In the future, NBI might contribute to the evaluation of real-time histological prediction during colonoscopy, which has substantial benefits for both reducing the risk of polypectomy and saving the cost of histological evaluation by resecting and discarding diminutive adenomatous polyps (resect and discard strategy.

  4. Simulation-based training for colonoscopy

    DEFF Research Database (Denmark)

    Preisler, Louise; Svendsen, Morten Bo Søndergaard; Nerup, Nikolaj;

    2015-01-01

    simulations-based modalities provided reliable and valid assessments of competence in colonoscopy and credible pass/fail standards were established for both the tests. We propose to use these standards in simulation-based training programs before proceeding to supervised training on patients....

  5. [Massive rectal blood loss after colonoscopy

    NARCIS (Netherlands)

    Kampschreur, M.T.; Kats-Ugurlu, G.; Suylen, R.J. van; Schryver, A.M. de

    2012-01-01

    A 70-year-old man presented with acute lower gastrointestinal bleeding. A colonoscopy performed one and a half months prior had revealed diverticulosis in the sigmoid colon; a small polyp located 10 cm from the anal margin had been removed at that time. The presenting patient was haemodynamically un

  6. Outpatient Provider Concentration and Commercial Colonoscopy Prices

    Directory of Open Access Journals (Sweden)

    Alexis Pozen PhD

    2015-04-01

    Full Text Available The objective was to evaluate the magnitude of various contributors to outpatient commercial colonoscopy prices, including market- and provider-level factors, especially market share. We used adjudicated fee-for-service facility claims from a large commercial insurer for colonoscopies occurring in hospital outpatient department or ambulatory surgery center from October 2005 to December 2012. Claims were matched to provider- and market-level data. Linear fixed effects regressions of negotiated colonoscopy price were run on provider, system, and market characteristics. Markets were defined as counties. There were 178 433 claims from 169 providers (104 systems. The mean system market share was 76% (SD = 0.34 and the mean real (deflated price was US$1363 (SD = 374, ranging from US$169 to US$2748. For every percentage point increase in a system or individual facility’s bed share, relative price increased by 2 to 4 percentage points; this result was stable across a number of specifications. Market population and price were also consistently positively related, though this relation was small in magnitude. No other factor explained price as strongly as market share. Price variation for colonoscopy was driven primarily by market share, of particular concern as the number of mergers increases in wake of the recession and the Affordable Care Act. Whether variation is justified by better quality care requires further research to determine whether quality is subsumed in prices.

  7. Monitoring and improving quality of colonoscopy

    NARCIS (Netherlands)

    S.C. van Doorn

    2015-01-01

    Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in the western world. High quality colonoscopy has the potential to reduce CRC mortality by detecting carcinomas in early stages and reduce its incidence by detecting and removing its main precursor lesions, adenomas. Variability

  8. Outpatient provider concentration and commercial colonoscopy prices.

    Science.gov (United States)

    Pozen, Alexis

    2015-01-01

    The objective was to evaluate the magnitude of various contributors to outpatient commercial colonoscopy prices, including market- and provider-level factors, especially market share. We used adjudicated fee-for-service facility claims from a large commercial insurer for colonoscopies occurring in hospital outpatient department or ambulatory surgery center from October 2005 to December 2012. Claims were matched to provider- and market-level data. Linear fixed effects regressions of negotiated colonoscopy price were run on provider, system, and market characteristics. Markets were defined as counties. There were 178,433 claims from 169 providers (104 systems). The mean system market share was 76% (SD = 0.34) and the mean real (deflated) price was US$1363 (SD = 374), ranging from US$169 to US$2748. For every percentage point increase in a system or individual facility's bed share, relative price increased by 2 to 4 percentage points; this result was stable across a number of specifications. Market population and price were also consistently positively related, though this relation was small in magnitude. No other factor explained price as strongly as market share. Price variation for colonoscopy was driven primarily by market share, of particular concern as the number of mergers increases in wake of the recession and the Affordable Care Act. Whether variation is justified by better quality care requires further research to determine whether quality is subsumed in prices.

  9. 双源 CT 双能量虚拟平扫对脂肪肝的诊断价值%The diagnostic value of dual energy virtual non-contrast images in hepatic steatosis with dual source CT scanner

    Institute of Scientific and Technical Information of China (English)

    王士阗; 王萱; 王禨; 徐凯; 薛华丹; 金征宇

    2014-01-01

    _目的:探讨双源 CT 双能量腹部虚拟平扫对脂肪肝的诊断价值。方法:回顾性分析采用双源 CT 行腹部双能量增强扫描诊断为脂肪肝的77例患者的平扫期(120 kV)及虚拟平扫(VNC)图像。虚拟平扫图像运用门脉期双能量(100及140 kV)图像重建而来。选择肝门层面测量真实平扫(TNC)与 VNC 图像上肝右叶、肝左叶、脾脏、下腔静脉的 CT 值及噪声,并在肝门层面测量上腹部前后径及左右径。记录整个扫描和平扫期对应的剂量长度乘积(DLP)。评价 TNC 与VNC 图像间各 CT 值及噪声的差异,分析两组图像上肝右叶噪声与前后径、左右径及平均径的关系。分别用肝/脾 CT 值比<0.8、肝/下腔静脉 CT 值比<1.0,做为诊断中重度脂肪肝的标准,比较 TNC 和 VNC 图像诊断中重度脂肪肝的一致性。结果:VNC 图像上肝左叶、右叶及脾脏的 CT 值均高于 TNC(P<0.01),差异小于10 HU。VNC 图像上各部位噪声均低于 TNC。TNC 图像上,肝右叶噪声与前后径、左右径、平均径均有中等相关性(r=0.562,0.608,P<0.01);在 VNC图像上,肝右叶噪声与上述径线值相关性弱。用肝/脾 CT 值比<0.8作为诊断重度脂肪肝的标准,VNC 与 TNC 图像诊断重度脂肪肝一致性的 kappa 值为0.591;用肝/静脉 CT 值比<1.0作为诊断标准,两种图像一致性的 kappa 值为0.458。用 VNC 代替 TNC 图像,可降低24.2%的总扫描剂量。结论:VNC 图像与 TNC 图像在诊断中重度脂肪肝上具有中等的一致性,推荐运用肝/脾 CT 值比<0.8这一诊断标准。%To investigate the value of dual energy (DE)virtual non-contrast (VNC)images in the diagno-sis of hepatic steatosis.Methods:This retrospective study was based on contrast enhanced abdominal DECT scan of 77 pa-tients with hepatic steatosis.The VNC images were reconstructed from two sets of

  10. Impact of a simulation training curriculum on technical and nontechnical skills in colonoscopy: a randomized trial.

    Science.gov (United States)

    Grover, Samir C; Garg, Ankit; Scaffidi, Michael A; Yu, Jeffrey J; Plener, Ian S; Yong, Elaine; Cino, Maria; Grantcharov, Teodor P; Walsh, Catharine M

    2015-12-01

    GI endoscopy simulation-based training augments early clinical performance; however, the optimal manner by which to deliver training is unknown. We aimed to validate a simulation-based structured comprehensive curriculum (SCC) designed to teach technical, cognitive, and integrative competencies in colonoscopy. Single-blinded, randomized, controlled trial. Endoscopic simulation course at an academic hospital. Thirty-three novice endoscopists were allocated to an SCC group or self-regulated learning (SRL) group. The SCC group received a curriculum consisting of 6 hours of didactic lectures and 8 hours of virtual reality simulation-based training with expert feedback. The SRL group was provided a list of desired objectives and was instructed to practice on the simulator for an equivalent time (8 hours). Clinical transfer was assessed during 2 patient colonoscopies using the Joint Advisory Group Direct Observation of Procedural Skills (JAG DOPS) scale. Secondary outcome measures included differences in procedural knowledge, immediate post-training simulation performance, and delayed post-training (4-6 weeks) performance during an integrated scenario test on the JAG DOPS communication and integrated scenario global rating scales. There was no significant difference in baseline or post-training performance on the simulator task. The SCC group performed superiorly during their first and second clinical colonoscopies. Additionally, the SCC group demonstrated significantly better knowledge and colonoscopy-specific performance, communication, and global performance during the integrated scenario. We were unable to measure SRL participants' effort outside of mandatory training. In addition, feedback metrics and number of available simulation cases are limited. These results support integration of endoscopy simulation into a structured curriculum incorporating instructional feedback and complementary didactic knowledge as a means to augment technical, cognitive, and

  11. Multidetector CT evaluation of central airways stenoses: Comparison of virtual bronchoscopy, minimal-intensity projection, and multiplanar reformatted images

    Directory of Open Access Journals (Sweden)

    Dinesh K Sundarakumar

    2011-01-01

    Full Text Available Aims: To evaluate the diagnostic utility of virtual bronchoscopy, multiplanar reformatted images, and minimal-intensity projection in assessing airway stenoses. Settings and Design: It was a prospective study involving 150 patients with symptoms of major airway disease. Materials and Methods: Fifty-six patients were selected for analysis based on the detection of major airway lesions on fiber-optic bronchoscopy (FB or routine axial images. Comparisons were made between axial images, virtual bronchoscopy (VB, minimal-intensity projection (minIP, and multiplanar reformatted (MPR images using FB as the gold standard. Lesions were evaluated in terms of degree of airway narrowing, distance from carina, length of the narrowed segment and visualization of airway distal to the lesion. Results: MPR images had the highest degree of agreement with FB (Κ = 0.76 in the depiction of degree of narrowing. minIP had the least degree of agreement with FB (Κ = 0.51 in this regard. The distal visualization was best on MPR images (84.2%, followed by axial images (80.7%, whereas FB could visualize the lesions only in 45.4% of the cases. VB had the best agreement with FB in assessing the segment length (Κ = 0.62. Overall there were no statistically significant differences in the measurement of the distance from the carina in the axial, minIP, and MPR images. MPR images had the highest overall degree of confidence, namely, 70.17% (n = 40. Conclusion: Three-dimensional reconstruction techniques were found to improve lesion evaluation compared with axial images alone. The technique of MPR images was the most useful for lesion evaluation and provided additional information useful for surgical and airway interventions in tracheobronchial stenosis. minIP was useful in the overall depiction of airway anatomy.

  12. Value of patient time invested in the colonoscopy screening process: time requirements for colonoscopy study.

    Science.gov (United States)

    Jonas, Daniel E; Russell, Louise B; Sandler, Robert S; Chou, Jon; Pignone, Michael

    2008-01-01

    Previous cost-effectiveness analyses of colorectal cancer screening have not considered the value of patient time despite consensus recommendations to do so. The authors sought to estimate the amount and value of patient time required for screening colonoscopy. Patients who were scheduled to undergo screening colonoscopy were recruited from a university endoscopy center. Participants completed a time diary for the screening colonoscopy process, including time spent in preparation, travel, waiting, colonoscopy, and recovery. The authors defined several time intervals and estimated their value. The primary time interval of interest, called occupied time, included preparation, travel, waiting, the colonoscopy procedure, and on-site recovery. Time was valued at the 2005 average wage rate. The authors performed sensitivity analyses to test other time intervals and wage rates. They then incorporated patient time costs into a previously published cost-effectiveness analysis of colorectal cancer screening to examine their impact. One hundred ten subjects completed the study. The sample was 57% female, 85% Caucasian, and 90% insured (40% Medicare, 4% Medicaid). The mean occupied time was 23.2 hours, worth $432 at the average wage rate. The authors estimate that including patient time costs in cost-effectiveness analysis would increase the cost per life-year saved with screening colonoscopy by 68%, from $13,100 to $22,000. Sensitivity analyses showed that the increase could range from 17% to 224% depending on the time interval valued. Patient time constitutes an important cost in colonoscopy screening and should be included in cost-effectiveness analyses.

  13. 3-D reconstruction and virtual ductoscopy of high-grade ductal carcinoma in situ of the breast with casting type calcifications using refraction-based X-ray CT.

    Science.gov (United States)

    Ichihara, Shu; Ando, Masami; Maksimenko, Anton; Yuasa, Tetsuya; Sugiyama, Hiroshi; Hashimoto, Eiko; Yamasaki, Katsuhito; Mori, Kensaku; Arai, Yoshinori; Endo, Tokiko

    2008-01-01

    Stereomicroscopic observations of thick sections, or three-dimensional (3-D) reconstructions from serial sections, have provided insights into histopathology. However, they generally require time-consuming and laborious procedures. Recently, we have developed a new algorithm for refraction-based X-ray computed tomography (CT). The aim of this study is to apply this emerging technology to visualize the 3-D structure of a high-grade ductal carcinomas in situ (DCIS) of the breast. The high-resolution two-dimensional images of the refraction-based CT were validated by comparing them with the sequential histological sections. Without adding any contrast medium, the new CT showed strong contrast and was able to depict the non-calcified fine structures such as duct walls and intraductal carcinoma itself, both of which were barely visible in a conventional absorption-based CT. 3-D reconstruction and virtual endoscopy revealed that the high-grade DCIS was located within the dichotomatous branches of the ducts. Multiple calcifications occurred in the necrotic core of the continuous DCIS, resulting in linear and branching (casting type) calcifications, a hallmark of high-grade DCIS on mammograms. In conclusion, refraction-based X-ray CT approaches the low-power light microscopic view of the histological sections. It provides high quality slice data for 3-D reconstruction and virtual ductosocpy.

  14. Assessment of carotid plaque composition using fast-kV switching dual-energy CT with gemstone detector: comparison with extracorporeal and virtual histology-intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Yuki; Kuya, Keita; Ohta, Yasutoshi; Fujii, Shinya; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago (Japan); Sakamoto, Makoto; Watanabe, Takashi [Tottori University, Division of Neurosurgery, Department of Neurological Sciences, Faculty of Medicine, Yonago (Japan); Kishimoto, Junichi; Iwata, Naoki [Tottori University Hospital, Division of Clinical Radiology, Yonago (Japan)

    2015-09-15

    The present study compares the applicability of CT carotid plaque imaging using effective Z maps using gemstone spectral imaging (GSI) with that of conventional extracorporeal carotid ultrasound (US) and virtual histology-intravascular ultrasound (VH-IVUS). We assessed stenosis in 31 carotid arteries of 30 patients. All patients underwent carotid CTA using GSI (Discovery CT750 HD, GE Healthcare). US and IVUS were examined with 25 and 8 vessels, respectively. We compared the effective Z values at noncalcified carotid plaque with the plaque components identified by US. We defined the plaque with low or low to iso intensity on US as vulnerable plaque and the plaque with iso, iso to high, and high intensity on US as stable plaque. We also performed visual assessment of color-coded effective Z maps in comparison with VH-IVUS and compared effective Z values with plaque components generated by VH-IVUS. The effective Z values at noncalcified carotid plaque were significantly lower for a group with vulnerable plaque, than with stable plaque on US (p < 0.05). Receiver operating curve analysis showed that AUC of effective Z values was 0.882 concerning the differentiation of these two groups on US. The interpretation of color-coded effective Z maps was essentially compatible with that of VH-IVUS for carotid plaque in all vessels. Effective Z values at noncalcified plaque showed significant negative correlation with the areas of fibro-fatty components generated by VH-IVUS (ρ = -0.874, p < 0.05). Effective Z maps generated by GSI can detect vulnerable carotid plaque materials. (orig.)

  15. Utility of the iodine overlay technique and virtual nonenhanced images for the preoperative T staging of colorectal cancer by dual-energy CT with tin filter technology.

    Science.gov (United States)

    Chen, Chiao-Yun; Hsu, Jui-Sheng; Jaw, Twei-Shiun; Wu, Deng-Chyang; Shih, Ming-Chen Paul; Lee, Chien-Hung; Kuo, Chao-Hung; Chen, Yi-Ting; Lai, Ming-Lai; Liu, Gin-Chung

    2014-01-01

    To evaluate the diagnostic accuracy and the potential radiation dose reduction of dual-energy CT (DECT) for tumor (T) staging of colorectal cancer (CRC) using iodine overlay (IO) and virtual nonenhanced (VNE) images. This retrospective study included 103 consecutive patients who underwent nonenhanced CT and enhanced DECT for preoperative CRC staging. Enhanced weighted-average (WA), IO and VNE images were reconstructed from enhanced 80 kVp and Sn140 kVp scans. Two radiologists assessed image qualities of the true nonenhanced (TNE) and VNE images. For T-staging, another two radiologists independently interpreted all scans in two separate reading sessions: in the first session, only images derived from the single phase DECT acquisition (IO and VNE images) were read. In the second reading session after 30 to 50 (average:42) days, the same assessment was again performed with the TNE and enhanced WA images thereby simulating conventional dual-phase single-energy CT. The tumor node metastasis (TNM) system was used for staging with histopathologic reports as gold standard. Analysis of variance was used for statistical analysis. The signal-to-noise ratios (SNRs) of the tumors and normal reference tissues showed significant correlation between the TNE and VNE images (Poverlay value (48.4 HU±12.2) and enhancement (49.4 HU±11.8) value of CRCs had no significant difference (P = 0.52).The mean image noise on TNE (5.0±1.1) and VNE (5.3±1.1) images were similar (P = 0.07). The quantitative qualities of the VNE images were mildly inferior to the TNE images. Overall accuracy of T-stage CRC when using single-phase acquisition was slightly better than the dual-phase acquisition (90.3% vs 87.4%) (P = 0.51). The mean dose of the single-phase DECT acquisition was 6.2 mSv comparing with 14.3 mSv of dual-phase. Single-phase DECT using IO and VNE images yields a high accuracy in T-staging of CRCs. Thereby, the radiation exposure of the patients can be reduced.

  16. Utility of the iodine overlay technique and virtual nonenhanced images for the preoperative T staging of colorectal cancer by dual-energy CT with tin filter technology.

    Directory of Open Access Journals (Sweden)

    Chiao-Yun Chen

    Full Text Available OBJECTIVES: To evaluate the diagnostic accuracy and the potential radiation dose reduction of dual-energy CT (DECT for tumor (T staging of colorectal cancer (CRC using iodine overlay (IO and virtual nonenhanced (VNE images. MATERIALS AND METHODS: This retrospective study included 103 consecutive patients who underwent nonenhanced CT and enhanced DECT for preoperative CRC staging. Enhanced weighted-average (WA, IO and VNE images were reconstructed from enhanced 80 kVp and Sn140 kVp scans. Two radiologists assessed image qualities of the true nonenhanced (TNE and VNE images. For T-staging, another two radiologists independently interpreted all scans in two separate reading sessions: in the first session, only images derived from the single phase DECT acquisition (IO and VNE images were read. In the second reading session after 30 to 50 (average:42 days, the same assessment was again performed with the TNE and enhanced WA images thereby simulating conventional dual-phase single-energy CT. The tumor node metastasis (TNM system was used for staging with histopathologic reports as gold standard. Analysis of variance was used for statistical analysis. RESULTS: The signal-to-noise ratios (SNRs of the tumors and normal reference tissues showed significant correlation between the TNE and VNE images (P<0.01. The mean iodine overlay value (48.4 HU±12.2 and enhancement (49.4 HU±11.8 value of CRCs had no significant difference (P = 0.52.The mean image noise on TNE (5.0±1.1 and VNE (5.3±1.1 images were similar (P = 0.07. The quantitative qualities of the VNE images were mildly inferior to the TNE images. Overall accuracy of T-stage CRC when using single-phase acquisition was slightly better than the dual-phase acquisition (90.3% vs 87.4% (P = 0.51. The mean dose of the single-phase DECT acquisition was 6.2 mSv comparing with 14.3 mSv of dual-phase. CONCLUSION: Single-phase DECT using IO and VNE images yields a high accuracy in T-staging of CRCs

  17. Development of a continuum robot for colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Hu Haiyan; Li Mantian; Wang Pengfei; Feng Yuan; Sun Lining

    2009-01-01

    A novel continuum robot for colonoscopy is presented. The aim is to develop a robot for colonoscopy which can provide the same functions as conventional colonoscope, but much less pain and discomfort for patient. In contrast to traditional rigid-link robot, the robot features a continuous backbone with no joints. The continuum robot is 300 mm in total length and 12 mm in diameter that is less than the average diameter of human colon (20 mm). The robot has a total of 4 DOF (degrees of freedom) and is actuated remotely by 6 hybrid step motors through super-elastic NiTi wires. Its shape can be changed with high dexterity, therefore ensuring its adaptability to the tortuous shape of human colon. The mechanical structure, kinematics and DSP-based control system are discussed; prototype experiments are carried out to validate the kinematics model and to show the motion performances.

  18. Utility of virtual endoscopy in coronary dual-source CT angiography: initial experience%仿真内镜用于双源CT冠状动脉成像的初步经验

    Institute of Scientific and Technical Information of China (English)

    何卫红; 陈伟; 周晖

    2011-01-01

    目的 初步探讨双源CT冠状动脉成像时利用仿真内镜诊断冠状动脉疾病的潜在价值.方法 使用Fly-through软件对40例双源CT冠状动脉成像病例行仿真内镜观察,并与CT冠状动脉成像常规方法和传统冠状动脉造影术进行比较.结果 40例患者共120支冠状动脉中,92%(110/120)的冠状动脉可行仿真内镜成像;仿真内镜判断有意义的冠状动脉狭窄正确率为85%( 41/48);常规CT冠状动脉成像不能判断的9处严重钙化,仿真内镜显示为显著或高度狭窄;4枚冠状动脉支架内和3支桥血管仿真内镜显示通畅.结论 仿真内镜可立体显示正常和病变冠状动脉腔内情况,是CT冠状动脉成像后处理方法的的重要补充.%[Objective] To explore the potential clinical value of virtual endoscopy in detecting coronary artery lesions. [Methods] Forty patients underwent dual-source CT coronary angiography. Virtual endoscopies were simulated in 120 coronary arteries using the Fly-through software, with routine imaging post-processing methods of CT coronary angiography and conventional coronary angiography as the reference standard. [Results] Virtual endo- scopies of 92% (110/120) major coronary artery were successfully performed with good image quality, and the accuracy of virtual coronary angioscopy was 85% (41/48) for detecting hemodynamically significant stenoses confirmed by conventional coronary angiography. Using virtual coronary angioscopy, 9 severe calcified coronary arteries were identified as significant or severe stenoses, while unable to estimate by routine CT coronary angiography. Virtual endoscopies of intracoronary stents (n=4) or bypass grafts (n=4) were patency. [Conclusions] Endoscopy of coronary arteries using dual-source CT allows comprehensive 3-dimensional delineation of the vessel lumen, and can be used as an important complement to the routine post-processing methods of CT coronary angiography in some cases.

  19. Torsion of Wandering Gallbladder following Colonoscopy

    Directory of Open Access Journals (Sweden)

    Sean R. Warfe

    2013-01-01

    Full Text Available Torsion of the gallbladder is an uncommon condition that may present as an acute abdomen. Its preoperative diagnosis can often be challenging due to its variable presentation, with specific sonographic signs seen infrequently. We describe, to our knowledge, the first case of torsion of a wandering gallbladder following a colonoscopy in a 69-year-old female who presented with acute abdominal pain after procedure. This was discovered intraoperatively, and after a subsequent cholecystectomy, she had an uncomplicated recovery.

  20. Intestinal disease in acquired immunodeficiency: evaluation by CT

    Energy Technology Data Exchange (ETDEWEB)

    Knollmann, F.D.; Maeurer, J.; Felix, R. [Strahlenklinik und Poliklinik, Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Augustenburger Platz 1, D-13 353 Berlin (Germany); Gruenewald, T.; Pohle, H.D. [Medizinische Klinik II mit Schwerpunkt Infektionskrankheiten, Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Augustenburger Platz 1, D-13 353 Berlin (Germany); Adler, A.; Hintze, R.E. [Klinik fuer Innere Medizin mit dem Schwerpunkt Gastroenterologie, Zentrale Interdisziplinaere Endoskopie, Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Universitaet, Augustenburger Platz 1, D-13 353 Berlin (Germany)

    1997-12-01

    Intestinal symptoms affect most AIDS patients at some point in their disease. The purpose of this study was to evaluate the use of CT in this setting. A total of 339 abdominal CT exams were reviewed for signs of intestinal disease. Abdominal CT scans of 45 patients with intestinal symptoms were compared with colonoscopy and histologic data. The CT results were correlated with CD4{sup +} T-lymphocyte counts and patient survival. More than 14 % of all abdominal CT exams displayed signs of enteric disease. Of the 45 patients studied with both CT and colonoscopy, 35 (78 %) had signs of intestinal disease by CT. Of these 35 patients, colonoscopic signs of an intestinal lesion were found in 29 and histologic proof of disease was established in 30 cases. Colonoscopy and histology detected 8 lesions missed by CT. There were 14 cases of unspecific colitis, 15 cases of cytomegalovirus (CMV) colitis, and 4 cases of enteric tuberculosis as per biopsy. Five patients presented with Kaposi`s sarcoma and 1 with a non-Hodgkin`s lymphoma. Neither colonoscopic nor CT signs of intestinal disease did reliably distinguish between histologic subgroups. Specifically, CMV colitis could not be distinguished from unspecific colitis. CD4{sup +} T-lymphocyte counts for histologic subgroups were not significantly different, either. No colonoscopic or histologic feature predicted survival, whereas low CD4 counts and ascites on CT indicated a poor prognosis. Whereas CT detects signs of intestinal disease in most AIDS patients, these signs remain largely unspecific. Colonoscopy and biopsies provide no consistently valid standard with which to compare CT because of controversial sensitivity and specificity of these methods. The CT technique detects small bowel as well as extraintestinal disease. Therefore, CT is an important diagnostic modality in abdominal disease of immunocompromised patients. (orig.) With 7 figs., 6 tabs., 30 refs.

  1. Preliminary development of the Active Colonoscopy Training Model

    Directory of Open Access Journals (Sweden)

    Choi J

    2011-06-01

    Full Text Available JungHun Choi1, Kale Ravindra1, Randolph Robert1, David Drozek21Mechanical Engineering, Ohio University, Athens, OH, USA; 2College of Osteopathic Medicine, Ohio University, Athens, OH, USAAbstract: Formal colonoscopy training requires a significant amount of time and effort. In particular, it requires actual patients for a realistic learning experience. The quality of colonoscopy training varies, and includes didactic courses and procedures proctored by skilled surgeons. A colonoscopy training model is occasionally used as part of the training method, but the effects are minute due to both the simple and tedious training procedures. To enhance the educational effect of the colonoscopy training model, the Active Colonoscopy Training Model (ACTM has been developed. ACTM is an interactive colonoscopy training device which can create the environment of a real colonoscopy procedure as closely as possible. It comprises a configurable rubber colon, a human torso, sensors, a display, and the control part. The ACTM provides audio and visual interaction to the trainee by monitoring important factors, such as forces caused by the distal tip and the shaft of the colonoscope and the pressure to open up the lumen and the localization of the distal tip. On the computer screen, the trainee can easily monitor the status of the colonoscopy, which includes the localization of the distal tip, maximum forces, pressure inside the colon, and surgery time. The forces between the rubber colon and the constraints inside the ACTM are measured and the real time display shows the results to the trainee. The pressure sensors will check the pressure at different parts of the colon. The real-time localized distal tip gives the colonoscopy trainee easier and more confident operation without introducing an additional device in the colonoscope. With the current need for colonoscopists and physicians, the ACTM can play an essential role resolving the problems of the current

  2. SU-E-J-114: Towards Integrated CT and Ultrasound Guided Radiation Therapy Using A Robotic Arm with Virtual Springs

    Energy Technology Data Exchange (ETDEWEB)

    Ding, K; Zhang, Y; Sen, H; Lediju Bell, M; Goldstein, S; Kazanzides, P; Iordachita, I; Wong, J [Johns Hopkins University, Baltimore, MD (United States)

    2014-06-01

    Purpose: Currently there is an urgent need in Radiation Therapy for noninvasive and nonionizing soft tissue target guidance such as localization before treatment and continuous monitoring during treatment. Ultrasound is a portable, low cost option that can be easily integrated with the LINAC room. We are developing a cooperatively controlled robot arm that has high intrafraction reproducibility with repositioning of the ultrasound probe. In this study, we introduce virtual springs (VS) to assist with interfraction probe repositioning and we compare the soft tissue deformation introduced by VS to the deformation that would exist without them. Methods: Three metal markers were surgically implanted in the kidney of one dog. The dog was anesthetized and immobilized supine in an alpha cradle. The reference ultrasound probe position and force to ideally visualize the kidney was defined by an experienced ultrasonographer using the Clarity ultrasound system and robot sensor. For each interfraction study, the dog was removed from the cradle and re-setup based on CBCT with bony anatomy alignment to mimic regular patient setup. The ultrasound probe was automatically returned to the reference position using the robot. To accommodate the soft tissue anatomy changes between each setup the operator used the VS feature to adjust the probe and obtain an ultrasound image that matched the reference image. CBCT images were acquired and each interfraction marker location was compared with the first interfraction Result. Results: Analysis of the marker positions revealed that the kidney was displaced by 18.8 ± 6.4 mm without VS and 19.9 ± 10.5 mm with VS. No statistically significant differences were found between two procedures. Conclusion: The VS feature is necessary to obtain matching ultrasound images, and they do not introduce further changes to the tissue deformation. Future work will focus on automatic VS based on ultrasound feedback. Supported in part by: NCI R01 CA161613

  3. Repeat colonoscopy after a colonoscopy with a negative result in Ontario: a population-based cohort study.

    Science.gov (United States)

    Hol, Lieke; Sutradhar, Rinku; Gu, Sumei; Baxter, Nancy N; Rabeneck, Linda; Tinmouth, Jill M; Paszat, Lawrence F

    2015-01-01

    Data suggest the overuse of repeat colonoscopies, especially in patients at low risk for colorectal cancer. Our objective was to evaluate the time to repeat colonoscopies in low-risk patients aged 50-79 years old and the associated patient- and endoscopist-related factors. All patients aged 50-79 years of age who underwent a complete outpatient colonoscopy with a negative result between 2000 and 2007 were identified from the Ontario Health Insurance Plan database. A colonoscopy performed within 5.5 years of follow-up after the index colonoscopy was considered an early repeat colonoscopy. Patient, endoscopist and endoscopy setting characteristics were recorded and their association with an early repeat colonoscopy was determined using an extended Cox proportional hazards regression model. The cohort consisted of 546 467 patients: 55.4% of the patients were female with a mean age of 61.1 years (95% confidence interval [CI] 61.1-61.2). The cumulative percentage of early repeat colonoscopy after 5.5 years was 33.7%. The rate decreased significantly between 2000 and 2007 (hazard ratio [HR] 0.35, 95% CI 0.34-0.36). General surgeons were associated with a higher risk of early repeat colonoscopy than gastroenterologists (HR 1.27, 95% CI 1.25-1.28). Endoscopists practising in a nonhospital setting were more likely to perform an early repeat colonoscopy (HR 1.26, 95% CI 1.22-1.30) than endoscopists at a hospital. This study showed that there was overuse of early repeat colonoscopy in more than 30% of patients who were at low risk for colorectal cancer. The risk decreased significantly between 2000 and 2007 but was still greater than 20% in 2007. Our findings can be used to develop targeted educational interventions among subgroups of endoscopists with a higher rate of early repeat colonoscopy.

  4. Good interrater reliability of a new grading system in detecting traumatic bone marrow lesions in the knee by dual energy CT virtual non-calcium images

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Jian-xin; Wang, Yi-min [Department of Radiology, Wuhan 161th Hospital, 68 Huangpu Road, Wuhan 430010 (China); Kong, Xiang-quan, E-mail: kxq2013@tom.com [Department of Radiology, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan 430022 (China); Yang, Cheng; Wang, Peng [Department of Radiology, Wuhan 161th Hospital, 68 Huangpu Road, Wuhan 430010 (China)

    2015-06-15

    Highlights: • We use DECT image to show traumatic bone marrow lesions (BMLs). • Traumatic BMLs were assessed with quantitative and qualitative analysis. • Time interval between CT scanning and MRI was only 1.8 ± 0.6 days. • All patients have no obviously fracture, and bone bruise was diagnosed. - Abstract: Objective: To evaluate the capacity of dual-energy computed tomography (DECT) virtual non-calcium (VNCa) images in detecting post-traumatic bone marrow lesions (BMLs) in the knee with a new grading system. Methods: DECT and magnetic resonance (MR) imaging were used to examine acute trauma of the knee in 32 patients. VNCa images were generated by dual-energy subtraction of calcium, and the lower end of the femur and upper end of the tibia each were divided into six regions for grading of bone marrow by two musculoskeletal radiologists using a four-grading system (Grade 4, very obvious lesions; Grade 3, relatively obvious lesions; Grade 2, slight or suspicious lesion on VNCa image and mild lesion on MR image; Grade 1, normal bone marrow). CT values were obtained in the BMLs. MR images were used as the reference standard. Grade 3–4 bone marrow was regarded as a positive result to evaluate the performance of VNCa images in detecting traumatic BMLs in the knee, and receiver operating characteristic (ROC) curve analysis of VNCa images for detection of knee BMLs was performed based on CT value of the bone marrow. Results: Bone marrow rating by the two radiologists showed very good consistency (κ = 0.850 and 0.869 for VNCa and MR images, respectively). VNCa and MR images had good consistency (κ = 0.799 for lower end of the femur; κ = 0.659 for upper end of the tibia). When Grade 3–4 bone marrow was regarded as a positive result, the sensitivity, specificity, positive predictive value, and negative predictive value of VNCa images for detection of BMLs in the lower end of the femur were 73.5%, 98.6%, 94.7%, and 91.6%, respectively, and the values in the

  5. 静脉膀胱造影64排螺旋CT扫描及仿真内镜成像技术探讨%CT virtual endoscopy of intravenous cystography

    Institute of Scientific and Technical Information of China (English)

    杨旭峰; 严超贵; 冯玉; 林锦江; 欧阳龙源; 林芝; 李子平; 孙灿辉

    2014-01-01

    目的探讨静脉膀胱造影膀胱CT扫描方法,提高膀胱CT仿真内镜图像质量。方法将94例膀胱检查患者分为三组:A组30例,盆腔增强扫描后,将尿液排完,再口服300 ml水,上检查床翻转两次后行膀胱扫描;B组32例,扫描同A组相同,但喝水量则根据扫描时所测膀胱充盈后的体积口服等量的水;C组32例,盆腔增强扫描后,不排尿,等候30 min,上检查床后反转两次后行膀胱扫描。测定膀胱腔内不同区域液体密度的CT值;对膀胱仿真内镜图像进行评分,统计分析结果。结果 A组和B组膀胱腔内不同区域所测CT值差别无统计学意义(P>0.05),显示膀胱内对比剂均匀性较好。C组膀胱腔内不同区域所测CT值差别有统计学意义(P0.05),A组与C组及B组与C组之间差异有统计学意义(P<0.001)。A组和B组图像明显优于C组。结论盆腔增强扫描后,将尿液排完,再口服300ml水,上检查床反转两次后行膀胱扫描,可获得良好的CT仿真内镜图像。%ObjectiveTo investigate the technique of CT virtual endoscopy of intravenous cystography.Methods Ninety-four patients were enrolled in the study. One group of 30 patients emptied the bladder completely after contrast-enhanced CT of the pelvis and then drank 300 ml of water to re-fill the bladder. Patients rolled over twice on the examining table before the CT virtual cystoscopy. The second group of 32 patients underwent the same procedure and the amount of water ingested was determined by the pre-void bladder volume. The third group of 32 patients underwent CT virtual cystoscopy 30 minutes after contrast-enhanced pelvic CT without emptying the bladder or drinking water. CT values were measured in different regions of the bladder lumen and the CT virtual cystoscopic images were scored. The results were compared among the 3 groups of patients.Results The intravesical CT values of the first 2 groups of patients

  6. CT colonography and cost-effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Mavranezouli, Ifigeneia [University College London, National Collaborating Centre for Mental Health, Centre for Outcomes Research and Effectiveness, Sub-department of Clinical Health Psychology, London (United Kingdom); East, James E. [St Marks Hospital, Imperial College London, Wolfson Unit for Endoscopy, London (United Kingdom); Taylor, Stuart A. [University College Hospital, Specialist X-Ray, London (United Kingdom); University College Hospital, Department of Imaging, London (United Kingdom)

    2008-11-15

    CT colonography (CTC) is increasingly advocated as an effective initial screening tool for colorectal cancer. Nowadays, policy-makers are increasingly interested in cost-effectiveness issues. A number of studies assessing the cost-effectiveness of CTC have been published to date. The majority of findings indicate that CTC is probably not cost-effective when colonoscopy is available, but this conclusion is sensitive to a number of key parameters. This review discusses the findings of these studies, and considers those factors which most influence final conclusions, notably intervention costs, compliance rates, effectiveness of colonoscopy, and the assumed prevalence and natural history of diminutive advanced polyps. (orig.)

  7. Patient satisfaction with colonoscopy: A literature review and pilot study

    Science.gov (United States)

    Chartier, Lucas; Arthurs, Erin; Sewitch, Maida J

    2009-01-01

    BACKGROUND: Current guidelines recommend that colonoscopic colorectal cancer screening be undertaken every 10 years after the age of 50 years. However, because the procedure does not meet criteria that promote screening uptake, patient satisfaction with colonoscopy may encourage repeat screening. OBJECTIVE: To systematically review the literature and conduct a pilot study of patient satisfaction with the colonoscopy experience. METHODS: All cohort studies from January 1997 to August 2008 in the MEDLINE database that measured either patient satisfaction with colonoscopy, patient willingness to return for colonoscopy under the same conditions or patient preference for colonoscopy compared with other large bowel procedures were identified. The search was supplemented by journal citation lists in the retrieved articles. RESULTS: Of the 29 studies identified, 15 met the inclusion criteria. Consistently, the vast majority of patients (approximately 95%) were very satisfied with their colonoscopy experience. Patient satisfaction was similar for screening and nonscreening colonoscopy. Patient willingness to return for the procedure ranged from 73% to 100%. Of the five studies that examined modality preference, three studies reported the majority of patients preferred colonography to colonoscopy and two studies reported the reverse. Our pilot study findings mirrored those of other studies that were conducted in the United States. The major limitation of the included studies was that patients who were most dissatisfied may have gone elsewhere to have their colonoscopy. CONCLUSIONS: Patients were very satisfied with colonoscopy. The majority were willing to return for repeat testing under the same conditions, and colonoscopy was not preferred over other modalities. However, studies were limited by methodological shortcomings. PMID:19319384

  8. Postprocessing techniques of CT colonography in detection of colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ming-Yue Luo; Hong Shan; Li-Qing Yao; Kang-Rong Zhou; Wen-Wei Liang

    2004-01-01

    AIM: To evaluate the value of postprocessing techniques of CT colonography, including multiplanar reformation (MPR),virtual colonoscopy (VC), shaded surface display (SSD) and Raysum, in detection of colorectal carcinomas.METHODS: Sixty-four patients with colorectal carcinoma underwent volume scanning with spiral CT. MPR, VC, SSD and Raysum images were obtained by using four kinds of postprocessing techniques in workstation. The results were comparatively analyzed according to circumferential extent,lesion length and pathology pattern of colorectal carcinomas.All diagnoses were proved pathologically and surgically.RESULTS: The accuracy of circumferential extent of colorectal carcinoma determined by MPR, VC, SSD and Raysum was 100.0%, 82.8%, 79.7% and 79.7%,respectively. There was a significant statistical difference between MPR and VC. The consistent rate of lesion length was 89.1%, 76.6%, 95.3% and 100.0%, respectively.There was a statistical difference between VC and SSD.The accuracy of discriminating pathology pattern was 81.3%,92.2%, 71.9% and 71.9%, respectively. There was a statistical difference between VC and SSD. MPR could determine accurately the circumference of colorectal carcinoma, Raysum could determine the length of lesion more precisely than SSD, VC was helpful in discriminating pathology patterns.CONCLUSION: MPR, VC, SSD and Raysum have advantage and disadvantage in detection of colorectal carcinoma, use of these methods in combination can disclose the lesion more accurately.

  9. Effective colonoscopy training techniques: strategies to improve patient outcomes.

    Science.gov (United States)

    Papanikolaou, Ioannis S; Karatzas, Pantelis S; Varytimiadis, Lazaros T; Tsigaridas, Athanasios; Galanopoulos, Michail; Viazis, Nikos; Karamanolis, Dimitrios G

    2016-01-01

    Colonoscopy has substantially evolved during the last 20 years and many different training techniques have been developed in order to improve the performance of endoscopists. The most known are mechanical simulators, virtual reality simulators, computer-simulating endoscopy, magnetic endoscopic imaging, and composite and explanted animal organ simulators. Current literature generally indicates that the use of simulators improves performance of endoscopists and enhances safety of patients, especially during the initial phase of training. Moreover, newer endoscopes and imaging techniques such as high-definition colonoscopes, chromocolonoscopy with dyes spraying, and third-eye retroscope have been incorporated in everyday practice, offering better visualization of the colon and detection of polyps. Despite the abundance of these different technological features, training devices are not widely used and no official guideline or specified training algorithm or technique for lower gastrointestinal endoscopy has been evolved. In this review, we present the most important training methods currently available and evaluate these using existing literature. We also try to propose a training algorithm for novice endoscopists.

  10. Medical image of the week: Boerhaave's syndrome during colonoscopy

    Directory of Open Access Journals (Sweden)

    Meenakshisundaram C

    2015-07-01

    Full Text Available No abstract available. Article truncated at 150 words. A 76-year-old woman with no significant past medical history underwent outpatient screening colonoscopy. The procedure was difficult due to a tortuous colon and only multiple diverticula were visualized. She vomited once during the procedure. In the immediate postoperative period, she complained of neck swelling. Her vital signs were stable. On examination, right sided neck and facial swelling with palpable crepitations were noticed as well as coarse breath sounds heard on auscultation of both lung fields. Immediate chest X-ray (Figure 1 was obtained which showed bilateral subcutaneous emphysema extending from the supraclavicular area and above to the neck. Subsequent thoracic CT scan showed extensive subcutaneous air within the soft tissues of the neck bilaterally, extending into the mediastinum and along the anterior chest wall (Figure 2. An esophagram (Figure 3 revealed a focus of oral contrast actively extravasating approximately at 2.5 cm above the gastro-esophageal junction consistent with a small perforation ...

  11. Helical CT in the diagnosis of acute lower gastrointestinal haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwal, Rohan [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Vladica, Philip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)]. E-mail: rpvl@imag.wsahs.nsw.gov.au; Chou, Roger [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Law, W. Phillip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)

    2006-05-15

    Introduction: A pilot study to evaluate helical computer tomography (CT) as a diagnostic tool for acute lower gastrointestinal tract (GIT) bleeding. CT was compared to conventional angiography (CA) and colonoscopy for the diagnosis and detection of bleeding site in suspected cases of acute lower GIT bleeding. Methods: Seven patients presenting with acute lower GIT bleeding, between June and November 2002, underwent CT examinations. All of these seven patients underwent CA following CT. Emergency colonoscopies were performed on five patients investigated with both CT and CA. Median delay from the most recent episode of hematochezia to CT was two and a half hours, to CA was 3 h, and to colonoscopy was 4 h. None of the patients underwent nuclear medicine (NM) bleeding studies. Results: Haemoglobin drop in all patients was greater than 15 g/L in the first 24 h of presentation. The mean age was 68.86 years (range, 49-83 years). Comparing CT and CA, there were four concordant and three discordant results. Both modalities had concordant findings of two active bleeding sites, one non-bleeding rectal tumour, and one negative case result. In three patients, the source of bleeding was found on CT whereas CA was negative. Emergency colonoscopies performed in all of these three patients confirmed blood in the colon/ileum. Conclusion: Early experience suggests that CT is a safe, convenient and accurate diagnostic tool for acute lower GIT haemorrhage. It raises questions regarding the sensitivity of CA. A new management algorithm for acute lower GIT haemorrhage using CT as the pre-CA screening tool is being proposed based on the preliminary findings. Positive CT will allow directed therapeutic angiography, while negative CT will triage patients into alternative management pathways.

  12. Automatic and unbiased assessment of competence in colonoscopy

    DEFF Research Database (Denmark)

    Preisler, Louise; Søndergaard Svendsen, Morten Bo; Søndergaard, Bo;

    2016-01-01

    Background and aims: Colonoscopy is a difficult procedure to master. Increasing demands for colonoscopy, due to screening and surveillance programs, have highlighted the need for competent performers. Valid methods for assessing technical skills are pivotal for training and assessment. This study...

  13. Recent advances in colonoscopy [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Thomas J.W. Lee

    2016-03-01

    Full Text Available Colonoscopy is an important and frequently performed procedure. It is effective in the prevention of colorectal cancer and is an important test in the investigation of many gastrointestinal symptoms. This review focuses on developments over the last 5 years that have led to changes in aspects of colonoscopy, including patient preparation, technical factors, therapeutic procedures, safety, and quality.

  14. Role of colonoscopy in patients with persistent acute diverticulitis

    Institute of Scientific and Technical Information of China (English)

    Adi Lahat; Henit Yanai; Emad Sakhnini; Yoram Menachem; Simon Bar-Meir

    2008-01-01

    AIM:To identify patients with persistent acute diverticulitis who might benefit from an early colonoscopy during their first hospitalization.METHODS:All patients hospitalized between July 2000 and December 2006 for acute diverticulitis who underwent colonoscopy were included in the study.Patients were followed during hospitalization and after discharge.Patients were considered to have a persistent course of acute diverticulitis if symptoms continued after 1 wk of conventional treatment with IV antibiotics,or if symptoms recurred within 2 mo after discharge.Patients were considered to benefit from an early colonoscopy if the colonoscopy was therapeutic or if it changed a patient's outcome.RESULTS:Three hundred and six patients were hospitalized between July 2000 and December 2006 with the diagnosis of acute diverticulitis.Two hundred and twenty four of these were included in the study group.Twenty three patients (10.3%) fulfilled the criteria for a persistent course of acute diverticulitis.Of them,four patients (17.4%) clearly benefited from an early colonoscopy;these patients' clinical course is described.None of the patients with a regular non-persistent course demonstrated any benefit from colonoscopy.CONCLUSION:Early colonoscopy detected other significant pathology,which accounted for the clinical presentation in 17% of patients with persistent acute diverticulitis.Therefore,we believe an early colonoscopy should be considered in all patients with a persistent clinical course.

  15. Colonoscopy training for nurse endoscopists : A feasibility study

    NARCIS (Netherlands)

    Koornstra, Jan J.; Corporaal, Sietske; Giezen-Beintema, Wiesje M.; de Vries, Sietske E.; van Dullemen, Hendrik M.

    2009-01-01

    Background: Screening by using colonoscopy is recommended in many countries to reduce the risk of death from colorectal cancer. Given the limited supply of medical endoscopists, nurse endoscopists may represent an economic alternative. Objective: To develop a colonoscopy training program for nurse e

  16. Improving the Quality of Color Colonoscopy Videos

    Directory of Open Access Journals (Sweden)

    Dahyot Rozenn

    2008-01-01

    Full Text Available Abstract Colonoscopy is currently one of the best methods to detect colorectal cancer. Nowadays, one of the widely used colonoscopes has a monochrome chipset recording successively at 60 Hz and components merged into one color video stream. Misalignments of the channels occur each time the camera moves, and this artefact impedes both online visual inspection by doctors and offline computer analysis of the image data. We propose to restore this artefact by first equalizing the color channels and then performing a robust camera motion estimation and compensation.

  17. Reduction of dental filling metallic artifacts in CT-based attenuation correction of PET data using weighted virtual sinograms optimized by a genetic algorithm

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Ay, Mohammad Reza; Ahmadian, Alireza; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2010-01-01

    Purpose: The presence of metallic dental fillings is prevalent in head and neck PET/CT imaging and generates bright and dark streaking artifacts in reconstructed CT images. The resulting artifacts would propagate to the corresponding PET images following CT-based attenuation correction (CTAC). This

  18. Clough-Tocher interpolation of virtual sinogram in a Delaunay triangulated grid for metal artifact reduction of PET/CT images

    NARCIS (Netherlands)

    Abdoli, M.; de Long, J. R.; Pruim, J.; Dierckx, R. A. J. O.; Zaidi, H.

    2011-01-01

    Metallic implants, such as hip implants, are known to induce streaking artifacts in CT images which can cause over/underestimation of the activity uptake in CT-based attenuation corrected PET images. Hence, metal artifact reduction (MAR) of CT images is essential in order to obtain accurate quantifi

  19. Effect Supermint oil (Peppermint oil on children's pain during Colonoscopy

    Directory of Open Access Journals (Sweden)

    M Najafi

    2014-04-01

    Full Text Available Introduction: Pain during colonoscopy, especially in children, including the challenges faced by the medical team. The aim of study was investigation the analgesic effect Supermint oil (peppermint oil on pain in children during colonoscopy. Methods and Materials: In this clinical trial study, 101 children (7-14 years old candidate colonoscopy were randomly divided into two groups, respectively. About half an hour before the colonoscopy case group (n=51 was administrated oral drops Supermint oil (peppermint oil. Patients were filled a pediatric pain questionnaire. In control group (n=50 filled a questionnaire without any administration. Data were analyzed using SPSS version 11.5 and (T-test and Paired sample t-test, Corraletion,Man withney. Results: Mean value of pain, duration of colonoscopy in control group was 5/60+1/85 and in case group was 4/20+1/70 and this diference was significant (P

  20. Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ji Young; Ro, Hee Jeong; Choi, Jung Bin; Chung, Ji Eun; Kim, Yong Jin; Suh, Won Hyuck; Lee, Jong Kyun [Song-Do Hospital, Seoul (Korea, Republic of); Park, Jong Beom [East- West Neo Medical Center, Kyung Hee University, Seoul (Korea, Republic of)

    2007-12-15

    To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions.

  1. [Pediatric colonoscopy at the University Hospital of Cocody (Ivory Coast)].

    Science.gov (United States)

    Okon, J B; Assi, C; Diakité, M; Siaka, K; Ouattara, A; Soro, D; Coulibaly, A; Lohouès, M J; Camara, B M

    2012-01-01

    No published data are available on pediatric colonoscopy in Ivory Coast (and only one report on pediatric gastroscopy). We conducted a retrospective study of all colonoscopy reports of procedures performed from 1 September, 1991, to December 31, 2010, at the University Hospital of Cocody in Abidjan (Ivory Coast) and examined the epidemiological aspects, conditions of performance, indications, and results of colonoscopy in patients younger than 18 years. Eleven of the total of 1 159 colonoscopies were performed in in this age group (0.94%). The mean age of these 8 girls and 3 boys was 15 years (range: 10 to 17 years). All patients had been referred by a gastroenterologist. Bowel preparation was performed in all with a water enema. Premedication was performed exclusively with midazolam. A pediatric colonoscope was used. The colonoscopy was incomplete in 36% of cases (n=4). Rectal bleeding was the main indication. Results were abnormal in 72% of cases (n=8) and the lesions found were juvenile polyps, ulcerative colitis, sigmoid varices, rectocolitis due to a caustic product, and adenomatous polyps. The results of the examination were normal in 3 children. No complications were reported. In conclusion, although the pediatric colonoscopy practice at the University Hospital of Cocody in Abidjan is extremely small, its therapeutic and diagnostic yields are high, particularly in cases of rectal bleeding. Physicians (general practitioners and pediatricians) managing children should not hesitate to ask for a colonoscopy when appropriate.

  2. Standard forward-viewing colonoscopy versus full-spectrum endoscopy: an international, multicentre, randomised, tandem colonoscopy trial

    Science.gov (United States)

    Gralnek, Ian M.; Siersema, Peter D.; Halpern, Zamir; Segol, Ori; Melhem, Alaa; Suissa, Alain; Santo, Erwin; Sloyer, Alan; Fenster, Jay; Moons, Leon M. G.; Dik, Vincent K.; D’Agostino, Ralph B.; Rex, Douglas K.

    2014-01-01

    Summary Background Although colonoscopy is the accepted standard for detection of colorectal adenomas and cancers, many adenomas and some cancers are missed. To avoid interval colorectal cancer, the adenoma miss rate of colonoscopy needs to be reduced by improvement of colonoscopy technique and imaging capability. We aimed to compare the adenoma miss rates of full-spectrum endoscopy colonoscopy with those of standard forward-viewing colonoscopy. Methods We did an international, multicentre, randomised trial at three sites in Israel, one site in the Netherlands, and two sites in the USA between Feb 1, 2012, and March 31, 2013. Patients aged 18–70 years referred for colorectal cancer screening, polyp surveillance, or diagnostic assessment underwent same-day, back-to-back tandem colonoscopy with standard forward-viewing colonoscope and the full-spectrum endoscopy colonoscope. The patients were randomly assigned (1:1), via computer-generated randomisation with block size of 20, to which procedure was done first. The endoscopist was masked to group allocation until immediately before the start of colonoscopy examinations; patients were not masked. The primary endpoint was adenoma miss rates. We did per-protocol analyses. This trial is registered with ClinicalTrials.gov, number NCT01549535. Findings 197 participants were enrolled. 185 participants were included in the per-protocol analyses: 88 (48%) were randomly assigned to receive standard forward-viewing colonoscopy first, and 97 (52%) to receive full-spectrum endoscopy colonoscopy first. By per-lesion analysis, the adenoma miss rate was significantly lower in patients in the full-spectrum endoscopy group than in those in the standard forward-viewing procedure group: five (7%) of 67 vs 20 (41%) of 49 adenomas were missed (p<0·0001). Standard forward-viewing colonoscopy missed 20 adenomas in 15 patients; of those, three (15%) were advanced adenomas. Full-spectrum endoscopy missed five adenomas in five patients in

  3. Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

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    Mingyue Luo

    Full Text Available To evaluate the diagnostic value of multidetector CT (MDCT and its multiplanar reformation (MPR, volume rendering (VR and virtual bronchoscopy (VB postprocessing techniques for primary trachea and main bronchus tumors.Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology.Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6, tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16, extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1, longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1, morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1 and extents (mild, n = 5; moderate, n = 7; severe, n = 19, distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10, and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density

  4. Location of colorectal cancer: colonoscopy versus surgery. Yield of colonoscopy in predicting actual location.

    Science.gov (United States)

    Blum-Guzman, Juan Pablo; Wanderley de Melo, Silvio

    2017-07-01

     Recent studies suggest that differences in biological characteristics and risk factors across cancer site within the colon and rectum may translate to differences in survival. It can be challenging at times to determine the precise anatomical location of a lesion with a luminal view during colonoscopy. The aim of this study is to determine if there is a significant difference between the location of colorectal cancers described by gastroenterologists in colonoscopies and the actual anatomical location noted on operative and pathology reports after colon surgery.  A single-center retrospective analysis of colonoscopies of patient with reported colonic masses from January 2005 to April 2014 (n = 380) was carried. Assessed data included demography, operative and pathology reports. Findings were compared: between the location of colorectal cancers described by gastroenterologists in colonoscopies and the actual anatomical location noted on operative reports or pathology samples.  We identified 380 colonic masses, 158 were confirmed adenocarcinomas. Of these 123 underwent surgical resection, 27 had to be excluded since no specific location was reported on their operative or pathology report. An absolute difference between endoscopic and surgical location was found in 32 cases (33 %). Of these, 22 (23 %) differed by 1 colonic segment, 8 (8 %) differed by 2 colonic segments and 2 (2 %) differed by 3 colonic segments.  There is a significant difference between the location of colorectal cancers reported by gastroenterologists during endoscopy and the actual anatomical location noted on operative or pathology reports after colon surgery. Endoscopic tattooing should be used when faced with any luminal lesions of interest.

  5. Automatic and unbiased assessment of competence in colonoscopy

    DEFF Research Database (Denmark)

    Preisler, Louise; Svendsen, Morten Bo Søndergaard; Søndergaard, Bo

    2016-01-01

    . The Generalizability coefficient (G-coefficient) was 0.80, and a Decision-study (D-study) revealed that four recordings were sufficient to ensure a G-coefficient above 0.80. We showed a positive correlation between CoPS and experience with Pearson's r of 0.61 (P ... is the first clinical descriptive report of a novel colonoscopy assessment tool based on Magnetic Endoscopic Imaging (MEI) data and the aim was to gather validity evidence based on the data collected using the "Colonoscopy Progression Score" (CoPS). Methods: We recorded 137 colonoscopy procedures performed...

  6. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  7. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    NARCIS (Netherlands)

    Abdoli, Mehrsima; de Jong, Johan R.; Pruim, Jan; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2011-01-01

    Purpose Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over-or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron

  8. Study: Colonoscopy After 75 May Not Be Worth It

    Science.gov (United States)

    ... Study: Colonoscopy After 75 May Not Be Worth It But, expert says age shouldn't be only ... and remove cancerous growths in the colon, but it may not provide much cancer prevention benefit after ...

  9. Audit of colonoscopy practice in Lagos University Teaching Hospital

    Directory of Open Access Journals (Sweden)

    Adedapo Osinowo

    2016-01-01

    Full Text Available Introduction: Recent procurement of new endoscopies and accessories led to the reactivation of diagnostic and therapeutic colonoscopy services at our center. A preliminary audit is deemed necessary after a 2-year period of open access colonoscopy. Objective: To assess the pattern of indications, diagnostic yield, and selected key performance indicators in the practice of colonoscopy at our tertiary hospital. Patients and Methods: The endoscopy reports of all patients that underwent colonoscopy from January 2012 to April 2014 were reviewed. The demographic data, indications, and endoscopic findings were recorded. Information on cecal intubation, colonoscopy withdrawal time, polyp detection, adverse events, and bowel preparation quality were also extracted and analyzed. Results: Colonoscopy was performed in 149 patients. They were 81 males and 68 females, aged between 18 and 101 years with a mean of 46.9 ± 22.7 years. 126 (84.5% patients had a colonoscopy for symptomatic conditions while 5 (4% were for screening. Bowel preparation was assessed to be excellent in 81 (54.4%, adequate in 42 (28.2%, and inadequate in 26 (17.4% patients, respectively. The cecal intubation rate (CIR was 80.2%, polyp detection rate 7.4%, average colonoscopy withdrawal time was 6 min 53 s, overall diagnostic yield 55.9% and there were no adverse events. Tumors were seen in 19 patients (10.1%; 13 were located in the rectum, three in the sigmoid and three in the descending colon. Conclusion: The audit revealed that our CIR could be improved by a more effective bowel preparation, increased expertise, and procedure volume of endoscopists. Tumors of the colorectum were detected in 10.1% of patients.

  10. Colonoscopy Practice in Lagos, Nigeria: A Report of an Audit

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    C. A. Onyekwere

    2013-01-01

    Full Text Available Background. Colonoscopy effectiveness depends on the quality of the examination. Community-based report of quality of colonoscopy practice in a developing country will help in determining standard and also serve as a stimulus for improvement in service. Aim. To review the quality of colonoscopy practice and document pattern of colonic disease including polyp detection rate in Lagos, Nigeria. Method. A protocol that captured the patients’ demographics, indication, and some quality indices of colonoscopy was developed and sent to all the identified colonoscopy units in Lagos to complete for all procedures performed between January 2011 and June 2012. All data were collated and analyzed. The quality indices studied were compared with guideline standard. Results. Twelve colonoscopy centers were identified but only nine centers responded. The gastroenterologist/endoscopists were physicians (3 and surgeons (5. Six hundred and seven colonoscopy procedures were performed during this period (M : F = 333 : 179 while the sex was not disclosed in 95 subjects. The examination indications were lower GI bleeding (24.2%, altered bowel habits (9.2%, lower abdominal pain (9.1%, screening for CRC (4.3% and unspecified (46.8%. Conscious sedation was generally used while bowel preparation (good in 81.4% was done with low residue diet and stimulant laxatives. Caecal intubation rate was 81.2%. Common endoscopic findings were haemorrhoids (43.2%, polyps/masses (13.4%, diverticulosis (11.1%, and no abnormality (23.4%. Polyp was detected in 6.8% of cases. Conclusion. Colonoscopy utilization is low, and the quality of practice is suboptimal; although limited resources could partly explain this, however it is not clear if the low rate of polyp detection is due to missed lesions or low population incidence.

  11. Appropriateness of colonoscopy: Diagnostic yield and safety in guidelines

    Institute of Scientific and Technical Information of China (English)

    Mario Grassini; Carlo Verna; Paolo Niola; Monica Navino; Edda Battaglia; Gabrio Bassotti

    2007-01-01

    AIM:To evaluate if the guidelines for the appropriateness of performing colonoscopy by American Society for Gastrointestinal Endoscopy (AGSE) and Italian Society of Digestive Endoscopy (SIED) yield a good diagnostic efficacy and do not present risks of missing important colonic pathologies in an Italian population sample.METHODS:A total of 1017 consecutive patients (560 men and 457 women; mean age 64.4 ± 16 years)referred to an open-access endoscopy unit for colonoscopy from July 2004 to May 2006 were evaluated according to ASGE and SIED guidelines for appropriateness of performing the procedure. Diagnostic yield was defined as the percentage of relevant colonic pathologies of the total number of colonoscopies performed.RESULTS:About 85.2% patients underwent colonoscopy that was considered appropriate based on at least one ASGE or SIED criterion,while it was considered inappropriate for 14.8% of patients. The diagnostic yield of colonoscopy was significantly higher for appropriate colonoscopies (26.94% vs 10.6%,P<0.001) than for inappropriate colonoscopies (5.3%). There was no missed colorectal cancer following the ASGE/SIED criteria.CONCLUSION:ASGE/SIED guidelines have shown a good diagnostic yield and the rate of missing relevant colonic pathologies seems very low. Unfortunately,the percentage of inappropriate referrals for colonoscopy in an open-access endoscopy system is still high,despite the number of papers published on the issue and the definition of international guidelines. Further steps are required to update and standardize the guidelines toincrease their diffusion and to promote educational programs for general practitioners.

  12. Image Retrieval Method for Multiscale Objects from Optical Colonoscopy Images

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    Hirokazu Nosato

    2017-01-01

    Full Text Available Optical colonoscopy is the most common approach to diagnosing bowel diseases through direct colon and rectum inspections. Periodic optical colonoscopy examinations are particularly important for detecting cancers at early stages while still treatable. However, diagnostic accuracy is highly dependent on both the experience and knowledge of the medical doctor. Moreover, it is extremely difficult, even for specialist doctors, to detect the early stages of cancer when obscured by inflammations of the colonic mucosa due to intractable inflammatory bowel diseases, such as ulcerative colitis. Thus, to assist the UC diagnosis, it is necessary to develop a new technology that can retrieve similar cases of diagnostic target image from cases in the past that stored the diagnosed images with various symptoms of colonic mucosa. In order to assist diagnoses with optical colonoscopy, this paper proposes a retrieval method for colonoscopy images that can cope with multiscale objects. The proposed method can retrieve similar colonoscopy images despite varying visible sizes of the target objects. Through three experiments conducted with real clinical colonoscopy images, we demonstrate that the method is able to retrieve objects of any visible size and any location at a high level of accuracy.

  13. Clostridium Difficile, Colitis, and Colonoscopy: Pediatric Perspective.

    Science.gov (United States)

    McConnie, Randolph; Kastl, Arthur

    2017-08-01

    Review tests available for detection of Clostridium difficile (C. Diff) induced disease, including when such tests should be done in children and how they should be interpreted. Multiple tests are available for detecting disease due to C. diff. These include colonoscopy and stool analysis. Colonoscopy with biopsy is the most sensitive test for detecting the presence of colitis. The toxins produced by the C. diff. (toxin A, toxin B, and binary toxin) are the agents that cause injury and disease. Only toxin producing C. diff. Strains will cause disease. Binary toxin by itself is not thought to produce disease. Binary toxin causes disease in humans when present with toxin A and B producing bacteria, and has been implicated with fulminant life threatening disease. Stool analyses vary in sensitivity and specificity depending on the assay used. The presence of toxin producing strains of C diff. in the stool does not equate with disease. The presence of a toxin-producing bacteria or toxins (A or B) only equates with disease if diarrhea or a diseased colon (toxic megacolon, ileus, and sepsis) is present. Nucleic acid amplification testing (NAAT), when used in the stool from patients with diarrhea, appears to be the most efficient study to detect the gene that encodes for toxin A and B and thus to diagnose C. diff.-induced disease. Infants have a high carriage rate of C. diff. and are believed not to develop disease from it or its toxins. Infants should not be tested for C. difficile. The NAAT is most specific when done on patients with diarrhea with liquid stools. Testing for C. difficile should only be done on patients with diarrhea. One can assume that a patient who has no diarrhea and is not ill does not have C. diff.-induced disease. Treatment should be limited to patients with diarrhea who test positive for C. diff. toxin (A or B) or toxin-producing bacteria. Direct testing for binary toxin is not commercially available. Binary toxin is only thought to cause disease

  14. Colonoscopy does not induce small intestinal bacterial overgrowth

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    Ioana Gabriela Moraru

    2017-01-01

    Full Text Available Background and Aim: Small intestinal bacterial overgrowth (SIBO is associated with gastrointestinal pathology and colonoscopy. This endoscopic investigation could cause changes in gut flora including the occurrence of SIBO. We looked in this study for the effect of colonoscopy (preparation and intubation on the occurrence of SIBO. Materials and Methods: Prospective study including thirty patients with irritable bowel syndrome (IBS diagnosed according to Rome III criteria. Two groups were designed: Twenty IBS patients that performed colonoscopy (G1 and ten IBS patients (G2 not referred to colonoscopy. All patients have been tested for the presence of SIBO using glucose hydrogen breath tests (GHBT at the beginning of the study, on day 1. G1 patients have also been tested before colonoscopy (day 2 and 1 week after (day 9. G2 patients performed GHBT on day 1 and on day 9. Results: The peak value of expired H2 was assessed, and the mean value was calculated. There were no significant statistical differences between the mean H2 values in the 2 groups of patients on day 1. The mean level of H2 significantly decreased after preparing for colonoscopy in G1 patients (P < 0.0001. There were no significant statistical differences between the mean levels of H2 on day 2 versus day 9 in G1 patients (P = 0.176. The mean level of H2 1 week after performing colonoscopy (7.65 ppm is higher than that obtained after preparing for it (6.3 ppm, but no statistical significance. Patients from G2 showed no statistical differences between the mean levels of H2 on day 1 versus day 9 (P = 0.6132. Patients in G1 had a significantly lower mean H2 level versus G2 patients on day 9. Conclusions: Colonoscopy does not produce SIBO. Preparing for colonoscopy influences the level of expired H2, it reduces the number of intestinal bacteria, probably trough a mechanic effect or by inflating air during the procedure. Performing GHBT too soon after colonoscopy might result in false

  15. Patients' perception of colonoscopy: patients with inflammatory bowel disease and irritable bowel syndrome experience the largest burden

    NARCIS (Netherlands)

    Denters, M.J.; Schreuder, M.; Depla, A.C.; Mallant-Hent, R.C.; Kouwen, M.C.A. van; Deutekom, M.; Bossuyt, P.M.; Fockens, P.; Dekker, E. den

    2013-01-01

    BACKGROUND: Colonoscopy is a frequently performed procedure worldwide with a negative perception, leading to reluctance to undergo the procedure. Perceptions could differ depending on the specific indication for the colonoscopy. AIMS: To compare patient satisfaction with the colonoscopy procedure be

  16. Patients' perception of colonoscopy: patients with inflammatory bowel disease and irritable bowel syndrome experience the largest burden

    NARCIS (Netherlands)

    Denters, M.J.; Schreuder, M.; Depla, A.C.; Mallant-Hent, R.C.; Kouwen, M.C.A. van; Deutekom, M.; Bossuyt, P.M.; Fockens, P.; Dekker, E. den

    2013-01-01

    BACKGROUND: Colonoscopy is a frequently performed procedure worldwide with a negative perception, leading to reluctance to undergo the procedure. Perceptions could differ depending on the specific indication for the colonoscopy. AIMS: To compare patient satisfaction with the colonoscopy procedure be

  17. Factors influencing quality of bowel preparation for colonoscopy.

    Science.gov (United States)

    Romero, Ronald V; Mahadeva, Sanjiv

    2013-02-16

    Recent technological advances in colonoscopy have led to improvements in both image enhancement and procedural performance. However, the utility of these technological advancements remain dependent on the quality of bowel preparation during colonoscopy. Poor bowel preparation has been shown to be associated with lower quality indicators of colonoscopy performance, such as reduced cecal intubation rates, increased patient discomfort and lower adenoma detection. The most popular bowel preparation regimes currently used are based on either Polyethylene glycol-electrolyte, a non-absorbable solution, or aqueous sodium phosphate, a low-volume hyperosmotic solution. Statements from various international societies and several reviews have suggested that the efficacy of bowel preparation regimes based on both purgatives are similar, although patients' compliance with these regimes may differ somewhat. Many studies have now shown that factors other than the type of bowel preparation regime used, can influence the quality of bowel preparation among adult patients undergoing colonoscopy. These factors can be broadly categorized as either patient-related or procedure-related. Studies from both Asia and the West have identified patient-related factors such as an increased age, male gender, presence of co-morbidity and socio-economic status of patients to be associated with poor bowel preparation among adults undergoing routine out-patient colonoscopy. Additionally, procedure-related factors such as adherence to bowel preparation instructions, timing of bowel purgative administration and appointment waiting times for colonoscopy are recognized to influence the quality of colon cleansing. Knowledge of these factors should aid clinicians in modifying bowel preparation regimes accordingly, such that the quality of colonoscopy performance and delivery of service to patients can be optimised.

  18. Screening colonoscopy tests in acromegaly patients – authors’ observations

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    Joanna Elżbieta Malicka

    2016-09-01

    Full Text Available Background . The prevalence of adenomas which cause acromegaly is estimated at 50–70 mln people. They secrete excess of growth hormone and increase the risk of benign and malignant tumours. Intestinal tumours are considered the most common types of lesion. In order to diagnose them early, a colonoscopic examination should be performed every 2–3 years. Objectives. The aim of the study was to estimate the frequency of the performed colonoscopies in acromegaly patients, and to assess their applicability in the detection of neoplastic lesions of the colon. Material and methods . The study involved 69 patients with acromegaly (26 M, 43 F, aged 26–83 years (mean 58.9 ± 11.0. The authors analyzed medical records and the results of additional tests. Results . Colonoscopy was performed in 30 patients (43.5% of cases, was well tolerated and without serious complications. 70% of colonoscopies revealed polyps of the colon and 6.7% revealed colon carcinoma. In 9 patients (30% of conducted studies colonoscopy examination showed no pathological changes. Only in 4 cases the test was performed more than once. Conclusions . Current recommendations regarding colonoscopic examinations in all acromegaly patients are implemented in less than half of the cases. Recommendations relating to colonoscopy being repeated every 2–3 years are followed occasionally. Colonoscopy is a diagnostic test of great significance. In 70% of cases it enables the detection and removal of pathological lesions of the colon. As a low-invasive, safe and well-tolerated examination it should be performed in all patients. GPs should make acromegaly patients aware of the importance of colonoscopy and refer them for periodic follow-up examinations.

  19. Applying microCT and 3D Visualization to Jurassic Silicified Conifer Seed Cones: A Virtual Advantage Over Thin-Sectioning

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    Carole T. Gee

    2013-11-01

    Full Text Available Premise of the study: As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT integrated with scientific visualization, three-dimensional (3D image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. Methods: MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. Results: If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. Conclusions: This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction.

  20. Noise-optimized virtual monoenergetic images and iodine maps for the detection of venous thrombosis in second-generation dual-energy CT (DECT): an ex vivo phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, Malte N.; Schabel, Christoph; Tsiflikas, Ilias; Ketelsen, Dominik; Mangold, Stefanie; Claussen, Claus D.; Nikolaou, Konstantin; Thomas, Christoph [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Krauss, Bernhard [Siemens AG, Healthcare Sector, Forchheim (Germany)

    2015-06-01

    Deep venous thrombosis (DVT) can be difficult to detect using CT due to poor and heterogeneous contrast. Dual-energy CT (DECT) allows iodine contrast optimization using noise-optimized monoenergetic extrapolations (MEIs) and iodine maps (IMs). Our aim was to assess whether MEI and IM could improve the delineation of thrombotic material within iodine-enhanced blood compared to single-energy CT (SECT). Six vessel phantoms, including human thrombus and contrast media-enhanced blood and one phantom without contrast, were placed in an attenuation phantom and scanned with DECT 100/140 kV and SECT 120 kV. IM, virtual non-contrast images (VNC), mixed images, and MEI were calculated. Attenuation of thrombi and blood were measured. Contrast and contrast-to-noise-ratios (CNRs) were calculated and compared among IM, VNC, mixed images, MEI, and SECT using paired t tests. MEI40keV and IM showed significantly higher contrast and CNR than SE120kV from high to intermediate iodine concentrations (contrast:pMEI40keV < 0.002,pIM < 0.005;CNR:pMEI40keV < 0.002,pIM < 0.004). At low iodine concentrations, MEI190keV and VNC images showed significantly higher contrast and CNR than SE120kV with inverted contrasts (contrast:pMEI190keV < 0.008,pVNC < 0.002;CNR:pMEI190keV < 0.003,pVNC < 0.002). Noise-optimized MEI and IM provide significantly higher contrast and CNR in the delineation of thrombosis compared to SECT, which may facilitate the detection of DVT in difficult cases. circle Poor contrast makes it difficult to detect thrombosis in CT. (orig.)

  1. 胶囊内镜联合仿真内窥镜在不明原因消化道出血中的应用%Capsule endoscopy combined with CT virtual endoscopy in obscure gastrointestinal bleeding

    Institute of Scientific and Technical Information of China (English)

    牛思; 李修岭; 葛英辉; 梁宝松; 李晓芳

    2013-01-01

    Objective To explore the value of application capsule endoscopy(capsule endoscopy,CE)combined with CT virtual endoscopy(CT virtual endoscopy,CTVE.) in the obscure gastrointestinal bleeding(OGIB).Methods Totally 21 patients with OGIB had been examinationed with CE and CTVE,to analyze the value of the two methods in OGIB.Results The lession has been found in 19 cases,including seven cases of small intestinal stromal tumors,three cases of inflammation,one case of granuloma,one case of small intestine,one case of vascular malformations,one case of metastases,two cases of small bowel diverticula,one case of bowel malformation,one case of Dieulafoy ulcer,one case of colon,one case of hookworm.The matching rate of the two methods is 81.0%.Conclusion CE combined with CTVE have high value of application in the diagnosis of the obscure gastrointestinal bleeding.%目的 探讨胶囊内镜(capsule endoscopy,CE)联合仿真内窥镜(CT virtual endoscopy,CTVE)在不明原因消化道出血(obscure gastrointestinal bleeding OGIB)中的应用价值.方法 对21例因不明原因消化道出血的患者同时行CE及CTVE检查分析两者联合在不明原因消化道出血的应用价值.结果 共有19例患者发现了病变,其中小肠间质瘤7例,炎症3例,肉芽肿1例,小肠血管畸形1例,转移瘤1例,小肠憩室2例,肠管畸形1例,Dieulafoy溃疡1例,结肠癌1例,钩虫病1例;两者吻合率81.0%.结论 CE联合CTVE在不明原因消化道出血中有较高的应用价值.

  2. [A case of gallstone ileus treated with electrohydraulic lithotripsy guided by colonoscopy].

    Science.gov (United States)

    Shin, Kyung Hwa; Kim, Dong Uk; Choi, Moon Gi; Kim, Won Jin; Ryu, Dong Yup; Lee, Bong Eun; Kim, Gwang Ha; Song, Geun Am

    2011-02-01

    A 63-year-old woman was admitted to the hospital with abdominal pain and nausea. Her abdomen was distended with obstructive bowel sounds on exam. There was diffuse abdominal tenderness but no palpable masses. Abdominal computed tomography (CT) scan revealed a large gallstone in the ileum. Surgical intervention was deferred given patient's known significant liver cirrhosis (Child-Pugh class B). Instead colonoscopy was performed and a large gallstone was found to be impacted at the ileocecal valve. The gallstone was fragmented using electrohydraulic lithotripsy (EHL) and then retrieved with snare and forceps. The patient made a full recovery and was eventually discharged home. This is the first reported case of an impacted gallstone at the ileocecal valve with successful colonoscopic treatment using electrohydraulic lithotripsy in Korea. This case highlights the potential therapeutic benefits for colonscopic retrieval of a gallstone impacted at the ileocecal valve in well selected individuals.

  3. Three-dimensional CT imaging and virtual endoscopy for the placement of self-expandable stents in oesophageal and tracheobronchial neoplastic stenoses.

    Science.gov (United States)

    Di Simone, M P; Mattioli, S; D'Ovidio, F; Bassi, F

    2003-01-01

    We examined the value of multislice computed tomography (CT) with three-dimensional (3D) reconstruction of the images as a pre-treatment examination in order to plan endoluminal stenting in 14 patients with large tumours involving the oesophagus and/or the tracheobronchial tree. The measurement of the stenosis obtained during 3D reconstruction of the CT images corresponded to that obtained by endoscopy and to the prosthesis chosen in all cases, with the exception of one patient undergoing double stenting due to inadequate gaseous distension of the oesophageal lumen. 3D CT may add information with respect to axial imaging, and be helpful to better plan and perform stenting of the oesophagus and airways without burdening the preoperative work-up.

  4. Ileoscopy in 39 hematochezia patients with normal colonoscopy

    Institute of Scientific and Technical Information of China (English)

    SP Misra; M Dwivedi; V Misra

    2006-01-01

    AIM: To assess the role of retrograde terminal ileoscopy in hematochezia patients with normal colonoscopy.METHODS: Between January 1997 and March 2005,39 hematochezia patients (males 36, females 3, mean age 44.7 years) with a reported normal colonoscopy underwent a repeat colonoscopy. After reaching the cecum, attempt was made to localize the ileocecal valve and intubate the terminal ileum. Any abnormality in the mucosa of the terminal ileum was carefully recorded and biopsies were obtained from suspiciouslooking lesions.RESULTS: During the study period there were 39 patients admitted for hematochezia in whom colonoscopy till cecum did not reveal any abnormality. Fulllength colonoscopy till the cecum could be performed in all the patients. The terminal ileum could be intubated in 36 patients. No abnormality was noted in 31 patients. Ileal ulcers were noted in two patients.Nodularity along with ulceration of the ileal mucosa, a Dieulafoy's lesion, and an angiomatous malformation were noted in one patient each. Histological examination of the biopsies obtained from the ulcers revealed typical tuberculous lesion in the patient with nodularity and ulceration. One of the patients had typhoid ulcers and another had non-specific ulcers.CONCLUSION: Retrograde terminal ileoscopy gives limited but valuable information, in patients with hematochezia and should be attempted in all such patients.

  5. Quality indicators for colonoscopy: Current insights and caveats

    Institute of Scientific and Technical Information of China (English)

    Hendrikus; JM; Pullens; Peter; D; Siersema

    2014-01-01

    Colonoscopy is the diagnostic modality of choice for investigation of symptoms suspected to be related to the colon and for the detection of polyps and colorectal cancer(CRC). Colonoscopy with removal of detected polyps has been shown to reduce the incidence and mortality of subsequent CRC. In many countries, population screening programs for CRC have been initiated, either by selection of patients for colonoscopy with fecal occult blood testing or by offering colonoscopy directly to average-risk individuals. Several endoscopy societies have formulated quality indicators for colonoscopy. These quality indicators are almost always incorporated as process indicators, rather than outcome measures. This review focuses on the quality indicators bowel preparation, cecal intubation rate, withdrawal time, adenoma detection rate, patient comfort, sedation and complication rate, and discusses the scientific evidence supporting them,as well as their potential shortcomings and issues that need to be addressed. For instance, there is still no clear and generally accepted definition of adequatebowel preparation, no robust scientific evidence is available supporting a cecal intubation rate ≥ 90% and the association between withdrawal time and occurrence of interval cancers has not been clarified. Adenoma detection rate is currently the only quality indicator that has been shown to be associated with interval colorectal cancer, but as an indicator it does not differentiate between subjects with one or more adenoma detected.

  6. Laparoscopic Splenectomy for Traumatic Splenic Injury after Screening Colonoscopy

    Directory of Open Access Journals (Sweden)

    Salim Abunnaja

    2012-09-01

    Full Text Available Colonoscopy is a widespread diagnostic and therapeutic procedure. The most common complications include bleeding and perforation. Splenic rupture following colonoscopy is rarely encountered and is most likely secondary to traction on the splenocolic ligament. Exploratory laparotomy and splenectomy is the most commonly employed therapeutic intervention for this injury reported in the literature. We present the case of a patient with this potentially fatal complication who was treated successfully at our institution. To our knowledge it is the first report in the literature of laparoscopic splenectomy as a successful minimally invasive treatment of splenic rupture following colonoscopy. The patient was a 62-year-old female who underwent screening colonoscopy with polypectomies at the cecum, descending colon and rectum. Immediately following the procedure she developed abdominal pain and had a syncopal episode. Clinical, laboratory and imaging findings were suggestive of hemoperitoneum and a ruptured spleen. A diagnostic laparoscopy was emergently performed and revealed a grade IV splenic laceration and hemoperitoneum. Laparoscopic splenectomy was completed safely and effectively. The patient’s postoperative recovery was uneventful. We conclude that splenic rupture after colonoscopy is a rare but dangerous complication. A high index of suspicion is required to recognize it early. Awareness of this potential complication can lead to optimal patient outcome. Laparoscopic splenectomy may be a feasible treatment option.

  7. Colorectal Cancer Surveillance after Index Colonoscopy: Guidance from the Canadian Association of Gastroenterology

    Directory of Open Access Journals (Sweden)

    Desmond Leddin

    2013-01-01

    Full Text Available BACKGROUND: Differences between American (United States [US] and European guidelines for colonoscopy surveillance may create confusion for the practicing clinician. Under- or overutilization of surveillance colonoscopy can impact patient care.

  8. Colonoscopia: morbidade negligenciada Colonoscopy: neglected morbidity

    Directory of Open Access Journals (Sweden)

    Fernanda Bellotti Formiga

    2009-09-01

    Full Text Available OBJETIVO: Avaliar fatores de risco que determinam morbidade ao exame de colonoscopia. MÉTODOS: No período de março a junho de 2009 foram analisados prospectivamente 170 pacientes submetidos a exame colonoscópico. Fatores de risco como idade, sexo, indicação, exame ambulatorial/internado, efeitos adversos e qualidade do preparo intestinal, procedimento endoscópico, diagnóstico e intercorrência peri-procedimento foram relacionados. RESULTADOS: A média de idade da amostra foi 60,16 ± 14,69 anos, com predominância do sexo feminino. A indicação mais prevalente do exame foi seguimento pós-operatório. Três exames foram inconclusivos por mau preparo. Do restante, 36,53% foram normais e a maioria dos alterados apresentou pólipos, adenomatosos predominantemente. Quanto as comorbidades, 48,82% dos pacientes possuíam alguma comorbidade, sendo Hipertensão Arterial Sistêmica a mais prevalente. Apenas 22,94% dos pacientes apresentaram algum efeito adverso ao preparo. O preparo foi limpo em 65,88% dos exames, mostrando significância quando comparado a morbidade. Outro fator de significância estatística foi a realização de procedimentos (44,7% dos exames, sendo a maioria polipectomias. A morbidade chegou a 16,47%, sendo a desidratação a mais prevalente. Não houve mortalidade. CONCLUSÃO: A qualidade do preparo intestinal e a realização de procedimento endoscópico são fatores diretamente relacionados a morbidade do exame de colonoscopia.OBJECTIVE: The objective of this study is to analyze risks factors of morbidity on colonoscopy. METHOD: From March to June of 2009, 170 patients were examined and analyzed prospectively. Risks factors as age, sex, indication of exam, ambulatory or hospital exam, adverse events and quality of intestinal preparation, endoscopic procedure, diagnoses and incident before, during or after procedure were analyzed. RESULTS: The average age was 60,16±14,69 years old, with majority of female. The prevalent

  9. Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels: Reliability of standard radiographs, CT scans, and 3D virtual reality images

    NARCIS (Netherlands)

    D.E. Meuffels (Duncan); J.W. Potters (Jan Willem); A.H.J. Koning (Anton); C.H. Brown Jr Jr. (Charles); J.A.N. Verhaar (Jan); M. Reijman (Max)

    2011-01-01

    textabstractBackground and purpose: Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans,

  10. Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels: Reliability of standard radiographs, CT scans, and 3D virtual reality images

    NARCIS (Netherlands)

    D.E. Meuffels (Duncan); J.W. Potters (Jan Willem); A.H.J. Koning (Anton); C.H. Brown Jr Jr. (Charles); J.A.N. Verhaar (Jan); M. Reijman (Max)

    2011-01-01

    textabstractBackground and purpose: Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, a

  11. Usefulness of CT angiography in diagnosing acute gastrointestinal bleeding:A meta-analysis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To analyze the accuracy of computed tomography (CT) angiography in the diagnosis of acute gastrointestinal (GI) bleeding. METHODS: The MEDLINE, EMBASE, Cancerlit, Cochrane Library database, Sciencedirect, Springerlink and Scopus, from January 1995 to December 2009, were searched for studies evaluating the accuracy of CT angiography in diagnosing acute GI bleeding. Studies were included if the ycompared CT angiography to a reference standard of upper GI endoscopy, colonoscopy, angiography or surgery in ...

  12. Automatic classification of images with appendiceal orifice in colonoscopy videos.

    Science.gov (United States)

    Cao, Yu; Liu, Danyu; Tavanapong, Wallapak; Wong, Johnny; Oh, JungHwan; de Groen, Piet C

    2006-01-01

    Colonoscopy is an endoscopic technique that allows a physician to inspect the inside of the human colon. In current practice, videos captured from colonoscopic procedures are not routinely stored for either manual or automated post-procedure analysis. In this paper, we introduce new algorithms for automated detection of the presence of the shape of the opening of the appendix in a colonoscopy video frame. The appearance of the appendix in colonoscopy videos indicates traversal of the colon, which is an important measurement for evaluating the quality of colonoscopic procedures. The proposed techniques are valuable for (1) establishment of an effective content-based retrieval system to facilitate endoscopic research and education; and (2) assessment and improvement of the procedural skills of endoscopists, both in training and practice.

  13. Procedural Skills Education – Colonoscopy as a Model

    Directory of Open Access Journals (Sweden)

    Maitreyi Raman

    2008-01-01

    Full Text Available Traditionally, surgical and procedural apprenticeship has been an assumed activity of students, without a formal educational context. With increasing barriers to patient and operating room access such as shorter work week hours for residents, and operating room and endoscopy time at a premium, alternate strategies to maximizing procedural skill development are being considered. Recently, the traditional surgical apprenticeship model has been challenged, with greater emphasis on the need for surgical and procedural skills training to be more transparent and for alternatives to patient-based training to be considered. Colonoscopy performance is a complex psychomotor skill requiring practioners to integrate multiple sensory inputs, and involves higher cortical centres for optimal performance. Colonoscopy skills involve mastery in the cognitive, technical and process domains. In the present review, we propose a model for teaching colonoscopy to the novice trainee based on educational theory.

  14. Syncope as the Presenting Feature of Splenic Rupture after Colonoscopy

    Directory of Open Access Journals (Sweden)

    Daniel Jamorabo

    2014-01-01

    Full Text Available Splenic rupture is a rare, catastrophic complication of colonoscopy and an exceptional cause of syncope. This injury is believed to be from direct trauma or tension on the splenocolic ligament with subsequent capsule avulsion or else from direct instrument-induced splenic injury. Diagnosis requires a high index of suspicion that may be absent because presentation can be subtle, nonspecific, and delayed anywhere from hours to days and therefore not easily attributed to a recent endoscopy. We describe a case of syncope as the initial manifestation of splenic rupture after colonoscopy. Our patient’s pain was delayed; his discomfort was mild and not localized to the left upper quadrant. Clinicians should consider syncope, lightheadedness, and drop in hemoglobin in absence of rectal bleeding following a colonoscopy as possible warning signs of imminent or emergent splenic injury.

  15. Assessment of colonoscopy by use of magnetic endoscopic imaging

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Preisler, Louise; Svendsen, Morten Bo Søndergaard;

    2015-01-01

    BACKGROUND: Yield and safety of colonoscopy are highly dependent on operator competence. Existing tools for assessing competence is time-consuming and based on direct observation, making them prone for bias. There is a need for an easily accessible, reliable, and valid measure of endoscopic...... performance. OBJECTIVE: The aim of this study was to develop and explore the validity of an automated, unbiased assessment tool. DESIGN: We tested 10 experienced endoscopists and 11 trainees in colonoscopy on a physical simulator (Kagaku Colonoscope Training Model). Participants were tested with an easy...... and a difficult case. SETTING: Center for Clinical Education, Capital Region of Denmark. MAIN OUTCOME MEASUREMENTS: By using magnetic endoscopic imaging, we developed a colonoscopy progression score (CoPS). A pass/fail score was established by using the contrast-group method. RESULTS: We found significant...

  16. Fospropofol disodium injection for the sedation of patients undergoing colonoscopy

    Directory of Open Access Journals (Sweden)

    Benjamin E Levitzky

    2008-09-01

    Full Text Available Benjamin E Levitzky1, John J Vargo21Department of Gastroenterology and Hepatology, 2Section of Therapeutic and Hepatobiliary Endoscopy, Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio, USAAbstract: Sedation plays a central role in making colonoscopy tolerable for patients and feasible for the endoscopist to perform. The array of agents used for endoscopic sedation continues to evolve. Fospropofol (FP, a prodrug of propofol with a slower pharmacokinetic profi le, is currently under evaluation for use during endoscopic procedures. Preliminary data suggests that FP dosed at 6.5 mg/kg is well tolerated by most patients with perineal paresthesias being the most commonly experienced adverse effect. This article will examine the current literature on the use of FP for the sedation of patients undergoing colonoscopy, highlighting the pharmacokinetics, pharmacodynamics, risks, and common adverse events associated with the novel sedative/hypnotic.Keywords: fospropofol, Aquavan, propofol, sedation, colonoscopy

  17. Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health '2-week-wait' initiative

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A.; Halligan, S. E-mail: s.halligan@ic.ac.uk; Saunders, B.P.; Morley, S.; Riesewyk, C.; Atkin, W.; Bartram, C.I

    2003-11-01

    AIM: Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario. MATERIALS AND METHODS: Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy. RESULTS: Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy. CONCLUSION: CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.

  18. Intravenous glucagon beneficial during colonoscopy in patient with IBS

    Directory of Open Access Journals (Sweden)

    Dharmesh H Kaswala

    2014-05-01

    Full Text Available Background and Aim: Irritable bowel syndrome (IBS is a functional bowel disorder characterized by abdominal pain or discomfort and altered bowel habits. Patients with IBS requiring colonoscopy take longer time to cecum with higher need for medications used for conscious sedation. Glucagon is routinely used during endoscopic procedures to reduce peristalsis that interfere with the procedure. However, randomized controlled data using glucagon during endoscopic procedures are lacking. We designed a prospective randomized placebo-controlled trial to study the effect of intravenous glucagon given during colonoscopy. Materials and Methods: We received approval from the FDA for this off-label use of glucagon during colonoscopy. This is a double-blind randomized placebo-controlled study. Patients were selected based on ROME III criteria for IBS; patients who met Rome III criteria and had an indication for colonoscopy for age-specific colon cancer screening or for work up of any alarm signs. We selected 34 patients meeting the Rome III for IBS and randomized into Group A and Group B. Both the performing endoscopist and patients were blinded. These patients in both groups initially received a standard dose of conscious sedation, up to 100 mcg of fentanyl and up to 5 mg of midazolam intravenously. In Group A, 17 patients, in addition to conscious sedation, received 1 ml saline as placebo. In Group B, 17 patients, in addition to conscious sedation, received 1 mg of intravenous glucagon. Parameters evaluated were as follows: 1 Total time required for colonoscopy 2 Completion of colonoscopy as documented by cecal intubation or visualization of appendicular orifice 3 Level of comfort in patient concerned to post- procedure spasmodic pain, which was based on Wong-Baker FACES pain rating scale and 4 Calculate the amount of sedation required in both groups of patients and also at what extent glucagon helped to decrease the requirement of sedatives. Data was

  19. A Case of Taenia asiatica Infection Diagnosed by Colonoscopy

    Science.gov (United States)

    Kim, Heung Up; Chung, Young-Bae

    2017-01-01

    A case of Taenia asiatica infection detected by small bowel series and colonoscopy is described. The patient was a 42-year-old Korean man accompanied by discharge of movable proglottids via anus. He used to eat raw pig liver but seldom ate beef. Small bowel series radiologic examinations showed flat tape-like filling defects on the ileum. By colonoscopy, a moving flat tapeworm was observed from the terminal ileum to the ascending colon. The tapeworm was identified as T. asiatica by mitochondrial DNA sequencing. The patient was prescribed with a single oral dose (16 mg/kg) of praziquantel. PMID:28285508

  20. Fospropofol disodium injection for the sedation of patients undergoing colonoscopy.

    Science.gov (United States)

    Levitzky, Benjamin E; Vargo, John J

    2008-08-01

    Sedation plays a central role in making colonoscopy tolerable for patients and feasible for the endoscopist to perform. The array of agents used for endoscopic sedation continues to evolve. Fospropofol (FP), a prodrug of propofol with a slower pharmacokinetic profile, is currently under evaluation for use during endoscopic procedures. Preliminary data suggests that FP dosed at 6.5 mg/kg is well tolerated by most patients with perineal paresthesias being the most commonly experienced adverse effect. This article will examine the current literature on the use of FP for the sedation of patients undergoing colonoscopy, highlighting the pharmacokinetics, pharmacodynamics, risks, and common adverse events associated with the novel sedative/hypnotic.

  1. CT Virtual Bronchoscopy: Imaging Method and Clinical Application%螺旋CT仿真支气管内窥镜成像方法及其临床应用

    Institute of Scientific and Technical Information of China (English)

    熊明辉; 张挽时; 王东; 宋云龙; 鲁晓燕; 时惠平

    2001-01-01

    Purpose: To evaluate imaging methods and clinical application of CT virtual bronchoscopy (VB). Meterials and Methods: Fifty-tvo cases were performed by using spiral CT (Hispeed Advantage CT/i), the data were transferred to computer workstation (Advantage Windows 3.1). The CTVB images were generated from using Navigator Smooth soft-ware and compared with fiberoptic bronchoscopy. 4 cases of them were correlated with pathologic samples. Results: CTVB could reveal 100% segmental bronchi and more than 80% subsegmental bronchi mimicking fiberoptic bron- choscopy. Arnong the 27 patients with lung cancer of center type, bronchial stenosis (n= 23) and occlusions (n= 4) were due to masses. Post-oper- ated residual bronchial sstumps (n=4) sbowed sooth blinds. One case exhibited the bronchial diverticulum in the right bronchus. Conclusions: CTVB provided a noninvasive fiberoptic bronchoscopelike image, but it can not replace fiberoptic endoscopy for demonstrating mucosal abnormalities and for obtaining histologic samples.%评价螺旋CT仿真支气管内窥镜(CTVB)临床应用价值。材料和方法:对52例气管、支气管行螺旋CT(GE HiSoeedAdvantageCT/i)扫描,将其数据传至AdvantageWindows 3.1版本工作站,用NavigatorSmooth软件建成酷似纤维支 气管镜所见的CTVB图像,并与纤维支气管镜对照。其中4例与病理标本对照。结果:CTVB能100%地观察到段以上支 气管和80%以上亚段支气管。27例中心型肺癌发现支气管狭窄23例,闭塞4例,肺癌术后支气管残端4例,气管狭窄2 例,右中间段支气管憩室1例。结论:CTVB是一种新的无创性观察气管、支气管腔的方法,酷似纤维支气管镜所见,但在 观察支气管粘膜的表浅病变和获取组织学标本方面不能取代纤维支气管镜。

  2. Organizaciones Virtuales Organizaciones Virtuales

    Directory of Open Access Journals (Sweden)

    Gladis Cecilia Villegas Arias

    2003-06-01

    Full Text Available Virtual Organizations are new organizational forms originated from both the replacementof face to face communications by remote communications supported by electronic means,and from the accesibility of real time information about the operation of the company, forall employees.This article pursues the following goals: 1 To define virtual organization, review its sociotechnical antecedents and propose a preliminary classification into inter-organizationaland intra-organizational forms.  2 To discuss the characteristics of virtual organizationsand their impact on organizational design, and 3 To compare virtual organizations toother organizational forms.Las organizaciones virtuales son formas organizativas nuevas, que resultan de: primero, reemplazar las interacciones cara a cara con interacciones remotas, soportadas por comunicaciones electrónicas y segundo,  proveer acceso en tiempo real a toda la información de la empresa para todos los trabajadores.En este artículo se busca: 1 Definir organización virtual, revisar sus antecedentes y proponeruna clasificación básica preliminar de las mismas  2 Discutir las características de las organizaciones virtuales y sus implicaciones para el diseño organizativo 3 Comparar estaforma organizativa a las formas organizativas no virtuales.

  3. Virtually teaching virtual leadership

    DEFF Research Database (Denmark)

    Henriksen, Thomas Duus; Nielsen, Rikke Kristine; Børgesen, Kenneth

    2017-01-01

    This paper seeks to investigate the challenges to virtual collaboration and leadership on basis of findings from a virtual course on collaboration and leadership. The course used for this experiment was designed as a practical approach, which allowed participants to experience curriculum phenomen...

  4. Virtual operation planning in orthopedic surgery for acetabular fractures based on real CT data%基于真实CT数据骨科虚拟手术计划在髋臼骨折手术中的运用

    Institute of Scientific and Technical Information of China (English)

    汪光晔; 张春才; 许硕贵; 薜双桃; 林清高

    2011-01-01

    BACKGROUND: Virtual operation planning can help surgeons to improve the accuracy of orthopedic operations. OBJECTIVE:To test the feasibility and clinical value of preoperative virtual surgical planning in pelvis and acetabular fractures using Mimics software based on an interactive virtual reality-style environment.METHODS: Thirteen patients with pelvis and acetabular fractures were scanned with spiral CT preoperatively. The real data from CT in DICOM format were transformed into Mimics software. With segmentation process, each fracture segment became a separate object. Bone fragments could be moved and rotated in all three planes and reduction was performed Then we performed all the steps of the surgical procedure.RESULTS AND CONCLUSION: The median time needed to segment the osseous parts of an entire pelvis and to extract a surface model was 45 minutes (ranging 30 to 70 minutes), and the median time for fracture reduction was 28 minutes (ranging 16 to 45 minutes). The planned approach was followed in 12 of the 13 cases, the planned fixation was followed completely in 12 cases and partially in 1 cases. The screw count was identical to the planned operation in 10 cases, the screw length was Identical in 8 cases, and fixation plate count was Identical in 11 cases. Postoperative congruence of the acetabular joint surface as determined according to Matta in the follow-up CT was anatomic in 6 cases (46%) and satisfactory In 7 cases (54%). There was no case with inadvertent penetration of the hip joint Virtual operation planning in orthopedic surgery is helpful for enacting accurate operation program and providing data reference for actual operation, which brings significant value and new opportunities in clinical practice.%背景:骨科虚拟手术计划有助于提高外科医生的手术精确性.目的:探索计算机术前模拟手术技术在骨盆、髋臼骨折的治疗中的应用方法及临床价值.方法:对13例骨盆及髋臼骨折患者进行螺旋CT影

  5. Technical interventions to increase adenoma detection rate in colonoscopy.

    Science.gov (United States)

    Rondonotti, Emanuele; Andrealli, Alida; Amato, Arnaldo; Paggi, Silvia; Conti, Clara Benedetta; Spinzi, Giancarlo; Radaelli, Franco

    2016-12-01

    Adenoma detection rate (ADR) is the most robust colonoscopy quality metric and clinical studies have adopted it as the ideal method to assess the impact of technical interventions. Areas covered: We reviewed papers focusing on the impact of colonoscopy technical issues on ADR, including withdrawal time and technique, second evaluation of the right colon, patient positional changes, gastrointestinal assistant participation during colonoscopy, water-aided technique, optimization of bowel preparation and antispasmodic administration. Expert commentary: Overall, technical interventions are inexpensive, available worldwide and easy to implement. Some of them, such as the adoption of split dose regimen and slow scope withdrawal to allow a careful inspection, have been demonstrated to significantly improve ADR. Emerging data support the use of water-exchange colonoscopy. According to published studies, other technical interventions seem to provide only marginal benefit to ADR. Unfortunately, the available evidence has methodological limitations, such as small sample sizes, the inclusion of expert endoscopists only and the evaluation of single technical interventions. Additionally, larger studies are needed to clarify whether these interventions might have a higher benefit on low adenoma detectors and whether the implementation of a bundle of them, instead of a single technical maneuver, might have a greater impact on ADR.

  6. Enteroscope without overtube for cecal intubation after an incomplete colonoscopy.

    Science.gov (United States)

    Coppola, Franco; Gaia, Silvia; Cosimato, Maurizio; Recchia, Serafino

    2011-06-01

    Cecal intubation is one of the targets of colon endoscopic evaluation, however even under experienced hands 5-10% of colonoscopies are incomplete. The aim of the study is to evaluate the usefulness of single balloon enteroscope (SBE) without employing overtube-balloon equipment in patients with incomplete colonoscopy. Between January 2009 and July 2010, patients with an incomplete standard colonscopy were prospectively enrolled to perform a colonoscopy with a single balloon enteroscope. Examinations were performed by the same expert operator during the same session. Enteroscopy was performed on 79 patients, cecal intubation were obtained in 93.6% of the cases (74/79). It provided a new diagnosis in 43% of cases (34/79). Procedure was safe and well tolerated. Overall the additional use of single balloon enteroscope allowed to obtain the cecal intubation in up to 99.2% cases (898/905). The use of the enteroscope without overtube-balloon equipment may be an effective method to increase the cecal intubation rate after failure of a standard colonoscopy. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  7. Polyp detection at colonoscopy: Endoscopist and technical factors.

    Science.gov (United States)

    Rex, Douglas K

    2017-08-01

    The adenoma detection rate (ADR) has emerged as the most important quality measure in colonoscopy, as it predicts the risk of interval cancer after colonoscopy. Measuring and improving ADR is the central focus of the current quality movement in colonoscopy. High ADRs can be achieved by a colonoscopist with a thorough understanding of the wide range of endoscopic appearances of precancerous lesions in the colorectum, effective bowel preparation, and meticulous technique using high definition colonoscopes. The knowledgeable and effective examiner needs no adjunctive devices or techniques to achieve master level ADRs. However, measurement reveals that many colonoscopists have ADRs that are below recommended minimum thresholds or below master levels. These colonoscopists, and even master level performers, can choose from a variety of adjunctive tools to improve ADR. This review describes these tools according to whether they are non-device methods (e.g. double right colon examination, patient position change, water exchange), mucosal exposure devices (wide angle colonoscopy, fold flattening devices), and lesion highlighting techniques (e.g. chromoendoscopy, electronic chromoendoscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Management of anticoagulants and antiplatelet agents during colonoscopy.

    Science.gov (United States)

    Feagins, Linda Anne

    2017-03-23

    Colonoscopy frequently is performed for patients who are taking aspirin, NSAIDs, antiplatelet agents and other anticoagulants. These colonoscopies often involve polypectomy, which can be complicated by bleeding. The risks of precipitating thromboembolic complications if anticoagulants are stopped must be weighed against the risk of postpolypectomy bleeding if these agents are continued. This article systematically reviews the management of anticoagulation during elective and emergency colonoscopy. For patients undergoing colonoscopic polypectomy, the overall of risk of postpolypectomy bleeding is less than 0.5%. Risk factors for postpolypectomy bleeding include large polyp size and anticoagulant use, especially warfarin and thienopyridines. For patients who do not stop aspirin or other NSAIDs prior to colonoscopy, the rate of postpolypectomy bleeding is not significantly different than that for patients who do not take those medications. For patients who continue thienopyridines and undergo polypectomy, the risk of delayed postpolypectomy bleeding is approximately 2.4%. Even for patients who interrupt warfarin, the risk of postpolypectomy bleeding is increased. The direct oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) have a rapid onset and offset of action, and periprocedural bridging generally is not necessary. For the thienopyridines, warfarin and the direct oral anticoagulants, the decision to interrupt or continue these agents for endoscopy will involve considerable exercise of clinical judgment.

  9. Towards clinically translatable NIR fluorescence molecular guidance for colonoscopy

    NARCIS (Netherlands)

    Garcia-Allende, P. Beatriz; Glatz, Juergen; Koch, Maximilian; Tjalma, Jolien J.; Hartmans, Elmire; Terwisscha Van Scheltinga, Anton G. T.; Symvoulidis, Panagiotis; van Dam, Gooitzen M.; Nagengast, Wouter B.; Ntziachristos, Vasilis

    2014-01-01

    White-light surveillance colonoscopy is the standard of care for the detection and removal of premalignant lesions to prevent colorectal cancer, and the main screening recommendation following treatment for recurrence detection. However, it lacks sufficient diagnostic yield, exhibits unacceptable ad

  10. [Colonoscopy quality control as a requirement of colorectal cancer screening].

    Science.gov (United States)

    Quintero, Enrique; Alarcón-Fernández, Onofre; Jover, Rodrigo

    2013-11-01

    The strategies used in population-based colorectal screening strategies culminate in colonoscopy and consequently the success of these programs largely depends on the quality of this diagnostic test. The main factors to consider when evaluating quality are scientific-technical quality, safety, patient satisfaction, and accessibility. Quality indicators allow variability among hospitals, endoscopy units and endoscopists to be determined and can identify those not achieving recommended standards. In Spain, the working group for colonoscopy quality of the Spanish Society of Gastroenterology and the Spanish Society of Gastrointestinal Endoscopy have recently drawn up a Clinical Practice Guideline that contains the available evidence on the quality of screening colonoscopy, as well as the basic requirements that must be met by endoscopy units and endoscopists carrying out this procedure. The implementation of training programs and screening colonoscopy quality controls are strongly recommended to guarantee the success of population-based colorectal cancer screening. Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.

  11. Does type of instrument influence colonoscopy performance and sedation practice?

    Institute of Scientific and Technical Information of China (English)

    Ramesh P Arasaradnam; Paul D Hurlstone

    2007-01-01

    @@ TO THE EDITOR In the UK, clear guidelines exist as to the expected levelof competence an individual endoscopist should achieve.This is of utmost importance given the variance inpractice among endoscopic departments as highlightedby the National Colonoscopy audit in 2002[1]. The auditedvariables included sedation practice, caecal completion andcomtlication rates, but not the Wpe of instrument used.

  12. Assessment of quality in screening colonoscopy for colorectal cancer

    Directory of Open Access Journals (Sweden)

    Gonçalves AR

    2011-12-01

    Full Text Available Ana Rita Gonçalves, Carlos Ferreira, António Marques, Luís Carrilho Ribeiro, José VelosaDepartment of Gastroenterology and Hepatology, Hospital Santa Maria-CHLN, Lisboa 1068, PortugalIntroduction: The effectiveness of screening colonoscopy in decreasing the incidence of colorectal cancer (CRC is largely dependent on the detection of polyps and the quality of the procedure. Several key quality measures have been proposed to improve the effectiveness of screening colonoscopies.Aim: To evaluate quality indicators of screening colonoscopy in a tertiary hospital.Methods: All CRC screening colonoscopies performed between 2005 and 2009 in a single tertiary center were reviewed for internationally accepted quality measures.Results: Of the 1545 individuals who underwent first-time screening colonoscopy 38% were male and 62% were female. The mean age of the patients was 60.4 years and the mean difference in ages was ± 10.3 years. Cecal intubation rate was 91% (1336, however ileocecal valve photo documentation was performed in only 81% (1248 colonoscopies. The quality of bowel preparation was classified as: good 76% (1171, reasonable 11% (174, and poor 13% (200. Polyp detection rate (PDR was 33% (503. The prevalence of polyps ≥1 cm in size was 5% (82. PDR was significantly higher in men than in women (44% [260] vs 25% [243], P = 0.0001. Other factors significantly influencing PDR were quality of bowel preparation (odds ratio [OR]: 1.28, 95% confidence interval [CI]: 0.9–1.6 and age over 50 (OR: 1.9, 95% CI: 1.3–2.9. Left colonic polyps were associated with a risk ratio of 2.3 (95% CI: 1.8–2.9 of lesions in the other colonic segments compared to no polyps in the left colon. None of the colonoscopists reported withdrawal time.Conclusion: Cecal intubation rate and quality of bowel preparation were suboptimal. The polyp detection rate compares favorably to accepted standards and its main determinants are male sex, age >50 years, quality of bowel

  13. A noise-optimized virtual monochromatic reconstruction algorithm improves stent visualization and diagnostic accuracy for detection of in-stent re-stenosis in lower extremity run-off CT angiography.

    Science.gov (United States)

    Mangold, Stefanie; De Cecco, Carlo N; Schoepf, U Joseph; Yamada, Ricardo T; Varga-Szemes, Akos; Stubenrauch, Andrew C; Caruso, Damiano; Fuller, Stephen R; Vogl, Thomas J; Nikolaou, Konstantin; Todoran, Thomas M; Wichmann, Julian L

    2016-12-01

    To evaluate the impact of noise-optimized virtual monochromatic imaging (VMI+) on stent visualization and accuracy for in-stent re-stenosis at lower extremity dual-energy CT angiography (DE-CTA). We evaluated third-generation dual-source DE-CTA studies in 31 patients with prior stent placement. Images were reconstructed with linear blending (F_0.5) and VMI+ at 40-150 keV. In-stent luminal diameter was measured and contrast-to-noise ratio (CNR) calculated. Diagnostic confidence was determined using a five-point scale. In 21 patients with invasive catheter angiography, accuracy for significant re-stenosis (≥50 %) was assessed at F_0.5 and 80 keV-VMI+ chosen as the optimal energy level based on image-quality analysis. At CTA, 45 stents were present. DSA was available for 28 stents whereas 12 stents showed significant re-stenosis. CNR was significantly higher with ≤80 keV-VMI+ (17.9 ± 6.4-33.7 ± 12.3) compared to F_0.5 (16.9 ± 4.8; all p VMI+ (4.90 ± 0.48-4.88 ± 0.63 vs. 4.60 ± 0.66, p = 0.001, 0.0042). Sensitivity, negative predictive value and accuracy for re-stenosis were higher with 80 keV-VMI+ (100, 100, 96.4 %) than F_0.5 (90.9, 94.1, 89.3 %). 80 keV-VMI+ improves image quality, diagnostic confidence and accuracy for stent evaluation at lower extremity DE-CTA. • The impact of noise-optimized virtual monochromatic imaging on stent visualization was assessed. • Virtual monochromatic imaging significantly improves stent lumen visualization and diagnostic confidence. • At 80 keV diagnostic performance for detection of in-stent restenosis was increased. • 80 keV virtual monochromatic images are recommended for stent evaluation of lower extremity vasculature.

  14. Thoracic CT

    Science.gov (United States)

    ... lungs; CT scan - chest Images CT scan Thyroid cancer - CT scan Pulmonary nodule, solitary - CT scan Lung mass, right upper ... Chest Injuries and Disorders CT Scans Emphysema Lung Cancer Lung Diseases Pleural Disorders Pneumonia Pulmonary Embolism Tuberculosis Browse the Encyclopedia A.D.A. ...

  15. Virtual computed tomography cystoscopy in bladder pathologies

    Directory of Open Access Journals (Sweden)

    Halil Arslan

    2006-04-01

    Full Text Available OBJECTIVE: Assessed the usefulness of virtual cystoscopy performed with multidetector computed tomography (CT in patients with different urinary bladder pathologies compared to the conventional cystoscopy. MATERIALS AND METHODS: Eighteen patients with different bladder pathologies, which consisted of 11 tumors, 3 diverticula, 2 trabecular changes and 2 stones, were assessed with conventional cystoscopy and virtual CT cystoscopy. The results of virtual CT cystoscopy were compared with the findings of conventional cystoscopy. We determined the detection rate and positive predictive value of CT imaging based virtual cystoscopy in the diagnosis of urinary bladder lesions. RESULTS: CT scanning was well tolerated by all patients, and no complications occurred. Images in 16 (88% of the 18 virtual cystoscopic examinations were either of excellent or good quality. All tumors except one, 2 trabecular changes and 2 stones were characterized with similar findings in the both of methods. The masses ranged from 0.4 to 7.0 cm in diameter. While conventional cystoscopy could not evaluate interior part of the diverticulum, virtual CT cystoscopy could demonstrate clearly within it. There were no false-positive findings in our series. CONCLUSION: Virtual CT cystoscopy is a promising technique to be used in the detection of bladder lesions. It should be considered especially at the evaluation of bladder diverticula. In the future, it may be possible or even advantageous to incorporate into the imaging algorithm for evaluation of bladder lesion.

  16. Virtual computed tomography cystoscopy in bladder pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Halil; Ceylan, Kadir; Harman, Mustafa; Yilmaz, Yuksel; Temizoz, Osman; Can, Saban [Yuzuncu Yil University School of Medicine, Van (Turkey). Dept. of Radiology and Urology]. E-mail: drhalilarslan@hotmail.com

    2006-03-15

    Objective: assessed the usefulness of virtual cystoscopy performed with multidetector computed tomography (CT) in patients with different urinary bladder pathologies compared to the conventional cystoscopy.Materials and methods: eighteen patients with different bladder pathologies, which consisted of 11 tumors, 3 diverticula, 2 trabecular changes and 2 stones, were assessed with conventional cystoscopy and virtual CT cystoscopy. The results of virtual CT cystoscopy were compared with the findings of conventional cystoscopy. We determined the detection rate and positive predictive value of CT imaging based virtual cystoscopy in the diagnosis of urinary bladder lesions. Results: CT scanning was well tolerated by all patients, and no complications occurred. Images in 16 (88%) of the 18 virtual cystoscopic examinations were either of excellent or good quality. All tumors except one, 2 trabecular changes and 2 stones were characterized with similar findings in the both of methods. The masses ranged from 0.4 to 7.0 cm in diameter. While conventional cystoscopy could not evaluate interior part of the diverticulum, virtual CT cystoscopy could demonstrate clearly within it. There were no false-positive findings in our series. Conclusion: virtual CT cystoscopy is a promising technique to be used in the detection of bladder lesions. It should be considered especially at the evaluation of bladder diverticula. In the future, it may be possible or even advantageous to incorporate into the imaging algorithm for evaluation of bladder lesion. (author)

  17. Indications and findings at colonoscopy in Ilorin, Nigeria

    Directory of Open Access Journals (Sweden)

    Abdulfatai Bamidele Olokoba

    2013-01-01

    Full Text Available Background: Colonoscopy is a safe and effective means of visual inspection of the large bowel from the distal rectum to the caecum. It may be carried out for diagnostic and or therapeutic reasons. There is a paucity of data on this procedure in Nigeria. We, therefore, determined the indications, findings, and diagnostic yield in Nigerians at colonoscopy. Materials and Methods: This was a hospital-based cross-sectional study carried out at the Endoscopy unit of Crescent hospital, Ilorin from January 2010 to May, 2012. The endoscopy register was reviewed, and the biodata, indications and colonoscopic findings were recorded on a pro forma. Results: A total of 103 patients had colonoscopy. Seventy (68.0% were males while 33 (32.0% were females. The indications for colonoscopy were rectal bleeding 41 (39.8%, suspected colon cancer 32 (31.1%, chronic constipation and chronic diarrhoea nine each (8.7%, abdominal/anal pain five (4.9%, suspected anorectal cancer and enterocutaneous fistula two each (1.9%, faecal incontinence, occult gastrointestinal bleeding, post-colostomy for Hirschsprung disease one each (1.0%. Endoscopic findings were normal findings 21 (20.4%, diverticulosis 17 (16.5%, polyps 16 (15.5%, haemorrhoids 16 (15.5%, anorectal cancer 13 (12.6%, angiodysplasia 12 (11.7%, colon cancer eight (7.8%, colitis 7 (6.8%, anorectal ulcer 4 (3.9%, anal warts two (1.9%, anal fissure, caecal tumour, faecal impaction and proctitis one each (1.0%. The diagnostic yield was 79.6%. Conclusions: The commonest indication for colonoscopy was rectal bleeding, while the most frequent pathology was diverticulosis. The diagnostic yield was high.

  18. Evaluation on the virtual CT endotoscope for the diagnosis of ossicular chain lesions accompanied with congenital aural deformity%虚拟CT耳镜对先天性耳畸形听骨链病变的诊断价值

    Institute of Scientific and Technical Information of China (English)

    蒋立新; 涂博; 罗冬

    2011-01-01

    目的 通过虚拟CT耳镜观察,探讨其对先天性耳畸形听骨链病变的诊断价值.方法 对30例(43耳)先天性耳畸形患者,高分辨率CT扫描获取病变部位的原始图像数据,经三维重建后,以虚拟CT耳镜方式观察听骨链病变情况,然后与手术探查结果对比分析.结果 虚拟CT耳镜清楚显示发育不全的听小骨及畸形听骨链状态,其中外耳道闭锁21例(30耳),包括锤骨发育不全18耳,砧骨发育不全13耳,锤砧骨缺如3耳,镫骨畸形13耳,镫骨缺如4耳,锤砧关节畸形融合20耳,砧镫关节畸形融合7耳,砧镫关节软组织连接2耳;9例(13耳)单纯性中耳畸形,其中锤骨头与砧骨体包埋在上鼓室内上壁2耳,锤骨头与上鼓室壁骨性连接3耳,锤骨柄远端与鼓环骨性连接1耳,砧骨长脚发育不全4耳,镫骨异位1耳,镫上结构缺如3耳,其中前庭窗闭锁1耳,镫上结构畸形2耳.31耳行手术治疗,术前虚拟CT耳镜观察与术中探查听骨链异常基本符合.结论 虚拟CT耳镜清楚显示先天性耳畸形听骨链异常结构,为术前明确诊断和确立手术方式提供可靠的影像学依据.%Objective To investigate the value of virtual CT endotoscope for the diagnosis of ossicular chain lesions accompanied with congenital aural deformity. Methods Thirty cases (43 ears) with congenital aural deformity were undergone high resolution CT scanning to collect the original image data from the focus in middle ear, followed by 3-dimensional reconstruction to process these images for evaluating the possibly presented lesions with the ossicular chain. Then, a comparative analysis was made on the virtual CT endotoscopic findings in a correlative consideration with that actually found during the operation on the ossicular chain lesions. Results 30 ears were aural atresia which contained malleus hypoplasia in 18 ears, incus hypoplasia in 13 ears, malleus and incus absence in 3 ears, stapes abnormity in 13 ears, stapes absence in

  19. Cost Effectiveness of Screening Colonoscopy Depends on Adequate Bowel Preparation Rates – A Modeling Study

    Science.gov (United States)

    Kingsley, James; Karanth, Siddharth; Revere, Frances Lee

    2016-01-01

    Background Inadequate bowel preparation during screening colonoscopy necessitates repeating colonoscopy. Studies suggest inadequate bowel preparation rates of 20–60%. This increases the cost of colonoscopy for our society. Aim The aim of this study is to determine the impact of inadequate bowel preparation rate on the cost effectiveness of colonoscopy compared to other screening strategies for colorectal cancer (CRC). Methods A microsimulation model of CRC screening strategies for the general population at average risk for CRC. The strategies include fecal immunochemistry test (FIT) every year, colonoscopy every ten years, sigmoidoscopy every five years, or stool DNA test every 3 years. The screening could be performed at private practice offices, outpatient hospitals, and ambulatory surgical centers. Results At the current assumed inadequate bowel preparation rate of 25%, the cost of colonoscopy as a screening strategy is above society’s willingness to pay (<$50,000/QALY). Threshold analysis demonstrated that an inadequate bowel preparation rate of 13% or less is necessary before colonoscopy is considered more cost effective than FIT. At inadequate bowel preparation rates of 25%, colonoscopy is still more cost effective compared to sigmoidoscopy and stool DNA test. Sensitivity analysis of all inputs adjusted by ±10% showed incremental cost effectiveness ratio values were influenced most by the specificity, adherence, and sensitivity of FIT and colonoscopy. Conclusions Screening colonoscopy is not a cost effective strategy when compared with fecal immunochemical test, as long as the inadequate bowel preparation rate is greater than 13%. PMID:27936028

  20. The virtual knife

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann

    and order books. The Danish Meat Research Institute (DMRI) is currently constructing a representative database of virtual representations of pigs using X-ray Computed Tomography (CT). The database will serve as the foundation for the diversity modeling of pigs and for extracting predictors of quality...... and optimal use. This thesis integrates well-known techniques from the medical image analysis into the development of tools for automated analysis of the morphology of pigs. E.g. elastic image matching has been applied to establish spatial correspondence between the virtual representations of pigs...

  1. Limited-preparation CT colonography in frail elderly patients: a feasibility study.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2010-05-01

    Full colonic preparation can be onerous and may be poorly tolerated in frail elderly patients. The purpose of this study was to prospectively assess the image quality and diagnostic yield of limited-preparation CT colonography (CTC) in elderly patients with suspected colorectal cancer who were deemed medically unfit or unsuitable for colonoscopy.

  2. Performance of CT Colonography for Detecting Small Diminutive and Flat Polyps

    Science.gov (United States)

    2010-04-01

    CT colonography with pig colonic specimens. Radiology 2007;244(1):157–64. 47. Pickhardt PJ, Kim DH, Cash BD, et al. The natural history of small...determined by back-to-back colonoscopies. Gastroenterology 1997;112(1):24–8. 61. Lefere PA, Gryspeerdt SS, Dewyspelaere J, et al. Dietary fecal tagging as a

  3. Fecal microbiota transplantation via colonoscopy for recurrent C. difficile Infection.

    Science.gov (United States)

    Allegretti, Jessica R; Korzenik, Joshua R; Hamilton, Matthew J

    2014-12-08

    Fecal Microbiota Transplantation (FMT) is a safe and highly effective treatment for recurrent and refractory C. difficile infection (CDI). Various methods of FMT administration have been reported in the literature including nasogastric tube, upper endoscopy, enema and colonoscopy. FMT via colonoscopy yields excellent cure rates and is also well tolerated. We have found that patients find this an acceptable and tolerable mode of delivery. At our Center, we have initiated a fecal transplant program for patients with recurrent or refractory CDI. We have developed a protocol using an iterative process of revision and have performed 24 fecal transplants on 22 patients with success rates comparable to the current published literature. A systematic approach to patient and donor screening, preparation of stool, and delivery of the stool maximizes therapeutic success. Here we detail each step of the FMT protocol that can be carried out at any endoscopy center with a high degree of safety and success.

  4. Diverticular disease in CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, P.; Gryspeerdt, S.; Baekelandt, M.; Holsbeeck, B. van [Dept. of Radiology, Roeselare (Belgium); Dewyspelaere, J. [Dept. of Gastroenterology, Roeselare (Belgium)

    2003-12-01

    The aim of this study was to evaluate findings on CT colonography (CTC) in patients with diverticular disease. In a retrospective analysis of 160 consecutive patients, who underwent CTC and conventional colonoscopy (CC), patients with diverticular disease were retrieved. The CTC images were compared with CC and, if possible, with pathology. Findings on both 2D and 3D images are illustrated with emphasis on diagnostic problems and the possible solutions to overcome these problems. Several aspects of diverticulosis were detected: prediverticulosis (3%); global (55.6%); and focal wall thickening (4%) caused by thickened haustral folds, fibrosis, inflammation and adenocarcinoma; diverticula (52%); pseudopolypoid lesions caused by diverticular fecaliths (39%); inverted diverticula (1.2%); and mucosal prolapse (0.6%). Solutions to overcome pitfalls are described as abdominal windowing, content of the pseudopolypoid lesion, comparison of 2D and 3D images, prone-supine imaging and the aspect of the pericolic fat. In this series there were equivocal findings in case of mucosal prolapse (0.6%) and focal wall thickening (4%). Diverticulosis is a challenge for CTC to avoid false-positive diagnosis of polypoid and tumoral disease. Knowledge of possible false causes of polypoid disease and comparison of 2D and 3D images are necessary to avoid false-positive diagnosis. In case of equivocal findings additional conventional colonoscopy should be advised whenever a clinically significant lesion ({>=}1 cm) is suspected. (orig.)

  5. Virtual positron emission tomography/computed tomography-bronchoscopy: possibilities, advantages and limitations of clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Seemann, Marcus D. [University of Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Schaefer, Juergen F. [Eberhard-Karls University, Department of Diagnostic Radiology, Tuebingen (Germany); Englmeier, Karl-Hans [Institute of Medical Informatics, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

    2007-03-15

    The aim of this study was to demonstrate the possibilities, advantages and limitations of virtual bronchoscopy using data sets from positron emission tomography (PET) and computed tomography (CT). Twelve consecutive patients with lung cancer underwent PET/CT. PET was performed with F-18-labelled 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG). The tracheobronchial system was segmented with a volume-growing algorithm, using the CT data sets, and visualized with a shaded-surface rendering method. The primary tumours and the lymph node metastases were segmented for virtual CT-bronchoscopy using the CT data set and for virtual PET/CT-bronchoscopy using the PET/CT data set. Virtual CT-bronchoscopy using the low-dose or diagnostic CT facilitates the detection of anatomical/morphological structure changes of the tracheobronchial system. Virtual PET/CT-bronchoscopy was superior to virtual CT-bronchoscopy in the detection of lymph node metastases (P=0.001), because it uses the CT information and the molecular/metabolic information from PET. Virtual PET/CT-bronchoscopy with a transparent colour-coded shaded-surface rendering model is expected to improve the diagnostic accuracy of identification and characterization of malignancies, assessment of tumour staging, differentiation of viable tumour tissue from atelectases and scars, verification of infections, evaluation of therapeutic response and detection of an early stage of recurrence that is not detectable or is misjudged in comparison with virtual CT-bronchoscopy. (orig.)

  6. Fospropofol disodium injection for the sedation of patients undergoing colonoscopy

    OpenAIRE

    Levitzky, Benjamin E; Vargo, John J.

    2008-01-01

    Benjamin E Levitzky1, John J Vargo21Department of Gastroenterology and Hepatology, 2Section of Therapeutic and Hepatobiliary Endoscopy, Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio, USAAbstract: Sedation plays a central role in making colonoscopy tolerable for patients and feasible for the endoscopist to perform. The array of agents used for endoscopic sedation continues to evolve. Fospropofol (FP), a prodrug of propofol with a slower pharmacokin...

  7. Visuo-spatial ability in colonoscopy simulator training

    OpenAIRE

    Luursema, J.-M.; Buzink, S.N.; Verwey, W.B.; Jakimowicz, J.J.

    2010-01-01

    Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To remedy this situation, the current study investigated the role of a broad range of visuo-spatial factors in colonoscopy simulator training. Fifteen medical trainees (no clinical experience in colo...

  8. Accidental IV administration of epinephrine instead of midazolam at colonoscopy

    Directory of Open Access Journals (Sweden)

    Ahmed Gado

    2016-03-01

    Full Text Available Drug administration errors appear to be a major source of iatrogenic harm to hospitalized patients. They often, particularly in the case of epinephrine, have catastrophic consequences both for the patient and the well-meaning provider. The following incident is a medication error case report which illustrates one way that incorrect medication may be administered. IV epinephrine was accidentally administered instead of midazolam at colonoscopy.

  9. Effective colonoscopy training techniques: strategies to improve patient outcomes

    OpenAIRE

    Papanikolaou IS; Karatzas PS; Varytimiadis LT; Tsigaridas A; Galanopoulos M; Viazis N; Karamanolis DG

    2016-01-01

    Ioannis S Papanikolaou,1 Pantelis S Karatzas,2 Lazaros T Varytimiadis,2 Athanasios Tsigaridas,2 Michail Galanopoulos,2 Nikos Viazis,2 Dimitrios G Karamanolis21Hepato-gastroenterology Unit, 2nd Department of Internal Medicine, Attikon University General Hospital, University of Athens, 2Gastroenterology Department, Evangelismos Hospital, Athens, GreeceAbstract: Colonoscopy has substantially evolved during the last 20 years and many different training techniques have been developed in order to i...

  10. Reiki as a pain management adjunct in screening colonoscopy.

    Science.gov (United States)

    Bourque, Alda L; Sullivan, Mary E; Winter, Michael R

    2012-09-01

    The purpose of this study was to determine whether the use of Reiki decreases the amount of meperidine administered to patients undergoing screening colonoscopy. The literature review reveals limited studies to show whether Reiki has been able to decrease the amount of opioid the patient receives during screening colonoscopy. A chart review of 300 patients was conducted to obtain baseline average doses of meperidine patients received as the control. Following the chart review, 30 patients were recruited to the Reiki study. Twenty-five of the study arm patients received Reiki in conjunction with meperidine. Five randomly chosen study arm patients received placebo Reiki in conjunction with meperidine in an attempt to blind the clinicians to the treatment received by the patients. Results showed that there were no significant differences in meperidine administration between the patients in the chart review group (control) and the Reiki group. The study revealed that 16% who received Reiki, together with intravenous administration of conscious sedation, received less than 50 mg of meperidine. All the patients in the chart review group received more than 50 mg of meperidine. Results from this pilot study suggest that there may be a decrease in meperidine needed during screening colonoscopy when patients receive Reiki treatments before the procedure. A larger study powered to detect smaller medication differences is the next step in more accurately determining the effect of Reiki on pain management.

  11. Colonoscopy ‘My Way’: Preparation, Anticoagulants, Antibiotics and Sedation

    Directory of Open Access Journals (Sweden)

    Jerome D Waye

    1999-01-01

    Full Text Available Colonoscopy was introduced in the 1960s. The facility with which this technique is performed has been enhanced by vast improvements in instrumentation. In spite of this, physician attitudes concerning colonoscopy have changed little over the past several decades. The diet for precolonoscopic preparation has not been altered for 30 years. Colonoscopists have a great reluctance to use a new preparation instead of the 4 L electrolyte solution, perhaps because this was such a significant advance in colonoscopic cleansing, its predecessor being castor oil and enemas. Physicians continue to be wary of the patient who is taking acetylsalicylic acid in the absence of any studies that show that this is detrimental for polypectomy. The management of the patient on warfarin anticoagulation remains a subject for debate. As for antibiotic prophylaxis, most endoscopy units do not have a standardized approach, although there are good guidelines that, if followed, should decrease the risk of infective endocarditis. Sedation for the endoscopic examination is usually administered by the colonoscopist, although anesthesiologists may, in some countries (and in some defined areas of the United States be the primary administrators of sedation and analgesia. The present article is a personal approach to the following issues: the preparation of the colon for an examination, current thoughts about anticoagulation and acetylsalicylic acid, antibiotic prophylaxis for colonoscopy and the technique for sedation out of the hospital.

  12. Value of a noise-optimized virtual monoenergetic reconstruction technique in dual-energy CT for planning of transcatheter aortic valve replacement

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Simon S.; Albrecht, Moritz H.; Wichmann, Julian L.; Huesers, Kristina; Scholtz, Jan-Erik; Booz, Christian; Bodelle, Boris; Bauer, Ralf W.; Metzger, Sarah C.; Vogl, Thomas J.; Lehnert, Thomas [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2017-02-15

    To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR). Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F{sub 0}.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale. Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p < 0.001) superior to all VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F{sub 0}.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p < 0.01). Low-keV VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning. (orig.)

  13. Advanced image-based virtual monoenergetic dual-energy CT angiography of the abdomen: optimization of kiloelectron volt settings to improve image contrast

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Moritz H.; Scholtz, Jan-Erik; Huesers, Kristina; Beeres, Martin; Bucher, Andreas M.; Kaup, Moritz; Martin, Simon S.; Fischer, Sebastian; Bodelle, Boris; Bauer, Ralf W.; Lehnert, Thomas; Vogl, Thomas J.; Wichmann, Julian L. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2016-06-15

    To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA. Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M{sub 0}.6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured. Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M{sub 0}.6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M{sub 0}.6 for CHA and SA (P < 0.009). Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality. (orig.)

  14. Virtual Worlds

    OpenAIRE

    Novák, František

    2009-01-01

    The bachelor's thesis is focused on highlighting the development of virtual worlds. The paper summarizes the evolution of virtual reality. Current virtual worlds are compared in fundamental aspects, such as sociology, economics and education. Social sphere describes the interaction in virtual reality and its specialities. Economical sphere is focused on comparison of real and virtual economies, including their economic indicators. Educational sphere describes the sciences, which are best usea...

  15. Colonoscopy Quality Assurance in Ontario: Systematic Review and Clinical Practice Guideline

    Directory of Open Access Journals (Sweden)

    Jill Tinmouth

    2014-01-01

    Full Text Available Colonoscopy is fundamental to the diagnosis and management of digestive diseases and plays a key role in colorectal cancer (CRC screening and diagnosis. Therefore, it is important to ensure that colonoscopy is of high quality. The present guidance document updates the evidence and recommendations in Cancer Care Ontario’s 2007 Colonoscopy Standards, and was conducted under the aegis of the Program in Evidence-Based Care. It is intended to support quality improvement for colonoscopies for all indications, including follow-up to a positive fecal occult blood test, screening for individuals who have a family history of CRC and those at average risk, investigation for symptomatic patients, and surveillance of those with a history of adenomatous polyps or CRC. A systematic review was performed to evaluate the existing evidence concerning the following three key aspects of colonoscopy: physician endoscopist training and maintenance of competency; institutional quality assurance parameters; and colonoscopy quality indicators and auditable outcomes. Where appropriate, indicators were designated quality indicators (where there was sufficient evidence to recommend a specific target and auditable outcomes (insufficient evidence to recommend a specific target, but which should be monitored for quality assurance purposes. The guidance document may be used to support colonoscopy quality assurance programs to improve the quality of colonoscopy regardless of indication. Improvements in colonoscopy quality are anticipated to improve important outcomes in digestive diseases, such as reduction of the incidence of and mortality from CRC.

  16. Editorial: On the Quality of Quality Metrics: Rethinking What Defines a Good Colonoscopy.

    Science.gov (United States)

    Dominitz, Jason A; Spiegel, Brennan

    2016-05-01

    The colonoscopy quality assurance movement has focused on a variety of process metrics, including the adenoma detection rate (ADR). However, the ADR only ascertains whether or not at least one adenoma is identified. Supplemental measures that quantify all neoplasia have been proposed. In this issue of the American Journal of Gastroenterology, Aniwan and colleagues performed tandem screening colonoscopies to determine the adenoma miss rate among high-ADR endoscopists. This permitted validation of supplemental colonoscopy quality metrics. This study highlights potential limitations of ADR and the need for further refinement of colonoscopy quality metrics, although logistic challenges abound.

  17. Value of a noise-optimized virtual monoenergetic reconstruction technique in dual-energy CT for planning of transcatheter aortic valve replacement.

    Science.gov (United States)

    Martin, Simon S; Albrecht, Moritz H; Wichmann, Julian L; Hüsers, Kristina; Scholtz, Jan-Erik; Booz, Christian; Bodelle, Boris; Bauer, Ralf W; Metzger, Sarah C; Vogl, Thomas J; Lehnert, Thomas

    2017-02-01

    To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR). Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale. Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F_0.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning. • VMI+ combines increased contrast with reduced image noise. • VMI+ shows substantially less image noise than traditional VMI. • 40-keV reconstructions show highest SNR/CNR of the aortic and iliofemoral access route. • Observers overall prefer 60 keV VMI+ images. • VMI+ DECT imaging helps improve image quality for TAVR planning.

  18. Haustral loop extraction for CT colonography using geodesics.

    Science.gov (United States)

    Liu, Yongkai; Duan, Chaijie; Liang, Jerome; Hu, Jing; Lu, Hongbing; Luo, Mingyue

    2017-03-01

    The human colon has complex geometric structures because of its haustral folds, which are thin flat protrusions on the colon wall. The haustral loop is the curve (approximately triangular in shape) that encircles the highly convex region of the haustral fold, and is regarded as the natural landmark of the colon, intersecting the longitude of the colon in the middle. Haustral loop extraction can assist in reducing the structural complexity of the colon, and the loops can also serve as anatomic markers for computed tomographic colonography (CTC). Moreover, haustral loop sectioning of the colon can help with the performance of precise prone-supine registration. We propose an accurate approach of extracting haustral loops for CT virtual colonoscopy based on geodesics. First, the longitudinal geodesic (LG) connecting the start and end points is tracked by the geodesic method and the colon is cut along the LG. Second, key points are extracted from the LG, after which paired points that are used for seeking the potential haustral loops are calculated according to the key points. Next, for each paired point, the shortest distance (geodesic line) between the paired points twice is calculated, namely one on the original surface and the other on the cut surface. Then, the two geodesics are combined to form a potential haustral loop. Finally, erroneous and nonstandard potential loops are removed. To evaluate the haustral loop extraction algorithm, we first utilized the algorithm to extract the haustral loops. Then, we let the clinicians determine whether the haustral loops were correct and then identify the missing haustral loops. The extraction algorithm successfully detected 91.87% of all of the haustral loops with a very low false positive rate. We believe that haustral loop extraction may benefit many post-procedures in CTC, such as supine-prone registration, computer-aided diagnosis, and taenia coli extraction.

  19. Errors in CT colonography.

    Science.gov (United States)

    Trilisky, Igor; Ward, Emily; Dachman, Abraham H

    2015-10-01

    CT colonography (CTC) is a colorectal cancer screening modality which is becoming more widely implemented and has shown polyp detection rates comparable to those of optical colonoscopy. CTC has the potential to improve population screening rates due to its minimal invasiveness, no sedation requirement, potential for reduced cathartic examination, faster patient throughput, and cost-effectiveness. Proper implementation of a CTC screening program requires careful attention to numerous factors, including patient preparation prior to the examination, the technical aspects of image acquisition, and post-processing of the acquired data. A CTC workstation with dedicated software is required with integrated CTC-specific display features. Many workstations include computer-aided detection software which is designed to decrease errors of detection by detecting and displaying polyp-candidates to the reader for evaluation. There are several pitfalls which may result in false-negative and false-positive reader interpretation. We present an overview of the potential errors in CTC and a systematic approach to avoid them.

  20. CT仿真内窥镜技术在肝门静脉变异分析中的应用%Application of CT virtual endoscopy in analysis of variations of hepatic portal vein

    Institute of Scientific and Technical Information of China (English)

    庞国栋; 柳澄; 刘学静; 赵芳; 王锡明; 芮军

    2010-01-01

    目的 探讨CT仿真内窥镜(CT virtual endoscopy,CTVE)在精确区分肝门静脉变异类型中的应用价值.方法 对CT门静脉血管成像(CT portal angiology,CTPA)病例中筛选出MIP、VR显示为肝门静脉主干3分叉的15例病人和右支主干显示为3分叉的17例病人用CTVE分析.重点分析3分叉处的管腔结构,例如肝门静脉主干处,右前支-左支(RAPV-LPV)短共干或者是右前支-右后支(RAPV-RPPV)短共干很容易被误认为主干3分叉.以评价CTVE在分辨短共干与3分叉中的价值,纠正原始方法观察分支的欠缺.结果 肝门静脉主干3分叉中60%(9例)经CTVE分析为短RAPV-LPV共干或短RAPV-RPPV共干.17例右支主干3分叉中,35%(6例)为右支主干先分出右后上支,然后分为右后下支和右前支,12%(2例)例为正常解剖(Ⅰ型变异).经CTVE分析后,32例病人只有47%(15例)是真正3分叉,阳性率仅为0.47,统计学有显著差异.结论 由于短共干分支外观上极易与真正3分叉混淆,而CTVE可以真实显示腔内分叉的顺序,从而清晰鉴别3分叉与短共干.此方法可用于肝门静脉解剖的研究,纠正原始方法的不足,获得更加准确的数据.

  1. Time of day variation in polyp detection rate for colonoscopies performed on a 3-hour shift schedule.

    LENUS (Irish Health Repository)

    Munson, Gregory W

    2011-03-01

    Recent research suggests that the colonoscopy polyp detection rate (PDR) varies by time of day, possibly because of endoscopist fatigue. Mayo Clinic Rochester (MCR) schedules colonoscopies on 3-hour shifts, which should minimize fatigue.

  2. 头颈部肿瘤检查中能谱CT虚拟平扫替代常规平扫的可行性研究%Feasibility study on application of gemstone spectral CT material suppressed iodine as virtual non-contrast CT scan in head and neck neoplasms

    Institute of Scientific and Technical Information of China (English)

    杨亮; 罗德红; 赵燕风; 李琳; 林蒙; 冯世超; 周纯武

    2015-01-01

    Objective To evaluate the feasibility of applying spectral CT material suppressed iodine (MSI) imaging as virtual plain CT scan to replace traditional non-contrast (TNC) CT in head and neck neoplasms. Methods A total of 52 patients with initial diagnosis of head and neck neoplasms underwent TNC CT scanning and spectrum mode enhanced scanning in the head and neck with spectral CT. With GSI Volume Viewer software from GE AW4.6 workstation, the enhanced scanning data were processed and MSI images were acquired. The CT values of different tissues (fat, erector spinae, cervical vertebrae, thyroid, and brain parenchyma) and the enhancement rate in erector spinae, carotid sinus were compared between MSI and TNC images. Image quality was objectively evaluated in noise and SNR for MSI and TNC images, while the subjective evaluation included the visibility of lesions, subjective acceptance rate, diagnostic efficacy (with/without lesions or lesion calcification, necrosis). Radiation dose including volume CT dose index (CTDIvol) and effective dose (ED) was compared between MSI and TNC. Results (1) CT values of erector spinae on MSI and TNC imaging were(52 ± 6)and(52 ± 7)HU respectively, and the difference between the two image modes was not significant(t=0.39,P>0.05). CT values on MSI and TNC Imaging were[-74 (-86,-59)HU]and[-79(-73,-61)HU]for fat (Z=-2.71, P0.05). The difference of carotid sinus enhancement rate was significant 5.75(4.70,6.73) and 4.37(3.91,5.61) respectively, Z=-5.50, P0.05).Unacceptable and acceptable cases in imaging quality of MSI were 3 and 49 respectively, while those were 2 and 50 in TNC group. Subjective acceptance rate between MST and TNC images was not significantly different(2=0.01,P>0.05). (5) Diagnostic performance evaluation showed that the consistency of two observers was good in detecting lesions, necrosis and calcification between MSI and TNC image, with K value 0.93, 0.83 and 0.90 respectively (P0.05);脂肪分别为-74(-86,

  3. The completeness rate of colonoscopy in a cohort of unsedated patients

    Directory of Open Access Journals (Sweden)

    Aljebreen Abdulrahman

    2004-01-01

    Full Text Available Background: Colonoscopy is considered a painful procedure requiring routine intravenous sedation, however there are number of potential advantages to performing colonoscopy without sedation. The aim of this study was to determine the effect of unsedated colonoscopy on the success rate of caecal intubation. Patients and methods: All charts of patients who had unsedated colonoscopy from January 2002 to September 2003 were reviewed. Patient characteristics including age, gender, and mode of presentation were collected. The success rate of unsedated colonoscopy was compared with the standard success rate of sedated colonoscopy in the literature. The reasons for incomplete colonoscopy and sites reached were recorded. Results: During the study period, 503 examinations were performed. Patients mean age was 48.5 years, 55.9 % of them were males. Colonic polyps were the predominant abnormal endoscopic finding; occurring in 21.3%. The completion rate in the study population excluding patients with obstructive disease and patients with inadequate preparation was only 67%. Conclusion: In this cohort studiy, sedation probably affects the overall success rate of cecal intubation. A large prospective randomized study comparing sedated with unsedated colonoscopy in terms of completion rate and patient satisfaction is needed

  4. Quality assessment of colonoscopy in Flanders: a voluntary survey among Flemish gastroenterologist.

    Science.gov (United States)

    Macken, E; Vannoote, J; Moreels, T; Peeters, M; Wouters, K

    2015-01-01

    Colonoscopy is an important endoscopic examination for the diagnosis and treatment of pathological conditions of the colon, like polyps and colorectal cancer. However, several factors determine the quality of colonoscopy and thus the quality of polyp and colorectal cancer detection. The Flemish Society of Gastroenterology (VVGE) performed a voluntary on-line registry among its members to identify quality of colonoscopy in Flanders, Belgium. 64 gastroenterologists voluntarily registered 4276 consecutive colonoscopies performed during a 3 month study period. Colonoscopy quality indicators were prospectively collected and analysed. Results showed a low voluntary participation rate (17%), acceptable overall adenoma detection rate of 20,5% and colorectal cancer interval rate of 5,4%. Complications were low (perforation 0,1% and major bleeding 1,5%). The current study showed that in Flanders, Belgium on-line registration of colonoscopy quality indicators is feasible and that quality of colonoscopy in daily practice meets the expectations of (inter)national guidelines. However, further improvement of the registry and an open debate on the quality control of colonoscopy in Flanders is warranted (Belgian Registry B30020096548).

  5. A prospective cohort study evaluating a novel colonoscopy platform featuring full-spectrum endoscopy

    NARCIS (Netherlands)

    Gralnek, Ian Mark; Segol, Ori; Suissa, Alain; Siersema, Peter D.; Carr-Locke, David L.; Halpern, Zamir; Santo, Erwin; Domanov, Svetlana

    2013-01-01

    Background and study aims: Although colonoscopy is the criterion standard for detecting colorectal adenomas and cancers, a significant percentage of adenomas are missed with this technique. We aimed to establish the feasibility, usability, and safety of a novel colonoscopy platform featuring full-sp

  6. Multicenter, randomized, tandem evaluation of EndoRings colonoscopy - results of the CLEVER study

    NARCIS (Netherlands)

    Dik, Vincent K; Gralnek, Ian M; Segol, Ori; Suissa, Alain; Belderbos, Tim D G; Moons, Leon M G; Segev, Meytal; Domanov, Sveta; Rex, Douglas K; Siersema, Peter D

    2015-01-01

    Background and study aims: Adenoma miss rate during colonoscopy has become a widely acknowledged proxy measure for post-colonoscopy colorectal cancer. Among other reasons, this can happen because of inadequate visualization of the proximal aspects of colonic folds and flexures. EndoRings (EndoAid Lt

  7. Multicenter, randomized, tandem evaluation of EndoRings colonoscopy - results of the CLEVER study

    NARCIS (Netherlands)

    Dik, V.K.; Gralnek, I.M.; Segol, O.; Suissa, A.; Belderbos, T.D.; Moons, L.M.; Segev, M.; Domanov, S.; Rex, D.K.; Siersema, P.D.

    2015-01-01

    BACKGROUND AND STUDY AIMS: Adenoma miss rate during colonoscopy has become a widely acknowledged proxy measure for post-colonoscopy colorectal cancer. Among other reasons, this can happen because of inadequate visualization of the proximal aspects of colonic folds and flexures. EndoRings (EndoAid Lt

  8. Can colonoscopy diagnose transmural ischaemic colitis after abdominal aortic surgery? An evidence-based approach

    DEFF Research Database (Denmark)

    Houe, T; Thorböll, J E; Sigild, U;

    2000-01-01

    to assess the diagnostic value of colonoscopy in ischaemic colitis following abdominal aortic surgery, based on a literature review, and to introduce the concept of evidence-based medicine.......to assess the diagnostic value of colonoscopy in ischaemic colitis following abdominal aortic surgery, based on a literature review, and to introduce the concept of evidence-based medicine....

  9. Colonic work-up after incomplete colonoscopy: significant new findings during follow-up

    NARCIS (Netherlands)

    M. Neerincx; J.S. Terhaar sive Droste; C.J. Mulder; M. Räkers; J.F. Bartelsman; R.J. Loffeld; H.A. Tuynman; R.M. Brohet; R.W. van der Hulst

    2010-01-01

    Background and study aims: Cecal intubation is not achieved in 2-23% of colonoscopies. The efforts made by physicians to visualize the remaining colon and the number of missed significant lesions are unknown. This study evaluates 1) the reasons for incomplete colonoscopy, 2) the rates of complete co

  10. No increased risk of perforation during colonoscopy in patients undergoing Nurse Administered Propofol Sedation

    DEFF Research Database (Denmark)

    Okholm, Cecilie; Hadikhadem, Talie; Andersen, Lærke Toftegård

    2013-01-01

    colonoscopies performed with either NAPS or conventional sedation regimes. Material and methods. Data were retrospectively retracted from medical journals from 1 January 2007 to 31 December 2011. All journals were examined and cross-referenced to reveal any perforations. We analyzed all colonoscopies in regard...

  11. Nurse endoscopists perform colonoscopies according to the international standard and with high patient satisfaction

    NARCIS (Netherlands)

    van Putten, P. G.; ter Borg, F.; Adang, R. P. R.; Koornstra, J. J.; Romberg-Camps, M. J. L.; Timmer, R.; Poen, A. C.; Kuipers, E. J.; Van Leerdam, M. E.

    2012-01-01

    Background and study aims: Colonoscopy is increasingly performed by nurse endoscopists. We aimed to assess the endoscopic quality and patient experience of these procedures. Patients and methods: This prospective multicenter study analyzed 100 consecutive colonoscopies each for 10 trained nurse endo

  12. Leadership training to improve adenoma detection rate in screening colonoscopy: A randomised trial

    NARCIS (Netherlands)

    M.F. Kaminski (M.); J. Anderson (John); R.M. Valori (Roland ); E. Kraszewska (Ewa); M. Rupinski (Maciej); J. Pachlewski (Jacek); E. Wronska (Ewa); M. Bretthauer (Michael); S. Thomas-Gibson (Siwan); E.J. Kuipers (Ernst); J. Regula (J.)

    2016-01-01

    textabstractObjective Suboptimal adenoma detection rate (ADR) at colonoscopy is associated with increased risk of interval colorectal cancer. It is uncertain how ADR might be improved. We compared the effect of leadership training versus feedback only on colonoscopy quality in a countrywide randomis

  13. Helical CT in acute lower gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Olivier; Leroy, Christophe; Sergent, Geraldine [Department of Radiology, Hopital Huriez, 1 rue Polonovski, 59037 Lille (France); Bulois, Philippe; Saint-Drenant, Sophie; Paris, Jean-Claude [Department of Gastroenterology, Hopital Huriez, 1 rue Polonovski, 59037 Lille (France)

    2003-01-01

    The purpose of this study was to assess the usefulness of helical CT in depicting the location of acute lower gastrointestinal bleeding. A three-phase helical CT of the abdomen was performed in 24 patients referred for acute lower gastrointestinal bleeding. The diagnosis of the bleeding site was established by CT when there was at least one of the following criteria: spontaneous hyperdensity of the peribowel fat; contrast enhancement of the bowel wall; vascular extravasation of the contrast medium; thickening of the bowel wall; polyp or tumor; or vascular dilation. Diverticula alone were not enough to locate the bleeding site. The results of CT were compared with the diagnosis obtained by colonoscopy, enteroscopy, or surgery. A definite diagnosis was made in 19 patients. The bleeding site was located in the small bowel in 5 patients and the colon in 14 patients. The CT correctly located 4 small bowel hemorrhages and 11 colonic hemorrhages. Diagnosis of the primary lesion responsible for the bleeding was made in 10 patients. Our results suggest that helical CT could be a good diagnostic tool in acute lower gastrointestinal bleeding to help the physician to diagnose the bleeding site. (orig.)

  14. Comparison of detection and miss rates of narrow band imaging, flexible spectral imaging chromoendoscopy and white light at screening colonoscopy: a randomised controlled back-to-back study.

    Science.gov (United States)

    Chung, Su Jin; Kim, Donghee; Song, Ji Hyun; Kang, Hae Yeon; Chung, Goh Eun; Choi, Jeongmin; Kim, Young Sun; Park, Min Jung; Kim, Joo Sung

    2014-05-01

    Virtual chromoendoscopy (CE) is expected to enhance adenoma yield and reduce variation in performance between colonoscopists. This study aimed to compare the efficacy of narrow band imaging (NBI), flexible spectral imaging CE (FICE) and white light (WL) colonoscopy and their impact for less experienced endoscopists. We performed a randomised tandem colonoscopy trial controlling for withdrawal time and bowel preparation. Average-risk adults undergoing screening colonoscopy were enrolled and randomly assigned to first withdrawal with one of the three imaging modalities (NBI (NBI-WL group), FICE (FICE-WL group) and WL (WL-WL group)). Eight colonoscopists were categorised into expert and non-expert subgroups. 1650 subjects (mean age 51.4 years, 63.9% men) were included (550 in each group). Compared with WL, neither NBI nor FICE increased the mean number of adenomas detected per patient (0.37 vs 0.35 and 0.36; p=0.591) or the percentage of patients with adenoma (25.3% vs 24.5% and 23.6%; p=0.753). For all three modalities, expert subgroups had higher yields of adenomas than non-expert subgroups. Learning curves were observed only for non-expert subgroups with all three modalities. The percentage of missed adenomas did not differ between the three groups (20.8% by WL vs 22.9% by NBI and 26.0% by FICE, p=0.300) and was not affected by endoscopists' expertise. Neither NBI nor FICE improved adenoma detection or miss rates, with no difference in diagnostic efficacy between the two systems. Virtual CE had no additional benefits over WL for non-experts. KCT0000570.

  15. Virtual box

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    2007-01-01

    . This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

  16. Combining different methods improves assessment of competence in colonoscopy

    DEFF Research Database (Denmark)

    Konge, Lars; Svendsen, Morten Bo Søndergaard; Preisler, Louise

    2017-01-01

    score calculations were used to explore different combinations of the measures. RESULTS: Twenty physicians were included in the study. The reliability (Cronbach's alpha) were 0.92, 0.57, 0.87 and 0.55 for the subjective score assessed under direct observation, time to cecum, distance between operator......'s hands and colonoscopy progression score, respectively. Equal weight (=25%) to all four methods resulted in a reliability of 0.91 and optimal weighting of the methods (55%, 10%, 25% and 10%, respectively) resulted in a maximum reliability of 0.95. CONCLUSION: Combining subjective expert ratings...

  17. Unsedation colonoscopy can be not that painful: Evaluation of the effect of “Lamaze method of colonoscopy”

    Institute of Scientific and Technical Information of China (English)

    Shao-Ping; Yu; Xiao-Dong; Lin; Guang-Yao; Wu; Song-Hu; Li; Zong-Quan; Wen; Xiao-Hong; Cen; Xian-Guang; Huang; Mei-Ting; Huang

    2015-01-01

    AIM: To evaluate the pain relieving effect of intervention with "Lamaze method of colonoscopy" in the process of colonoscopy.METHODS: Five hundred and eighty-five patients underwent colonoscopy were randomly divided into three groups, Lamaze group, anesthetic group and control group. Two hundred and twenty-four patients of Lamaze group, the "Lamaze method of colonoscopy" were practiced in the process of colonoscopy. The Lamaze method of colonoscopy is modified from the Lamaze method of childbirth, which helped patients to relieve pain through effective breathing control. One hundred and seventy-eight patients in anesthetic group accepted sedation colonoscopy. For 183 patients in control group, colonoscopy was performed without any intervention. The satisfactory of colon cleaning, intestinal lesions, intubation time, success ratio, pain grading and complications were recorded. All data were statistically analyzed.RESULTS: There were no significant differences at base line of the three groups(P > 0.05). Anesthetic group shows advantage in intubation time than the other two groups(P 0.05). The anesthetic group showed an apparent advantage in relieving pain(P < 0.01). Therefore, the "Lamaze method of colonoscopy" performed in colonoscopy could relieve pain effectively comparing with control group(P < 0.05). The patients in anesthetic group had the highest incidence of complications(P < 0.05).CONCLUSION: The performance of the "Lamaze method of colonoscopy" in the process of colonoscopy could relieve patients’ pain, minimize the incidence of complications, and is worthy promotion in clinical practice.

  18. Social disparities in the use of colonoscopy by primary care physicians in Ontario

    Directory of Open Access Journals (Sweden)

    Moineddin Rahim

    2011-09-01

    Full Text Available Abstract Background It is unclear if all persons in Ontario have equal access to colonoscopy. This research was designed to describe long-term trends in the use of colonoscopy by primary care physicians (PCPs in Ontario, and to determine whether PCP characteristics influence the use of colonoscopy. Methods We conducted a population-based retrospective study of PCPs in Ontario between the years 1996-2005. Using administrative data we identified a screen-eligible group of patients aged 50-74 years in Ontario. These patients were linked to the PCP who provided the most continuous care to them during each year. We determined the use of any colonoscopy among these patients. We calculated the rate of colonoscopy for each PCP as the number of patients undergoing colonoscopies per 100 screen eligible patients. Negative binomial regression was used to identify factors associated with the rate of colonoscopy, using generalized estimating equations to account for clustering of patients within PCPs. Results Between 7,955 and 8,419 PCPs in Ontario per year (median age 43 years had at least 10 eligible patients in their practices. The use of colonoscopy by PCPs increased sharply in Ontario during the study period, from a median rate of 1.51 [inter quartile range (IQR 0.57-2.62] per 100 screen eligible patients in 1996 to 4.71 (IQR 2.70-7.53 in 2005. There was substantial variation between PCPs in their use of colonoscopy. PCPs who were Canadian medical graduates and with more years of experience were more likely to use colonoscopy after adjusting for their patient characteristics. PCPs were more likely to use colonoscopy if their patient populations were predominantly women, older, had more illnesses, and if their patients resided in less marginalized neighborhoods (lower unemployment, fewer immigrants, higher income, higher education, and higher English/French fluency. Conclusions There is substantial variation in the use of colonoscopy by PCPs, and this

  19. Social disparities in the use of colonoscopy by primary care physicians in Ontario.

    Science.gov (United States)

    Jacob, Binu J; Baxter, Nancy N; Moineddin, Rahim; Sutradhar, Rinku; Del Giudice, Lisa; Urbach, David R

    2011-09-28

    It is unclear if all persons in Ontario have equal access to colonoscopy. This research was designed to describe long-term trends in the use of colonoscopy by primary care physicians (PCPs) in Ontario, and to determine whether PCP characteristics influence the use of colonoscopy. We conducted a population-based retrospective study of PCPs in Ontario between the years 1996-2005. Using administrative data we identified a screen-eligible group of patients aged 50-74 years in Ontario. These patients were linked to the PCP who provided the most continuous care to them during each year. We determined the use of any colonoscopy among these patients. We calculated the rate of colonoscopy for each PCP as the number of patients undergoing colonoscopies per 100 screen eligible patients. Negative binomial regression was used to identify factors associated with the rate of colonoscopy, using generalized estimating equations to account for clustering of patients within PCPs. Between 7,955 and 8,419 PCPs in Ontario per year (median age 43 years) had at least 10 eligible patients in their practices. The use of colonoscopy by PCPs increased sharply in Ontario during the study period, from a median rate of 1.51 [inter quartile range (IQR) 0.57-2.62] per 100 screen eligible patients in 1996 to 4.71 (IQR 2.70-7.53) in 2005. There was substantial variation between PCPs in their use of colonoscopy. PCPs who were Canadian medical graduates and with more years of experience were more likely to use colonoscopy after adjusting for their patient characteristics. PCPs were more likely to use colonoscopy if their patient populations were predominantly women, older, had more illnesses, and if their patients resided in less marginalized neighborhoods (lower unemployment, fewer immigrants, higher income, higher education, and higher English/French fluency). There is substantial variation in the use of colonoscopy by PCPs, and this variation has increased as the overall use of colonoscopy

  20. Propofol for pediatric colonoscopy: the experience of a large, tertiary care pediatric hospital.

    Science.gov (United States)

    Cohen, Shlomi; Glatstein, Miguel M; Scolnik, Dennis; Rom, Liat; Yaron, Ayala; Otremski, Sorina; Ben-Tov, Amir; Reif, Shimon

    2014-01-01

    Successful colonoscopy includes full visualization of the terminal ileum, especially in inflammatory bowel disease when ileal biopsy is essential. In children, higher levels of anxiety and lack of cooperation often necessitate a deeper level of sedation. The aim of this study was to evaluate the effectiveness of propofol compared with midazolam and fentanyl for colonoscopy, and in accomplishing ileal and cecal intubation in particular. This was a retrospective cohort study comparing the rates of successful colonoscopy in patients receiving propofol with those receiving midazolam/fentanyl. Complete, successful, colonoscopy to the terminal ileum was achieved in 78% of propofol patients compared with 66% of the midazolam/fentanyl group (P=0.004). Endoscopy reaching the cecum, but not the terminal ileum, was achieved in 78% of propofol patients and 66% of midazolam/fentanyl patients. The use of propofol was associated with a statistically significant increase in the rate of successful colonoscopy reaching the terminal ileum.

  1. Cap-assisted colonoscopy and detection of Adenomatous Polyps (CAP) study: a randomized trial.

    Science.gov (United States)

    Pohl, Heiko; Bensen, Steve P; Toor, Arifa; Gordon, Stuart R; Levy, L Campbell; Berk, Brian; Anderson, Peter B; Anderson, Joseph C; Rothstein, Richard I; MacKenzie, Todd A; Robertson, Douglas J

    2015-10-01

    Cap-assisted colonoscopy has improved adenoma detection in some but not other studies. Most previous studies have been limited by small sample sizes and few participating endoscopists. The aim of the current study was to evaluate whether cap-assisted colonoscopy improves adenoma detection in a two-center, multi-endoscopist, randomized trial. Consecutive patients who presented for an elective colonoscopy were randomized to cap-assisted colonoscopy (4-mm cap) or standard colonoscopy performed by one of 10 experienced endoscopists. Primary outcome measures were mean number of adenomas per patient and adenoma detection rate (ADR). Secondary outcomes included procedural measures and endoscopist variation; a logistic regression model was employed to examine predictors of increased detection with cap use. A total of 1113 patients (64 % male, mean age 62 years) were randomized to cap-assisted (n = 561) or standard (n = 552) colonoscopy. The mean number of adenomas detected per patient in the cap-assisted and standard groups was similar (0.89 vs. 0.82; P = 0.432), as was the ADR (42 % vs. 40 %; P = 0.452). Cap-assisted colonoscopy achieved a faster cecal intubation time (4.9 vs. 5.8 minutes; P Cap-assisted colonoscopy resulted in a 20 % increase in ADR for some endoscopists and in a 15 % decrease for others. Individual preference for the cap was an independent predictor of increased adenoma detection in adjusted analysis (P cap-assisted colonoscopy, adenoma detection was not. Cap-assisted colonoscopy may be beneficial for selected endoscopists. clinicalTrials.gov (NCT01935180). © Georg Thieme Verlag KG Stuttgart · New York.

  2. Limited life expectancy among a subgroup of medicare beneficiaries receiving screening colonoscopies.

    Science.gov (United States)

    Mittal, Sahil; Lin, Yu-Li; Tan, Alai; Kuo, Yong-Fang; El-Serag, Hashem B; Goodwin, James S

    2014-03-01

    Life expectancy is an important consideration when assessing appropriateness of preventive programs for older individuals. Most studies on this subject have used age cutoffs as a proxy for life expectancy. We analyzed patterns of utilization of screening colonoscopy in Medicare enrollees by using estimated life expectancy. We used a 5% random national sample of Medicare claims data to identify average-risk patients who underwent screening colonoscopies from 2008 to 2010. Colonoscopies were considered to be screening colonoscopies in the absence of diagnoses for nonscreening indications, which were based on either colonoscopies or any claims in the preceding 3 months. We estimated life expectancies by using a model that combined age, sex, and comorbidity. Among patients who underwent screening colonoscopies, we calculated the percentage of those with life expectancies <10 years. Among the 57,597 Medicare beneficiaries 66 years old or older who received at least 1 screening colonoscopy, 24.8% had an estimated life expectancy of <10 years. There was a significant positive association between total Medicare per capita costs in hospital referral regions and the proportion of patients with limited life expectancies (<10 years) at the time of screening colonoscopy (R = 0.25; P < .001, Pearson correlation test). In a multivariable analysis, men were substantially more likely than women to have limited life expectancy at the time of screening colonoscopy (odds ratio, 2.25; 95% confidence interval, 2.16-2.34). Nearly 25% of Medicare beneficiaries, especially men, had life expectancies <10 years at the time of screening colonoscopies. Life expectancy should therefore be incorporated in decision-making for preventive services. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  3. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  4. The creation of virtual teeth with and without tooth pathology for a virtual learning environment in dental education

    NARCIS (Netherlands)

    de Boer, I.R.; Wesselink, P.R.; Vervoorn, J.M.

    2013-01-01

    Purpose To describe the development and opportunities for implementation of virtual teeth with and without pathology for use in a virtual learning environment in dental education. Material and methods The creation of virtual teeth begins by scanning a tooth with a cone beam CT. The resulting scan co

  5. The creation of virtual teeth with and without tooth pathology for a virtual learning environment in dental education

    NARCIS (Netherlands)

    de Boer, I.R.; Wesselink, P.R.; Vervoorn, J.M.

    2013-01-01

    Purpose To describe the development and opportunities for implementation of virtual teeth with and without pathology for use in a virtual learning environment in dental education. Material and methods The creation of virtual teeth begins by scanning a tooth with a cone beam CT. The resulting scan co

  6. Multidetector CT angiography for acute gastrointestinal bleeding: technique and findings.

    Science.gov (United States)

    Artigas, José M; Martí, Milagros; Soto, Jorge A; Esteban, Helena; Pinilla, Inmaculada; Guillén, Eugenia

    2013-01-01

    Acute gastrointestinal bleeding is a common reason for emergency department admissions and an important cause of morbidity and mortality. Factors that complicate its clinical management include patient debility due to comorbidities; intermittence of hemorrhage; and multiple sites of simultaneous bleeding. Its management, therefore, must be multidisciplinary and include emergency physicians, gastroenterologists, and surgeons, as well as radiologists for diagnostic imaging and interventional therapy. Upper gastrointestinal tract bleeding is usually managed endoscopically, with radiologic intervention reserved as an alternative to be used if endoscopic therapy fails. Endoscopy is often less successful in the management of acute lower gastrointestinal tract bleeding, where colonoscopy may be more effective. The merits of performing bowel cleansing before colonoscopy in such cases might be offset by the resultant increase in response time and should be weighed carefully against the deficits in visualization and diagnostic accuracy that would result from performing colonoscopy without bowel preparation. In recent years, multidetector computed tomographic (CT) angiography has gained acceptance as a first-line option for the diagnosis and management of lower gastrointestinal tract bleeding. In selected cases of upper gastrointestinal tract bleeding, CT angiography also provides accurate information about the presence or absence of active bleeding, its source, and its cause. This information helps shorten the total diagnostic time and minimizes or eliminates the need for more expensive and more invasive procedures.

  7. Role of high definition colonoscopy in colorectal adenomaatous polyp detection

    Institute of Scientific and Technical Information of China (English)

    Tolga Erim; John M Rivas; Evelio Velis; Fernando Castro

    2011-01-01

    AIM: To investigate the rates of polyp detection in a mixed risk population using standard definition (SDC) vs high definition colonoscopes (HDC). METHODS: This was a retrospective cohort comparative study of 3 colonoscopists who each consecutively performed 150 SDC (307, 200 pixel) and 150 HDC (792, 576 pixels) in a community teaching hospital.RESULTS: A total of 900 colonoscopies were evaluated (mean age 56, 46.8% men), 450 with each resolution. Polyps of any type were detected in 46.0% of patients using SDC and 43.3% with HDC (P = 0.42). There was no significant difference between the overall number of polyps, HDC (397) and SDC (410), detected among all patients examined, (P = 0.73). One or more adenomatous polyps were detected in 24.2% of patients with HDC and 24.9% of patients with SDC colonoscopy (P = 0.82). There was no significant difference between HDC (M = 0.41) and SDC (M = 0.42) regarding adenomatous polyp (P = 0.88) or advanced adenoma (P = 0.56) detection rate among all patients examined.CONCLUSION: HDC did not improve yield of adenomatous polyp, advanced adenoma or overall polyp detection in a population of individuals with mixed risk for colorectal cancer.

  8. Effect of music on patients undergoing outpatient colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Matthew L Bechtold; Rodney A Perez; Srinivas R Puli; John B Marshall

    2006-01-01

    AIM: To evaluate the effect of relaxing music during colonoscopy under low-dose conscious sedation, on patient satisfaction, scope insertion time and procedure duration, medication doses, and the perceived adequacy of sedation and scope insertion difficulty on the part of the endoscopist.SETHODS: One hundred and sixty-seven consecutive adult outpatients presenting for routine colonoscopy under low-dose conscious sedation were randomized to undergo their procedures either with music played during the procedure or no music played.RESULTS: There were no statistical differences between the two groups in terms of meperidine dose, midazolam dose, time to reach the cecum, total procedure time,endoscopist assessment of scope insertion difficulty,endoscopist assessment of adequacy of sedation, or the pain experience of the patients during their procedure.The music group did report significantly better overall procedure satisfaction as compared to the non music group on two of our three different scales.CONCLUSION: While music does not result in shortened procedure times, lower doses of sedative medications or perceived patient pain, the patients who have music playing during their procedures report modestly greater satisfaction with their procedures.

  9. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... hold your breath for short periods. A complete scan usually take only 30 seconds to a few ...

  10. Narrative message targets within the decision-making process to undergo screening colonoscopy among Latinos: a qualitative study.

    Science.gov (United States)

    Hennelly, Marie Oliva; Sly, Jamilia R; Villagra, Cristina; Jandorf, Lina

    2015-06-01

    Colorectal cancer (CRC) is a preventable yet leading cause of cancer mortality among Latinos in the USA. Cultural targeting and narrative messaging are two strategies to increase the low screening colonoscopy rates among Latinos. This study identifies key messages for educational interventions aiming to increase screening colonoscopy used among Latinos and proposes a model to understand the relationship between factors involved in colonoscopy decision-making. Individual in-depth interviews were conducted with 12 Latino participants primarily of Puerto Rican descent on the topics of CRC knowledge, barriers and facilitators to colonoscopy use, and the use of narrative in colorectal health messaging. Knowledge about colorectal anatomy and the anesthesia component of colonoscopy procedure is low. Fear of procedure-related pain and fear of treatment-related burden following a cancer diagnosis are significant barriers to colonoscopy. Fear of disease-related suffering and death following a cancer diagnosis and fear of regret are strong facilitators and can be augmented by cancer narratives. Storytelling is commonly used in Latino culture and is an acceptable method to educate the Latino community about CRC screening via colonoscopy. Machismo is a unique barrier to colonoscopy for Latino men via homophobia and reluctance to seek healthcare. A preliminary model to understand factors in colonoscopy decision-making among Latinos is presented. Counseling practices and educational interventions that use culturally targeted narrative health messaging to mediate fears and increase colonoscopy knowledge may increase screening colonoscopy use among Latinos.

  11. A noise-optimized virtual monochromatic reconstruction algorithm improves stent visualization and diagnostic accuracy for detection of in-stent re-stenosis in lower extremity run-off CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); De Cecco, Carlo N.; Yamada, Ricardo T.; Varga-Szemes, Akos; Stubenrauch, Andrew C.; Fuller, Stephen R. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Caruso, Damiano [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Vogl, Thomas J.; Wichmann, Julian L. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Todoran, Thomas M. [Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States)

    2016-12-15

    To evaluate the impact of noise-optimized virtual monochromatic imaging (VMI+) on stent visualization and accuracy for in-stent re-stenosis at lower extremity dual-energy CT angiography (DE-CTA). We evaluated third-generation dual-source DE-CTA studies in 31 patients with prior stent placement. Images were reconstructed with linear blending (F{sub 0}.5) and VMI+ at 40-150 keV. In-stent luminal diameter was measured and contrast-to-noise ratio (CNR) calculated. Diagnostic confidence was determined using a five-point scale. In 21 patients with invasive catheter angiography, accuracy for significant re-stenosis (≥50 %) was assessed at F{sub 0}.5 and 80 keV-VMI+ chosen as the optimal energy level based on image-quality analysis. At CTA, 45 stents were present. DSA was available for 28 stents whereas 12 stents showed significant re-stenosis. CNR was significantly higher with ≤80 keV-VMI+ (17.9 ± 6.4-33.7 ± 12.3) compared to F{sub 0}.5 (16.9 ± 4.8; all p < 0.0463); luminal stent diameters were increased at ≥70 keV (5.41 ± 1.8-5.92 ± 1.7 vs. 5.27 ± 1.8, all p < 0.001) and diagnostic confidence was highest at 70-80 keV-VMI+ (4.90 ± 0.48-4.88 ± 0.63 vs. 4.60 ± 0.66, p = 0.001, 0.0042). Sensitivity, negative predictive value and accuracy for re-stenosis were higher with 80 keV-VMI+ (100, 100, 96.4 %) than F{sub 0}.5 (90.9, 94.1, 89.3 %). 80 keV-VMI+ improves image quality, diagnostic confidence and accuracy for stent evaluation at lower extremity DE-CTA. (orig.)

  12. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  13. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation st...

  14. Virtual Reflexes

    OpenAIRE

    2014-01-01

    Virtual Reality is used successfully to treat people for regular phobias. A new challenge is to develop Virtual Reality Exposure Training for social skills. Virtual actors in such systems have to show appropriate social behavior including emotions, gaze, and keeping distance. The behavior must be realistic and real-time. Current approaches consist of four steps: 1) trainee social signal detection, 2) cognitive-affective interpretation, 3) determination of the appropriate bodily responses, and...

  15. Virtual reality

    OpenAIRE

    Zheng, JM; Chan, KW; Gibson, I.

    1998-01-01

    Virtual reality is still in its infancy. However, many contemporary applications already have proven virtual reality to be indispensable to everyday life. For instance, the technology of virtual product design and manufacturing makes the new products better and cheaper. The applications of VR in medicine allow doctors to diagnose a disease more accurately. Without a doubt, it has and will foster more innovative research and applications. High-resolution, low-lag and low-price systems will be ...

  16. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects......Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...

  17. Scalable, High-performance 3D Imaging Software Platform: System Architecture and Application to Virtual Colonoscopy

    OpenAIRE

    Yoshida, Hiroyuki; Wu, Yin; Cai, Wenli; Brett, Bevin

    2012-01-01

    One of the key challenges in three-dimensional (3D) medical imaging is to enable the fast turn-around time, which is often required for interactive or real-time response. This inevitably requires not only high computational power but also high memory bandwidth due to the massive amount of data that need to be processed. In this work, we have developed a software platform that is designed to support high-performance 3D medical image processing for a wide range of applications using increasingl...

  18. Polyps revealed on a virtual colon voyage: three-dimensional colonoscopy reduces discomfort

    NARCIS (Netherlands)

    Mols, B.

    2003-01-01

    In the western world, colon cancer is the second-largest cause of death from cancer. Since there is a considerable risk that polyps five millimetres and more in diameter may develop into malicious tumours, it is important that they can be detected at an early stage. Until now, this is done by means

  19. Carbon dioxide insufflation during colonoscopy in deeply sedated patients

    Institute of Scientific and Technical Information of China (English)

    Rajvinder Singh; Eu Nice Neo; Nazree Nordeen; Ganesananthan Shanmuganathan; Angelie Ashby; Sharon Drummond; Garry Nind

    2012-01-01

    AIM:To compare the impact of carbon dioxide (CO2) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy.METHODS:Patients referred for colonoscopy were randomized to receive either CO2 or air insufflation during the procedure.Both the colonoscopist and patient were blinded to the type of gas used.During the procedure,insertion and withdrawal times,caecal intubation rates,total sedation given and capnography readings were recorded.The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale (VAS) (0-3).Patients then graded their level of discomfort and abdominal bloating using a similar VAS.Complications during and after the procedure were recorded.RESULTS:A total of 142 patients were randomized with 72 in the air arm and 70 in the CO2 arm.Mean age between the two study groups were similar.Insertion time to the caecum was quicker in the CO2 group at 7.3 min vs 9.9 min with air (P =0.0083).The average withdrawal times were not significantly different between the two groups.Caecal intubation rates were 94.4% and 100% in the air and CO2 groups respectively (P =0.012).The level of discomfort assessed by the nurse was 0.69 (air) and 0.39 (CO2) (P =0.0155) and by the patient 0.82 (air) and 0.46 (CO2) (P =0.0228).The level of abdominal bloating was 0.97 (air) and 0.36 (CO2) (P =0.001).Capnography readings trended to be higher in the CO2 group at the commencement,caecal intubation,and conclusion of the procedure,even though this was not significantly different when compared to readings obtained during air insufflation.There were no complications in both arms.CONCLUSION:CO2 insuffiation during colonoscopy is more efficacious than air,allowing quicker and better cecal intubation rates.Abdominal discomfort and bloating were significantly less with CO2 insufflation.

  20. Virtual Laboratories and Virtual Worlds

    CERN Document Server

    Hut, Piet

    2007-01-01

    Since we cannot put stars in a laboratory, astrophysicists had to wait till the invention of computers before becoming laboratory scientists. For half a century now, we have been conducting experiments in our virtual laboratories. However, we ourselves have remained behind the keyboard, with the screen of the monitor separating us from the world we are simulating. Recently, 3D on-line technology, developed first for games but now deployed in virtual worlds like Second Life, is beginning to make it possible for astrophysicists to enter their virtual labs themselves, in virtual form as avatars. This has several advantages, from new possibilities to explore the results of the simulations to a shared presence in a virtual lab with remote collaborators on different continents. I will report my experiences with the use of Qwaq Forums, a virtual world developed by a new company (see http://www.qwaq.com)

  1. Urinary excretion of polyethylene glycol 3350 during colonoscopy preparation

    DEFF Research Database (Denmark)

    Rothfuss, K. S.; Bode, J.C.; Stange, E.F.

    2006-01-01

    . In patients with inflammatory bowel disease (IBD), intestinal permeability and PEG absorption were previously reported to be higher than in normal subjects. In the current study, we investigated the absorption of PEG 3350 in patients undergoing routine gut lavage. METHODS AND RESULTS: Urine specimens were...... collected for 8 hours in 24 patients undergoing bowel cleansing with PEG 3350 for colonoscopy. The urinary excretion of PEG 3350, measured by size exclusion chromatography, ranged between 0.01 and 0.51 % of the ingested amount, corresponding to 5.8 and 896 mg in absolute amounts, respectively. Mean PEG...... excretion in patients with impaired mucosa such as inflammation or ulceration of the intestine (0.24 % +/- 0.19, n = 11) was not significantly higher (p = 0.173) compared to that in subjects with macroscopically normal intestinal mucosa (0.13 % +/- 0.13, n = 13). CONCLUSION: The results indicate...

  2. Postpolypectomy bleeding in patients undergoing colonoscopy on uninterrupted clopidogrel therapy.

    Science.gov (United States)

    Singh, Mandeep; Mehta, Nilesh; Murthy, Uma K; Kaul, Vivek; Arif, Asma; Newman, Nancy

    2010-05-01

    The risk of postpolypectomy bleeding (PPB) in patients undergoing colonoscopy on uninterrupted clopidogrel therapy has not been established. To assess the PPB rate and outcome and identify risk factors associated with PPB in patients taking clopidogrel. Single-center, retrospective study. Demographics, clinical parameters, polyp characteristics, polypectomy techniques, and postpolypectomy events in the groups were compared by univariate analysis. Stepwise logistic regression analyses identified independent risk factors associated with PPB. Veterans Affairs Medical Center. A total of 142 patients (375 polypectomies) taking clopidogrel (cases) and 1243 patients (3226 polypectomies) not taking clopidogrel (controls). None. Postpolypectomy bleeding, hospitalization, and mortality. The immediate (intraprocedural) bleeding rate was similar in the 2 groups (2.1% vs 2.1%). Delayed (postprocedural) PPB rate was higher in the group taking clopidogrel (3.5% vs 1.0%, P = .02). Delayed bleeding of significance requiring hospitalization and transfusion/intervention was also higher in patients taking clopidogrel (2.1% vs 0.4%, P = .04). The length of hospital stay and interventions for PPB were comparable between the 2 groups. There was no mortality. Concomitant use of clopidogrel and aspirin/other nonsteroidal anti-inflammatory drugs (odds ratio 3.7; 95% CI, 1.6-8.5) and the number of polyps removed (OR 1.3; 95% CI, 1.2-1.4) were the only significant risk factors associated with PPB. Clopidogrel alone was not an independent risk factor for PPB. Retrospective study and small number of patients with PPB. The PPB rate is significantly higher in patients undergoing polypectomy while taking clopidogrel and concomitant aspirin/nonsteroidal anti-inflammatory drugs; however, the risk is small and the outcome is favorable. Routine cessation of clopidogrel in patients before colonoscopy/polypectomy is not necessary. 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby

  3. Informed consent in colonoscopy: A comparative analysis of 2 methods.

    Science.gov (United States)

    Sanguinetti, J M; Lotero Polesel, J C; Iriarte, S M; Ledesma, C; Canseco Fuentes, S E; Caro, L E

    2015-01-01

    The manner in which informed consent is obtained varies. The aim of this study is to evaluate the level of knowledge about colonoscopy and comparing 2 methods of obtaining informed consent. A comparative, cross-sectional, observational study was conducted on patients that underwent colonoscopy in a public hospital (Group A) and in a private hospital (Group B). Group A received information verbally from a physician, as well as in the form of printed material, and Group B only received printed material. A telephone survey was carried out one or 2 weeks later. The study included a total of 176 subjects (group A [n=55] and group B [n=121]). As regards education level, 69.88% (n=123) of the patients had completed university education, 23.29% (n= 41) secondary level, 5.68% (n=10) primary level, and the remaining subjects (n=2) had not completed any level of education. All (100%) of the subjects knew the characteristics of the procedure, and 99.43% were aware of its benefits. A total of 97.7% received information about complications, 93.7% named some of them, and 25% (n=44) remembered major complications. All the subjects received, read, and signed the informed consent statement before the study. There were no differences between the groups with respect to knowledge of the characteristics and benefits of the procedure, or the receipt and reading of the consent form. Group B responded better in relation to complications (P=.0027) and group A had a better recollection of the major complications (P<.0001). Group A had a higher number of affirmative answers (P<.0001). The combination of verbal and written information provides the patient with a more comprehensive level of knowledge about the procedure. Copyright © 2014 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

  4. Evaluation of magnifying colonoscopy in the diagnosis of serrated polyps

    Institute of Scientific and Technical Information of China (English)

    Shinya Ishigooka; Masahito Nomoto; Nobuyuki Obinata; Yoshichika Oishi; Yoshinori Sato; Satoko Nakatsu; Midori Suzuki

    2012-01-01

    AIM:To elucidate the colonoscopic features of serrated lesions of the colorectum using magnifying colonoscopy.METHODS:Broad division of serrated lesions of the colorectum into hyperplastic polyps (HPs),traditional serrated adenomas (TSAs),and sessile serrated adenomas/polyps (SSA/Ps) has been proposed on the basis of recent molecular biological studies.However,few reports have examined the colonoscopic features of these divisions,including magnified colonoscopic findings.This study examined 118 lesions excised in our hospital as suspected serrated lesions after magnified observation between January 2008 and September 2011.Patient characteristics (sex,age),conventional colonoscopic findings (location,size,morphology,color,mucin) and magnified colonoscopic findings (pit pattern diagnosis) were interpreted by five colonoscopists with experience in over 1000 colonoscopies,and were compared with histopathological diagnoses.The pit patterns were categorized according to Kudo's classification,but a more detailed investigation was also performed using the subclassification [type Ⅱ-Open (type Ⅱ-O),type Ⅱ-Long (type Ⅱ-L),or type Ⅳ-Serrated (type Ⅳ-S)] proposed by Kimura T and Yamano H.RESULTS:Lesions comprised 23 HPs (23/118:19.5%),39 TSAs (39/118:33.1%:with cancer in one case),50 SSA/Ps (50/118:42.4%:complicated with cancer in three cases),and six others (6/118:5.1%).We excluded six others,including three regular adenomas,one hamartoma,one inflammatory polyp,and one juvenile polyp for further analysis.Conventional colonoscopy showed that SSA/Ps were characterized as larger in diameter than TSAs and HPs (SSA/P vs HP,13.62 ± 8.62 mm vs 7.74 ± 3.24 mm,P < 0.001; SSA/Ps vs TSA,13.62 ±8.62 mm vs 9.89 ± 5.73 mm,P < 0.01); common in the right side of the colon [HPs,30.4% (7/23):TSAs,20.5%(8/39):SSA/P,84.0% (42/50),P < 0.001]; fiat-elevated lesion [HPs,30.4% (7/23):TSAs,5.1% (2/39):SSA/Ps,90.0% (45/50),P < 0.001]; normal-colored or pale

  5. Modern CT and PET/CT imaging of the liver; Moderne CT- und PET/CT-Bildgebung der Leber

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, J.; Heusner, T.A.; Riegger, C.; Reichelt, D.; Kuhlemann, J.; Antoch, G.; Blondin, D. [Medizinische Fakultaet, Heinrich-Heine-Universitaet Duesseldorf, Institut fuer Diagnostische und Interventionelle Radiologie, Duesseldorf (Germany)

    2011-08-15

    Computed tomography (CT) is now widely available and represents an important and rapid method for the diagnostics of acute liver disease, characterization of focal liver lesions, planning of interventional therapy measures and postintervention control. In recent years CT has not become less important despite the increasing value of magnetic resonance imaging (MRI). By the use of different contrast medium phases good characterization of space-occupying lesions can be achieved. For the diagnostics of hepatocellular carcinoma (HCC) a triphasic examination protocol should always be implemented. The introduction of dual energy CT increased the sensitivity of imaging of hypervascularized and hypovascularized liver lesions and by the use of virtual native imaging it has become possible to avoid additional native imaging which reduces the x-ray exposition of patients. Positron emission tomography (PET) has an advantage for imaging in oncology because nearly the complete body of the patient can be screened and this is the main indication for PET/CT (whole-body staging). For purely hepatic problems 18F-fluorodeoxyglucose (FDG)-PET/CT using diagnostic CT data has a higher precision than CT alone but is inferior to MRI. (orig.) [German] Die Computertomographie (CT) ist heute breit verfuegbar und stellt eine wichtige und schnelle Methode zur Diagnostik akuter Lebererkrankungen, der Artdiagnostik fokaler Leberlaesionen und der Planung interventioneller Therapiemassnahmen sowie der postinterventionellen Kontrolle dar. In den letzten Jahren hat die CT trotz des zunehmenden Stellenwerts der Magnetresonanztomographie (MRT) nicht an Bedeutung verloren. Durch den Einsatz unterschiedlicher Kontrastmittelphasen kann meist eine gute Charakterisierung von Raumforderungen erfolgen. Bei der Diagnostik des hepatozellulaeren Karzinoms (HCC) sollte beispielsweise immer ein triphasisches Untersuchungsprotokoll angewendet werden. Mit Einfuehrung der Dual-energy-CT hat die Sensitivitaet in der

  6. Virtual Acoustics

    Science.gov (United States)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  7. CT findings of pulmonary aspergillosis

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Jung Eun; Im, Jung Gi; Goo, Jin Mo; Kim, Hong Dae; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-10-15

    The fungus aspergillus can cause a variety of pulmonary disorders. Aspergilloma is a noninvasive aspergillus colonization of virtually any type of preexisting pulmonary cavity or cystic space. Invasive pulmonary aspergillosis is serious, usually fatal infection in patients being treated with immunosuppressants or who have chronic debilitating disease. Allergic bronchopulmonary aspergillosis is characterized clinically by asthma, blood and sputum eosinophilia and positive immunologic reaction to aspergillus antigen. Awareness of the radiographic and CT findings of pulmonary aspergillosis is important in making the diagnosis of aspergillus-caused pulmonary disorders. In this pictorial essay, we illustrated various radiological findings of pulmonary aspergillosis focused on CT findings correlated with gross pathologic specimens.

  8. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    an interesting platform for further development including virtual materiality and agency. If we choose to proceed along this line – some of our steps would include attention to the following points: 1. Working with virtual realities first of all undermines a pure realist conceptualization of materiality. We need......There are two questions that feed the curiosity of this paper: a theoretical question connected to the conceptualization of materiality across the real/virtual divide and an empirical question connected to the understanding of virtual experiences in children’s lives when studied in relation...... as their recounts of them and 3. the consumption of other media products like movies, reality shows, YouTube videos etc. How do we theorize ‘matter’ in such dimensions? Is it possible to theorize virtual matter as ‘materiality’ in line with any real life materiality? What conceptualization will help us understand...

  9. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...... for performing these projects. This paper compares best practices with practiced practices for virtual projects and discusses ways to bridge the gap between them. We have studied eleven virtual projects in five Danish organizations and compared them with a predefined list of best practices compiled from...... that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects...

  10. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity......-systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...

  11. Propofol for sedation during colonoscopy- A survey of a Cochrane review

    DEFF Research Database (Denmark)

    Høj, Anders Thorsmark

    2010-01-01

    The Cochrane collaboration metaanalysis of propofol use during colonoscopy found a faster patient recovery, higher patient satisfaction and unchanged complication rate compared to traditional sedatives. Patient groups consisted mostly of ASA I-II-patients, therefore the study is inconclusive...

  12. Effect of oxygen on tachycardia and arterial oxygen saturation during colonoscopy

    DEFF Research Database (Denmark)

    Holm, C; Christensen, M; Schulze, S

    1999-01-01

    through nasal prongs (2 L/min), and 20 patients breathed room air during colonoscopy. All patients were given conscious sedation and were monitored with a pulse oximeter during colonoscopy. MAIN OUTCOME MEASURES: Tachycardia (pulse rate>100 min(-1)) and arterial oxygen desaturation (SpO2... colonoscopy. RESULTS: There were no differences in the incidence of tachycardia or mean heart rate during endoscopy between the two groups, and no patient developed symptomatic cardiac arrhythmias or hypotensive episodes. 10 patients in the room air compared with none in the oxygen treatment group (p = 0.......0004) had one or more episodes during which arterial oxygen saturation fell below 90% during colonoscopy, and mean oxygen saturation was higher in the oxygen treatment group than in the room air group (p tachycardia...

  13. Current sedation and monitoring practice for colonoscopy: an International Observational Study (EPAGE)

    DEFF Research Database (Denmark)

    Froehlich, F; Harris, JK; Wietlisbach, V;

    2006-01-01

    in endoscopy centers internationally. PATIENTS AND METHODS: This observational study included consecutive patients referred for colonoscopy at 21 centers in 11 countries. Endoscopists reported sedation and monitoring practice, using a standard questionnaire for each patient. RESULTS: 6004 patients were......BACKGROUND AND STUDY AIMS: Sedation and monitoring practice during colonoscopy varies between centers and over time. Knowledge of current practice is needed to ensure quality of care and help focus future research. The objective of this study was to examine sedation and monitoring practice...... included in this study, of whom 53 % received conscious/moderate sedation during colonoscopy, 30 % received deep sedation, and 17 % received no sedation. Sedation agents most commonly used were midazolam (47 %) and opioids (33 %). Pulse oximetry was done during colonoscopy in 77 % of patients, blood...

  14. Stress perception among patients in pre-colonoscopy period and those undergoing chemotherapy treatment

    Directory of Open Access Journals (Sweden)

    Graziela de Souza Alves da Silva

    2015-05-01

    Full Text Available Objective: comparing the perception of stress among patients with colorectal cancer undergoing chemotherapy with those in pre-colonoscopy period. Methods: a comparative descriptive study developed with 144 people receiving chemotherapy and 100 patients in the pre-colonoscopy period, using biosocial and clinical data, Stress Assessment Tool and Perceived Stress Scale. Results: a predominance of females (73%, aged over 65 (50% were predominant for the pre-colonoscopy period patients. In patients receiving chemotherapy, gender parity with ages ranging from 40-64 years (68.1% was observed. Pre-colonoscopy patients showed higher perceived stress compared to those receiving chemotherapy (p <0.001. Conclusion: the phase of diagnostic definition represents greater stress to patients in comparison to period of treatment, even despite the characteristic manifestations of chemotherapy.

  15. Patient acceptance of MR colonography with improved fecal tagging versus conventional colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Achiam, M.P. [Department of Diagnostic Radiology and Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark)], E-mail: achiam1@dadlnet.dk; Logager, V.; Chabanova, E.; Thomsen, H.S.; Rosenberg, J. [Department of Diagnostic Radiology and Department of Surgical Gastroenterology D, Copenhagen University Hospital Herlev, Herlev Ringvej, DK-2730 Herlev (Denmark)

    2010-01-15

    Objective: Conventional colonoscopy (CC) is the gold standard for colonic examinations. However, patient acceptance is not high. Patient acceptance is influenced by several factors, notably anticipation and experience. This has led to the assumption that patient acceptance would be higher in non-invasive examinations such as MR/CT colonography (MRC/CTC) and perhaps even higher without bowel preparation. The purpose of this study was to evaluate patient acceptance of MRC with fecal tagging versus CC. Materials and methods: In a 14-month period, all patients first-time referred to our department for CC were asked to participate in the study. Two days prior to MRC, patients ingested an oral contrast mixture (barium/ferumoxsil) together with four meals each day. Standard bowel purgation was performed before CC. Before and after MRC and CC a number of questions were addressed. Results: Sixty-four (34 men, 30 women) patients referred for CC participated in the study. 27% had some discomfort ingesting the contrast mixture, and 49% had some discomfort with the bowel purgation. As a future colonic examination preference, 71% preferred MRC, 13% preferred CC and 15% had no preference. If MRC was to be performed with bowel purgation, 75% would prefer MRC, 12% would prefer CC and 12% had no preference. Conclusion: This study shows that there is a potential gain in patient acceptance by using MRC for colonic examination, since MRC is considered less painful and less unpleasant than CC. In addition, the results indicate that patients in this study prefer fecal tagging instead of bowel purgation.

  16. Neighborhood socioeconomic status and use of colonoscopy in an insured population--a retrospective cohort study.

    Directory of Open Access Journals (Sweden)

    Chyke A Doubeni

    Full Text Available BACKGROUND: Low-socioeconomic status (SES is associated with a higher colorectal cancer (CRC incidence and mortality. Screening with colonoscopy, the most commonly used test in the US, has been shown to reduce the risk of death from CRC. This study examined if, among insured persons receiving care in integrated healthcare delivery systems, differences exist in colonoscopy use according to neighborhood SES. METHODS: We assembled a retrospective cohort of 100,566 men and women, 50-74 years old, who had been enrolled in one of three US health plans for ≥1 year on January 1, 2000. Subjects were followed until the date of first colonoscopy, date of disenrollment from the health plan, or December 31, 2007, whichever occurred first. We obtained data on colonoscopy use from administrative records. We defined screening colonoscopy as an examination that was not preceded by gastrointestinal conditions in the prior 6-month period. Neighborhood SES was measured using the percentage of households in each subject's census-tract with an income below 1999 federal poverty levels based on 2000 US census data. Analyses, adjusted for demographics and comorbidity index, were performed using Weibull regression models. RESULTS: The average age of the cohort was 60 years and 52.7% were female. During 449,738 person-years of follow-up, fewer subjects in the lowest SES quartile (Q1 compared to the highest quartile (Q4 had any colonoscopy (26.7% vs. 37.1% or a screening colonoscopy (7.6% vs. 13.3%. In regression analyses, compared to Q4, subjects in Q1 were 16% (adjusted HR = 0.84, 95% CI: 0.80-0.88 less likely to undergo any colonoscopy and 30%(adjusted HR = 0.70, CI: 0.65-0.75 less likely to undergo a screening colonoscopy. CONCLUSION: People in lower-SES neighborhoods are less likely to undergo a colonoscopy, even among insured subjects receiving care in integrated healthcare systems. Removing health insurance barriers alone is unlikely to eliminate

  17. Etiology and significance of incidentally detected focal colonic uptake on FDG PET/CT

    Directory of Open Access Journals (Sweden)

    Nilendu C Purandare

    2012-01-01

    Full Text Available Background: Incidental colonic uptake of 18F-flurodeoxyglucose (FDG is not an infrequent finding encountered during whole body positron emission tomography (PET imaging. Almost all studies on this topic are in Western populations, which have a markedly different epidemiological profile for colorectal premalignant and malignant conditions as compared to that of the Indian subcontinent. Aim: The purpose of this study was to assess the etiology of incidentally detected focal FDG uptake in the colon by comparing it with colonoscopy and histopathology. Materials and Methods : Electronic medical records of patients who underwent FDG PET/computed tomography (CT at our institution for a 2΍-year period from January 2009 to July 2011 were reviewed. There were 32 out of 9000 (0.35% patients whose PET/CT reports mentioned incidental focal colonic FDG uptake, of which 24 patients subsequently underwent colonoscopy. Lesions which appeared neoplastic on colonoscopy were confirmed with histopathology obtained after biopsy or surgery. Colonoscopy and pathology findings were considered as gold standard. Results: Among the 24 patients who underwent a colonoscopy, 3 patients had normal findings (12.5%. A positive colonoscopy was noted in 21 patients (87.5% with the lesion coinciding with the location described in the PET/CT report. Adenomatous polyps were detected in 12 patients (37.5%, whereas in 8 patients (25% malignant lesions were confirmed [adenocarcinoma n = 5, non-Hodgkin′s lymphoma (NHL n = 2, malignant melanoma n = 1]. In one patient, colonic uptake was diagnosed as inflammatory. The mean standardized uptake value max (SUV max for the 12 premalignant lesions was 16.9 ± 9.6 (range 7.5-37.4 and the mean SUV max for the 8 malignant lesions was 12.9 ± 5.5 (range 6.7-21.6. The difference in SUV max between the premalignant adenomatous polyps and the malignant lesions was not statistically significant ( P = 0.316. Conclusions: Our study shows that a

  18. Entornos virtuales tridimensionales de aprendizaje

    OpenAIRE

    Lizarralde, Francisco Ángel José

    2016-01-01

    En el presente trabajo se intenta establecer un marco de evaluación de las capacidades que ofrecen los entornos virtuales 3D, para la enseñanza de temas específicos de la currícula básica de Ingeniería, en particular, aquellos relacionados con la simulación numérica de sistemas dinámicos. Este marco de evaluación es utilizado posteriormente para analizar un conjunto de entornos virtuales 3D, elegidos especialmente por sus características distintivas. Asimismo, se plantea la utilización didáct...

  19. Virtual cancer image data warehouse.

    Science.gov (United States)

    Oyama, H; Wakao, F; Mishina, T; Lu, Y; Honjo, A

    1997-01-01

    We previously developed a system with which we have created more than 100 virtual cancer images from CT or MR data of individual patients with cancer (Cancer Edutainment Virtual Reality Theater: CEVRT). These images can be used to help explain procedures, findings, etc. to the patient, to obtain informed consent, to simulate surgery, and to estimate cancer invasion to surrounding organs. We recently developed a web-based object-oriented database both to access these cancer images and to register medical images at international research sites via the Internet. In this report, we introduce an international medical VR data warehouse created using an object-oriented database.

  20. Pros and cons of colonoscopy in management of acute lower gastrointestinal bleeding

    Institute of Scientific and Technical Information of China (English)

    Dekey Y Lhewa; Lisa L Strate

    2012-01-01

    Acute lower gastrointestinal bleeding (LGIB) is a frequent gastrointestinal cause of hospitalization,particularly in the elderly,and its incidence appears to be on the rise.Endoscopic and radiographic measures are available for the evaluation and treatment of LGIB including flexible sigmoidoscopy,colonoscopy,angiography,radionuclide scintigraphy and multi-detector row computed tomography.Although no modality has emerged as the gold standard in the management of LGIB,colonoscopy is the current preferred initial test for the majority of the patients presenting with hematochezia felt to be from a colon source.Colonoscopy has the ability to diagnose all sources of bleeding from the colon and,unlike the radiologic modalities,does not require active bleeding at the time of the examination.In addition,therapeutic interventions such as cautery and endoclips can be applied to achieve hemostasis and prevent recurrent bleeding.Studies suggest that colonoscopy,particularly when performed early in the hospitalization,can decrease hospital length of stay,rebleeding and the need for surgery.However,results from available small trials are conflicting and larger,multicenter studies are needed.Compared to other management options,colonoscopy is a safe procedure with complications reported in less than 2% of patients,including those undergoing urgent examinations.The requirement of bowel preparation (typically 4 or more liters of polyethylene glycol),the logistical complexity of coordinating after-hours colonoscopy,and the low prevalence of stigmata of hemorrhage complicate the use of colonoscopy for LGIB,particularly in urgent situations.This review discusses the above advantages and disadvantages of colonoscopy in the management of acute lower gastrointestinal bleeding in further detail.

  1. A modular simulation framework for colonoscopy using a new haptic device.

    Science.gov (United States)

    Hellier, David; Samur, Evren; Passenger, Josh; Spälter, Ulrich; Frimmel, Hans; Appleyard, Mark; Bleuler, Hannes; Ourselin, Sébastien

    2008-01-01

    We have developed a multi-threaded framework for colonoscopy simulation utilising OpenGL with an interface to a real-time prototype colonoscopy haptic device. A modular framework has enabled us to support multiple haptic devices and efficiently integrate new research into physically based modelling of the colonoscope, colon and surrounding organs. The framework supports GPU accelerated algorithms as runtime modules, allowing the real-time calculations required for haptic feedback.

  2. Association between the location of colon polyps at baseline and surveillance colonoscopy: a retrospective study

    Directory of Open Access Journals (Sweden)

    Ana Oliveira

    Full Text Available Introduction: Several factors are used to stratify the probability of polyp recurrence. However, there are no studies correlating the location of the initial polyps and the recurrent ones. The aim of this study was to verify whether the polyp location at the surveillance colonoscopy was correlated with the location of the previously excised polyps at the baseline colonoscopy. Methods: A retrospective study of patients submitted to colonoscopy with presence and excision of all polyps, followed by a surveillance colonoscopy. Polyp location was divided into proximal/distal to splenic flexure and rectum. Characteristics and recurrent rates at the same colon location were also evaluated. Results: Out of the 346 patients who underwent repeated colonoscopy, 268 (77.4% had at least 1 polyp detected. For all the segments there was an increased risk of recurrent polyps in the same location and it was about four times higher in proximal (OR 3.5; CI 2.1-6.0 and distal colon segments (OR 3.8; CI 2.1-6.8, followed by three times higher in the rectum (OR 2.6; CI 1.5-4.6. No difference was found between the rates of recurrence at the same segment, taking into consideration the polyp morphology, size, polypectomy technique employed and histological classification. Conclusion: There seems to be a significant association between polyp location at baseline and surveillance colonoscopy.

  3. Improving the Quality of Colonoscopy Bowel Preparation Using an Educational Video

    Directory of Open Access Journals (Sweden)

    Sateesh R Prakash

    2013-01-01

    Full Text Available Colonoscopy is the preferred modality for colon cancer screening. A successful colonoscopy requires proper bowel preparation. Adequate bowel preparation continues to remain a limiting factor. One hundred thirty-three patients scheduled for an outpatient colonoscopy were prospectively randomized in a single-blinded manner to video or nonvideo group. In addition to written bowel preparation instructions, patients in the video group viewed a brief instructional video. Quality of colon preparation was measured using the Ottawa Bowel Preparation Quality scale, while patient satisfaction with preparation was evaluated using a questionnaire. Statistical analyses were used to evaluate the impact of the instructional colonoscopy video. There were significant differences in the quality of colonoscopy preparation between the video and the nonvideo groups. Participants who watched the video had better preparation scores in the right colon (P = 0.0029, mid-colon (P = 0.0027, rectosigmoid (P = 0.0008, fluid content (P = 0.03 and aggregate score (median score 4 versus 5; P = 0.0002. There was no difference between the two groups with regard to patient satisfaction. Income, education level, sex, age and family history of colon cancer had no impact on quality of colonoscopy preparation or patient satisfaction. The addition of an instructional bowel preparation video significantly improved the quality of colon preparation.

  4. Improving the quality of colonoscopy bowel preparation using an educational video.

    Science.gov (United States)

    Prakash, Sateesh Reddy; Verma, Siddharth; McGowan, John; Smith, Betsy E; Shroff, Anjali; Gibson, Gregory H; Cheng, Michael; Lowe Ii, Douglas; Gopal, Kavitha; Mohanty, Smruti R

    2013-12-01

    Colonoscopy is the preferred modality for colon cancer screening. A successful colonoscopy requires proper bowel preparation. Adequate bowel preparation continues to remain a limiting factor. One hundred thirty-three patients scheduled for an outpatient colonoscopy were prospectively randomized in a single-blinded manner to video or nonvideo group. In addition to written bowel preparation instructions, patients in the video group viewed a brief instructional video. Quality of colon preparation was measured using the Ottawa Bowel Preparation Quality scale, while patient satisfaction with preparation was evaluated using a questionnaire. Statistical analyses were used to evaluate the impact of the instructional colonoscopy video. There were significant differences in the quality of colonoscopy preparation between the video and the nonvideo groups. Participants who watched the video had better preparation scores in the right colon (P=0.0029), mid-colon (P=0.0027), rectosigmoid (P=0.0008), fluid content (P=0.03) and aggregate score (median score 4 versus 5; P=0.0002). There was no difference between the two groups with regard to patient satisfaction. Income, education level, sex, age and family history of colon cancer had no impact on quality of colonoscopy preparation or patient satisfaction. The addition of an instructional bowel preparation video significantly improved the quality of colon preparation.

  5. Characterizing Online Narratives About Colonoscopy Experiences: Comparing Colon Cancer "Screeners" Versus "Survivors".

    Science.gov (United States)

    McQueen, Amy; Arnold, Lauren D; Baltes, Michael

    2015-08-01

    Effective screening can reduce colorectal cancer mortality; however, screening uptake is suboptimal. Patients' stories about various health topics are widely available online and in behavioral interventions and are valued by patients. Although these narratives may be promising strategies for promoting cancer screening behavior, scant research has compared the influence of different role models. This study involving content analysis of online stories aimed to (a) describe the content of online experiential narratives about colonoscopy; (b) compare narratives from individuals who had a colonoscopy and either had colon cancer (survivors) or did not have colon cancer (screeners); and (c) generate hypotheses for future studies. The authors identified 90 narratives eligible for analysis from 15 websites. More stories were about White patients, men, and routine (vs. diagnostic) colonoscopy. A higher-than-expected number of narratives reported a family history of colorectal cancer or polyps (20%) and a colorectal cancer diagnosis (47%). Colorectal cancer survivor (vs. screener) stories were longer, mentioned symptoms and diagnostic reasons for getting a colonoscopy more often, and described the colonoscopy procedure or referred to it as easy or painless less often. Future studies should examine the effects of the role model's personal characteristics and the colonoscopy test result on reader's perceptions and intentions to have a colorectal cancer screening.

  6. Evaluating screening colonoscopy quality in an uninsured urban population following patient navigation.

    Science.gov (United States)

    Naylor, Keith; Fritz, Cassandra; Polite, Blase; Kim, Karen

    2017-03-01

    Patient navigation (PN) increases screening colonoscopy completion in minority and uninsured populations. However, colonoscopy quality is under-reported in the setting of PN and quality indicators have often failed to meet benchmark standards. This study investigated screening colonoscopy quality indicators after year-one of a PN initiative targeting the medically uninsured. This was a retrospective analysis of 296 outpatient screening colonoscopies. Patients were 45 to 75 years of age with no history of bowel cancer, inflammatory bowel disease, or colorectal surgery. The screening colonoscopy quality indicators: adenoma detection rate (ADR), cecal intubation rate (CIR), and bowel preparation quality were compared in 89 uninsured Federally Qualified Health Center (FQHC) patients who received PN and 207 University Hospital patients who received usual care. The FQHC PN and University Hospital cohorts were similar in female sex (69% vs. 70%; p = 0.861) and African American race (61% vs. 61%; p = 0.920). The FQHC PN cohort was younger (57 years vs. 60 years; p bench-mark standards for high-quality screening colonoscopy and were equivalent to those observed in an insured University Hospital patient population.

  7. Physician Perceptions on Colonoscopy Quality: Results of a National Survey of Gastroenterologists

    Directory of Open Access Journals (Sweden)

    Ziad F. Gellad

    2014-01-01

    Full Text Available Background. Quality indicators for colonoscopy have been developed, but the uptake of these metrics into practice is uncertain. Our aims were to assess physician perceptions regarding colonoscopy quality measurement and to quantify the perceived impact of quality measurement on clinical practice. Methods. We conducted in-person interviews with 15 gastroenterologists about their perceptions regarding colonoscopy quality. Results from these interviews informed the development of a 34-question web-based survey that was emailed to 1,500 randomlyselected members of the American College of Gastroenterology. Results. 160 invitations were undeliverable, and 167 out of 1340 invited physicians (12.5% participated in the survey. Respondents and nonrespondents did not differ in age, sex, practice setting, or years since training. 38.8% of respondents receive feedback on their colonoscopy quality. The majority of respondents agreed with the use of completion rate (90% and adenoma detection rate (83% as quality indicators but there was less enthusiasm for withdrawal time (61%. 24% of respondents reported usually or always removing diminutive polyps solely to increase their adenoma detection rate, and 20% reported prolonging their procedure time to meet withdrawal time standards. Conclusions. A minority of respondents receives feedback on the quality of their colonoscopy. Interventions to increase continuous quality improvement in colonoscopy screening are needed.

  8. Screening CT Colonography: Multicenter Survey of Patient Experience, Preference, and Potential Impact on Adherence

    Science.gov (United States)

    Pooler, B. Dustin; Baumel, Mark J.; Cash, Brooks D.; Moawad, Fouad J.; Riddle, Mark S.; Patrick, Amy M.; Damiano, Mark; Lee, Matthew H.; Kim, David H.; del Rio, Alejandro Muñoz; Pickhardt, Perry J.

    2013-01-01

    OBJECTIVE Prior research indicates CT colonography (CTC) would be a cost-effective colorectal cancer (CRC) screening test if widespread availability were to increase overall CRC screening adherence rates. The primary aims of this multicenter study were to evaluate patient experience and satisfaction with CTC screening and compare preference against screening colonoscopy. MATERIALS AND METHODS A 12-question survey instrument measuring pretest choice, experience, and satisfaction was given to a consecutive cohort of adults undergoing CTC screening in three disparate screening settings: university academic center, military medical center, and community practice. The study cohort was composed of individuals voluntarily participating in clinical CTC screening programs. RESULTS A total of 1417 patients responded to the survey. The top reasons for choosing CTC for screening included “noninvasiveness” (68.0%), “avoidance of sedation/anesthesia” (63.1%), “ability to drive after the test” (49.2%), “avoidance of optical colonoscopy risks” (46.9%), and “identifying abnormalities outside the colon” (43.3%). Only 7.2% of patients reported pain during the CTC examination and only 2.5% reported greater than moderate discomfort. Of 441 patients who had experienced both CTC and optical colonoscopy, 77.1% preferred CTC and 13.8% preferred optical colonoscopy. Of all patients, 29.6% indicated that they may not have undergone optical colonoscopy screening if CTC were not available. Of all patients, 92.9% labeled their overall experience with CTC as “excellent” or “good,” and 93.0% indicated they would choose CTC for their next screening. CONCLUSION Respondents reported a very high satisfaction level with CTC, and those who had experienced both modalities indicated a preference for CTC over optical colonoscopy. These results suggest that CTC has the potential to increase adherence to CRC screening guidelines if widely available. PMID:22623549

  9. 小儿腺样体肥大的螺旋CT仿真内窥镜(CTVE)成像技术探讨%Discussion about CT Virtual Endoscopy(CTVE) Imaging Technology of Pediatric Adenoidal Hypertrophy

    Institute of Scientific and Technical Information of China (English)

    栾海; 王春生; 李宏伟

    2011-01-01

    Objective To investigate how to make the inspecting technology better to further improve the adenoids hypertrophy patients' 3D image quality. Methods CTVE technology was used to conduct an examination toward 32 cases of adenoid hypertrophy. The scanning parameters were adjusted properly, then after controlling the imaging direction, the 3D images of the nasopharynx were formed in the virtual NE's front and rear position. The result of CT inspection were calculated and compared with that of CTVE technology or NE. Results All the adenoid hypertrophy patients were inspected by CTVE in this group. The statistical consistent analysis was performed about the posterior naris obstruction's extent inspected by CTVE at the front position and NE respectively, withχ2 value of 4.000, P value of 0.261 (>0.05) by Mateχ2 Test, and the value of 0.806(>0.75) by Consistency Test kappa. Two groups of the statistics had a good consistency, and the diagnosis with various methods had no significant difference. Conclusion When inspecting the adenoidal hypertrophy patients by CTVE, the scanning parameters have to be adjusted properly, and the image direction has to be controlled, then the 3D reconstruction image can be achieved, which plays an important role in clinic.%目的:探讨如何改进螺旋CT仿真内窥镜检查技术,以提高腺样体肥大患者三维成像质量.方法:利用螺旋CT仿真内窥镜技术对32例腺样体肥大患者进行检查,合理调整扫描参数、控制成像方向,形成三维鼻咽前视位及后视位仿真内镜影像,将螺旋CT检查情况与术中或鼻内窥镜结果进行统计比较.结果:本组腺样体肥大患者全部完成CTVE检查,CTVE前视位与NE检查后鼻孔阻塞程度结果进行统计学一致性分析,配对卡方x2=4.000,P=0.261(>0.05),Kappa检验值为0.806(>0.75).提示2组数据一致性较好,诊断方法无显著性差异.结论:利用螺旋CT仿真内窥镜技术对腺样体肥大患者检查时合理调整

  10. Virtual Poetry.

    Science.gov (United States)

    Gyori, Ladislao Pablo

    1996-01-01

    Presents a manifesto proposing the creation of a new kind of poetry--virtual poetry--that exists only in electronic space and computer networks. States that this new poetry is interactive, animated, hyper-linked, and navigational. (PA)

  11. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity...... the design and activity of the advanced virtual worlds and role-playing games, then the empirical research on the actors’ activity, while they are acting, is an important precondition to it. A step towards the conception of such a designing strategy for virtual exploratories is currently pursued...

  12. Virtual Workshop

    DEFF Research Database (Denmark)

    Buus, Lillian; Bygholm, Ann

    In relation to the Tutor course in the Mediterranean Virtual University (MVU) project, a virtual workshop “Getting experiences with different synchronous communication media, collaboration, and group work” was held with all partner institutions in January 2006. More than 25 key-tutors within MVU...... participated from different institutions in the workshop. The result of the workshop was experiences with different communication tools and media. Facing the difficulties and possibilities in collaborateting virtually concerned around group work and development of a shared presentation. All based on getting...... experiences for the learning design of MVU courses. The workshop intented to give the participants the possibility to draw their own experiences with issues on computer supported collaboration, group work in a virtual environment, synchronous and asynchronous communication media, and different perspectives...

  13. Virtual Teams.

    Science.gov (United States)

    Geber, Beverly

    1995-01-01

    Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

  14. Applicable observation of butorphanol in painless colonoscopy examination

    Directory of Open Access Journals (Sweden)

    Li Xuefeng

    2017-01-01

    Full Text Available Objective:To summarize the clinical effect of butorphanol compound propofol in painless colonoscopy examination and its feasibility.Methods:100 colonoscopy examination patients (56 males and 44 females aged from 19 to 60 years old registered between August, 2016 and September, 2016 in the endoscopy center of our hospital were randomly selected. ASA classification is I or II level. Their body weight ranged from 55 kg to 75kg. They were randomly divided into two groups and each group included 50 cases. All patients went through conventional ambrosia and liquid fasting for 8 hours before the anesthesia and they drank magnesium sulfate liquid of 2500ml to clean their gastrointestinal tracts.After patients entered the operating room, their veins of upper limb were opened so as to monitor their HR, MAP and SPO2. After that, butorphanol of 20μg/kg was injected to patients of the experimental group while normal saline of the same amount of was injected to patients of the contrast group. After 60 seconds, propofol of 1~2 mg/kg was injected to both groups by the way of intravenous injection. The enteroscopy examination was started after patients had no eyelash reflection. Besides, actual application dose of propofol was adjusted according to clinical indications of patients and the adjusting frequency each time was controlled between 30 milligrams and 50 milligrams until the completion of the examination. SPSS 22.0 statistical software was used to analyze and handle research data of this group. Results:Anesthesia effect: The difference of inter-group comparison showed no statistical significance (P>0.05. The intra-group comparison and the inter-group comparison show that the difference in terms of changes of HR, MAP and SpO2 of patients in two groups before and after the anesthesia had no statistical significance (P>0.05.The awakening time, VAS score, postoperative vomiting times and the occurrence rate of respiratory depression of the observation group

  15. Virtual reality and virtual bodies

    Science.gov (United States)

    Richards, Catherine; Korba, Larry W.; Shaw, Christopher D.; Green, Mark

    1994-04-01

    There are many ways to produce the sense of `presence' or telepresence in the user of virtual reality. For example attempting to increase the realism of the visual environment is a commonly accepted strategy. In contrast, this paper explores a way for the user to feel present in an unrealistic virtual body. It investigates an unusual approach, proprioceptive illusions. Proprioceptive or body illusions are used to generate and explore the experience of virtuality and presence outside of the normal body limits. These projects are realized in art installations.

  16. Panoramic endoluminal display with minimal image distortion using circumferential radial ray-casting for primary three-dimensional interpretation of CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Soo; Park, Seong Ho; Kim, Namkug; Lee, Jeongjin; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea); Kim, Jin Kook [INFINITT Co., Ltd., Seoul (Korea); Park, Beom Jin [Korea University College of Medicine, Department of Radiology, Seoul (Korea); Kim, Young Jun [Konkuk University School of Medicine, Konkuk University Hospital, Department of Radiology, Seoul (Korea); Lee, Min Woo [Konkuk University School of Medicine, Konkuk University Hospital, Department of Radiology, Seoul (Korea); Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology, Seoul (Korea)

    2009-08-15

    The purpose of this study was to develop a panoramic endoluminal display technique, the band view, which causes minimal image distortion, and to determine its feasibility as a time-efficient primary three-dimensional review method of CT colonography (CTC). Image distortion was compared between the band view and four other three-dimensional review modes using ten 10-mm and ten 20-mm electronically generated polyps. Diagnostic performance and interpretation time were compared between the band view and the conventional endoluminal view by two independent readers in 52 patients who underwent CTC and colonoscopy on the same day. Mean image distortion index values, in which 1 indicates no distortion and the larger value represents greater distortion, were significantly smaller with the band view (1.03 and 1.01 for 10-mm and 20-mm polyps, respectively) than with the filet view (1.65 and 1.55) or the virtual colon dissection (3.27 and 3.85) (P{<=}0.004). The sensitivity and specificity for detecting adenomatous polyps {>=}6 mm did not differ, but the mean interpretation time was significantly shorter with the band view than with the conventional endoluminal view by 1.8 and 4.5 minutes in readers 1 and 2, respectively (P<0.0001). The band view can be a time-efficient alternative for primary three-dimensional review of CTC. (orig.)

  17. Virtual Specimens

    Science.gov (United States)

    de Paor, D. G.

    2009-12-01

    Virtual Field Trips have been around almost as long as the Worldwide Web itself yet virtual explorers do not generally return to their desktops with folders full of virtual hand specimens. Collection of real specimens on fields trips for later analysis in the lab (or at least in the pub) has been an important part of classical field geoscience education and research for generations but concern for the landscape and for preservation of key outcrops from wanton destruction has lead to many restrictions. One of the author’s favorite outcrops was recently vandalized presumably by a geologist who felt the need to bash some of the world’s most spectacular buckle folds with a rock sledge. It is not surprising, therefore, that geologists sometimes leave fragile localities out of field trip itineraries. Once analyzed, most specimens repose in drawers or bins, never to be seen again. Some end up in teaching collections but recent pedagogical research shows that undergraduate students have difficulty relating specimens both to their collection location and ultimate provenance in the lithosphere. Virtual specimens can be created using 3D modeling software and imported into virtual globes such as Google Earth (GE) where, they may be linked to virtual field trip stops or restored to their source localities on the paleo-globe. Sensitive localities may be protected by placemark approximation. The GE application program interface (API) has a distinct advantage over the stand-alone GE application when it comes to viewing and manipulating virtual specimens. When instances of the virtual globe are embedded in web pages using the GE plug-in, Collada models of specimens can be manipulated with javascript controls residing in the enclosing HTML, permitting specimens to be magnified, rotated in 3D, and sliced. Associated analytical data may be linked into javascript and localities for comparison at various points on the globe referenced by ‘fetching’ KML. Virtual specimens open up

  18. Patient Satisfaction With Propofol for Outpatient Colonoscopy: A Prospective, Randomized, Double-Blind Study.

    Science.gov (United States)

    Padmanabhan, Anantha; Frangopoulos, Christoforos; Shaffer, Lynn E T

    2017-10-01

    Previous literature has shown that propofol has ideal anesthetic properties for patients undergoing colonoscopy, a common procedure at outpatient surgery centers. However, there is a paucity of information regarding patient satisfaction with propofol. The aim of this study was to evaluate patient satisfaction with propofol compared with nonpropofol (fentanyl/midazolam) anesthesia for outpatient colonoscopies. Safety and complications were secondary end points. This study was a double-blind, randomized, parallel-group controlled clinical trial (NCT 02937506). This study was conducted at a single ambulatory surgery center at an urban teaching community health system. Patients were scheduled for outpatient colonoscopy. Those with high-risk cardiac or pulmonary disease were excluded. Anesthesia personnel administered either fentanyl/midazolam (n = 300) or propofol (n = 300) for sedation during outpatient colonoscopy. A single, highly experienced endoscopist performed all colonoscopies. The primary outcomes measured were patient satisfaction (5-point Likert scale) and procedure complications. Data were collected on the day of endoscopy by the nursing staff of the postanesthesia care unit. A subinvestigator blinded to the randomization called patients 24 to 72 hours after discharge to obtain data on postprocedure problems and status of resumption of normal activities. Analysis was intention-to-treat. Fewer patients who received propofol remembered being awake during the procedure (2% vs 17% for fentanyl, p propofol (p propofol group (2.7% vs 11.7%, p propofol over a combination of fentanyl/midazolam as their anesthetic for outpatient colonoscopies. From a patient and provider perspective, propofol appears to be superior to fentanyl/midazolam for outpatient colonoscopy. See Video Abstract at http://links.lww.com/DCR/A445.

  19. Use of automated irrigation pumps improves quality of bowel preparation for colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Sujan Ravi; Rana Sabbagh; Fadi Antaki

    2016-01-01

    AIM: To evaluate the effectiveness of automated irrigation pumps(AIPs) in improving the quality of the bowel preparation and the yield of colonoscopy.METHODS: A retrospective observational study was conducted at a single medical center. Outpatient colonoscopies performed during a 4-mo time period when AIPs were not in use, were compared to colonoscopies performed during control period. The main outcomes measured were quality of bowel preparation, procedures aborted due to poor preparation, recommendations to repeat at short interval due to suboptimal bowel preparation and adenoma detection rates.RESULTS: One thousand and thirty-seven colonoscopies were included. A higher proportion of cases did not achieve a satisfactory bowel preparation when AIPs were not used(24.4% vs 10.3%, P < 0.01). The number of procedures aborted due to inadequate preparation was not significantly different, however a repeat procedure at a short interval was recommended in a higher proportion of cases when AIPs were not used(21.3% vs 6.9%, P < 0.01). Good or excellent preparation was 2.91(95%CI: 2.04-4.15) times more likely when AIPs were used. Detection of polyps and adenomas was not significantly different.CONCLUSION: AIP use during colonoscopy results in a higher proportion of colonic preparation rated as satisfactory, although polyp detection rate is not significantly affected. Recommendations for repeat colonoscopy at shorter interval significantly decrease with the use of AIPs. This study supports the use of the irrigation pumps in endoscopy units to improve the quality of colonoscopy.

  20. Ascaris lumbricoides: To Expect the Unexpected during a Routine Colonoscopy.

    Science.gov (United States)

    Kanneganti, Kalyan; Makker, Jasbir S; Remy, Prospere

    2013-01-01

    Ascaris lumbricoides is a common nematode infecting humans worldwide with increased prevalence in tropical and subtropical areas of less developed countries. Recently, it has been estimated that over one billion individuals are infected with ascariasis worldwide with 7% in USA. Although most of these cases are due to increasing immigration and travel outside America it is worth recognizing that prevalence of ascariasis is high in southeastern parts of USA due to their temperate climate. Infections of A. lumbricoides are largely asymptomatic, and hence a large population of people carrying this worm remains undetected for years until they develop some symptoms. Due to a large group of asymptomatic individuals with intestinal ascariasis, these worms are occasionally and unexpectedly identified during routine endoscopic procedures. Here, we present a case of an intestinal ascariasis found during routine colonoscopy in an African-American man from the Bronx with perianal itching. He denied any history of travel outside USA but reported frequent visits to South Carolina. This case illustrates the fact that ascariasis should be suspected even if immigration or travel outside USA is not involved. It should be suspected even in cases of travel within USA to the south east where endemic cases are reported.

  1. Ascaris lumbricoides: To Expect the Unexpected during a Routine Colonoscopy

    Directory of Open Access Journals (Sweden)

    Kalyan Kanneganti

    2013-01-01

    Full Text Available Ascaris lumbricoides is a common nematode infecting humans worldwide with increased prevalence in tropical and subtropical areas of less developed countries. Recently, it has been estimated that over one billion individuals are infected with ascariasis worldwide with 7% in USA. Although most of these cases are due to increasing immigration and travel outside America it is worth recognizing that prevalence of ascariasis is high in southeastern parts of USA due to their temperate climate. Infections of A. lumbricoides are largely asymptomatic, and hence a large population of people carrying this worm remains undetected for years until they develop some symptoms. Due to a large group of asymptomatic individuals with intestinal ascariasis, these worms are occasionally and unexpectedly identified during routine endoscopic procedures. Here, we present a case of an intestinal ascariasis found during routine colonoscopy in an African-American man from the Bronx with perianal itching. He denied any history of travel outside USA but reported frequent visits to South Carolina. This case illustrates the fact that ascariasis should be suspected even if immigration or travel outside USA is not involved. It should be suspected even in cases of travel within USA to the south east where endemic cases are reported.

  2. Virtual instrumentation: Introduction of virtual

    OpenAIRE

    Ödlund, Erika

    2007-01-01

    The Large Hadron Collider (LHC) is the next large particle accelerator developed at CERN, constructed to enable studies of particles. The acceleration of the particles is carried out using magnets operating at about 1.9 K, a temperature achieved by regulating flow of superfluid helium. For economical reasons, control of the helium flow is based on feedback of virtual flow meter (VFT) estimates instead of real instrumentation. The main purpose of this work is to develop a virtual flow meter wi...

  3. Information seeking and anxiety among colonoscopy-naïve adults: Direct-to-colonoscopy vs traditional consult-first pathways

    Science.gov (United States)

    Silvester, Jocelyn A; Kalkat, Harmandeep; Graff, Lesley A; Walker, John R; Singh, Harminder; Duerksen, Donald R

    2016-01-01

    AIM To investigate the effects of direct to colonoscopy pathways on information seeking behaviors and anxiety among colonoscopy-naïve patients. METHODS Colonoscopy-naïve patients at two tertiary care hospitals completed a survey immediately prior to their scheduled outpatient procedure and before receiving sedation. Survey items included clinical pathway (direct or consult), procedure indication (cancer screening or symptom investigation), telephone and written contact from the physician endoscopist office, information sources, and pre-procedure anxiety. Participants reported pre-procedure anxiety using a 10 point scale anchored by “very relaxed” (1) and “very nervous” (10). At least three months following the procedure, patient medical records were reviewed to determine sedative dose, procedure indications and any adverse events. The primary comparison was between the direct and consult pathways. Given the very different implications, a secondary analysis considering the patient-reported indication for the procedure (symptoms or screening). Effects of pathway (direct vs consult) were compared both within and between the screening and symptom subgroups. RESULTS Of 409 patients who completed the survey, 34% followed a direct pathway. Indications for colonoscopy were similar in each group. The majority of the participants were women (58%), married (61%), and internet users (81%). The most important information source was family physicians (Direct) and specialist physicians (Consult). Use of other information sources, including the internet (20% vs 18%) and Direct family and friends (64% vs 53%), was similar in the Direct and Consult groups, respectively. Only 31% of the 81% who were internet users accessed internet health information. Most sought fundamental information such as what a colonoscopy is or why it is done. Pre-procedure anxiety did not differ between care pathways. Those undergoing colonoscopy for symptoms reported greater anxiety [mean 5.3, 95

  4. CDC Group EO-4 and Candida tropicalis Peritonitis in a Patient on Peritoneal Dialysis after Upper Endoscopy, Colonoscopy and Coil Embolization of the Gastroduodenal Artery

    Science.gov (United States)

    Gayen, Shameek; Ziemba, Yonah; Jaiswal, Shikha; Frank, Adam; Brahmbhatt, Yasmin

    2016-01-01

    Peritoneal dialysis (PD) is an excellent form of renal replacement therapy for many patients with end-stage renal disease (ESRD). Over 10,000 patients receive PD in the United States [United States Renal Data System: 2015 USRDS Annual Data Report: Epidemiology of Kidney Disease in the United States, 2015]. PD has superior outcomes compared to hemodialysis in the first 2 years of ESRD [Sinnakirouchenan and Holley: Adv Chronic Kidney Dis 2011;18: 428-432]. However, peritonitis is a known complication and may result in significant morbidity and necessitate transition to hemodialysis, which increases medical costs [Holley and Piraino: Semin Dial 1990;3: 245-248]. We report the first case of a PD patient who underwent endoscopy, colonoscopy and CT angiogram with coil embolization for gastrointestinal bleeding without antibiotic prophylaxis and subsequently developed CDC group EO-4 organism and fungal peritonitis.

  5. CDC Group EO-4 and Candida tropicalis Peritonitis in a Patient on Peritoneal Dialysis after Upper Endoscopy, Colonoscopy and Coil Embolization of the Gastroduodenal Artery

    Directory of Open Access Journals (Sweden)

    Shameek Gayen

    2016-11-01

    Full Text Available Peritoneal dialysis (PD is an excellent form of renal replacement therapy for many patients with end-stage renal disease (ESRD. Over 10,000 patients receive PD in the United States [United States Renal Data System: 2015 USRDS Annual Data Report: Epidemiology of Kidney Disease in the United States, 2015]. PD has superior outcomes compared to hemodialysis in the first 2 years of ESRD [Sinnakirouchenan and Holley: Adv Chronic Kidney Dis 2011;18: 428–432]. However, peritonitis is a known complication and may result in significant morbidity and necessitate transition to hemodialysis, which increases medical costs [Holley and Piraino: Semin Dial 1990;3: 245–248]. We report the first case of a PD patient who underwent endoscopy, colonoscopy and CT angiogram with coil embolization for gastrointestinal bleeding without antibiotic prophylaxis and subsequently developed CDC group EO-4 organism and fungal peritonitis.

  6. Barriers and facilitators associated with colonoscopy completion in individuals with multiple chronic conditions: a qualitative study

    Directory of Open Access Journals (Sweden)

    Sultan S

    2017-05-01

    Full Text Available Shahnaz Sultan,1–4 Melissa R Partin,1,2 Phalgoon Shah,5 Jennifer LeLaurin,4 Ivette Magaly Freytes,4 Chandylen L Nightingale,6 Susan F Fesperman,4 Barbara A Curbow,7 Rebecca J Beyth3,4,8 1Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System, 2Department of Medicine, University of Minnesota, Minneapolis, MN, 3Department of Medicine, University of Florida College of Medicine, Gainesville, FL, 4Center of Innovation on Disability and Rehabilitation Research, North Florida/South Georgia Veterans Health System, Gainesville, FL, 5Department of Medicine, Tripler Army Medical Center, Honolulu, HI, 6Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem NC, 7Department of Community and Behavioral Health, University of Maryland, College Park, MD, 8Geriatric Research, Education and Clinical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA Background: A recommendation to undergo a colonoscopy, an invasive procedure that requires commitment and motivation, planning (scheduling and finding a driver and preparation (diet restriction and laxative consumption, may be uniquely challenging for individuals with multiple chronic conditions (MCCs. This qualitative study aimed to describe the barriers and facilitators to colonoscopy experienced by such patients.Materials and methods: Semistructured focus groups were conducted with male Veterans who were scheduled for outpatient colonoscopy and either failed to complete the procedure or completed the examination. Focus group recordings were transcribed and analyzed by an inductive grounded approach using constant comparative analysis.Results: Forty-four individuals aged 51–83 years participated in this study (23 adherent and 21 nonadherent. Participants had an average of 7.4 chronic conditions (range 2–14. The five most common chronic conditions were hypertension (75%, hyperlipidemia (75

  7. Diagnostic study of multi-slice spiral CT 3D reconstruction and virtual endoscope technology on diagnosing ear temporal diseases%多层螺旋CT三维重建及仿真内镜技术对耳颞部疾病的诊断研究

    Institute of Scientific and Technical Information of China (English)

    张金玲; 李延皎; 陈鹏; 王海波; 李金平; 刘白鹭

    2012-01-01

    Objective To investigate the diagnostic value of multi-slice spiral CT (MSCT) 3D reconstruction and virtual endoscope technology on ear temporal diseases.Methods One hundred and forty patients suspected with ear temporal diseases were examined with MSCT,and all the scanned images were 3D reconstructed and processed by virtual endoscopy.Results In 140 patients,97 cases were detected with ear temporal disease,including 58 cases with acute and chronic otitis media,20 cases with artificially cochlear placement evaluation,2 cases with concha and middle ear malformations and 17 cases with temporal bone injury.MSCT 3D reconstruction and virtual endoscope technology could clearly show the location,scope and form of the lesions and structure relationships with nearby tissues.Conclusions MSCT 3D reconstruction and virtual endoscope technology have important value on diagnosing ear temporal diseases.%目的 探讨多层螺旋CT (MSCT)三维重建及仿真内镜技术对耳颞部疾病的诊断价值.方法 对140例怀疑有耳颞部疾病患者行颞骨MSCT检查,对所有扫描图像进行三维重建及仿真内镜处理.结果 140例患者中97例检出耳颞部疾病,其中58例急、慢性中耳炎,20例人工耳蜗植入术前进行评价,2例外中耳部发育畸形,17例颞骨外伤.MSCT三维重建及仿真内镜技术能够清晰显示病变的位置、范围、形态及与周围组织结构的关系.结论 MSCT三维重建及仿真内镜技术对耳颞部疾病的诊断具有重要价值.

  8. Virtual care

    DEFF Research Database (Denmark)

    Kamp, Annette; Aaløkke Ballegaard, Stinne

    point out how issues of trust and surveillance, which are always negotiated in care relations, are in fact accentuated in this kind of virtual care work. Moreover, we stress that the contemporary institutional context, organization and time schedules have a vast impact on the practices developed....... of retrenchment, promising better quality, empowerment of citizens and work that is smarter and more qualified. Through ethnographic field studies we study the introduction of virtual home care in Danish elderly care, focusing on the implications for relational work and care relations. Virtual home care entails...... the performance of specific home care services by means of video conversations rather than physical visits in the citizens’ homes. As scholars within the STS tradition maintain, technologies do not simply replace a human function; they rather transform care work, redistributing tasks between citizens, technology...

  9. Virtual Tower

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, R.A. [Sandia National Labs., Albuquerque, NM (United States). Security Engineering Dept.

    1997-08-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems.

  10. Virtual Violence.

    Science.gov (United States)

    2016-08-01

    In the United States, exposure to media violence is becoming an inescapable component of children's lives. With the rise in new technologies, such as tablets and new gaming platforms, children and adolescents increasingly are exposed to what is known as "virtual violence." This form of violence is not experienced physically; rather, it is experienced in realistic ways via new technology and ever more intense and realistic games. The American Academy of Pediatrics continues to be concerned about children's exposure to virtual violence and the effect it has on their overall health and well-being. This policy statement aims to summarize the current state of scientific knowledge regarding the effects of virtual violence on children's attitudes and behaviors and to make specific recommendations for pediatricians, parents, industry, and policy makers.

  11. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  12. Developing a tool to preserve eye contact with patients undergoing colonoscopy for pain monitoring

    Directory of Open Access Journals (Sweden)

    Niv Y

    2012-08-01

    Full Text Available Yaron Niv, Yossi TalDepartment of Gastroenterology, Rabin Medical Center, Tel Aviv University, IsraelAbstract: Colonoscopy has become the leading procedure for early detection and prevention of colorectal cancer. Patients’ experience of colonic endoscopic procedures is scarcely reported, even though it is considered a major factor in colorectal cancer screening participation. Pain due to air inflation or stretching the colon with an endoscope is not rare during examination and may be the main obstacle to cooperation and participation in a screening program. We propose a four-stage study for developing a tool dedicated to pain monitoring during colonoscopy, as follows: (1 comparison of patient, nurse, and endoscopist questionnaire responses about patient pain and technical details of the procedure using the PAINAD tool during colonoscopy; (2 observation of the correlation between patients’ facial expressions and other parameters (using the short PAINAD; (3 development of a device for continuous monitoring of the patient’s facial expression during the procedure; (4 assessment of the usability of such a tool and its contribution to the outcomes of colonoscopy procedures. Early intervention by the staff performing the procedure, in reaction to alerts encoded by this tool, may prevent adverse events during the procedure.Keywords: pain scoring, colonoscopy, pain monitoring, facial expression

  13. Quality Assessment of Colonoscopy Reporting: Results from a Statewide Cancer Screening Program

    Directory of Open Access Journals (Sweden)

    Jun Li

    2010-01-01

    Full Text Available This paper aimed to assess quality of colonoscopy reports and determine if physicians in practice were already documenting recommended quality indicators, prior to the publication of a standardized Colonoscopy Reporting and Data System (CO-RADS in 2007. We examined 110 colonoscopy reports from 2005-2006 through Maryland Colorectal Cancer Screening Program. We evaluated 25 key data elements recommended by CO-RADS, including procedure indications, risk/comorbidity assessments, procedure technical descriptions, colonoscopy findings, specimen retrieval/pathology. Among 110 reports, 73% documented the bowel preparation quality and 82% documented specific cecal landmarks. For the 177 individual polyps identified, information on size and morphology was documented for 87% and 53%, respectively. Colonoscopy reporting varied considerately in the pre-CO-RADS period. The absence of key data elements may impact the ability to make recommendations for recall intervals. This paper provides baseline data to assess if CO-RADS has an impact on reporting and how best to improve the quality of reporting.

  14. COLONOSCOPY COMPLICATIONS IN THE ELDERLY: the impact of age and multimorbidity

    Directory of Open Access Journals (Sweden)

    Francine de Cristo STEIN

    2013-12-01

    Full Text Available Context Age has been considered an independent risk factor for colonoscopy complications, especially when associated with multimorbidity. Objectives The primary objective was to verify the relationships between age, multimorbidity and colonoscopy complications in the elderly. Methods A retrospective cohort including patients of 60 years or older who had undergone a colonoscopy. Data relating to age, multimorbidities according to the cumulative illness scale for geriatrics and the Charlson index and complications related to bowel preparation and procedure (sedation and exam were collected. Results Of the 207 patients (mean age 70.47 ± 7.04 with appropriate indication for colonoscopy according to the American Society for Gastrointestinal Endoscopy, 43 (20.77% patients had some colonoscopy complications: 1 (0.48% with the sedation (apnea, 4 (1.93% with the procedure (abdominal pain and bacteremia and 38 (18.35% with the bowel preparation (acute renal failure, hypotension. Individuals ≥80 years had an RR = 3.4 (1.2-10.1, P = 0.025, and those with a Charlson index 3 had an RR = 5.2 (1.6-16.8, P = 0.006, for complications. The cumulative illness rating scale for geriatrics was not associated with complications (P = 0.45. Conclusion There was a significant risk of complications in ≥80 years and in the group with a Charlson index 3. The cumulative illness rating scale for geriatrics was not a good predictor of risk in this sample.

  15. CO_2 insufflation for potentially difficult colonoscopies:Efficacy when used by less experienced colonoscopists

    Institute of Scientific and Technical Information of China (English)

    Toshio Uraoka; Jun Kato; Motoaki Kuriyama; Keisuke Hori; Shin Ishikawa; Keita Harada; Koji Takemoto; Sakiko Hiraoka; Hideyuki Fujita; Joichiro Horii; Yutaka Saito; Kazuhide Yamamoto

    2009-01-01

    AIM: To clarify the effectiveness of CO_2 insufflation in potentially difficult colonoscopy cases, particularly in relation to the experience level of colonoscopists. METHODS: One hundred twenty potentially difficult cases were included in this study, which involved females with a low body mass index and patients with earlier abdominal and/or pelvic open surgery or previously diagnosed left-side colon diverticulosis. Patients receiving colonoscopy examinations without sedation using a pediatric variable-stiffness colonoscope were divided into two groups based on either CO_2 or standard air insufflation. Both insufflation procedures were also evaluated according to the experience level of the respective colonoscopists who were divided into an experienced colonoscopist (EC) group and a less experienced colonoscopist (LEC) group. Study measurements included a 100-mm visual analogue scale (VAS) for patient pain during and after colonoscopy examinations, in addition to insertion to the cecum and withdrawal times. RESULTS: Examination times did not differ, however, VAS scores in the CO_2 group were significantly better than in the air group (P < 0.001, two-way ANOVA) from immediately after the procedure and up to 2 h later. There were no significant differences between either insufflation method in the EC group (P = 0.29), however, VAS scores for CO_2 insufflation were significantly better than air insufflation in the LEC group (P = 0.023) immediately after colonoscopies and up to 4 h afterwards. CONCLUSION: CO_2 insufflation reduced patient pain after colonoscopy in potentially difficult cases when performed by LECs.

  16. Gastronet survey on the use of one- or two-person technique for colonoscopy insertion

    Directory of Open Access Journals (Sweden)

    Kjellevold Øystein

    2011-06-01

    Full Text Available Abstract Background Usually, colonoscopy insertion is performed by the colonoscopist (one-person technique. Quite common in the early days of endoscopy, the assisting nurse is now only rarely doing the insertion (two-person technique. Using the Norwegian national endoscopy quality assurance (QA programme, Gastronet, we wanted to explore the extent of two-person technique practice and look into possible differences in performance and QA output measures. Methods 100 colonoscopists in 18 colonoscopy centres having reported their colonoscopies to Gastronet between January and December 2009 were asked if they practiced one- or two-person technique during insertion of the colonoscope. They were categorized accordingly for comparative analyses of QA indicators. Results 75 endoscopists responded to the survey (representing 9368 colonoscopies - 62 of them (83% applied one-person technique and 13 (17% two-person technique. Patients age and sex distributions and indications for colonoscopy were also similar in the two groups. Caecal intubation was 96% in the two-person group compared to 92% in the one-person group (p Conclusion Two-person technique for colonoscope insertion was practiced by a considerable minority of endoscopists (17%. QA indicators were either similar to or better than one-person technique. This suggests that there may be some beneficial elements to this technique worth exploring and try to import into the much preferred one-person insertion technique.

  17. Detection and treatment of synchronous lesions in colorectal cancer: The clinical implication of perioperative colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Min Sun Kim; Young Jin Park

    2007-01-01

    AIM: To evaluate the clinical significance of pre-and intra-operative colonoscopy for the detection of synchronous lesions in colon cancer.METHODS: Two hundred and sixty-five pre-operative and 51 intra-operative colonoscopic evaluations were performed in 316 colorectal cancer patients who underwent curative resection from January 2001 to June 2006. The incidence and characteristics of synchronous lesions and their influence on surgery were evaluated.RESULTS: Two hundred and eighty-two synchronous lesions were detected in 124 (39.2%) of 316 patients including all lesions regardless of their histologic type.True adenomatous polyps were found in 91 (28.8%)of 316 patients, and 17 (5.4% of all patients) patients had synchronous colon cancers. The preoperative identification of synchronous lesions altered the planned surgery in 37 (14.0%) of 265 patients. In 18 patients among the surgically removed cases, the lesions were removed by extending the resection range.Further segmental resection or polypectomy through enterotomy was necessary in 19 patients. Nineteen (37.2%) of 51 intraoperative colonoscopy cases had synchronous lesions. Additional surgical procedures including segmental bowel resection and polypectomy with enterotomy were necessary in 7 (13.7%) of 51 intraoperative colonoscopy cases to remove the lesions.CONCLUSION: Synchronous colorectal polyps or cancer are frequent and their preoperative detection is important for optimal surgical planning and treatment.Intraoperative colonoscopy is a useful option in cases where a preoperative colonoscopy is not feasible.

  18. Willingness-to-Pay to Avoid the Time Spent and Discomfort Associated with Screening Colonoscopy

    Science.gov (United States)

    Jonas, Daniel E.; Russell, Louise B.; Chou, Jon; Pignone, Michael

    2014-01-01

    Background The screening colonoscopy process requires a considerable amount of time and some discomfort for patients. Objective We sought to use willingness-to-pay (WTP) to value the time required and the discomfort associated with screening colonoscopy. In addition, we aimed to explore some of the differences between and potential uses of the WTP and the human capital methods. Methods Subjects completed a diary recording time and a questionnaire including WTP questions to value the time and discomfort associated with colonoscopy. We also valued the elapsed time reported in the diaries (but not the discomfort) using the human capital method. Results 110 subjects completed the study. Mean WTP to avoid the time and discomfort was $263. Human capital values for elapsed time were greater. Linear regressions showed that WTP was influenced most by the difficulty of the preparation, which added $147 to WTP (p=0.03). Conclusions WTP values to avoid the time and discomfort associated with the screening colonoscopy process were substantially lower than most of the human capital values for elapsed time alone. The human capital method may overestimate the value of time in situations that involve an irregular, episodic series of time intervals, such as preparation for or recovery after colonoscopy. PMID:19725018

  19. Optimism and barriers to colonoscopy in low-income Latinos at average risk for colorectal cancer.

    Science.gov (United States)

    Efuni, Elizaveta; DuHamel, Katherine N; Winkel, Gary; Starr, Tatiana; Jandorf, Lina

    2015-09-01

    Colorectal cancer (CRC) screening continues to be underused, particularly by Latinos. CRC and colonoscopy fear, worry, and fatalism have been identified as screening barriers in Latinos. The study purpose was to examine the relationship of optimism, fatalism, worry, and fear in the context of Latinos referred for CRC screening. Our sample included 251 Latinos between the ages of 50 and 83 years who had no personal or immediate family history of CRC, no personal history of gastrointestinal disorder, no colonoscopy in the past 5 years, and received a referral for a colonoscopy. Face-to-face interviews were performed, and data were analyzed using regression models. Greater optimism (β = -1.72, p optimism (β = -0.09, p < 0.05), higher fatalism (β = 0.28, p < 0.01), and female gender (β = 0.9, p < 0.05) were associated with greater worry. Interventions that address fatalism and promote optimistic beliefs may reduce worry among Latinos referred for colonoscopy. Interventions that alleviate colonoscopy fear because of family history of cancer particularly among Latino women may help improve distress about CRC screening. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Colonoscopy sedation: clinical trial comparing propofol and fentanyl with or without midazolam.

    Science.gov (United States)

    das Neves, Jose Francisco Nunes Pereira; das Neves Araújo, Mariana Moraes Pereira; de Paiva Araújo, Fernando; Ferreira, Clarice Martins; Duarte, Fabiana Baeta Neves; Pace, Fabio Heleno; Ornellas, Laura Cotta; Baron, Todd H; Ferreira, Lincoln Eduardo Villela Vieira de Castro

    2016-01-01

    Colonoscopy is one of the most common procedures. Sedation and analgesia decrease anxiety and discomfort and minimize risks. Therefore, patients prefer to be sedated when undergoing examination, although the best combination of drugs has not been determined. The combination of opioids and benzodiazepines is used to relieve the patient's pain and discomfort. More recently, propofol has assumed a prominent position. This randomized prospective study is unique in medical literature that specifically compared the use of propofol and fentanyl with or without midazolam for colonoscopy sedation performed by anesthesiologists. The aim of this study was to evaluate the side effects of sedation, discharge conditions, quality of sedation, and propofol consumption during colonoscopy, with or without midazolam as preanesthetic. The study involved 140 patients who underwent colonoscopy at the University Hospital of the Federal University of Juiz de Fora. Patients were divided into two groups: Group I received intravenous midazolam as preanesthetic 5min before sedation, followed by fentanyl and propofol; Group II received intravenous anesthesia with fentanyl and propofol. Patients in Group II had a higher incidence of reaction (motor or verbal) to the colonoscope introduction, bradycardia, hypotension, and increased propofol consumption. Patient satisfaction was higher in Group I. According to the methodology used, the combination of midazolam, fentanyl, and propofol for colonoscopy sedation reduces propofol consumption and provides greater patient satisfaction. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  1. Comorbid Illness, Bowel Preparation, and Logistical Constraints Are Key Reasons for Outpatient Colonoscopy Nonattendance

    Directory of Open Access Journals (Sweden)

    Deepti Chopra

    2016-01-01

    Full Text Available Background. Colonoscopy nonattendance is a challenge for outpatient clinics globally. Absenteeism results in a potential delay in disease diagnosis and loss of hospital resources. This study aims to determine reasons for colonoscopy nonattendance from a Canadian perspective. Design. Demographic data, reasons for nonattendance, and patient suggestions for improving compliance were elicited from 49 out of 144 eligible study participants via telephone questionnaire. The 49 nonattenders were compared to age and sex matched controls for several potential contributing factors. Results. Nonattendance rates were significantly higher in winter months; the OR of nonattendance was 5.2 (95% CI, 1.6 to 17.0, p<0.001 in winter versus other months. Being married was positively associated with attendance. There was no significant association between nonattendance and any of the other variables examined. The top 3 reasons for nonattendance were being too unwell to attend the procedure, being unable to complete bowel preparation, or experiencing logistical challenges. Conclusions. Colonoscopy attendance rates appear to vary significantly by season and it may be beneficial to book more colonoscopies in the summer or overbook in the winter. Targets for intervention include more tailored teaching sessions, reminders, taxi chits, and developing a hospital specific colonoscopy video regarding procedure and bowel preparation requirements.

  2. Adenoma Prevalence and Distribution Among US Latino Subgroups Undergoing Screening Colonoscopy.

    Science.gov (United States)

    Chablani, Sumedha V; Jandorf, Lina; DuHamel, Katherine; Lee, Kristen K; Sriphanlop, Pathu; Villagra, Cristina; Itzkowitz, Steven H

    2017-06-01

    Colorectal cancer (CRC) is the second leading malignancy diagnosed among US Latinos. Latinos in the USA represent a heterogeneous amalgam of subgroups varying in genetic background, culture, and socioeconomic status. Little is known about the frequency of CRC precursor lesions found at screening colonoscopy among Latino subgroups. The aim was to determine the prevalence and distribution of histologically confirmed adenomas found at screening colonoscopy among average-risk, asymptomatic US Latinos according to their subgroup and socio-demographic background. Cross-sectional analysis of pathological findings resulting from screening colonoscopy among average-risk, asymptomatic US Latinos aged ≥50 in two prospective randomized controlled trials at an academic medical center. Among the 561 Latinos who completed screening colonoscopy, the two largest subgroups were Puerto Ricans and Dominicans. The findings among both subgroups were: adenomas 30.6%, proximal adenomas 23.5%, advanced adenomas 12.0%, and proximal advanced adenomas 8.9%. These rates are at least as high as those found at screening colonoscopy among US whites. While Puerto Ricans were more likely than Dominicans to be born in the USA, speak English, be acculturated, have a smoking history, and be obese, there were no significant differences in adenoma rates between these subgroups. The prevalence of adenomas, advanced adenomas, and proximal neoplasia was high among both subgroups. These findings have implications for CRC screening and surveillance among the increasingly growing Latino population in the USA.

  3. The Effect of Music on Pain, Anxiety and Vital Signs of Children during Colonoscopy

    Directory of Open Access Journals (Sweden)

    M Najafi

    2014-04-01

    Full Text Available Introduction: This study aimed to investigate the effect of music on pain, anxiety and vital signs in children undergoing colonoscopy.   Method and Materials: This randomized study was carried out on 101 children (7 to 14 years old requiring colonoscopy. Children were randomly allocated to a control or case group. The case group was played relaxing music (by Clayderman during the procedure. Spiegelberger and pain questionaires were administered immediately after the colonoscopy. Pulse rate, blood pressure and percent blood oxygen saturation were recorded for each subject. The control group was treated in an identical manner, but was not played music during the procedure. Data were analyzed using SPSS software.   Results: Satisfaction, anxiety, pain, and blood pressure were significantly different between the groups                (P0.05.   Conclusion: Music can reduce anxiety and pain during colonoscopy.   Key words: Anxiety, Music,Vital signs, Colonoscopy

  4. CT Enterography

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... kind, unlike MRI. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  5. Splenic Rupture Diagnosed with Bedside Ultrasound in a Patient with Shock in the Emergency Department Following Colonoscopy

    Directory of Open Access Journals (Sweden)

    William Mulkerin

    2015-10-01

    Full Text Available A 64-year-old male presented to the emergency department (ED with near syncope and worsening left flank and shoulder pain. He had undergone a difficult colonoscopy two days prior due to a tortuous colon. Initial vital signs were normal. He looked uncomfortable and had significant left upper quadrant abdominal tenderness with guarding. Thirty minutes after ED arrival, his blood pressure dropped to 73/59 mmHg, requiring aggressive fluid resuscitation. Bedside focused assessment with sonography in trauma (FAST exam demonstrated free fluid in the abdomen with mixed echogenicity of the spleen, suggestive of splenic injury. Computed tomography (CT demonstrated a large subcapsular splenic hematoma with active extravasation and surrounding intraperitoneal free fluid (Figure, Video. He was admitted to the surgical intensive care unit. Hemorrhage continued after interventional radiology performed embolization of the splenic artery. He then required laparoscopic splenectomy on hospital day 2 to control bleeding. He subsequently did well and was discharged on hospital day 10.

  6. Predictors of incomplete optical colonoscopy using computed tomographic colonography

    Directory of Open Access Journals (Sweden)

    Reetika Sachdeva

    2016-01-01

    Full Text Available Background/Aims: Optical colonoscopy (OC is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC. We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. Patients and Methods: In this case-control study, 70 cases ( with incomplete OC and 70 controls (with complete OC were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model. Results: On analysis, female gender (80% vs 58.6% P = 0.007, prior abdominal/pelvic surgeries (51.4% vs 14.3% P < 0.001, colonic length (187.6 ± 30.0 cm vs 163.8 ± 27.2 cm P < 0.001, and number of flexures (11.4 ± 3.1 vs 8.4 ± 2.9 P < 0.001 increased the risk for incomplete OC. No significant association was observed for increasing age (P = 0.881 and history of severe diverticulosis (P = 0.867 with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. Conclusion: Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC.

  7. A Review of Current Issues Underlying Colon Cleansing before Colonoscopy

    Directory of Open Access Journals (Sweden)

    Lawrence C Hookey

    2007-01-01

    Full Text Available The present review examines four current issues related to the efficacy, patient tolerance and safety of the following bowel cleansing agents: oral sodium phosphate (NaP, polyethylene glycol (PEG and magnesium citrate (Pico-Salax, Ferring Pharmaceuticals Inc, Canada, an agent recently made available in Canada. MedLine and PubMed databases were systematically searched to identify studies related to the efficacy of altered PEG solutions combined with adjunct treatments; the efficacy, tolerability and safety of Pico-Salax; the association between nephrocalcinosis, and chronic renal failure and oral NaP use; and the role of diet. Although lower volume PEG solutions combined with adjuvant agents were generally associated with better patient tolerance, their efficacy was varied and interpretation of this end point is complicated by study design issues. There are very few reported studies of Pico-Salax, and as a result, there are insufficient data to draw conclusions about the efficacy of this agent. The available data suggest that Pico-Salax may be better tolerated by patients, than oral NaP and PEG solutions. There is a paucity of hemodynamic monitoring data pre- and postadministration, but the available data suggests that this small-volume osmotic agent could cause subclinical contraction of the intravascular space. Recent case reports suggest an association between nephrocalcinosis and oral NaP ingestion, but to date, these reports have been confined to a single centre. Preliminary studies suggest that this is not a widespread problem, but more studies are needed. There are only a few studies examining diet and patient tolerability, but they do suggest that diet may be liberalized with some cleansing regimens to enhance tolerability without decreasing efficacy. The present review highlights current controversies and advances in colon cleansing before colonoscopy, and also identifies areas for further study.

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in ... X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography (CTA) Stroke Brain ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  10. Iatrogenic Perforations During Colonoscopy In a Portuguese Population: A Study Including In and Out-Of-Hospital Procedures

    Directory of Open Access Journals (Sweden)

    Sara Campos

    2016-07-01

    Conclusion: Perforations in colonoscopy are rare in our clinical practice. Endoscopic closure was effective, though limited to perforations found during the procedure. The mortality was relatively low and endoscopic management did not seem to worsen it. An additional effort is necessary in order to detect perforations during colonoscopy.

  11. Surveillance colonoscopy after endoscopic treatment for colorectal neoplasia: From the standpoint of the Asia-Pacific region.

    Science.gov (United States)

    Matsuda, Takahisa; Chiu, Han-Mo; Sano, Yasushi; Fujii, Takahiro; Ono, Akiko; Saito, Yutaka

    2016-04-01

    Colonoscopy is considered the gold standard to detect and remove colorectal neoplasia. The efficacy of colonoscopy with polypectomy to reduce colorectal cancer incidence and mortality has been demonstrated. Recently, post-polypectomy surveillance colonoscopy has become a necessary intervention in daily practice not only in Western countries but also in the Asia-Pacific region. Therefore, it is crucial to establish new clinical practice guidelines to reduce the number of unnecessary surveillance colonoscopies in order to create space for screening colonoscopy. The Asia-Pacific Consensus group recommended that surveillance colonoscopy interval should be tailored according to risk level of index colonoscopy. However, precise guidelines on interval of surveillance cannot be given because of a lack of prospective data. According to Korean and Australian guidelines, surveillance intervals after index colonoscopy of 5 years for low-risk subjects and 3 years for high-risk subjects are recommended in Asia-Pacific regions at present. Prospective data including long-term outcomes from the Japan Polyp Study, which is a multicenter randomized control trial, would be useful to establish the Asia-Pacific consensus in the near future.

  12. Barriers to screening colonoscopy for low-income Latino and white patients in an urban community health center.

    Science.gov (United States)

    Green, Alexander R; Peters-Lewis, Angelleen; Percac-Lima, Sanja; Betancourt, Joseph R; Richter, James M; Janairo, Maria-Pamela R; Gamba, Gloria B; Atlas, Steven J

    2008-06-01

    Colonoscopy is a screening modality for the early detection of colonic polyps and cancers but is underutilized, particularly among minorities. To identify potential barriers to screening colonoscopy among low income Latino and white non-Latino patients in an urban community health center. DESIGN, PARTICIPANTS, AND APPROACH: We conducted semistructured interviews with a convenience sample of patients 53 to 70 years old, eligible for colorectal cancer screening that spoke English or Spanish. Open-ended questions explored knowledge, beliefs, and experience with or reasons for not having screening colonoscopy. We performed content analysis of transcripts using established qualitative techniques. Of 40 participants recruited, 57% were women, 55% Latino, 20% had private health insurance, and 40% had a prior colonoscopy. Participants described a wide range of barriers categorized into 5 major themes: (1) System barriers including scheduling, financial, transportation, and language difficulties; (2) Fear of pain or complications of colonoscopy and fear of diagnosis (cancer); (3) Lack of desire or motivation, including "laziness" and "procrastination"; (4) Dissuasion by others influencing participants' decision regarding colonoscopy; and (5) Lack of provider recommendation including not hearing about colonoscopy or not understanding the preparation instructions. Understanding of the range of barriers to colorectal cancer screening can help develop multimodal interventions to increase colonoscopy rates for all patients including low-income Latinos. Interventions including systems improvements and navigator programs could address barriers by assisting patients with scheduling, insurance issues, and transportation and providing interpretation, education, emotional support, and motivational interviewing.

  13. Virtual Classroom

    DEFF Research Database (Denmark)

    Christensen, Ove

    2013-01-01

    In the Scandinavian countries: Sweden, Norway and Denmark, the project GNU (Grænseoverskridende Nordisk Undervisning, i.e. Transnational Nordic Teaching) is experimenting with ways of conducting teaching across the borders in the elementary schools. The cloud classes are organised with one class ...... and benefits in regard to learning and pedagogy with virtual classroom....

  14. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  15. Virtual Expo

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The online version of the 2010 Shanghai Expo shows the future glory The 2010 Shanghai Expo is now open and letting visitors explore almost all its pavilions and exhib-its-virtually. The website for the World Expo launched on November 12,

  16. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  17. Virtual patrolling

    NARCIS (Netherlands)

    Vlist, van der M.; Wismans, L.J.J.; Beek, van P.; Suijs, L.C.W.

    2016-01-01

    Approximately 25 per cent of all congestion on motorways is caused by incidents. By virtual patrolling, incidents e.g. queues, accidents and car breakdowns on a road network, can be predicted or detected in an early stage. This early detection and prediction of an incident likely to happen, offers t

  18. Virtual Reality.

    Science.gov (United States)

    Newby, Gregory B.

    1993-01-01

    Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

  19. Virtually There.

    Science.gov (United States)

    Lanier, Jaron

    2001-01-01

    Describes tele-immersion, a new medium for human interaction enabled by digital technologies. It combines the display and interaction techniques of virtual reality with new vision technologies that transcend the traditional limitations of a camera. Tele-immersion stations observe people as moving sculptures without favoring a single point of view.…

  20. Virtual Savannah

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    and the navigation. The test depicted how they managed to search the virtual world for answers in patterns related to restrictions in the system and using graphical points of interest as reference points. Collecting information about the complete interaction provides teachers with a tool to assess the individual...

  1. Enhanced education for bowel preparation before colonoscopy: a state-of-the-art review.

    Science.gov (United States)

    Liu, Zhu; Zhang, Ming Ming; Li, Yue Yue; Li, Li Xiang; Li, Yan Qing

    2017-01-09

    Colonoscopy remains the mainstay in the diagnosis and monitoring for colorectal cancer and other colorectal lesions. The diagnostic efficiency of colonoscopy highly depends on the quality of bowel preparation, which is closely associated with patient's compliance to preparation instructions. In addition, the procedural requirements of bowel preparation are often complex and difficult to be comprehended and memorized by patients, especially those with lower health literacy and motivation. Therefore, in recent years, many educational methods have been constantly developed, such as educational booklets, cartoon visual aids, educational videos, the short message service, the telephone, social media applications and smart phone applications. These educational methods have significantly improved the compliance with the instructions for bowel preparation and ultimately promoted the visualisation of colon in patients undergoing colonoscopy. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Colonoscopy surveillance for dysplasia and colorectal cancer in patients with inflammatory bowel disease

    DEFF Research Database (Denmark)

    Aalykke, Claus; Jensen, Michael Dam; Fallingborg, Jan;

    2015-01-01

    The risk of colorectal cancer (CRC) and dysplasia in patients with inflammatory bowel disease (IBD) has been highly debated as risk estimates from different studies vary greatly. The present national Danish guideline on colonoscopy surveillance for dysplasia and colorectal cancer in patients......, in some subgroups of patients the risk is increased. These subgroups of patients, who should be offered colonoscopy surveillance, include patients with ulcerative colitis having extensive disease and a long disease duration (10-13 years); early age at onset (less than 19 years of age) of ulcerative...... colitis; and patients with ulcerative colitis as well as Crohn´s disease with a concomitant diagnosis of primary sclerosing cholangitis. A colonoscopy surveillance program is recommended in these subgroups with intervals ranging from every 3-6 months to every 5 years, using chromoendoscopy with targeted...

  3. Trichuris trichiura infection diagnosed by colonoscopy: case reports and review of literature.

    Science.gov (United States)

    Ok, Kyung-Sun; Kim, You-Sun; Song, Jung-Hoon; Lee, Jin-Ho; Ryu, Soo-Hyung; Lee, Jung-Hwan; Moon, Jeong-Seop; Whang, Dong-Hee; Lee, Hye-Kyung

    2009-09-01

    Trichuris trichiura, commonly referred to as a whipworm, has a worldwide distribution, particularly among countries with warm, humid climates. In Korea, trichuriasis was a highly prevalent soil-transmitted helminthiasis until the 1970s. However, the nationwide prevalence decreased to 0.02% in 2004 as a result of national control activities and improvement in the socioeconomic status of Koreans. Most infected individuals have no distinct symptoms, if lightly infected. The diagnosis is typically confirmed by detection of T. trichiura eggs on examination of a stool sample; few reports have described detection of the parasite during colonoscopy. Recently, we managed 4 patients with trichuriasis who were diagnosed by detection of the parasite on colonoscopy, and we reviewed the literature on the colonoscopic diagnosis of T. trichiura in Korea. We suggest that colonoscopy might be a useful diagnostic tool, especially when infected by only a few male worms with no eggs in the stool.

  4. ORIGINAL ARTICLE: Will An Additional Observer Enhance Adenoma Detection During Colonoscopy?

    Directory of Open Access Journals (Sweden)

    Kevin D Mullen

    2012-07-01

    Full Text Available Background: Due to varied level of experience, the detection rate of adenoma on colonoscopy is different. In presence of both fellows and attending the incidence rates of adenoma are shown to increase in a small study reported by Rogart et al [4]. Based on similar hypothesis, a study was undertaken with much larger sample size to improve the power of the study. Aims and objective: To know if presence of additional observer will enhance adenoma detection during colonoscopy. Material and Methods: 2236 consecutive colonoscopies performed at Metro Health Medical Centre, Cleveland, Ohio were included in the study from July 2005 to August 2006. Cases with history of colorectal, surgical resection of colon, inflammatory bowel diseases and hereditary polyposis syndrome were excluded. Inpatient colonoscopies were also excluded. With all usual precautions for colonoscopy and after giving polyethylene glycol electrolyte (PEGEL colonoscopies were performed by one of the nine experienced staff attending using an Olympus colonoscope and Evis Exera processors. All colonoscopies performed by fellows were supervised by an attending throughout the procedure. Advanced adenomas were defined as adenomas greater than 1 cm size. Statistical analysis was done using Tall hassee, FL software; Fisher’s exact test, unpaired t test and multiple logistic regression analysis were performed. p-value of <0.05 is considered as statistically significant. Results: Of the total 2236 colonoscopies included in the study, 1527 were performed by fellows under supervision of attending and 709 by the attending. There was no significant difference in patient demographics, caecal intubation or poor preparation colonoscopies. The mean age of the group was 55 years in both of the groups. There was no statistically significant different in the polyp detection rate (35% Vs 36.8% as well as overall adenoma detection rate (28.4% Vs 27.7% between these two groups of performers. However

  5. CT colonography for surveillance of patients with colorectal cancer: Systematic review and meta-analysis of diagnostic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Porte, Francois; Burling, David [St. Mark' s Hospital, Department of Radiology, Harrow (United Kingdom); Uppara, Mallikarjuna; Malietzis, George; Faiz, Omar [Trials and Outcome Centre (SETOC) St Mark' s Hospital, Surgical Epidemiology, Harrow (United Kingdom); Halligan, Steve [University College London, Department of Radiology, London (United Kingdom); Athanasiou, Thanos [Imperial College London, Department of Surgery and Cancer, London (United Kingdom)

    2017-01-15

    To review primary research evidence investigating performance of CT colonography for colorectal cancer surveillance. The financial impact of using CT colonography for surveillance was also estimated. We identified primary studies of CT colonography for surveillance of colorectal cancer patients. A summary ROC curve was constructed. Inter-study heterogeneity was explored using the I2 value. Financial impact was estimated for a theoretical cohort of patients, based on Cancer Research UK statistics. Seven studies provided data on 880 patients. Five of seven studies (765 patients) were included for qualitative analysis. Sensitivity of CT colonography for detection of anastomotic recurrence was 95 % (95 % CI 62 - 100), specificity 100 % (95 % CI 75 - 100) and sensitivity for metachronous cancers was 100 %. No statistical heterogeneity was detected (I2 = 0 %). We estimated that CT colonography as a 'single test' alternative to colonoscopy and standard CT for surveillance would potentially save EUR20,785,232 (pound 14,803,404) for an annual cohort of UK patients. CT colonography compares favourably to colonoscopy for detection of anastomotic recurrence and metachronous colorectal cancer, and appears financially beneficial. These findings should be considered alongside limitations of small patient numbers and high clinical heterogeneity between studies. (orig.)

  6. CT colonography practice in the UK: a national survey

    Energy Technology Data Exchange (ETDEWEB)

    Burling, D.; Halligan, S. E-mail: s.halligan@imperial.ac.uk; Taylor, S.A.; Usiskin, S.; Bartram, C.I

    2004-01-01

    AIM: To determine the provision of computed tomography (CT) colonography in UK radiology departments. MATERIALS AND METHODS: A questionnaire relating to the availability of CT colonography, barriers to implementation, clinical indications, technique, and practitioners was posted to clinical directors of UK radiology departments. RESULTS: One hundred and thirty-eight departments responded. Fifty (36%) offered CT colonography in day-to-day clinical practice. Of those that did not, 68 of 87 (64%) cited limited scanner capacity as the main barrier. Of the 50 departments offering a service, 39 (78%) offered CT after incomplete colonoscopy, 36 (72%), after failed barium enema, and 37 (74%) as an alternative to barium enema. Of those offering a service, the number of studies performed varied between one per month (38%) to more than one per day (8%). Total experience varied between 20 or fewer studies (28%) to more than 300 (12%). Full bowel preparation was common (92%), as was dual positioning (90%). Colonography was interpreted by radiologists with a subspecialty interest in gastrointestinal imaging in 64% of centres offering a service. CONCLUSION: CT colonography is widely available in the UK, with approximately one-third of responders offering a service. Experience and throughput varies considerably. Limited CT scanner capacity is the major barrier to further dissemination.

  7. Enhanced flat adenoma detection rate with high definition colonoscopy plus i-scan for average-risk colorectal cancer screening

    Directory of Open Access Journals (Sweden)

    Antonio Rodríguez-D'Jesús

    Full Text Available Background and aim: The usefulness of high definition colonoscopy plus i-scan (HD+i-SCAN for average-risk colorectal cancer screening has not been fully assessed. The detection rate of adenomas and other measurements such as the number of adenomas per colonoscopy and the flat adenoma detection rate have been recognized as markers of colonoscopy quality. The aim of the present study was to compare the diagnostic performance of an HD+i-SCAN with that of standard resolution white-light colonoscope. Methods: This is a retrospective analysis of a prospectively collected screening colonoscopy database. A comparative analysis of the diagnostic yield of an HD+i-SCAN or standard resolution colonoscopy for average-risk colorectal screening was conducted. Results: During the period of study, 155/163 (95.1% patients met the inclusion criteria. The mean age was 56.9 years. Sixty of 155 (39% colonoscopies were performed using a HD+i-SCAN. Adenoma-detection-rates during the withdrawal of the standard resolution versus HD+i-SCAN colonoscopies were 29.5% and 30% (p = n.s.. Adenoma/colonoscopy values for standard resolution versus HD+i-SCAN colonoscopies were 0.46 (SD = 0.9 and 0.72 (SD = 1.3 (p = n.s.. A greater number of flat adenomas were detected in the HD+i-SCAN group (6/60 vs. 2/95 (p < .05. Likewise, serrated adenomas/polyps per colonoscopy were also higher in the HD+i-SCAN group. Conclusions: A HD+i-SCAN colonoscopy increases the flat adenoma detection rate and serrated adenomas/polyps per colonoscopy compared to a standard colonoscopy in average-risk screening population. HD+i-SCAN is a simple, available procedure that can be helpful, even for experienced providers. The performance of HD+i-SCAN and substantial prevalence of flat lesions in our average-risk screening cohort support its usefulness in improving the efficacy of screening colonoscopies.

  8. 3D virtual table in anatomy education

    DEFF Research Database (Denmark)

    Dahl, Mads Ronald; Simonsen, Eivind Ortind

    The ‘Anatomage’ is a 3D virtual human anatomy table, with touchscreen functionality, where it is possible to upload CT-scans and digital. Learning the human anatomy terminology requires time, a very good memory, anatomy atlas, books and lectures. Learning the 3 dimensional structure, connections...

  9. Low rate of postpolypectomy bleeding among patients who continue thienopyridine therapy during colonoscopy.

    Science.gov (United States)

    Feagins, Linda A; Iqbal, Ramiz; Harford, William V; Halai, Akeel; Cryer, Byron L; Dunbar, Kerry B; Davila, Raquel E; Spechler, Stuart J

    2013-10-01

    It is not clear whether the cardiovascular risk of discontinuing treatment with antiplatelet agents, specifically the thienopyridines, before elective colonoscopy outweighs the risks of postpolypectomy bleeding (PPB). We studied the rate of PPB in patients who continue thienopyridine therapy during colonoscopy. We performed a prospective study of 516 patients not taking warfarin who received polypectomies during elective colonoscopies; 219 were receiving thienopyridines, and 297 were not (controls). The occurrence of immediate PPB and delayed PPB was recorded. Delayed PPB was categorized as clinically important if it resulted in repeat colonoscopy, hospitalization, or blood transfusion. Patients receiving thienopyridines were older and had significantly more comorbid diseases than controls; the mean number of polyps removed per patient was significantly higher (3.9 vs 2.9) in the thienopyridine group. Immediate PPB developed in 16 patients in the thienopyridine group (7.3%) and in 14 in the control group (4.7%, P = .25). Among patients who completed a 30-day follow-up analysis (96% of patients enrolled), clinically important, delayed bleeding occurred in 2.4% of patients receiving thienopyridines and in none of the controls (P = .01). All PPB events in both groups were resolved without surgery, angiography, or death. Although a significantly higher percentage of patients who continue thienopyridine therapy during colonoscopy and polypectomy develop clinically important delayed PPB than patients who discontinue therapy, the rate of PPB events is low (2.4%), and all are resolved without sequelae. The risk for catastrophic cardiovascular risks among patients who discontinue thienopyridine therapy before elective colonoscopies could therefore exceed the risks of PPB. ClinicalTrials.gov, Number NCT01647568. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  10. Evaluating screening colonoscopy quality in an uninsured urban population following patient navigation

    Directory of Open Access Journals (Sweden)

    Keith Naylor

    2017-03-01

    Full Text Available Patient navigation (PN increases screening colonoscopy completion in minority and uninsured populations. However, colonoscopy quality is under-reported in the setting of PN and quality indicators have often failed to meet benchmark standards. This study investigated screening colonoscopy quality indicators after year-one of a PN initiative targeting the medically uninsured. This was a retrospective analysis of 296 outpatient screening colonoscopies. Patients were 45 to 75 years of age with no history of bowel cancer, inflammatory bowel disease, or colorectal surgery. The screening colonoscopy quality indicators: adenoma detection rate (ADR, cecal intubation rate (CIR, and bowel preparation quality were compared in 89 uninsured Federally Qualified Health Center (FQHC patients who received PN and 207 University Hospital patients who received usual care. The FQHC PN and University Hospital cohorts were similar in female sex (69% vs. 70%; p = 0.861 and African American race (61% vs. 61%; p = 0.920. The FQHC PN cohort was younger (57 years vs. 60 years; p < 0.001. There was no difference in ADR (33% vs. 32%; p = 0.971 or CIR (96% vs. 95%; p = 0.900 comparing the FQHC PN and University Hospital cohorts. The FQHC PN patients had a greater likelihood of an optimal bowel preparation on multivariate logistic regression (odds ratio 4.17; 95% confidence interval 1.07 to 16.20. Uninsured FQHC patients who received PN were observed to have intra-procedure quality indicators that exceeded bench-mark standards for high-quality screening colonoscopy and were equivalent to those observed in an insured University Hospital patient population.

  11. Safety and effectiveness of propofol sedation during and after outpatient colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Akira Horiuchi; Yoshiko Nakayama; Masashi Kajiyama; Naoyuki Kato; Tetsuya Kamijima; Yasuyuki Ichise; Naoki Tanaka

    2012-01-01

    AIM:To study the safety and effectiveness of propofol sedation for outpatient colonoscopy.METHODS:Propofol was given by bolus injection with an age-adjusted standard protocol consisting of 60 mg for patients < 70 years old,40 mg for patients age 70-89 years,and 20 mg for those ≥ 90 years,and additional injections of 20 mg propofol were given up to a maximum of 200 mg.The principal parameters were the occurrence of adverse events within 24 h after colonoscopy and overall satisfaction for this procedure.Secondary parameters included successful procedure,respiratory depression,and other complications.RESULTS:Consecutive patients were entered prospectively and all 2101 entered successfully completed outpatient colonoscopy.The mean dose of propofol used was 96.4 mg (range 40-200 mg).Younger patients required higher doses of propofol than older patients (20-40 years vs ≥ 61 years:115.3±32 mg vs 89.7 ± 21 mg,P < 0.001).Transient supplemental oxygen supply was needed by five patients (0.2%);no other complications occurred.The questionnaires were completed by 1820 (87%) of 2101 patients and most rated their overall satisfaction as excellent (80%)or good (17%).The majority (65%) of patients drove home or to their office after their colonoscopy.Most (99%) were willing,to repeat the same procedure.No incidents occurred within 24 h after colonoscopy.CONCLUSION:Propofol sedation using a dose < 200 mg proved both safe and practical for outpatient colonoscopy.

  12. CT in vascular pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, C.; Neri, E.; Caramella, D. [Diagnostic and Interventional Radiology Department of Oncology, University of Pisa, Via Roma 67, I-56100 Pisa (Italy)

    1998-06-02

    Since the introduction of helical scanners, CT angiography (CTA) has achieved an essential role in many vascular applications that were previously managed with conventional angiography. The performance of CTA is based on the accurate selection of collimation width, pitch, reconstruction spacing and scan delay, which must be modulated on the basis of the clinical issue. However, the major improvement of CT has been provided by the recent implementation of many post-processing techniques, such as multiplanar reformatting, shaded surface display, maximum intensity projections, 3D perspectives of surface and volume rendering, which simulate virtual intravascular endoscopy. The integration of the potentialities of the scanner and of the image processing techniques permitted improvement of: (a) the evaluation of aneurysms, dissection and vascular anomalies involving the thoracic aorta; (b) carotid artery stenosis; (c) aneurysms of abdominal aorta; (d) renal artery stenosis; (e) follow-up of renal artery stenting; and (f) acute or chronic pulmonary embolism. Our experience has shown that the assessment of arterial pathologies with CTA requires the integration of 3D post-processing techniques in most applications. (orig.) With 4 figs., 34 refs.

  13. Follow-up of Pseudomembranous Colitis in Children Using Colonoscopy: A Case Report.

    Science.gov (United States)

    Zhao, Q; Yuan, H; Hu, H; Yan, M Q

    2015-09-01

    Pseudomembranous colitis (PMC) occurs mainly in adults and is believed to be caused almost exclusively by toxins produced by Clostridium difficile. Colonoscopy found that PMC occurs mainly in the colon, sigmoid colon and rectum in up to 80% ~ 100% of cases. Colonoscopy is simple and fast. It has the significance of making a definite diagnosis and can be used as the main examination method of diagnosis. Reports of children suffering from PMC are rare. Herein, we report a case of PMC in a child. This report has some clinical value for the study of the spectrum of PMC in patients.

  14. Patient acceptance of MR colonography with improved fecal tagging versus conventional colonoscopy

    DEFF Research Database (Denmark)

    Achiam, M P; Løgager, V; Chabanova, E;

    2010-01-01

    Conventional colonoscopy (CC) is the gold standard for colonic examinations. However, patient acceptance is not high. Patient acceptance is influenced by several factors, notably anticipation and experience. This has led to the assumption that patient acceptance would be higher in non-invasive ex......Conventional colonoscopy (CC) is the gold standard for colonic examinations. However, patient acceptance is not high. Patient acceptance is influenced by several factors, notably anticipation and experience. This has led to the assumption that patient acceptance would be higher in non...

  15. Change in renal function after sodium phosphate preparation for screening colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Dong; Choon; Seol; Sung; Noh; Hong; Jeong; Hwan; Kim; In; Kyung; Sung; Hyung; Seok; Park; Jung; Hyun; Lee; Chan; Sup; Shim

    2010-01-01

    AIM:To investigate the changes in renal function at 12-24 mo in patients following sodium phosphate(NaP) preparation for screening colonoscopy.METHODS:We carried out a retrospective study on the results from patients who received health check-up services as part of an employer-provided wellness program performed between August 2006 and May 2008 and who were followed up for 12-24 mo.Prior to screening colonoscopy,224 patients underwent bowel cleansing with NaP(NaP group) and 113 patients with polyethylene gl...

  16. Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening

    Science.gov (United States)

    Liedenbaum, M H; van Rijn, A F; de Vries, A H; Dekker, H M; Thomeer, M; van Marrewijk, C J; Hol, L; Dijkgraaf, M G W; Fockens, P; Bossuyt, P M M; Dekker, E; Stoker, J

    2009-01-01

    Objective: The purpose of this study was to evaluate the effectiveness of CT colonography (CTC) as a triage technique in faecal occult blood test (FOBT)-positive screening participants. Methods: Consecutive guaiac (G-FOBT) and immunochemical (I-FOBT) FOBT-positive patients scheduled for colonoscopy underwent CTC with iodine tagging bowel preparation. Each CTC was read independently by two experienced observers. Per patient sensitivity, specificity and positive and negative predictive values (PPV and NPV) were calculated based on double reading with different CTC cut-off lesion sizes using segmental unblinded colonoscopy as the reference standard. The acceptability of the technique to patients was evaluated with questionnaires. Results: 302 FOBT-positive patients were included (54 G-FOBT and 248 I-FOBT). 22 FOBT-positive patients (7%) had a colorectal carcinoma and 211 (70%) had a lesion ⩾6 mm. Participants considered colonoscopy more burdensome than CTC (p<0.05). Using a 6 mm CTC size cut-off, per patient sensitivity for CTC was 91% (95% CI 85% to 91%) and specificity was 69% (95% CI 60% to 89%) for the detection of colonoscopy lesions ⩾6 mm. The PPV of CTC was 87% (95% CI 80% to 93%) and NPV 77% (95% CI 69% to 85%). Using CTC as a triage technique in 100 FOBT-positive patients would mean that colonoscopy could be prevented in 28 patients while missing ⩾10 mm lesions in 2 patients. Conclusion: CTC with limited bowel preparation has reasonable predictive values in an FOBT-positive population and a higher acceptability to patients than colonoscopy. However, due to the high prevalence of clinically relevant lesions in FOBT-positive patients, CTC is unlikely to be an efficient triage technique in a first round FOBT population screening programme. PMID:19625276

  17. Chronic methadone use, poor bowel visualization and failed colonoscopy: A preliminary study

    Institute of Scientific and Technical Information of China (English)

    Siddharth Verma; Joshua Fogel; David J Beyda; Brett Bernstein; Vincent Notar-Francesco; Smruti R Mohanty

    2012-01-01

    AIM:To examine effects of chronic methadone usage on bowel visualization,preparation,and repeat colonoscopy.METHODS:In-patient colonoscopy reports from October,2004 to May,2009 for methadone dependent (MD) patients were retrospectively evaluated and compared to matched opioid naive controls (C).Strict criteria were applied to exclude patients with risk factors known to cause constipation or gastric dysmotility.Colonoscopy reports of all eligible patients were analyzed for degree of bowel visualization,assessment of bowel preparation (good,fair,or poor),and whether a repeat colonoscopy was required.Bowel visualization was scored on a 4 point scale based on multiple prior studies:excellent =1,good =2,fair =3,or poor =4.Analysis of variance (ANOVA) and Pearson x2 test were used for data analyses.Subgroup analysis included correlation between methadone dose and colonoscopy outcomes.All variables significantly differing between MD and C groups were included in both univariate and multivariate logistic regression analyses.P values were two sided,and <0.05 were considered statistically significant.RESULTS:After applying exclusionary criteria,a total of 178 MD patients and 115 C patients underwent a colonoscopy during the designated study period.A total of 67 colonoscopy reports for MD patients and 72 for C were included for data analysis.Age and gender matched controls were randomly selected from this population to serve as controls in a numerically comparable group.The average age for MD patients was 52.2 ± 9.2 years (range:32-72 years) years compared to 54.6 ± 15.5 years (range:20-81 years) for C (P =0.27).Sixty nine percent of patients in MD and 65% in C group were males (P =0.67).When evaluating colonoscopy reports for bowel visualization,MD patients had significantly greater percentage of solid stool (i.e.,poor visualization) compared to C (40.3% vs 6.9%,P < 0.001).Poor bowel preparation (35.8% vs 9.7%,P < 0.001) and need for repeat colonoscopy (32

  18. Importance of Heparin Provocation and SPECT/CT in Detecting Obscure Gastrointestinal Bleeding on 99mTc-RBC Scintigraphy

    OpenAIRE

    2015-01-01

    Abstract We presented a pediatric case with a history of intermittent melena for 3 years because of angiodyplasia of small intestine. The results of frequent upper gastrointestinal endoscopies and colonoscopies as well as both 99mTc-red blood cell (RBC) and Meckel's scintigraphies for several times were negative in detection of bleeding site. However, 99mTc-RBC scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT) after heparin augmentation detected a s...

  19. Virtual reality

    Energy Technology Data Exchange (ETDEWEB)

    Pokras, V. [Liebherr Mining Equipment Co. (US)

    2005-03-01

    The paper weighs up the pros and cons between virtual prototyping and physical prototyping. Liebherr Mining Equipment Co. (LME) started evaluating the multi-body dynamic simulation of a full truck six years ago. LME has developed a series of dynamic models to optimise design of its T282B diesel-electric truck. Also, LME has developed a GPS-based technique called Virtual Mine Site that allows easy obtaining of a haul cycle 3D road profile for a specific mine site. The system can obtain not only a travel path and elevation profile but also body pitch, roll and acceleration components, allowing design optimisation and validation for structural and mechanical components. 2 figs., 2 photos.

  20. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

    Garbaya, S.; Miraoui, C.; Wendrich, R.E.; Lim, T.; Stanescu, I.A.; Hauge, J.B.

    2014-01-01

    Virtual reality and virtualization are currently used to design complex systems and demonstrate that they represent the functionalities of real systems. However, the design refinement of the virtual environment (VE) and distributed virtual environment (DVE) are still time consuming and costly, as it

  1. Virtual teams

    OpenAIRE

    Sanders, David

    2010-01-01

    This paper describes some early results from observing and interviewing groups working to achieve intellectually complex tasks that required the use of computers, WWW and other research resources. Three groups were virtual (they were working at a distance and rarely meeting face to face) and two groups were simple control groups They were real groups (working in relatively close proximity so that face to face contact was possible most of the time). All five teams completed their tasks but a s...

  2. Virtual anthropology.

    Science.gov (United States)

    Weber, Gerhard W

    2015-02-01

    Comparative morphology, dealing with the diversity of form and shape, and functional morphology, the study of the relationship between the structure and the function of an organism's parts, are both important subdisciplines in biological research. Virtual anthropology (VA) contributes to comparative morphology by taking advantage of technological innovations, and it also offers new opportunities for functional analyses. It exploits digital technologies and pools experts from different domains such as anthropology, primatology, medicine, paleontology, mathematics, statistics, computer science, and engineering. VA as a technical term was coined in the late 1990s from the perspective of anthropologists with the intent of being mostly applied to biological questions concerning recent and fossil hominoids. More generally, however, there are advanced methods to study shape and size or to manipulate data digitally suitable for application to all kinds of primates, mammals, other vertebrates, and invertebrates or to issues regarding plants, tools, or other objects. In this sense, we could also call the field "virtual morphology." The approach yields permanently available virtual copies of specimens and data that comprehensively quantify geometry, including previously neglected anatomical regions. It applies advanced statistical methods, supports the reconstruction of specimens based on reproducible manipulations, and promotes the acquisition of larger samples by data sharing via electronic archives. Finally, it can help identify new, hidden traits, which is particularly important in paleoanthropology, where the scarcity of material demands extracting information from fragmentary remains. This contribution presents a current view of the six main work steps of VA: digitize, expose, compare, reconstruct, materialize, and share. The VA machinery has also been successfully used in biomechanical studies which simulate the stress and strains appearing in structures. Although

  3. 对腺样体肥大儿童进行CT多平面重建与仿真内镜检查的诊断价值%The Diagnostic Value of CT Multiplanar Reconstruction and Virtual Endoscopy in Pediatric Adenoidal Hypertrophy

    Institute of Scientific and Technical Information of China (English)

    刘伟; 陈刚; 王卉

    2016-01-01

    目的:探讨螺旋CT多平面重建与仿真内镜技术在儿童腺样体肥大中的诊断价值。方法:将60例4-13岁腺样体肥大的儿童随机分为实验组和对照组(每组30例)。实验组行鼻咽部CT扫描及鼻内镜检查,并使用CT扫描机同机工作站进行仿真内镜检查,构建重组图像。对照组行鼻咽侧位X线平片扫描及鼻内镜检查。两组均通过蝶-枕骨结合部层面,测量正中矢状位腺样体最大厚度与鼻咽腔前后径比值(A/N)、与鼻内镜直视下腺样体肥大的分度进行比较。结果:螺旋CT多平面重建图像能清晰、全面地显示腺样体肥大的程度及其与周围结构的关系。实验组患者中腺样体轻度肥大6例,中度肥大15例,重度肥大9例,与鼻内镜检查结果相符;仿真内镜下可见肥大的腺样体占据后鼻孔:I度阻塞2例,II度阻塞6例,III度阻塞106例,IV度阻塞12例,与鼻内镜检查结果一致(P=0.431)。对照组患者中腺样体轻度肥大5例,中度肥大8例,重度肥大17例,与鼻内镜检查差异有统计学意义(P=0.009)。结论:螺旋CT多平面及仿真内镜检查可更准确、全面、客观地提供腺样体的测量数据,在儿童腺样体肥大的诊断上较鼻咽侧位X线平片具有更高的临床应用价值。%Objective: To explore the diagnostic value of CT multiplanar reconstruction and virtual endoscopy in Pediatric Adenoidal Hypertrophy. Method: A total of 60 children aged 4-13 years were diagnosed with Pediatric Adenoidal Hypertrophy. 30 cases were examined by nasal endoscope and scanned by nasopharyngeal CT with image construction of virtual endoscopy, 30 cases were examined by nasal endoscope and nasopharyngeal lateral X-ray. Two groups measured the maximum thickness of adenoid diameter of nasopharyngeal air space ratio(A/N), then compared with the indexing of adenoid hypertrophy under nasal endoscop. Results: CT multiplanar

  4. Dual energy CT: New horizon in medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2017-08-01

    Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

  5. Dual-Energy CT: New Horizon in Medical Imaging.

    Science.gov (United States)

    Goo, Hyun Woo; Goo, Jin Mo

    2017-01-01

    Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

  6. Closed loop control of sedation for colonoscopy using the Bispectral Index

    NARCIS (Netherlands)

    Leslie, K.; Absalom, A.; Kenny, G. N. C.

    Sixteen patients undergoing colonoscopy were sedated with propofol using a closed-loop control system guided by the Bispectral Index (BIS). Propofol administration, via a target-controlled infusion, was controlled by a proportional-integral-differential control algorithm. The median (range) propofol

  7. Use, appropriateness, and diagnostic yield of screening colonoscopy: an international observational study (EPAGE)

    DEFF Research Database (Denmark)

    Burnand, B; JK, Harris; Wietlisbach, V

    2006-01-01

    was asked of all centers, it is possible that not all consecutive patients were included. Participating centers were a convenience sample and thus may not be representative. CONCLUSIONS: About 1 of 10 colonoscopies were performed for screening, preferentially in middle-aged individuals. A higher diagnostic...

  8. Seeing better--Evidence based recommendations on optimizing colonoscopy adenoma detection rate.

    Science.gov (United States)

    Aranda-Hernández, Javier; Hwang, Jason; Kandel, Gabor

    2016-02-07

    Colorectal cancer is one of the three most frequent causes of cancer deaths in men and women in Europe and North America. Diagnosis and resection of adenomas has convincingly demonstrated its utility in diminishing colorectal cancer incidence. Therefore, colonoscopy is now the gold standard for colorectal cancer screening. But it is also known that colonoscopy effectiveness varies among endoscopists. Among different quality indicators, the most used is the adenoma detection rate (ADR) which is the percentage of average-risk patients for colorectal cancer who are found to have at least one adenoma or adenocarcinoma during a screening colonoscopy. There is compelling evidence supporting an inverse correlation between ADR and interval colorectal cancer (cancer found after a screening colonoscopy). Many factors such as quality of precolonoscopy preparation, additional observers, manoeuvres with the endoscope (second view, retroflexion, water inflation rather than air), time spent during withdrawal, changes in patient position, fold-flattener devices, new imaging or endoscopic modalities and use of intravenous or through the scope sprayed drugs, have been studied and developed with the aim of increasing the ADR. This reviews discusses these factors, and the current evidence, to "see better" in the colon and optimize ADR.

  9. Development of a colonoscopy add-on device for improvement of the intubation process

    Directory of Open Access Journals (Sweden)

    Litten JD

    2011-12-01

    Full Text Available Jonathan D Litten1, JungHun Choi2, David Drozek31Department of Mechanical Engineering; 2Department of Mechanical Engineering and Biomedical Engineering Program; 3College of Osteopathic Medicine, Department of Specialty Medicine, Ohio University, Athens, OH, USAAbstract: A colonoscopy add-on device has been developed to reduce intubation time without modification of the current colonoscope and peripheral devices. One of the main purposes of the system is to minimize trauma caused by the distal tip of the colonoscope. The detachable sensory fixture at the end of the distal tip measures the distance between the distal tip and the colon wall in three directions, and the actuation system attached at the base of the colonoscope controls the distal tip by rotating two dial knobs. The device controls the distal tip to minimize contact between the distal tip and the colon wall, and the distal tip ideally points out the next possible lumen. A compatibility test of the infrared sensory system was carried out, and the design of the actuation system was accomplished. The system is integrated and controlled by a microprocessor. The device was tested in a silicon colon and porcine intestine. The results showed that a colonoscopist successfully reached the cecum with the aid of the colonoscopy add-on device without significant contact between the colon wall and the distal tip. The colonoscopy aid device was very helpful for the novice colonoscopist.Keywords: colonoscope, infrared sensors, intubation, trauma, colonoscopy training model

  10. Colon Capsule Endoscopy: Detection of Colonic Polyps Compared with Conventional Colonoscopy and Visualization of Extracolonic Pathologies

    Directory of Open Access Journals (Sweden)

    Alexander F Hagel

    2014-01-01

    Full Text Available BACKGROUND: Conventional colonoscopy (CC is the gold standard for diagnostic examination of the colon. However, the overall acceptance of this procedure is low due to patient fears of complications or embarrassment. Colon capsule endoscopy (CCE represents a minimally invasive, patient-friendly procedure that offers complete visualization of the entire intestine.

  11. Appropriateness of colonoscopy in Europe (EPAGE II). Screening for colorectal cancer

    DEFF Research Database (Denmark)

    Arditi, C; Peytremann-Bridevaux, I; Burnand, B;

    2009-01-01

    BACKGROUND AND STUDY AIMS: To summarize the published literature on assessment of appropriateness of colonoscopy for screening for colorectal cancer (CRC) in asymptomatic individuals without personal history of CRC or polyps, and report appropriateness criteria developed by an expert panel, the 2...

  12. The effect of auricular acupuncture on pain during colonoscopy with midazolam and pethidine

    Science.gov (United States)

    Kusumastuti, R.; Srilestari, A.; Abdurrohim, K.; Abdullah, M.

    2017-08-01

    Colonoscopy is the standard procedure for colorectal cancer screening. One of its common complications is abdominal pain. Analgesia has not provided favorable outcomes so various complementary practices have been developed, including auricular acupuncture. In this study, a randomized controlled trial of 56 patients who underwent colonoscopy was conducted to determine the effect of acupuncture on the pain experienced during colonoscopy. Subjects were divided into two groups: The first received acupuncture combined with midazolam and pethidine, while the second were administered placebo puncture in addition to midazolam and pethidine. The median Critical Care Pain Observation Tool (CPOT) score was lower in the auricular acupuncture group than in the placebo puncture group(0.7 [0-4.83] vs. 1.9 [0-6.20] p = 0.010), while there were no significant differences to median Visual Analog Scale (VAS) scores (29 [0-100] vs. 44.5 [0-100] p = 0.147), heart rate changes (-2.58 [14.31] vs.-2.43 [12.28]; p = 0.970), or the mean time to the cecum (16 [8-51] vs. 22 [5-63] p = 0.206). Auricular acupuncture combined with midazolam and pethidine was found to be effective at reducing pain during colonoscopy.

  13. Colonoscopy results are not enhanced by use of magnet endoguide in specialist practice

    DEFF Research Database (Denmark)

    Bak-Christensen, Anders; Knudsen, Elisabeth; Hendel, Jakob;

    2013-01-01

    screening. UPD has been proposed as a tool for optimization of results and reduction of patient discomfort. In this study, we aimed to qualify the debate by examining the success rate and patient discomfort in an unselected colonoscopy population referred to specialist clinics with experienced investigators...

  14. Colonoscopy surveillance for dysplasia and colorectal cancer in patients with inflammatory bowel disease

    DEFF Research Database (Denmark)

    Aalykke, Claus; Jensen, Michael Dam; Fallingborg, Jan

    2015-01-01

    colitis; and patients with ulcerative colitis as well as Crohn´s disease with a concomitant diagnosis of primary sclerosing cholangitis. A colonoscopy surveillance program is recommended in these subgroups with intervals ranging from every 3-6 months to every 5 years, using chromoendoscopy with targeted...

  15. PET-CT enteroclysis: a new technique for evaluation of inflammatory diseases of the intestine

    Energy Technology Data Exchange (ETDEWEB)

    Jyoti Das, Chandan; Sharma, Raju [All India Institute of Medical Sciences, Department of Radiodiagnosis, New Delhi (India); Makharia, Govind; Goswami, Pooja [All India Institute of Medical Sciences, Department of Gastroenterology and Human Nutrition, New Delhi (India); Kumar, Rakesh; Chawla, Madhavi; Malhotra, Arun [All India Institute of Medical Sciences, Ansari Nagar, Department of Nuclear Medicine, New Delhi (India)

    2007-12-15

    While CT/MR enteroclysis provides excellent anatomical details, it fails to provide information on metabolic activity of the inflammatory lesions of the intestine. We conceptualized a fusion of metabolic imaging techniques such as PET and an anatomical imaging modality such as CT enteroclysis to derive information both on morphological details and functional activity of lesions at the same time. In a prospective study, we included 17 adult patients with newly diagnosed inflammatory diseases of the intestine. Low dose whole body PET-CT scan was obtained first, which began at approximately 60 min after injection of 10 mCi of {sup 18}fluoro-deoxyglucose (FDG). Subsequently, PET-CT enteroclysis of the abdomen was performed after infusion of 2 l of 0.5% methylcellulose through a naso-jejunal catheter. Fourteen patients had abnormal and three had normal PET-CT enteroclysis studies. Twenty-three segments of small intestine and 27 segments of large intestine showed increased FDG uptake. The detection rate of PET-CT enteroclysis was significantly higher (total =50 segments, 23 segments of small intestine and 27 segments of large intestine) as compared with barium studies (16 segments of small intestine) and colonoscopy (17 segments of large intestine) combined together (total =33 segments). In addition PET-CT enteroclysis showed extra-luminal FDG uptake (lymph nodes in two, sacroilitis in two, and mesenteric fat proliferation in five). As a single investigation, PET-CT enteroclysis detects a significantly higher number of lesions both in the small and large intestine in comparison to that detected by conventional barium and colonoscopy combined together. This technique is non-invasive, feasible and very promising. (orig.)

  16. Reluctance to screening colonoscopy in Arab Americans: a community based observational study.

    Science.gov (United States)

    Talaat, Nizar; Harb, Walid

    2013-08-01

    To explore compliance of Arab-Americans to colorectal cancer (CRC) screening and identify the barriers for non-compliance. An observational community based study. Arab-American Friday prayer attendees' ≥50 years in three mosques in Dearborn, MI volunteered. Demographics, health insurance status, screening history, availability of a primary care physician (PCP) and the ability to communicate in Arabic were inquired. The responses were compared using a student t test between respondents who have had CRC screening with colonoscopy and those who have not had any screening tests. A p value of 0.05 or lower was considered statistically significant. Total number surveyed was 130. Average age is 64 years. Males were 76 % (99) and females 24 % (31). More than 50 % were Lebanese and 28 % were from Yemen. Majority had health insurance (89 %), and 86 % had a primary care physician of which 79 % of them spoke Arabic. Half of the participants had colonoscopy mostly for screening purposes. Fifty-eight (45 %) participants did not have CRC screening. Majority of the females (72.4 %) had colonoscopy compared to 46.8 % of the males (p value = 0.016). The mean length of stay in the U.S was 39.16 years in the colonoscopy group compared to 30.77 years in the non-screening group (p value = 0.006). Participants without a PCP did not have CRC screening (77.8 %) (p value = 0.005). Participants with a non-Arabic speaking PCP had more colonoscopy rates (77.3 %) compared to those with an Arabic speaking PCP (50 %) (p value = 0.027). More Lebanese had colonoscopy (71.9 %) compared to 25.7 % of the surveyed Yemenis (p value = 0.00). Discomfort, unawareness about CRC screening, and nonrecommendation by PCP were reported barriers. Arab-Americans have lower screening colonoscopy rates. Unfamiliarity of the importance of screening is a principal issue. Having a non-arabic speaking PCP is beneficial. Better education to this population about the benefits and ease of

  17. High-performance computer aided detection system for polyp detection in CT colonography with fluid and fecal tagging

    Science.gov (United States)

    Liu, Jiamin; Wang, Shijun; Kabadi, Suraj; Summers, Ronald M.

    2009-02-01

    CT colonography (CTC) is a feasible and minimally invasive method for the detection of colorectal polyps and cancer screening. Computer-aided detection (CAD) of polyps has improved consistency and sensitivity of virtual colonoscopy interpretation and reduced interpretation burden. A CAD system typically consists of four stages: (1) image preprocessing including colon segmentation; (2) initial detection generation; (3) feature selection; and (4) detection classification. In our experience, three existing problems limit the performance of our current CAD system. First, highdensity orally administered contrast agents in fecal-tagging CTC have scatter effects on neighboring tissues. The scattering manifests itself as an artificial elevation in the observed CT attenuation values of the neighboring tissues. This pseudo-enhancement phenomenon presents a problem for the application of computer-aided polyp detection, especially when polyps are submerged in the contrast agents. Second, general kernel approach for surface curvature computation in the second stage of our CAD system could yield erroneous results for thin structures such as small (6-9 mm) polyps and for touching structures such as polyps that lie on haustral folds. Those erroneous curvatures will reduce the sensitivity of polyp detection. The third problem is that more than 150 features are selected from each polyp candidate in the third stage of our CAD system. These high dimensional features make it difficult to learn a good decision boundary for detection classification and reduce the accuracy of predictions. Therefore, an improved CAD system for polyp detection in CTC data is proposed by introducing three new techniques. First, a scale-based scatter correction algorithm is applied to reduce pseudo-enhancement effects in the image pre-processing stage. Second, a cubic spline interpolation method is utilized to accurately estimate curvatures for initial detection generation. Third, a new dimensionality

  18. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  19. Manual versus target-controlled infusion of balanced propofol during diagnostic colonoscopy: A prospective randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Vučićević Vera

    2016-01-01

    Full Text Available Introduction. There is an increasing interest in balanced propofol sedation (BPS for colonoscopy in outpatient settings. Propofol is a potent anesthetic agent for this purpose and has a narrow therapeutic range, which increases a risk of cardiovascular and respiratory complications in case of improper administration. Objective. The aim of this study was to compare patients’ safety and comfort of endoscopists in two methods of BPS targeting deep sedation - propofol target-controlled infusion (TCI and manual intravenous titration technique (MT - during colonoscopy. Methods. This prospective randomized controlled trial included 90 patients (class I or II of the American Society of Anesthesiologists deeply sedated with propofol, coadministered with small doses of midazolam and fentanyl. Propofol was given by MT technique (45 patients or by TCI (45 patients. The following adverse effects were recorded: hypotension, hypertension, bradycardia, tachycardia, hypoxemia, bradypnea, apnea, hiccupping, and coughing, as well as endoscopist’s comfort during colonoscopy by means of a questionnaire. Results. The MT group compared to the TCI group had a lower mean arterial pressure in the 10th minute after the beginning (p = 0.017, and at the end of colonoscopy (p = 0.006, higher oxygen saturation in the fifth minute (p = 0.033, and in the 15th minute (p = 0.008 after the beginning of colonoscopy, and lower heart rate at the beginning of the procedure (p = 0.001. There were no statistically significant differences in adverse events. Endoscopist’s comfort during colonoscopy was high 95.6% in the TCI group vs. 88.9% in the MT group (p = 0.069. Conclusion. MT is clinically as stable as TCI of propofol for deep sedation during colonoscopy, and endoscopists experienced the same comfort during colonoscopy in both groups. Thus, both combinations are suitable for deep sedation during diagnostic colonoscopy.

  20. Patients' perception of colonoscopy: patients with inflammatory bowel disease and irritable bowel syndrome experience the largest burden.

    Science.gov (United States)

    Denters, Maaike J; Schreuder, Marthe; Depla, Annekatrien C T M; Mallant-Hent, Rosalie C; van Kouwen, Mariette C A; Deutekom, Marije; Bossuyt, Patrick M; Fockens, Paul; Dekker, Evelien

    2013-08-01

    Colonoscopy is a frequently performed procedure worldwide with a negative perception, leading to reluctance to undergo the procedure. Perceptions could differ depending on the specific indication for the colonoscopy. To compare patient satisfaction with the colonoscopy procedure between five different patient groups: inflammatory bowel disease (IBD), familial predisposition for cancer, adenoma/carcinoma surveillance, symptoms suggestive of cancer, and irritable bowel syndrome (IBS). A prospective questionnaire study was carried out in two regional hospitals and two tertiary teaching hospitals in the Netherlands. A total of 797 consecutive patients scheduled for colonoscopy between October 2009 and June 2010, 146 (18%) IBD, 153 (19%) adenoma or carcinoma surveillance, 104 (13%) familial predisposition, 280 (35%) symptoms suggestive of cancer, and 114 (14%) IBS-like symptoms, were included. Two questionnaires were administered: one on the day of the procedure and another 6 weeks after the procedure. The main outcome measurements were embarrassment, pain, burden, most burdensome aspect, and overall level of satisfaction. Patients with IBD and IBS reported significantly more embarrassment and burden from the bowel preparation phase (P=0.040 and 0.018, respectively) and more pain during the colonoscopy procedure (P=0.018). This difference in pain was also observed when adjusting for volume of sedation administered, familiarity with the endoscopist, duration of the colonoscopy, or whether or not an intervention was performed. All patient groups were less satisfied with the procedure at 6 weeks than directly after the colonoscopy; they recalled more embarrassment and burden, but less pain. Patient groups, defined by indication for colonoscopy, experience the colonoscopy procedure differently.

  1. Contextual Analysis of CT Scanned Pig Carcasses

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Larsen, Rasmus; Christensen, Lars Bager;

    2006-01-01

    Knowledge of the weight of tissue types in pig carcasses is generally only available after manual dissection. The use of computed tomography (CT) has demonstrated to be a promising approach to gain knowledge on the lean meat weight (Romvari, 2005), but less effort has been put into gaining...... knowledge about the weight of other tissue types from CT. Knowing the weight of individual tissue types will directly give access to other measures such as the weight of the carcass and the Lean Meat Percentage (LMP). Until now, most analyses of CT scans have been based on the Hounsfield spectra that does...... not consider the spatial context in CT scan. Applying contextual methods from the field of image analysis we hope to make a virtual dissection of pig carcasses....

  2. Eosinophilic infiltration in the colon and liver mimicking primary colon cancer with hepatic metastases on (18)F-FDG PET/CT.

    Science.gov (United States)

    Jo, Il; Won, Kyoung Sook; Choi, Byung Wook; Kim, Sung Hoon; Zeon, Seok Kil

    2013-06-01

    We describe the case of a 78-year-old man presenting with abdominal pain and a weight loss of 5 kg over 2 months. Colonoscopy and abdominal CT suggested colon cancer of hepatic flexure. F-FDG PET/CT scan showed moderate FDG uptake lesion at the hepatic flexure colon and multiple foci of FDG accumulation in the liver. These were considered as colon cancer with multiple hepatic metastases. However, the pathologic finding of colonoscopic biopsy and CT-guided liver biopsy showed only eosinophilic infiltration and no evidence of malignancy.

  3. Carbon dioxide insufflation during screening unsedated colonoscopy: a randomised clinical trial.

    Science.gov (United States)

    Szura, Miroslaw; Pach, Radoslaw; Matyja, Andrzej; Kulig, Jan

    2015-01-01

    One of the methods used to reduce pain and discomfort during colonoscopy is insufflation of carbon dioxide instead of air. However, the actual benefit of carbon dioxide insufflation is not unequivocally proven. The aim of the study was to evaluate the advantages of carbon dioxide insufflation during screening colonoscopy. A total of 200 patients undergoing screening colonoscopy between 2010 and 2011 were included in the prospective, randomized study carried out in a surgical referral center. Screening unsedated colonoscopy with either air or carbon dioxide insufflation was performed; patients were randomly assigned to air or carbon dioxide group by means of computer-generated randomization lists. All examinations were performed in an ambulatory setting with standard videocolonoscopes. The main outcomes analyzed were (a) duration of the entire procedure, (b) cecal intubation time, and (c) pain severity immediately, 15, and 60 min after the procedure. Group I included 59 women and 41 men and group II included 51 women and 49 men. The duration of the procedure was circa 10 min in both groups. Pain score values immediately and 15 min after the procedure were similar in both groups (P=0.624 and 0.305, respectively). A lower pain score was observed only after 60 min in patients insufflated with carbon dioxide (1.28 vs. 1.54, P=0.008). No pain reduction was observed in women and in obese patients (BMI>30). Carbon dioxide insufflation during unsedated screening colonoscopy does not decrease the duration of the procedure and appears to reduce pain intensity at 60 min after examination to an extent without clinical significance. The study was registered at ClinicalTrials.gov, number NCT01461564.

  4. Carbon Dioxide Insufflation in Colonoscopy Is Safe: A Prospective Trial of 347 Patients

    Directory of Open Access Journals (Sweden)

    M. Geyer

    2012-01-01

    Full Text Available Available evidence suggests that the use of CO2 insufflation in endoscopy is more comfortable for the patient. The safety of CO2 use in colonoscopy remains contentious, particularly in sedated patients. The objective of the present prospective trial was to assess the safety of CO2 colonoscopies. Methods. 109 patients from our previous randomized CO2 colonoscopy study and an additional 238 subsequent consecutive unselected patients who had a routine colonoscopy performed in a private practice were enrolled from April 2008 through September 2008. All but 2 patients were sedated. All patients were routinely monitored with transcutaneous CO2 measurement. Volumes of CO2 administered were correlated with capnographic measurements from transcutaneous monitoring. Results. Of the 347 patients examined, 57% were women; mean (SD age of participants was of 60.2 years (12.8. Mean propofol dosage was 136 mg (64 mg. Mean CO2 values were 34.7 mm Hg (5.3 at baseline, 38.9 mm Hg (5.5 upon reaching the ileum, and 36.9 mm Hg (5.0 at examination's end. Mean maximum increase of CO2 was 4.5 mm Hg (3.6. No correlation was observed between volume of CO2 administered and increase in level of CO2 (correlation coefficient: 0.01; P value: 0.84. No complications were observed. Conclusions. The present prospective study, which was based on one of the largest sedated patient sample reported to date in this setting, provides compelling evidence that CO2 insufflation in colonoscopy is safe and unassociated with relevant increases in transcutaneously measured levels of CO2.

  5. Endovascular Treatment of Active Splenic Bleeding After Colonoscopy: A Systematic Review of the Literature

    Energy Technology Data Exchange (ETDEWEB)

    Corcillo, Antonella, E-mail: antonella.corcillo@chuv.ch [Centre Hospitalier Universitaire Vaudois (CHUV), Departement de Medecine Interne (Switzerland); Aellen, Steve, E-mail: steve.aellen@hopitalvs.ch; Zingg, Tobias [Centre Hospitalier Universitaire Vaudois (CHUV), Service de Chirurgie Viscerale (Switzerland); Bize, Pierre [Centre Hospitalier Universitaire Vaudois (CHUV), Departement de Radiologie Interventionnelle (Switzerland); Demartines, Nicolas [Centre Hospitalier Universitaire Vaudois (CHUV), Service de Chirurgie Viscerale (Switzerland); Denys, Alban [Centre Hospitalier Universitaire Vaudois (CHUV), Departement de Radiologie Interventionnelle (Switzerland)

    2013-10-15

    Purpose: Colonoscopy is reported to be a safe procedure that is routinely performed for the diagnosis and treatment of colorectal diseases. Splenic rupture is considered to be a rare complication with high mortality and morbidity that requires immediate diagnosis and management. Nonoperative management (NOM), surgical treatment (ST), and, more recently, proximal splenic artery embolization (PSAE) have been proposed as treatment options. The goal of this study was to assess whether PSAE is safe even in high-grade ruptures. Methods: We report two rare cases of post colonoscopy splenic rupture. A systematic review of the literature from 2002 to 2010 (first reported case of PSAE) was performed and the three types of treatment compared. Results: All patients reviewed (77 of 77) presented with intraperitoneal hemorrhage due to isolated splenic trauma. Splenic rupture was high-grade in most patients when grading was possible. Six of 77 patients (7.8 %) were treated with PSAE, including the 2 cases reported herein. Fifty-seven patients (74 %) underwent ST. NOM was attempted first in 25 patients with a high failure rate (11 of 25 [44 %]) and requiring a salvage procedure, such as PSAE or ST. Previous surgery (31 of 59 patients), adhesions (10 of 13), diagnostic colonoscopies (49 of 71), previous biopsies or polypectomies (31 of 57) and female sex (56 of 77) were identified as risk factors. In contrast, splenomegaly (0 of 77 patients), medications that increase the risk of bleeding (13 of 30) and difficult colonoscopies (16 of 51) were not identified as risk factors. PSAE was safe and effective even in elderly patients with comorbidities and those taking medications that increase the risk of bleeding, and the length of the hospital stay was similar to that after ST. Conclusion: We propose a treatment algorithm based on clinical and radiological criteria. Because of the high failure rate after NOM, PSAE should be the treatment of choice to manage grade I through IV splenic

  6. Virtual Reality

    Directory of Open Access Journals (Sweden)

    Bhavana Gupta

    2012-10-01

    Full Text Available An artificial environment created with co mputer hardware and software and presented to the user in such a way that it appears and feels like a real environment. To "enter" a virtual reality, a user does special gloves, earphones, and goggles, all of which receive their input from the computer system. In this way, at least three of the five senses are controlled by the computer. In addition to feeding sensory input to the user, the devices also monitor the user's actions

  7. The effect of virtual endoscopy simulator training on novices: a systematic review.

    Directory of Open Access Journals (Sweden)

    Weiguang Qiao

    Full Text Available BACKGROUND: Advances in virtual endoscopy simulators have paralleled an interest in medical simulation for gastrointestinal endoscopy training. OBJECTIVE: The primary objective was to determine whether the virtual endoscopy simulator training could improve the performance of novices. DESIGN: A systematic review. SETTING: Randomized controlled trials (RCTs that compared virtual endoscopy simulator training with bedside teaching or any other intervention for novices were collected. PATIENTS: Novice endoscopists. INTERVENTIONS: The PRISMA statement was followed during the course of the research. The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and ScienceDirect were searched (up to July 2013. Data extraction and assessment were independently performed. MAIN OUTCOME MEASUREMENTS: Independent procedure completion, total procedure time and required assistance. RESULTS: Fifteen studies (n = 354 were eligible for inclusion: 9 studies designed for colonoscopy training, 6 for gastroscopy training. For gastroscopy training, procedure completed independently was reported in 87.7% of participants in simulator training group compared to 70.0% of participants in control group (1 study; 22 participants; RR 1.25; 95% CI 1.13-1.39; P<0.0001. For colonoscopy training, procedure completed independently was reported in 89.3% of participants in simulator training group compared to 88.9% of participants in control group (7 study; 163 participants; RR 1.10; 95% CI 0.88-1.37; P = 0.41; I(2 = 85%. LIMITATIONS: The included studies are quite in-homogeneous with respect to training schedule and procedure. CONCLUSIONS: Virtual endoscopy simulator training might be effective for gastroscopy, but so far no data is available to support this for colonoscopy.

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and accurate. A ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate ...

  10. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, ... the body being studied. top of page How is the CT scan performed? The technologist begins by ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ... after the procedure? CT exams are generally painless, fast and easy. With multidetector CT, the amount of ...

  12. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen ... and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a ...

  13. Abdominal and Pelvic CT

    Science.gov (United States)

    ... Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen ... and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a ...

  14. Life-threatening gastrointestinal system bleeding in Hodgkin disease: multidetector CT findings and review of the literature.

    Science.gov (United States)

    Akpinar, Erhan; Türkbey, Bariş; Cil, Barbaros Erhan; Canyiğit, Murat; Dündar, Ziya; Balkanci, Ferhun

    2007-06-01

    Acute lower gastrointestinal system (GIS) bleeding is a life-threatening condition. Immediate determination of the origin of the bleeding is crucial, since hemostatic management must be initiated as rapidly as possible. Colonoscopy, radionuclide studies, and conventional angiography are considered the most important methods for assessing the origin of the bleeding. There are few published reports about the feasibility of computed tomography (CT) in acute GIS bleeding. We present multidetector CT (MDCT) findings in a case of Hodgkin disease status one month post-chemotherapy (CHOP protocol; cyclophosphamide, doxorubicin, vincristine, prednisone) that presented with acute lower GIS bleeding.

  15. Virtual screening of virtual libraries.

    Science.gov (United States)

    Green, Darren V S

    2003-01-01

    Virtual screening of virtual libraries (VSVL) is a rapidly changing area of research. Great efforts are being made to produce better algorithms, selection methods and infrastructure. Yet, the number of successful examples in the literature is not impressive, although the quality of work certainly is high. Why is this? One reason is that these methods tend to be applied at the lead generation stage and therefore there is a large lead-time before successful examples appear in the literature. However, any computational chemist would confirm that these methods are successful and there exists a glut of start-up companies specialising in virtual screening. Moreover, the scientific community would not be focussing so much attention on this area if it were not yielding results. Even so, the paucity of literature data is certainly a hindrance to the development of better methods. The VSVL process is unique within the discovery process, in that it is the only method that can screen the > 10(30) genuinely novel molecules out there. Already, some VSVL methods are evaluating 10(13) compounds, a capacity that high throughput screening can only dream of. There is a huge potential advantage for the company that develops efficient and effective methods, for lead generation, lead hopping and optimization of both potency and ADME properties. To do this, it requires more than the software, it requires confidence to exploit the methodology, to commit synthesis on the basis of it, and to build this approach into the medicinal chemistry strategy. It is a fact that these tools remain quite daunting for the majority of scientists working at the bench. The routine use of these methods is not simply a matter of education and training. Integration of these methods into accessible and robust end user software, without dilution of the science, must be a priority. We have reached a coincidence, where several technologies have the required level of maturity predictive computational chemistry

  16. Plexiform neurofibromatosis of the mediastinum: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chul Joong; Lee, Min Jin; Oh, Yu Whan; Suh, Won Hyuck; Lee, Yung Suk [College of Medicine, Korea University, Seoul (Korea, Republic of)

    1994-11-15

    Plexiform neurofibroma usually occur in the neck, pelvis and extremities, but they may seen virtually at any location, including the thorax. To evaluate the findings and the role of CT in plexiform neurofibromatosis of the mediastinum. We retrospectively reviewed the clinical results and thoracic CT scans of five patients with pathologically proved plexiform neurofibromatosis of the mediastinum. The CT scans were reviewed with attention to the distribution of the lesions, appearance and attenuation of mediastinal lesions, enhancement pattern after intravenous contrast infusion and associated findings such as intercostal neurofibroma. In all five patients CT scans demonstrated fusiform low attenuated masses which were oriented longitudinally and extended over multiple contiguous scans along the distribution of major mediastinal nerves. In four patients, mediastinal lesions appeared infiltrative, obliterating adjacent mediastinal fat plane. One patient had well defined fusiform masses along the major mediastinal nerves. Postcontrast enhanced CT scans revealed slight central enhancement in two patient and no contrast enhancement in three patients. Associated findings such as neurofibromas of intercostal nerves and sympathetic trunk, or subcutaneous neurofibromas were detected on CT scans in all five patients. Characteristic CT findings of low attenuation masses along the major mediastinal nerves are helpful to differentiate plexiform neurofibromatosis from mediastinal lymphadenopathy and to prevent from misreading as a malignant disease.

  17. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    We collect diverse philosophical analyses of the issues and problems clustering around trust online with specific attention to establishing trust in virtual environments. The book moves forward important discussions of how virtual worlds and virtuality are to be defined and understood; the role o...... by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....

  18. Insurance Coverage for CT Colonography Screening: Impact on Overall Colorectal Cancer Screening Rates.

    Science.gov (United States)

    Smith, Maureen A; Weiss, Jennifer M; Potvien, Aaron; Schumacher, Jessica R; Gangnon, Ronald E; Kim, David H; Weeth-Feinstein, Lauren A; Pickhardt, Perry J

    2017-09-01

    Purpose To compare overall colorectal cancer (CRC) screening rates for patients who were eligible and due for CRC screening and who were with and without insurance coverage for computed tomographic (CT) colonography for CRC screening. Materials and Methods The institutional review board approved this retrospective cohort study, with a waiver of consent. This study used longitudinal electronic health record data from 2005 through 2010 for patients managed by one of the largest multispecialty physician groups in the United States. It included 33 177 patients under age 65 who were eligible and due for CRC screening and managed by the participating health system. Stratified Cox regression models provided propensity-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between CT colonography coverage and CRC screening. Results After adjustment, patients who had insurance coverage for CT colonography and were due for CRC screening had a 48% greater likelihood of being screened for CRC by any method compared with those without coverage who were due for CRC screening (HR, 1.48; 95% CI: 1.41, 1.55). Similarly, patients with CT colonography coverage had a greater likelihood of being screened with CT colonography (HR, 8.35; 95% CI: 7.11, 9.82) and with colonoscopy (HR, 1.38; 95% CI: 1.31, 1.45) but not with fecal occult blood test (HR, 1.00; 95% CI: 0.91, 1.10) than those without such insurance coverage. Conclusion Insurance coverage of CT colonography for CRC screening was associated with a greater likelihood of a patient being screened and a greater likelihood of being screened with a test that helps both to detect cancer and prevent cancer from developing (CT colonography or colonoscopy). (©) RSNA, 2017.

  19. Realidad virtual y materialidad

    OpenAIRE

    Pérez Herranz, Fernando Miguel

    2009-01-01

    1. Fenomenología de partida: Real / Simbólico / Imaginario 2. Realidad 3. Virtual 3.1. Virtual / real / posible / probable 3.2. Los contextos de la realidad virtual A) REALIDAD VIRTUAL INMERSIVA B) REALIDAD