Follow-up after stent insertion in the tracheobronchial tree: role of helical computed tomography in comparison with fiberoptic bronchoscopy

International Nuclear Information System (INIS)

Ferretti, G.R.; Kocier, M.; Calaque, O.; Coulomb, M.; Arbib, F.; Pison, C.; Righini, C.

2003-01-01

The aim of this study was to compare helical CT with fiberoptic bronchoscopy findings to appraise the medium-term results of proximal-airways stenting. Twenty-five patients with 28 endobronchial metallic stents inserted for local advanced malignancy (n=13) or benign diseases (n=12) underwent follow-up CT from 3 days to 50 months (mean 8 months). All studies were obtained using helical CT with subsequent multiplanar reformation and three-dimensional reconstruction including virtual bronchoscopy. The location, shape, and patency of stents and adjacent airway were assessed. The results of CT were compared with the results of fiberoptic bronchoscopy obtained with a mean delay of 2.5 days (SD 9 days) after CT scan. Twelve stents (43%) remained in their original position, patent and without deformity. Sixteen stents were associated with local complications: migration (n=6); external compression with persistent stenosis (n=4); local recurrence of malignancy (n=4); fracture (n=1); and non-congruence between the airway and the stent (n=1). The CT demonstrated all the significant abnormalities demonstrated at fiberoptic bronchoscopy except two moderate stenoses (20%) related to granulomata at the origin of the stent. Ten of 14 stents inserted for benign conditions were without complications as compared with 2 of 14 in malignant conditions (p=0.008). Computed tomography is an accurate noninvasive method for evaluating endobronchial stents. The CT is a useful technique for follow-up of patients who have undergone endobronchial stenting. (orig.)

Virtual bronchoscopy, importance of the method, application and prospects for tumors of the trachea and bronchi

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M. A. Mitev

2017-09-01

Full Text Available Virtual bronchoscopy (VB is 3-dimensional computer-generated technology, creating endobronchial images from spiral CT data. The study aims to present summarized results from researches of different foreign authors about the advantages of VB, the possibilities for its application and the effectiveness of its use in routine practice in the diagnosis of tumors of the trachea and bronchi. The three-dimensional model of the tracheobronchial tree allows assessment of the airways from inside. The majority of the examined studies relate to the diagnosis of new formations of the respiratory tract, preparation for surgery, assessment of the results of surgery, etc. VB is a noninvasive method allowing to examine the smallest bronchi. Relatively few studies in Bulgaria as well as the ensured during recent years new modern equipment for VB and MDCT, provide great opportunities for making VB examinations to study the effectiveness and its wide application in daily X-ray practice.

Application of the Virtual Bronchoscopy in Children with Suspected Aspiration of the Foreign Body - Case Report

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Kostic Gordana

2016-12-01

Full Text Available In diagnosing the aspiration of the foreign body (AFB in children most important are: medical history, clinical signs and positive radiography of the lungs. Common dilemmas in the diff erential diagnosis are life-threatening asthma attacks or difficult pneumonia. Conventional rigid bronchoscopy (RB is not recommended as a routine method. Virtual bronchoscopy (VB can be a diagnostic tool for solving dilemmas. Fiber-optic bronchoscopy (FOB has a therapeutic stake in severe cases. Herein, we describe a girl, at the age of 6, who was hospitalized due to rapid bronchoconstriction and based on the anamnesis, clinical symptoms and physical fi ndings the suspicion was that she aspirated the foreign body. Due to the poor general condition and possible sequel, the idea of RB was dropped out. Multidetector computed tomography of the chest and VB was performed and AFB was not found. Due to positive epidemiological situation, virus H1N1 was excluded. FOB established that the foreign body does not exist in the airways. During bronchoscopy numerous castings are aspirated from the peripheral airways which lead to faster final recovery. With additional procedures, the diagnosis of asthma was confirmed and for girl that was the first attack. Along with inhaled corticosteroids as prevention she feels well.

Electromagnetic navigation diagnostic bronchoscopy for small peripheral lung lesions.

Science.gov (United States)

Makris, D; Scherpereel, A; Leroy, S; Bouchindhomme, B; Faivre, J-B; Remy, J; Ramon, P; Marquette, C-H

2007-06-01

The present study prospectively evaluated the diagnostic yield and safety of electromagnetic navigation-guided bronchoscopy biopsy, for small peripheral lung lesions in patients where standard techniques were nondiagnostic. The study was conducted in a tertiary medical centre on 40 consecutive patients considered unsuitable for straightforward surgery or computed tomography (CT)-guided transthoracic needle aspiration biopsy, due to comorbidities. The lung lesion diameter was mean+/-sem 23.5+/-1.5 mm and the depth from the visceral-costal pleura was 14.9+/-2 mm. Navigation was facilitated by an electromagnetic tracking system which could detect a position sensor incorporated into a flexible catheter advanced through a bronchoscope. Information obtained during bronchoscopy was superimposed on previously acquired CT data. Divergence between CT data and data obtained during bronchoscopy was calculated by the system's software as a measure of navigational accuracy. All but one of the target lesions was reached and the overall diagnostic yield was 62.5% (25-40). Diagnostic yield was significantly affected by CT-to-body divergence; yield was 77.2% when estimated divergence was drainage was required in one case. Electromagnetic navigation-guided bronchoscopy has the potential to improve the diagnostic yield of transbronchial biopsies without additional fluoroscopic guidance, and may be useful in the early diagnosis of lung cancer, particularly in nonoperable patients.

Utility of multidetector row computed tomography and virtual bronchoscopy in evaluation of hemoptysis due to lung cancer

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Sherif A.A. Mohamed

2016-01-01

Conclusion: MDCT angiography is a useful and non invasive method that allows a rapid and detailed identification of abnormal vasculature responsible for hemoptysis in patients with lung cancer. MDCT-generated virtual bronchoscopy is an accurate, and non invasive method for evaluating obstructions, endoluminal masses, and external compressions in patients with hemoptysis due to lung cancer.

Training on a new, portable, simple simulator transfers to performance of complex bronchoscopy procedures

DEFF Research Database (Denmark)

Loumann Krogh, Charlotte; Konge, Lars; Bjurström, Johanna Margareta

2013-01-01

Virtual-reality (VR) simulation provides a safe and effective learning environment prior to practicing on patients. However, existing bronchoscopy simulators are expensive and not easily portable.......Virtual-reality (VR) simulation provides a safe and effective learning environment prior to practicing on patients. However, existing bronchoscopy simulators are expensive and not easily portable....

Multimodal system for the planning and guidance of bronchoscopy

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Higgins, William E.; Cheirsilp, Ronnarit; Zang, Xiaonan; Byrnes, Patrick

2015-03-01

Many technical innovations in multimodal radiologic imaging and bronchoscopy have emerged recently in the effort against lung cancer. Modern X-ray computed-tomography (CT) scanners provide three-dimensional (3D) high-resolution chest images, positron emission tomography (PET) scanners give complementary molecular imaging data, and new integrated PET/CT scanners combine the strengths of both modalities. State-of-the-art bronchoscopes permit minimally invasive tissue sampling, with vivid endobronchial video enabling navigation deep into the airway-tree periphery, while complementary endobronchial ultrasound (EBUS) reveals local views of anatomical structures outside the airways. In addition, image-guided intervention (IGI) systems have proven their utility for CT-based planning and guidance of bronchoscopy. Unfortunately, no IGI system exists that integrates all sources effectively through the complete lung-cancer staging work flow. This paper presents a prototype of a computer-based multimodal IGI system that strives to fill this need. The system combines a wide range of automatic and semi-automatic image-processing tools for multimodal data fusion and procedure planning. It also provides a flexible graphical user interface for follow-on guidance of bronchoscopy/EBUS. Human-study results demonstrate the system's potential.

Assessment of competence in simulated flexible bronchoscopy using motion analysis

DEFF Research Database (Denmark)

Collela, Sara; Svendsen, Morten Bo Søndergaard; Konge, Lars

2015-01-01

Background: Flexible bronchoscopy should be performed with a correct posture and a straight scope to optimize bronchoscopy performance and at the same time minimize the risk of work-related injuries and endoscope damage. Objectives: We aimed to test whether an automatic motion analysis system could...... intermediates and 9 experienced bronchoscopy operators performed 3 procedures each on a bronchoscopy simulator. The Microsoft Kinect system was used to automatically measure the total deviation of the scope from a perfectly straight, vertical line. Results: The low-cost motion analysis system could measure...... with the performance on the simulator (virtual-reality simulator score; p analysis system could discriminate between different levels of experience. Automatic feedback on correct movements during self-directed training on simulators might help new bronchoscopists learn how to handle...

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

International Nuclear Information System (INIS)

Buchbender, Christian; Heusner, Till A.; Treffert, Jon; Lehnerdt, Goetz; Mattheis, Stefan; Geiger, Bernhard; Bockisch, Andreas; Forsting, Michael; Antoch, Gerald

2012-01-01

The aim of this study was to evaluate whether a virtual 3-D 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 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 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 18 F-FDG PET/CT panendoscopies was 145 ± 98 s. Virtual 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.)

Bronchoscopy as a supplement to computed tomography in patients with haemoptysis may be unnecessary

DEFF Research Database (Denmark)

Nielsen, Klaus; Gottlieb, Magnus; Colella, Sara

2016-01-01

. RESULTS: A total of 326 patients were included in the study (mean age 60.5 [SD 15.3] years, 63.3% male). The most common aetiologies of haemoptysis were cryptogenic (52.5%), pneumonia (16.3%), emphysema (8.0%), bronchiectasis (5.8%) and lung cancer (4.0%). In patients diagnosed with lung cancer......BACKGROUND: Haemoptysis is a common symptom and can be an early sign of lung cancer. Careful investigation of patients with haemoptysis may lead to early diagnosis. The strategy for investigation of these patients, however, is still being debated. OBJECTIVES: We studied whether the combination......, bronchoscopy, CT and the combination of bronchoscopy and CT had a sensitivity of 0.61, 0.92 (pemphysema and bronchiectasis. Bronchoscopy did...

Virtual bronchoscopy-guided transbronchial biopsy for aiding the diagnosis of peripheral lung cancer

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Iwano, Shingo, E-mail: iwano45@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 4668550, Aichi (Japan); Imaizumi, Kazuyoshi [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 4668550 (Japan); Okada, Tohru [Research Center for Charged Particle Therapy, National Institute of Radiological Science, 4-9-1 Anagawa, Inage-ku, Chiba 2638555 (Japan); Hasegawa, Yoshinori [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 4668550 (Japan); Naganawa, Shinji [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Shouwa-ku, Nagoya 4668550, Aichi (Japan)

2011-07-15

Objective: The aim of this study was to evaluate the clinical value of virtual bronchoscopy (VB) in aiding diagnosis of peripheral lung cancer by transbronchial biopsy (TBB). In addition, we sought to systematically analyze the factors that affect the diagnostic sensitivity of VB-guided TBB for the evaluation of peripheral lung cancers. Materials and methods: A hundred and twenty-two peripheral lung cancers from 122 patients (82 men and 40 women, 38-84 years; median 68.5 years) who were performed VB-guided TBB were evaluated retrospectively. VB was reconstructed from 1- or 0.5-mm slice thickness images of multi-detector CT (MDCT). Experienced pulmonologists inserted the conventional and ultrathin bronchoscopes into the target bronchus under direct vision following the VB image. Results: A definitive diagnosis was established by VB-guided TBB in 96 lesions (79%). The diagnostic sensitivity of small pulmonary lesions {<=}30 mm in maximal diameter (71%) was significantly lower than that of lesions >30 mm (91%, p = 0.008). For small pulmonary lesions {<=}30 mm (n = 76), internal opacity of the lesion was the independent predictor of diagnostic sensitivity by VB-guided TBB, and the non-solid type lung cancers were significantly lower than the solid type and part-solid type lung cancers for diagnostic sensitivity (odds ratio = 0.161; 95% confidence interval = 0.033-0.780; p = 0.023). Conclusion: Use of an ultrathin bronchoscope and simulation with VB reconstructed by high quality MDCT images is thought to improve pathological diagnosis of peripheral lung cancers, especially for solid and partly solid types. For small pulmonary lesions {<=}30 mm, the lesion internal opacity is a significant factor for predicting the diagnostic sensitivity, and the sensitivity was low for small non-solid type of lung cancers.

Flexible Bronchoscopy.

Science.gov (United States)

Miller, Russell J; Casal, Roberto F; Lazarus, Donald R; Ost, David E; Eapen, George A

2018-03-01

Flexible bronchoscopy has changed the course of pulmonary medicine. As technology advances, the role of the flexible bronchoscope for both diagnostic and therapeutic indications is continually expanding. This article reviews the historical development of the flexible bronchoscopy, fundamental uses of the flexible bronchoscope as a tool to examine the central airways and obtain diagnostic tissue, and the indications, complications, and contraindications to flexible bronchoscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

Pleural Dye Marking Using Radial Endobronchial Ultrasound and Virtual Bronchoscopy before Sublobar Pulmonary Resection for Small Peripheral Nodules.

Science.gov (United States)

Lachkar, Samy; Baste, Jean-Marc; Thiberville, Luc; Peillon, Christophe; Rinieri, Philippe; Piton, Nicolas; Guisier, Florian; Salaun, Mathieu

2018-01-01

Minimally invasive surgery of pulmonary nodules allows suboptimal palpation of the lung compared to open thoracotomy. The objective of this study was to assess endoscopic pleural dye marking using radial endobronchial ultrasound (r-EBUS) and virtual bronchoscopy to localize small peripheral lung nodules immediately before minimally invasive resection. The endoscopic procedure was performed without fluoroscopy, under general anesthesia in the operating room immediately before minimally invasive surgery. Then, 1 mL of methylene blue (0.5%) was instilled into the guide sheath, wedged in the subpleural space. Wedge resection or segmentectomy were guided by visualization of the dye on the pleural surface. Contribution of dye marking to the surgical procedure was rated by the surgeon. Twenty-five nodules, including 6 ground glass opacities, were resected in 22 patients by video-assisted thoracoscopic wedge resection (n = 11) or robotic-assisted thoracoscopic surgery (10 segmentectomies and 1 wedge resection). The median greatest diameter of nodules was 8 mm. No conversion to open thoracotomy was needed. The endoscopic procedure added an average 10 min to surgical resection. The dye was visible on the pleural surface in 24 cases. Histological diagnosis and free margin resection were obtained in all cases. Median skin-to-skin operating time was 90 min for robotic segmentectomy and 40 min for video-assisted wedge resection. The same operative precision was considered impossible by the surgeon without dye marking in 21 cases. Dye marking using r-EBUS and virtual bronchoscopy can be easily and safely performed to localize small pulmonary nodules immediately before minimally invasive resection. © 2018 S. Karger AG, Basel.

Bronchoscopy Simulation Training as a Tool in Medical School Education.

Science.gov (United States)

Gopal, Mallika; Skobodzinski, Alexus A; Sterbling, Helene M; Rao, Sowmya R; LaChapelle, Christopher; Suzuki, Kei; Litle, Virginia R

2018-07-01

Procedural simulation training is rare at the medical school level and little is known about its usefulness in improving anatomic understanding and procedural confidence in students. Our aim is to assess the impact of bronchoscopy simulation training on bronchial anatomy knowledge and technical skills in medical students. Medical students were recruited by email, consented, and asked to fill out a survey regarding their baseline experience. Two thoracic surgeons measured their knowledge of bronchoscopy on a virtual reality bronchoscopy simulator using the Bronchoscopy Skills and Tasks Assessment Tool (BSTAT), a validated 65-point checklist (46 for anatomy, 19 for simulation). Students performed four self-directed training sessions of 15 minutes per week. A posttraining survey and BSTAT were completed afterward. Differences between pretraining and posttraining scores were analyzed with paired Student's t tests and random intercept linear regression models accounting for baseline BSTAT score, total training time, and training year. The study was completed by 47 medical students with a mean training time of 81.5 ± 26.8 minutes. Mean total BSTAT score increased significantly from 12.3 ± 5.9 to 48.0 ± 12.9 (p training time and frequency of training did not have a significant impact on level of improvement. Self-driven bronchoscopy simulation training in medical students led to improvements in bronchial anatomy knowledge and bronchoscopy skills. Further investigation is under way to determine the impact of bronchoscopy simulation training on future specialty interest and long-term skills retention. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Electromagnetic Navigational Bronchoscopy versus CT-guided Percutaneous Sampling of Peripheral Indeterminate Pulmonary Nodules: A Cohort Study.

Science.gov (United States)

Bhatt, Kavita M; Tandon, Yasmeen K; Graham, Ruffin; Lau, Charles T; Lempel, Jason K; Azok, Joseph T; Mazzone, Peter J; Schneider, Erika; Obuchowski, Nancy A; Bolen, Michael A

2018-03-01

Purpose To compare the diagnostic yield and complication rates of electromagnetic navigational bronchoscopic (ENB)-guided and computed tomography (CT)-guided percutaneous tissue sampling of lung nodules. Materials and Methods Retrospectively identified were 149 patients sampled percutaneously with CT guidance and 146 patients who underwent ENB with transbronchial biopsy of a lung lesion between 2013 and 2015. Clinical data, incidence of complications, and nodule pathologic analyses were assessed through electronic medical record review. Lung nodule characteristics were reviewed through direct image analysis. Molecular marker studies and pathologic analyses from surgical excision were reviewed when available. Multiple-variable logistic regression models were built to compare the diagnostic yield and complication rates for each method and for different patient and disease characteristics. Results CT-guided sampling was more likely to be diagnostic than ENB-guided biopsy (86.0% [129 of 150] vs 66.0% [99 of 150], respectively), and this difference remained significant even after adjustments were made for patient and nodule characteristics (P guided sampling (P guided sampling, 88.9% [32 of 36]; CT-guided sampling, 82.0% [41 of 50]). The two groups had similar rates of major complications (symptomatic hemorrhage, P > .999; pneumothorax requiring chest tube and/or admission, P = .417). Conclusion CT-guided transthoracic biopsy provided higher diagnostic yield in the assessment of peripheral pulmonary nodules than navigational bronchoscopy with a similar rate of clinically relevant complications. © RSNA, 2017 Online supplemental material is available for this article.

Bronchoscopy in Rural Areas?

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Reidar Berntsen

2012-01-01

Full Text Available Quality of bronchoscopy performed by one single pulmonologist in a scarcely populated subarctic area was compared to the guidelines provided by the British Thoracic Society (BTS. 103 patients underwent bronchoscopy. Diagnostic yield was increased to 76.6% when the first bronchoscopy was supplemented by bronchial washing fluid and brush cytology and to 86.7% (BTS guidelines >80% after a second bronchoscopy. Median time from referral to bronchoscopy was 10 days and 8 days from positive bronchoscopy to operative referral to another hospital. 1% of patients that underwent transbronchial lung biopsy had minor complications. One pulmonologist had rate of correct diagnosis based on visible endobronchial tumors that was comparable to the rates of numerous pulmonologists at larger centers performing the same procedure. Time delay was short. Rate of complications was comparable. Bronchoscopy performed by one pulmonologist alone could, in organized settings, be carried out at local hospitals in areas of scattered settlement.

Virtual gastroscopy using spiral CT in gastric lesions

International Nuclear Information System (INIS)

Shin, Sang Soo; Kang, Heoung Keun; Jeong, Yong Yeon; Yoon, Man Won; Song, Sang Gook; Jeong, Gwang Woo

1998-01-01

To compare virtual gastroscopy using spiral CT with conventional endoscopy for the detection and evaluation of gastric lesions. During a previous six-month period, 30 patients with pathologically-proven gastric lesions underwent conventional endoscopy and virtual gastroscopy using spiral CT. There were 18 cases of advanced gastric carcinoma, eight benign ulcers, and four submucosal tumors(two leiomyomas, two lymphomas). Source images of virtual gastroscopy were three-dim-ensionally reconstructed within an Advantage Windows Workstation and virtual gastroscopic images were obtained using Navigator Software. On analysis, images were graded according to their quality(excellent, good, poor). Virtual gastroscopic images were interpreted by two radiologists blinded to conventional endoscopic findings, and were subsequently compared with endoscopic findings in terms of detectability and findings. In the cases of advanced gastric carcinoma, lesions were classified according to Borrmann's system. For virtual gastroscopy, overall image quality was excellent in 21 cases(70%), good in five(17%), and poor in four(13%). Lesions were detected in 25 cases(83%). Among the 18 advanced gastric carcinomas, virtual gastroscopy image quality was excellent in 14 cases(78%), good in two(11%), and poor in two(11%). Lesions were detected in 16 cases(89%). Two Borrmann type IV cases were not detected. Among the eight benign ulcers, virtual gastroscopy image quality was excellent in three cases(38%), good in three(38%), and poor in two(25%). The detection of lesion was possible in five cases(63%). In all submucosal tumors, virtual gastroscopy image quality was excellent. Lesions were detected in all cases. Virtual gastroscopy using spiral CT is safe and noninvasive, and for the evaluation of gastric lesions may be complementary to axial CT. It successfully detects gastric lesions, and in depicting the pattern of gastric folds its image quality is excellent.=20

Virtual CT-colonoscopy. Examination technique, limitations, and prospects

International Nuclear Information System (INIS)

Springer, P.; Dessl, A.; Giacomuzzi, S.M.; Stoehr, B.; Stoeger, A.; Bodner, G.; Buchberger, W.

1997-01-01

Virtual CT-colonoscopy is a post-processing method which allows for reconstruction of inner bowel surface structures from helical CT datasets. The reconstructed images simulate the views which are known from fiberoptic endoscopy. Since colorectal cancer is the second main cause of death in USA and Europe today and since recent screening recommendations are often ignored by the public, a non-invasive or minimal-invasive procedure for colonic evaluation would offer some benefits. Virtual CT-colonoscopy generally involves three essential steps: patient preparation with cleansing of the bowel and administration of an air enema, helical CT-examination by using appropriate scan parameters, and interactive 3D rendering of the volume dataset. Although recent studies have demonstrated that polypoid lesions of about 5 mm size are well detectable and although virtual colonoscopy offers many advantages over fiberoptic endoscopy, some technical and clinical limitations must still be noted. Thus, the current inability of virtual colonoscopy to provide texture and color leads to problems in identifying flat lesions; the presence of retained or adherent fecal matter may result to false positive diagnosis and collapsed segments of bowel may cause problems as they cannot subsequently be evaluated during image reconstruction. Virtual endoscopy is still in its infancy and further technical and clinical development are necessary. (orig./AJ) [de

Diagnosis of tracheal instability: inspiratory and expiratory spiral CT and cine CT

International Nuclear Information System (INIS)

Heussel, C.P.; Thelen, M.; Kauczor, H.U.; Hafner, B.; Lill, J.

2000-01-01

Purpose: In tracheo- and bronchomalacia, localization and determination of collapse is necessary for planning a surgical procedure. We compared inspiratory and spiral CT, cine CT, and bronchoscopy and evaluated the relevance of each method. Methods: Seventeen patients with suspected or verified tracheal stonosis or collapse underwent paired inspiratory and exspiratory spiral CT and cine CT during continuous respiration (temporal increment 100 ms). The tracheal cross-sectional area was calculated and compared. Results: In addition to bronchoscopy, further information concerning localization, extent, collapse, stability of the tracheal wall, distal portions of the stenosis, and extraluminal compressions was obtained. A significantly higher degree of tracheal collapse was seen using cine CT compared to paired spiral CT (p [de

Virtual reality simulation of basic pulmonary procedures

DEFF Research Database (Denmark)

Konge, Lars; Arendrup, Henrik; von Buchwald, Christian

2011-01-01

Background: Virtual reality (VR) bronchoscopy simulators have been available for more than a decade, and have been recognized as an important aid in bronchoscopy training. The existing literature has only examined the role of VR simulators in diagnostic bronchoscopy. The aim of this study...

SU-C-BRA-07: Virtual Bronchoscopy-Guided IMRT Planning for Mapping and Avoiding Radiation Injury to the Airway Tree in Lung SAbR

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Sawant, A; Modiri, A; Bland, R; Yan, Y; Ahn, C; Timmerman, R [University of Texas SouthWestern Medical Center, Dallas, TX (United States)

2015-06-15

Purpose: Post-treatment radiation injury to central and peripheral airways is a potentially important, yet under-investigated determinant of toxicity in lung stereotactic ablative radiotherapy (SAbR). We integrate virtual bronchoscopy technology into the radiotherapy planning process to spatially map and quantify the radiosensitivity of bronchial segments, and propose novel IMRT planning that limits airway dose through non-isotropic intermediate- and low-dose spillage. Methods: Pre- and ∼8.5 months post-SAbR diagnostic-quality CT scans were retrospectively collected from six NSCLC patients (50–60Gy in 3–5 fractions). From each scan, ∼5 branching levels of the bronchial tree were segmented using LungPoint, a virtual bronchoscopic navigation system. The pre-SAbR CT and the segmented bronchial tree were imported into the Eclipse treatment planning system and deformably registered to the planning CT. The five-fraction equivalent dose from the clinically-delivered plan was calculated for each segment using the Universal Survival Curve model. The pre- and post-SAbR CTs were used to evaluate radiation-induced segmental collapse. Two of six patients exhibited significant segmental collapse with associated atelectasis and fibrosis, and were re-planned using IMRT. Results: Multivariate stepwise logistic regression over six patients (81 segments) showed that D0.01cc (minimum point dose within the 0.01cc receiving highest dose) was a significant independent factor associated with collapse (odds-ratio=1.17, p=0.010). The D0.01cc threshold for collapse was 57Gy, above which, collapse rate was 45%. In the two patients exhibiting segmental collapse, 22 out of 32 segments showed D0.01cc >57Gy. IMRT re-planning reduced D0.01cc below 57Gy in 15 of the 22 segments (68%) while simultaneously achieving the original clinical plan objectives for PTV coverage and OAR-sparing. Conclusion: Our results indicate that the administration of lung SAbR can Result in significant injury to

Intrathoracic Airway Tree Segmentation from CT Images Using a Fuzzy Connectivity Method

Directory of Open Access Journals (Sweden)

Fereshteh Yousefi Rizi

2009-03-01

Full Text Available Introduction: Virtual bronchoscopy is a reliable and efficient diagnostic method for primary symptoms of lung cancer. The segmentation of airways from CT images is a critical step for numerous virtual bronchoscopy applications. Materials and Methods: To overcome the limitations of the fuzzy connectedness method, the proposed technique, called fuzzy connectivity - fuzzy C-mean (FC-FCM, utilized the FCM algorithm. Then, hanging-togetherness of pixels was handled by employing a spatial membership function. Another problem in airway segmentation that had to be overcome was the leakage into the extra-luminal regions due to the thinness of the airway walls during the process of segmentation. Results:   The result shows an accuracy of 92.92% obtained for segmentation of the airway tree up to the fourth generation. Conclusion:  We have presented a new segmentation method that is not only robust regarding the leakage problem but also functions more efficiently than the traditional FC method.

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

Directory of Open Access Journals (Sweden)

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

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

Science.gov (United States)

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

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 without

Risks and recommendations to perform flexible bronchoscopy in pregnant woman

International Nuclear Information System (INIS)

Majid, Adnan; Ernst, Armin; Begolli, Melissa; Canas, Alejandra

2008-01-01

If possible, it is advisable to postpone Flexible Bronchoscopy until after delivery, or at least until after the twenty eighth week of pregnancy. Bronchoscopy should be carried out by the most experienced pulmonologist and in a hospital facility where anesthesiology, obstetrics and neonatology departments are available. Consultation with these specialists is recommended. A pharmacologist should be consulted with regard to the teratogenic potential of the drugs that are to be used during bronchoscopy. The lowest possible doses of drugs should be used for sedation, and drugs of the D and X categories should not be used. During the procedure, it is advisable to carry out continual monitoring of cardiac rhythm and pulse oximetry, as well as intermittent measurements of arterial blood pressure. If possible, fetal monitoring should be carried out. The patient should be placed in the left lateral decubitus position. If this is not possible, the procedure should be carried out with the patient in the sitting position. The duration of the procedure should be minimized, and it should be terminated if the patient does not tolerate it well. The convenience of using fluoroscopy has to be considered separately in each case, taking into consideration its potential risks and benefits. Technological advances for the diagnosis and treatment of pulmonary and airway diseases, such as endobronchial ultrasound, CT scanning with fluoroscopy and bronchoscopy

[Virtual CT-pneumocystoscopy: indications, advantages and limitations. Our experience].

Science.gov (United States)

Regine, Giovanni; Atzori, Maurizio; Buffa, Vitaliano; Miele, Vittorio; Ialongo, Pasquale; Adami, Loredana

2003-09-01

The use of CT volume-rendering techniques allows the evaluation of visceral organs without the need for endoscopy. Conventional endoscopic evaluation of the bladder is limited by the invasiveness of the technique and the difficulty exploring the entire bladder. Virtual evaluation of the bladder by three-dimensional CT reconstruction offers potential advantages and can be used in place of endoscopy. This study investigates the sensitivity of virtual CT in assessing lesion of the bladder wall to compare it with that of conventional endoscopy, and outlines the indications, advantages and disadvantages of virtual CT-pneumocystography. Between September 2001 and May 2002, 21 patients with haematuria and positive cystoscopic findings were studied. After an initial assessment by ultrasound, the patients underwent pelvic CT as a single volumetric scan after preliminary air distension of the bladder by means of 12 F Foley catheter. The images were processed on an independent workstation (Advantage 3.0 GE) running dedicated software for endoluminal navigation. The lesions detected by endoscopy were classified as sessile or pedunculated, and according to size (more or less than 5 mm). Finally, the results obtained at virtual cystoscopy were evaluated by two radiologists blinded to the conventional cystoscopy results. Thirty lesions (24 pedunculated, 6 sessile) were detected at conventional cystoscopy in 16 patients (multiple polyposis in 3 cases). Virtual cystoscopy identified 23 lesions (19 pedunculated and 4 sessile). The undetected lesions were pedunculated <5 mm (5 cases) and sessile (2 cases). One correctly identified pedunculated lesion was associated with a bladder stone. Good quality virtual images were obtained in all of the patients. In only one patient with multiple polyposis the quality of the virtual endoscopic evaluation was limited by the patient's intolerance to bladder distension, although identification of the lesions was not compromised. The overall

Using Performance in Multiple Simulated Scenarios to Assess Bronchoscopy Skills

DEFF Research Database (Denmark)

Konge, Lars; Arendrup, Henrik; Buchwald, Christian von

2011-01-01

using a standardized scoring form. Methods: The test was administered on a virtual reality bronchoscopy simulator to a total of 42 test subjects (14 senior consultants, 14 trainees and 14 medical students). The inter-rater reliability of the test procedure was explored according to examination of test......Background: International guidelines suggest that trainees should perform at least 100 flexible bronchoscopies in a supervised setting, but this number is not evidence based. An objective assessment method could provide educational feedback to trainees and help supervisors decide when basic...... competency is established. No former assessment instrument has been able to distinguish between trainees and experts. Objectives: The aim of this study was to explore the validity and reliability of a new assessment procedure relating to testing operators across multiple tasks with increasing difficulty...

Anaesthesia for bronchoscopy

Directory of Open Access Journals (Sweden)

Meenu Chadha

2015-01-01

Full Text Available Bronchoscopy as an investigation or therapeutic procedure demands anaesthesiologist to act accordingly. The present review will take the reader from rigid to fibreoptic flexible bronchoscopy. These procedures are now done as day care procedures in the operation theatre or in critical care units. Advantages and limitations of both rigid and flexible bronchoscopy are analysed. Recently, conscious sedation has come up as the commonly used anaesthetic technique for simple bronchoscopic procedures. However, general anaesthesia still remains a standard technique for more complex procedures. New advances in the field of anaesthesiology such as use of short acting opioids, use of newer drugs such as dexmedetomidine, supraglottic airways and mechanical jet ventilators have facilitated and eased the conduct of the procedure.

Spiral CT biliary virtual endoscopy: preliminary clinical applications in the detection of biliary calculus

International Nuclear Information System (INIS)

Xiong Minghui; Wang Dong; Song Yunlong; Zhang Wanshi; Xu Jiaxing

2000-01-01

Objective: To evaluate imaging features and clinical value of CT biliary virtual endoscopy in the detection of biliary calculus. Methods: Eighteen patients with biliary calculi underwent volume scanning using spiral CT (Hispeed Advantage CT/i GE ). All data were transferred to computer workstation, and CT biliary virtual endoscopy images with pseudocolor encoding were generated from the volumetric data using the Navigator Smooth soft-ware. All cases were proved by ultrasound, axial CT or operation. Results: Among 18 cases, gallstones were found 8 in cases, common bile duct stones in 2 cases, gallstones and bile duct stones in 6 cases. The stones were 0.3-3.2 cm in size. CT biliary virtual endoscopy correctly demonstrated the surface details of stones which were viewed from extra- or intraluminal orientation in a 3D fashion. The findings were consistent with those of US, CT or operation. Conclusion: The CT virtual biliary endoscopy is a further development of virtual endoscopy for observing biliary calculus from intra- and extra-luminal views and providing three dimensional information of stone

Uso da broncoscopia virtual em pacientes pediátricos com suspeita de aspiração de corpo estranho Use of virtual bronchoscopy in children with suspected foreign body aspiration

Directory of Open Access Journals (Sweden)

Tiago Neves Veras

2009-09-01

Full Text Available A aspiração de corpo estranho (ACE para o trato respiratório é um problema comum em pacientes pediátricos, em especial abaixo dos três anos de idade. Na avaliação radiológica inicial, cerca de 30% dos pacientes apresentam radiograma de tórax normal. A tomografia com broncoscopia virtual (BV pode auxiliar no diagnóstico precoce desse quadro e seu pronto manejo. O tratamento definitivo se dá com a retirada do corpo estranho através de broncoscopia rígida e mediante anestesia geral. O objetivo deste trabalho foi descrever o uso da BV na abordagem de dois pacientes com suspeita de ACE e realizar uma revisão da literatura sobre este tópico. Os dois pacientes tiveram início súbito de sintomas respiratórios e relato de tosse ou engasgo com alimentos antecedendo o quadro. Os pacientes foram submetidos à BV, e foi detectada a presença de corpo estranho endobrônquico em ambos os casos, com remoção posterior por broncoscopia rígida convencional em um caso. A BV é um método não-invasivo recente e com potencial para detectar a presença de corpo estranho na via respiratória em crianças. Em casos selecionados, BV pode auxiliar na localização correta do corpo estranho e até mesmo evitar o procedimento de broncoscopia rígida na ausência de corpo estranho.Foreign body aspiration (FBA into the tracheobronchial tree is a common problem in children, especially in those under three years of age. Preliminary radiological evaluation reveals normal chest X-rays in nearly 30% of such patients. Tomography-generated virtual bronchoscopy (VB can facilitate the early diagnosis and rapid management of these cases. The definitive treatment is the removal of the foreign body by means of rigid bronchoscopy under general anesthesia. The objective of this study was to describe the use of VB in two patients with suspicion of FBA, as well as to review the literature regarding this topic. The two patients presented with sudden onset of respiratory

Interventionist Bronchoscopy

International Nuclear Information System (INIS)

Pineyro Gutierrez, L.M.

1997-01-01

Interventional bronchoscopy includes endoscopic diagnostic procedures through rigid bronchoscope, such as transcarinal puncture and principally, therapeutic bronchoscopy using lasers tends and endoscopic radiation. This is a review of our experience in this field, analyzing 36 transcarinal punctures with goods results in 10 cases (27%), 100 patients for whom it used laser in tracheobronchial disorders with satisfactory results in 81,5% and the placement of 8 Dumon's tends with different results, according to the tracheal pathology. The management of tracheal benign stenosis is controversial. It has had good results in 56,5% over 23 patients for whom we used endoscopic management [es

Virtual endoscopy post-processing of helical CT data sets

International Nuclear Information System (INIS)

Dessl, A.; Giacomuzzi, S.M.; Springer, P.; Stoeger, A.; Pototschnig, C.; Voelklein, C.; Schreder, S.G.; Jaschke, W.

1997-01-01

Purpose: The purpose of this work was to test a newly developed, post-processing software for virtual CT endoscopic methods. Virtual endoscopic images were generated from helical CT data sets in the region of the shoulder joint (n=2), the tracheobronchial system (n=3), the nasal sinuses (n=2), the colon (n=2), and the common carotid artery (n=1). Software developed specifically for virtual endoscopy ('Navigator') was used which, after a previous threshold value selection, makes the reconstruction of internal body surfaces possible by an automatic segmentation process. We have evaluated the usage of the software, the reconstruction time for individual images and sequences of images as well as the quality of the reconstruction. All pathological findings of the virtual endoscopy were confirmed by surgery. Results: The post-processing program is easy to use and provides virtual endoscopic images within 50 seconds. Depending of the extent of the data set, virtual tracheobronchoscopy as a cine loop sequence required about 15 minutes. Thorugh use of the threshold value-dependent surface reconstruction the demands on the computer configuration are limited; however, this also created quality problems in image calculation as a consequence of the accompanying loss of data. Conclusions: The Navigator software enables the calculation of virtual endoscopic models with only moderate demands on the hardware. (orig.) [de

Endobronchial metastasis: CT findings and its usefulness in bronchoscopic correlation

International Nuclear Information System (INIS)

Ko, Ji Ho; Jung, Gyoo Sik; Kim, Seong Min; Huh Jin Do; Joh, Young Duk; Jang, Tae Weon

2000-01-01

To evaluate the CT findings of bronchial abnormalities in patients with endobronchial metastasis from extrapulmonary tumors, and to correlate these with the bronchoscopic findings. The authors retrospectively reviewed the CT and bronchoscopic findings of 17 patients (M:F =3D 9:8; mean age, 56 years) with histologically proven endobronchial metastasis from extrapulmonary primary tumors. Carcinoma of the uterine cervix (n=3D5) was the most common primary site for endobronchial metastasis. CT findings of bronchial abnormalities with associated peribronchial and lung parenchymal lesions were analyzed and compared with the bronchoscopic findings. Among the 17 patients, 20 sites of bronchial abnormalities were visualized bronchoscopically. CT findings of bronchial abnormalities were smooth narrowing (n=3D11), occlusion (n=3D3), intraluminal mass (n=3D4), and normal (n=3D2). Peribronchial lesions (lymph node enlargement or parenchymal mass) were found in 12 cases. Bronchoscopy revealed bronchial narrowing due to a mucosal nodule or intraluminal polypoid mass in 16 cases, and total obstruction of the bronchus in four. With regard to the identification of bronchial abnormalities, the findings of CT and of bronchoscopy agreed in 17 cases and disagreed in three. While bronchoscopy was advantageous for detecting early mucosal abnormality, CT effectively evaluated the extent of a lesion beyond the stenosis or bronchial obstruction. CT was also useful for predicting the causes of bronchial abnormalities. CT is relatively accurate in evaluating bronchial abnormalities, and in patients with endobronchial metastases may be used as a complementary procedure to bronchoscopy for evaluating the extent of the lesion. (author)

Simulation in bronchoscopy

DEFF Research Database (Denmark)

Nilsson, Philip Mørkeberg; Naur, Therese Maria Henriette; Clementsen, Paul Frost

2017-01-01

, and the training should be structured as distributed practice with mastery learning criteria (ie, training until a certain level of competence is achieved). Dyad practice (training in pairs) is possible and may increase utility of available simulators. Trainee performance should be assessed with assessment tools......Objective: To provide an overview of current literature that informs how to approach simulation practice of bronchoscopy and discuss how findings from other simulation research can help inform the use of simulation in bronchoscopy training. Summary: We conducted a literature search on simulation...

New frontiers in CT imaging of airway disease

International Nuclear Information System (INIS)

Grenier, Philippe A.; Beigelman-Aubry, Catherine; Fetita, Catalin; Preteux, Francoise; Brauner, Michel W.; Lenoir, Stephane

2002-01-01

Combining helical volumetric CT acquisition and thin-slice thickness during breath hold provides an accurate assessment of both focal and diffuse airway diseases. With multiple detector rows, compared with single-slice helical CT, multislice CT can cover a greater volume, during a simple breath hold, and with better longitudinal and in-plane spatial resolution and improved temporal resolution. The result in data set allows the generation of superior multiplanar and 3D images of the airways, including those obtained from techniques developed specifically for airway imaging, such as virtual bronchography and virtual bronchoscopy. Complementary CT evaluation at suspended or continuous full expiration is mandatory to detect air trapping that is a key finding for depicting an obstruction on the small airways. Indications for CT evaluation of the airways include: (a) detection of endobronchial lesions in patients with an unexplained hemoptysis; (b) evaluation of extent of tracheobronchial stenosis for planning treatment and follow-up; (c) detection of congenital airway anomalies revealed by hemoptysis or recurrent infection; (d) detection of postinfectious or postoperative airway fistula or dehiscence; and (e) diagnosis and assessment of extent of bronchiectasis and small airway disease. Improvement in image analysis technique and the use of spirometrically control of lung volume acquisition have made possible accurate and reproducible quantitative assessment of airway wall and lumen areas and lung density. This contributes to better insights in physiopathology of obstructive lung disease, particularly in chronic obstructive pulmonary disease and asthma. (orig.)

Image fusion in craniofacial virtual reality modeling based on CT and 3dMD photogrammetry.

Science.gov (United States)

Xin, Pengfei; Yu, Hongbo; Cheng, Huanchong; Shen, Shunyao; Shen, Steve G F

2013-09-01

The aim of this study was to demonstrate the feasibility of building a craniofacial virtual reality model by image fusion of 3-dimensional (3D) CT models and 3 dMD stereophotogrammetric facial surface. A CT scan and stereophotography were performed. The 3D CT models were reconstructed by Materialise Mimics software, and the stereophotogrammetric facial surface was reconstructed by 3 dMD patient software. All 3D CT models were exported as Stereo Lithography file format, and the 3 dMD model was exported as Virtual Reality Modeling Language file format. Image registration and fusion were performed in Mimics software. Genetic algorithm was used for precise image fusion alignment with minimum error. The 3D CT models and the 3 dMD stereophotogrammetric facial surface were finally merged into a single file and displayed using Deep Exploration software. Errors between the CT soft tissue model and 3 dMD facial surface were also analyzed. Virtual model based on CT-3 dMD image fusion clearly showed the photorealistic face and bone structures. Image registration errors in virtual face are mainly located in bilateral cheeks and eyeballs, and the errors are more than 1.5 mm. However, the image fusion of whole point cloud sets of CT and 3 dMD is acceptable with a minimum error that is less than 1 mm. The ease of use and high reliability of CT-3 dMD image fusion allows the 3D virtual head to be an accurate, realistic, and widespread tool, and has a great benefit to virtual face model.

On proton CT reconstruction using MVCT-converted virtual proton projections

Energy Technology Data Exchange (ETDEWEB)

Wang Dongxu; Mackie, T. Rockwell; Tome, Wolfgang A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Morgridge Institute of Research, University of Wisconsin, Madison, Wisconsin 53715 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Oncophysics Institute, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461 (United States)

2012-06-15

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of {+-}0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of {+-}0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of {+-}1.1% compared with that reconstructed from theoretical projections

On proton CT reconstruction using MVCT-converted virtual proton projections

International Nuclear Information System (INIS)

Wang Dongxu; Mackie, T. Rockwell; Tomé, Wolfgang A.

2012-01-01

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of ±0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of ±0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of ±1.1% compared with that reconstructed from theoretical projections. If

Virtual Non-Contrast CT Using Dual-Energy Spectral CT: Feasibility of Coronary Artery Calcium Scoring

OpenAIRE

Song, Inyoung; Yi, Jeong Geun; Park, Jeong Hee; Kim, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

Objective 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. Materials and Methods 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 V...

Virtual reality simulation of basic pulmonary procedures

DEFF Research Database (Denmark)

Konge, Lars; Arendrup, Henrik; von Buchwald, Christian

2011-01-01

Background: Virtual reality (VR) bronchoscopy simulators have been available for more than a decade, and have been recognized as an important aid in bronchoscopy training. The existing literature has only examined the role of VR simulators in diagnostic bronchoscopy. The aim of this study......, the physicians answered a questionnaire regarding the realism of the simulator. Results: The realism of the anatomy and the appearance of the scope were rated higher than the movement of the scope, feeling of resistance, and performances of bronchoalveolar lavages and biopsies. Overall, the simulator was judged...

Effects of bronchoscopy on lung function in asthmatics.

Science.gov (United States)

Bellinger, Christina; Bleecker, Eugene R; Peters, Stephen; Pascual, Rodolfo; Krings, Jeffrey; Smith, Regina; Hastie, Annette T; Moore, Wendy C

2017-10-01

To better understand the changes in pulmonary physiology related to asthma severity following bronchoscopy, we performed scheduled pre- and post-procedure spirometry on subjects undergoing bronchoscopy in our research program. Control subjects and asthma subjects were recruited for bronchoscopy. On the day of bronchoscopy, subjects underwent spirometry pre-bronchoscopy and then up to three sets within 2 hour following the completion of bronchoscopy. A subset of patients had a second bronchoscopy after 2 weeks of treatment with oral prednisolone (40mg daily). A total of 92 subjects had at least one bronchoscopy (12 control subjects, 56 nonsevere asthma (NSA), 24 severe asthma (SA)). The SA and NSA groups had similar decreases in forced expiratory volume in 1 second (FEV1) (-20±13% vs.-19±16%, p = 0.92) and forced vital capacity (FVC) (-20±12% vs.-20±14%, p = 0.80), but no change in FEV1/FVC ratio. The control and NSA group had more rapid recovery of both FEV1 and FVC by 2 hour compared to the SA group (p = 0.01). In the subset of 36 subjects (22 NSA, 14 SA) who underwent a second bronchoscopy following the administration of oral prednisolone for 14 days, steroids resulted in more rapid recovery of lung function (p NSA subjects recovered more quickly than SA subjects. Treatment with oral corticosteroids was associated with a quicker recovery of FEV1 which suggests an inflammatory mechanism for these changes in lung compliance.

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

International Nuclear Information System (INIS)

Ingram, W; Rao, A; Wendt, R; Court, L; Yang, J; Beadle, B

2015-01-01

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

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

Treatment response assessment of radiofrequency ablation for hepatocellular carcinoma: Usefulness of virtual CT sonography with magnetic navigation

International Nuclear Information System (INIS)

Minami, Yasunori; Kitai, Satoshi; Kudo, Masatoshi

2012-01-01

Purpose: Virtual CT sonography using magnetic navigation provides cross sectional images of CT volume data corresponding to the angle of the transducer in the magnetic field in real-time. The purpose of this study was to clarify the value of this virtual CT sonography for treatment response of radiofrequency ablation for hepatocellular carcinoma. Patients and methods: Sixty-one patients with 88 HCCs measuring 0.5–1.3 cm (mean ± SD, 1.0 ± 0.3 cm) were treated by radiofrequency ablation. For early treatment response, dynamic CT was performed 1–5 days (median, 2 days). We compared early treatment response between axial CT images and multi-angle CT images using virtual CT sonography. Results: Residual tumor stains on axial CT images and multi-angle CT images were detected in 11.4% (10/88) and 13.6% (12/88) after the first session of RFA, respectively (P = 0.65). Two patients were diagnosed as showing hyperemia enhancement after the initial radiofrequency ablation on axial CT images and showed local tumor progression shortly because of unnoticed residual tumors. Only virtual CT sonography with magnetic navigation retrospectively showed the residual tumor as circular enhancement. In safety margin analysis, 10 patients were excluded because of residual tumors. The safety margin more than 5 mm by virtual CT sonographic images and transverse CT images were determined in 71.8% (56/78) and 82.1% (64/78), respectively (P = 0.13). The safety margin should be overestimated on axial CT images in 8 nodules. Conclusion: Virtual CT sonography with magnetic navigation was useful in evaluating the treatment response of radiofrequency ablation therapy for hepatocellular carcinoma.

Flexible fiberoptic bronchoscopy in respiratory care: Diagnostic yield ...

African Journals Online (AJOL)

Introduction: Flexible fiberoptic bronchoscopy (FOB) is a key diagnostic and therapeutic procedure in pulmonology. Experience with fiberoptic bronchoscopy is scanty in most developing countries. Objectives: The goal of this study was to report our experience and clinical utility of fiberoptic bronchoscopy. Methods: A review ...

The feasibility of surgical site tagging with CT virtual reality of the paranasal sinuses.

Science.gov (United States)

Hopper, K D; Iyriboz, A T; Wise, S W; Fornadley, J A

1999-01-01

The purpose of this work was to evaluate the feasibility of tagging (highlighting) surgical sites using volumetric CT virtual reality of the paranasal sinuses in the planning for endoscopic sinus surgery. Twenty-five patients with significant paranasal sinus disease had a planned surgical site marked on 2D coronal images. This planned surgical site was then tagged and included on CT volumetric virtual reality imaging. Each case was evaluated as to the ability of the CT virtual reality to demonstrate the planned surgical site and its orientation with respect to adjacent superficial anatomy. For all 25 planned surgeries, the virtual images showed the entire surgical site marked on the 2D coronal images. In all 25 cases, the orientation of the planned surgical site to adjacent normal anatomy was well demonstrated. For surgery into the maxillary sinuses, tagging and electronic removal of the middle turbinates and uncinate processes mimicked the actual surgery and allowed complete visualization of the infundibulum and the planned surgical site. Planned endoscopic paranasal sinus surgical sites can be easily and reliably highlighted using CT virtual reality techniques with respect to the patient's normal endoscopic anatomy.

Airway segmentation and centerline extraction from thoracic CT : Comparison of a new method to state of the art commercialized methods

NARCIS (Netherlands)

Reynisson, P.J.; Scali, M.; Smistad, E.; Hofstad, E.F.; Leira, H.O.; Lindseth, F.; Nagelhus Hernes, T.A.; Amundsen, T.; Sorger, H.; Lango, T.

2015-01-01

Our motivation is increased bronchoscopic diagnostic yield and optimized preparation, for navigated bronchoscopy. In navigated bronchoscopy, virtual 3D airway visualization is often used to guide a bronchoscopic tool to peripheral lesions, synchronized with the real time video bronchoscopy.

Flexible fiberoptic bronchoscopy service; an aid to patient management

LENUS (Irish Health Repository)

Marathe, N

2016-02-01

The study illustrates advantages of Fiberoptic Bronchoscopy, a new service started at St. Luke’s General Hospital in patient care since April 2014. Retrospective review of Bronchoscopies and referrals to Tertiary care unit for Bronchoscopy, prior and after initiation of service at St. Luke’s Hospital were studied. In total, 106 procedures were performed out of which 103(98%) were for diagnostic purpose. Common indications for bronchoscopy were functional airway assessment in 38 cases (35%) of chronic cough, 26 cases (24.8%) of suspected malignancy. The average time taken for procedure was 15 + 1 minute with overall rate of complication recorded in 1 case (0.95%). 32(30%) inpatients were referred before bronchoscopy services were started locally. Fifteen (14%) patients were referred for Endobronchial Ultrasound (EBUS) after diagnostic procedure performed at St. Luke’s Hospital. To conclude, Bronchoscopy is a safe procedure used for diagnosis of various Lung conditions. The services offered locally reduced the time and cost involved in referrals. The diagnostic bronchoscopies performed for malignancy at St. Luke’s Hospital have rightly increased references for EBUS at Tertiary care Unit

Virtual non-contrast of liver from dual energy CT: a clinical application

International Nuclear Information System (INIS)

Qian Yu'e; Hu Hongjie; Zhang Qiaowei; Hu Peng; Shen Guohui

2011-01-01

Objective: To assess the virtual non-contrast liver CT from dual-energy CT for the clinical application. Methods: In total, 51 patients were included in the study, and all patients underwent multi-phase liver CT on a dual-source CT. The True non-contrast liver CT (TNCT) was performed in a single-energy acquisition mode, but the arterial and portovenous liver CT (VNCT) were performed in a dual- energy mode of 110 kV and 140 kV respectively. The virtual non-contrast CT images were derived from the arterial data using liver virtual non-contrast software. Between the true non-contrast CT and the virtual non- contrast CT, the image quality, mean CT HU values in the liver and muscle, signal to noise (SNR), the radiation dose of volume CT dose index (CTDIvol) and dose length product (DLP) in a single phase and total examination were compared with t test. Results: There was no significant difference in the detection of' liver lesions between TNCT and VNCT. The CT Hu values of muscle on both TNCT and VNCT images were almost equal. The CT HU values of liver on VNCT images were higher than that on TNCT images and the difference was significant [61.32±6.04 vs. (56.85±4.80) HU, t=-3.927, P<0.01]. There was also significant difference of SNR between TNCT (11.28±2.78) and VNCT (8.65±1.56) images (t=-5.590, P<0.01). The CTDIvol and DLP of single phase were (7.07±0.85) mGy and (155.11± 22.52) mGy · cm respectively in TNCT, and (7.05±0.87) mGy and (154.48±23.12) mGy · cm in VNCT. The total CTDIvol and DLP in VNCT were (14.35±1.66) mGy and (313.91±45.08) mGy · cm respectively, but in TNCT the total CTDIvol and DLP reached (21.43±2.46) mGy and (469.02± 66.22) mGy · cm. The difference of CTDIvol and DLP in single phase between TNCT and VNCT showed no significance, but the total CTDIvol and DLP were significantly different (t=16.168 and 13.132, P< 0.01). Conclusion: With the consequent reduction in radiation dose, the VNCT can replace TNCT as an imaging protocol in multi

Virtual endoscopy using spiral CT in patients with carcinomas of the hypopharynx and larynx

International Nuclear Information System (INIS)

Song, Sang Gook; Seo, Jeong Jin; Chung, Tae Woong; Kim, Hyeong Kil; Jeong, Gwang Woo; Jeong, Yong Yeon; Kang, Heoung Keun; Cho, Jae Sik

2000-01-01

To compare the usefulness of virtual endoscopy using spiral CT with that of laryngoscopy in the detection and evaluation of laryngeal and pharyngeal carcinomas. Twenty-four patients with pathologically proven laryngeal and pharyngeal carcinomas underwent laryngoscopy and virtual endoscopy using spiral CT. Eleven of the carcinomas were supraglottic, five were glottic, and eight were hypopharyngeal. Source images obtained by spiral CT were transmitted to an independent workstation and virtual endoscopic images were obtained using Navigator software. These were graded according to their quality (good, fair, bad), and were interpreted by two radiologists who were blinded to the conventional endoscopic findings. These latter were subsequently compared with the virtual endoscopic findings in terms of similarity to laryngoscopic examination and detectability of lesions. The overall image quality of virtual endoscopy was good in 16 cases (67%), fair in eight (33%), and bad in no case. Among the 11 supraglottic carcinomas, image quality was good in seven cases (64%), and fair in four (36%). In four of the five glottic carcinomas (80%) quality was good, and in one case (20%) it was fair, while among the eight hypopharyngeal carcinomas, quality was good in five cases (63%), and fair in three (37%). Overall, detection of the lesion was possible in 23 cases (96%). Due to the small size of the lesion, the one case of glottic carcinoma was not detected. Virtual endoscopy using spiral CT is a safe and noninvasive method, and also successfully detects laryngeal and pharyngeal lesions, with good image quality. For the evaluation of laryngeal and hypopharyngeal carcinoma, its use ma complement that of axial CT. (author)

Algorithm for Video Summarization of Bronchoscopy Procedures

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Leszczuk Mikołaj I

2011-12-01

Full Text Available Abstract Background The duration of bronchoscopy examinations varies considerably depending on the diagnostic and therapeutic procedures used. It can last more than 20 minutes if a complex diagnostic work-up is included. With wide access to videobronchoscopy, the whole procedure can be recorded as a video sequence. Common practice relies on an active attitude of the bronchoscopist who initiates the recording process and usually chooses to archive only selected views and sequences. However, it may be important to record the full bronchoscopy procedure as documentation when liability issues are at stake. Furthermore, an automatic recording of the whole procedure enables the bronchoscopist to focus solely on the performed procedures. Video recordings registered during bronchoscopies include a considerable number of frames of poor quality due to blurry or unfocused images. It seems that such frames are unavoidable due to the relatively tight endobronchial space, rapid movements of the respiratory tract due to breathing or coughing, and secretions which occur commonly in the bronchi, especially in patients suffering from pulmonary disorders. Methods The use of recorded bronchoscopy video sequences for diagnostic, reference and educational purposes could be considerably extended with efficient, flexible summarization algorithms. Thus, the authors developed a prototype system to create shortcuts (called summaries or abstracts of bronchoscopy video recordings. Such a system, based on models described in previously published papers, employs image analysis methods to exclude frames or sequences of limited diagnostic or education value. Results The algorithm for the selection or exclusion of specific frames or shots from video sequences recorded during bronchoscopy procedures is based on several criteria, including automatic detection of "non-informative", frames showing the branching of the airways and frames including pathological lesions. Conclusions

Patient-specific bronchoscopy visualization through BRDF estimation and disocclusion correction.

Science.gov (United States)

Chung, Adrian J; Deligianni, Fani; Shah, Pallav; Wells, Athol; Yang, Guang-Zhong

2006-04-01

This paper presents an image-based method for virtual bronchoscope with photo-realistic rendering. The technique is based on recovering bidirectional reflectance distribution function (BRDF) parameters in an environment where the choice of viewing positions, directions, and illumination conditions are restricted. Video images of bronchoscopy examinations are combined with patient-specific three-dimensional (3-D) computed tomography data through two-dimensional (2-D)/3-D registration and shading model parameters are then recovered by exploiting the restricted lighting configurations imposed by the bronchoscope. With the proposed technique, the recovered BRDF is used to predict the expected shading intensity, allowing a texture map independent of lighting conditions to be extracted from each video frame. To correct for disocclusion artefacts, statistical texture synthesis was used to recreate the missing areas. New views not present in the original bronchoscopy video are rendered by evaluating the BRDF with different viewing and illumination parameters. This allows free navigation of the acquired 3-D model with enhanced photo-realism. To assess the practical value of the proposed technique, a detailed visual scoring that involves both real and rendered bronchoscope images is conducted.

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

International Nuclear Information System (INIS)

Rieger, Michael; Gruber, Hannes; Jaschke, Werner R.; Gabl, Markus; Mallouhi, Ammar

2005-01-01

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.)

Flexible bronchoscopy and mechanical ventilation in managing Mounier-Kuhn syndrome: a case report

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Aslihan Gürün Kaya

2017-04-01

Full Text Available ABSTRACT CONTEXT: Mounier-Kuhn syndrome is a rare congenital condition with distinct dilatation and diverticulation of the tracheal wall. The symptoms may vary and the treatment usually consists of support. CASE REPORT: The patient was a 60-year-old male with recurrent hospital admission. He was admitted in this case due to dyspnea, cough and sputum production. An arterial blood sample revealed decompensated respiratory acidosis with moderate hypoxemia. A chest computed tomography (CT scan showed dilatation of the trachea and bronchi, tracheal diverticula and bronchiectasis. Flexible bronchoscopy was performed, which revealed enlarged airways with expiratory collapse. Furthermore, orifices of tracheal diverticulosis were also detected. Non-invasive positive pressure ventilation (NPPV was added, along with long-term oxygen therapy. At control visits, the patient’s clinical and laboratory findings were found to have improved. CONCLUSION: Flexible bronchoscopy can be advocated for establishing the diagnosis and non-invasive mechanical ventilation can be used with a high success rate, for clinical wellbeing in Mounier-Kuhn syndrome.

Therapeutic flexible bronchoscopy in child with cystic fibrosis

Directory of Open Access Journals (Sweden)

Amina Selimović

2008-05-01

Full Text Available The report deals with the case of a 10-year-old girl with chronic cystic fibrosis. She has been repeatedly treated at the hospital. She has been hospitalized due to respiratory deterioration. Cystic fibrosis is a rare disease, inherited autosomaly recessively, but is very complex in terms of diagnostic and treatment (2. The diagnosis is confirmed based on a clinical picture of the child, measure of Chloride in the sweat, chest X-ray, CT thorax, laboratory findings--genetic confirmation CFTR ( cystic fibrosis transmembrane conductance regulator genes (3, which result in the production of hyper-viscous mucus and chloride malabsorption in the sweat glands ducts (5,6. Bronchial thickening and plugging and ring shadows suggesting bronchiectasis, segmental or lobar atelectasis are often. Computer tomography of the chest can be used to detect and localize thickening of bronchial airways walls, mucus plugging, hyperinflation and early bronchieactasiae. Pulmonary therapy: the object is to clear secretions from airways and to control infection (7. The diagnosis is originally set when she was 4 years old. She is now admitted due to a deterioration of the main disease. Day before admission in the hospital had a higher bodily temperature, cough and difficult breathing. She already treated conservatively (Ceftazidim, Ceftriakson, Kloksacillin Since the girl is a chronic patient with bronchiectasie chronic walls of bronchi changes full of the mucus, who is not responding to conservative treatment (antibiotics, therapeutic and diagnostic flexible bronchoscopy had to be performed, resulting in a gram-negative bacteria pseudomonas aeruginosa--a typical bacteria for chronically sick C. F.PATIENT:A pseudomonas therapy was prescribed according to the sensitive antibiogram, during which bronchoscopy was given locally on changes mucous pulmozyme and garamycin. Flexible bronchoscopy was performed as therapeutic. Local bronchoscopy

Helical CT in evaluation of the bronchial tree

International Nuclear Information System (INIS)

Perhomaa, M.; Laehde, S.; Rossi, O.; Suramo, I.

1997-01-01

Purpose: To establish a protocol for and to assess the value of helical CT in the imaging of the bronchial tree. Material and Methods: Noncontrast helical CT was performed in 30 patients undergoing fiberoptic bronchoscopy for different reasons. Different protocols were compared; they included overlapping 10 mm, 5 mm, or 3 mm slices and non-tilted, cephalad or caudal tilted images. Ordinary cross-sectional and multiplanar 2D reformats were applied for visualization of the bronchial branches. The effect of increasing the helical pitch was tested in one patient. Results: A total of 92.1-100% of the segmental bronchi present in the helical acquisitions were identified by the different protocols. The collimation had no significant impact on the identification of the bronchial branches, but utilization of 3-mm overlapping slices made it easier to distinguish the nearby branches and provided better longitudinal visualization of the bronchi in 2D reformats. The tilted scans illustrated the disadvantage of not covering all segmental bronchi in one breath-hold. An increase of the pitch from 1 to 1.5 did not cause noticeable blurring of the images. CT and bronchoscopic findings correlated well in the area accessible to bronchoscopy, but CT detected 5 additional pathological lesions (including 2 cancers) in the peripheral lung. Conclusion: Helical CT supplemented with bronchography-like 2D reformats provides an effective method complementary to bronchoscopy in the examination of the bronchial tree. (orig.)

Diagnosis value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma

International Nuclear Information System (INIS)

Ma Zhoupeng; Zhou Jianjun; Liu Xueling; Wang Chun; Zhang Shunzhuang

2012-01-01

Objective: To explore the diagnostic value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma. Methods: Sixty patients who were suspected of clear cell renal cell carcinoma underwent non-enhanced CT and contrast enhancement CT of early interface-phase between cortex -medulla and parenchymal phase on a dual-energy CT. The true non-enhanced kidney CT (TNCT) was performed in a single-energy acquisition mode, but the dual-phase contrast enhancement CT were performed in a dual-energy mode of 80 kV and 140 kV respectively. The virtual non-enhanced CT (VNCT) images were derived from the data of early interface phase using liver virtual non-contrast software. The diagnose according to VNCT combined dual-phase contrast enhancement CT and dual-phase contrast enhancement CT only were made respectively and compared with χ 2 test. Between the true non-contrast CT and the virtual non-contrast CT, the image quality was compared with Wilcoxon test; The radiation dose of volume CT dose index (CTDIvol) and dose length product(DLP) in a single-phase and total examination, the mean CT HU values of the tumours were compared with t test. Results: The accuracy of VNCT combined dual-phase contrast enhancement CT was higher than that of dual-phase contrast enhancement CT only [93.3% (56/60) vs.78.3% (47/60); χ 2 =5.6, P<0.05]. The detective ability (score) of VNCT was near to that of TNCT and the difference was not obvious (Z=0.00, P>0.05). The radiation dose of volume CT dose index (CTDIvol) and dose length product (DLP) in a single phase and total examination of VNCT [(8.85 ± 1.28) mGy, (196.45 ±21.12) mGy·cm, (17.69±2.35) mGy, (392.90±42.25) mGy · cm] were lower than that of TNCT [(10.20 ± 1.44) mGy,(218.29 ± 29.60) mGy · cm, (30.61 ± 3.27) mGy and (654.86 ± 88.81) mGy ·cm], t=4.21, 3.58, 23.63, 16.12 respectively, P<0.05. The mean CT HU values of tumours on VNCT images was higher than that

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.

Technical Note: Improved CT number stability across patient size using dual-energy CT virtual monoenergetic imaging

International Nuclear Information System (INIS)

Michalak, Gregory; Grimes, Joshua; Fletcher, Joel; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia; Halaweish, Ahmed

2016-01-01

Purpose: The purpose of this study was to evaluate, over a wide range of phantom sizes, CT number stability achieved using two techniques for generating dual-energy computed tomography (DECT) virtual monoenergetic images. Methods: Water phantoms ranging in lateral diameter from 15 to 50 cm and containing a CT number test object were scanned on a DSCT scanner using both single-energy (SE) and dual-energy (DE) techniques. The SE tube potentials were 70, 80, 90, 100, 110, 120, 130, 140, and 150 kV; the DE tube potential pairs were 80/140, 70/150Sn, 80/150Sn, 90/150Sn, and 100/150Sn kV (Sn denotes that the 150 kV beam was filtered with a 0.6 mm tin filter). Virtual monoenergetic images at energies ranging from 40 to 140 keV were produced from the DECT data using two algorithms, monoenergetic (mono) and monoenergetic plus (mono+). Particularly in large phantoms, water CT number errors and/or artifacts were observed; thus, datasets with water CT numbers outside ±10 HU or with noticeable artifacts were excluded from the study. CT numbers were measured to determine CT number stability across all phantom sizes. Results: Data exclusions were generally limited to cases when a SE or DE technique with a tube potential of less than 90 kV was used to scan a phantom larger than 30 cm. The 90/150Sn DE technique provided the most accurate water background over the large range of phantom sizes evaluated. Mono and mono+ provided equally improved CT number stability as a function of phantom size compared to SE; the average deviation in CT number was only 1.4% using 40 keV and 1.8% using 70 keV, while SE had an average deviation of 11.8%. Conclusions: The authors’ report demonstrates, across all phantom sizes, the improvement in CT number stability achieved with mono and mono+ relative to SE

Technical Note: Improved CT number stability across patient size using dual-energy CT virtual monoenergetic imaging

Energy Technology Data Exchange (ETDEWEB)

Michalak, Gregory; Grimes, Joshua; Fletcher, Joel; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia, E-mail: mccollough.cynthia@mayo.edu [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Halaweish, Ahmed [Siemens Medical Solutions, Malvern, Pennsylvania 19355 (United States)

2016-01-15

Purpose: The purpose of this study was to evaluate, over a wide range of phantom sizes, CT number stability achieved using two techniques for generating dual-energy computed tomography (DECT) virtual monoenergetic images. Methods: Water phantoms ranging in lateral diameter from 15 to 50 cm and containing a CT number test object were scanned on a DSCT scanner using both single-energy (SE) and dual-energy (DE) techniques. The SE tube potentials were 70, 80, 90, 100, 110, 120, 130, 140, and 150 kV; the DE tube potential pairs were 80/140, 70/150Sn, 80/150Sn, 90/150Sn, and 100/150Sn kV (Sn denotes that the 150 kV beam was filtered with a 0.6 mm tin filter). Virtual monoenergetic images at energies ranging from 40 to 140 keV were produced from the DECT data using two algorithms, monoenergetic (mono) and monoenergetic plus (mono+). Particularly in large phantoms, water CT number errors and/or artifacts were observed; thus, datasets with water CT numbers outside ±10 HU or with noticeable artifacts were excluded from the study. CT numbers were measured to determine CT number stability across all phantom sizes. Results: Data exclusions were generally limited to cases when a SE or DE technique with a tube potential of less than 90 kV was used to scan a phantom larger than 30 cm. The 90/150Sn DE technique provided the most accurate water background over the large range of phantom sizes evaluated. Mono and mono+ provided equally improved CT number stability as a function of phantom size compared to SE; the average deviation in CT number was only 1.4% using 40 keV and 1.8% using 70 keV, while SE had an average deviation of 11.8%. Conclusions: The authors’ report demonstrates, across all phantom sizes, the improvement in CT number stability achieved with mono and mono+ relative to SE.

Role of Bronchoscopy in Malignant Pleural effusion

Directory of Open Access Journals (Sweden)

Gomathi. R. G.

2016-04-01

Full Text Available The aim of this study was to assess the role of Bronchoscopy in plural effusion in cancer condition. Pleural effusion is one of the commonest problems with which patients present to the hospital. Around a million patients worldwide develop pleural effusion each year. This is a Prospective and Observational Study. All patients diagnosed to have pleural effusion by xray, clinical examination and ultrasound examination of pleura if needed will undergo informed. All 32 patients underwent bronchoscopy procedure, 30 patients had endobronchial mass and biopsy was done which was positive for malignancy and 2 patients had bronchial wash cytology positive for malignancy We conclude that bronchoscopy has a definite role in the etiological diagnosis of pleural effusion.

Automatic Segmentation and Online virtualCT in Head-and-Neck Adaptive Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Peroni, Marta, E-mail: marta.peroni@mail.polimi.it [Department of Bioengineering, Politecnico di Milano, Milano (Italy); Ciardo, Delia [Advanced Radiotherapy Center, European Institute of Oncology, Milano (Italy); Spadea, Maria Francesca [Department of Experimental and Clinical Medicine, Universita degli Studi Magna Graecia, Catanzaro (Italy); Riboldi, Marco [Department of Bioengineering, Politecnico di Milano, Milano (Italy); Bioengineering Unit, Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); Comi, Stefania; Alterio, Daniela [Advanced Radiotherapy Center, European Institute of Oncology, Milano (Italy); Baroni, Guido [Department of Bioengineering, Politecnico di Milano, Milano (Italy); Bioengineering Unit, Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); Orecchia, Roberto [Advanced Radiotherapy Center, European Institute of Oncology, Milano (Italy); Universita degli Studi di Milano, Milano (Italy); Medical Department, Centro Nazionale di Adroterapia Oncologica, Pavia (Italy)

2012-11-01

Purpose: The purpose of this work was to develop and validate an efficient and automatic strategy to generate online virtual computed tomography (CT) scans for adaptive radiation therapy (ART) in head-and-neck (HN) cancer treatment. Method: We retrospectively analyzed 20 patients, treated with intensity modulated radiation therapy (IMRT), for an HN malignancy. Different anatomical structures were considered: mandible, parotid glands, and nodal gross tumor volume (nGTV). We generated 28 virtualCT scans by means of nonrigid registration of simulation computed tomography (CTsim) and cone beam CT images (CBCTs), acquired for patient setup. We validated our approach by considering the real replanning CT (CTrepl) as ground truth. We computed the Dice coefficient (DSC), center of mass (COM) distance, and root mean square error (RMSE) between correspondent points located on the automatically segmented structures on CBCT and virtualCT. Results: Residual deformation between CTrepl and CBCT was below one voxel. Median DSC was around 0.8 for mandible and parotid glands, but only 0.55 for nGTV, because of the fairly homogeneous surrounding soft tissues and of its small volume. Median COM distance and RMSE were comparable with image resolution. No significant correlation between RMSE and initial or final deformation was found. Conclusion: The analysis provides evidence that deformable image registration may contribute significantly in reducing the need of full CT-based replanning in HN radiation therapy by supporting swift and objective decision-making in clinical practice. Further work is needed to strengthen algorithm potential in nGTV localization.

Automatic segmentation and online virtualCT in head-and-neck adaptive radiation therapy.

Science.gov (United States)

Peroni, Marta; Ciardo, Delia; Spadea, Maria Francesca; Riboldi, Marco; Comi, Stefania; Alterio, Daniela; Baroni, Guido; Orecchia, Roberto

2012-11-01

The purpose of this work was to develop and validate an efficient and automatic strategy to generate online virtual computed tomography (CT) scans for adaptive radiation therapy (ART) in head-and-neck (HN) cancer treatment. We retrospectively analyzed 20 patients, treated with intensity modulated radiation therapy (IMRT), for an HN malignancy. Different anatomical structures were considered: mandible, parotid glands, and nodal gross tumor volume (nGTV). We generated 28 virtualCT scans by means of nonrigid registration of simulation computed tomography (CTsim) and cone beam CT images (CBCTs), acquired for patient setup. We validated our approach by considering the real replanning CT (CTrepl) as ground truth. We computed the Dice coefficient (DSC), center of mass (COM) distance, and root mean square error (RMSE) between correspondent points located on the automatically segmented structures on CBCT and virtualCT. Residual deformation between CTrepl and CBCT was below one voxel. Median DSC was around 0.8 for mandible and parotid glands, but only 0.55 for nGTV, because of the fairly homogeneous surrounding soft tissues and of its small volume. Median COM distance and RMSE were comparable with image resolution. No significant correlation between RMSE and initial or final deformation was found. The analysis provides evidence that deformable image registration may contribute significantly in reducing the need of full CT-based replanning in HN radiation therapy by supporting swift and objective decision-making in clinical practice. Further work is needed to strengthen algorithm potential in nGTV localization. Copyright © 2012 Elsevier Inc. All rights reserved.

Value of Virtual Colonoscopy with 64 Row CT in Evaluation of Colorectal Cancer

International Nuclear Information System (INIS)

Zaleska-Dorobisz, Urszula; Łasecki, Mateusz; Nienartowicz, Ewa; Pelak, Joanna; Słonina, Joanna; Olchowy, Cyprian; Ścieżka, Marek; Sąsiadek, Marek

2014-01-01

Virtual colonoscopy (VC) enables three-dimensional view of walls and internal lumen of the colon as a result of reconstruction of multislice CT images. The role of VC in diagnosis of the colon abnormalities systematically increases, and in many medical centers all over the world is carried out as a screening test of patients with high risk of colorectal cancer. We analyzed results of virtual colonoscopy of 360 patients with clinical suspicion of colorectal cancer. Sensitivity and specificity of CT colonoscopy for detection of colon cancers and polyps were assessed. Results of our research have shown high diagnostic efficiency of CT colonoscopy in detection of focal lesions in large intestine of 10 mm or more diameter. Sensitivity was 85.7%, specificity 89.2%. Virtual colonoscopy is noninvasive and well tolerated by patients imaging method, which permits for early detection of the large intestine lesions with specificity and sensitivity similar to classical colonoscopy in screening exams in patients suspected for colorectal cancer. Good preparation of the patients for the examination is very important for proper diagnosis and interpretation of this imaginge procedure

The role of CT in the diagnosis of bronchogenic carcinoma not detected by plain radiograph

International Nuclear Information System (INIS)

Choi, Byoung Wook; Choe, Kyu Ok; Lee, Je Hyuk; Ryu, Seok Jong

2000-01-01

To evaluate the role of CT and CT features in the diagnosis of bronchogenic carcinomas not detected by plain radiography. Eighteen patients [19 primary cancer lesions, M:F=16:2, aged 43-75 (mean, 56.3) years] with lung cancer initially not detected by plain radiography were involved in this study. CT scanning was performed in all cases, and fibrobronchoscopy, and sputum cytology, each in 17. Lesions were divided into two groups: the central type, if on or proximal to the segmental bronchus, and the peripheral type, if distal to this. Plain radiographs were analysed for possible causes of occultness and for clinical characteristics including cell type, location, and size. We focused on the CT findings, comparing cases undetected by CT with those undetected by bronchoscopy. In the central type, the cause of occultness, as seen on plain radiographs, was small size, no secondary findings, or confusing shadow from hilar vessels. In the peripheral type, the cause was overlapping shadow due to normal structures of the chest, or combined diseases. Eight lesions were first detected by sputum cytology, 6 by bronchoscopy, and 5 by CT. Fourteen lesions were the central type (main bronchus 2, lobar bronchus 7, segmental bronchus 5), and five were peripheral. Central-type lesions were either squamous cell carcinoma (n=11), adenocarcinoma (n=1), small cell carcinoma (n=1), or large cell carcinoma (n=1). The peripheral type were either squamous cell carcinoma (n=2), adenocarcinoma (n=2), or large cell carcinoma (n=1). Size ranged from 0.2 to 4(mean, 2; central 1.7, peripheral 2.8) cm. Surgical resection was possible in 15 patients (16 cancers, including 13 at stage I). Only two were at a stage which rendered them unresectable. CT revealed 13 cancers, including all those which were peripheral. The finding were endobronchial nodule (n=4), bronchial wall thickening (n=1), perihilar mass (n=3), parenchymal mass (n=2), and subpleural mass (n=3). In six central-type cases [endobronchial

Importance of flexible bronchoscopy in decannulation of tracheostomy patients

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Leonardo Brand Rodrigues

Full Text Available OBJECTIVE: To evaluate the importance of flexible bronchoscopy in tracheostomy patients in the process of decannulation to assess the incidence and types of laryngotracheal injury and compare the presence of such lesions with clinical criteria used for decannulation. METHODS: We studied 51 tracheostomized patients aged between 19 and 87 years, with tracheal stent for a mean of 46 ± 28 days and with clinical criteria for decannulation. They were submitted to tracheostomy tube occlusion tolerance testfor 24 hours, and then to flexible bronchoscopy. We described and classified the diagnosed laryngotracheal changes. We compared the clinical criteria for decannulation indication with the bronchoscopy-diagnosed laryngotracheal injuries that contraindicated decannulation. We identified the factors that could interfere in decannulation and evaluated the importance of bronchoscopy as part of the process. RESULTS: Forty (80.4% patients had laryngotracheal alterations. Of the 40 patients considered clinically fit to decannulation, eight (20% (p = 0.0007 presented with laryngotracheal injuries at bronchoscopy that contraindicated the procedure. The most frequent laryngeal alteration was vocal cords lesion, in 15 (29% individuals, and granuloma, the most prevalent tracheal lesion, in 14 (27.5% patients. CONCLUSION: flexible bronchoscopy showed a large number of laryngotracheal injuries, the most frequent being the vocal cords injury in the larynx and the granuloma in the trachea, which contributed to increase the decannulation procedure safety.

Computer-based route-definition system for peripheral bronchoscopy.

Science.gov (United States)

Graham, Michael W; Gibbs, Jason D; Higgins, William E

2012-04-01

Multi-detector computed tomography (MDCT) scanners produce high-resolution images of the chest. Given a patient's MDCT scan, a physician can use an image-guided intervention system to first plan and later perform bronchoscopy to diagnostic sites situated deep in the lung periphery. An accurate definition of complete routes through the airway tree leading to the diagnostic sites, however, is vital for avoiding navigation errors during image-guided bronchoscopy. We present a system for the robust definition of complete airway routes suitable for image-guided bronchoscopy. The system incorporates both automatic and semiautomatic MDCT analysis methods for this purpose. Using an intuitive graphical user interface, the user invokes automatic analysis on a patient's MDCT scan to produce a series of preliminary routes. Next, the user visually inspects each route and quickly corrects the observed route defects using the built-in semiautomatic methods. Application of the system to a human study for the planning and guidance of peripheral bronchoscopy demonstrates the efficacy of the system.

Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT).

Science.gov (United States)

Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

2016-01-01

During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CT vlab ) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CT vlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CT vlab can be accessed either on a normal computer or through a dedicated version for mobile devices.

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.)

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

International Nuclear Information System (INIS)

Sun, Z.; Allen, Y.; Fitzsimmons, B.; Hartely, D.; Lawrence-Brown, M.

2007-01-01

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.)

Subinterlobular Pleural Location Is a Risk Factor for Pneumothorax After Bronchoscopy.

Science.gov (United States)

Chino, Haruka; Iikura, Motoyasu; Saito, Nayuta; Sato, Nahoko; Suzuki, Manabu; Ishii, Satoru; Morino, Eriko; Naka, Go; Takasaki, Jin; Izumi, Shinyu; Hojo, Masayuki; Takeda, Yuichiro; Sugiyama, Haruhito

2016-12-01

Pneumothorax is one of the most important complications after bronchoscopy. This study was conducted to determine the risk factors for post-bronchoscopy pneumothorax. We retrospectively reviewed the medical records of 23 consecutive subjects who were diagnosed with iatrogenic pneumothorax after bronchoscopy between August 2010 and February 2014. Forty-six control subjects who did not develop pneumothorax after bronchoscopy were randomly selected. The factors affecting the occurrence of pneumothorax were determined by univariate and multivariate analyses. Among 991 patients who underwent bronchoscopy during the study period, 23 (2.3%) developed pneumothorax after bronchoscopy. Among these 23 subjects, 13 (57%) required chest tube drainage. Compared with the control group (46 randomly selected from 968 subjects who did not develop pneumothorax), the group that developed pneumothorax had a preponderance of women and had more target lesions located in the subpleural area (odds ratio [OR] 7.8, 95% CI 0.9-64), especially those that were close to the interlobular pleura (OR 5.1, 95% CI 1.6-16.1) and the left lung (OR 3.2, 95% CI 1.1-9.5). Multivariate analysis revealed that a subinterlobular pleural location of a lesion was a risk factor for pneumothorax (OR 4.8, 95% CI 1.1-20.4). Pneumothorax occurred significantly more frequently when bronchoscopy was performed for subinterlobular pleural lesions. Close attention and care should be taken during bronchoscopy, especially when target lesions are abutting the interlobular pleura. Copyright © 2016 by Daedalus Enterprises.

Effectiveness of bronchoscopy in the diagnosis of bronchial-type mycobacterium avium-intracellulare complex pulmonary disease

International Nuclear Information System (INIS)

Sato, Kazuhiro; Kourakata, Hiroyo

2004-01-01

Mycobacterium avium-intracellulare complex (MAC) pulmonary disease with associated nodules and bronchiectasis is an increasingly prevalent condition. This condition is often difficult to diagnose in the early stages of the disease, because of the limited effectiveness of sputum culture cytology. The effectiveness of bronchoscopy in the isolation and diagnosis of MAC in respiratory secretions is still unclear. Over a three-year period, we examined the effectiveness of bronchoscopy in 45 non-HIV-infected patients who had clusters of small peripheral lung nodules. These nodules were associated with changes of the draining bronchi detected by high-resolution CT (HRCT). A total of 22 of 45 patients (48.9%) had cultures positive for MAC. In the MAC-positive group, 10 patients tested positive for disease in sputum and 22 tested positive for disease in bronchial washings. A total of 13 of 45 patients (28.9%) fulfilled the American Thoracic Society criteria for pulmonary MAC disease, and 9 (20.0%) others with cultures positive for MAC did not fulfill the criteria. Radiographic measures and sputum cultures of 13 of 16 patients (81.3%) with negative cultures revealed no further disease progression. We found that HRCT was a useful technique in the diagnosis of MAC-pulmonary disease. We also found that bronchoscopy was a more sensitive diagnostic technique than sputum culture, analysis in the differential diagnosis of MAC pulmonary diseases. (author)

Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

International Nuclear Information System (INIS)

Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T.

2004-01-01

Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P [de

Inexpensive anatomical trainer for bronchoscopy.

Science.gov (United States)

Di Domenico, Stefano; Simonassi, Claudio; Chessa, Leonardo

2007-08-01

Flexible fiberoptic bronchoscopy is an indispensable tool for optimal management of intensive care unit patients. However, the acquisition of sufficient training in bronchoscopy is not straightforward during residency, because of technical and ethical problems. Moreover, the use of commercial simulators is limited by their high cost. In order to overcome these limitations, we realized a low-cost anatomical simulator to acquire and maintain the basic skill to perform bronchoscopy in ventilated patients. We used 1.5 mm diameter iron wire to construct the bronchial tree scaffold; glazier-putty was applied to create the anatomical model. The model was covered by several layers of newspaper strips previously immersed in water and vinilic glue. When the model completely dried up, it was detached from the scaffold by cutting it into six pieces, it was reassembled, painted and fitted with an endotracheal tube. We used very cheap material and the final cost was euro16. The trainer resulted in real-scale and anatomically accurate, with appropriate correspondence on endoscopic view between model and patients. All bronchial segments can be explored and easily identified by endoscopic and external vision. This cheap simulator is a valuable tool for practicing, particularly in a hospital with limited resources for medical training.

Immersive Virtual Reality for Visualization of Abdominal CT.

Science.gov (United States)

Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A; Bodenheimer, Robert E

2013-03-28

Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two-dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

Immersive virtual reality for visualization of abdominal CT

Science.gov (United States)

Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A.; Bodenheimer, Robert E.

2013-03-01

Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

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

International Nuclear Information System (INIS)

Lee, Whal; Chung, Jin-Wook; Kang, Heung-Sik; Hong, Sung-Hwan; Choi, Ja-Young; Kim, Ho-Sung; Kim, Seok-Jung; Kim, Hyung-Ho

2004-01-01

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

Dual-energy CT in the evaluation of solitary pulmonary nodules by virtual non-enhanced images: initial experience

International Nuclear Information System (INIS)

Guo Xing; Ding Wei; Qin Huijuan

2011-01-01

Objective: To determine the accuracy and radiation dose of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs) by virtual non-enhanced images. Methods: Sixty-one patients with SPNs including 39 malignant and 18 benign nodules proved by pathology underwent DECT scans. The CT values of SPNs on enhanced weighted average and virtual non-enhanced images were compared by using Liver VNC processing unit in terms of their diagnostic accuracy for distinguishing malignant and benign nodules with a 20 HU threshold. Diagnostic accuracy was compared. In 28 patients of all patients, image noise and quality score of the non-enhanced and virtual non-enhanced images were compared, and radiation doses of each patient were recorded. The paired t test was used to analyze the noise difference between the plain scan and virtual non-enhanced scan. The Mann-Whitney U test. was used to analyze statistically significant differences of the image quality score and radiation dose between the non-enhanced scan and virtual non-enhanced scan. Results: The sensitivity, specificity and accuracy for distinguishing benign and malignant nodules by using the virtual non-enhanced image of were 89.7% (35/39), 72.2% (13/18), 84.2% (48/57) respectively. The noise of common CT and virtual non- enhanced images were (8.49±1.94) HU and (10.14±2.18) HU, and there were statistically difference (t=9.45, P 0.05). The radiation doses of common CT and DECT were (3.72±0.48) mSv and (3.78±0.45) mSv, and there were no statistical difference (U= 350.50, P>0.05). Conclusion: DECT by using virtual non-enhanced images is useful tool to distinguish the benign and malignant SPN without additional radiation dose. (authors)

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients

Science.gov (United States)

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F.; Long, Daniel J.; Bolch, Wesley E.; Liu, Bob; Xu, X. George

2015-07-01

This paper describes the development and testing of VirtualDose—a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the ‘software as a service (SaaS)’ delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose’s functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT—two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations.

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients

International Nuclear Information System (INIS)

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F; Xu, X George; Long, Daniel J; Bolch, Wesley E; Liu, Bob

2015-01-01

This paper describes the development and testing of VirtualDose—a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the ‘software as a service (SaaS)’ delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose’s functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT—two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations. (paper)

CT findings of plastic bronchitis in children after a Fontan operation

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea); Jhang, Won Kyoung; Kim, Young Hwee; Ko, Jae Kon; Park, In Sook [University of Ulsan College of Medicine, Department of Pediatric Cardiology, Asan Medical Center, Seoul (Korea); Park, Jeong-Jun; Yun, Tae-Jin; Seo, Dong-Man [University of Ulsan College of Medicine, Department of Pediatric Cardiac Surgery, Asan Medical Center, Seoul (Korea)

2008-09-15

Plastic bronchitis is a rare cause of acute obstructive respiratory failure in children. Life-threatening events are much more frequent in patients with repaired cyanotic congenital heart disease, and most frequent following a Fontan operation. Commonly, the diagnosis is not made until bronchial casts are expectorated. Detailed CT findings in plastic bronchitis have not been described. To describe the CT findings in plastic bronchitis in children after a Fontan operation. Three children with plastic bronchitis after a Fontan operation were evaluated by chest CT. Bronchial casts were spontaneously expectorated and/or extracted by bronchoscopy. Airway and lung abnormalities seen on CT were analyzed in the three children. CT demonstrated bronchial casts in the central airways with associated atelectasis and consolidation in all children. The affected airways were completely or partially obstructed by the bronchial casts without associated bronchiectasis. The airway and lung abnormalities rapidly improved after removal of the bronchial casts. CT can identify airway and lung abnormalities in children with plastic bronchitis after a Fontan operation. In addition, CT can be used to guide bronchoscopy and to monitor treatment responses, and thereby may improve clinical outcomes. (orig.)

Three dimensional volume rendering virtual endoscopy of the ossicles using a multi-row detector CT: applications and limitations

International Nuclear Information System (INIS)

Kim, Su Yeon; Choi, Sun Seob; Kang, Myung Jin; Shin, Tae Beom; Lee, Ki Nam; Kang, Myung Koo

2005-01-01

This study was conducted to know the applications and limitations of three dimensional volume rendering virtual endoscopy of the ossicles using a multi-row detector CT. This study examined 25 patients who underwent temporal bone CT using a 16-row detector CT as a result of hearing problems or trauma. The axial CT scan of the temporal bone was performed with a 0.6 mm collimation, and a reconstruction was carried out with a U70u sharp of kernel value, a 1 mm thickness and 0.5-1.0 mm increments. After observing the ossicles in the axial and coronal images, virtual endoscopy was performed using a three dimensional volume rendering technique with a threshold value of-500 HU. The intra-operative otoendoscopy was performed in 12 ears, and was compared with the virtual endoscopy findings. Virtual endoscopy of the 29 ears without hearing problems demonstrated hypoplastic or an incomplete depiction of the stapes superstructures in 25 ears and a normal depiction in 4 ears. Virtual endoscopy of 21 ears with hearing problems demonstrated no ossicles in 1 ears, no malleus in 3 ears, a malleoincudal subluxation in 6 ears, a dysplastic incus in 5 ears, an incudostapedial subluxation in 9 ears, dysplastic stapes in 2 ears, a hypoplastic or incomplete depiction of the stapes in 16 ears and no stapes in 1 ears. In contrast to the intra-operative otoendoscopy, 8 out of 12 ears showed a hypoplastic or deformed stapes in the virtual endoscopy. Volume rendering virtual endoscopy using a multi-row detector CT is an excellent method for evaluation the ossicles in three dimension, even thought the partial volume effect for the stapes superstructures needs to be considered

Evaluation of a low-cost, 3D-printed model for bronchoscopy training.

Science.gov (United States)

Parotto, Matteo; Jiansen, Joshua Qua; AboTaiban, Ahmed; Ioukhova, Svetlana; Agzamov, Alisher; Cooper, Richard; O'Leary, Gerald; Meineri, Massimiliano

2017-01-01

Flexible bronchoscopy is a fundamental procedure in anaesthesia and critical care medicine. Although learning this procedure is a complex task, the use of simulation-based training provides significant advantages, such as enhanced patient safety. Access to bronchoscopy simulators may be limited in low-resource settings. We have developed a low-cost 3D-printed bronchoscopy training model. A parametric airway model was obtained from an online medical model repository and fabricated using a low-cost 3D printer. The participating physicians had no prior bronchoscopy experience. Participants received a 30-minute lecture on flexible bronchoscopy and were administered a 15-item pre-test questionnaire on bronchoscopy. Afterwards, participants were instructed to perform a series of predetermined bronchoscopy tasks on the 3D printed simulator on 4 consecutive occasions. The time needed to perform the tasks and the quality of task performance (identification of bronchial anatomy, technique, dexterity, lack of trauma) were recorded. Upon completion of the simulator tests, participants were administered the 15-item questionnaire (post-test) once again. Participant satisfaction data on the perceived usefulness and accuracy of the 3D model were collected. A statistical analysis was performed using the t-test. Data are reported as mean values (± standard deviation). The time needed to complete all tasks was 152.9 ± 71.5 sec on the 1st attempt vs. 98.7 ± 40.3 sec on the 4th attempt (P = 0.03). Likewise, the quality of performance score improved from 8.3 ± 6.7 to 18.2 ± 2.5 (P 3D-printed model for bronchoscopy training. This model improved trainee performance and may represent a valid, low-cost bronchoscopy training tool.

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

Virtual planning of dental implant placement using CT double scan-technique - own experience

International Nuclear Information System (INIS)

Wojciechowski, W.; Urbanik, A.; Kownacki, P.; Kownacki, S.

2007-01-01

The correctness of CT performed with the use of a double-scan technique is the basis for achieving proper quality of 3D reconstructions of the maxilla or mandible and subsequent virtual planning of dental implant placement. The aim of this study was the presentation of the methodology of computed tomography scanning and own experience with the use of the double-scan technique. The study group included 26 individuals who underwent MDCT with a double-scan technique using a MDCT scanner SOMATOM Sensation (Siemens, Germany). The parameters of the examination: slice-collimation 10 x 0.75 mm, slice-thickness 0.75 mm. The first CT scan in the procedure was the scan of the patient wearing a radiological prosthesis and occlusal index, which was followed by a separate scan of the radiological prosthesis. These two CT scans were copied and transferred to PC with Procera Software program (Nobel Biocare, Sweden) where dental implant placement was virtually planned. In all 26 patients, precise three-dimensional reconstructions of the anatomical structure were obtained. In 11 patients, on the basis of the virtual planning, the implant placement was performed, 5 patients were referred to preparatory procedures, that is, restoration of the alveolar process, otolaryngological treatment of the maxillary sinuses. The remaining 10 patients did not qualify to the procedure because of unfavorable anatomical ideation's. Correct computed tomography with double-scan technique enables virtual planning of dental implant placement, on the basis of which the real procedure of implantation can be performed. (author)

Establishing Pass/Fail Criteria for Bronchoscopy Performance

DEFF Research Database (Denmark)

Konge, Lars; Clementsen, Paul; Larsen, Klaus Richter

2012-01-01

Background: Several tools have been created to assess competence in bronchoscopy. However, educational guidelines still use an arbitrary number of performed procedures to decide when basic competency is acquired. Objectives: The purpose of this study was to define pass/fail scores for two...... method. In the first we compared bronchoscopy performance scores of 14 novices with the scores of 14 experienced consultants to find the score that best discriminated between the two groups. In the second we asked an expert group of 7 experienced bronchoscopists to judge how a borderline trainee would...

Missed distal tracheal foreign body in consecutive bronchoscopies in a 6-year-old boy

Directory of Open Access Journals (Sweden)

Oghenevware Joel Eyekpegha

2017-01-01

Full Text Available It is unusual but not uncommon for foreign bodies to be missed at bronchoscopy. This case report highlights the importance of the clinical history in the diagnosis of aspirated foreign bodies and the usefulness of chest imaging modalities. A 6-year-old boy presented with recurrent breathlessness and cough of 2 months. He was said to have aspirated the base cap of a pen at about the time symptoms started. He had two sessions of rigid bronchoscopy and a session of flexible bronchoscopy at three different hospitals. He had an initial rigid bronchoscopy which failed to show the foreign body (FB. A chest computerized tomographic scan demonstrated the FB, which was retrieved at combined flexible/rigid bronchoscopy. Although rigid bronchoscopy is the gold standard for managing airway foreign bodies, there remains a false negative rate for this procedure and where necessary, appropriate imaging may compliment rigid bronchoscopy, especially where there is some confusion.

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

DEFF Research Database (Denmark)

Stolfi, Alessandro; De Chiffre, Leonardo

2018-01-01

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....... The comparison demonstrated that: (i) a tangible improvement in the use of CT compared to previous comparisons; (ii) most of the participants were able to reduce their scanning time by more than 70% without increasing the length measurement errors; and (iii) most of the participants can further reduce...... their uncertainties, thereby reducing the tolerance size that can be inspected using CT in industry....

TU-F-18A-09: CT Number Stability Across Patient Sizes Using Virtual-Monoenergetic Dual-Energy CT

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Michalak, G; Grimes, J; Fletcher, J; McCollough, C [Mayo Clinic, Rochester, MN (United States); Halaweish, A [Siemens Healthcare, Rochester, MN (United States)

2014-06-15

Purpose: Virtual-monoenergetic imaging uses dual-energy CT data to synthesize images corresponding to a single photon energy, thereby reducing beam-hardening artifacts. This work evaluated the ability of a commercial virtual-monoenergetic algorithm to achieve stable CT numbers across patient sizes. Methods: Test objects containing a range of iodine and calcium hydroxyapatite concentrations were placed inside 8 torso-shaped water phantoms, ranging in lateral width from 15 to 50 cm, and scanned on a dual-source CT system (Siemens Somatom Force). Single-energy scans were acquired from 70-150 kV in 10 kV increments; dual-energy scans were acquired using 4 energy pairs (low energy: 70, 80, 90, and 100 kV; high energy: 150 kV + 0.6 mm Sn). CTDIvol was matched for all single- and dual-energy scans for a given phantom size. All scans used 128×0.6 mm collimation and were reconstructed with 1-mm thickness at 0.8-mm increment and a medium smooth body kernel. Monoenergetic images were generated using commercial software (syngo Via Dual Energy, VA30). Iodine contrast was calculated as the difference in mean iodine and water CT numbers from respective regions-of-interest in 10 consecutive images. Results: CT numbers remained stable as phantom width varied from 15 to 50 cm for all dual-energy data sets (except for at 50 cm using 70/150Sn due to photon starvation effects). Relative to the 15 cm phantom, iodine contrast was within 5.2% of the 70 keV value for phantom sizes up to 45 cm. At 90/150Sn, photon starvation did not occur at 50 cm, and iodine contrast in the 50-cm phantom was within 1.4% of the 15-cm phantom. Conclusion: Monoenergetic imaging, as implemented in the evaluated commercial system, eliminated the variation in CT numbers due to patient size, and may provide more accurate data for quantitative tasks, including radiation therapy treatment planning. Siemens Healthcare.

CT colonoscopy: sensibility in 2D/4D CT colonoscopy versus virtual endoscopy. Correlation to conventional colonoscopy

International Nuclear Information System (INIS)

Carrascosa, Patricia; Capunay, Carlos; Sanchez, Flavio; Castiglioni, Roberto; Carrascosa, Jorge

2001-01-01

Colorectal carcinoma is the second leading cause of death from malignant tumors. Most large bowel malignancies arise from pre-existing adenomas. In individual older than 50 years the prevalence of polyps and cancer increases. Therefore screening is recommended for average risk individuals in this group. Recently a new technique called 'Virtual Colonoscopy' has appeared. The purpose of this study was to compare the diagnosis accuracy of two dimensional CT Colonoscopy (2D CTC) and Virtual Colonoscopy (VC) individually with Conventional Colonoscopy (CC) and to determine improvement of the Sensitivity (S) and Specificity (E) combining both types of evaluation. Ninety patients were studied (47 women and 43 men). CT studies were obtained on a helical CT scanner. The lesions were studied in supine and prone position. All patients had CC done within 10 hours before CTC. The lesions were divided in 3 groups: 1) 9 mm. Each group was divided into 3 subgroups: a) findings in 2D; b) findings in VC; and c) findings combined. Ninety-two lesions were identified on CC and 101 on CTC. There were 9 false positive in all groups. The statistical analysis showed a high S and E in both 2D and VC. The combination of both methods does not increase significantly the diagnosis of CTC but the S reached 100% because the false negative rate was reduced to 0. (author)

Hybrid 3D visualization of the chest and virtual endoscopy of the tracheobronchial system: possibilities and limitations of clinical application.

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Seemann, M D; Claussen, C D

2001-06-01

A hybrid rendering method which combines a color-coded surface rendering method and a volume rendering method is described, which enables virtual endoscopic examinations using different representation models. 14 patients with malignancies of the lung and mediastinum (n=11) and lung transplantation (n=3) underwent thin-section spiral computed tomography. The tracheobronchial system and anatomical and pathological features of the chest were segmented using an interactive threshold interval volume-growing segmentation algorithm and visualized with a color-coded surface rendering method. The structures of interest were then superimposed on a volume rendering of the other thoracic structures. For the virtual endoscopy of the tracheobronchial system, a shaded-surface model without color coding, a transparent color-coded shaded-surface model and a triangle-surface model were tested and compared. The hybrid rendering technique exploit the advantages of both rendering methods, provides an excellent overview of the tracheobronchial system and allows a clear depiction of the complex spatial relationships of anatomical and pathological features. Virtual bronchoscopy with a transparent color-coded shaded-surface model allows both a simultaneous visualization of an airway, an airway lesion and mediastinal structures and a quantitative assessment of the spatial relationship between these structures, thus improving confidence in the diagnosis of endotracheal and endobronchial diseases. Hybrid rendering and virtual endoscopy obviate the need for time consuming detailed analysis and presentation of axial source images. Virtual bronchoscopy with a transparent color-coded shaded-surface model offers a practical alternative to fiberoptic bronchoscopy and is particularly promising for patients in whom fiberoptic bronchoscopy is not feasible, contraindicated or refused. Furthermore, it can be used as a complementary procedure to fiberoptic bronchoscopy in evaluating airway stenosis and

Management of antithrombotic agents in patients undergoing flexible bronchoscopy

Directory of Open Access Journals (Sweden)

Sami Abuqayyas

2017-07-01

Full Text Available Bleeding is one of the most feared complications of flexible bronchoscopy. Although infrequent, it can be catastrophic and result in fatal outcomes. Compared to other endoscopic procedures, the risk of morbidity and mortality from the bleeding is increased, as even a small amount of blood can fill the tracheobronchial tree and lead to respiratory failure. Patients using antithrombotic agents (ATAs have higher bleeding risk. A thorough understanding of the different ATAs is critical to manage patients during the peri-procedural period. A decision to stop an ATA before bronchoscopy should take into account a variety of factors, including indication for its use and the type of procedure. This article serves as a detailed review on the different ATAs, their pharmacokinetics and the pre- and post-bronchoscopy management of patients receiving these medications.

Image quality characteristics for virtual monoenergetic images using dual-layer spectral detector CT: Comparison with conventional tube-voltage images.

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Sakabe, Daisuke; Funama, Yoshinori; Taguchi, Katsuyuki; Nakaura, Takeshi; Utsunomiya, Daisuke; Oda, Seitaro; Kidoh, Masafumi; Nagayama, Yasunori; Yamashita, Yasuyuki

2018-05-01

To investigate the image quality characteristics for virtual monoenergetic images compared with conventional tube-voltage image with dual-layer spectral CT (DLCT). Helical scans were performed using a first-generation DLCT scanner, two different sizes of acrylic cylindrical phantoms, and a Catphan phantom. Three different iodine concentrations were inserted into the phantom center. The single-tube voltage for obtaining virtual monoenergetic images was set to 120 or 140 kVp. Conventional 120- and 140-kVp images and virtual monoenergetic images (40-200-keV images) were reconstructed from slice thicknesses of 1.0 mm. The CT number and image noise were measured for each iodine concentration and water on the 120-kVp images and virtual monoenergetic images. The noise power spectrum (NPS) was also calculated. The iodine CT numbers for the iodinated enhancing materials were similar regardless of phantom size and acquisition method. Compared with the iodine CT numbers of the conventional 120-kVp images, those for the monoenergetic 40-, 50-, and 60-keV images increased by approximately 3.0-, 1.9-, and 1.3-fold, respectively. The image noise values for each virtual monoenergetic image were similar (for example, 24.6 HU at 40 keV and 23.3 HU at 200 keV obtained at 120 kVp and 30-cm phantom size). The NPS curves of the 70-keV and 120-kVp images for a 1.0-mm slice thickness over the entire frequency range were similar. Virtual monoenergetic images represent stable image noise over the entire energy spectrum and improved the contrast-to-noise ratio than conventional tube voltage using the dual-layer spectral detector CT. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

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

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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.

High-Flow Nasal Interface Improves Oxygenation in Patients Undergoing Bronchoscopy

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Umberto Lucangelo

2012-01-01

Full Text Available During bronchoscopy hypoxemia is commonly found and oxygen supply can be delivered by interfaces fed with high gas flows. Recently, the high-flow nasal cannula (HFNC has been introduced for oxygen therapy in adults, but they have not been used so far during bronchoscopy in adults. Forty-five patients were randomly assigned to 3 groups receiving oxygen: 40 L/min through a Venturi mask (V40, N=15, nasal cannula (N40, N=15, and 60 L/min through a nasal cannula (N60, N=15 during bronchoscopy. Gas exchange and circulatory variables were sampled before (FiO2 = 0.21, at the end of bronchoscopy (FiO2 = 0.5, and thereafter (V40, FiO2 = 0.35. In 8 healthy volunteers oxygen was randomly delivered according to V40, N40, and N60 settings, and airway pressure was measured. At the end of bronchoscopy, N60 presented higher PaO2, PaO2/FiO2, and SpO2 than V40 and N40 that did not differ between them. In the volunteers (N60 median airway pressure amounted to 3.6 cmH2O. Under a flow rate of 40 L/min both the Venturi mask and HFNC behaved similarly, but nasal cannula associated with a 60 L/min flow produced the better results, thus indicating its use in mild respiratory dysfunctions.

Virtual non-contrast computer tomography (CT) with spectral CT as an alternative to conventional unenhanced CT in the assessment of gastric cancer.

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Tian, Shi-Feng; Liu, Ai-Lian; Wang, He-Qing; Liu, Jing-Hong; Sun, Mei-Yu; Liu, Yi-Jun

2015-01-01

The purpose of this study was to evaluate computed tomography (CT) virtual non-contrast (VNC) spectral imaging for gastric carcinoma. Fifty-two patients with histologically proven gastric carcinomas underwent gemstone spectral imaging (GSI) including non-contrast and contrast-enhanced hepatic arterial, portal venous, and equilibrium phase acquisitions prior to surgery. VNC arterial phase (VNCa), VNC venous phase (VNCv), and VNC equilibrium phase (VNCe) images were obtained by subtracting iodine from iodine/water images. Images were analyzed with respect to image quality, gastric carcinoma-intragastric water contrast-to-noise ratio (CNR), gastric carcinoma-perigastric fat CNR, serosal invasion, and enlarged lymph nodes around the lesions. Carcinoma-water CNR values were significantly higher in VNCa, VNCv, and VNCe images than in normal CT images (2.72, 2.60, 2.61, respectively, vs 2.35, p≤0.008). Carcinoma- perigastric fat CNR values were significantly lower in VNCa, VNCv, and VNCe images than in normal CT images (7.63, 7.49, 7.32, respectively, vs 8.48, pVNC arterial phase images may be a surrogate for conventional non-contrast CT images in gastric carcinoma evaluation.

Bronchoscopy Simulation: A Brief Review

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Davoudi, Mohsen; Colt, Henri G.

2009-01-01

More than 500,000 flexible bronchoscopies are performed annually by chest physicians in the United States (Ernst et al., Chest 123:1693-1717, 2003). Indications include diagnosis of lung cancer and airway tumors, benign strictures, pulmonary infections, and treatment of central airway obstruction, emphysema, and intraepithelial lesions such as…

Lung cancer mimicking lung abscess formation on CT images

OpenAIRE

Taira, Naohiro; Kawabata, Tsutomu; Gabe, Atsushi; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawasaki, Hidenori; Yamashiro, Toshimitsu; Ishikawa, Kiyoshi

2014-01-01

Patient: Male, 64 Final Diagnosis: Lung pleomorphic carcinoma Symptoms: Cough • fever Medication: — Clinical Procedure: — Specialty: Oncology Objective: Unusual clinical course Background: The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resemble...

Accuracy of Dual-Energy Virtual Monochromatic CT Numbers: Comparison between the Single-Source Projection-Based and Dual-Source Image-Based Methods.

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Ueguchi, Takashi; Ogihara, Ryota; Yamada, Sachiko

2018-03-21

To investigate the accuracy of dual-energy virtual monochromatic computed tomography (CT) numbers obtained by two typical hardware and software implementations: the single-source projection-based method and the dual-source image-based method. A phantom with different tissue equivalent inserts was scanned with both single-source and dual-source scanners. A fast kVp-switching feature was used on the single-source scanner, whereas a tin filter was used on the dual-source scanner. Virtual monochromatic CT images of the phantom at energy levels of 60, 100, and 140 keV were obtained by both projection-based (on the single-source scanner) and image-based (on the dual-source scanner) methods. The accuracy of virtual monochromatic CT numbers for all inserts was assessed by comparing measured values to their corresponding true values. Linear regression analysis was performed to evaluate the dependency of measured CT numbers on tissue attenuation, method, and their interaction. Root mean square values of systematic error over all inserts at 60, 100, and 140 keV were approximately 53, 21, and 29 Hounsfield unit (HU) with the single-source projection-based method, and 46, 7, and 6 HU with the dual-source image-based method, respectively. Linear regression analysis revealed that the interaction between the attenuation and the method had a statistically significant effect on the measured CT numbers at 100 and 140 keV. There were attenuation-, method-, and energy level-dependent systematic errors in the measured virtual monochromatic CT numbers. CT number reproducibility was comparable between the two scanners, and CT numbers had better accuracy with the dual-source image-based method at 100 and 140 keV. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Value of flexible bronchoscopy in the pre-operative work-up of solitary pulmonary nodules.

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Schwarz, Carsten; Schönfeld, Nicolas; Bittner, Roland C; Mairinger, Thomas; Rüssmann, Holger; Bauer, Torsten T; Kaiser, Dirk; Loddenkemper, Robert

2013-01-01

The diagnostic value of flexible bronchoscopy in the pre-operative work-up of solitary pulmonary nodules (SPN) is still under debate among pneumologists, radiologists and thoracic surgeons. In a prospective observational manner, flexible bronchoscopy was routinely performed in 225 patients with SPN of unknown origin. Of the 225 patients, 80.5% had lung cancer, 7.6% had metastasis of an extrapulmonary primary tumour and 12% had benign aetiology. Unsuspected endobronchial involvement was found in 4.4% of all 225 patients (or in 5.5% of patients with lung cancer). In addition, flexible bronchoscopy clarified the underlying aetiology in 41% of the cases. The bronchoscopic biopsy results from the SPN were positive in 84 (46.5%) patients with lung cancer. Surgery was cancelled due to the results of flexible bronchoscopy in four cases (involvement of the right main bronchus (impaired pulmonary function did not allow pneumonectomy) n=1, small cell lung cancer n=1, bacterial pneumonia n=2), and the surgical strategy had to be modified to bilobectomy in one patient. Flexible bronchoscopy changed the planned surgical approach in five cases substantially. These results suggest that routine flexible bronchoscopy should be included in the regular pre-operative work-up of patients with SPN.

Spectral detector CT-derived virtual non-contrast images: comparison of attenuation values with unenhanced CT.

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Ananthakrishnan, Lakshmi; Rajiah, Prabhakar; Ahn, Richard; Rassouli, Negin; Xi, Yin; Soesbe, Todd C; Lewis, Matthew A; Lenkinski, Robert E; Leyendecker, John R; Abbara, Suhny

2017-03-01

To assess virtual non-contrast (VNC) images obtained on a detection-based spectral detector CT scanner and determine how attenuation on VNC images derived from various phases of enhanced CT compare to those obtained from true unenhanced images. In this HIPAA compliant, IRB approved prospective multi-institutional study, 46 patients underwent pre- and post-contrast imaging on a prototype dual-layer spectral detector CT between October 2013 and November 2015, yielding 84 unenhanced and VNC pairs (25 arterial, 39 portal venous/nephrographic, 20 urographic). Mean attenuation was measured by one of three readers in the liver, spleen, kidneys, psoas muscle, abdominal aorta, and subcutaneous fat. Equivalence testing was used to determine if the mean difference between unenhanced and VNC attenuation was less than 5, 10, or 15 HU. VNC image quality was assessed on a 5 point scale. Mean difference between unenhanced and VNC attenuation was VNC attenuation were equivalent in all tissues except fat using a threshold of VNC overestimated the HU relative to unenhanced images. VNC image quality was rated as excellent or good in 84% of arterial phase and 85% of nephrographic phase cases, but only 40% of urographic phase. VNC images derived from novel dual layer spectral detector CT demonstrate attenuation values similar to unenhanced images in all tissues evaluated except for subcutaneous fat. Further study is needed to determine if attenuation thresholds currently used clinically for common pathology should be adjusted, particularly for lesions containing fat.

Virtual Non-Contrast CT Using Dual-Energy Spectral CT: Feasibility of Coronary Artery Calcium Scoring.

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Song, Inyoung; Yi, Jeong Geun; Park, Jeong Hee; Kim, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

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 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 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 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.

Bronchoscopy findings in children with recurrent and chronic stridor.

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Najada, Abdelhamid S; Dahabreh, Muna M

2011-01-01

To describe the bronchoscopic findings and treatment decision of children with chronic or recurrent stridor referred to the pediatric respiratory clinic at Queen Rania Hospital for Children. All children who underwent flexible bronchoscopy at the pediatric bronchoscopy unit for chronic stridor from January 2009 to January 2010 were included. Stridor was divided into 3 groups: inspiratory, expiratory, or biphasic. All patients from 2 weeks of age till 14 years were included. Files of these patients were retrospectively reviewed. A specially formulated data sheet including clinical history and physical findings, type of stridor, bronchoscopic findings, and management decision was used. Radiologic investigation results were included when relevant. Flexible bronchoscopy was performed under sedation and topical anesthesia. A total of 64 children [35 (54.7%) male and 29 (45.3%) female] were included. Twenty-four patients had inspiratory stridor. There were 33 patients with biphasic stridor (subglottic stenosis in 9, paradoxical vocal cord movement in 6, vascular ring in 5, subglottic hemangioma in 3, vocal cord paralyses in 4, foreign body in 2, laryngeal web in 2, and absent vocal cord and tracheal bronchus in 1 each). Seven children had expiratory stridor. Of patients with laryngomalacia, 50% had associated tracheomalacia and 70% of those with laryngomalacia and all patients with tracheomalacia had associated gastroesophageal reflux. Two patients with paradoxical vocal cord movement were found to have Arnold-Chiari malformation. All patients with vascular rings underwent surgery. Flexible bronchoscopy should be performed in all patients with chronic or recurrent stridor to assess the airway and guide further investigations and management.

Advanced virtual monoenergetic images: improving the contrast of dual-energy CT pulmonary angiography

International Nuclear Information System (INIS)

Meier, A.; Wurnig, M.; Desbiolles, L.; Leschka, S.; Frauenfelder, T.; Alkadhi, H.

2015-01-01

Aim: To investigate the value of advanced virtual monoenergetic image reconstruction (mono-plus) from dual-energy computed tomography (CT) for improving the contrast of CT pulmonary angiography (CTPA). Materials and methods: Forty consecutive patients (25 women, mean 62.5 years, range 28–87 years) underwent 192-section dual-source CTPA with dual-energy CT (90/150 SnkVp) after the administration of 60 ml contrast media (300 mg iodine/ml). Conventional virtual monochromatic images at 60 keV and 17 mono-plus image datasets from 40–190 keV (in 10 keV steps) were reconstructed. Subjective image quality (artefacts, subjective noise) was rated. Attenuation was measured in the pulmonary trunk and in the right lower lobe pulmonary artery; noise was measured in the periscapular musculature. The signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated for each patient and dataset. Comparisons between monochromatic images and mono-plus images were performed by repeated measures analysis of variance (ANOVA) with post-hoc Bonferroni correction. Results: Interreader agreement was good to excellent for subjective image quality (ICC: 0.616–0.889). As compared to conventional 60 keV images, artefacts occurred less (p=0.001) and subjective noise was rated lower (p<0.001) in mono-plus 40 keV images. Noise was lower (p<0.001), and the SNR and CNR in the pulmonary trunk and right lower lobe pulmonary artery were higher (both, p<0.001) in mono-plus 40 keV images compared to conventional monoenergetic 60 keV images. Transient interruption of contrast (TIC) was found in 14/40 (35%) of patients, with subjective contrast being similar 8/40 (20%) or higher 32/40 (80%) in mono-plus 40 keV as compared to conventional monoenergetic 60 keV images. Conclusions: Compared to conventional virtual monoenergetic imaging, mono-plus images at 40 keV improve the contrast of dual-energy CTPA. - Highlights: • Advanced monoenergetic image reconstruction from dual-energy CT

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

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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 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. • 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.

Virtual colonoscopy

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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 ...

Distributed practice. The more the merrier? A randomised bronchoscopy simulation study.

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Bjerrum, Anne Sofie; Eika, Berit; Charles, Peder; Hilberg, Ole

2016-01-01

The distribution of practice affects the acquisition of skills. Distributed practice has shown to be more effective for skills acquisition than massed training. However, it remains unknown as to which is the most effective distributed practice schedule for learning bronchoscopy skills through simulation training. This study compares two distributed practice schedules: One-day distributed practice and weekly distributed practice. Twenty physicians in training were randomly assigned to one-day distributed or weekly distributed bronchoscopy simulation practice. Performance was assessed with a pre-test, a post-test after each practice session, and a 4-week retention test using previously validated simulator measures. Data were analysed with repeated measures ANOVA. No interaction was found between group and test (F(4,72) 0.16), except for the measure 'percent-segments-entered', and no main effect of group was found for any of the measures (F(1,72)0.36), which indicates that there was no difference between the learning curves of the one-day distributed practice schedule and the weekly distributed practice schedule. We found no difference in effectiveness of bronchoscopy skills acquisition between the one-day distributed practice and the weekly distributed practice. This finding suggests that the choice of bronchoscopy training practice may be guided by what best suits the clinical practice.

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

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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

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

International Nuclear Information System (INIS)

Milian, F. M.; Attili, A.; Russo, G; Marchetto, F.; Cirio, R.; Bourhaleb, F.

2013-01-01

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)

CT virtual endoscopy: a study of the capability to display the structures and abnormalities in nasal cavity

International Nuclear Information System (INIS)

Han Ping; Brambs, H.J.; Sokiranski, R.

1999-01-01

Objective: To evaluate display ability of virtual endoscopy and its clinical application in comparison with fiberoptic nasal endoscopy. Methods: 11 patients (22 nasal cavities) were examined by virtual endoscopy after axial spiral CT scanning was performed. Virtual endoscopy was performed by Explorer software package in a computer workstation. 9 patients (18 nasal cavities) underwent fiberoptic endoscopy. Results: Virtual endoscopy could clearly demonstrate the anatomical structures in nasal cavity, septal deviation, nasal meatus narrowing and obstruction, turbinate hyperplasia, and pathological masses larger than 3 mm in diameter. However, 'false adhesions' may appear in virtual endoscopy. The main limitation of virtual endoscopy was inability to evaluate mucosa and lack of histological diagnosis. Conclusions: Virtual endoscopy is a new, non-invasive method for demonstrating anatomical structures and diseases in nasal cavity. Its display ability is comparable with fiberoptic nasal endoscopy and is a supplement to fiberoptic nasal endoscopy

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.)

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

International Nuclear Information System (INIS)

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

2017-01-01

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 < 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.)

Remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy: comparison of adjuvant propofol and ketamine

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Mefkur Bakan

2014-06-01

Full Text Available OBJECTIVE:Laryngoscopy and stimuli inside the trachea cause an intense sympatho-adrenal response. Remifentanil seems to be the optimal opioid for rigid bronchoscopy due to its potent and short-acting properties. The purpose of this study was to compare bolus propofol and ketamine as an adjuvant to remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy.MATERIALS AND METHODS:Forty children under 12 years of age who had been scheduled for a rigid bronchoscopy were included in this study. After midazolam premedication, a 1 µg/kg/min remifentanil infusion was started, and patients were randomly allocated to receive either propofol (Group P or ketamine (Group K as well as mivacurium for muscle relaxation. Anesthesia was maintained with a 1 µg/kg/min remifentanil infusion and bolus doses of propofol or ketamine. After the rigid bronchoscopy, 0.05 µg/kg/min of remifentanil was maintained until extubation. Hemodynamic parameters, emergence characteristics, and adverse events were evaluated.RESULTS:The demographic variables were comparable between the two groups. The decrease in mean arterial pressure from baseline values to the lowest values during rigid bronchoscopy was greater in Group P (p= 0.049, while the reduction in the other parameters and the incidence of adverse events were comparable between the two groups. The need for assisted or controlled mask ventilation after extubation was higher in Group K.CONCLUSION:Remifentanil-based total intravenous anesthesia with propofol or ketamine as an adjuvant drug along with controlled ventilation is a viable technique for pediatric rigid bronchoscopy. Ketamine does not provide a definite advantage over propofol with respect to hemodynamic stability during rigid bronchoscopy, while propofol seems more suitable during the recovery period.

High resolution CT for localization of early hilar lung carcinoma

International Nuclear Information System (INIS)

Minami, Yuko; Ishikawa, Shigemi; Saida, Yukihisa; Kajitani, Motomasa; Yamamoto, Tatsuo; Sato, Yukio; Onizuka, Masataka; Sakakibara, Yuzuru; Noguchi, Masayuki

2002-01-01

The purpose of this study was to analyse the usefulness of high resolution CT (HRCT) for the diagnosis and localization of roentgenographically occult lung cancer. HRCT was performed prospectively on chest X-ray negative patients with bloody sputum or suspicious or positive cells on sputum cytology between 1998 and 2000. After the HRCT scan, white light bronchoscopy and autofluorescence bronchoscopy were performed. HRCT depicted 19 hilar bronchial lesions in 13 cases out of 19 patients, of which 9 lesions were confirmed by white light broncoscope. Of 8 hilar squamous cell carcinomas diagnosed in this study, 7 lesions (87.5%) were depicted by HRCT. One CT-negative case (12.5%) was an in situ carcinoma in left B 1+2 . Four out of 20 lesions which showed bronchoscopic abnormality, could not be depicted by HRCT. HRCT could prospectively detect 80% of the bronchoscopic abnormalities and 87.5% of the hilar squamous cell carcinomas of the tracheobronchial lesions of the lung. Therefore, HRCT can be an effective supplemental means for screening for hilar squamous cell carcinoma. (author)

Transconvolution and the virtual positron emission tomograph—A new method for cross calibration in quantitative PET/CT imaging

International Nuclear Information System (INIS)

Prenosil, George A.; Weitzel, Thilo; Hentschel, Michael; Klaeser, Bernd; Krause, Thomas

2013-01-01

Gaussian distribution were introduced. Furthermore, simulation of a virtual PET system provided a standard imaging system with clearly defined properties to which the real PET systems were to be matched. A Hann window served as the modulation transfer function for the virtual PET. The Hann's apodization properties suppressed high spatial frequencies above a certain critical frequency, thereby fulfilling the above-mentioned boundary conditions. The determined point spread functions were subsequently used by the novel Transconvolution algorithm to match different PET/CT systems onto the virtual PET system. Finally, the theoretically elaborated Transconvolution method was validated transforming phantom images acquired on two different PET systems to nearly identical data sets, as they would be imaged by the virtual PET system. Results: The proposed Transconvolution method matched different PET/CT-systems for an improved and reproducible determination of a normalized activity concentration. The highest difference in measured activity concentration between the two different PET systems of 18.2% was found in spheres of 2 ml volume. Transconvolution reduced this difference down to 1.6%. In addition to reestablishing comparability the new method with its parameterization of point spread functions allowed a full characterization of imaging properties of the examined tomographs. Conclusions: By matching different tomographs to a virtual standardized imaging system, Transconvolution opens a new comprehensive method for cross calibration in quantitative PET imaging. The use of a virtual PET system restores comparability between data sets from different PET systems by exerting a common, reproducible, and defined partial volume effect.

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

International Nuclear Information System (INIS)

Song, In Young; Yi, Jeong Geun; Park, Jeong Hee; Lee, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

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

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

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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.

Therapeutic rigid bronchoscopy at a tertiary care center in North India: Initial experience and systematic review of Indian literature

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Karan Madan

2014-01-01

Full Text Available Background and Aim: Rigid bronchoscopy is often an indispensable procedure in the therapeutic management of a wide variety of tracheobronchial disorders. However, it is performed at only a few centers in adult patients in India. Herein, we report our initial 1-year experience with this procedure. Materials and Methods: A prospective observational study on the indications, outcomes, and safety of various rigid bronchoscopy procedures performed between November 2009 and October 2010. Improvement in dyspnea, cough, and the overall quality of life was recorded on a visual analog scale from 0 to 100 mm. A systematic review of PubMed was performed to identify studies reporting the use of rigid bronchoscopy from India. Results: Thirty-eight rigid bronchoscopies (50 procedures were performed in 19 patients during the study period. The commonest indication was benign tracheal stenosis followed by central airway tumor, and the procedures performed were rigid bronchoplasty, tumor debulking, and stent placement. The median procedure duration was 45 (range, 30-65 min. There was significant improvement in quality of life associated with therapeutic rigid bronchoscopy. Minor procedural complications were encountered in 18 bronchoscopies, and there was no procedural mortality. The systematic review identified 15 studies, all on the role of rigid bronchoscopy in foreign body removal. Conclusions: Rigid bronchoscopy is a safe and effective modality for treatment of a variety of tracheobronchial disorders. There is a dire need of rigid bronchoscopy training at teaching hospitals in India.

The comparison of CT virtual colonoscopy with video colonoscopy (the detection of simulated polyps in pig colon)

International Nuclear Information System (INIS)

Tang Wen; Gong Jianping; Gao Zhixin; Lu Zhian

2000-01-01

Objective: To assess the value of CT virtual colonoscopy for the detection of simulated polyps in pig colon. Methods: Injecting the smelted wax under the mucosa to simulate the polyps in pig colon, then detected by video colonoscopy and scanned by helical CT. The images were obtained with collimation 3 mm, 5 mm, 10 mm and with the table pitch 1 and 2. All images were reconstructed at 1 mm intervals. Results: The shapes were depicted as follows: those greater than 10 mm in diameter polyps were clearly depicted. 5-9 mm in diameter polyps were faintly depicted. Those smaller than 5 mm in diameter were depicted difficulty. The details depicted: polyps larger than 10 mm in diameter and 5-9 mm in diameter were clearly depicted and that smaller than 5 mm in diameter were depicted difficulty. The images quality lowered with the increasing collimation and pitch. Conclusion: CT virtual colonoscopy is a non-invasive diagnostic technique. It can show the inner wall of colon as same as video colonoscopy does, and is a good alternative in clinical application

The value of conventional tomography and CT in the diagnosis of bronchial tumors

International Nuclear Information System (INIS)

Mayr, B.; Ingrisch, H.; Haeussinger, K.; Sunder-Plassmann, L.; Huber, R.

1988-01-01

66 patients with suspected bronchial tumors were examined by conventional tomography and by CT. The results were evaluated separately by two radiologists (A and B). All diagnoses were confirmed by bronchoscopy or surgery. In evaluating individual bronchi, conventional tomography had a sensitivity of 88% (A) or 87% (B) and a specificity of 97% (A) or 95% (B); CT had a sensitivity of 95% (A and B) and a specificity of 99% (A and B). If CT is available, our experience indicates that conventional tomography is no longer indicated. (orig.) [de

Virtual colonoscopy with electron beam CT: correlation with barium enema, colonoscopy and pathology

International Nuclear Information System (INIS)

Hong, Hye Suk; Kim, Min Jung; Chung, Jae Joon; Kim, Myeong Jin; Lee, Jong Tae; Yoo, Hyung Sik

1998-01-01

To perform virtual colonoscopy using electron beam tomography(EBT) in patients in whom a colonic mass was present, and to compare the results with those obtained using barium enema, colonoscopy and gross pathologic specimens. Materials and Methods : Ten patients in whom colonic masses were diagnosed by either barium enema or colonoscopy were involved in this study. There were nine cases of adenocarcinoma and one of tubulovillous adenoma. Using EBT preoperative abdominopelvic CT scans were performed. Axial scans were then three-dimensionally reconstructed to produce virtual colonoscopic images and were compared with barium enema, colonoscopy and gross pathologic specimens. Virtual colonoscopic images of the masses were classified as either 1)polyploid, 2)sessile,3)fungating, or 4)annular constrictive. We also determined whether ulcers were present within the lesions and whether there was obstruction. Results : After virtual colonoscopy, two lesions were classified as polyploid, one as sessile, five as fungating and two as annular constrictive. Virtual colonoscopic images showed good correlation with the findings of barium enema, colonoscopy and gross pathologic specimens. Three of six ulcerative lesions were observed on colonoscopy; in seven adenocarcinomas with partial or total luminal obstruction, virtual colonoscopy visualized the colon beyond the obstructed sites. In one case, barium contrast failed to pass through the obstructed portion and in six cases, the colonoscope similarly failed. Conclusion : Virtual colonoscopies correlated well with barium enema, colonoscopy and gross pathologic specimens. They provide three dimensional images of colonic masses and are helpful for the evaluation of obstructive lesions

Post-bronchoscopy pneumonia in patients suffering from lung cancer: Development and validation of a risk prediction score.

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Takiguchi, Hiroto; Hayama, Naoki; Oguma, Tsuyoshi; Harada, Kazuki; Sato, Masako; Horio, Yukihiro; Tanaka, Jun; Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Takihara, Takahisa; Niimi, Kyoko; Nakagawa, Tomoki; Masuda, Ryota; Aoki, Takuya; Urano, Tetsuya; Iwazaki, Masayuki; Asano, Koichiro

2017-05-01

The incidence, risk factors, and consequences of pneumonia after flexible bronchoscopy in patients with lung cancer have not been studied in detail. We retrospectively analyzed the data from 237 patients with lung cancer who underwent diagnostic bronchoscopy between April 2012 and July 2013 (derivation sample) and 241 patients diagnosed between August 2013 and July 2014 (validation sample) in a tertiary referral hospital in Japan. A score predictive of post-bronchoscopy pneumonia was developed in the derivation sample and tested in the validation sample. Pneumonia developed after bronchoscopy in 6.3% and 4.1% of patients in the derivation and validation samples, respectively. Patients who developed post-bronchoscopy pneumonia needed to change or cancel their planned cancer therapy more frequently than those without pneumonia (56% vs. 6%, ppneumonia, which we added to develop our predictive score. The incidence of pneumonia associated with scores=0, 1, and ≥2 was 0, 3.7, and 13.4% respectively in the derivation sample (p=0.003), and 0, 2.9, and 9.7% respectively in the validation sample (p=0.016). The incidence of post-bronchoscopy pneumonia in patients with lung cancer was not rare and associated with adverse effects on the clinical course. A simple 3-point predictive score identified patients with lung cancer at high risk of post-bronchoscopy pneumonia prior to the procedure. Copyright © 2017 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Management of airway foreign body using flexible bronchoscopy: Experience with 80 cases during 2011–2013

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Safy Kaddah

2015-01-01

Conclusions: Flexible bronchoscopy is successful in retrieving airway foreign bodies (88.8%. With skilled personnel and perfect equipments, flexible bronchoscopy could be considered as the first choice for the removal of airway foreign body.

Virtual colonoscopy (CT colonography) in the identification of colorectal cancer. A prospective study in symptomatic patients

International Nuclear Information System (INIS)

Regge, D.; Martincich, L.; Gallo, T.; Pollone, M.; Galatola, G.; Secreto, P.; Pera, A.; Rivolta, A.

2000-01-01

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 waranted in larger series of patients, possibly introducing it in screening programs [it

Electromagnetic navigation bronchoscopy: clinical utility in the diagnosis of lung cancer

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Seijo LM

2016-10-01

Full Text Available Luis M Seijo Pulmonary Department, Instituto de Investigación Sanitaria-Fundación Jimenez Díaz-Centro de Investigación Biomedica en Red Enfermedades Respiratorias, Madrid, Spain Abstract: Electromagnetic navigation bronchoscopy (ENB is one of several technological advances which have broadened the indications for bronchoscopy in the diagnostic workup of lung cancer. The technique facilitates bronchoscopic sampling of peripheral pulmonary nodules as well as mediastinal lymph nodes, although wide availability and expertise in endobronchial ultrasonography has limited its application in routine clinical practice to the former. ENB in this setting is quite versatile and may be considered an established alternative to more invasive techniques, especially in selected patients with underlying pulmonary disease or comorbidities at high risk for complications from computer topography-guided fine needle aspiration or surgical resection. Nodule sampling may be performed with a variety of instruments, including forceps, cytology brushes, and transbronchial needles. Although samples are generally small, they are often suitable for molecular analysis. Keywords: lung cancer, ENB, electromagnetic navigation, bronchoscopy, diagnosis, pulmonary nodule

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

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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

Removal of metallic tracheobronchial stents in lung transplantation with flexible bronchoscopy

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Fruchter Oren

2010-09-01

Full Text Available Abstract Background Airway complications are among the most challenging problems after lung transplantation, and Self-Expandable Metallic Stents (SEMS are used to treat airway complications such as stenosis or malacia at the bronchial anastomosis sites. Several transplantation centers are reluctant to use SEMS since their removal is sometimes needed and usually requires the use of rigid bronchoscopy under general anesthesia. The objective of the current report is to describe our experience in SEMS retrieval by flexible bronchoscopy under conscious sedation. Methods A retrospective review was done of patients requiring tracheobronchial stent placement after lung transplantation in which the SEMS had to be removed. The retrieval procedure was done by flexible bronchoscopy on a day-care ambulatory basis. Results Between January 2004 and January 2010, out of 305 lung transplantation patients, 24 (7.8% underwent SEMS placement. Indications included bronchial stenosis in 20 and bronchomalacia in 4. In six patients (25% the SEMS had to be removed due to excessive granulation tissue formation and stent obstruction. The average time from SEMS placement to retrieval was 30 months (range 16-48 months. The stent was completely removed in five patients and partially removed in one patient; no major complications were encountered, and all patients were discharged within 3 hours of the procedure. In all procedures, new SEMS was successfully re-inserted thereafter. Conclusions The retrieval of SEMS in patients that underwent lung transplantation can be effectively and safely done under conscious sedation using flexible bronchoscopy on a day-care basis, this observation should encourage increasing usage of SEMS in highly selected patients.

Virtual computed tomography cystoscopy in bladder pathologies

International Nuclear Information System (INIS)

Arslan, Halil; Ceylan, Kadir; Harman, Mustafa; Yilmaz, Yuksel; Temizoz, Osman; Can, Saban

2006-01-01

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)

Reliable and Valid Assessment of Clinical Bronchoscopy Performance

DEFF Research Database (Denmark)

Konge, Lars; Larsen, Klaus Richter; Clementsen, Paul

2012-01-01

: The interrater reliability was high, with Cronbach's a = 0.86. Assessment of 3 bronchoscopies by a single rater had a generalizability coefficient of 0.84. The correlation between experience and performance was good (Pearson correlation = 0.76). There were significant differences between the groups for all...

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

2015-08-07

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

Dual-Energy CT in Enhancing Subdural Effusions that Masquerade as Subdural Hematomas: Diagnosis with Virtual High-Monochromatic (190-keV) Images.

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Bodanapally, U K; Dreizin, D; Issa, G; Archer-Arroyo, K L; Sudini, K; Fleiter, T R

2017-10-01

Extravasation of iodinated contrast into subdural space following contrast-enhanced radiographic studies results in hyperdense subdural effusions, which can be mistaken as acute subdural hematomas on follow-up noncontrast head CTs. Our aim was to identify the factors associated with contrast-enhancing subdural effusion, characterize diffusion and washout kinetics of iodine in enhancing subdural effusion, and assess the utility of dual-energy CT in differentiating enhancing subdural effusion from subdural hematoma. We retrospectively analyzed follow-up head dual-energy CT studies in 423 patients with polytrauma who had undergone contrast-enhanced whole-body CT. Twenty-four patients with enhancing subdural effusion composed the study group, and 24 randomly selected patients with subdural hematoma were enrolled in the comparison group. Postprocessing with syngo.via was performed to determine the diffusion and washout kinetics of iodine. The sensitivity and specificity of dual-energy CT for the diagnosis of enhancing subdural effusion were determined with 120-kV, virtual monochromatic energy (190-keV) and virtual noncontrast images. Patients with enhancing subdural effusion were significantly older (mean, 69 years; 95% CI, 60-78 years; P subdural effusions was reached within the first 8 hours of contrast administration with a mean of 0.98 mg/mL (95% CI, 0.81-1.13 mg/mL), and complete washout was achieved at 38 hours. For the presence of a hyperdense subdural collection on 120-kV images with a loss of hyperattenuation on 190-keV and virtual noncontrast images, when considered as a true-positive for enhancing subdural effusion, the sensitivity was 100% (95% CI, 85.75%-100%) and the specificity was 91.67% (95% CI, 73%-99%). Dual-energy CT has a high sensitivity and specificity in differentiating enhancing subdural effusion from subdural hematoma. Hence, dual-energy CT has a potential to obviate follow-up studies. © 2017 by American Journal of Neuroradiology.

Experimental study of virtual colonoscopy of simulated mass lesions in pig colon: comparison of CT and MR techniques

International Nuclear Information System (INIS)

Yang Xiujun; He Zhiyan; Tao Yonghao; Miao Jingtao; Chen Yuanjiong; Hu Yuansheng; Wang Linchuan

2000-01-01

Objective: To probe into the technique and diagnostic value of MR virtual colonoscopy (MRVC) compared with CT virtual colonoscopy (CTVC) and colonoscopy. Methods: Two approximately 25-cm-long-sections of fresh pit colon in vitro had 20 mass lesions created ranging from 3 mm to 12 mm in diameter. MR scanning, as well as CT scanning of the water- or air-insufflated colon was performed, and CT data were obtained with collimation of 3 mm at a pitch of 1.0 and reconstruction intervals of 1.5 mm. MRI data were acquired with the same matrix and reformatting slab, and with heavily T 2 -weighted fast spin-echo pulse sequences. Post processed image sets were performed by the same experienced doctor on a workstation using navigator software based on CT or MRI source imaging data. One section was also underwent electron colonoscopy. Results: MRVC and CTVC displayed colon morphology in a manner similar to colonoscopy. The sensitivity of MRVC and CTVC were all 100%, and the accuracy was 71.4% for MRVC and 100% for CTVC. With the combined analysis of the four-in-one multi-view images, they accurately demonstrated the site and size of lesions and distinguished the lesions from the artifacts such as small air bubbles, and the accuracy of MRVC was improved up to 100%. CTVC was better than MRVC (P<0.05), but both were inferior to colonoscopy in depicting mucosal details of the colon and lesions (P < 0.025). Conclusion: Virtual colonoscopy (CTVC or MRVC, the former appears better) provided noninvasive endoscope-like display of the colon, and permitted identification of colonic mass lesions as small as 3 mm in diameter, the diagnostic accuracy could be improved by combining with source images and other reformations

High-risk respiratory patients' experiences of bronchoscopy with conscious sedation and analgesia: A qualitative study.

Science.gov (United States)

Saxon, Catherine; Fulbrook, Paul; Fong, Kwun M; Ski, Chantal F

2017-10-20

To understand the experiences of high-risk respiratory patients undergoing bronchoscopy with conscious sedation. Due to possible complications, high-risk respiratory patients are usually given smaller, cautious doses of sedation and analgesia for bronchoscopy. Described as "conscious sedation," this facilitates depression of the patient's consciousness without causing respiratory compromise. Previously, studies have investigated patient experience using quantitative methods. This is the first study that has explored the patient experience during bronchoscopy from a qualitative perspective. Qualitative, phenomenological approach as described by Van Manen. The setting was an endoscopy unit within an Australian tertiary hospital. Unstructured interviews were conducted with 13 patients with chronic obstructive pulmonary disease who underwent day-case bronchoscopy. All participants received conscious sedation. They were interviewed twice, within a week, postprocedure. Interviews were transcribed verbatim and analysed using Van Manen's interpretive approach. Participants had varying experiences. Five themes emerged from the analysis: Frustration and fear; Comfort and safety; Choking and coughing; Being aware; and Consequences. Whilst not all participants experienced procedural awareness or remembered it, for those who did it was a significant event. Overall, experiences were found to be negative; however, participants accepted and tolerated them, perceiving them as necessary to obtain a diagnostic result. The findings demonstrate that often patients are aware during the procedure and their experience may be uncomfortable and distressing. These findings have implications for patient preparation pre- and post-bronchoscopy in terms of what they might expect, and to discuss what has happened after the procedure. Some practices of the bronchoscopy team during the procedure may need modification. For example, in anticipation of the possibility that the patient may be aware

[Application of bispectral index monitoring in sedation and analgesia for flexible bronchoscopy].

Science.gov (United States)

Fang, S R; Liu, Y J; Su, N J; Shu, Y; Gu, W

2017-12-12

Objective: To investigate the feasibility of using bispectral index monitoring in sedation and analgesia for bronchoscopy. Methods: Totally 285 patients admitted to the Respiratory Medicine Department of Nanjing First Hospital for bronchoscopy between June 2016 and December 2016 were assigned, according to their own wishes, into a conscious sedation group (171 cases receiving local anesthesia and conscious sedation, 89 males, 82 females, mean age 59±10 years) and a control group (114 cases undergoing local anesthesia, 59 males, 55 females, average age 61±12 years). The 2 groups were compared in terms of operation time, blood pressure, heart rate and other indicators during bronchoscopy including incidence of adverse events, memory of the procedure, willingness to be re-examined, safety of sedation and analgesia for bronchoscopy under bispectral index monitoring, and patient satisfaction in the postoperative follow-up. Results: The conscious sedation group and the control group had no difference in age and sex ratio( P >0.05). Compared with the patients in the control group(operation time 16±5 min and systolic blood pressure 153±21 mmHg, 1 mmHg=0.133 kPa), those in the conscious sedation group had a shorter operation time(14±5 min) and a lower systolic blood pressure(144±22 mmHg), with statistically significant difference ( P sedation group and 92±12 mmHg and 87±14 times/min in the control group, P >0.05). Adverse events, overall intraoperative cough and bleeding were found to be significantly reduced in the conscious sedation group (27%, 4% and 13% and 60%, 13% and 35% in the control group, P sedation group, and 14% in the control group, P =0.72). Patient satisfaction and willingness to be re-examined were markedly higher in the conscious sedation group (97%) than in the controls (4%, P sedation and analgesia for bronchoscopy and has higher patient satisfaction, suggesting that it is a potential tool for use in clinical practice.

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)

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. PMID:23823503

Dual-source virtual non-contrast CT of the head: a preliminary study

International Nuclear Information System (INIS)

Huang Wei; Xu Yiming; Shao Jin

2011-01-01

Objective: To investigate image quality and clinical value of dual-source dual energy virtual non-contrast (VNC) CT of the head. Methods: Sixty-two patients suspected of cerebrovascular diseases underwent conventional non-contrast (CNC) CT and dual energy CTA examination of the head with dual-source CT. Virtual non-contrast images were reconstructed using dual energy software. The CT values of gray matter, white matter, cerebrospinal fluid, hyperdense hemorrhagic lesion and hypodense ischemic lesion were compared between CNC and VNC images. A four-score scale was used to assess image quality subjectively. Image noise, radiation dosage and detection rate were compared between CNC and VNC images. Paired t test, Wilcoxon signed ranks test and Chi-square test (McNemar test and Kappa test) were used. Results: The CT value on CNC and VNC images, were (43.3±1.5) and (33.2±1.3) HU for gray matter (t=46.98, P 0.05, Kappa = 1.000) at per-patient level. Twenty-two patients with hypodense ischemic lesions were found on VNC images with one false positive case and two false negative cases. The sensitivity, specificity, positive predictive value and negative predictive value were 91.3% (21/23), 97.4% (38/39), 95.5% (21/22) and 95.0% (38/40) respectively. No statistical difference was found in detecting hypodense lesions between VNC and CNC images (χ 2 = 0.00, P>0.05, Kappa = 0.895). In per-lesion analysis, 53 hemorrhage lesions were found on VNC images with false negative results of four lesions and no false positive result. The sensitivity, specificity, positive predictive value and negative predictive value were 93.0% (53/57). 100.0% (38/38), 100.0% (53/.53) and 90.5% (38/42) respectively. There was no significant difference in detection rate of hyperdense lesion between VNC and CNC images (χ 2 = 2.25, P>0.05, Kappa = 0.914). Thirty-eight hypodense lesions were found on VNC images with 2 false positive lesions and 13 false negative lesions. The sensitivity, specificity

Fiberoptic bronchoscopy in the diagnosis and therapeutic decision for respiratory infections in hematological febrile neutropenic patients

Directory of Open Access Journals (Sweden)

Luiza Bento

2014-06-01

Full Text Available Background: Febrile neutropenia is a common complication in patients undergoing chemotherapy or hematopoietic Stem Cell Transplantation (HSCT. Flexible fiberoptic bronchoscopy has been used to aid in the diagnosis of pulmonary diseases. However, there is no consensus regarding the benefit of the exam in establishing diagnosis and in changing the treatment of lung disease in this context. Previous retrospective studies, quite heterogeneous and with non-HIV immunocompromised patients, showed that the yield of fiberoptic bronchoscopy in establishing etiology ranges from 13% to 81%, and in changing therapy, from 5% to 51%. Aim: To evaluate the efficiency of Fiberoptic bronchoscopy and the procedure-related risk for neutropenic patients with hematologic malignancy. Methods: This retrospective cross-sectional study analyzed the medical records of patients with hematologic malignancy with febrile neutropenia who had undergone diagnostic fiberoptic bronchoscopy between January 2011 and December 2012 at the Hospital de Clínicas de Porto Alegre. Results: A total of 45 patients were included: 18 (36% tested positive for bronchoalveolar lavage, with change in therapeutic management occurring for 95% of them. The procedure-related risk was 2.2%, with one patient showing desaturation immediately after the procedure. Conclusion:  Despite the limited number of patients, our findings indicate that fiberoptic bronchoscopy in neutropenic patients is safe, and the results are similar to those previously reported.

Complete subglottic tracheal stenosis managed with rigid bronchoscopy and T-tube placement

Directory of Open Access Journals (Sweden)

Kuruswamy Thurai Prasad

2016-01-01

Full Text Available Surgery is the preferred treatment modality for benign tracheal stenosis. Interventional bronchoscopy is used as a bridge to surgery or in instances when surgery is not feasible or has failed. Stenosis in the subglottic trachea is particularly a treatment challenge, in view of its proximity to the vocal cords. Herein, we describe a patient with complete tracheal stenosis in the subglottic region, which developed after prolonged intubation and mechanical ventilation. The patient developed recurrent stenosis despite multiple surgical and endoscopic procedures. We were able to manage the patient successfully with rigid bronchoscopy and Montgomery T-tube placement.

Pulmonary manifestations in HIV patients: The role of chest films, CT and HRCT

International Nuclear Information System (INIS)

Kauczor, H.U.; Schnuetgen, M.; Fischer, B.; Schwickert, H.C.; Haertel, S.; Schadmand-Fischer, S.; Gerken, G.; Schweden, F.

1995-01-01

64 HIV patients were examined prospectively. 15 had no respiratory symptoms (group I), 30 had non-specific respiratory symptoms (group II), 19 complained of dyspnoea (group III). Chest radiographs and CT were performed within a week. In patients with positive findings, bronchoscopy was carried out with bacteriological and histological examinations. In group I, 13% of chest radiographs and 40% of CT's showed infiltrative changes. In group II, the figures were 27% and 57% respectively. In group III, abnormalities were found in all cases by both examinations. (orig./MG) [de

Virtual-reality displaying of workpiece by reverse modeling

International Nuclear Information System (INIS)

Wu Huimin; Zhang Li; Chen Zhiqiang; Zhao Ziran

2006-01-01

The authors first propose a suit of CT data processing system: virtual-reality-based testing of workpiece by Reverse Modeling. For reverse modeling module, the authors propose two solutions: integrating Medical CT Modeling software and using VTK library to develop independently. Then, the authors analyze the required functions and characteristics of CT-based Reverse Modeling module, and the key technologies for developing. For virtual-reality module, the authors study characteristics of CT data and the needs of CT users, and describe the required functions and key techniques as for virtual reality displaying module. The authors still analyze the problems and prospective of development. (authors)

Comparative study between computed tomography and bronchoscopy in the diagnosis of lung cancer

International Nuclear Information System (INIS)

Oliveira, Christopher; Saraiva, Antonio

2010-01-01

Objective: to analyze the role of computed tomography and bronchoscopy in the diagnosis of lung cancer, evaluating the effectiveness of these techniques in the presence of this disease. Parameters such as age, gender, smoking habits, histological types, staging and treatment were also analyzed. Materials and methods: the sample of the present study included 70 patients assisted at the Department of Pneumology of Hospital Distrital da Figueira da Foz, Coimbra, Portugal, who were submitted to both diagnostic methods, namely, computed tomography and bronchoscopy, to confirm the presence or the absence of lung cancer. Results: thirty-seven patients (23 men and 14 women) were diagnosed with lung cancer. Histologically 40.54% were adenocarcinoma, followed by squamous carcinoma (32.43% cases) and small-cell lung cancer (18.92%). Staging showed 6.70% stage IB disease, 23.30% stage IIIA and 36.70% stage IIIB, and 33.30% stage IV. Chemotherapy alone was the first treatment of choice for 75.7% of patients. Bronchoscopy sensitivity was 83.8%, specificity 81.8%, and accuracy 82.8%. Computed tomography sensitivity was 81.1%, specificity 63.6%, and accuracy 72.8%. Conclusion: bronchoscopy results corroborated the relevance of the method in the diagnosis of lung cancer, considering its dependence on the anatomopathological study of tissue or cells obtained through different biopsy techniques. Computed tomography presented good sensitivity (81.1%), however the specificity of only 63.6% is related to the rate of false-positive results (36.4%). (author)

Comparative study between computed tomography and bronchoscopy in the diagnosis of lung cancer

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Christopher; Saraiva, Antonio, E-mail: asaraiva@estescoimbra.p [Escola Superior de Tecnologia da Saude de Coimbra (ESTeSC), Coimbra (Portugal)

2010-07-15

Objective: to analyze the role of computed tomography and bronchoscopy in the diagnosis of lung cancer, evaluating the effectiveness of these techniques in the presence of this disease. Parameters such as age, gender, smoking habits, histological types, staging and treatment were also analyzed. Materials and methods: the sample of the present study included 70 patients assisted at the Department of Pneumology of Hospital Distrital da Figueira da Foz, Coimbra, Portugal, who were submitted to both diagnostic methods, namely, computed tomography and bronchoscopy, to confirm the presence or the absence of lung cancer. Results: thirty-seven patients (23 men and 14 women) were diagnosed with lung cancer. Histologically 40.54% were adenocarcinoma, followed by squamous carcinoma (32.43% cases) and small-cell lung cancer (18.92%). Staging showed 6.70% stage IB disease, 23.30% stage IIIA and 36.70% stage IIIB, and 33.30% stage IV. Chemotherapy alone was the first treatment of choice for 75.7% of patients. Bronchoscopy sensitivity was 83.8%, specificity 81.8%, and accuracy 82.8%. Computed tomography sensitivity was 81.1%, specificity 63.6%, and accuracy 72.8%. Conclusion: bronchoscopy results corroborated the relevance of the method in the diagnosis of lung cancer, considering its dependence on the anatomopathological study of tissue or cells obtained through different biopsy techniques. Computed tomography presented good sensitivity (81.1%), however the specificity of only 63.6% is related to the rate of false-positive results (36.4%). (author)

Music does not alter anxiety in patients with suspected lung cancer undergoing bronchoscopy

DEFF Research Database (Denmark)

Jeppesen, Elisabeth; Pedersen, Carsten M; Larsen, Klaus R

2016-01-01

BACKGROUND: The use of music to relieve anxiety has been examined in various studies, but the results are inconclusive. METHODS: From April to October 2015, 160 patients undergoing examination of pulmonary nodules were randomly assigned to MusiCure or no music. MusiCure was administered through e...... earplugs to ensure blinding of the staff and was played from admission to the operating theatre to the end of the bronchoscopy. Spielberger's State-Trait Anxiety Inventory (STAI) was administered on admission, immediately before bronchoscopy, and on discharge. Secondary outcomes were p...

CT virtual intravascular endoscopy assessment of coronary artery plaques: A preliminary study

International Nuclear Information System (INIS)

Sun Zhonghua; Dimpudus, Franky Jacobus; Nugroho, Johanes; Adipranoto, Jeffrey Daniel

2010-01-01

Purpose: The purpose of this study was to investigate the potential value of CT virtual intravascular endoscopy (VIE) in the visualization and assessment of coronary plaques in patients suspected of coronary artery disease. Materials and methods: 20 (13 men, 7 women, mean age 54 years) consecutive patients with suspected coronary artery disease undergoing 64-slice CT angiography were included in the study. Four main coronary artery branches were assessed with regard to the presence of coronary plaques based on 2D axial, multiplanar reformation, 3D volume rendering and VIE visualizations. The coronary plaques were characterized into calcified, noncalcified and mixed plaques. The intraluminal appearances of these coronary plaques were demonstrated with VIE images and correlated with 2D and 3D images to determine the diagnostic value of VIE for the assessment of the plaques. Results: VIE was able to identify and demonstrate the intraluminal appearances of coronary plaques in 18 patients involving 32 coronary artery branches which were shown as an irregularly intraluminal protruding sign in extensively calcified plaques and smooth protruding appearance in noncalcified or focally calcified plaques. An irregular intraluminal appearance was also noticed in the presence of mixed plaques due to variable components with different CT attenuations contained within the plaques. VIE accurately confirmed the degree of coronary stenosis or occlusion despite the presence of heavy calcification. Conclusion: VIE could be used as a complementary tool to conventional CT visualizations for the analysis of luminal changes and assessment of disease extent caused by the coronary plaques.

Quantifying metal artefact reduction using virtual monochromatic dual-layer detector spectral CT imaging in unilateral and bilateral total hip prostheses

Energy Technology Data Exchange (ETDEWEB)

Wellenberg, R.H.H., E-mail: r.h.wellenberg@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Boomsma, M.F., E-mail: m.f.boomsma@isala.nl [Department of Radiology, Isala, Zwolle (Netherlands); Osch, J.A.C. van, E-mail: j.a.c.van.osch@isala.nl [Department of Radiology, Isala, Zwolle (Netherlands); Vlassenbroek, A., E-mail: alain.vlassenbroek@philips.com [Philips Medical Systems, Brussels (Belgium); Milles, J., E-mail: julien.milles@philips.com [Philips Medical Systems, Eindhoven (Netherlands); Edens, M.A., E-mail: m.a.edens@isala.nl [Department of Innovation and Science, Isala, Zwolle (Netherlands); Streekstra, G.J., E-mail: g.j.streekstra@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Slump, C.H., E-mail: c.h.slump@utwente.nl [MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede (Netherlands); Maas, M., E-mail: m.maas@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

2017-03-15

Highlights: • Dual-layer detector CT reduces metal artefacts at high monochromatic energies (keV). • 130 keV images were optimal based on quantitative analysis on CNRs. • Optimal keVs varied from 74 to 150 keV for different hip prostheses configurations. • The Titanium alloy resulted in less severe artefacts compared to the Cobalt alloy. • Severe metal artefacts, caused by extensive photon-starvation, were not reduced. - Abstract: Purpose: To quantify the impact of prosthesis material and design on the reduction of metal artefacts in total hip arthroplasties using virtual monochromatic dual-layer detector Spectral CT imaging. Methods: The water-filled total hip arthroplasty phantom was scanned on a novel 128-slice Philips IQon dual-layer detector Spectral CT scanner at 120-kVp and 140-kVp at a standard computed tomography dose index of 20.0 mGy. Several unilateral and bilateral hip prostheses consisting of different metal alloys were inserted and combined which were surrounded by 18 hydroxyapatite calcium carbonate pellets representing bone. Images were reconstructed with iterative reconstruction and analysed at monochromatic energies ranging from 40 to 200 keV. CT numbers in Hounsfield Units (HU), noise measured as the standard deviation in HU, signal-to-noise-ratios (SNRs) and contrast-to-noise-ratios (CNRs) were analysed within fixed regions-of-interests placed in and around the pellets. Results: In 70 and 74 keV virtual monochromatic images the CT numbers of the pellets were similar to 120-kVp and 140-kVp polychromatic results, therefore serving as reference. A separation into three categories of metal artefacts was made (no, mild/moderate and severe) where pellets were categorized based on HU deviations. At high keV values overall image contrast was reduced. For mild/moderate artefacts, the highest average CNRs were attained with virtual monochromatic 130 keV images, acquired at 140-kVp. Severe metal artefacts were not reduced. In 130 keV images

Case report: Inhaled foreign body mismanaged as TB, finally removed using a rigid bronchoscopy after 6 years of impaction

Directory of Open Access Journals (Sweden)

Justin Rubena Lumaya

2016-02-01

Full Text Available Foreign body aspiration is an important cause of mortality in children aged less than three years. Foreign body (FB inhalation can pose diagnostic and therapeutic challenges, especially in longstanding cases and complications such as recurrent pneumonia, lung collapse and lung abscess may develop. We report a case of an 11-year old boy with foreign body impacted in his bronchus for six years, which was mistakenly managed as pulmonary tuberculosis. Radiological evidence confirmed the diagnosis and a rigid bronchoscopy was used to remove the metallic foreign body. The standard of care for the management of a FB in a bronchus is a rigid bronchoscopy; however flexible bronchoscopy can be used, especially in adults. A thorough history with radiological evidence are essential and sometimes, followed by a diagnostic bronchoscopy.

Virtual Colonoscopy Screening With Ultra Low-Dose CT and Less-Stressful Bowel Preparation: A Computer Simulation Study

Science.gov (United States)

Wang, Jing; Wang, Su; Li, Lihong; Fan, Yi; Lu, Hongbing; Liang, Zhengrong

2008-10-01

Computed tomography colonography (CTC) or CT-based virtual colonoscopy (VC) is an emerging tool for detection of colonic polyps. Compared to the conventional fiber-optic colonoscopy, VC has demonstrated the potential to become a mass screening modality in terms of safety, cost, and patient compliance. However, current CTC delivers excessive X-ray radiation to the patient during data acquisition. The radiation is a major concern for screening application of CTC. In this work, we performed a simulation study to demonstrate a possible ultra low-dose CT technique for VC. The ultra low-dose abdominal CT images were simulated by adding noise to the sinograms of the patient CTC images acquired with normal dose scans at 100 mA s levels. The simulated noisy sinogram or projection data were first processed by a Karhunen-Loeve domain penalized weighted least-squares (KL-PWLS) restoration method and then reconstructed by a filtered backprojection algorithm for the ultra low-dose CT images. The patient-specific virtual colon lumen was constructed and navigated by a VC system after electronic colon cleansing of the orally-tagged residue stool and fluid. By the KL-PWLS noise reduction, the colon lumen can successfully be constructed and the colonic polyp can be detected in an ultra low-dose level below 50 mA s. Polyp detection can be found more easily by the KL-PWLS noise reduction compared to the results using the conventional noise filters, such as Hanning filter. These promising results indicate the feasibility of an ultra low-dose CTC pipeline for colon screening with less-stressful bowel preparation by fecal tagging with oral contrast.

μCT of ex-vivo stained mouse hearts and embryos enables a precise match between 3D virtual histology, classical histology and immunochemistry

Science.gov (United States)

Larsson, Emanuel; Martin, Sabine; Lazzarini, Marcio; Tromba, Giuliana; Missbach-Guentner, Jeannine; Pinkert-Leetsch, Diana; Katschinski, Dörthe M.; Alves, Frauke

2017-01-01

The small size of the adult and developing mouse heart poses a great challenge for imaging in preclinical research. The aim of the study was to establish a phosphotungstic acid (PTA) ex-vivo staining approach that efficiently enhances the x-ray attenuation of soft-tissue to allow high resolution 3D visualization of mouse hearts by synchrotron radiation based μCT (SRμCT) and classical μCT. We demonstrate that SRμCT of PTA stained mouse hearts ex-vivo allows imaging of the cardiac atrium, ventricles, myocardium especially its fibre structure and vessel walls in great detail and furthermore enables the depiction of growth and anatomical changes during distinct developmental stages of hearts in mouse embryos. Our x-ray based virtual histology approach is not limited to SRμCT as it does not require monochromatic and/or coherent x-ray sources and even more importantly can be combined with conventional histological procedures. Furthermore, it permits volumetric measurements as we show for the assessment of the plaque volumes in the aortic valve region of mice from an ApoE-/- mouse model. Subsequent, Masson-Goldner trichrome staining of paraffin sections of PTA stained samples revealed intact collagen and muscle fibres and positive staining of CD31 on endothelial cells by immunohistochemistry illustrates that our approach does not prevent immunochemistry analysis. The feasibility to scan hearts already embedded in paraffin ensured a 100% correlation between virtual cut sections of the CT data sets and histological heart sections of the same sample and may allow in future guiding the cutting process to specific regions of interest. In summary, since our CT based virtual histology approach is a powerful tool for the 3D depiction of morphological alterations in hearts and embryos in high resolution and can be combined with classical histological analysis it may be used in preclinical research to unravel structural alterations of various heart diseases. PMID:28178293

Blunt traumatic rupture of a mainstem bronchus: spiral CT demonstration of the ''fallen lung'' sign

International Nuclear Information System (INIS)

Wintermark, M.; Schnyder, P.; Wicky, S.

2001-01-01

Tracheo-bronchial injuries occur in less than 1 % of blunt chest trauma patients. Indirect signs, such as pneumomediastinum, pneumothorax, and/or subcutaneous emphysema, are revealed on admission plain films and chest CT survey. In most instances, however, tracheo-bronchoscopy is mandatory in assessing the definite diagnosis of tracheo-bronchial lesion. Occasionally, an abnormal course of a mainstem bronchus or a ''fallen lung'' sign, featuring a collapsed lung in a dependent position, hanging on the hilum only by its vascular attachments, may allow for CT diagnosis of a blunt traumatic bronchial injury. (orig.)

Web-based versus traditional lecture: are they equally effective as a flexible bronchoscopy teaching method?

OpenAIRE

Sterse Mata, Caio Augusto [UNIFESP; Ota, Luiz Hirotoshi [UNIFESP; Suzuki, Iunis [UNIFESP; Telles, Adriana [UNIFESP; Miotto, Andre [UNIFESP; Leao, Luiz Eduardo Villaca [UNIFESP

2012-01-01

This study compares the traditional live lecture to a web-based approach in the teaching of bronchoscopy and evaluates the positive and negative aspects of both methods. We developed a web-based bronchoscopy curriculum, which integrates texts, images and animations. It was applied to first-year interns, who were later administered a multiple-choice test. Another group of eight first-year interns received the traditional teaching method and the same test. the two groups were compared using the...

Reliability of implant placement after virtual planning of implant positions using cone beam CT data and surgical (guide) templates.

Science.gov (United States)

Nickenig, Hans-Joachim; Eitner, Stephan

2007-01-01

We assessed the reliability of implant placement after virtual planning of implant positions using cone-beam CT data and surgical guide templates. A total of 102 patients (250 implants, 55.4% mandibular; mean patient age, 40.4 years) who had undergone implant treatment therapy in an armed forces dental clinic (Cologne, Germany) between July 1, 2005 and December 1, 2005. They were treated with a system that allows transfer of virtual planning to surgical guide templates. Only in eight cases the surgical guides were not used because a delayed implant placement was necessary. In four posterior mandibular cases, handling was limited because of reduced interocclusal distance, requiring 50% shortening of the drill guides. The predictability of implant size was high: only one implant was changed to a smaller diameter (because of insufficient bone). In all cases, critical anatomical structures were protected and no complications were detected in postoperative panoramic radiographs. In 58.1% (147) of the 250 implants, a flapless surgery plan was realized. Implant placement after virtual planning of implant positions using cone beam CT data and surgical templates can be reliable for preoperative assessment of implant size, position, and anatomical complications. It is also indicative of cases amenable to flapless surgery.

Scaphoid fracture: Bone marrow edema detected with dual-energy CT virtual non-calcium images and confirmed with MRI

Energy Technology Data Exchange (ETDEWEB)

Dareez, Nazeer M.; Engesland, Eirin; Lindland, Elisabeth S. [Department of Radiology, SSHF Arendal, Arendal (Norway); Dahlslett, Kristine H. [Haukelands Universitetssjukehus, Department of Radiology, Bergen (Norway)

2017-12-15

We aimed to determine whether bone marrow edema (BME) in acute traumatic scaphoid fracture could be demonstrated with dual-energy CT (DECT) using MRI as the gold standard. In recent years, virtual non-calcium (VNCa) images have been used to demonstrate BME in trauma cases, for example, in vertebral compression fractures, hip trauma to detect occult fractures and knee fractures. We present three cases of acute scaphoid trauma. Two patients had subtle or invisible fractures on x-ray and conventional CT images, while DECT VNCa images clearly visualized the BME, which was confirmed by MRI. One patient had negative findings on both VNCa and MRI images. The DECT VNCa algorithm is a promising technique to demonstrate BME in scaphoid fractures, with potential for increasing the diagnostic value of CT in this type of injury. (orig.)

Bronchoscopy for the diagnosis of pulmonary tuberculosis in patients with negative sputum smear microscopy results.

Science.gov (United States)

Jacomelli, Márcia; Silva, Priscila Regina Alves Araújo; Rodrigues, Ascedio Jose; Demarzo, Sergio Eduardo; Seicento, Márcia; Figueiredo, Viviane Rossi

2012-01-01

To evaluate the diagnostic accuracy of bronchoscopy in patients with clinical or radiological suspicion of tuberculosis who were unable to produce sputum or with negative sputum smear microscopy results. A prospective cross-sectional study involving 286 patients under clinical or radiological suspicion of having pulmonary tuberculosis and submitted to bronchoscopy-BAL and transbronchial biopsy (TBB). The BAL specimens were submitted to direct testing and culture for AFB and fungi, whereas the TBB specimens were submitted to histopathological examination. Of the 286 patients studied, 225 (79%) were diagnosed on the basis of bronchoscopic findings, as follows: pulmonary tuberculosis, in 127 (44%); nonspecific chronic inflammation, in 51 (18%); pneumocystis, fungal infections, or nocardiosis, in 20 (7%); bronchiolitis obliterans organizing pneumonia, alveolites, or pneumoconiosis, in 14 (5%); lung or metastatic neoplasms, in 7 (2%); and nontuberculous mycobacterium infections, in 6 (2%). For the diagnosis of tuberculosis, BAL showed a sensitivity and a specificity of 60% and 100%, respectively. Adding the TBB findings significantly increased this sensitivity (to 84%), as did adding the post-bronchoscopy sputum smear microscopy results (total sensitivity, 94%). Minor post-procedure complications occurred in 5.6% of the cases. Bronchoscopy is a reliable method for the diagnosis of pulmonary tuberculosis, with low complication rates. The combination of TBB and BAL increases the sensitivity of the method and facilitates the differential diagnosis with other diseases.

An automatic virtual patient reconstruction from CT-scans for hepatic surgical planning.

Science.gov (United States)

Soler, L; Delingette, H; Malandain, G; Ayache, N; Koehl, C; Clément, J M; Dourthe, O; Marescaux, J

2000-01-01

PROBLEM/BACKGROUND: In order to help hepatic surgical planning we perfected automatic 3D reconstruction of patients from conventional CT-scan, and interactive visualization and virtual resection tools. From a conventional abdominal CT-scan, we have developed several methods allowing the automatic 3D reconstruction of skin, bones, kidneys, lung, liver, hepatic lesions, and vessels. These methods are based on deformable modeling or thresholding algorithms followed by the application of mathematical morphological operators. From these anatomical and pathological models, we have developed a new framework for translating anatomical knowledge into geometrical and topological constraints. More precisely, our approach allows to automatically delineate the hepatic and portal veins but also to label the portal vein and finally to build an anatomical segmentation of the liver based on Couinaud definition which is currently used by surgeons all over the world. Finally, we have developed a user friendly interface for the 3D visualization of anatomical and pathological structures, the accurate evaluation of volumes and distances and for the virtual hepatic resection along a user-defined cutting plane. A validation study on a 30 patients database gives 2 mm of precision for liver delineation and less than 1 mm for all other anatomical and pathological structures delineation. An in vivo validation performed during surgery also showed that anatomical segmentation is more precise than the delineation performed by a surgeon based on external landmarks. This surgery planning system has been routinely used by our medical partner, and this has resulted in an improvement of the planning and performance of hepatic surgery procedures. We have developed new tools for hepatic surgical planning allowing a better surgery through an automatic delineation and visualization of anatomical and pathological structures. These tools represent a first step towards the development of an augmented

Lung cancer mimicking lung abscess formation on CT images.

Science.gov (United States)

Taira, Naohiro; Kawabata, Tsutomu; Gabe, Atsushi; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawasaki, Hidenori; Yamashiro, Toshimitsu; Ishikawa, Kiyoshi

2014-01-01

Male, 64 FINAL DIAGNOSIS: Lung pleomorphic carcinoma Symptoms: Cough • fever - Clinical Procedure: - Specialty: Oncology. Unusual clinical course. The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resembled a lung abscess on CT. We herein describe the case of 64-year-old male who was diagnosed with lung cancer using surgery. In this case, it was quite difficult to distinguish between the lung cancer and a lung abscess on CT images, and a lung abscess was initially suspected due to symptoms, such as fever and coughing, contrast-enhanced CT image findings showing a ring-enhancing mass in the right upper lobe and the patient's laboratory test results. However, a pathological diagnosis of lung cancer was confirmed according to the results of a rapid frozen section biopsy of the lesion. This case suggests that physicians should not suspect both a lung abscesses and malignancy in cases involving masses presenting as ring-enhancing lesions on contrast-enhanced CT.

Jet Ventilation during Rigid Bronchoscopy in Adults: A Focused Review

Directory of Open Access Journals (Sweden)

Laurie Putz

2016-01-01

Full Text Available The indications for rigid bronchoscopy for interventional pulmonology have increased and include stent placements and transbronchial cryobiopsy procedures. The shared airway between anesthesiologist and pulmonologist and the open airway system, requiring specific ventilation techniques such as jet ventilation, need a good understanding of the procedure to reduce potentially harmful complications. Appropriate adjustment of the ventilator settings including pause pressure and peak inspiratory pressure reduces the risk of barotrauma. High frequency jet ventilation allows adequate oxygenation and carbon dioxide removal even in cases of tracheal stenosis up to frequencies of around 150 min−1; however, in an in vivo animal model, high frequency jet ventilation along with normal frequency jet ventilation (superimposed high frequency jet ventilation has been shown to improve oxygenation by increasing lung volume and carbon dioxide removal by increasing tidal volume across a large spectrum of frequencies without increasing barotrauma. General anesthesia with a continuous, intravenous, short-acting agent is safe and effective during rigid bronchoscopy procedures.

[The flexible fiberoptic bronchoscopy report: medico-legal issues].

Science.gov (United States)

Trosini-Désert, V; Morin, J-M; Fournier, C; Similowski, T; Vergnon, J-M

2010-09-01

The flexible bronchoscopy report is one of the tools permitting exchange of medical information in respiratory medicine and is an integral part of the medical record. Currently, there is no consensus on its content, and consequently, there are no recommendations. A survey was carried out involving experts from the Groupe d'Endoscopie de Langue Française (GELF--Endoscopy Research Group of the French Language Society of Pneumology) and a lawyer from the legal affairs and patient's rights department of the Paris public hospital system. Thirty-four questions distributed in eight chapters were asked in an eight-part questionnaire covering: 1) general administration, 2) environmental safety, 3) medical and anatomical description of the examination, 4) tolerance/complications of the examination, 5) conclusion, 6) image and video sequence capture, 7) administrative data for archiving, 8) disposable elements used during the examination. The results showed as many areas of convergence as they did divergence, between physicians, and between physicians and lawyer. Collective consideration is required to harmonize the writing of bronchoscopy reports, to provide a tool that is not only consensual and complete, but also valid and sound from the medicolegal viewpoint. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Quantifying metal artefact reduction using virtual monochromatic dual-layer detector spectral CT imaging in unilateral and bilateral total hip prostheses

NARCIS (Netherlands)

Wellenberg, R. H. H.; Boomsma, M. F.; van Osch, J. A. C.; Vlassenbroek, A.; Milles, J.; Edens, M. A.; Streekstra, G. J.; Slump, C. H.; Maas, M.

2017-01-01

To quantify the impact of prosthesis material and design on the reduction of metal artefacts in total hip arthroplasties using virtual monochromatic dual-layer detector Spectral CT imaging. The water-filled total hip arthroplasty phantom was scanned on a novel 128-slice Philips IQon dual-layer

WE-FG-207B-09: Experimental Assessment of Noise and Spatial Resolution in Virtual Non-Contrast Dual-Energy CT Images Across Multiple Patient Sizes and CT Systems

International Nuclear Information System (INIS)

Montoya, J; Ferrero, A; Yu, L; Leng, S; McCollough, C

2016-01-01

Purpose: To investigate the noise and spatial resolution properties of virtual non-contrast (VNC) dual-energy CT images compared to true non-contrast (TNC) images across multiple patient sizes and CT systems. Methods: Torso-shaped water phantoms with lateral widths of 25, 30, 35, 40 and 45 cm and a high resolution bar pattern phantom (Catphan CTP528) were scanned using 2nd and 3rd generation dual-source CT systems (Scanner A: Somatom Definition Flash, Scanner B: Somatom Force, Siemens Healthcare) in dual-energy scan mode with the same radiation dose for a given phantom size. Tube potentials of 80/Sn140 and 100/Sn140 on Scanner A and 80/Sn150, 90/Sn150 and 100/Sn150 on Scanner B were evaluated to examine the impact of spectral separation. Images were reconstructed using a medium sharp quantitative kernel (Qr40), 1.0-mm thickness, 1.0-mm interval and 20 cm field of view. Mixed images served as TNC images. VNC images were created using commercial software (Virtual Unenhanced, Syngo VIA Version VA30, Siemens Healthcare). The noise power spectrum (NPS), area under the NPS, peak frequency of the NPS and image noise were measured for every phantom size and tube potential combination in TNC and VNC images. Results were compared within and between CT systems. Results: Minimal shift in NPS peak frequencies was observed in VNC images compared to TNC for NPS having pronounced peaks. Image noise and area under the NPS were higher in VNC images compared to TNC images across all tube potentials and for scanner A compared to scanner B. Limiting spatial resolution was deemed to be identical between VNC and TNC images. Conclusion: Quantitative assessment of image quality in VNC images demonstrated higher noise but equivalent spatial resolution compared to TNC images. Decreased noise was observed in the 3rd generation dual-source CT system for tube potential pairs having greater spectral separation. Dr. McCollough receives research support from Siemens Healthcare

WE-FG-207B-09: Experimental Assessment of Noise and Spatial Resolution in Virtual Non-Contrast Dual-Energy CT Images Across Multiple Patient Sizes and CT Systems

Energy Technology Data Exchange (ETDEWEB)

Montoya, J; Ferrero, A; Yu, L; Leng, S; McCollough, C [Mayo Clinic, Rochester, MN (United States)

2016-06-15

Purpose: To investigate the noise and spatial resolution properties of virtual non-contrast (VNC) dual-energy CT images compared to true non-contrast (TNC) images across multiple patient sizes and CT systems. Methods: Torso-shaped water phantoms with lateral widths of 25, 30, 35, 40 and 45 cm and a high resolution bar pattern phantom (Catphan CTP528) were scanned using 2nd and 3rd generation dual-source CT systems (Scanner A: Somatom Definition Flash, Scanner B: Somatom Force, Siemens Healthcare) in dual-energy scan mode with the same radiation dose for a given phantom size. Tube potentials of 80/Sn140 and 100/Sn140 on Scanner A and 80/Sn150, 90/Sn150 and 100/Sn150 on Scanner B were evaluated to examine the impact of spectral separation. Images were reconstructed using a medium sharp quantitative kernel (Qr40), 1.0-mm thickness, 1.0-mm interval and 20 cm field of view. Mixed images served as TNC images. VNC images were created using commercial software (Virtual Unenhanced, Syngo VIA Version VA30, Siemens Healthcare). The noise power spectrum (NPS), area under the NPS, peak frequency of the NPS and image noise were measured for every phantom size and tube potential combination in TNC and VNC images. Results were compared within and between CT systems. Results: Minimal shift in NPS peak frequencies was observed in VNC images compared to TNC for NPS having pronounced peaks. Image noise and area under the NPS were higher in VNC images compared to TNC images across all tube potentials and for scanner A compared to scanner B. Limiting spatial resolution was deemed to be identical between VNC and TNC images. Conclusion: Quantitative assessment of image quality in VNC images demonstrated higher noise but equivalent spatial resolution compared to TNC images. Decreased noise was observed in the 3rd generation dual-source CT system for tube potential pairs having greater spectral separation. Dr. McCollough receives research support from Siemens Healthcare.

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers

Energy Technology Data Exchange (ETDEWEB)

Luo, Xiongbiao, E-mail: xiongbiao.luo@gmail.com [Robarts Research Institute, Western University, London, Ontario N6A 5K8 (Canada)

2014-06-15

Purpose: Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. Methods: The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model was designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. Results: The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0–10 min{sup −1}. The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. Conclusions: An

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers

International Nuclear Information System (INIS)

Luo, Xiongbiao

2014-01-01

Purpose: Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. Methods: The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model was designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. Results: The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0–10 min −1 . The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. Conclusions: An

[Application of electric coagulation treatment via bronchoscopy in the management of congenital vallecular cyst in children].

Science.gov (United States)

Liu, Xia; Ma, Jing; Zhao, Feng-mei; Zhang, Zhong-xiao; Niu, Tie-huan; Yan, Xiu-li; Wang, Chao; Meng, Chen

2013-11-01

To discuss the effect of electric coagulation through bronchoscopy in diagnosis and treatment of congenital vallecular cyst in children. Ten cases of congenital vallecular cyst in the study with age ranged from 21 days to 4 years and 10 months were treated with electric coagulation through bronchoscopy. The therapeutic effect was evaluated by endoscopic and clinical manifestation. And all the patients were followed-up for 6-12 months. All the patients obtained 3-5 times electric coagulation. After the operation, the cyst decreased in size, epiglottis softening was subsided, uplift uncompression, dyspnea and laryngeal stridor were improved obviously. After follow-up periods of 6-12 months, no capsule wall were left, and the activity of the epiglottis resumed.No severe complication was found in any patient. Electric coagulation through bronchoscopy is a simple, effective and safe method to treat congenital vallecular cyst in children.

Diagnostic bronchoscopy: state of the art

Directory of Open Access Journals (Sweden)

V. Ninane

2010-09-01

Full Text Available Since the introduction of the flexible fibreoptic bronchoscope in the late 1960s there have been relatively few technological advances for three decades, aside from the development of a white light video bronchoscope with a miniature charge-coupled device built in its tip replacing the fibreoptics. White light flexible videobronchoscopy with its ancillary devices (forceps biopsy, bronchial brushing, bronchoalveolar lavage, bronchial washings and transbronchial needle aspiration has long been the only established diagnostic bronchoscopic technique. With the advances in microtechnology over the past two decades, recent technical developments such as autofluorescence bronchoscopy and endoscopic ultrasound allow better evaluation of endobronchial, mediastinal and parenchymal lesions.

Interventional bronchoscopy in malignant central airway obstruction by extra-pulmonary malignancy.

Science.gov (United States)

Shin, Beomsu; Chang, Boksoon; Kim, Hojoong; Jeong, Byeong-Ho

2018-03-13

Interventional bronchoscopy is considered an effective treatment option for malignant central airway obstruction (MCAO). However, there are few reports of interventional bronchoscopy in patients with MCAOs due to extra-pulmonary malignancy. Therefore, the objective of this study was to investigate treatment outcomes and prognostic factors for bronchoscopic intervention in patients with MCAO due to extra-pulmonary malignancy. We retrospectively analyzed consecutive 98 patients with MCAO due to extra-pulmonary malignancy who underwent interventional bronchoscopy between 2004 and 2014 at Samsung Medical Center (Seoul, Korea). The most common primary site of malignancy was esophageal cancer (37.9%), followed by thyroid cancer (16.3%) and head & neck cancer (10.2%). Bronchoscopic interventions were usually performed using a combination of mechanical debulking (84.7%), stent insertion (70.4%), and laser cauterization (37.8%). Of 98 patients, 76 (77.6%) patients had MCAO due to progression of malignancy, and 42 (42.9%) patients had exhausted all other anti-cancer treatment at the time of bronchoscopic intervention. Technical success was achieved in 89.9% of patients, and acute complications and procedure-related deaths occurred in 20.4% and 3.1% of patients, respectively. Reduced survival was associated with MCAO due to cancer other than thyroid cancer or lymphoma, mixed lesions, and not receiving adjuvant treatment after bronchoscopic intervention. Bronchoscopic intervention could be a safe and effective procedure for MCAO due to end-stage extra-pulmonary malignancies. In addition, we identified possible prognostic factors for poor survival after intervention, which could guide clinicians select candidates that will benefit from bronchoscopic intervention.

Web-based versus traditional lecture: are they equally effective as a flexible bronchoscopy teaching method?

Science.gov (United States)

Mata, Caio Augusto Sterse; Ota, Luiz Hirotoshi; Suzuki, Iunis; Telles, Adriana; Miotto, Andre; Leão, Luiz Eduardo Vilaça

2012-01-01

This study compares the traditional live lecture to a web-based approach in the teaching of bronchoscopy and evaluates the positive and negative aspects of both methods. We developed a web-based bronchoscopy curriculum, which integrates texts, images and animations. It was applied to first-year interns, who were later administered a multiple-choice test. Another group of eight first-year interns received the traditional teaching method and the same test. The two groups were compared using the Student's t-test. The mean scores (± SD) of students who used the website were 14.63 ± 1.41 (range 13-17). The test scores of the other group had the same range, with a mean score of 14.75 ± 1. The Student's t-test showed no difference between the test results. The common positive point noted was the presence of multimedia content. The web group cited as positive the ability to review the pages, and the other one the role of the teacher. Web-based bronchoscopy education showed results similar to the traditional live lecture in effectiveness.

Three-dimensional CT virtual endoscopy in the detection of simulated tumors in a novel phantom bladder and ureter model.

Science.gov (United States)

Russell, Shane T; Kawashima, Akira; Vrtiska, Terri J; LeRoy, Andrew J; Bruesewitz, Michael R; Hartman, Robert P; Slezak, Jeffrey M; McCollough, Cynthia H; Chow, George K; King, Bernard F

2005-03-01

Cystoscopy and ureteroscopy have limitations in the evaluation for urothelial tumors, and both are invasive. We studied the utility of three-dimensional (3D) CT virtual endoscopy in phantom models. A phantom pelvis was constructed of Plexiglas, porcine pelvic bones, and processed animal fat and scanned at various table speeds in a four detector-row CT machine for ability to detect "tumors" of Solidwater plastic polymer. Images were reconstructed at slice thicknesses of 2.5 to 5.0 mm and reconstructed in 3D for evaluation by two radiologists with no knowledge of the scanning parameters or tumor location. Similar studies were performed with a ureter model. With 5-mm slices, the sensitivity for bladder tumors ranged from 67% for 2-mm tumors to 100% for 4-mm tumors, with 12 false-positive findings. The overall sensitivity was 86% with 3.75-mm slices with one false positive, and with 2.5-mm slices, the sensitivity was 93%, again with one false positive. For the ureteral tumors, the overall sensitivities and numbers of false positives were 88.9% and eight with 5.0-mm collimation, 88.9% and four with 3.75-mm collimation, and 100% and three with 2.5-mm collimation. The effective radiation dose for all studies was equivalent to that of a standard abdomen/pelvis scan. Although virtual endoscopy traditionally has had difficulty detecting tumors <5 mm, the multidetector-row CT protocols used in this study could detect most lesions smaller than this. The scan also depicts the other tissues of the pelvis, which is valuable for staging. The 3D images were produced using data from the CT urogram parameters standard at our institution.

Comparison of virtual monoenergetic and polyenergetic images reconstructed from dual-layer detector CT angiography of the head and neck.

Science.gov (United States)

Neuhaus, Victor; Große Hokamp, Nils; Abdullayev, Nuran; Maus, Volker; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan

2018-03-01

To compare the image quality of virtual monoenergetic images and polyenergetic images reconstructed from dual-layer detector CT angiography (DLCTA). Thirty patients who underwent DLCTA of the head and neck were retrospectively identified and polyenergetic as well as virtual monoenergetic images (40 to 120 keV) were reconstructed. Signals (± SD) of the cervical and cerebral vessels as well as lateral pterygoid muscle and the air surrounding the head were measured to calculate the CNR and SNR. In addition, subjective image quality was assessed using a 5-point Likert scale. Student's t-test and Wilcoxon test were used to determine statistical significance. Compared to polyenergetic images, although noise increased with lower keV, CNR (p 0.05) of the cervical, petrous and intracranial vessels were improved in virtual monoenergetic images at 40 keV and virtual monoenergetic images at 45 keV were also rated superior regarding vascular contrast, assessment of arteries close to the skull base and small arterial branches (p virtual monoenergetic images reconstructed from DLCTA at low keV ranging from 40 to 45 keV improve the objective and subjective image quality of extra- and intracranial vessels and facilitate assessment of vessels close to the skull base and of small arterial branches. • Virtual monoenergetic images greatly improve attenuation, while noise only slightly increases. • Virtual monoenergetic images show superior contrast-to-noise ratios compared to polyenergetic images. • Virtual monoenergetic images significantly improve image quality at low keV.

Radiofrequency Ablation Assisted by Real-Time Virtual Sonography and CT for Hepatocellular Carcinoma Undetectable by Conventional Sonography

International Nuclear Information System (INIS)

Nakai, Motoki; Sato, Morio; Sahara, Shinya; Takasaka, Isao; Kawai, Nobuyuki; Minamiguchi, Hiroki; Tanihata, Hirohiko; Kimura, Masashi; Takeuchi, Nozomu

2009-01-01

Real-time virtual sonography (RVS) is a diagnostic imaging support system, which provides the same cross-sectional multiplanar reconstruction images as ultrasound images on the same monitor screen in real time. The purpose of this study was to evaluate radiofrequency ablation (RFA) assisted by RVS and CT for hepatocellular carcinoma (HCC) undetectable with conventional sonography. Subjects were 20 patients with 20 HCC nodules not detected by conventional sonography but detectable by CT or MRI. All patients had hepatitis C-induced liver cirrhosis; there were 13 males and 7 females aged 55-81 years (mean, 69.3 years). RFA was performed in the CT room, and the tumor was punctured with the assistance of RVS. CT was performed immediately after puncture, and ablation was performed after confirming that the needle had been inserted into the tumor precisely. The mean number of punctures and success rates of the first puncture were evaluated. Treatment effects were evaluated with dynamic CT every 3 months after RFA. RFA was technically feasible and local tumor control was achieved in all patients. The mean number of punctures was 1.1, and the success rate of the first puncture was 90.0%. This method enabled safe ablation without complications. The mean follow-up period was 13.5 month (range, 9-18 months). No local recurrence was observed at the follow-up points. In conclusion, RFA assisted by RVS and CT is a safe and efficacious method of treatment for HCC undetectable by conventional sonography.

Pseudo-outbreak of pseudomonas aeruginosa in HIV-infected patients undergoing fiberoptic bronchoscopy

DEFF Research Database (Denmark)

Kolmos, H J; Lerche, A; Kristoffersen, Kirsten Lydia

1994-01-01

Pseudomonas aeruginosa was isolated from bronchoalveolar lavage fluid from 8 consecutive patients undergoing bronchoscopy at an infectious diseases unit. None of the patients developed signs of respiratory tract infection that could be ascribed to the organism. The source of contamination...

The influence of airway supporting maneuvers on glottis view in pediatric fiberoptic bronchoscopy

Directory of Open Access Journals (Sweden)

Tarik Umutoglu

2015-10-01

Full Text Available ABSTRACTINTRODUCTION:Flexible fiber optic bronchoscopy is a valuable intervention for evaluation and management of respiratory diseases in both infants, pediatric and adult patients. The aim of this study is to investigate the influence of the airway supporting maneuvers on glottis view during pediatric flexible fiberoptic bronchoscopy.MATERIALS AND METHODS:In this randomized, controlled, crossover study; patients aged between 0 and 15 years who underwent flexible fiberoptic bronchoscopy procedure having American Society of Anesthesiologists I---II risk score were included. Patients having risk of difficult intubation, intubated or patients with tracheostomy, and patients with reduced neck mobility or having cautions for neck mobility were excluded from this study. After obtaining best glottic view at the neutral position, patients were positioned jaw trust with open mouth, jaw trust with teeth prottution, head tilt chin lift and triple airway maneuvers and best glottis scores were recorded.RESULTS:Total of 121 pediatric patients, 57 girls and 64 boys, were included in this study. Both jaw trust with open mouth and jaw trust with teeth prottution maneuvers improved the glottis view compared with neutral position (p 0.05. Head tilt chin lift and triple airway maneuvers improved glottis view when compared with both jaw trust with open mouth and jaw trust with teeth prottution maneuvers and neutral position (p 0.05.

CT cystography

International Nuclear Information System (INIS)

Tsili, A.

2012-01-01

Full text: Cancer of the urinary bladder is one of the commonest urothelial neoplasms. Conventional cystoscopy remains the mainstay in the diagnosis of urinary bladder carcinomas. But it is an invasive and uncomfortable procedure, associated with complications. Computed tomographic (CT) virtual cystoscopy has been proposed as an alternative imaging modality with potential advantages in the detection of urinary bladder neoplasms and good patient acceptance. It is a minimally invasive technique, allowing imaging of the urinary bladder in multiple planes and a 360 0 view. CT cystoscopy provides information about the location, size and morphologic features of urinary bladder lesions, indicating appropriate areas for biopsy. It can be performed in cases in which conventional cystoscopy is not feasible, such as in the presence of urethral strictures, marked prostatic hypertrophy or active bleeding, and in cases in which cystoscopic findings are inconclusive. The technique can be used to evaluate areas of the urinary bladder difficult to evaluate with cystoscopy, such as the anterior bladder neck and narrowmouthed diverticula. Finally, virtual cystoscopy provides both intraluminal and extraluminal pathologic changes, so intravesical disease and exrtavesical extension can be evaluated in the same study. One of the limitations of this technique is the difficulty to demonstrate small-sized lesions. The introduction of multi-detector row CT (MDCT) scanners was a major technological advancement because among other things it substantially improves z-axis resolution by reducing section collimation and allowing the detection of very small lesions. The near isotropic or isotropic pixels achieved with a multidetector CT scanner, enable the creation of multiplanar reformatted images with a resolution very close to that of the axial images and three-dimensional (3D) renderings of outstanding quality. Transverse, multiplanar reformations and virtual endoscopic images are complementary

Maintaining Oxygenation Successfully with High Flow Nasal Cannula during Diagnostic Bronchoscopy on a Postoperative Lung Transplant Patient in the Intensive Care

Directory of Open Access Journals (Sweden)

Sara Diab

2014-01-01

Full Text Available Bronchoscopy is an important diagnostic and therapeutic intervention for a variety of patients displaying pulmonary pathology. The heterogeneity of the patients undergoing bronchoscopy affords a challenge for providing minimal and safe respiratory support during anesthesia. Currently, options are intubation and general anesthesia versus frequently inadequate sedation or local anaesthesia with low flow oxygen through nasal prongs or mouthpiece. The advent of high flow nasal cannula allows the clinician to have a “middle man” that allows high flow oxygen delivery as well as a degree of respiratory support, which in some cases has been noted to be between 3 and 4 cm of continuous positive airway pressure-like effect. There are minimal data analyzing the use of high flow nasal cannula during anesthesia for bronchoscopy. We present a case report of orthotropic lung transplant recipient undergoing diagnostic bronchoscopy whilst being supported with high flow nasal oxygen in the intensive care unit.

Topical Nasal Anesthesia in Flexible Bronchoscopy--A Cross-Over Comparison between Two Devices.

Directory of Open Access Journals (Sweden)

Thomas Fuehner

Full Text Available Topical airway anesthesia is known to improve tolerance and patient satisfaction during flexible bronchoscopy (FB. Lidocaine is commonly used, delivered as an atomized spray. The current study assesses safety and patient satisfaction for nasal anesthesia of a new atomization device during outpatient bronchoscopy in lung transplant recipients.Using a prospective, non-blinded, cross-over design, patients enrolled between 01-10-2014 and 24-11-2014 received 2% lidocaine using the standard reusable nasal atomizer (CRNA. Those enrolled between 25-11-2014 and 30-01-2015, received a disposable intranasal mucosal atomization device (DIMAD. After each procedure, the treating physician, their assistant and the patient independently rated side-effects and satisfaction, basing their responses on visual analogue scales (VAS. At their next scheduled bronchoscopy during the study period, patients then received the alternative atomizer. Written consent was obtained prior to the first bronchoscopy, and the study approved by the institutional ethics committee.Of the 252 patients enrolled between 01-10-2014 and 30-01-2015, 80 (32% received both atomizers. Physicians reported better efficacy (p = 0.001 and fewer side effects (p< = 0.001 for DIMAD in patients exposed to both procedures. Among patients with one visit, physicians and their assistants reported improved efficacy (p = 0.018, p = 0.002 and fewer side effects (p< = 0.001, p = 0.029 for the disposable atomizer, whereas patients reported no difference in efficacy or side effects (p = 0.72 and p = 0.20. No severe adverse events were noted. The cost of the reusable device was 4.08€ per procedure, compared to 3.70€ for the disposable device.Topical nasal anesthesia via a disposable intranasal mucosal atomization device (DIMAD offers comparable safety and patient comfort, compared to conventional reusable nasal atomizers (CRNA in lung transplant recipients. Procedural costs were reduced by 0.34€ per

Virtual CT-colonoscopy resources in large intestine neoplasia

Directory of Open Access Journals (Sweden)

Chalyk Yu.V.

2011-12-01

Full Text Available The research goal is to state possibility of virtual colonoscopy and to determine the localization and nature of neoplasms in the large intestine. Materials and methods: 38 patients have been examined by the method of virtual colonoscopy. The preceding stage of diagnosis by total fibrocolonoscopy has not been a success. Results: Virtual colonoscopy has been performed in 94.7% of patients. The same tumors have been identified in the proximal colon, direct examination of which has not been possible. Conclusion: Virtual colonoscopy is the method of choice for topical diagnosis of tumors of the colon

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.

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.

CT simulation in nodal positive breast cancer

International Nuclear Information System (INIS)

Horst, E.; Schuck, A.; Moustakis, C.; Schaefer, U.; Micke, O.; Kronholz, H.L.; Willich, N.

2001-01-01

Background: A variety of solutions are used to match tangential fields and opposed lymph node fields in irradiation of nodal positive breast cancer. The choice is depending on the technical equipment which is available and the clinical situation. The CT simulation of a non-monoisocentric technique was evaluated in terms of accuracy and reproducibility. Patients, Material and Methods: The field match parameters were adjusted virtually at CT simulation and were compared with parameters derived mathematically. The coordinate transfer from the CT simulator to the conventional simulator was analyzed in 25 consecutive patients. Results: The angles adjusted virtually for a geometrically exact coplanar field match corresponded with the angles calculated for each set-up. The mean isocenter displacement was 5.7 mm and the total uncertainty of the coordinate transfer was 6.7 mm (1 SD). Limitations in the patient set-up became obvious because of the steep arm abduction necessary to fit the 70 cm CT gantry aperture. Required modifications of the arm position and coordinate transfer errors led to a significant shift of the marked matchline of >1.0 cm in eight of 25 patients (32%). Conclusion: The virtual CT simulation allows a precise and graphic definition of the field match parameters. However, modifications of the virtual set-up basically due to technical limitations were required in a total of 32% of cases, so that a hybrid technique was adapted at present that combines virtual adjustment of the ideal field alignment parameters with conventional simulation. (orig.) [de

Virtualized endoscope system. An application of virtual reality technology to diagnostic aid

International Nuclear Information System (INIS)

Mori, Kensaku; Urano, Akihiro; Toriwaki, Jun-ichiro; Hasegawa, Jun-ichi; Anno, Hirofumi; Katada, Kazuhiro.

1996-01-01

In this paper we propose a new medical image processing system called 'Virtualized Endoscope System (VES)', which can examine the inside of a virtualized human body. The virtualized human body is a 3-D digital image which is taken by such as X-ray CT scanner or MRI scanner. VES consists of three modules; (1) imaging, (2) segmentation and reconstruction and (3) interactive operation. The interactive operation module has following three major functions; (a) display of, (b) measurement from, and (c) manipulation to the virtualized human body. The user of the system can observe freely both the inside and the outside of a target organ from any point and any direction freely, and can perform necessary measurement interactively concerning angle and length at any time during observation. VES enables to observe repeatedly an area where the real endoscope can not enter without pain from any direction which the real endoscope can not. We applied this system to real 3-D X-ray CT images and obtained good result. (author)

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

Detection of ossicular chain abnormalities using CT imaging. Comparison of axial and virtual middle ear endoscopic imaging

International Nuclear Information System (INIS)

Sakata, Motomichi; Kamagata, Masaki; Harada, Kuniaki; Shirase, Ryuji; Oomoto, Hidechika; Himi, Tetsuo

2000-01-01

The purpose of this study was to evaluate the usefulness of axial and three-dimensional imaging (virtual endoscopy) with helical CT for the detection of ossicular chain abnormalities. In 15 patients who had traumatic ossicular dislocation, disruption, and congenital ossicular defect and anomaly, axial helical CT scanning of the temporal bone was performed with GE HSA. Axial and three-dimensional imaging was carried out in normal ears (15 ears) and abnormal ears (10 ears), for the detection of ossicular chain abnormalities. Diagnostic accuracy was evaluated by receiver-operating-characteristic (ROC) curve analysis using a continuous reporting scale. Furthermore, ROC testing was done to determine the sensitivity, specificity, and accuracy of the detection of ossicular chain abnormalities. Diagnostic accuracy in the detection of ossicular chain abnormalities with three-dimensional imaging (A z =0.967, SD=0.022) was not significantly better than that of axial imaging (A z =0.930, SD=0.046); however, the interobserver standard deviation was better for three-dimensional imaging. Three-dimensional imaging resulted in an increase in true positive cases and a decrease in false negatives. Three-dimensional imaging also showed higher sensitivity and accuracy. In the evaluation of ossicular chain abnormalities, three-dimensional imaging (virtual endoscopy) is useful and provides additional information. Three-dimensional imaging may have an important role in diagnostic procedures and/or preoperative evaluation in otology. (author)

Fospropofol Disodium for Sedation in Elderly Patients Undergoing Flexible Bronchoscopy.

Science.gov (United States)

Silvestri, Gerard A; Vincent, Brad D; Wahidi, Momen M

2011-01-01

BACKGROUND: Fospropofol disodium is a water-soluble prodrug of propofol. A subset analysis was undertaken of elderly patients (≥65 y) undergoing flexible bronchoscopy, who were part of a larger multicenter, randomized, double-blind study. METHODS: Patients received fentanyl citrate (50 mcg) followed by fospropofol at initial (4.88mg/kg) and supplemental (1.63mg/kg) doses. The primary end point was sedation success (3 consecutive Modified Observer's Assessment of Alertness/Sedation scores of ≤4 and procedure completion without alternative sedative or assisted ventilation). Treatment success, time to fully alert, patient and physician satisfaction, and safety/tolerability were also evaluated. RESULTS: In the elderly patients subset (n=61), sedation success was 92%, the mean time to fully alert was 8.0±10.9 min, and memory retention was 72% during recovery, and these were comparable with the younger patients subgroup (age, Sedation-related adverse events occurred in 23% of the elderly and 18% of the younger patients (age, sedation, rapid time to fully alert, and high satisfaction in this elderly subset undergoing flexible bronchoscopy, which was comparable with outcomes in younger patients.

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

Your Radiologist Explains CT Colonography

Medline Plus

Full Text Available ... commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large intestine or colon for cancer and growths called polyps. This procedure uses low-dose CT or CAT scanning ... Disorders Video: The Basketball Game: An ...

CT virtual endoscopy of the auditory ossicular chain and its preliminary clinical application

International Nuclear Information System (INIS)

Wang Dong; Zhang Wanshi; Xiong Minghui; Xu Jiaxing; Yu Min; Xu Changyu

2000-01-01

Objective: To evaluate the ability of CT virtual endoscopy (CTVE) in visualization of auditory ossicular chain and its clinical application. Methods: CTVE of auditory ossicular chain was performed on GE HiSpeed CT/i with 1.0 mm slice thickness at pitch 1.0, bone algorithm, 9.6 cm FOV, and 0.1 mm reconstruction interval in 10 normal subjects and 21 patients with middle ear diseases, 14 of them were proved by operation. The threshold values for normal and abnormal auditory ossicular chain were -600--200 HU and 50-300 HU respectively. Results: CTVE could clearly demonstrate the shape, size, and relation of the normal auditory ossicular chain. A visualization rate of malleus, incus, and incudomalleal articulation was 100%, and was 32% for the stapedial foot plate. However, in only 21% could the anterior and posterior crura of stapes be distinguished. Cholesteatoma was found in 12 cases with chronic otitis media, in which CTVE demonstrated varying degrees of destruction of the auditory ossicle. In 1 case with congenital anomaly, ossicle dysplasia was seen. Conclusion: CTVE being a new, non-invasive method for demonstrating the three-dimensional image of auditory ossicular chain is useful in evaluating diseases of the ear, especially the auditory ossicles

A novel needle-type sampling device for flexible ultrathin bronchoscopy

International Nuclear Information System (INIS)

Suda, Yuji; Hayashi, Katsutoshi; Shindoh, Yuriko; Iijima, Hideya; Tanaka, Akiko

2008-01-01

Diagnosis of suspected cancer in the periphery of the lung is difficult. A flexible ultrathin bronchoscope has been developed for the diagnosis of peripherally located pulmonary lesions that cannot be reached with the sampling devices for standard flexible bronchoscopes. The diagnostic yield with forceps and a brush for ultrathin bronchoscopes, however, is not adequate, especially when a lesion is not exposed to the bronchial lumen. We have thus developed a novel needle-type sampling device and tested its yield in transbronchial cytology. The device consists of an elongated dental H-file (0.4 mm in diameter and 110 cm in length), a housing sheath (1.0 mm in outer diameter), and a novel handle, which enables rapid out-and-in motion of the needle. Ten consecutive patients with a peripheral pulmonary lesion who had an indication for diagnostic procedure with a flexible ultrathin bronchoscope were enrolled. The optimal bronchial route to the lesion was analyzed with virtual bronchoscopy in a data set obtained with high-resolution computed tomography, and a novel bronchial route labeling system (prior-ridge-based relative orientation nomenclature) was employed to guide insertion of the bronchoscope. Sampling with the novel needle was performed prior to use of the forceps and brush under conventional fluoroscopy. In all the cases, sampling with the needle was successful and the amount of the specimen was sufficient for cytology. Our novel sampling system with flexible ultrathin bronchoscopes may contribute to accurate and minimally invasive diagnosis of peripheral pulmonary lesions. (author)

The Internet and medical collaboration using virtual reality.

Science.gov (United States)

Liang, Wen Yau; O'Grady, Peter

2003-01-01

Computed Tomography (CT) provides a large amount of data but the presentation of the data to a physician can be less than satisfactory. Ideally, the image data should be available to physicians in interactive 3D to allow for improved visualization, planning and diagnosis. A virtual reality representation that not only allows for the manipulation of the image but also allows for the user to, in effect, move inside the image remotely would be ideal. In this paper the research associated with virtual reality is discussed. A formalism is then presented to create, from the CT data, the virtual reality world in the Virtual Reality Modeling Language. An implementation is described of this formalism that uses the Internet to allow for users in remote locations to view and manipulate the virtual worlds.

Blunt traumatic rupture of a mainstem bronchus: spiral CT demonstration of the ''fallen lung'' sign

Energy Technology Data Exchange (ETDEWEB)

Wintermark, M.; Schnyder, P.; Wicky, S. [Dept. of Diagnostic and Interventional Radiology, University Hospital, Lausanne (Switzerland)

2001-03-01

Tracheo-bronchial injuries occur in less than 1 % of blunt chest trauma patients. Indirect signs, such as pneumomediastinum, pneumothorax, and/or subcutaneous emphysema, are revealed on admission plain films and chest CT survey. In most instances, however, tracheo-bronchoscopy is mandatory in assessing the definite diagnosis of tracheo-bronchial lesion. Occasionally, an abnormal course of a mainstem bronchus or a ''fallen lung'' sign, featuring a collapsed lung in a dependent position, hanging on the hilum only by its vascular attachments, may allow for CT diagnosis of a blunt traumatic bronchial injury. (orig.)

Comparison of virtual monoenergetic and polyenergetic images reconstructed from dual-layer detector CT angiography of the head and neck

Energy Technology Data Exchange (ETDEWEB)

Neuhaus, Victor; Grosse Hokamp, Nils; Abdullayev, Nuran; Maus, Volker; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan [University Hospital Cologne, Department of Diagnostic and Interventional Radiology, Cologne (Germany)

2018-03-15

To compare the image quality of virtual monoenergetic images and polyenergetic images reconstructed from dual-layer detector CT angiography (DLCTA). Thirty patients who underwent DLCTA of the head and neck were retrospectively identified and polyenergetic as well as virtual monoenergetic images (40 to 120 keV) were reconstructed. Signals (± SD) of the cervical and cerebral vessels as well as lateral pterygoid muscle and the air surrounding the head were measured to calculate the CNR and SNR. In addition, subjective image quality was assessed using a 5-point Likert scale. Student's t-test and Wilcoxon test were used to determine statistical significance. Compared to polyenergetic images, although noise increased with lower keV, CNR (p < 0.02) and SNR (p > 0.05) of the cervical, petrous and intracranial vessels were improved in virtual monoenergetic images at 40 keV and virtual monoenergetic images at 45 keV were also rated superior regarding vascular contrast, assessment of arteries close to the skull base and small arterial branches (p < 0.0001 each). Compared to polyenergetic images, virtual monoenergetic images reconstructed from DLCTA at low keV ranging from 40 to 45 keV improve the objective and subjective image quality of extra- and intracranial vessels and facilitate assessment of vessels close to the skull base and of small arterial branches. (orig.)

Usefulness of virtual endoscopy for evaluating the relationship between the neck of intracranial aneurysm and surrounding vessels

International Nuclear Information System (INIS)

Ikeda, Jota; Horie, Hitoshi; Ishikura, Reiichi; Ando, Kumiko; Morikawa, Tsutomu; Tominaga, Satoru; Nakao, Norio

2000-01-01

Application of three-dimensional CT virtual endoscopy for evaluation of the neck and surrounding vessels of intracranial aneurysms. 3D-CT virtual endoscopy (VE) is a reconstructed image using computer processing of 3D-CT images. We evaluated the usefulness of a virtual endoscopy to analyze the relationship between the neck of an intracranial aneurysm and the surrounding vessels. Eight cases with intracranial aneurysms underwent digital subtraction angiography (DSA) and enhanced CT with transarterial infusion of contrast media. 3D-CT angiogram (3D-CTA) and virtual endoscopic images were obtained from the CT image data sets using surface rendering method. The relationship between the neck of an intracranial aneurysm and the surrounding vessels was confirmed by operation or IVR. VE clearly visualized the neck and surrounding vessels in all cases. Operation/IVR findings agreed with the virtual endoscopic findings in all cases, but not with the DSA or 3D-CTA findings in 4 and 2 cases, respectively. 3D-CTA and virtual endoscopy clearly visualizes the relationship between cerebral aneurysms and surrounding vessels, which is useful for determining IVR procedures. (author)

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

International Nuclear Information System (INIS)

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

2005-01-01

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. (orig.)

Distributed practice. The more the merrier? A randomised bronchoscopy simulation study

OpenAIRE

Bjerrum, Anne Sofie; Eika, Berit; Charles, Peder; Hilberg, Ole

2016-01-01

Introduction: The distribution of practice affects the acquisition of skills. Distributed practice has shown to be more effective for skills acquisition than massed training. However, it remains unknown as to which is the most effective distributed practice schedule for learning bronchoscopy skills through simulation training. This study compares two distributed practice schedules: One-day distributed practice and weekly distributed practice.Method: Twenty physicians in training were randomly...

Evaluation of a flexible bronchoscope prototype designed for bronchoscopy during mechanical ventilation: a proof-of-concept study.

Science.gov (United States)

Nay, M-A; Auvet, A; Mankikian, J; Herve, V; Dequin, P-F; Guillon, A

2017-06-01

Bronchoscopy during mechanical ventilation of patients' lungs significantly affects ventilation because of partial obstruction of the tracheal tube, and may thus be omitted in the most severely ill patients. It has not previously been possible to reduce the external diameter of the bronchoscope without reducing the diameter of the suction channel, thus reducing the suctioning capacity of the device. We believed that a better-designed bronchoscope could improve the safety of bronchoscopy in patients whose lungs were ventilated. We designed a flexible bronchoscope prototype with a drumstick-shaped head consisting of a long, thin proximal portion; a short and large distal portion for camera docking; and a large suction channel throughout the length of the device. The aims of our study were to test the impact of our prototype on mechanical ventilation when inserted into the tracheal tube, and to assess suctioning capacity. We first tested the efficiency of the suction channel, and demonstrated that the suction flow of the prototype was similar to that of conventional adult bronchoscopes. We next evaluated the consequences of bronchoscopy when using the prototype on minute ventilation and intrathoracic pressures during mechanical ventilation: firstly, in vitro using a breathing simulator; and secondly, in vivo using a porcine model of pulmonary ventilation. The insertion of adult bronchoscopes into the tracheal tube immediately impaired the protective ventilation strategy employed, whereas the prototype preserved it. For the first time, we have developed an innovative flexible bronchoscope designed for bronchoscopy during invasive mechanical ventilation, that both preserved the protective ventilation strategy, and enabled efficient suction flow. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Clinical applications of imaging reconstruction by virtual sonography

International Nuclear Information System (INIS)

Mori, Akihiro; Oohashi, Noritsugu; Maruyama, Takako; Tatebe, Hideharu; Fushimi, Nobutoshi; Asano, Takayuki; Inoue, Hiroshi; Okuno, Masataka

2008-01-01

One of the pitfalls in managing multiple liver tumors is the difficulty in identifying individual tumors on ultrasonography. Computed tomography (CT)-assisted virtual sonography has been shown to improve sonographic diagnosis, however it requires additional equipment and software. We have developed a simple reconstruction method of virtual sonography (SRVS). We reconstructed SRVS mimicking ultrasonographic images, utilizing a workstation software attached to a multi-detector row CT system without any additional program. We have performed SRVS in 32 patients with 41 liver tumors that could hardly be identify on ultrasonography. SRVS assisted the identification of malignant form non-pathologic ones and thereby contributed to the appropriate clinical strategy including radiofrequency ablation (RFA) (18 tumors), liver biopsy (2 tumors), other therapies (4 tumors) and follow-up (17 tumors). We have developed virtual sonography using conventional CT software. SRVS seems useful in the clinical practice in managing liver tumors. (author)

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

Material Separation Using Dual-Energy CT: Current and Emerging Applications.

Science.gov (United States)

Patino, Manuel; Prochowski, Andrea; Agrawal, Mukta D; Simeone, Frank J; Gupta, Rajiv; Hahn, Peter F; Sahani, Dushyant V

2016-01-01

Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine. These iodine-specific images increase tissue contrast and amplify subtle differences in attenuation between normal and abnormal tissues, improving lesion detection and characterization in the abdomen. In addition, DE CT enables computational removal of iodine influence from a CT image, generating virtual noncontrast images. Several additional materials, including calcium, fat, and uric acid, can be separated, permitting imaging assessment of metabolic imbalances, elemental deficiencies, and abnormal deposition of materials within tissues. The ability to obtain material-specific images from a single, contrast-enhanced CT acquisition can complement the anatomic knowledge with functional information, and may be used to reduce the radiation dose by decreasing the number of phases in a multiphasic CT examination. DE CT also enables generation of energy-specific and virtual monochromatic images. Clinical applications of DE CT leverage both material-specific images and virtual monochromatic images to expand the current role of CT and overcome several limitations of single-energy CT. (©)RSNA, 2016.

Role of flexible bronchoscopy and bronchoalveolar lavage in the diagnosis of pediatric acquired immunodeficiency syndrome-related pulmonary disease.

Science.gov (United States)

Birriel, J A; Adams, J A; Saldana, M A; Mavunda, K; Goldfinger, S; Vernon, D; Holzman, B; McKey, R M

1991-06-01

Flexible fiberoptic bronchoscopy with bronchoalveolar lavage was performed in 16 pediatric patients with the acquired immunodeficiency syndrome (AIDS) and deterioration in pulmonary function suggestive of opportunistic infection. In 62% of the patients Pneumocystis carinii was identified. Culture results showed a pure growth of Pseudomonas aeruginosa for one patient in addition to the Pneumocystis carinii. Bronchoscopy with lavage was well tolerated, with few complications even among patients with significant tachypnea and hypoxia. Because of its relative safety and effectiveness, this procedure should be considered the first invasive measurement used for evaluation of parenchymal lung disease in this population of patients.

Post-bronchoscopy fatal endobronchial hemorrhage in a woman with bronchopulmonary mucormycosis: a case report

Directory of Open Access Journals (Sweden)

La Licata Francesco

2010-12-01

Full Text Available Abstract Introduction During infection, Mucorales fungi invade major blood vessels, leading to extensive necrosis, and in cases of extensive pulmonary disease, bleeding into the lungs may occur. Case presentation We report an unexpected event of post-bronchoscopy fatal endobronchial hemorrhage in a 62-year-old HIV-negative Italian woman with well controlled diabetes mellitus who presented with diffuse cavitated pulmonary lesions. Fiberoptic bronchoscopy revealed bilateral obstruction of the segmental bronchi. Fatal massive bleeding occurred after standard biopsy procedures. Histologic examination showed that the hyphae were more deeply colored by hematoxylin-eosin (H&E than by other stains for fungi. Culture and autopsy confirmed bronchopulmonary mucormycosis. Conclusion Infection by Mucorales fungi should be considered in the diabetes population regardless of the degree of metabolic control. In these patients, particular caution should be taken during bronchoscopic procedures because of the greater friability of the fungal lesions.

Commentary on “Music Does Not Alter Anxiety in Patients with Suspected Lung Cancer Undergoing Bronchoscopy: A Randomised Controlled Trial” – European Clinical Respiratory Journal

DEFF Research Database (Denmark)

Jeppesen, Elisabeth; Pedersen, Carsten Michel

2016-01-01

Introduction Not only may the prognosis of lung cancer provoke fear in patients with suspected lung cancer undergoing bronchoscopy, but also the thought of undergoing bronchoscopy may provoke fear [1]. This can be fear of pain, of shortness of breath and also fear of death in connection with the ...

Accident response -- X-ray to virtual environment

International Nuclear Information System (INIS)

Hefele, J.; Stupin, D.; Kelley, T.; Sheats, M.; Tsai, C.

1999-01-01

The Engineering Sciences and Applications (ESA) Division of Los Alamos National Laboratory (LANL) has been working to develop a process to extract topographical information from digital x-ray data for modeling in a Computer Aided Design (CAD) environment and translation into a virtual environment. The application for this process is the evolution of a field deployable tool for use by the Accident Response Group (ARG) at the Laboratory. The authors have used both CT Scan and radiography data in their process development. The data is translated into a format recognizable by Pro/ENGINEER trademark and then into a virtual environment that can be operated on by dVISE trademark. They have successfully taken both CT Scan and radiograph data of single components and created solid and virtual environment models for interrogation

Free-breathing cine CT for the diagnosis of tracheomalacia in young children

International Nuclear Information System (INIS)

Goo, Hyun Woo

2013-01-01

Tracheomalacia is characterized by excessive expiratory collapse of the trachea. To investigate the accuracy of free-breathing cine CT for diagnosis of tracheomalacia in young children with bronchoscopy as reference standard. In a retrospective study (May 2001-July 2008), a patient group (n = 27) of children with bronchoscopic evidence of tracheomalacia, and a control group (n = 320) underwent free-breathing cine CT. The tracheal shape on free-breathing cine CT was classified as round, lunate, elongated or crescentic. Cross-sectional area change of the trachea and age were compared between the groups and the diagnostic performance of free-breathing cine CT for tracheomalacia was evaluated. The patient group showed significantly greater cross-sectional area change of the trachea (57.2% ± 22.2% vs. 10.6% ± 11.2%, P < 0.001) than the control group. If a cross-sectional area change of the trachea of 31.6% was used as a cut-off value for the diagnosis of tracheomalacia, the sensitivity, specificity and accuracy of cine CT were 96.3% (26/27), 97.2% (311/320) and 97.1% (337/347), respectively. If a crescentic shape during the expiratory phase was used, the sensitivity, specificity and accuracy were 51.9% (14/27), 98.8% (316/320) and 95.1% (330/347), respectively. Free-breathing cine CT has potential to provide the diagnosis of tracheomalacia in young children. (orig.)

Virtual simulation of radiotherapeutic treatment of the prostate

Energy Technology Data Exchange (ETDEWEB)

Haest, K; Vanregemorter, J [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium). Dept. of Radiotherapy; Van Dam, J [Louvain Univ. (Belgium)

1995-12-01

Virtual simulation allows to simulate the radiotherapeutic treatment by computer, based on a CT scan of the patient in treatment position. The routinely obtained CT scans of prostate cancer patients in treatment position were used after conventional simulation for a parallel virtual simulation. In a first step the three-dimensional electron density data of the CT were used to outline the prostate and critical organs as three-dimensional volumes of interest. Based on the 3D information of the pre-defined target volume and a pre-set 3D margin, beams and beam blocks were automatically generated according to the beam set-up. A beam`s-eye view of the volumes of interest was calculated for each beam, superimposed on a digitally reconstructed radiograph using the actual divergence of the beam. At the same time the dose distribution was computed for the fields and blocks generated by the virtual simulator. The resulting Dose Volume Histograms for prostate, rectum and bladder were reviewed and compared with the Dose Volume Histograms obtained from the conventional simulation process. During both virtual and conventional simulation, time commitments required for all the members of the radiotherapy treatment team were recorded. It is concluded that routine use of virtual simulation is possible in a busy radiation oncology department; virtual simulation results in most cases in smaller field sizes than conventional simulation; Dose Volume Histograms show that virtual simulation of the prostate minimizes the dose delivered to the bladder; a shift in workload can be expected from technicians towards physicists and medical doctors with an overall decrease in time for both personnel and patient.

Virtual simulation of radiotherapeutic treatment of the prostate

International Nuclear Information System (INIS)

Haest, K.; Vanregemorter, J.

1995-01-01

Virtual simulation allows to simulate the radiotherapeutic treatment by computer, based on a CT scan of the patient in treatment position. The routinely obtained CT scans of prostate cancer patients in treatment position were used after conventional simulation for a parallel virtual simulation. In a first step the three-dimensional electron density data of the CT were used to outline the prostate and critical organs as three-dimensional volumes of interest. Based on the 3D information of the pre-defined target volume and a pre-set 3D margin, beams and beam blocks were automatically generated according to the beam set-up. A beam's-eye view of the volumes of interest was calculated for each beam, superimposed on a digitally reconstructed radiograph using the actual divergence of the beam. At the same time the dose distribution was computed for the fields and blocks generated by the virtual simulator. The resulting Dose Volume Histograms for prostate, rectum and bladder were reviewed and compared with the Dose Volume Histograms obtained from the conventional simulation process. During both virtual and conventional simulation, time commitments required for all the members of the radiotherapy treatment team were recorded. It is concluded that routine use of virtual simulation is possible in a busy radiation oncology department; virtual simulation results in most cases in smaller field sizes than conventional simulation; Dose Volume Histograms show that virtual simulation of the prostate minimizes the dose delivered to the bladder; a shift in workload can be expected from technicians towards physicists and medical doctors with an overall decrease in time for both personnel and patient

CTA-enhanced perfusion CT: an original method to perform ultra-low-dose CTA-enhanced perfusion CT

Energy Technology Data Exchange (ETDEWEB)

Tong, Elizabeth; Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States)

2014-11-15

Utilizing CT angiography enhances image quality in PCT, thereby permitting acquisition at ultra-low dose. Dynamic CT acquisitions were obtained at 80 kVp with decreasing tube current-time product [milliamperes x seconds (mAs)] in patients suspected of ischemic stroke, with concurrent CTA of the cervical and intracranial arteries. By utilizing fast Fourier transformation, high spatial frequencies of CTA were combined with low spatial frequencies of PCT to create a virtual PCT dataset. The real and virtual PCT datasets with decreasing mAs were compared by assessing contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and noise and PCT values and by visual inspection of PCT parametric maps. Virtual PCT attained CNR and SNR three- to sevenfold superior to real PCT and noise reduction by a factor of 4-6 (p < 0.05). At 20 mAs, virtual PCT achieved diagnostic parametric maps, while the quality of real PCT maps was inadequate. At 10 mAs, both real and virtual PCT maps were nondiagnostic. Virtual PCT (but not real PCT) maps regained diagnostic quality at 10 mAs by applying 40 % adaptive statistical iterative reconstruction (ASIR) and improved further with 80 % ASIR. Our new method of creating virtual PCT by combining ultra-low-dose PCT with CTA information yields diagnostic perfusion parametric maps from PCT acquired at 20 or 10 mAs with 80 % ASIR. Effective dose is approximately 0.20 mSv, equivalent to two chest radiographs. (orig.)

A CT-assisted method of dosimetry in brachytherapy of lung cancer

International Nuclear Information System (INIS)

Senan, S.; Lagerwaard, F.J.; Pan, C. de; Sipkema, D.; Murrer, L.H.P.; Burgers, S.A.

2000-01-01

The toxicity of endobronchial brachytherapy (EB), in particular fatal haemoptysis and bronchial wall necrosis, has been correlated with the total dose, fraction size, volume encompassed by the 100% isodose, and a proximal tumor location. We describe a CT-based planning method which, by improving target volume definition and volumeric dose information, can improve the therapeutic ratio of EB. Sixteen CT-assisted EB procedures were performed in patients who were treated with palliative high-dose rate EB. The CT data were used to analyze applicator position in relation to anatomy. An example of a three-dimensional optimized treatment plan was generated and analyzed using different types of dose-volume histograms. The procedure was well tolerated by patients and no post-procedure complications were observed. The bronchial applicator was eccentrically positioned at the level of the carina/mainstem bronchus in 12 (of 14) CT scans. A planning CT prior to EB was not found to be useful as the final target volume and/or the final applicator position were not reliably predicted before the therapeutic bronchoscopy. CT-scans performed with the applicator in situ allowed the bronchial segments in the target volume to be identified and enabled dose prescription to the bronchial mucosa. CT-assisted EB is feasible and underlines the need for using centered applicators for proximally located tumors. By enabling accurate mucosal dose prescription, CT-assisted EB may reduce the toxicity of fractionated EB in the curative setting. However, faster on-line EB treatment planning is needed for the routine clinical application of this technique. (author)

TH-CD-202-04: Evaluation of Virtual Non-Contrast Images From a Novel Split-Filter Dual-Energy CT Technique

International Nuclear Information System (INIS)

Huang, J; Szczykutowicz, T; Bayouth, J; Miller, J

2016-01-01

Purpose: To compare the ability of two dual-energy CT techniques, a novel split-filter single-source technique of superior temporal resolution against an established sequential-scan technique, to remove iodine contrast from images with minimal impact on CT number accuracy. Methods: A phantom containing 8 tissue substitute materials and vials of varying iodine concentrations (1.7–20.1 mg I /mL) was imaged using a Siemens Edge CT scanner. Dual-energy virtual non-contrast (VNC) images were generated using the novel split-filter technique, in which a 120kVp spectrum is filtered by tin and gold to create high- and low-energy spectra with < 1 second temporal separation between the acquisition of low- and high-energy data. Additionally, VNC images were generated with the sequential-scan technique (80 and 140kVp) for comparison. CT number accuracy was evaluated for all materials at 15, 25, and 35mGy CTDIvol. Results: The spectral separation was greater for the sequential-scan technique than the split-filter technique with dual-energy ratios of 2.18 and 1.26, respectively. Both techniques successfully removed iodine contrast, resulting in mean CT numbers within 60HU of 0HU (split-filter) and 40HU of 0HU (sequential-scan) for all iodine concentrations. Additionally, for iodine vials of varying diameter (2–20 mm) with the same concentration (9.9 mg I /mL), the system accurately detected iodine for all sizes investigated. Both dual-energy techniques resulted in reduced CT numbers for bone materials (by >400HU for the densest bone). Increasing the imaging dose did not improve the CT number accuracy for bone in VNC images. Conclusion: VNC images from the split-filter technique successfully removed iodine contrast. These results demonstrate a potential for improving dose calculation accuracy and reducing patient imaging dose, while achieving superior temporal resolution in comparison sequential scans. For both techniques, inaccuracies in CT numbers for bone materials

TH-CD-202-04: Evaluation of Virtual Non-Contrast Images From a Novel Split-Filter Dual-Energy CT Technique

Energy Technology Data Exchange (ETDEWEB)

Huang, J; Szczykutowicz, T; Bayouth, J; Miller, J [University of Wisconsin, Madison, WI (United States)

2016-06-15

Purpose: To compare the ability of two dual-energy CT techniques, a novel split-filter single-source technique of superior temporal resolution against an established sequential-scan technique, to remove iodine contrast from images with minimal impact on CT number accuracy. Methods: A phantom containing 8 tissue substitute materials and vials of varying iodine concentrations (1.7–20.1 mg I /mL) was imaged using a Siemens Edge CT scanner. Dual-energy virtual non-contrast (VNC) images were generated using the novel split-filter technique, in which a 120kVp spectrum is filtered by tin and gold to create high- and low-energy spectra with < 1 second temporal separation between the acquisition of low- and high-energy data. Additionally, VNC images were generated with the sequential-scan technique (80 and 140kVp) for comparison. CT number accuracy was evaluated for all materials at 15, 25, and 35mGy CTDIvol. Results: The spectral separation was greater for the sequential-scan technique than the split-filter technique with dual-energy ratios of 2.18 and 1.26, respectively. Both techniques successfully removed iodine contrast, resulting in mean CT numbers within 60HU of 0HU (split-filter) and 40HU of 0HU (sequential-scan) for all iodine concentrations. Additionally, for iodine vials of varying diameter (2–20 mm) with the same concentration (9.9 mg I /mL), the system accurately detected iodine for all sizes investigated. Both dual-energy techniques resulted in reduced CT numbers for bone materials (by >400HU for the densest bone). Increasing the imaging dose did not improve the CT number accuracy for bone in VNC images. Conclusion: VNC images from the split-filter technique successfully removed iodine contrast. These results demonstrate a potential for improving dose calculation accuracy and reducing patient imaging dose, while achieving superior temporal resolution in comparison sequential scans. For both techniques, inaccuracies in CT numbers for bone materials

Three-dimensional-CT imaging of colorectal disease with thin collimation helical CT scanning

International Nuclear Information System (INIS)

Ogura, Toshihiro; Koizumi, Koichi; Sakai, Tatsuya; Kai, Shunkichi; Takatsu, Kazuaki; Maruyama, Masakazu

1998-01-01

We have conducted research on three-dimensional (3D)-CT-colonoscopy with thin collimation helical CT scanning over the past three years. This has lately become a subject of special interest. 3D-CT-colonoscopy has three kinds of visualizing methods depending on the threshold setting of CT values. The first one is the virtual endoscopy method which is displayed in a similar fashion to colonoscopic images. The second one is the air image method using the air in the digestive tract as a contrast medium. The third one is the pseudo-tract method which has characteristics of both virtual endoscopy and the air image method and visualizes in a shape of the digestive tract. The image visualized by 3D-CT-colonoscopy is similar to that of conventional colonoscopy and barium enema study, which is obtained with minimal invasion to patients. Obvious advanced carcinomas were easily visualized, and even a small flat polyp measuring 5 mm in size, was able to be observed retrospectively. The characteristics of our method are that we can easily make an examination in a short time and with little dependence on expert technique. Also patients have little discomfort compared to that experienced during colonoscopy and barium enema study. Important features are as follows; long calculation time, insufficient air insufflation, fecal material in the patient''s bowel, whole abdominal scan, and spatial resolution. In the near future, a multislice CT scanner system will have ability to overcome these problems. Therefore, 3D-CT-colonoscopy might be applied in the future for first line examination as a mass screening for colorectal carcinoma. (author)

Conventional versus virtual radiographs of the injured pelvis and acetabulum

Energy Technology Data Exchange (ETDEWEB)

Bishop, Julius A.; Rao, Allison J.; Pouliot, Michael A.; Bellino, Michael [Stanford University School of Medicine, Department of Orthopaedic Surgery, Stanford, CA (United States); Beaulieu, Christopher [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

2015-09-15

Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans. Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA). Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well. Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs. (orig.)

Multidetector CT of the colon

International Nuclear Information System (INIS)

Luboldt, W.; Hoepffner, N.; Holzer, K.

2003-01-01

Multidetector technology, enabling faster imaging, higher spatial resolution and reduction in radiation dose, increases the role of CT in colonic diagnostic. The higher spatial resolution in the z-direction also changes the way to analyze the images. Instead of reading axial sections, now the colon can be systematically assessed in 3D by scrolling through multiplanar reconstructions or in CT colonography by virtual endoscopy. With ongoing improvements in computer-aided diagnosis CT colonography becomes an alternative to fiberoptic colonocopy for screening (http://www.multiorganscreening.org). In this article we propose a CT examination protocol for the colon, describe the typical imaging findings of different colonic diseases, and summarize the current status of CT colonography. (orig.)

Analysis of patient CT dose data using virtualdose

Science.gov (United States)

Bennett, Richard

X-ray computer tomography has many benefits to medical and research applications. Recently, over the last decade CT has had a large increase in usage in hospitals and medical diagnosis. In pediatric care, from 2000 to 2006, abdominal CT scans increased by 49 % and chest CT by 425 % in the emergency room (Broder 2007). Enormous amounts of effort have been performed across multiple academic and government groups to determine an accurate measure of organ dose to patients who undergo a CT scan due to the inherent risks with ionizing radiation. Considering these intrinsic risks, CT dose estimating software becomes a necessary tool that health care providers and radiologist must use to determine many metrics to base the risks versus rewards of having an x-ray CT scan. This thesis models the resultant organ dose as body mass increases for patients with all other related scan parameters fixed. In addition to this,this thesis compares a modern dose estimating software, VirtualDose CT to two other programs, CT-Expo and ImPACT CT. The comparison shows how the software's theoretical basis and the phantom they use to represent the human body affect the range of results in organ dose. CT-Expo and ImPACT CT dose estimating software uses a different model for anatomical representation of the organs in the human body and the results show how that approach dramatically changes the outcome. The results categorizes four datasets as compared to the three software types where the appropriate phantom was available. Modeling was done to simulate chest abdominal pelvis scans and whole body scans. Organ dose difference versus body mass index shows as body mass index (BMI) ranges from 23.5 kg/m 2 to 45 kg/m2 the amount of organ dose also trends a percent change from -4.58 to -176.19 %. Comparing organ dose difference with increasing x-ray tube potential from 120 kVp to 140 kVp the percent change in organ dose increases from 55 % to 65 % across all phantoms. In comparing VirtualDose to CT

Clinical studies on the visualization of gastric lesions using virtual CT endoscopy

International Nuclear Information System (INIS)

Kim, Hideki; Takashima, Sumio; Kaminou, Toshio; Hayashi, Seisyo; Nishida, Norifumi; Matsuoka, Toshiyuki; Nakamura, Kenji; Yamada, Ryusaku

2001-01-01

We evaluated the clinical usefulness of virtual CT gastro endoscopy (VCTGE). The subjects were 124 patients with endoscopically identified gastric lesions. VCTGE images were obtained using a GE-Navigator. We evaluated VCTGE in the visualization of gastric lesions for their presence and morphology. The detection rate of all gastric lesions by VCTGE was 76% (94 of 124 patients). The smallest detectable early gastric cancer was II c measuring 10 x 8 mm. The detection rates of each gastric lesion by VCTGE were 73% in early gastric cancer, and 90% in advanced gastric cancer. VCTGE imaging in the advanced gastric cancer was good in 12 (30%), fair in 25 (60%) and poor in 4 (10%). VCTGE imaging in early gastric cancer was good in 20 (46%), fair in 12 (27%) and poor in 12 (27%). The significance P level was 0.005 between the evaluation of the imaging of advanced and early gastric cancer. VCTGE visualized the characteristics of diverse gastric lesions and was considered useful for the detection and the diagnosis of these lesions. (author)

A virtual radiation therapy workflow training simulation

International Nuclear Information System (INIS)

Bridge, P.; Crowe, S.B.; Gibson, G.; Ellemor, N.J.; Hargrave, C.; Carmichael, M.

2016-01-01

Aim: Simulation forms an increasingly vital component of clinical skills development in a wide range of professional disciplines. Simulation of clinical techniques and equipment is designed to better prepare students for placement by providing an opportunity to learn technical skills in a “safe” academic environment. In radiotherapy training over the last decade or so this has predominantly comprised treatment planning software and small ancillary equipment such as mould room apparatus. Recent virtual reality developments have dramatically changed this approach. Innovative new simulation applications and file processing and interrogation software have helped to fill in the gaps to provide a streamlined virtual workflow solution. This paper outlines the innovations that have enabled this, along with an evaluation of the impact on students and educators. Method: Virtual reality software and workflow applications have been developed to enable the following steps of radiation therapy to be simulated in an academic environment: CT scanning using a 3D virtual CT scanner simulation; batch CT duplication; treatment planning; 3D plan evaluation using a virtual linear accelerator; quantitative plan assessment, patient setup with lasers; and image guided radiotherapy software. Results: Evaluation of the impact of the virtual reality workflow system highlighted substantial time saving for academic staff as well as positive feedback from students relating to preparation for clinical placements. Students valued practice in the “safe” environment and the opportunity to understand the clinical workflow ahead of clinical department experience. Conclusion: Simulation of most of the radiation therapy workflow and tasks is feasible using a raft of virtual reality simulation applications and supporting software. Benefits of this approach include time-saving, embedding of a case-study based approach, increased student confidence, and optimal use of the clinical environment

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.

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

Science.gov (United States)

Lundin, Margareta; Lidén, Mats; Magnuson, Anders; Mohammed, Ahmed Abdulilah; Geijer, Håkan; Andersson, Torbjörn; Persson, Anders

2012-07-01

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. 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. 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. 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. 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.

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

International Nuclear Information System (INIS)

Lundin, Margareta; Liden, Mats; Geijer, Haakan; Andersson, Torbjoern; Magnuson, Anders; Mohammed, Ahmed Abdulilah; Persson, Anders

2012-01-01

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

Comparing Patient Satisfaction and Intubating Conditions Using Succinylcholine or Low-Dose Rocuronium for Rigid Bronchoscopy: A Randomized Study.

Science.gov (United States)

Ghezel-Ahmadi, Verena; Ghezel-Ahmadi, David; Mangen, Jacques; Bolukbas, Servet; Welker, Andreas; Kuerschner, Veit Christian; Fischer, Andreas; Schirren, Joachim; Beck, Grietje

2015-09-01

Despite its serious side effects, succinylcholine is commonly used for neuromuscular relaxation in short procedures, such as rigid bronchoscopy and tracheobronchial interventions. The application of low-dose rocuronium reversed by low-dose sugammadex might be a modern alternative. The aim of this study was to compare patient satisfaction, incidence of postoperative myalgia (POM) as well as intubating conditions of these two muscle relaxants for rigid bronchoscopy. A single-center, prospective-randomized, blinded study of 95 patients, scheduled for rigid bronchoscopy and tracheobronchial intervention was conducted. The patients were anesthetized with propofol, remifentanil and either low-dose succinylcholine (S) (0.5 mg/kg) or low-dose rocuronium (0.25 mg/kg) with sugammadex (RS) (0.5 mg/kg). All patients were evaluated on the first and second postinterventional day for their satisfaction with the treatment (rigid bronchoscopy) using a Numeric Analog Rating Scale (NAS 0-10) and the presence and severity of POM (NAS 1-4). Intubating conditions were assessed as excellent, good, or poor on the basis of position of vocal cords and reaction to insertion of the rigid bronchoscope. Patients in the S group were less satisfied with the treatment than patients in RS group (72.7 vs. 93.7%, p = 0.007). The incidence of POM on the first day after intervention was significantly higher in the S group then in the RS group (56.9% vs. 4.3%, p rocuronium in 75% of patients. The anesthetic drug costs were significantly higher in the RS group then in the S group (p rocuronium provided better patient satisfaction and less POM. But with the use of low-dose succinylcholine, the intubating conditions are more comfortable, and it is less expensive than rocuronium/sugammadex. Georg Thieme Verlag KG Stuttgart · New York.

Role of bronchoscopy in evaluation of cases with sputum smear negative pulmonary tuberculosis, interstitial lung disease and lung malignancy: A retrospective study of 712 cases.

Science.gov (United States)

Kumar, Raj; Gupta, Nitesh

2015-01-01

The introduction of flexible bronchoscope has revolutionized the field of pulmonary medicine and is a standard instrument used for diagnostic purpose. A retrospective analysis of the clinico-radiological profile, indication, biopsy procedure and complications, for patients undergoing bronchoscopy at one of the respiratory unit at a tertiary care center in India. Retrospective analysis of 712 bronchoscopies was done in regard to demographic profile, clinical and radiological presentation and diagnostic indication. The results were analyzed on basis of bronchoscopy inspection and histopathological specimen obtained from transbronchial (TBLB), endobronchial biopsy (EBLB) and cytology specimen by transbronchial needle aspiration (TBNA). Furthermore, diagnostic yield of each biopsy procedure and their combination was evaluated. Of 712 patients undergoing bronchoscopy, the pathological diagnosis was achieved in 384 (53.93%). Of 384 diagnosed cases, the clinic-radio-pathological diagnosis of pulmonary tuberculosis in 88 (22.19%), interstitial lung disease (ILDs) in 226 (58.85%), and lung cancer in 70 (18.22%) cases. Of 116 sputum smear negative tuberculosis patients, 88 (75.86%) were diagnosed to be pulmonary tuberculosis; the contribution of BAL being 71.59%. Of 226 ILDs, sarcoidosis was most common 148/226 (65.48%). Among 70 lung cancer diagnosed cases, squamous cell carcinoma was most common (54.28%). The results from current study reemphasizes on the diagnostic utility as well as safety of the bronchoscopy procedure. Copyright © 2015 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Yoo, Seon Young; Kim, Yoo Kyung; Cho, Hyun Hae; Choi, Mi Joo; Shim, Sung Shine; Lee, Jeong Kyong; Baek, Seung Yon

2013-01-01

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.

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.

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

Science.gov (United States)

Yoo, Seon Young; Kim, Yookyung; Cho, Hyun Hae; Choi, Mi Joo; Shim, Sung Shine; Lee, Jeong Kyong; Baek, Seung Yon

2013-01-01

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.

Methylene Blue-Aided In Vivo Staining of Central Airways during Flexible Bronchoscopy

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Sabine Zirlik

2012-01-01

Full Text Available Background. The early diagnosis of malignant and premalignant changes of the bronchial mucosa remains a major challenge during bronchoscopy. Intravital staining techniques are not new. Previous small case series suggested that analysis of the bronchial mucosal surface using chromoendoscopy allows a prediction between neoplastic and nonneoplastic lesions. Objectives. The aim of the present study was to evaluate chromobronchoscopy as a method to identify malignant and premalignant lesions in the central airways in a prospective manner. Methods. In 26 patients we performed chromoendoscopy with 0.1% methylene blue during ongoing flexible white light bronchoscopy. Circumscribed lesions in central airways were further analyzed by biopsies and histopathologic examination. Results. In the majority of cases neither flat nor polypoid lesions in the central airways were stained by methylene blue. In particular, exophytic growth of lung cancer did not show any specific pattern in chromobronchoscopy. However, a specific dye staining was detected in one case where exophytic growth of metastatic colorectal cancer was present in the right upper lobe. In two other cases, a circumscribed staining was noted in unsuspicious mucosa. But histology revealed inflammation only. Conclusions. In contrast to previous studies, the present findings clearly indicate that chromobronchoscopy is not useful for early detection of malignant or premalignant lesions of the central airways.

Evaluation of effective dose from CT scans for overweight and obese adult patients using the VirtualDose software

International Nuclear Information System (INIS)

Liang, Baohui; Gao, Yiming; Chen, Zhi; Xu, X. George

2017-01-01

This paper evaluates effective dose (ED) of overweight and obese patients who undergo body computed tomography (CT) examinations. ED calculations were based on tissue weight factors in the International Commission on Radiological Protection Publication 103 (ICRP 103). ED per unit dose length product (DLP) are reported as a function of the tube voltage, body mass index (BMI) of patient. The VirtualDose software was used to calculate ED for male and female obese phantoms representing normal weight, overweight, obese 1, obese 2 and obese 3 patients. Five anatomic regions (chest, abdomen, pelvis, abdomen/pelvis and chest/abdomen/pelvis) were investigated for each phantom. The conversion factors were computed from the DLP, and then compared with data previously reported by other groups. It was observed that tube voltage and BMI are the major factors that influence conversion factors of obese patients, and that ED computed using ICRP 103 tissue weight factors were 24% higher for a CT chest examination and 21% lower for a CT pelvis examination than the ED using ICRP 60 factors. For body CT scans, increasing the tube voltage from 80 to 140 kVp would increase the conversion factors by as much as 19-54% depending on the patient's BMI. Conversion factor of female patients was ∼7% higher than the factors of male patients. DLP and conversion factors were used to estimate ED, where conversion factors depended on tube voltage, sex, BMI and tissue weight factors. With increasing number of obese individuals, using size-dependence conversion factors will improve accuracy, in estimating patient radiation dose. (authors)

Tracheal rupture

Science.gov (United States)

... that may be done include: Neck CT scan Chest x-ray Bronchoscopy ... People who have had a trauma will need to have their injuries ... who have breathed a foreign body into the airways, bronchoscopy ...

Preoperative staging of esophageal carcinoma with multidetector CT and virtual endoscopy

International Nuclear Information System (INIS)

Onbas, Omer; Eroglu, Atilla; Kantarci, Mecit; Polat, Pinar; Alper, Fatih; Karaoglanoglu, Nurettin; Okur, Adnan

2006-01-01

Purpose: The aim of this study was to assess the accuracy of multidetector computed tomography (MDCT), including virtual endoscopy (VE) for detection, precise localization, preoperative evaluation and staging of esophageal cancer (EC) by comparison with surgical and histopathological findings. Materials and methods: Between September 2003 and April 2005, 44 patients with histologically proven EC underwent MDCT and VE. Among 44 patients, the findings were confirmed in 24 at surgery. The accuracy of three-dimensional MDCT for detection, localization, and staging of EC was determined, and compared with surgical finding and histopathology. Results: The overall accuracy of three-dimensional multidetector row CT for detection of EC was 100% (24/24). MDCT staging was correct in 20 patients (83.3%). The T parameter was correctly assessed in 22 (91.7%) cases (understaged in 1 and overstaged in 1). The N parameter was correctly evaluated in 20 (83.4%) patients (understaged in 2 and overstaged in 2). The overall accuracy of VE for the morphologic classification of EC was 81.5%. Conclusions: Three-dimensional MDCT, along with VE is a promising method for preoperative evaluation and staging of EC. Although accuracy in N staging remains low in comparison to PET, it provides a larger amount of diagnostic and staging information

Clinical application of helical CT colonography

International Nuclear Information System (INIS)

Zeng Huiliang; Zhu Xinjin; Liang Rujian; Liang Jianhao; Ou Weiqian; Wen Haomao

2009-01-01

Objective: To investigate the clinical value of 16-slice helical CT colonography in the diagnosis of colon tumor and polypus. Methods: 16-slice helical CT volumetric scanning was performed in 18 patients with colonic disease, including colonic tumor (n=16) and colonic polypus (n=2). 3D images, virtual endoscopy and multiplanar reformation were obtained in the AW4.1 workstation. CT appearances were compared with operation and fiberoptic colonoscopy. Results: Satisfied results were achieved from 18 patients, no difference found in results between CT colonography and operation in 16 patients with colonic tumor. Conclusion: 16-slice helical CT colonography is of great value in preoperative staging of colonic tumor and have a high value in clinical application. (authors)

Lung abscess following bronchoscopy due to multidrug-resistant Capnocytophaga sputigena adjacent to lung cancer with high PD-L1 expression.

Science.gov (United States)

Migiyama, Yohei; Anai, Moriyasu; Kashiwabara, Kosuke; Tomita, Yusuke; Saeki, Sho; Nakamura, Kazuyoshi; Okamoto, Shinichiro; Ichiyasu, Hidenori; Fujii, Kazuhiko; Kohrogi, Hirotsugu

2018-04-24

Lung abscess following flexible bronchoscopy is a rare and sometimes fatal iatrogenic complication. Here, we report the first case of a lung abscess caused by multidrug-resistant Capnocytophaga sputigena following bronchoscopy. A 67-year-old man underwent bronchoscopy to evaluate a lung mass. Seven days after transbronchial lung biopsy, he presented with an abscess formation in a lung mass. Empirical antibiotic therapy, including with garenoxacin, ampicillin/sulbactam, clindamycin and cefepime, was ineffective. Percutaneous needle aspiration of lung abscess yielded C. sputigena resistant to multiple antibiotics but remained susceptible to carbapenem. He was successfully treated by the combination therapy with surgery and with approximately 6 weeks of intravenous carbapenem. Finally he was diagnosed with a lung abscess with adenocarcinoma expressing high levels of programmed cell death ligand 1. The emergence of multidrug-resistant Capnocytophaga species is a serious concern for effective antimicrobial therapy. Clinicians should consider multidrug-resistant C. sputigena as a causative pathogen of lung abscess when it is refractory to antimicrobial treatment. Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The Effect of Dextromethorphan Premedication on Cough and Patient Tolerance During Flexible Bronchoscopy: A Randomized, Double-blind, Placebo-controlled Trial.

Science.gov (United States)

Amini, Shahideh; Peiman, Soheil; Khatuni, Mahdi; Ghalamkari, Marziyeh; Rahimi, Besharat

2017-10-01

Patients undergoing bronchoscopy can experience problems such as anxiety and cough, requiring various doses of sedatives and analgesics. The purposes of this study were to investigate the effect of premedication with dextromethorphan on patients' cough and anxiety, and the use of analgesics/sedatives during flexible bronchoscopy (FB). A randomized, double-blind, placebo-controlled, prospective study was performed to assess the effect of dextromethorphan premedication on patients who underwent diagnostic bronchoscopy. Seventy patients included in this study were randomly allocated into 2 groups: group A consisted of 35 patients who received dextromethorphan before FB; and group B consisted of 35 patients who received a placebo. A questionnaire was given to the patients and bronchoscopist about perception of cough, anxiety, and discomfort. The amount of sedative medication and lidocaine use during the procedure and the procedure time were recorded. The group that was premedicated with dextromethorphan had lower complaint scores, significantly less coughing, significantly less stress assessed by the patient and the physician evaluation, shorter total procedure time, and fewer midazolam requirements during FB (P-value dextromethorphan premedication is an effective approach to facilitate the performance of FB for the physician, and could improve patient comfort.

Sedation during bronchoscopy: data from a nationwide sedation and monitoring survey.

Science.gov (United States)

Gaisl, Thomas; Bratton, Daniel J; Heuss, Ludwig T; Kohler, Malcolm; Schlatzer, Christian; Zalunardo, Marco P; Frey, Martin; Franzen, Daniel

2016-08-05

There is limited knowledge on practice patterns in procedural sedation and analgesia (PSA), the use of propofol, and monitoring during flexible bronchoscopy (FB). The purpose of this study was to assess the current practice patterns of FBs and to focus on the use of propofol, the education of the proceduralist, and the involvement of anaesthesiologists during FB. An anonymous questionnaire was sent to 299 pulmonologists. Only respondents who were active physicians in adult respiratory medicine performing FB were subsequently analysed. The response rate was 78 % and 27,149 FB in the previous 12 months were analysed. The overall sedation-related morbidity rate was 0.02 % and mortality was 7/100'000 FB. Sedation was used in 95 % of bronchoscopies. The main drugs used for PSA were propofol (77 %) and midazolam (46 %). In 84 % of PSAs propofol was used without the attendance of an anaesthesiologist. The use of propofol was associated with high volume bronchoscopists (p vital parameters has become standard practice, pulmonologists reported a very low rate of systematic basic education and training in the field of PSA (50 %). In Switzerland, PSA during FB is mostly performed with propofol without the attendance of an anaesthesiologist and the use of this drug is expected to increase in the future. While monitoring standards are very high there is need for policies to improve education, systematic training, and support for pulmonologists for PSA during FB.

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

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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

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

International Nuclear Information System (INIS)

Yamada, Yoshitake; Jinzaki, Masahiro; Hosokawa, Takahiro; Tanami, Yutaka; Abe, Takayuki; Kuribayashi, Sachio

2014-01-01

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

CT- and MRI-based volumetry of resected liver specimen: Comparison to intraoperative volume and weight measurements and calculation of conversion factors

International Nuclear Information System (INIS)

Karlo, C.; Reiner, C.S.; Stolzmann, P.; Breitenstein, S.; Marincek, B.; Weishaupt, D.; Frauenfelder, T.

2010-01-01

Objective: To compare virtual volume to intraoperative volume and weight measurements of resected liver specimen and calculate appropriate conversion factors to reach better correlation. Methods: Preoperative (CT-group, n = 30; MRI-group, n = 30) and postoperative MRI (n = 60) imaging was performed in 60 patients undergoing partial liver resection. Intraoperative volume and weight of the resected liver specimen was measured. Virtual volume measurements were performed by two readers (R1,R2) using dedicated software. Conversion factors were calculated. Results: Mean intraoperative resection weight/volume: CT: 855 g/852 mL; MRI: 872 g/860 mL. Virtual resection volume: CT: 960 mL(R1), 982 mL(R2); MRI: 1112 mL(R1), 1115 mL(R2). Strong positive correlation for both readers between intraoperative and virtual measurements, mean of both readers: CT: R = 0.88(volume), R = 0.89(weight); MRI: R = 0.95(volume), R = 0.92(weight). Conversion factors: 0.85(CT), 0.78(MRI). Conclusion: CT- or MRI-based volumetry of resected liver specimen is accurate and recommended for preoperative planning. A conversion of the result is necessary to improve intraoperative and virtual measurement correlation. We found 0.85 for CT- and 0.78 for MRI-based volumetry the most appropriate conversion factors.

Computed Tomographic Virtual Colonoscopy to Screen for Colorectal Neoplasia in asymptomatic adults

International Nuclear Information System (INIS)

Pickhardt, Perry J.; Choi, J Richard; Hwang, Inku and others

2004-01-01

We evaluated the performance characteristics of computed tomographic (CT) virtual colonospy for the detection of colorectal neoplasia in an average-risk screening population. A total of 1233 symptomatic adults (mean age, 57.8 years) underwent same-day virtual and optical colonoscopy. Radiologists used the three-dimensional endoluminal display for the initial detection of polyps on CT virtual colonoscopy. For the initial examination of each colonic segment, the colonoscopists were unaware of the findings on virtual colonoscopy, which were revealed to them before any subsequent reexamination. The sensitivity and specificity of virtual colonoscopy and the sensitivity of optical colonoscopy were calculated with the use of the findings of the final, unblinded optical colonoscopy as the reference standard. The sensitivity of virtual colonoscopy for adenomatous polyps was 93.8 percent for polyps at least 10 mm in diameter, 93.9 percent for polyps at least 8 mm in diameter, and 88.7 percent for polyps at least 6 mm in diameter. The sensitivity of optical colonoscopy for adenomatous polyps was 87.5 percent, 91.5 percent, and 92.3 percent for the three sizes of polyps, respectively. The specificity of virtual colonoscopy for adenomatous polyps was 96.0 percent for polyps at least 10 mm in diameter, 92.2 percent for polyps at least 8 mm in diameter, and 79.6 percent for polyps at least 6 mm in diameter.Two polyps were malignant; both were detected on virtual colonoscopy, and one of them was missed on optical colonoscopy before the results on virtual colonoscopy were revealed. CT virtual colonoscopy with the use of a three-dimensional approach is an accurate screening method for the detection of colorectal neoplasia in symptomatic average-risk adults and compares favorably with optical colonoscopy in terms of the detection of clinically relevant lesions

Virtual simulation. First clinical results in patients with prostate cancer

International Nuclear Information System (INIS)

Buchali, A.; Dinges, S.; Koswig, S.; Rosenthal, P.; Salk, S.; Harder, C.; Schlenger, L.; Budach, V.

1998-01-01

Investigation of options of virtual simulation in patients with localized prostate cancer. Twenty-four patients suffering from prostate cancer were virtual simulated. The clinical target volume was contoured and the planning target volume was defined after CT scan. The isocenter of the planning target volume was determined and marked at patient's skin. The precision of patients marking was controlled with conventional simulation after physical radiation treatment planning. Mean differences of the patient's mark revealed between the 2 simulations in all room axes around 1 mm. The organs at risk were visualized in the digital reconstructed radiographs. The precise patient's mark of the isocentre by virtual simulation allows to skip the conventional simulation. The visualisation of organs at risk leeds to an unnecessarity of an application of contrast medium and to a further relieve of the patient. The personal requirement is not higher in virtual simulation than in conventional CT based radiation treatment planning. (orig./MG) [de

Virtual reality publication of spiral ct-derived three-dimensional models: or, creation of spiral, CT-derived, three-dimensional VRML objects.

Science.gov (United States)

Tyszka, J M

1997-01-01

Three-dimensional models can be generated from slice images, such as those obtained from computed tomography (CT) and magnetic resonance imaging (MRI) using a variety of techniques. A popular method for rendering 3D anatomical models is the creation of polygonal mesh surfaces representing the boundary between tissues. Mesh surfaces can be rendered extremely quickly using conventional personal computers, without recourse to more expensive graphic workstations. The dissemination of three-dimensional (3D) models across the Internet has been made significantly easier by the definition of the Virtual Reality Markup Language (VRML) format. The VRML definition allows the parameters and relationships of 3D objects to be described in a text format. The text file can be transfered from a host computer to a remote client computer through the World Wide Web and viewed using readily available software (See Appendix). VRML is based on the definition of primitive 3D objects such as polygons and spheres. Consequently, the transition from a mesh surface derived from a clinical image data set to a VRML object is relatively simple, allowing for convenient and cost-effective dissemination of 3D clinical models across the internet.

Virtual colonoscopy - changes for screening examination?

International Nuclear Information System (INIS)

Rust, G.F.; Reiser, M.

2002-01-01

In principle, virtual colonoscopy is capable to be used as method for early detection of colorectal cancer (CRC), even if the accuracy of the method and radiation exposure are matters discussion in the radiological community. Virtual colonoscopy is able to detect any pathology which is relevant for early detection of CRC especially when using multislice CT, but also with single slice CT. The diagnosis of small lesions, less than 7 mm in diameter (polyps and flat lesions) is still problematic as it is in conventional colonoscopy. The exposure to x-rays in asymptomatic patients, without any increased risk of developing cancer is highly problematic and should be reduced to a minimum. Using special post processing filters on the volume dataset it can be shown that a tube current of 20 mAs is sufficient without any loss in accuracy. Measurements on the Alderson-phantom showed, that an effective dose exposure of 1.2 mSv is obtained using these reduced mAs values. It has to be differentiated between virtual colonoscopy for early detection of polyps and CRC in individual patients or as a screening examination of a large population. Virtual colonoscopy as a screening examination necessitates reduction of radiation dose, a high degree of automatisation in 3D reconstructions as well as the assessment of the entire mucosa. High risk patients, whom refuse fibreoptic colonoscopy should undergo virtual colonoscopy. Virtual colonoscopy has a good chance to become an accepted tool for general screening, if efficient dose reduction, complete visualization of the colon mucosa and automatisation of the post processing procedures can be achieved. (orig.) [de

Can virtual autopsy with postmortem CT improve clinical diagnosis of cause of death? A retrospective observational cohort study in a Dutch tertiary referral centre

Science.gov (United States)

Sonnemans, Lianne J P; Kubat, Bela; Prokop, Mathias; Klein, Willemijn M

2018-01-01

Objective To investigate whether virtual autopsy with postmortem CT (PMCT) improves clinical diagnosis of the immediate cause of death. Design Retrospective observational cohort study. Inclusion criteria: inhospital and out-of-hospital deaths over the age of 1 year in whom virtual autopsy with PMCT and conventional autopsy were performed. Exclusion criteria: forensic cases, postmortal organ donors and cases with incomplete scanning procedures. Cadavers were examined by virtual autopsy with PMCT prior to conventional autopsy. The clinically determined cause of death was recorded before virtual autopsy and was then adjusted with the findings of virtual autopsy. Using conventional autopsy as reference standard, we investigated the increase in sensitivity for immediate cause of death, type of pathology and anatomical system involved before and after virtual autopsy. Setting Tertiary referral centre. Participants 86 cadavers that underwent conventional and virtual autopsy between July 2012 and June 2016. Intervention PMCT consisted of brain, cervical spine and chest–abdomen–pelvis imaging. Conventional autopsy consisted of thoracoabdominal examination with/without brain autopsy. Primary and secondary outcome measures Increase in sensitivity for the immediate cause of death, type of pathology (infection, haemorrhage, perfusion disorder, other or not assigned) and anatomical system (pulmonary, cardiovascular, gastrointestinal, other or not assigned) involved, before and after virtual autopsy. Results Using PMCT, the sensitivity for immediate cause of death increased with 12% (95% CI 2% to 22%) from 53% (41% to 64%) to 64% (53% to 75%), with 18% (9% to 27%) from 65% (54% to 76%) to 83% (73% to 91%) for type of pathology and with 19% (9% to 30%) from 65% (54% to 76%) to 85% (75% to 92%) for anatomical system. Conclusion While unenhanced PMCT is an insufficient substitute for conventional autopsy, it can improve diagnosis of cause of death over clinical diagnosis alone

Indication for fiberoptic bronchoscopy in HIV-infected patients suspected for Pneumocystis carinii pneumonia

DEFF Research Database (Denmark)

Orholm, M; Lundgren, Jens Dilling; Nielsen, T L

1990-01-01

During a six-month period, 40 consecutive fiberoptic bronchoscopic procedures including bronchoalveolar lavage, bronchial brushing and forceps biopsy were performed in local anaesthesia on 34 HIV-infected males presenting symptoms compatible with Pneumocystis carinii pneumonia. In 23 examinations...... did not differ with regard to history, clinical examination, immunology, serology or chest radiograph. We conclude that fiberoptic bronchoscopy should be performed on wide indications in HIV-infected patients with symptoms compatible with P. carinii pneumonia. The procedure is easily performed...

Computational morphology of the lung and its virtual imaging

International Nuclear Information System (INIS)

Kitaoka, Hiroko

2002-01-01

The author proposes an entirely new approach called 'virtual imaging' of an organ based on 'computational morphology'. Computational morphology describes mathematically design as principles of an organ structure to generate the organ model via computer, which can be called virtual organ. Virtual imaging simulates image data using the virtual organ. The virtual organ is divided into cubic voxels, and the CT value or other intensity value for each voxel is calculated according to the tissue properties within the voxel. The validity of the model is examined by comparing virtual images with clinical images. Computational image analysis methods can be developed based on validated models. In this paper, computational anatomy of the lung and its virtual X-ray imaging are introduced

Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies.

Science.gov (United States)

Hoffman, Heidi; Torres, William E; Ernst, Randy D

2002-01-01

Axial thin-collimation state-of-the-art spiral computed tomography (CT) was combined with sagittal and coronal reformatting, three-dimensional (3D) reconstruction, and virtual "fly-through" techniques to nondestructively study nine Egyptian mummies. These techniques provided important paleopathologic and historical information about mummification techniques, depicted anatomy in the most informative imaging plane, illustrated the soft-tissue preservation and physical appearance of mummies in superb detail, and generated an intriguing virtual tour through hollow mummified remains without harming the specimens themselves. Images generated with these methods can help archaeologists and Egyptologists understand these fascinating members of mankind and can serve as adjunct visual aids for laypersons who are interested in mummies. CT has emerged as the imaging modality of choice for the examination of Egyptian mummies due to its noninvasive cross-sectional nature and inherently superior contrast and spatial resolution. As multi-detector row CT and postprocessing tools evolve, the capabilities and applications of CT will continue to proliferate, attesting to the expanded versatility and utility of CT as a noninvasive research tool in the multidisciplinary study of Egyptian mummies. Copyright RSNA, 2002

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2017-07-01

Jul 1, 2017 ... respondents identified the lack of formal training in the art of bronchoscopy as the foremost challenge facing its ... bronchoscopic training programme is imperative to enhance the trainees' proficiency for the furtherance of ..... A. Evaluation of virtual reality bronchoscopy as a learning and assessment tool.

Low-dose CT: new tool for screening lung cancer?

International Nuclear Information System (INIS)

Diederich, S.; Wormanns, D.; Heindel, W.

2001-01-01

Lung cancer is the leading cause of death from malignant tumours as it is very common and has a poor prognosis at advanced tumour stages. Prognosis could be improved by treatment at early stages. As these stages are usually asymptomatic, a diagnostic test that would allow detection of early tumour stages in a population at risk could potentially reduce mortality from lung cancer. Previous approaches using chest radiography and sputum cytology in smokers have been disappointing. Fluorescent bronchoscopy and molecular markers are not yet applicable in clinical routine. Because of its high sensitivity for small pulmonary nodules, which are the most common manifestation of early lung cancer, CT appears suitable as a screening test. Low-dose examination parameters can and should be used for this purpose. From clinical practice it is well known that chest CT often demonstrates small pulmonary nodules, which do not represent lung cancer. Therefore, non-invasive diagnostic algorithms are required to avoid unnecessary biopsies in benign lesions. In preliminary studies of low-dose CT using algorithms based on size and density of detected nodules a large proportion of asymptomatic lung cancers and a large proportion of early, resectable tumour stages were found with a small proportion of invasive procedures for benign nodules. Before this technology can be recommended for broad application, however, further information is required regarding appropriate inclusion criteria (smoking habits, age groups) and screening intervals. Most importantly, further data are required to clarify whether lung cancer screening using low-dose CT can actually reduce mortality from lung cancer. (orig.)

Mucosal detail at CT virtual reality: surface versus volume rendering.

Science.gov (United States)

Hopper, K D; Iyriboz, A T; Wise, S W; Neuman, J D; Mauger, D T; Kasales, C J

2000-02-01

To evaluate computed tomographic virtual reality with volumetric versus surface rendering. Virtual reality images were reconstructed for 27 normal or pathologic colonic, gastric, or bronchial structures in four ways: the transition zone (a) reconstructed separately from the wall by using volume rendering; (b) with attenuation equal to air; (c) with attenuation equal to wall (soft tissue); (d) with attenuation halfway between air and wall. The four reconstructed images were randomized. Four experienced imagers blinded to the reconstruction graded them from best to worst with predetermined criteria. All readers rated images with the transition zone as a separate structure as overwhelmingly superior (P Virtual reality is best with volume rendering, with the transition zone (mucosa) between the wall and air reconstructed as a separate structure.

Virtual Reality Exploration and Planning for Precision Colorectal Surgery.

Science.gov (United States)

Guerriero, Ludovica; Quero, Giuseppe; Diana, Michele; Soler, Luc; Agnus, Vincent; Marescaux, Jacques; Corcione, Francesco

2018-06-01

Medical software can build a digital clone of the patient with 3-dimensional reconstruction of Digital Imaging and Communication in Medicine images. The virtual clone can be manipulated (rotations, zooms, etc), and the various organs can be selectively displayed or hidden to facilitate a virtual reality preoperative surgical exploration and planning. We present preliminary cases showing the potential interest of virtual reality in colorectal surgery for both cases of diverticular disease and colonic neoplasms. This was a single-center feasibility study. The study was conducted at a tertiary care institution. Two patients underwent a laparoscopic left hemicolectomy for diverticular disease, and 1 patient underwent a laparoscopic right hemicolectomy for cancer. The 3-dimensional virtual models were obtained from preoperative CT scans. The virtual model was used to perform preoperative exploration and planning. Intraoperatively, one of the surgeons was manipulating the virtual reality model, using the touch screen of a tablet, which was interactively displayed to the surgical team. The main outcome was evaluation of the precision of virtual reality in colorectal surgery planning and exploration. In 1 patient undergoing laparoscopic left hemicolectomy, an abnormal origin of the left colic artery beginning as an extremely short common trunk from the inferior mesenteric artery was clearly seen in the virtual reality model. This finding was missed by the radiologist on CT scan. The precise identification of this vascular variant granted a safe and adequate surgery. In the remaining cases, the virtual reality model helped to precisely estimate the vascular anatomy, providing key landmarks for a safer dissection. A larger sample size would be necessary to definitively assess the efficacy of virtual reality in colorectal surgery. Virtual reality can provide an enhanced understanding of crucial anatomical details, both preoperatively and intraoperatively, which could

Diagnostic accuracy of virtual non-contrast enhanced dual-energy CT for diagnosis of adrenal adenoma: A systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Connolly, Michael J.; McInnes, Matthew D.F.; Schieda, Nicola [University of Ottawa Department of Radiology, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON (United States); El-Khodary, Mohamed [McMaster University Department of Radiology, Hamilton, ON (Canada); McGrath, Trevor A. [University of Ottawa, Faculty of Medicine, Ottawa, Ontario (Canada)

2017-10-15

To compare the diagnostic accuracy of dual-energy (DE) virtual non-contrast computed tomography (vNCT) to non-contrast CT (NCT) for the diagnosis of adrenal adenomas. Search of multiple databases and grey literature was performed. Two reviewers independently applied inclusion criteria and extracted data. Risk of bias was assessed using QUADAS-2. Summary estimates of diagnostic accuracy were generated and sources of heterogeneity were assessed. Five studies (170 patients; 192 adrenal masses) were included for diagnostic accuracy assessment; all used dual-source dual-energy CT. Pooled sensitivity for adrenal adenoma on vNCT was 54% (95% CI: 47-62%). Pooled sensitivity for NCT was 57% (95% CI: 45-69%). Pooling of specificity was not performed since no false positives were reported. There was a trend for overestimation of HU density on vNCT as compared to NCT which appeared related to contrast timing. Potential sources of bias were seen regarding the index test and reference standard for the included studies. Potential sources of heterogeneity between studies were seen in adenoma prevalence and intravenous contrast timing. vNCT images generated from dual-energy CT demonstrated comparable sensitivity to NCT for the diagnosis of adenomas; however the included studies are heterogeneous and at high risk for some types of bias. (orig.)

Virtual Cystoscopy

International Nuclear Information System (INIS)

Mejia Restrepo, Jorge; Aldana S, Natalia; Munoz Sierra, Juan; Lopez Amaya, Juan

2011-01-01

Introduction: virtual cystoscopy is a minimally invasive procedure that facilitates the evaluation of the urinary tract, allowing intraluminal navigation through the urinary tract structures on the basis of CT imaging reconstructions. it allows detection of various pathologies of the system, through high-sensitivity, three-dimensional lesion visualization with some advantages over conventional cystoscopy. Objective: to describe the technique used for virtual cystoscopy at our institution,and present some representative cases. Materials and methods: We describe the main indications, advantages and limitations of the method, followed by a description of the technique used in our institution, and finally, we present five representative cases of bladder and urethral pathology. Conclusion: virtual cystoscopy is a sensitive technique for the diagnosis of bladder tumors, even those smaller than 5mm. it is the preferred method in patients who have contraindications for conventional cystoscopy, such as prostate hyperplasia, urethral stenoses and active haematuria.it is less invasive and has a lower complication rate when compared with conventional cystoscopy. It has limited use in the assessment of the mucosa and of small, flat lesions.

COMPARISON STUDY OF COUGH SUPPRESSION DURING FLEXIBLE BRONCHOSCOPY USING LOCAL ANAESTHESIA IN DIFFERENT TECHNIQUES- (10% LIGNOCAINE SPRAY + 2% LIGNOCAINE AS YOU GO VERSUS (4% LIGNOCAINE NEBULISATION + 2% LIGNOCAINE AS YOU GO

Directory of Open Access Journals (Sweden)

Koushik Muthu Raja Mathivanan

2017-08-01

Full Text Available BACKGROUND Anaesthesia for bronchoscopy poses unique challenges for the pulmonologist. By definition, bronchoscopy is an endoscopic technique to visualise the inside of the airways, it is a pivotal diagnostic and therapeutic tool in Pulmonary Medicine. Rigid bronchoscopy is usually done for diagnosis and treatment of intra and/or extra luminal obstruction in the airway for adults and children. With the development of fibreoptic and advanced electronic technology, the flexible bronchoscope has replaced the rigid bronchoscope for most diagnostic and some therapeutic indications. Rigid bronchoscopy requires general anaesthesia, however, flexible bronchoscopy can be performed with conscious sedation supplemented with local anaesthesia. The aim of the study is to- 1. Assess the effect of local anaesthesia on cough suppression during flexible bronchoscopy, when given by two different methods. 2. Compare the degree of cough and patient comfort while using “10% lignocaine spray + 2% lignocaine as you go technique, versus 4% lignocaine nebulisation + 2% lignocaine as you go technique.” MATERIALS AND METHODS It is a prospective study done on 50 consecutive patients undergoing diagnostic flexible bronchoscopy from December 2016 to February 2017. The study groups were assembled by block randomisation technique to receive lignocaine (local anaesthesia as either “as you go” and “spray” or “as you go” and “nebulisation”. Institutional Ethics Committee clearance was obtained prior to commencement of the study. RESULTS The study involving 50 patients and statistical analysis illustrated that in 2% lignocaine as you go + 10% lignocaine spray “no cough” and “mild cough” is 18 out of sample 25, which is 72%. Hence, “10% lignocaine spray + 2% lignocaine as you go” is better than “4% lignocaine nebulisation + 2% lignocaine as you go” technique. There was no significant arrhythmias in any of the patients. The dose of lidocaine is

Spirometer-controlled Cine-Magnetic Resonance Imaging for Diagnosis of Tracheobronchomalacia in Pediatric Patients

NARCIS (Netherlands)

Ciet, P.; Wielopolski, P.; Manniesing, R.; Lever, S.; Bruijne, M. de; Morana, G.; Muzzio, P.C.; Lequin, M.H.; Tiddens, H.A.W.M.

2014-01-01

Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children is

Repeated Bronchoscopy - Treatment of Severe Respiratory Failure in a Fire Victim

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Petris Ovidiu Rusalim

2017-10-01

Full Text Available A case of respiratory failure in a domestic fire victim presenting with 1-3-degree skin burns on 10% of the total body surface, is reported. Forty-eight hours after admission to hospital, the patient developed severe respiratory failure that did not respond to mechanical ventilation. Severe obstruction of the airway had resulted from secretions and deposits of soot forming bronchial casts. The patient required repeated bronchoscopies to separate and remove the bronchial secretions and soot deposits. An emergency bronchial endoscopic exam was crucial in the patient’s survival and management. The patient was discharged from the hospital after twenty-four days.

Fibreoptic bronchoscopy without sedation: Is transcricoid injection better than the "spray as you go" technique?

Directory of Open Access Journals (Sweden)

Alka Chandra

2011-01-01

Full Text Available Aim: The aim of the study was to compare transcricoid injection with "spray as you go" technique for diagnostic fibreoptic bronchoscopy, to perform the procedure without sedation and to record any complication or side effects. Methods: Sixty patients belonging to the age group 20-70 years, undergoing diagnostic bronchoscopy over a period of 6 months, were randomly selected and divided into two groups alternatively to receive 3 ml of 4% lignocaine by a single transcricoid puncture (group I or 2 ml of 4% lignocaine instilled through the bronchoscope on to the vocal cords and further 1 ml of 2% lignocaine into each main bronchus (group II. Additional dose of lignocaine as required was given in both the groups. All patients were given intramuscular atropine 0.6 mg, 20 min before the procedure. Nebulisation with 3 ml of 4% lignocaine was given to all patients. The time from nasal insertion of the bronchoscope to reach the carina was recorded, and the total dose of lignocaine required in both the groups was calculated and compared. The cough episodes during the procedure, systolic blood pressure, and pulse rate were compared before the procedure and 5 min after the procedure in both the groups. A 0-10 visual analogue scale (VAS was used to assess discomfort 30 min after the procedure. Results: The time to reach carina was more in group II (P<0.02, and cough episodes were also more in group II (P<0.05 than in group I. The vitals before the procedure were comparable in both the groups, but 5 min after the procedure the vitals were more stable in group I than in group II, and the total dose of lignocaine required in group II was more than in group I (P<0.001. However, the VAS score was comparable in both the groups. Conclusion: Transcricoid puncture for diagnostic bronchoscopies without sedation was associated with no complication and discomfort and required lesser dose of local anaesthetic with more stable vitals and good conditions for bronchoscopists.

Spiral CT pneumocolon: applications, status and limitations

International Nuclear Information System (INIS)

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. (orig.)

Spirometer-controlled cine magnetic resonance imaging used to diagnose tracheobronchomalacia in paediatric patients.

Science.gov (United States)

Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra; Lever, Sandra; de Bruijne, Marleen; Morana, Giovanni; Muzzio, Pier Carlo; Lequin, Maarten H; Tiddens, Harm A W M

2014-01-01

Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard for diagnosing TBM; however it has major disadvantages, such as general anaesthesia. Cine computed tomography (CT) is a noninvasive alternative used to diagnose TBM, but its use in children is restricted by ionising radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine magnetic resonance imaging (MRI) as an alternative to cine-CT in a retrospective study. 12 children with a mean age (range) of 12 years (7-17 years), suspected of having TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration covering the thorax using a three-dimensional spoiled gradient echo sequence. Three-dimensional dynamic scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter >50% at end-expiration in the static and dynamic scans. The success rate of the cine-MRI protocol was 92%. Cine-MRI was compared with bronchoscopy or chest CT in seven subjects. TBM was diagnosed by cine-MRI in seven (58%) out of 12 children and was confirmed by bronchoscopy or CT. In four patients, cine-MRI demonstrated tracheal narrowing that was not present in the static scans. Spirometer controlled cine-MRI is a promising technique to assess TBM in children and has the potential to replace bronchoscopy.

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

International Nuclear Information System (INIS)

Sorensen, J; Duran, C; Stingo, F; Wei, W; Rao, A; Zhang, L; Court, L; Erasmus, J; Godoy, M

2015-01-01

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

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

64-Row multidetector CT virtual hysterosalpingography. Findings in 2500 patients

International Nuclear Information System (INIS)

Carrascosa, Patricia; Capunay, Carlos; Baronio, Mariano; Vallejos, Javier; Papier, Sergio; Carrascosa, Jorge

2011-01-01

Objective. To depict typical features of virtual hysterosalpingography (VHSG) in infertile patients. Material and methods: 2500 VHSG performed using a 64-row MOCT were evaluated. Results: Cervical abnormalities visualized corresponded to parietal irregularities (21%); thickened folds (9%); polyps (11%); diverticula (5%); cervical strictures (8%), and synechiae (1.5%). At the level of uterine cavity, polyps (44%); submucous myomas (8%); intramural and subserosal fibroids (11%); synechiae (10%); malformations (10%); adenomyosis (4%), and cesarean section scar (3%). Unilateral hydrosalpinx (7%) and bilateral hydrosalpinx (2%). Tubal obstruction was reported in 6% of cases. The average radiation dose was 0.94 mSv. Eighty-four percent of the patients reported mild pain or no postoperative discomfort. Conclusions: The virtual hysterosalpingography allowed a proper assessment of the internal genital organs, providing useful diagnostic information on infertility and other gynecological disorders. It constitutes a virtually painless, low-dose radiation technique, besides being well tolerated by patients

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

International Nuclear Information System (INIS)

Karcaaltincaba, M.; Karaosmanoglu, D.; Akata, D.; Sentuerk, S.; Oezmen, M.; Alibek, S.

2009-01-01

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.)

The geometrical precision of virtual bone models derived from clinical computed tomography data for forensic anthropology.

Science.gov (United States)

Colman, Kerri L; Dobbe, Johannes G G; Stull, Kyra E; Ruijter, Jan M; Oostra, Roelof-Jan; van Rijn, Rick R; van der Merwe, Alie E; de Boer, Hans H; Streekstra, Geert J

2017-07-01

Almost all European countries lack contemporary skeletal collections for the development and validation of forensic anthropological methods. Furthermore, legal, ethical and practical considerations hinder the development of skeletal collections. A virtual skeletal database derived from clinical computed tomography (CT) scans provides a potential solution. However, clinical CT scans are typically generated with varying settings. This study investigates the effects of image segmentation and varying imaging conditions on the precision of virtual modelled pelves. An adult human cadaver was scanned using varying imaging conditions, such as scanner type and standard patient scanning protocol, slice thickness and exposure level. The pelvis was segmented from the various CT images resulting in virtually modelled pelves. The precision of the virtual modelling was determined per polygon mesh point. The fraction of mesh points resulting in point-to-point distance variations of 2 mm or less (95% confidence interval (CI)) was reported. Colour mapping was used to visualise modelling variability. At almost all (>97%) locations across the pelvis, the point-to-point distance variation is less than 2 mm (CI = 95%). In >91% of the locations, the point-to-point distance variation was less than 1 mm (CI = 95%). This indicates that the geometric variability of the virtual pelvis as a result of segmentation and imaging conditions rarely exceeds the generally accepted linear error of 2 mm. Colour mapping shows that areas with large variability are predominantly joint surfaces. Therefore, results indicate that segmented bone elements from patient-derived CT scans are a sufficiently precise source for creating a virtual skeletal database.

Virtual computed tomography colonoscopy: artifacts, image quality and radiation dose load in a cadaver study

International Nuclear Information System (INIS)

Springer, P.; Stoehr, B.; Giacomuzzi, S.M.; Bodner, G.; Jaschke, W.; Nedden, D. zur; Klingler, A.

2000-01-01

The purpose of our study was to evaluate the interdependency of spatial resolution, image reconstruction artifacts, and radiation doses in virtual CT colonoscopy by comparing various CT scanning protocols. A pig's colon with several artificial polypoid lesions was imaged after air insufflation with helical CT scanning using 1-, 3-, and 5-mm collimation, and pitch values varying from 1.0 to 3.0. Virtual endoscopic images and ''fly through'' sequences were calculated on a Sun Sparc 20 workstation (Navigator Software, GE Medical Systems, Milwaukee, Wis.). Several reconstruction artifacts as well as overall image quality were evaluated by three independent reviewers. In addition, radiation doses for the different CT protocols were measured as multiple-scan average dose using a 10-cm ion chamber and a standard Plexiglass body phantom. Generally, image quality and reconstruction artifacts were less affected by pitch values than by beam collimation. Thus, narrow beam collimation at higher pitch values (e. g. 3 mm/2.0) seems to be a reasonable compromise between quality of virtual endoscopic images and radiation dose load. (orig.)

Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

Science.gov (United States)

Tang, Xiangyang; Yang, Yi; Tang, Shaojie

2013-03-01

Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

Can virtual autopsy with postmortem CT improve clinical diagnosis of cause of death? A retrospective observational cohort study in a Dutch tertiary referral centre.

Science.gov (United States)

Sonnemans, Lianne J P; Kubat, Bela; Prokop, Mathias; Klein, Willemijn M

2018-03-16

To investigate whether virtual autopsy with postmortem CT (PMCT) improves clinical diagnosis of the immediate cause of death. Retrospective observational cohort study. inhospital and out-of-hospital deaths over the age of 1 year in whom virtual autopsy with PMCT and conventional autopsy were performed. forensic cases, postmortal organ donors and cases with incomplete scanning procedures. Cadavers were examined by virtual autopsy with PMCT prior to conventional autopsy. The clinically determined cause of death was recorded before virtual autopsy and was then adjusted with the findings of virtual autopsy. Using conventional autopsy as reference standard, we investigated the increase in sensitivity for immediate cause of death, type of pathology and anatomical system involved before and after virtual autopsy. Tertiary referral centre. 86 cadavers that underwent conventional and virtual autopsy between July 2012 and June 2016. PMCT consisted of brain, cervical spine and chest-abdomen-pelvis imaging. Conventional autopsy consisted of thoracoabdominal examination with/without brain autopsy. Increase in sensitivity for the immediate cause of death, type of pathology (infection, haemorrhage, perfusion disorder, other or not assigned) and anatomical system (pulmonary, cardiovascular, gastrointestinal, other or not assigned) involved, before and after virtual autopsy. Using PMCT, the sensitivity for immediate cause of death increased with 12% (95% CI 2% to 22%) from 53% (41% to 64%) to 64% (53% to 75%), with 18% (9% to 27%) from 65% (54% to 76%) to 83% (73% to 91%) for type of pathology and with 19% (9% to 30%) from 65% (54% to 76%) to 85% (75% to 92%) for anatomical system. While unenhanced PMCT is an insufficient substitute for conventional autopsy, it can improve diagnosis of cause of death over clinical diagnosis alone and should therefore be considered whenever autopsy is not performed. © Article author(s) (or their employer(s) unless otherwise stated in the text of

Real-time CT-video registration for continuous endoscopic guidance

Science.gov (United States)

Merritt, Scott A.; Rai, Lav; Higgins, William E.

2006-03-01

Previous research has shown that CT-image-based guidance could be useful for the bronchoscopic assessment of lung cancer. This research drew upon the registration of bronchoscopic video images to CT-based endoluminal renderings of the airway tree. The proposed methods either were restricted to discrete single-frame registration, which took several seconds to complete, or required non-real-time buffering and processing of video sequences. We have devised a fast 2D/3D image registration method that performs single-frame CT-Video registration in under 1/15th of a second. This allows the method to be used for real-time registration at full video frame rates without significantly altering the physician's behavior. The method achieves its speed through a gradient-based optimization method that allows most of the computation to be performed off-line. During live registration, the optimization iteratively steps toward the locally optimal viewpoint at which a CT-based endoluminal view is most similar to a current bronchoscopic video frame. After an initial registration to begin the process (generally done in the trachea for bronchoscopy), subsequent registrations are performed in real-time on each incoming video frame. As each new bronchoscopic video frame becomes available, the current optimization is initialized using the previous frame's optimization result, allowing continuous guidance to proceed without manual re-initialization. Tests were performed using both synthetic and pre-recorded bronchoscopic video. The results show that the method is robust to initialization errors, that registration accuracy is high, and that continuous registration can proceed on real-time video at >15 frames per sec. with minimal user-intervention.

Implementation of 3D-virtual brachytherapy in the management of breast cancer: a description of a new method of interstitial brachytherapy

International Nuclear Information System (INIS)

Vicini, Frank A.; Jaffray, David A.; Horwitz, Eric M.; Edmundson, Gregory K.; DeBiose, David A.; Kini, Vijay R.; Martinez, Alvaro A.

1998-01-01

Purpose: We present the initial description of a new technique of interstitial breast brachytherapy in which a computer-generated image of an implant template is applied virtually to serial-computed tomography (CT) scan images of a patient's breast. Optimal placement of the virtual template around the CT images of the proposed target volume provides the physician with a preplan for improved positioning of implant needles around the actual target volume intraoperatively. Methods and Materials: Since March of 1993, 110 patients with early-stage breast cancer were entered onto a protocol of low or high dose rate brachytherapy as the sole radiation modality for part of their breast-conserving therapy. To improve the accuracy and reproducibility of target volume coverage in patients with a closed lumpectomy cavity, 11 of these implants were performed using the virtual brachytherapy technique. The virtual implant procedure was performed by first placing radiopaque skin markers on the breast surface for reference on the CT image and ultimately as intraoperative landmarks for the placement of implant needles. A CT scan of the breast was then performed and the target volume outlined on each CT scan slice by the physician. A virtual image of the brachytherapy template was then positioned around the CT image of the target volume to achieve an idealized implant with optimal coverage. The projected entrance and exit points of all needles on the skin of the breast (from the idealized virtual implant) were then identified (by perspective rendering of multiple 3D views) and hard-copy images taken to the operating room. The implant was then constructed by referencing the virtual implant images (needle entrance and exit points) to the radiopaque skin markers on the breast. After the implant was completed, a CT scan of the breast with the template catheters or needles in position was taken for comparison of the actual target volume coverage with the virtual implant generated

Dual-energy CT and ceramic or titanium prostheses material reduce CT artifacts and provide superior image quality of total knee arthroplasty.

Science.gov (United States)

Kasparek, Maximilian F; Töpker, Michael; Lazar, Mathias; Weber, Michael; Kasparek, Michael; Mang, Thomas; Apfaltrer, Paul; Kubista, Bernd; Windhager, Reinhard; Ringl, Helmut

2018-06-07

To evaluate the influence of different scan parameters for single-energy CT and dual-energy CT, as well as the impact of different material used in a TKA prosthesis on image quality and the extent of metal artifacts. Eight pairs of TKA prostheses from different vendors were examined in a phantom set-up. Each pair consisted of a conventional CoCr prosthesis and the corresponding anti-allergic prosthesis (full titanium, ceramic, or ceramic-coated) from the same vendor. Nine different (seven dual-energy CT and two single-energy CT) scan protocols with different characteristics were used to determine the most suitable CT protocol for TKA imaging. Quantitative image analysis included assessment of blooming artifacts (metal implants appear thicker on CT than they are, given as virtual growth in mm in this paper) and streak artifacts (thick dark lines around metal). Qualitative image analysis was used to investigate the bone-prosthesis interface. The full titanium prosthesis and full ceramic knee showed significantly fewer blooming artifacts compared to the standard CoCr prosthesis (mean virtual growth 0.6-2.2 mm compared to 2.9-4.6 mm, p energy CT protocols showed less blooming (range 3.3-3.8 mm) compared to single-energy protocols (4.6-5.5 mm). The full titanium and full ceramic prostheses showed significantly fewer streak artifacts (mean standard deviation 77-86 Hounsfield unit (HU)) compared to the standard CoCr prosthesis (277-334 HU, p energy CT protocols had fewer metal streak artifacts (215-296 HU compared to single-energy CT protocols (392-497 HU)). Full titanium and ceramic prostheses were ranked superior with regard to the image quality at the bone/prosthesis interface compared to a standard CoCr prosthesis, and all dual-energy CT protocols were ranked better than single-energy protocols. Dual-energy CT and ceramic or titanium prostheses reduce CT artifacts and provide superior image quality of total knee arthroplasty at the bone/prosthesis interface

Impact of multidetector CT-angiography on the emergency management of severe hemoptysis

Energy Technology Data Exchange (ETDEWEB)

Chalumeau-Lemoine, Ludivine [Service de Pneumologie et Réanimation, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France); Khalil, Antoine, E-mail: antoine_khalil@yahoo.fr [Service de Radiologie, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France); Pathological Angiogenesis and Vessel Normalization, Center for Interdisciplinary Research in Biology, CNRS UMR 7241/INSERM U1050, Collège de France, Paris (France); Prigent, Hélène [Service de Pneumologie et Réanimation, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France); Carette, Marie-France [Service de Radiologie, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France); Université Pierre et Marie Curie, Paris VI (France); Fartoukh, Muriel [Service de Pneumologie et Réanimation, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France); Université Pierre et Marie Curie, Paris VI (France); Parrot, Antoine [Service de Pneumologie et Réanimation, Hôpital Tenon, HUEP, APHP, 4 rue de la Chine, 75020 Paris (France)

2013-11-01

Background: Multidetector CT-angiography (MDCTA) is commonly used in patients with severe haemoptysis requiring admission to intensive care unit. However, the impact of MDCTA on the management of severe haemoptysis in emergency setting is poorly evaluated. Methods: We prospectively compared data provided by clinical bedside evaluation (clinical examination, chest-X-ray and fiberoptic bronchoscopy) to MDCTA data in terms of lateralization, location of the bleeding site, etiology as well as impact on the treatment choice. Results: Over a 13-month period, 87 patients (men n = 58, median age = 61 years, median haemoptysis expectorated volume = 180 mL) were included. Etiology was mainly (67%) bronchiectasis, tuberculosis sequelae and tumor. MDCTA and clinical bedside evaluation were equally effective in determining lateralization (87.4% and 93.1%, respectively, p = 0.23) and location (85% and 82.7%, respectively, p = 0.82) of the bleeding site. MDCTA was significantly more accurate than the clinical bedside strategy in determining the haemoptysis cause (86% and 70%, respectively, p = 0.007). Moreover, MDCTA suggested the involvement of systemic arteries as bleeding mechanism in 92% of cases, leading to the modification of the treatment initially considered after bedside evaluation in 21.8% of patients. Conclusion: MDCTA provides useful information for the management of patients with severe haemoptysis, especially in the treatment choice. Thus, in the absence of emergency fiberoptic bronchoscopy (FOB) requirement for airways management, MDCTA should be the first-line procedure performed in emergency clinical setting.

Impact of multidetector CT-angiography on the emergency management of severe hemoptysis

International Nuclear Information System (INIS)

Chalumeau-Lemoine, Ludivine; Khalil, Antoine; Prigent, Hélène; Carette, Marie-France; Fartoukh, Muriel; Parrot, Antoine

2013-01-01

Background: Multidetector CT-angiography (MDCTA) is commonly used in patients with severe haemoptysis requiring admission to intensive care unit. However, the impact of MDCTA on the management of severe haemoptysis in emergency setting is poorly evaluated. Methods: We prospectively compared data provided by clinical bedside evaluation (clinical examination, chest-X-ray and fiberoptic bronchoscopy) to MDCTA data in terms of lateralization, location of the bleeding site, etiology as well as impact on the treatment choice. Results: Over a 13-month period, 87 patients (men n = 58, median age = 61 years, median haemoptysis expectorated volume = 180 mL) were included. Etiology was mainly (67%) bronchiectasis, tuberculosis sequelae and tumor. MDCTA and clinical bedside evaluation were equally effective in determining lateralization (87.4% and 93.1%, respectively, p = 0.23) and location (85% and 82.7%, respectively, p = 0.82) of the bleeding site. MDCTA was significantly more accurate than the clinical bedside strategy in determining the haemoptysis cause (86% and 70%, respectively, p = 0.007). Moreover, MDCTA suggested the involvement of systemic arteries as bleeding mechanism in 92% of cases, leading to the modification of the treatment initially considered after bedside evaluation in 21.8% of patients. Conclusion: MDCTA provides useful information for the management of patients with severe haemoptysis, especially in the treatment choice. Thus, in the absence of emergency fiberoptic bronchoscopy (FOB) requirement for airways management, MDCTA should be the first-line procedure performed in emergency clinical setting

Therapeutic bronchoscopy vs. standard of care in acute respiratory failure

DEFF Research Database (Denmark)

Ellekjaer, K L; Meyhoff, T S; Møller, M H

2017-01-01

) according to the Cochrane Handbook and GRADE methodology, including a predefined protocol (PROSPERO no. CRD42016046235). We included randomized clinical trials (RCTs) comparing therapeutic bronchoscopy to standard of care in critically ill patients with ARF. Two reviewers independently assessed trials...... for inclusion, extracted data and assessed risk of bias. Risk ratios (RR) with 95% confidence intervals (CI) were estimated by conventional meta-analysis. The risk of random errors was assessed by TSA. Exclusively patient-important outcomes were evaluated. RESULTS: We included five trials (n = 212); all were....... A shorter duration of mechanical ventilation was suggested by conventional meta-analysis, however TSA highlighted that only 42% of the required information size had been accrued, indicating high risk of random errors. No trials reported data on adverse events, hospital length of stay, quality of life...

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

International Nuclear Information System (INIS)

Sun, Hao; Hou, Xin-Yi; Xue, Hua-Dan; Li, Xiao-Guang; Jin, Zheng-Yu; Qian, Jia-Ming; Yu, Jian-Chun; Zhu, Hua-Dong

2015-01-01

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

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

Multidetector CT and MRI in diseases of the GI tract

International Nuclear Information System (INIS)

Bruel, J.M.; Gallix, B.

2003-01-01

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)

Virtual reality in advanced medical immersive imaging: a workflow for introducing virtual reality as a supporting tool in medical imaging

KAUST Repository

Knodel, Markus M.

2018-02-27

Radiologic evaluation of images from computed tomography (CT) or magnetic resonance imaging for diagnostic purposes is based on the analysis of single slices, occasionally supplementing this information with 3D reconstructions as well as surface or volume rendered images. However, due to the complexity of anatomical or pathological structures in biomedical imaging, innovative visualization techniques are required to display morphological characteristics three dimensionally. Virtual reality is a modern tool of representing visual data, The observer has the impression of being “inside” a virtual surrounding, which is referred to as immersive imaging. Such techniques are currently being used in technical applications, e.g. in the automobile industry. Our aim is to introduce a workflow realized within one simple program which processes common image stacks from CT, produces 3D volume and surface reconstruction and rendering, and finally includes the data into a virtual reality device equipped with a motion head tracking cave automatic virtual environment system. Such techniques have the potential to augment the possibilities in non-invasive medical imaging, e.g. for surgical planning or educational purposes to add another dimension for advanced understanding of complex anatomical and pathological structures. To this end, the reconstructions are based on advanced mathematical techniques and the corresponding grids which we can export are intended to form the basis for simulations of mathematical models of the pathogenesis of different diseases.

A computer-simulated liver phantom (virtual liver phantom) for multidetector computed tomography evaluation

Energy Technology Data Exchange (ETDEWEB)

Funama, Yoshinori [Kumamoto University, Department of Radiological Sciences, School of Health Sciences, Kumamoto (Japan); Awai, Kazuo; Nakayama, Yoshiharu; Liu, Da; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Miyazaki, Osamu; Goto, Taiga [Hitachi Medical Corporation, Tokyo (Japan); Hori, Shinichi [Gate Tower Institute of Image Guided Therapy, Osaka (Japan)

2006-04-15

The purpose of study was to develop a computer-simulated liver phantom for hepatic CT studies. A computer-simulated liver phantom was mathematically constructed on a computer workstation. The computer-simulated phantom was calibrated using real CT images acquired by an actual four-detector CT. We added an inhomogeneous texture to the simulated liver by referring to CT images of chronically damaged human livers. The mean CT number of the simulated liver was 60 HU and we added numerous 5-to 10-mm structures with 60{+-}10 HU/mm. To mimic liver tumors we added nodules measuring 8, 10, and 12 mm in diameter with CT numbers of 60{+-}10, 60{+-}15, and 60{+-}20 HU. Five radiologists visually evaluated similarity of the texture of the computer-simulated liver phantom and a real human liver to confirm the appropriateness of the virtual liver images using a five-point scale. The total score was 44 in two radiologists, and 42, 41, and 39 in one radiologist each. They evaluated that the textures of virtual liver were comparable to those of human liver. Our computer-simulated liver phantom is a promising tool for the evaluation of the image quality and diagnostic performance of hepatic CT imaging. (orig.)

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography.

Science.gov (United States)

Liu, Xiujuan; Tao, Haiquan; Xiao, Xigang; Guo, Binbin; Xu, Shangcai; Sun, Na; Li, Maotong; Xie, Li; Wu, Changjun

2018-07-01

This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging. Copyright © 2018 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Ai, Songtao; Qu, Mingliang; Glazebrook, Katrina N.; Liu, Yu; Leng, Shuai; McCollough, Cynthia H.; Rhee, Peter C.

2014-01-01

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.)

Spirometer-controlled cine magnetic resonance imaging to diagnose tracheobronchomalacia in pediatric patients

DEFF Research Database (Denmark)

Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra

2014-01-01

is restricted by ionizing radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine-MRI as alternative to cine-CT in a retrospective study.12 children (mean 12 years, range 7-17), suspected to have TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration......Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children...

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...

SU-E-J-94: Geometric and Dosimetric Evaluation of Deformation Image Registration Algorithms Using Virtual Phantoms Generated From Patients with Lung Cancer

International Nuclear Information System (INIS)

Shen, Z; Greskovich, J; Xia, P; Bzdusek, K

2015-01-01

Purpose: To generate virtual phantoms with clinically relevant deformation and use them to objectively evaluate geometric and dosimetric uncertainties of deformable image registration (DIR) algorithms. Methods: Ten lung cancer patients undergoing adaptive 3DCRT planning were selected. For each patient, a pair of planning CT (pCT) and replanning CT (rCT) were used as the basis for virtual phantom generation. Manually adjusted meshes were created for selected ROIs (e.g. PTV, lungs, spinal cord, esophagus, and heart) on pCT and rCT. The mesh vertices were input into a thin-plate spline algorithm to generate a reference displacement vector field (DVF). The reference DVF was used to deform pCT to generate a simulated replanning CT (srCT) that was closely matched to rCT. Three DIR algorithms (Demons, B-Spline, and intensity-based) were applied to these ten virtual phantoms. The images, ROIs, and doses were mapped from pCT to srCT using the DVFs computed by these three DIRs and compared to those mapped using the reference DVF. Results: The average Dice coefficients for selected ROIs were from 0.85 to 0.96 for Demons, from 0.86 to 0.97 for intensity-based, and from 0.76 to 0.95 for B-Spline. The average Hausdorff distances for selected ROIs were from 2.2 to 5.4 mm for Demons, from 2.3 to 6.8 mm for intensity-based, and from 2.4 to 11.4 mm for B-Spline. The average absolute dose errors for selected ROIs were from 0.2 to 0.6 Gy for Demons, from 0.1 to 0.5 Gy for intensity-based, and from 0.5 to 1.5 Gy for B-Spline. Conclusion: Virtual phantoms were modeled after patients with lung cancer and were clinically relevant for adaptive radiotherapy treatment replanning. Virtual phantoms with known DVFs serve as references and can provide a fair comparison when evaluating different DIRs. Demons and intensity-based DIRs were shown to have smaller geometric and dosimetric uncertainties than B-Spline. Z Shen: None; K Bzdusek: an employee of Philips Healthcare; J Greskovich: None; P Xia

Initial experience with AcQsim CT simulator

International Nuclear Information System (INIS)

Michalski, Jeff M.; Gerber, Russell; Bosch, Walter R.; Harms, William; Matthews, John W.; Purdy, James A.; Perez, Carlos A.

1995-01-01

Purpose: We recently replaced our university developed CT simulator prototype with a commercial grade spiral CT simulator (Picker AcQsim) that is networked with three independent virtual simulation workstations and our 3D radiation therapy planning (3D-RTP) system multiple workstations. This presentation will report our initial experience with this CT simulation device and define criteria for optimum clinical use as well as describe some potential drawbacks of the current system. Methods and Materials: Over a 10 month period, 210 patients underwent CT simulation using the AcQsim. An additional 127 patients had a volumetric CT scan done on the device with their CT data and target and normal tissue contours ultimately transferred to our 3D-RTP system. We currently perform the initial patient localization and immobilization in the CT simulation suite by using CT topograms and a fiducial laser marking system. Immobilization devices, required for all patients undergoing CT simulation, are constructed and registered to a device that defines the treatment table coordinates. Orthogonal anterior and lateral CT topograms document patient alignment and the position of a reference coordinate center. The volumetric CT scan with appropriate CT contrast materials administered is obtained while the patient is in the immobilization device. On average, more than 100 CT slices are obtained per study. Contours defining tumor, target, and normal tissues are drawn on a slice by slice basis. Isocenter definition can be automatically defined within the target volume and marked on the patient and immobilization device before leaving the initial CT simulation session. Virtual simulation is then performed on the patient data set with the assistance of predefined target volumes and normal tissue contours displayed on rapidly computed digital reconstructed radiographs (DRRs) in a manner similar to a conventional fluoroscopic radiotherapy simulator. Lastly, a verification simulation is

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.

Implementation of virtual simulation with a wide-bore multislice helcalct scanner

International Nuclear Information System (INIS)

Greer, P.; Kenny, J.

2004-01-01

Full text: Multislice large-bore CT scanners specifically designed for radiotherapy have very recently become available. The issues relating to these type of scanners in radiotherapy and the implementation of virtual simulation are therefore of much current interest. A GE LightSpeed RT 4-slice helical CT scanner with a 80 cm bore size was installed in the radiation oncology department of the Newcastle Mater Hospital. This replaced our only simulator, a conventional unit. Specific issues relating to the imaging performance, and virtual simulation process with the large-bore multislice scanner were studied to ensure an accurate radiotherapy process. The detector array fully samples a 50 cm diameter scan circle. The reconstructed diameter can be increased to 65 cm with partial sampling of the extra volume. The GE Advantage Sim (ASim) virtual simulation software was commissioned, with transfer of CT images and DICOM RT plans to the Pinnacle radiotherapy planning system (RTPS) for dose calculation. Some specific issues investigated were: 1) The image quality performance for image reconstruction with the 65 cm area compared to 50 cm was measured with a line-pair phantom. 2) The accuracy of CT numbers with lateral position was assessed with a commercial electron density phantom. 3) Couch lateral movement and sag during acquisition were measured with the couch weighted with 86 kg. 4) The accuracy of the transfer of plans from ASim to Pinnacle was verified with known plan geometries. Image resolution throughout the entire CT image was found to be significantly lower when scan reconstruction was performed with 65 cm scan circle compared to 50 cm. The 0.3, 0.38 and 0.5 1p/mm bars were clearly distinguishable with the 50 cm reconstruction compared to only the 0.3 1p/mm bars in the 65 cm reconstruction. 2) CT numbers varied significantly outside the 50 cm reconstructed area. 3) Couch lateral movement during scanning was within 1 mm. Couch sag was 4 mm at the imaging plane

Fatal invasive aspergillosis: a rare co-infection with an unexpected image presentation in a patient with dengue shock syndrome.

Science.gov (United States)

Wang, Hui-Ching; Chang, Ko; Lu, Po-Liang; Tsai, Kun-Bow; Chen, Huang-Chi

2017-03-01

Pulmonary infiltration and pleural effusion caused by permeability syndrome are the hallmark of pulmonary manifestation of dengue cases. We report a 95-year-old chronic obstructive pulmonary disease case having dengue shock syndrome. Chest X-ray examination revealed diffuse lung infiltration. However, bilateral pneumotoceles were unexpectedly found in computed tomography (CT) images. Dengue virus type 2 infection was confirmed by virus culture, serology and reverse transcriptase-polymerase chain reaction. Profound shock with bilateral lung infiltration developed rapidly in 2 days with supportive care and empirical ampicillin/ sulbactam. Bronchoscopy revealed a whitish plaque over bilateral upper bronchi. Biopsy via bronchoscopy revealed moulds with vascular invasion. Culture of bronchial alveolar lavage yielded Aspergillus flavus. The patient died despite amphotericin B treatment, which was started since finding the whitish plaque with bronchoscopy examination. Besides to considering capillary leakage syndrome, our case report and literature review alert clinicians that CT and bronchoscopy may help to identify the true pathogen though all cases with concurrent dengue and Aspergillus infections had fatal outcomes. © 2015 John Wiley & Sons Ltd.

CT findings of pulmonary aspergillosis

International Nuclear Information System (INIS)

Cheon, Jung Eun; Im, Jung Gi; Goo, Jin Mo; Kim, Hong Dae; Han, Man Chung

1995-01-01

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

Brachytherapy reconstruction using orthogonal scout views from the CT

International Nuclear Information System (INIS)

Perez, J.; Lliso, F.; Carmona, V.; Bea, J.; Tormo, A.; Petschen, I.

1996-01-01

Introduction: CT assisted brachytherapy planning is demonstrating to have great advantages as external RT planning does. One of the problems we have found in this approach with the conventional gynecological Fletcher applicators is the high amount of artefacts (ovoids with rectal and vessical protections) in the CT slice. We have introduced a reconstruction method based on scout views in order to avoid this problem, allowing us to perform brachytherapy reconstruction completely CT assisted. We use a virtual simulation chain by General Electric Medical Systems. Method and discussion: Two orthogonal scout views (0 and 90 tube positions) are performed. The reconstruction method takes into account the virtual position of the focus and the fact that there is only divergence in the transverse plane. Algorithms developed for sources as well as for reference points localisation (A, B, lymphatic Fletcher trapezoid, pelvic wall, etc.) are presented. This method has the following practical advantages: the porte-cassette is not necessary, the image quality can be improved (it is very helpful in pelvic lateral views that are critical in conventional radiographs), the total time to get the data is smaller than for conventional radiographs (reduction of patient motion effects) and problems that appear in CT-slice based reconstruction in the case of strongly curved intrauterine applicators are avoided. Even though the resolution is smaller than in conventional radiographs it is good enough for brachytherapy. Regarding the CT planning this method presents the interesting feature that the co-ordinate system is the same for the reconstruction process that for the CT-slices set. As the application can be reconstructed from scout views and the doses can be evaluated on CT slices it is easier to correlate the dose values obtained for the traditional points with those provided by the CT information

A prospective, randomized study addressing the need for physical simulation following virtual simulation

International Nuclear Information System (INIS)

Valicenti, Richard K.; Waterman, Frank M.; Corn, Benjamin W.; Curran, Walter J.

1997-01-01

Purpose: To accurately implement a treatment plan obtained by virtual or CT simulation, conventional or physical simulation is still widely used. To evaluate the need for physical simulation, we prospectively randomized patients to undergo physical simulation or no additional simulation after virtual simulation. Methods and Materials: From July 1995 to September 1996, 75 patients underwent conformal four-field radiation therapy planning for prostate cancer with a commercial grade CT simulator. The patients were randomized to undergo either port filming immediately following physical simulation or port filming alone. The precision of implementing the devised plan was evaluated by comparing simulator radiographs and/or port films against the digitally reconstructed radiographs (DRRs) for x, y, and z displacements of the isocenter. Changes in beam aperture were also prospectively evaluated. Results: Thirty-seven patients were randomized to undergo physical simulation and first day port filming, and 38 had first day treatment verification films only without a physical simulation. Seventy-eight simulator radiographs and 195 first day treatment port films were reviewed. There was no statistically significant reduction in treatment setup error (>5 mm) if patients underwent physical simulation following virtual simulation. No patient required a resimulation, and there was no significant difference in changes of beam aperture. Conclusions: Following virtual simulation, physical simulation may not be necessary to accurately implement the conformal four-field technique. Because port filming appears to be sufficient to assure precise and reliable execution of a devised treatment plan, physical simulation may be eliminated from the process of CT based planning when virtual simulation is available

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 VNC and TNC series were observed for liver, vena portae, kidneys, pancreas, muscle and bone marrow (Pearson's correlation coefficient ≥0.75). Mean image noise was significantly higher in TNC images (P VNC and TNC 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.

In-vitro study on the accuracy of a simple-design CT-guided stent for dental implants

International Nuclear Information System (INIS)

Huh, Young June; Choi, Bo Ram; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul

2012-01-01

An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement. A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated. The deviation of the entry point and angulation of the central axis in the reference plane were 0.47±0.27 mm, 0.57±0.23 mm, and 0.64±0.16 degree, 0.57±0.15 degree, respectively. However, for the two different angulations in each group, the 20 degree angulation showed a greater error in the deviation of the entry point than did the 10 degree angulation. The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.

Generalities of anomalous CT chest non tumoral

International Nuclear Information System (INIS)

Dibarboure, L.

2012-01-01

This presentation is about the generalities of multidetector CT in the pulmonary, the diaphragmatic, the pleural and the mediastinum pathology.These techniques as well as the virtual endoscopy allow visualize volumetric thorax reconstructions, brain diseases, opacities, radiolucent images, respiratory and vascular diseases, pneumonia, embolism, AIDS stage, tuberculosis, tumors, etc

T1-weighted MRI as a substitute to CT for refocusing planning in MR-guided focused ultrasound

International Nuclear Information System (INIS)

Wintermark, Max; Sumer, Suna; Lau, Benison; Cupino, Alan; Tustison, Nicholas J; Demartini, Nicholas; Elias, William J; Kassell, Neal; Patrie, James T; Xin, Wenjun; Eames, Matt; Snell, John; Hananel, Arik; Aubry, Jean-Francois

2014-01-01

Precise focusing is essential for transcranial MRI-guided focused ultrasound (TcMRgFUS) to minimize collateral damage to non-diseased tissues and to achieve temperatures capable of inducing coagulative necrosis at acceptable power deposition levels. CT is usually used for this refocusing but requires a separate study (CT) ahead of the TcMRgFUS procedure. The goal of this study was to determine whether MRI using an appropriate sequence would be a viable alternative to CT for planning ultrasound refocusing in TcMRgFUS. We tested three MRI pulse sequences (3D T1 weighted 3D volume interpolated breath hold examination (VIBE), proton density weighted 3D sampling perfection with applications optimized contrasts using different flip angle evolution and 3D true fast imaging with steady state precision T2-weighted imaging) on patients who have already had a CT scan performed. We made detailed measurements of the calvarial structure based on the MRI data and compared those so-called ‘virtual CT’ to detailed measurements of the calvarial structure based on the CT data, used as a reference standard. We then loaded both standard and virtual CT in a TcMRgFUS device and compared the calculated phase correction values, as well as the temperature elevation in a phantom. A series of Bland–Altman measurement agreement analyses showed T1 3D VIBE as the optimal MRI sequence, with respect to minimizing the measurement discrepancy between the MRI derived total skull thickness measurement and the CT derived total skull thickness measurement (mean measurement discrepancy: 0.025; 95% CL (−0.22–0.27); p = 0.825). The T1-weighted sequence was also optimal in estimating skull CT density and skull layer thickness. The mean difference between the phase shifts calculated with the standard CT and the virtual CT reconstructed from the T1 dataset was 0.08 ± 1.2 rad on patients and 0.1 ± 0.9 rad on phantom. Compared to the real CT, the MR-based correction showed a 1 °C drop on the

Uventet fund af endobronkial lungetumor ved bronkoskopi hos en storryger

DEFF Research Database (Denmark)

Gottlieb, Magnus; Clementsen, Paul Frost; Håkansson, Kåre

2014-01-01

A 60-year-old male heavy smoker surprisingly presented with a squamous cell carcinoma in the right upper lobe at bronchoscopy. Combined PET-CT classified the lung cancer as T1aN0M0. However, the endoscopic classification was T2a, which radically reversed the treatment schedule. Conclusions: 1......) A careful bronchoscopy is important even in cases where lung cancer is not expected. 2) Accurate endobronchial classification can be crucial. 3) There is need for training requirements to obtain a satisfactory level of competence in bronchoscopy....

Uventet fund af endobronkial lungetumor ved bronkoskopi hos en storryger

DEFF Research Database (Denmark)

Gottlieb, Magnus; Clementsen, Paul Frost; Håkansson, Kåre

2014-01-01

A 60-year-old male heavy smoker surprisingly presented with a squamous cell carcinoma in the right upper lobe at bronchoscopy. Combined PET-CT classified the lung cancer as T1aN0M0. However, the endoscopic classification was T2a, which radically reversed the treatment schedule. Conclusions: 1) A ......) A careful bronchoscopy is important even in cases where lung cancer is not expected. 2) Accurate endobronchial classification can be crucial. 3) There is need for training requirements to obtain a satisfactory level of competence in bronchoscopy....

Virtual unenhanced second generation dual-source CT of the liver: Is it time to discard the conventional unenhanced phase?

International Nuclear Information System (INIS)

Barrett, T.; Bowden, D.J.; Shaida, N.; Godfrey, E.M.; Taylor, A.; Lomas, D.J.; Shaw, A.S.

2012-01-01

Introduction: Dual-energy dual source CT can almost simultaneously image patients using two different tube potentials, allowing material decomposition and creation of ‘virtual unenhanced’ (VU) images from post-contrast series. Methods: 75 patients undergoing triple-phase liver CT examinations were imaged using a second generation dual-source CT machine with tube potentials 140/100 kVp. Post-processing VU series were derived from arterial and portal phases. Regions-of-interest from liver parenchyma and within fat (‘noise’ assessment) were drawn to compare VU series to conventional unenhanced (CU) series. Subjective analysis assessed image quality and the suitability of VU to replace CU series. Results: Mean Hounsfield unit (HU) values of liver were higher in the VU series: portal 51.9 (SD = 10.29), arterial 51.1 (SD = 10.05), compared to the CU series 49.2 (SD = 9.11); P < 0.001. However, Pearson's correlation of the VU and CU series remained excellent: 0.838 (portal), 0.831 (arterial). Bland–Altman plots also showed good agreement between both VU and the CU datasets. Noise measurements were significantly lower in both VU series (P < 0.001). For subjective analysis, image quality was rated as very good/excellent in 100% of CU images, 93.3% of portal VU and 88.7% of arterial VU series. Overall, portal VU and arterial VU images were acceptable replacements for the CU series in 97.4% and 96.1%, respectively. Post-processing was noted to create a number of artefacts in VU images – knowledge of these is essential for interpretation. Conclusions: Portal and arterial-derived VU images objectively correlate to CU images and demonstrate good image quality and acceptability. VU image sets could replace the conventional unenhanced images in the vast majority of cases, significantly reducing radiation dose.

Comparison of classic simulation and virtual simulation in breast irradiation: prospective study on 14 patients

International Nuclear Information System (INIS)

Bauduceau, O.; Pons, P.; Romero, L.; Fayolle, M.; Campana, F.; Bollet, M.

2005-01-01

Purpose. - To compare conventional 2D simulation and virtual simulation on 14 patients with breast cancer. Patients and methods. - Patients were simulated for treatment using standard procedure. They subsequently underwent CT scan in the treatment position. The CTV was defined as breast tissue. The PTV was obtained by adding a 3D margin of 1 cm around CTV. Organs at risk (lungs and heart) were outlined. Ballistics and dose distribution obtained with the two planning methods were compared. Results. - With conventional simulation, 95% of CTV received 95% of the dose prescribed. Virtual simulation significantly improved dosimetric coverage of PTV without increasing irradiation volume of lung and heart. In 2D simulation, using three slices allowed optimisation by adjusting wedge angle. The five-slice plan was a much better predictor of the maximum dose regions when compared to the three-slice plan. Using entire CT data did not give any benefit. Conclusion. - Variations in CTV delineation and PTV definition limit interest of virtual simulation. In classic simulation, a 5 CT slice-plan can be used to optimise dose distribution. (author)

双源 CT 双能量虚拟平扫在胸部疾病的临床应用研究%Clinical application of dual-energy virtual non-contrast of dual source CT for thoracic diseases

Institute of Scientific and Technical Information of China (English)

刘江勇; 王荣品; 王骋; 刘新峰; 骆科进

2017-01-01

Objective To investigate the applicational value of dual-energy virtual non-contrast (VNC)of dual source computed tomography (DSCT)for the thoracic diseases.Methods 60 patients with thoracic diseases were performed with conventional plain scan and dual energy enhanced scan.The image qualities of conventional plain scan and VNC of the patients were retrospectively evaluated.The mean CT values and the signal to noise ratio(SNR)of descending aorta,left atrium and muscles adjacent the thoracic vertebral spine were measured.The image quality and the radiation dosage were compared between conventional plain scan and virtual dual-energy scan.Results Of the 60 cases of patients,the mean CT values of descending aorta between conventional plain scan and VNC scan was statistically significant (P 0.05).VNC scan were higher than conventional plain scan in SNR of the descending aorta,left atrium and muscles (P 0.05).For the image quality of thoracic lesions,the features of VNC scan were very close to those of conventional plain scan except 4 (4/49)cases of VNC images with blurrier borders.No significant difference was found in the average scores of image quality between the conventional plain scan and VNC scan.The radiation doses of dual-energy virtual non-contrast were slightly higher than conventional plain scan in the values of computed tomography dose index volume (CTDIvol),dose-length product (DLP)and effective dose (ED)(P 0.05)。VNC 降主动脉、左心房及胸椎椎体后方肌肉的 SNR 均高于常规平扫(P 0.05)。VNC 图像仅对4(4/49)例肺门区微小钙化灶显示较常规平扫图像模糊。常规平扫与 VNC 图像的质量评分差异无统计学意义。VNC 的容积 CT 剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效剂量(ED)均稍高于常规平扫(P <0.05)，但节省1次常规平扫剂量，平均每人可减少2.22 mSv ED。结论DSCT双能量 VNC 技术应用于胸部扫描，其图像质量能达到诊断要求，可有效降低辐射剂量，具有较好的临床应用价值。

Implementation of a virtual laryngoscope system using efficient reconstruction algorithms.

Science.gov (United States)

Luo, Shouhua; Yan, Yuling

2009-08-01

Conventional fiberoptic laryngoscope may cause discomfort to the patient and in some cases it can lead to side effects that include perforation, infection and hemorrhage. Virtual laryngoscopy (VL) can overcome this problem and further it may lower the risk of operation failures. Very few virtual endoscope (VE) based investigations of the larynx have been described in the literature. CT data sets from a healthy subject were used for the VL studies. An algorithm of preprocessing and region-growing for 3-D image segmentation is developed. An octree based approach is applied in our VL system which facilitates a rapid construction of iso-surfaces. Some locating techniques are used for fast rendering and navigation (fly-through). Our VL visualization system provides for real time and efficient 'fly-through' navigation. The virtual camera can be arranged so that it moves along the airway in either direction. Snap shots were taken during fly-throughs. The system can automatically adjust the direction of the virtual camera and prevent collisions of the camera and the wall of the airway. A virtual laryngoscope (VL) system using OpenGL (Open Graphics Library) platform for interactive rendering and 3D visualization of the laryngeal framework and upper airway is established. OpenGL is supported on major operating systems and works with every major windowing system. The VL system runs on regular PC workstations and was successfully tested and evaluated using CT data from a normal subject.

Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

Energy Technology Data Exchange (ETDEWEB)

Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi [Hiroshima Univ. (Japan). Hospital] (and others)

2002-12-01

In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

International Nuclear Information System (INIS)

Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi

2002-01-01

In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

[Electrocautery and bronchoscopy as a first step for the management of central airway obstruction and associated hemoptysis].

Science.gov (United States)

Jalilie, Alfredo; Carvajal, Juan Carlos; Aparicio, Rodrigo; Meneses, Manuel

2016-11-01

Central airway obstruction caused by malignant or benign lesions, associated in some cases with hemoptysis, is a condition with high morbidity and mortality. The use of electrocautery by flexible bronchoscopy is an initial treatment option with immediate improvement of obstruction symptoms. It is as effective as Nd: YAG laser. To describe the usefulness of electrocautery in the management of central obstruction of the airway and hemoptysis. A retrospective, descriptive study of patients referred for management of central airway obstruction or associated hemoptysis. Diagnoses, symptoms (dyspnea, cough, and hemoptysis) and radiology before and after the procedures were analyzed. Eighteen patients aged 59 ± 12 years (66% males) were evaluated, registering 25 endoscopic procedures. Three conditions were found: partial or complete airway obstruction, hemoptysis and post lung transplant bronchial stenosis. Seventy two percent presented with dyspnea, 61% with cough and 33% with hemoptysis. Sixty six percent of patients had airway obstruction caused by malignant metastatic lesions. After electrocautery, 17 patients (94.4%) improved their symptoms and achieved complete airway clearing. Three patients had significant bronchial stenosis after lung transplant achieving subsequent clearing after electrocautery. Electrocautery during flexible bronchoscopy is an effective and safe procedure for the management of central airway obstruction and associated hemoptysis.

Optical coherence tomography in conjunction with bronchoscopy

International Nuclear Information System (INIS)

Rodrigues, Ascedio Jose; Takimura, Celso Kiyochi; Lemos Neto, Pedro Alves; Figueiredo, Viviane Rossi

2012-01-01

To evaluate the feasibility of and the potential for using optical coherence tomography in conjunction with conventional bronchoscopy in the evaluation of the airways. Methods: This was a pilot study based on an ex vivo experimental model involving three animals: one adult New Zealand rabbit and two Landrace pigs. An optical coherence tomography imaging catheter was inserted through the working channel of a flexible bronchoscope in order to reach the distal trachea of the animals. Images of the walls of the trachea were systematically taken along its entire length, from the distal to the proximal portion. Results: The imaging catheter was easily adapted to the working channel of the bronchoscope. High-resolution images of cross sections of the trachea were taken in real time, precisely delineating microstructures, such as the epithelium, submucosa, and cartilage, as well as the adventitia of the anterior and lateral tracheal walls. The corresponding layers of the epithelium, mucosa, and cartilage were clearly differentiated. The mucosa, submucosa, and trachealis muscle were clearly identified in the posterior wall. Conclusions: It is feasible to use an optical coherence tomography imaging catheter in combination with a flexible bronchoscope. Optical coherence tomography produces high resolution images that reveal the microanatomy of the trachea, including structures that are typically seen only on images produced by conventional histology. (author)

Optical coherence tomography in conjunction with bronchoscopy

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Ascedio Jose; Takimura, Celso Kiyochi; Lemos Neto, Pedro Alves; Figueiredo, Viviane Rossi, E-mail: ascedio@gmail.com [Servico de Endoscopia Respiratoria, Hospital das Clinicas, Universidade de Sao Paulo (FM/USP), SP (Brazil)

2012-07-01

To evaluate the feasibility of and the potential for using optical coherence tomography in conjunction with conventional bronchoscopy in the evaluation of the airways. Methods: This was a pilot study based on an ex vivo experimental model involving three animals: one adult New Zealand rabbit and two Landrace pigs. An optical coherence tomography imaging catheter was inserted through the working channel of a flexible bronchoscope in order to reach the distal trachea of the animals. Images of the walls of the trachea were systematically taken along its entire length, from the distal to the proximal portion. Results: The imaging catheter was easily adapted to the working channel of the bronchoscope. High-resolution images of cross sections of the trachea were taken in real time, precisely delineating microstructures, such as the epithelium, submucosa, and cartilage, as well as the adventitia of the anterior and lateral tracheal walls. The corresponding layers of the epithelium, mucosa, and cartilage were clearly differentiated. The mucosa, submucosa, and trachealis muscle were clearly identified in the posterior wall. Conclusions: It is feasible to use an optical coherence tomography imaging catheter in combination with a flexible bronchoscope. Optical coherence tomography produces high resolution images that reveal the microanatomy of the trachea, including structures that are typically seen only on images produced by conventional histology. (author)

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.

Science.gov (United States)

Bongers, Malte N; Schabel, Christoph; Krauss, Bernhard; Tsiflikas, Ilias; Ketelsen, Dominik; Mangold, Stefanie; Claussen, Claus D; Nikolaou, Konstantin; Thomas, Christoph

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 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. • Poor contrast makes it difficult to detect thrombosis in CT. • Dual-energy-CT allows contrast optimization using monoenergetic extrapolations (MEI) and iodine maps (IM). • Noise-optimized-MEI and IM are significantly superior to single-energy-CT in delineation of thrombosis. • Noise-optimized-MEI and IM may facilitate the detection of deep vein thrombosis.

Quantification of coronary artery calcium on the basis of dual-energy coronary CT angiography.

Science.gov (United States)

Schwarz, Florian; Nance, John W; Ruzsics, Balazs; Bastarrika, Gorka; Sterzik, Alexander; Schoepf, U Joseph

2012-09-01

To evaluate the feasibility of using virtual noncontrast material-enhanced (VNC) computed tomographic (CT) series derived from dual-energy CT imaging studies for coronary artery calcium quantification. This HIPAA-compliant study was institutional review board approved; all patients provided written informed consent. Thirty-six patients prospectively underwent noncontrast-enhanced CT calcium scoring followed by coronary CT angiography performed in dual-energy mode. By using different reconstruction algorithms, three VNC series were generated and evaluated for noise and efficiency of virtual iodine removal. Two readers independently quantified calcium on VNC images and true noncontrast-enhanced conventional calcium scoring series. A leave-one-out cross validation was used to assess the accuracy of calcium score prediction from VNC series by means of linear regression. CT value histograms of the VNC series closely resembled the profile in the true noncontrast-enhanced series. There was excellent correlation between calcium volumes on the VNC series and true noncontrast-enhanced series on a per-patient (r = 0.94, P VNC series was excellent (r = 0.82). Multiethnic Study of Atherosclerosis rankings that were derived from the predicted calcium scores also showed excellent agreement (intraclass correlation coefficient = 0.909). Coronary artery calcium identification and quantification based on dual-energy coronary CT angiographic studies may obviate the need for dedicated CT calcium scoring studies. © RSNA, 2012

Is there a superior simulator for human anatomy education? How virtual dissection can overcome the anatomic and pedagogic limitations of cadaveric dissection.

Science.gov (United States)

Darras, Kathryn E; de Bruin, Anique B H; Nicolaou, Savvas; Dahlström, Nils; Persson, Anders; van Merriënboer, Jeroen; Forster, Bruce B

2018-03-23

Educators must select the best tools to teach anatomy to future physicians and traditionally, cadavers have always been considered the "gold standard" simulator for living anatomy. However, new advances in technology and radiology have created new teaching tools, such as virtual dissection, which provide students with new learning opportunities. Virtual dissection is a novel way of studying human anatomy through patient computed tomography (CT) scans. Through touchscreen technology, students can work together in groups to "virtually dissect" the CT scans to better understand complex anatomic relationships. This article presents the anatomic and pedagogic limitations of cadaveric dissection and explains what virtual dissection is and how this new technology may be used to overcome these limitations.

Reprojection method using CT data. New means of visualization by improved technique

International Nuclear Information System (INIS)

Ishimori, Yoshiyuki; Tanaka, Masato; Komuro, Hiroyuki

1995-01-01

Reprojection Method (RPM) using computed tomography (CT) data can create simulating images of plain X-ray film. We could create material extracted images by selecting projected CT values, and created tomographic images by selecting spatial values. Virtual X-ray source can be set anywhere. So it can create stereographic images composed of a pair of beam's eye view, and can create panoramic images to set the source inside the volume data. Since RPM does not need the binaryzation process, the densities of the image reflect the original CT value of each voxel. RPM using CT data is a useful method to get the most information regarding X-ray attenuation and to cope with the fast scan CT system. (author)

(18)F-FDG PET-CT simulation for non-small-cell lung cancer: effect in patients already staged by PET-CT.

Science.gov (United States)

Hanna, Gerard G; McAleese, Jonathan; Carson, Kathryn J; Stewart, David P; Cosgrove, Vivian P; Eakin, Ruth L; Zatari, Ashraf; Lynch, Tom; Jarritt, Peter H; Young, V A Linda; O'Sullivan, Joe M; Hounsell, Alan R

2010-05-01

Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition. A total of 28 patients with Stage IA-IIIB NSCLC were enrolled. All patients had undergone staging PET-CT to ensure suitability for radical RT. Of the 28 patients, 14 received induction chemotherapy. In place of a RT planning CT scan, patients underwent scanning on a PET-CT scanner. In a virtual planning study, four oncologists independently delineated the GTV on the CT scan alone and then on the PET-CT scan. Intraobserver and interobserver variability were assessed using the concordance index (CI), and the results were compared using the Wilcoxon signed ranks test. PET-CT improved the CI between observers when defining the GTV using the PET-CT images compared with using CT alone for matched cases (median CI, 0.57 for CT and 0.64 for PET-CT, p = .032). The median of the mean percentage of volume change from GTV(CT) to GTV(FUSED) was -5.21% for the induction chemotherapy group and 18.88% for the RT-alone group. Using the Mann-Whitney U test, this was significantly different (p = .001). PET-CT RT planning scan, in addition to a staging PET-CT scan, reduces interobserver variability in GTV definition for NSCLC. The GTV size with PET-CT compared with CT in the RT-alone group increased and was reduced in the induction chemotherapy group.

18F-FDG PET-CT Simulation for Non-Small-Cell Lung Cancer: Effect in Patients Already Staged by PET-CT

International Nuclear Information System (INIS)

Hanna, Gerard G.; McAleese, Jonathan; Carson, Kathryn J.; Stewart, David P.; Cosgrove, Vivian P.; Eakin, Ruth L.; Zatari, Ashraf; Lynch, Tom; Jarritt, Peter H.; Young, V.A. Linda D.C.R.; O'Sullivan, Joe M.

2010-01-01

Purpose: Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition. Methods and Materials: A total of 28 patients with Stage IA-IIIB NSCLC were enrolled. All patients had undergone staging PET-CT to ensure suitability for radical RT. Of the 28 patients, 14 received induction chemotherapy. In place of a RT planning CT scan, patients underwent scanning on a PET-CT scanner. In a virtual planning study, four oncologists independently delineated the GTV on the CT scan alone and then on the PET-CT scan. Intraobserver and interobserver variability were assessed using the concordance index (CI), and the results were compared using the Wilcoxon signed ranks test. Results: PET-CT improved the CI between observers when defining the GTV using the PET-CT images compared with using CT alone for matched cases (median CI, 0.57 for CT and 0.64 for PET-CT, p = .032). The median of the mean percentage of volume change from GTV CT to GTV FUSED was -5.21% for the induction chemotherapy group and 18.88% for the RT-alone group. Using the Mann-Whitney U test, this was significantly different (p = .001). Conclusion: PET-CT RT planning scan, in addition to a staging PET-CT scan, reduces interobserver variability in GTV definition for NSCLC. The GTV size with PET-CT compared with CT in the RT-alone group increased and was reduced in the induction chemotherapy group.

Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results

International Nuclear Information System (INIS)

Bielen, Didier; Thomeer, Maarten; Vanbeckevoort, Dirk; Marchal, Guy; Kiss, Gabriel; Maes, Frederik; Rutgeerts, Paul

2003-01-01

The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC (n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup. (orig.)

Development of a Radiation Dose Reporting Software for X-ray Computed Tomography (CT)

Science.gov (United States)

Ding, Aiping

X-ray computed tomography (CT) has experienced tremendous technological advances in recent years and has established itself as one of the most popular diagnostic imaging tools. While CT imaging clearly plays an invaluable role in modern medicine, its rapid adoption has resulted in a dramatic increase in the average medical radiation exposure to the worldwide and United States populations. Existing software tools for CT dose estimation and reporting are mostly based on patient phantoms that contain overly simplified anatomies insufficient in meeting the current and future needs. This dissertation describes the development of an easy-to-use software platform, “VirtualDose”, as a service to estimate and report the organ dose and effective dose values for patients undergoing the CT examinations. “VirtualDose” incorporates advanced models for the adult male and female, pregnant women, and children. To cover a large portion of the ignored obese patients that frequents the radiology clinics, a new set of obese male and female phantoms are also developed and applied to study the effects of the fat tissues on the CT radiation dose. Multi-detector CT scanners (MDCT) and clinical protocols, as well as the most recent effective dose algorithms from the International Commission on Radiological Protection (ICRP) Publication 103 are adopted in “VirtualDose” to keep pace with the MDCT development and regulatory requirements. A new MDCT scanner model with both body and head bowtie filter is developed to cover both the head and body scanning modes. This model was validated through the clinical measurements. A comprehensive slice-by-slice database is established by deriving the data from a larger number of single axial scans simulated on the patient phantoms using different CT bowtie filters, beam thicknesses, and different tube voltages in the Monte Carlo N-Particle Extended (MCNPX) code. When compared to the existing CT dose software packages, organ dose data in this

CT digital radiography: Alternative technique for airway evaluation in physically disabled patients

International Nuclear Information System (INIS)

Mandell, G.A.; Harcke, H.T.; Brunson, G.; Delengowski, R.; Padman, R.

1987-01-01

Evaluation of the airway for the presence of granulation tissue prior to removal of a tracheostomy is essential to prevent sudden respiratory decompensation secondary to obstruction. Airway examination in a brain and/or spinal cord injured patient is especially difficult under fluoroscopy. The patient's lack of mobility results in poor visualization of the trachea, secondary to the overlying dense osseous components of the shoulders and thoracic cage. A CT localization view (digital view), which allows manipulation and magnification of the digital data in order to see the hidden airway and detect associated obstructing lesions, is proffered as an alternative technique to high KV, magnification technique. Thirteen examinations were performed satisfactorily in eleven patients examined by this technique with little expenditure of time, physical exertion, and irradiation. The sensitivity, specificity and accuracy of digital airway examination were 100%, 67% and 92% respectively with bronchoscopy used as the standard. (orig.)

Minimally invasive, imaging guided virtual autopsy compared to conventional autopsy in foetal, newborn and infant cases: study protocol for the paediatric virtual autopsy trial

Science.gov (United States)

2014-01-01

Background In light of declining autopsy rates around the world, post-mortem MR imaging is a promising alternative to conventional autopsy in the investigation of infant death. A major drawback of this non-invasive autopsy approach is the fact that histopathological and microbiological examination of the tissue is not possible. The objective of this prospective study is to compare the performance of minimally invasive, virtual autopsy, including CT-guided biopsy, with conventional autopsy procedures in a paediatric population. Methods/Design Foetuses, newborns and infants that are referred for autopsy at three different institutions associated with the University of Zurich will be eligible for recruitment. All bodies will be examined with a commercial CT and a 3 Tesla MRI scanner, masked to the results of conventional autopsy. After cross-sectional imaging, CT-guided tissue sampling will be performed by a multifunctional robotic system (Virtobot) allowing for automated post-mortem biopsies. Virtual autopsy results will be classified with regards to the likely final diagnosis and major pathological findings and compared to the results of conventional autopsy, which remains the diagnostic gold standard. Discussion There is an urgent need for the development of alternative post-mortem examination methods, not only as a counselling tool for families and as a quality control measure for clinical diagnosis and treatment but also as an instrument to advance medical knowledge and clinical practice. This interdisciplinary study will determine whether virtual autopsy will narrow the gap in information between non-invasive and traditional autopsy procedures. Trial Registration ClinicalTrials.gov: NCT01888380 PMID:24438163

Pneumoperitoneum after virtual colonoscopy: causes, risk factors, and management.

Science.gov (United States)

Baccaro, Leopoldo M; Markelov, Alexey; Wilhelm, Jakub; Bloch, Robert

2014-06-01

Computed tomographic virtual colonoscopy (CTVC) is a safe and minimally invasive modality when compared with fiberoptic colonoscopy for evaluating the colon and rectum. We have reviewed the risks for colonic perforation by investigating the relevant literature. The objectives of this study were to assess the risk of colonic perforation during CTVC, describe risk factors, evaluate ways to reduce the incidence complications, and to review management and treatment options. A formal search of indexed publications was performed through PubMed. Search queries using keywords "CT colonography," "CT virtual colonoscopy," "virtual colonoscopy," and "perforation" yielded a total of 133 articles. A total of eight case reports and four review articles were selected. Combining case reports and review articles, a total of 25 cases of colonic perforation after CTVC have been reported. Causes include, but are not limited to, diverticular disease, irritable bowel diseases, obstructive processes, malignancies, and iatrogenic injury. Both operative and nonoperative management has been described. Nonoperative management has been proven safe and successful in minimally symptomatic and stable patients. Colonic perforation after CTVC is a rare complication and very few cases have been reported. Several risk factors are recurrent in the literature and must be acknowledged at the time of the study. Management options vary and should be tailored to each individual patient.

Exploring metal artifact reduction using dual-energy CT with pre-metal and post-metal implant cadaver comparison: are implant specific protocols needed?

Science.gov (United States)

Wellenberg, Ruud H H; Donders, Johanna C E; Kloen, Peter; Beenen, Ludo F M; Kleipool, Roeland P; Maas, Mario; Streekstra, Geert J

2017-08-25

To quantify and optimize metal artifact reduction using virtual monochromatic dual-energy CT for different metal implants compared to non-metal reference scans. Dual-energy CT scans of a pair of human cadaver limbs were acquired before and after implanting a titanium tibia plate, a stainless-steel tibia plate and a titanium intramedullary nail respectively. Virtual monochromatic images were analyzed from 70 to 190 keV. Region-of-interest (ROI), used to determine fluctuations and inaccuracies in CT numbers of soft tissues and bone, were placed in muscle, fat, cortical bone and intramedullary tibia canal. The stainless-steel implant resulted in more pronounced metal artifacts compared to both titanium implants. CT number inaccuracies in 70 keV reference images were minimized at 130, 180 and 190 keV for the titanium tibia plate, stainless-steel tibia plate and titanium intramedullary nail respectively. Noise, measured as the standard deviation of pixels within a ROI, was minimized at 130, 150 and 140 keV for the titanium tibia plate, stainless-steel tibia plate and titanium intramedullary nail respectively. Tailoring dual-energy CT protocols using implant specific virtual monochromatic images minimizes fluctuations and inaccuracies in CT numbers in bone and soft tissues compared to non-metal reference scans.

The impact of virtual simulation in palliative radiotherapy for non-small-cell lung cancer

International Nuclear Information System (INIS)

McJury, Mark; Fisher, Patricia M.; Pledge, Simon; Brown, Gillian; Anthony, Catherine; Hatton, Matthew Q.; Conway, John; Robinson, Martin H.

2001-01-01

Background and purpose: Radiotherapy is widely used to palliate local symptoms in non-small-cell lung cancer. Using conventional X-ray simulation, it is often difficult to accurately localize the extent of the tumour. We report a randomized, double blind trial comparing target localization with conventional and virtual simulation. Methods: Eighty-six patients underwent both conventional and virtual simulation. The conventional simulator films were compared with digitally reconstructed radiographs (DRRs) produced from the computed tomography (CT) data. The treatment fields defined by the clinicians using each modality were compared in terms of field area, position and the implications for target coverage. Results: Comparing fields defined by each study arm, there was a major mis-match in coverage between fields in 66.2% of cases, and a complete match in only 5.2% of cases. In 82.4% of cases, conventional simulator fields were larger (mean 24.5±5.1% (95% confidence interval)) than CT-localized fields, potentially contributing to a mean target under-coverage of 16.4±3.5% and normal tissue over-coverage of 25.4±4.2%. Conclusions: CT localization and virtual simulation allow more accurate definition of the target volume. This could enable a reduction in geographical misses, while also reducing treatment-related toxicity

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

Science.gov (United States)

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

2013-11-01

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. The creation of virtual teeth begins by scanning a tooth with a cone beam CT. The resulting scan consists of multiple two-dimensional grey-scale images. The specially designed software program ColorMapEditor connects these two-dimensional images to create a three-dimensional tooth. With this software, any aspect of the tooth can be modified, including its colour, volume, shape and density, resulting in the creation of virtual teeth of any type. This article provides examples of realistic virtual teeth with and without pathology that can be used for dental education. ColorMapEditor offers infinite possibilities to adjust and add options for the optimisation of virtual teeth. Virtual teeth have unlimited availability for dental students, allowing them to practise as often as required. Virtual teeth can be made and adjusted to any shape with any type of pathology. Further developments in software and hardware technology are necessary to refine the ability to colour and shape the interior of the pulp chamber and surface of the tooth to enable not only treatment but also diagnostics and thus create a greater degree of realism. The creation and use of virtual teeth in dental education appears to be feasible but is still in development; it offers many opportunities for the creation of teeth with various pathologies, although an evaluation of its use in dental education is still required. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Advanced virtual monochromatic reconstruction of dual-energy unenhanced brain computed tomography in children: comparison of image quality against standard mono-energetic images and conventional polychromatic computed tomography

Energy Technology Data Exchange (ETDEWEB)

Park, Juil [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); Choi, Young Hun [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Cheon, Jung-Eun; Kim, Woo Sun; Kim, In-One [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); 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); Pak, Seong Yong [Siemens Healthineers, Seoul (Korea, Republic of); Krauss, Bernhard [Siemens Healthineers, Forchheim (Germany)

2017-11-15

Advanced virtual monochromatic reconstruction from dual-energy brain CT has not been evaluated in children. To determine the most effective advanced virtual monochromatic imaging energy level for maximizing pediatric brain parenchymal image quality in dual-energy unenhanced brain CT and to compare this technique with conventional monochromatic reconstruction and polychromatic scanning. Using both conventional (Mono) and advanced monochromatic reconstruction (Mono+) techniques, we retrospectively reconstructed 13 virtual monochromatic imaging energy levels from 40 keV to 100 keV in 5-keV increments from dual-source, dual-energy unenhanced brain CT scans obtained in 23 children. We analyzed gray and white matter noise ratios, signal-to-noise ratios and contrast-to-noise ratio, and posterior fossa artifact. We chose the optimal mono-energetic levels and compared them with conventional CT. For Mono+maximum optima were observed at 60 keV, and minimum posterior fossa artifact at 70 keV. For Mono, optima were at 65-70 keV, with minimum posterior fossa artifact at 75 keV. Mono+ was superior to Mono and to polychromatic CT for image-quality measures. Subjective analysis rated Mono+superior to other image sets. Optimal virtual monochromatic imaging using Mono+ algorithm demonstrated better image quality for gray-white matter differentiation and reduction of the artifact in the posterior fossa. (orig.)

CT simulation technique for craniospinal irradiation in supine position

International Nuclear Information System (INIS)

Lee, Suk; Kim, Yong Bae; Chu, Sung Sil; Suh, Chang Ok; Kwon, Soo Il

2002-01-01

In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetric image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was performed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. CSI in the supine position was successfully performed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The difference between the DRRs and the portal films were less than 3 mm in the vertebral contour. CSI in the supine position is feasible in patients who cannot lie on

CT simulation technique for craniospinal irradiation in supine position

Energy Technology Data Exchange (ETDEWEB)

Lee, Suk; Kim, Yong Bae; Chu, Sung Sil; Suh, Chang Ok [Yonsei Cancer Center, College of Medicine, Yonsei University, Seoul (Korea, Republic of); Kwon, Soo Il [Kyonggi University, Seoul (Korea, Republic of)

2002-06-15

In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetric image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was performed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. CSI in the supine position was successfully performed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The difference between the DRRs and the portal films were less than 3 mm in the vertebral contour. CSI in the supine position is feasible in patients who cannot

Virtual reality in the operating room of the future.

Science.gov (United States)

Müller, W; Grosskopf, S; Hildebrand, A; Malkewitz, R; Ziegler, R

1997-01-01

In cooperation with the Max-Delbrück-Centrum/Robert-Rössle-Klinik (MDC/RRK) in Berlin, the Fraunhofer Institute for Computer Graphics is currently designing and developing a scenario for the operating room of the future. The goal of this project is to integrate new analysis, visualization and interaction tools in order to optimize and refine tumor diagnostics and therapy in combination with laser technology and remote stereoscopic video transfer. Hence, a human 3-D reference model is reconstructed using CT, MR, and anatomical cryosection images from the National Library of Medicine's Visible Human Project. Applying segmentation algorithms and surface-polygonization methods a 3-D representation is obtained. In addition, a "fly-through" the virtual patient is realized using 3-D input devices (data glove, tracking system, 6-DOF mouse). In this way, the surgeon can experience really new perspectives of the human anatomy. Moreover, using a virtual cutting plane any cut of the CT volume can be interactively placed and visualized in realtime. In conclusion, this project delivers visions for the application of effective visualization and VR systems. Commonly known as Virtual Prototyping and applied by the automotive industry long ago, this project shows, that the use of VR techniques can also prototype an operating room. After evaluating design and functionality of the virtual operating room, MDC plans to build real ORs in the near future. The use of VR techniques provides a more natural interface for the surgeon in the OR (e.g., controlling interactions by voice input). Besides preoperative planning future work will focus on supporting the surgeon in performing surgical interventions. An optimal synthesis of real and synthetic data, and the inclusion of visual, aural, and tactile senses in virtual environments can meet these requirements. This Augmented Reality could represent the environment for the surgeons of tomorrow.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Routine examination for tuberculosis is still indicated during bronchoscopy for pulmonary infiltrates

DEFF Research Database (Denmark)

Laub, Rasmus Rude; Sivapalan, Pradeesh; Wilcke, Torgny

2015-01-01

INTRODUCTION: Tuberculosis (TB) can present in numerous ways and can be radiological indistinguishable from cancer. In several guidelines for bronchoscopy (FOB) in low-incidence areas, a Mycobacterium tuberculosis test is only recommended when TB is clinically suspected. Due to the expenses...... associated with M. tuberculosis cultures, we did an analysis of tests obtained by FOB and other invasive procedures (endoscopic ultrasound (EUS)-guided needle biopsy via the oesophagus or trachea and percutaneous needle lung biopsy (PNLB)). METHODS: All patients tested positive for M. tuberculosis by culture...... and with samples obtained by FOB, EUS or PNLB in the 2008-2012 period were identified retrospectively in two centres in a low-incidence area (Copenhagen, Denmark). Patient records and radiological reports were reviewed. RESULTS: A total of 57 (1.2%) patients out of the 4,680 tested were M. tuberculosis culture...

Importance of Preoperative Rectal Ultrasound and CT in Rectal Tumors

International Nuclear Information System (INIS)

Schnellyova, T.

2011-01-01

Introduction: The reason of high mortality of colorectal carcinoma is above all the fact, that majority of diseases are detected in progressive stage. Radical change in this unfavorable mortality rate can be achieved only by targeted search for early stages of the disease. Early diagnostics consists in rectoscopy and colonoscopy. Regarding X-ray methods it is X-ray irigography. Regarding CT examinations it is CT irigography, virtual colonoscopy. Another examination can be USG examination of abdomen and endo sonographic examination of rectum. Materials and methods: In the period from June 2006 to December 2010, in 60 patients out of the total number 106 examined patients, tumorous affection of rectum CT examination of pelvis and abdomen separately or pelvisand abdomen at one session was made in 3186 patients. In 115 patients we discovered malign tumorous illness of colon. Metastatic affection in the form of distant metastases was proven n 63 patients. 403 patients had CT irigography examination. In 77 out of them we diagnosed colon carcinoma. CT colonoscopy did not discover in our group of 30 patients examined the presence of colon carcinoma. Results: In the group of 60 patients who were diagnosed rectal carcinoma, in 29 patients expansive infiltrative affection was evaluated in endorectal sonography, histologically confirmed in 28 patients - 96,5 %, expansive affection in 41 patients with histological verification in 100 %. With CT we diagnosed 52 expansive tumorous processes, histologically confirmed in 47 patients - 90,38 %. In 63 patients expansive infiltrative process was evaluated, histologically confirmed in 52 patients 82,53 %. In total of 115 examinations there was conformance with histological examination in 99 patients - 86,08 %. In CT irigography we diagnosed colon tumour in 77 patients. Expansive growth was evaluated in 40 patients, histologically confirmed in 37 patients - 92,5 %. Expansive infiltrative expansion was evaluated in 37 patients, with

Inter-algorithm lesion volumetry comparison of real and 3D simulated lung lesions in CT

Science.gov (United States)

Robins, Marthony; Solomon, Justin; Hoye, Jocelyn; Smith, Taylor; Ebner, Lukas; Samei, Ehsan

2017-03-01

The purpose of this study was to establish volumetric exchangeability between real and computational lung lesions in CT. We compared the overall relative volume estimation performance of segmentation tools when used to measure real lesions in actual patient CT images and computational lesions virtually inserted into the same patient images (i.e., hybrid datasets). Pathologically confirmed malignancies from 30 thoracic patient cases from Reference Image Database to Evaluate Therapy Response (RIDER) were modeled and used as the basis for the comparison. Lesions included isolated nodules as well as those attached to the pleura or other lung structures. Patient images were acquired using a 16 detector row or 64 detector row CT scanner (Lightspeed 16 or VCT; GE Healthcare). Scans were acquired using standard chest protocols during a single breath-hold. Virtual 3D lesion models based on real lesions were developed in Duke Lesion Tool (Duke University), and inserted using a validated image-domain insertion program. Nodule volumes were estimated using multiple commercial segmentation tools (iNtuition, TeraRecon, Inc., Syngo.via, Siemens Healthcare, and IntelliSpace, Philips Healthcare). Consensus based volume comparison showed consistent trends in volume measurement between real and virtual lesions across all software. The average percent bias (+/- standard error) shows -9.2+/-3.2% for real lesions versus -6.7+/-1.2% for virtual lesions with tool A, 3.9+/-2.5% and 5.0+/-0.9% for tool B, and 5.3+/-2.3% and 1.8+/-0.8% for tool C, respectively. Virtual lesion volumes were statistically similar to those of real lesions (.05 in most cases. Results suggest that hybrid datasets had similar inter-algorithm variability compared to real datasets.

Sixteen-slice multidetector computed tomographic virtual cystoscopy in the evaluation of a patient with suspected bladder tumor and history of bladder carcinoma operation.

Science.gov (United States)

Basak, Muzaffer; Ozkurt, Huseyin; Tanriverdi, Orhan; Cay, Esra; Aydin, Mustafa; Miroglu, Cengiz

2009-01-01

The purpose of this study was to evaluate the use of virtual cystoscopy performed with multidetector computed tomography (CT) in patients with suspected bladder tumors and histories of bladder carcinoma operation. Thirty-six patients (29 men and 7 women) with a mean age of 66 years (range, 24-88 years) with suspected bladder tumors and histories of bladder carcinoma operation were included in this prospective study. Virtual cystoscopy was performed by 16-slice multidetector CT scanner. The bladder was filled with diluted contrast material solution through a Foley catheter. Then, all patients underwent conventional cystoscopy examination. Two reviewers found 18 lesions detected by virtual cystoscopy by consensus, whereas 19 lesions were depicted by conventional cystoscopy. At virtual and conventional cystoscopies, the conditions of 3 patients, 2 with chronic inflammations and 1 with foreign body reaction, were wrongly diagnosed as tumors. At conventional cystoscopy, one patient's result was wrongly interpreted as normal. In pathologic evaluation, all tumors were diagnosed as transitional cell carcinoma. Bladder tumor can be noninvasively diagnosed using virtual cystoscopy. Use of virtual cystoscopy should be considered inpatients who present with hematuria or have histories of bladder carcinoma operation and are for follow-up because of its lesser complication risk and its being a less invasive, easily applied procedure without need of anesthesia. In the future, owing to the development of the CT technology and image processing technique, virtual cystoscopy may have a part in the detection of bladder cancer.

[How practical guidelines can be applied in poor countries? Example of the introduction of a bronchoscopy unit in Cambodia].

Science.gov (United States)

Couraud, S; Chan, S; Avrillon, V; Horn, K; Try, S; Gérinière, L; Perrot, É; Guichon, C; Souquet, P-J; Ny, C

2013-10-01

According to UN, Cambodia is one of the poorest countries in the World. Respiratory diseases are current public health priorities. In this context, a new bronchoscopy unit (BSU) was created in the respiratory medicine department of Preah Kossamak hospital (PKH) thanks to a tight cooperation between a French and a Cambodian team. Aim of this study was to describe conditions of introduction of this equipment. Two guidelines for practice are available. They are respectively edited by the French and British societies of pulmonology. These guidelines were reviewed and compared to the conditions in which BS was introduced in PKH. Each item from guidelines was combined to a categorical value: "applied", "adapted" or "not applied". In 2009, 54 bronchoscopies were performed in PKH, mainly for suspicion of infectious or tumour disease. In total, 52% and 46% of the French and British guideline items respectively were followed in this Cambodian unit. Patient safety items are those highly followed. By contrast "staff safety" items were those weakly applied. Implementation of EBS in developing countries seems feasible in good conditions of quality and safety for patients. However, some recommendations cannot be applied due to local conditions. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Image-based path planning for automated virtual colonoscopy navigation

Science.gov (United States)

Hong, Wei

2008-03-01

Virtual colonoscopy (VC) is a noninvasive method for colonic polyp screening, by reconstructing three-dimensional models of the colon using computerized tomography (CT). In virtual colonoscopy fly-through navigation, it is crucial to generate an optimal camera path for efficient clinical examination. In conventional methods, the centerline of the colon lumen is usually used as the camera path. In order to extract colon centerline, some time consuming pre-processing algorithms must be performed before the fly-through navigation, such as colon segmentation, distance transformation, or topological thinning. In this paper, we present an efficient image-based path planning algorithm for automated virtual colonoscopy fly-through navigation without the requirement of any pre-processing. Our algorithm only needs the physician to provide a seed point as the starting camera position using 2D axial CT images. A wide angle fisheye camera model is used to generate a depth image from the current camera position. Two types of navigational landmarks, safe regions and target regions are extracted from the depth images. Camera position and its corresponding view direction are then determined using these landmarks. The experimental results show that the generated paths are accurate and increase the user comfort during the fly-through navigation. Moreover, because of the efficiency of our path planning algorithm and rendering algorithm, our VC fly-through navigation system can still guarantee 30 FPS.

Virtual 3D planning of tracheostomy placement and clinical applicability of 3D cannula design: a three-step study.

Science.gov (United States)

de Kleijn, Bertram J; Kraeima, Joep; Wachters, Jasper E; van der Laan, Bernard F A M; Wedman, Jan; Witjes, M J H; Halmos, Gyorgy B

2018-02-01

We aimed to investigate the potential of 3D virtual planning of tracheostomy tube placement and 3D cannula design to prevent tracheostomy complications due to inadequate cannula position. 3D models of commercially available cannula were positioned in 3D models of the airway. In study (1), a cohort that underwent tracheostomy between 2013 and 2015 was selected (n = 26). The cannula was virtually placed in the airway in the pre-operative CT scan and its position was compared to the cannula position on post-operative CT scans. In study (2), a cohort with neuromuscular disease (n = 14) was analyzed. Virtual cannula placing was performed in CT scans and tested if problems could be anticipated. Finally (3), for a patient with Duchenne muscular dystrophy and complications of conventional tracheostomy cannula, a patient-specific cannula was 3D designed, fabricated, and placed. (1) The 3D planned and post-operative tracheostomy position differed significantly. (2) Three groups of patients were identified: (A) normal anatomy; (B) abnormal anatomy, commercially available cannula fits; and (C) abnormal anatomy, custom-made cannula, may be necessary. (3) The position of the custom-designed cannula was optimal and the trachea healed. Virtual planning of the tracheostomy did not correlate with actual cannula position. Identifying patients with abnormal airway anatomy in whom commercially available cannula cannot be optimally positioned is advantageous. Patient-specific cannula design based on 3D virtualization of the airway was beneficial in a patient with abnormal airway anatomy.

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

STUDY ON VIRTUAL COLONOSCOPY

Directory of Open Access Journals (Sweden)

Aithagani Rama Chandraiah

2016-10-01

Full Text Available BACKGROUND Current options available in the investigations of colorectal carcinoma include screening using digital rectal examination, sigmoidoscopy, barium enema and fiberoptic colonoscopy, virtual colonoscopy. The aim of the study was to prospectively evaluate patient acceptance of virtual colonoscopy compared with that of conventional colonoscopy when performed in patients with or suspected of having colorectal disease. MATERIALS AND METHODS The study had been conducted on patients attending Department of Radiology for a period of 1 year. Patients with primary or secondary complaints of pain abdomen, lump in abdomen, bleeding per rectum, loose motions/constipation, altered bowel habits, loss of appetite and weight and anaemia, so total number of cases were 51. RESULTS In our study, the patients were in age groups of 21-70 years. Both sexes were represented in our study. Male preponderance was noted in 51 patients. Cases of adenoma were more commonly found 37 (72.78%. The sensitivity of the CT colonography for the polyps more than 10 mm is 100%, polyps 6-9 mm is 90%, less than 6 mm is 80%. Our study consists of 51 patients; among them, 30 patients showed acceptance for CT colonography, 10 patients for optical colonoscopy. Our study consists of 51 patients, the polyps (more than 10 mm detected in 2D viewing were 24, 2D and 3D viewing of 24, the polyps (less than 10 mm detected in 2D viewing were 15, 2D and 3D viewing were 17. 3D viewing resulted in increased sensitivity for identification of patients with larger polyps more than 1 cm, (70-85% sensitivity and patients with smaller polyps less than 1 cm (increased sensitivity 75-88%. CONCLUSIONS Multislice CT (64 colonography is a good alternative to other colorectal screening tests because it has high sensitivity for polyps 10 mm or more in diameter is relatively safe, clinical effective, minimally invasive, cost effective and filter for therapeutic optical colonoscopy.

Prospective study of device-related complications in intensive care unit detected by virtual autopsy.

Science.gov (United States)

Wichmann, D; Heinemann, A; Zähler, S; Vogel, H; Höpker, W; Püschel, K; Kluge, S

2018-06-01

There has been increasing use of invasive techniques, such as extracorporeal organ support, in intensive care units (ICU), and declining autopsy rates. Thus, new measures are needed to maintain high-quality standards. We investigated the potential of computed tomography (CT)-based virtual autopsy to substitute for medical autopsy in this setting. We investigated the potential of virtual autopsy by post-mortem CT to identify complications associated with medical devices in a prospective study of patients who had died in the ICU. Clinical records were reviewed to determine the number and types of medical devices used, and findings from medical and virtual autopsies, related and unrelated to the medical devices, were compared. Medical and virtual autopsies could be performed in 61 patients (Group M/V), and virtual autopsy only in 101 patients (Group V). In Group M/V, 41 device-related complications and 30 device malpositions were identified, but only with a low inter-method agreement. Major findings unrelated to a device were identified in about 25% of patients with a high level of agreement between methods. In Group V, 8 device complications and 36 device malpositions were identified. Device-related complications are frequent in ICU patients. Virtual and medical autopsies showed clear differences in the detection of complications and device malpositions. Both methods should supplement each other rather than one alone for quality control of medical devices in the ICU. Further studies should focus on the identification of special patient populations in which virtual autopsy might be of particular benefit. NCT01541982. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Bongers, Malte N.; Schabel, Christoph; Tsiflikas, Ilias; Ketelsen, Dominik; Mangold, Stefanie; Claussen, Claus D.; Nikolaou, Konstantin; Thomas, Christoph; Krauss, Bernhard

2015-01-01

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.)

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.)

The feasibility of endoscopy-CT image registration in the head and neck without prospective endoscope tracking.

Directory of Open Access Journals (Sweden)

W Scott Ingram

Full Text Available Endoscopic examinations are frequently-used procedures for patients with head and neck cancer undergoing radiotherapy, but radiation treatment plans are created on computed tomography (CT scans. Image registration between endoscopic video and CT could be used to improve treatment planning and analysis of radiation-related normal tissue toxicity. The purpose of this study was to explore the feasibility of endoscopy-CT image registration without prospective physical tracking of the endoscope during the examination.A novel registration technique called Location Search was developed. This technique uses physical constraints on the endoscope's view direction to search for the virtual endoscope coordinates that maximize the similarity between the endoscopic video frame and the virtual endoscopic image. Its performance was tested on phantom and patient images and compared to an established registration technique, Frame-To-Frame Tracking.In phantoms, Location Search had average registration errors of 0.55 ± 0.60 cm for point measurements and 0.29 ± 0.15 cm for object surface measurements. Frame-To-Frame Tracking achieved similar results on some frames, but it failed on others due to the virtual endoscope becoming lost. This weakness was more pronounced in patients, where Frame-To-Frame tracking could not make it through the nasal cavity. On successful patient video frames, Location Search was able to find endoscope positions with an average distance of 0.98 ± 0.53 cm away from the ground truth positions. However, it failed on many frames due to false similarity matches caused by anatomical structural differences between the endoscopic video and the virtual endoscopic images.Endoscopy-CT image registration without prospective physical tracking of the endoscope is possible, but more development is required to achieve an accuracy suitable for clinical translation.

Variations in tumor size and position due to irregular breathing in 4D-CT: A simulation study

International Nuclear Information System (INIS)

Sarker, Joyatee; Chu, Alan; Mui, Kit; Wolfgang, John A.; Hirsch, Ariel E.; Chen, George T. Y.; Sharp, Gregory C.

2010-01-01

Purpose: To estimate the position and volume errors in 4D-CT caused by irregular breathing. Methods: A virtual 4D-CT scanner was designed to reproduce axial mode scans with retrospective resorting. This virtual scanner creates an artificial spherical tumor based on the specifications of the user, and recreates images that might be produced by a 4D-CT scanner using a patient breathing waveform. 155 respiratory waveforms of patients were used to test the variability of 4D-CT scans. Each breathing waveform was normalized and scaled to 1, 2, and 3 cm peak-to-peak motion, and artificial tumors with 2 and 4 cm radius were simulated for each scaled waveform. The center of mass and volume of resorted 4D-CT images were calculated and compared to the expected values of center of mass and volume for the artificial tumor. Intrasubject variability was investigated by running the virtual scanner over different subintervals of each patient's breathing waveform. Results: The average error in the center of mass location of an artificial tumor was less than 2 mm standard deviation for 2 cm motion. The corresponding average error in volume was less than 4%. In the worst-case scenarios, a center of mass error of 1.0 cm standard deviation and volume errors of 30%-60% at inhale were found. Systematic errors were observed in a subset of patients due to irregular breathing, and these errors were more pronounced when the tumor volume is smaller. Conclusions: Irregular breathing during 4D-CT simulation causes systematic errors in volume and center of mass measurements. These errors are small but depend on the tumor size, motion amplitude, and degree of breathing irregularity.

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.)

CT-assisted agile manufacturing

Science.gov (United States)

Stanley, James H.; Yancey, Robert N.

1996-11-01

The next century will witness at least two great revolutions in the way goods are produced. First, workers will use the medium of virtual reality in all aspects of marketing, research, development, prototyping, manufacturing, sales and service. Second, market forces will drive manufacturing towards small-lot production and just-in-time delivery. Already, we can discern the merging of these megatrends into what some are calling agile manufacturing. Under this new paradigm, parts and processes will be designed and engineered within the mind of a computer, tooled and manufactured by the offspring of today's rapid prototyping equipment, and evaluated for performance and reliability by advanced nondestructive evaluation (NDE) techniques and sophisticated computational models. Computed tomography (CT) is the premier example of an NDE method suitable for future agile manufacturing activities. It is the only modality that provides convenient access to the full suite of engineering data that users will need to avail themselves of computer- aided design, computer-aided manufacturing, and computer- aided engineering capabilities, as well as newly emerging reverse engineering, rapid prototyping and solid freeform fabrication technologies. As such, CT is assured a central, utilitarian role in future industrial operations. An overview of this exciting future for industrial CT is presented.

Ultrathin bronchoscopy for solitary pulmonary lesions in a region endemic for tuberculosis: a randomised pilot trial.

Science.gov (United States)

Franzen, Daniel; Diacon, Andreas H; Freitag, Lutz; Schubert, Pawel T; Wright, Colleen A; Schuurmans, Macé M

2016-04-27

The evaluation of solitary pulmonary lesions (SPL) requires a balance between procedure-related morbidity and diagnostic yield, particularly in areas where tuberculosis (TB) is endemic. Data on ultrathin bronchoscopy (UB) for this purpose is limited. To evaluate feasibility and safety of UB compared to SB for diagnosis of SPL in a TB endemic region. In this prospective randomised trial we compared diagnostic yield and adverse events of UB with standard-size bronchoscopy (SB), both combined with fluoroscopy, in a cohort of patients with SPL located beyond the visible range of SB. We included 40 patients (mean age 55.2 years, 45 % male) with malignant SPL (n = 16; 40 %), tuberculous SPL (n = 11; 27.5 %) and other benign SPL (n = 13; 32.5 %). Mean procedure time in UB and SB was 30.6 and 26.0 min, respectively (p = 0.15). By trend, adverse events were recorded more often with UB than with SB (30.0 vs. 5.0 %, p = 0.091), including extensive coughing (n = 2), blocked working channel (n = 2), and arterial hypertension requiring therapeutic intervention (n = 1), all with UB. The overall diagnostic yield of UB compared to SB was 55.0 % vs. 80.0 %, respectively (p = 0.18). Sensitivity for the diagnosis of malignancy of UB and SB was 50.0 % and 62.5 %, respectively (p = 0.95). UB is not superior to SB for the evaluation of SPL in a region endemic with tuberculosis, when combined with fluoroscopic guidance only. ClinicalTrials.gov (Identifier: NCT02490059 ).

Detection of small-bowel tumours with CT enteroclysis using carbon dioxide and virtual enteroscopy. A preliminary study

International Nuclear Information System (INIS)

Dohan, Anthony; Boudiaf, Mourad; Dautry, Raphael; Dray, Xavier; Samaha, Elia; Cellier, Christophe; Camus, Marine; Eveno, Clarisse; Soyer, Philippe

2018-01-01

The aim of this prospective study was to evaluate the feasibility, tolerance and performance of virtual enteroscopy (VE) using carbon dioxide for small-bowel distension in patients with suspected small-bowel tumours (SBTs). After IRB approval, 17 patients with suspected SBTs were prospectively included. Radiation dose was compared to 34 matched patients (2 for 1) for age, gender and body weight, who had undergone CT-enteroclysis with neutral contrast (CTE). Performance of VE was evaluated through comparison with the current standard of reference, including surgery and/or enteroscopy and/or follow-up. Tolerance was excellent in 16/17 patients (94%). The radiation dose was lower for VE than for CTE (533 ± 282 vs. 974 ± 505 mGy.cm; p = 0.002). With VE, a total of 25 polyps >5 mm in size were depicted in 12/17 patients. On a per-lesion analysis, sensitivity and positive predictive value of VE were 92.0% and 92.0%, respectively. On a per-segment analysis VE had a sensitivity and specificity of 95.0% and 87.0%, respectively. Our preliminary study suggests that VE is a feasible and well-tolerated technique with high sensitivity and specificity for the diagnosis of SBT. (orig.)

Detection of small-bowel tumours with CT enteroclysis using carbon dioxide and virtual enteroscopy. A preliminary study

Energy Technology Data Exchange (ETDEWEB)

Dohan, Anthony [Hopital Lariboisiere - Assistance Publique-Hopitaux de Paris, Department of Body and Interventional Imaging, Paris (France); Universite Sorbonne Paris Cite, Paris Diderot, INSERM UMR 965, Paris (France); Boudiaf, Mourad; Dautry, Raphael [Hopital Lariboisiere - Assistance Publique-Hopitaux de Paris, Department of Body and Interventional Imaging, Paris (France); Dray, Xavier [Department of Digestive Diseases, Hopital Saint-Antoine, Assistance Publique-Hopitaux de Paris, Paris (France); Sorbonne Universite, Paris (France); Samaha, Elia [European Georges Pompidou Hospital, Assistance Publique-Hopitaux de Paris, Gastroenterology and Endoscopy Unit, Paris (France); Cellier, Christophe [European Georges Pompidou Hospital, Assistance Publique-Hopitaux de Paris, Gastroenterology and Endoscopy Unit, Paris (France); Universite Sorbonne Paris Cite, Paris Descartes, Paris (France); Camus, Marine [Universite Sorbonne Paris Cite, Paris Descartes, Paris (France); Hopital Cochin - Assistance Publique-Hopitaux de Paris, Department of Gastroenterology, Paris (France); Eveno, Clarisse [Universite Sorbonne Paris Cite, Paris Diderot, INSERM UMR 965, Paris (France); Hopital Lariboisiere - Assistance Publique-Hopitaux de Paris, Department of Surgical Oncologic and Digestive Unit, Paris (France); Soyer, Philippe [Universite Sorbonne Paris Cite, Paris Diderot, INSERM UMR 965, Paris (France); Hopital Cochin - Assistance Publique-Hopitaux de Paris, Department of Body and Interventional Imaging, Paris (France)

2018-01-15

The aim of this prospective study was to evaluate the feasibility, tolerance and performance of virtual enteroscopy (VE) using carbon dioxide for small-bowel distension in patients with suspected small-bowel tumours (SBTs). After IRB approval, 17 patients with suspected SBTs were prospectively included. Radiation dose was compared to 34 matched patients (2 for 1) for age, gender and body weight, who had undergone CT-enteroclysis with neutral contrast (CTE). Performance of VE was evaluated through comparison with the current standard of reference, including surgery and/or enteroscopy and/or follow-up. Tolerance was excellent in 16/17 patients (94%). The radiation dose was lower for VE than for CTE (533 ± 282 vs. 974 ± 505 mGy.cm; p = 0.002). With VE, a total of 25 polyps >5 mm in size were depicted in 12/17 patients. On a per-lesion analysis, sensitivity and positive predictive value of VE were 92.0% and 92.0%, respectively. On a per-segment analysis VE had a sensitivity and specificity of 95.0% and 87.0%, respectively. Our preliminary study suggests that VE is a feasible and well-tolerated technique with high sensitivity and specificity for the diagnosis of SBT. (orig.)

Visuomotor adaptation in head-mounted virtual reality versus conventional training

Science.gov (United States)

Anglin, J. M.; Sugiyama, T.; Liew, S.-L.

2017-01-01

Immersive, head-mounted virtual reality (HMD-VR) provides a unique opportunity to understand how changes in sensory environments affect motor learning. However, potential differences in mechanisms of motor learning and adaptation in HMD-VR versus a conventional training (CT) environment have not been extensively explored. Here, we investigated whether adaptation on a visuomotor rotation task in HMD-VR yields similar adaptation effects in CT and whether these effects are achieved through similar mechanisms. Specifically, recent work has shown that visuomotor adaptation may occur via both an implicit, error-based internal model and a more cognitive, explicit strategic component. We sought to measure both overall adaptation and balance between implicit and explicit mechanisms in HMD-VR versus CT. Twenty-four healthy individuals were placed in either HMD-VR or CT and trained on an identical visuomotor adaptation task that measured both implicit and explicit components. Our results showed that the overall timecourse of adaption was similar in both HMD-VR and CT. However, HMD-VR participants utilized a greater cognitive strategy than CT, while CT participants engaged in greater implicit learning. These results suggest that while both conditions produce similar results in overall adaptation, the mechanisms by which visuomotor adaption occurs in HMD-VR appear to be more reliant on cognitive strategies. PMID:28374808

Virtual colonoscopy in paediatric patients

International Nuclear Information System (INIS)

Carrascosa, Patricia; Lopez, Elba Martin; Capunay, Carlos; Vallejos, Javier; Carrascosa, Jorge

2010-01-01

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.

Detection of unknown primary neuroendocrine tumours (CUP-NET) using 68Ga-DOTA-NOC receptor PET/CT

International Nuclear Information System (INIS)

Prasad, Vikas; Baum, Richard P.; Ambrosini, Valentina; Fanti, Stefano; Hommann, Merten; Hoersch, Dieter

2010-01-01

This bi-centric study aimed to determine the role of receptor PET/CT using 68 Ga-DOTA-NOC in the detection of undiagnosed primary sites of neuroendocrine tumours (NETs) and to understand the molecular behaviour of the primarily undiagnosed tumours. Overall 59 patients (33 men and 26 women, age: 65 ± 9 years) with documented NET and unknown primary were enrolled. PET/CT was performed after injection of approximately 100 MBq (46-260 MBq) of 68 Ga-DOTA-NOC. The maximum standardised uptake values (SUV max ) were calculated and compared with SUV max in known pancreatic NET (pNET) and ileum/jejunum/duodenum (SI-NET). The results of PET/CT were also correlated with CT alone. In 35 of 59 patients (59%), 68 Ga-DOTA-NOC PET/CT localised the site of the primary: ileum/jejunum (14), pancreas (16), rectum/colon (2), lungs (2) and paraganglioma (1). CT alone (on retrospective analyses) confirmed the findings in 12 of 59 patients (20%). The mean SUV max of identified previously unknown pNET and SI-NET were 18.6 ± 9.8 (range: 7.8-34.8) and 9.1 ± 6.0 (range: 4.2-27.8), respectively. SUV max in patients with previously known pNET and SI-NET were 26.1 ± 14.5 (range: 8.7-42.4) and 11.3 ± 3.7 (range: 5.6-17.9). The SUV max of the unknown pNET and SI-NET were significantly lower (p 68 Ga-DOTA-NOC receptor PET/CT, 6 of 59 patients were operated and the primary was removed (4 pancreatic, 1 ileal and 1 rectal tumour) resulting in a management change in approximately 10% of the patients. In the remaining 29 patients, because of the far advanced stage of the disease (due to distant metastases), the primary tumours were not operated. Additional histopathological sampling was available from one patient with bronchial carcinoid (through bronchoscopy). Our data indicate that 68 Ga-DOTA-NOC PET/CT is highly superior to 111 In-OctreoScan (39% detection rate for CUP according to the literature) and can play a major role in the management of patients with CUP-NET. (orig.)

CT and MRI techniques for imaging around orthopedic hardware

Energy Technology Data Exchange (ETDEWEB)

Do, Thuy Duong; Skornitzke, Stephan; Weber, Marc-Andre [Heidelberg Univ. (Germany). Dept. of Clinical Radiology; Sutter, Reto [Uniklinik Balgrist, Zurich (Switzerland). Radiology

2018-01-15

Orthopedic hardware impairs image quality in cross-sectional imaging. With an increasing number of orthopedic implants in an aging population, the need to mitigate metal artifacts in computed tomography and magnetic resonance imaging is becoming increasingly relevant. This review provides an overview of the major artifacts in CT and MRI and state-of-the-art solutions to improve image quality. All steps of image acquisition from device selection, scan preparations and parameters to image post-processing influence the magnitude of metal artifacts. Technological advances like dual-energy CT with the possibility of virtual monochromatic imaging (VMI) and new materials offer opportunities to further reduce artifacts in CT and MRI. Dedicated metal artifact reduction sequences contain algorithms to reduce artifacts and improve imaging of surrounding tissue and are essential tools in orthopedic imaging to detect postoperative complications in early stages.

3D visualisation of the middle ear and adjacent structures using reconstructed multi-slice CT datasets, correlating 3D images and virtual endoscopy to the 2D cross-sectional images

International Nuclear Information System (INIS)

Rodt, T.; Ratiu, P.; Kacher, D.F.; Anderson, M.; Jolesz, F.A.; Kikinis, R.; Becker, H.; Bartling, S.

2002-01-01

The 3D imaging of the middle ear facilitates better understanding of the patient's anatomy. Cross-sectional slices, however, often allow a more accurate evaluation of anatomical structures, as some detail may be lost through post-processing. In order to demonstrate the advantages of combining both approaches, we performed computed tomography (CT) imaging in two normal and 15 different pathological cases, and the 3D models were correlated to the cross-sectional CT slices. Reconstructed CT datasets were acquired by multi-slice CT. Post-processing was performed using the in-house software ''3D Slicer'', applying thresholding and manual segmentation. 3D models of the individual anatomical structures were generated and displayed in different colours. The display of relevant anatomical and pathological structures was evaluated in the greyscale 2D slices, 3D images, and the 2D slices showing the segmented 2D anatomy in different colours for each structure. Correlating 2D slices to the 3D models and virtual endoscopy helps to combine the advantages of each method. As generating 3D models can be extremely time-consuming, this approach can be a clinically applicable way of gaining a 3D understanding of the patient's anatomy by using models as a reference. Furthermore, it can help radiologists and otolaryngologists evaluating the 2D slices by adding the correct 3D information that would otherwise have to be mentally integrated. The method can be applied to radiological diagnosis, surgical planning, and especially, to teaching. (orig.)

Virtual Reality Training for Upper Extremity in Subacute Stroke (VIRTUES)

DEFF Research Database (Denmark)

Brunner, Iris; Skouen, Jan Sture; Hofstad, Håkon

2017-01-01

Objective: To compare the effectiveness of upper extremity virtual reality rehabilitation training (VR) to time-matched conventional training (CT) in the subacute phase after stroke. Methods: In this randomized, controlled, single-blind phase III multicenter trial, 120 participants with upper...... extremity motor impairment within 12 weeks after stroke were consecutively included at 5 rehabilitation institutions. Participants were randomized to either VR or CT as an adjunct to standard rehabilitation and stratified according to mild to moderate or severe hand paresis, defined as $20 degrees wrist...... were assessed at baseline, after intervention, and at the 3-month follow-up. Results: Mean time from stroke onset for the VR group was 35 (SD 21) days and for the CT group was 34 (SD 19) days. There were no between-group differences for any of the outcome measures. Improvement of upper extremity motor...

Exploring metal artifact reduction using dual-energy CT with pre-metal and post-metal implant cadaver comparison: are implant specific protocols needed?

NARCIS (Netherlands)

Wellenberg, Ruud H. H.; Donders, Johanna C. E.; Kloen, Peter; Beenen, Ludo F. M.; Kleipool, Roeland P.; Maas, Mario; Streekstra, Geert J.

2017-01-01

To quantify and optimize metal artifact reduction using virtual monochromatic dual-energy CT for different metal implants compared to non-metal reference scans. Dual-energy CT scans of a pair of human cadaver limbs were acquired before and after implanting a titanium tibia plate, a stainless-steel

A prospective study to determine the need for physical simulation following virtual simulation

International Nuclear Information System (INIS)

Valicenti, R.K.; Waterman, F.M.; Corn, B.W.; Sweet, J.; Curran, W.J.

1996-01-01

Purpose: Virtual simulation is CT based planning utilizing computed digitally reconstructed radiographs (DRRs) in a manner similar to conventional fluoroscopic simulation. However, conventional or physical simulation is still widely used to assure precise implementation of the devised plan. To evaluate the need for performing physical simulation, we prospectively studied patients undergoing virtual simulation who either had or did not have a subsequent physical simulation. Materials and Methods: From July, 1995 to February, 1996, 48 patients underwent conformal 4-field radiation therapy for prostate cancer using a commercial grade spiral CT simulator. All patients were immobilized in a foam body cast and positioned by using a fiducial laser marking system. Following prostate and seminal vesicle definition on a slice-by-slice basis, virtual simulation was performed. The isocenter defined by this process was marked on both the patient and the immobilization device before leaving the CT simulator room. The isocenter position of the devised plan was evaluated by three verification methods: physical simulation, first day treatment port filming, and port filming immediately following physical simulation. Simulator radiographs and port films were compared against DRRs for x, y, and z deviations of the isocenter. These deviations were used as a measure of the implementation precision achieved by each verification method. Results: Thirty-seven patients underwent physical simulation and first day port filming. Eleven had first day treatment verification films only and never had a physical simulation. A total of 79 simulator radiographs and 126 first day treatment port films were reviewed. The tabulation of all deviations is as follows: There was significantly more setup error (≥ 5 mm) observed when the devised treatment was implemented in the treatment room as opposed to the physical simulator. The physical simulator did not lead to a significant reduction in setup error

Spiral CT colonography in inflammatory bowel disease

International Nuclear Information System (INIS)

Tarjan, Zsolt; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K.

2000-01-01

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

3D printing from cardiovascular CT: a practical guide and review

Science.gov (United States)

Birbara, Nicolette S.; Hussain, Tarique; Greil, Gerald; Foley, Thomas A.; Pather, Nalini

2017-01-01

Current cardiovascular imaging techniques allow anatomical relationships and pathological conditions to be captured in three dimensions. Three-dimensional (3D) printing, or rapid prototyping, has also become readily available and made it possible to transform virtual reconstructions into physical 3D models. This technology has been utilised to demonstrate cardiovascular anatomy and disease in clinical, research and educational settings. In particular, 3D models have been generated from cardiovascular computed tomography (CT) imaging data for purposes such as surgical planning and teaching. This review summarises applications, limitations and practical steps required to create a 3D printed model from cardiovascular CT. PMID:29255693

Evaluation of a radiographer tele-training programme in the interpretation of CT Colonography

DEFF Research Database (Denmark)

Lauridsen, Carsten Ammitzbøl; Lefere, Philippe

2012-01-01

Colorectal cancer is one of the most common, and deadly human cancers. By early identifi cation of suspect lesions, screening has the potential to reduce mortality. Colonos- copy remains the screening gold standard, but “virtual colonoscopy“ or CT-colonography (CTC) has been shown to generate...

Study of the usefulness of large intestine screening inspections using multi-slice CT (MSCT)

International Nuclear Information System (INIS)

Yamasaki, Michihiro; Nonogaki, Hidehiko; Hara, Koji; Naruse, Yutaka; Hara, Hiroto; Suematsu, Seiji; Yanase, Tadahiko; Otou, Taiji

2005-01-01

CT-colonography (CT-C), a new diagnostic imaging technique for cancer of the large intestine-which is increasing rapidly owing to westernized eating habits-has advanced from the developmental stage to the stage of practical application, thanks to progress in MSCT and workstation development. Therefore, based on the results of CT-C application using 16 lines of MSCT to a screening test, we reviewed the usefulness of CT-C in our clinic. We supplemented defective depiction, and found that change of position was effective for virtual image exclusion. We consider that CT-C can support diagnosis if the target of screening tests is a polypoid lesion of more than 6 mm. In addition, it is expected that the number of examinations performed during office visits will increase because of the decreased invasiveness of the procedure, its lack of pain, and its ability to provide early lesion detection. (author)

Colonic polyp detection method from 3D abdominal CT images based on local intensity analysis

International Nuclear Information System (INIS)

Oda, M.; Nakada, Y.; Kitasaka, T.; Mori, K.; Suenaga, Y.; Takayama, T.; Takabatake, H.; Mori, M.; Natori, H.; Nawano, S.

2007-01-01

This paper presents a detection method of colonic polyps from 3D abdominal CT images based on local intensity analysis. Recently, virtual colonoscopy (VC) has widely received attention as a new colon diagnostic method. VC is considered as a less-invasive inspection method which reduces patient load. However, since the colon has many haustra and its shape is long and convoluted, a physician has to change the viewpoint and the viewing direction of the virtual camera of VC many times while diagnosis. Additionally, there is a risk to overlook lesions existing in blinded areas caused by haustra. This paper proposes an automated colonic polyp detection method from 3D abdominal CT images. Colonic polyps are located on the colonic wall. Their CT values are higher than those of colonic lumen regions and lower than those of fecal materials tagged by an X-ray opaque contrast agent. CT values inside polyps which exist outside the tagged fecal materials tend to gradually increase from outward to inward (blob-like structure). CT values inside polyps that exist inside the tagged fecal materials tend to gradually decrease from outward to inward (inv-blob-like structure). We employ the blob and the inv-blob structure enhancement filters based on the eigenvalues of the Hessian matrix to detect polyps using intensity characteristic of polyps. Connected components with low output values of the enhancement filter are eliminated in false positive reduction process. Small connected components are also eliminated. We applied the proposed method to 44 cases of abdominal CT images. Sensitivity for polyps of 6 mm or larger was 80% with 4.7 false positives per case. (orig.)

The evaluation of the quality of virtual non-enhanced CT of the kidney%肾脏能谱CT虚拟平扫的图像质量评价

Institute of Scientific and Technical Information of China (English)

彭波; 刘姝芩; 侯键; 张玉东; 谢明国

2017-01-01

目的:分析比较肾脏常规CT平扫与能谱CT虚拟平扫(VNC)的图像质量,以探讨肾脏能谱CT VNC替代常规CT平扫的可行性.方法:前瞻性搜集行CTU患者26例,所有患者均在常规平扫后开启能谱模式行肾脏动脉期、实质期及排泄期增强扫描,增强扫描图像经后处理分别获得6组VNC图像,即动脉期抑碘图、动脉期水基图、实质期抑碘图、实质期水基图、排泄期抑碘图、排泄期水基图,分别比较常规平扫与6组VNC的噪声、对比噪声比(CNR)、图像质量主观评分及有效辐射剂量.结果:常规平扫分别与6组VNC噪声比较,差异均无统计学意义(均P>0.05);常规平扫分别与6组VNC皮质CNR比较,均大于各期抑碘图(均P0.05);在图像质量主观评分上,6组VNC图像组间差异有统计学意义(P0.05). The difference of cortical CNR between VNC and plain scan was statistically significant (Piodine-suppressed image. The image quality of VNC was slightly worse than plain scan subjectively (P<0.05),with arterial phase iodine-suppressed image being scored the highest. The effective radiation dose was reduced about 27.89% compared to routine contrast enhanced urography CT. Conclusion:The image quality between the CNE and VNC are very high,so that the spectral CT virtual non-enhanced in the CT urinary tract contrast examination can basically replace the conventional CT scan,which can reduce the times of scanning,reduce the patient radiation dose and provide the possibility to further investigate the spectral CT's low dose radiation CT urography imaging scheme.

Generation of realistic virtual nodules based on three-dimensional spatial resolution in lung computed tomography: A pilot phantom study.

Science.gov (United States)

Narita, Akihiro; Ohkubo, Masaki; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

2017-10-01

The aim of this feasibility study using phantoms was to propose a novel method for obtaining computer-generated realistic virtual nodules in lung computed tomography (CT). In the proposed methodology, pulmonary nodule images obtained with a CT scanner are deconvolved with the point spread function (PSF) in the scan plane and slice sensitivity profile (SSP) measured for the scanner; the resultant images are referred to as nodule-like object functions. Next, by convolving the nodule-like object function with the PSF and SSP of another (target) scanner, the virtual nodule can be generated so that it has the characteristics of the spatial resolution of the target scanner. To validate the methodology, the authors applied physical nodules of 5-, 7- and 10-mm-diameter (uniform spheres) included in a commercial CT test phantom. The nodule-like object functions were calculated from the sphere images obtained with two scanners (Scanner A and Scanner B); these functions were referred to as nodule-like object functions A and B, respectively. From these, virtual nodules were generated based on the spatial resolution of another scanner (Scanner C). By investigating the agreement of the virtual nodules generated from the nodule-like object functions A and B, the equivalence of the nodule-like object functions obtained from different scanners could be assessed. In addition, these virtual nodules were compared with the real (true) sphere images obtained with Scanner C. As a practical validation, five types of laboratory-made physical nodules with various complicated shapes and heterogeneous densities, similar to real lesions, were used. The nodule-like object functions were calculated from the images of these laboratory-made nodules obtained with Scanner A. From them, virtual nodules were generated based on the spatial resolution of Scanner C and compared with the real images of laboratory-made nodules obtained with Scanner C. Good agreement of the virtual nodules generated from

Is there a role for virtual otoscopy in the preoperative assessment of the ossicular chain in chronic suppurative otitis media? Comparison of HRCT and virtual otoscopy with surgical findings

Energy Technology Data Exchange (ETDEWEB)

Pandey, A.K. [University of British Columbia, Department of Radiology, St. Paul Hospital, Vancouver, BC (Canada); Bapuraj, J.R. [University of Michigan, Division of Neuroradiology, Department of Radiology, University Hospital, Ann Arbor, MI (United States); Gupta, A.K. [Post Graduate Institute of Medical Education and Research, Department of Otolaryngology, Chandigarh (India); Khandelwal, N. [Post Graduate Institute of Medical Education and Research, Department of Radiodiagnosis, Chandigarh (India)

2009-06-15

The aim of this study was to assess the role of virtual otoscopy and 3D ossicular reconstruction in the preoperative assessment of the ossicles in chronic suppurative otitis media. Thirty three patients of chronic suppurative otitis media with conductive deafness (air-bone gap > 35 dB) were included in this prospective study. All patients underwent axial multidetector CT. The axial CT data set was utilized for multiplanar 2D reformations as well as virtual otoscopy (VO) and 3D reconstructions. The imaging findings on these two techniques were read independently by two radiologists with respect to different parts of the ossicular chain by using a three-point scoring system and were compared with surgical findings. Both imaging techniques had comparable accuracy for evaluation of larger ossicular parts. However, for evaluation of stapes superstructure, VO/3D images were more accurate (85.29%) than 2D images (76.97%). Assessment of the lenticular process and incudostapedial joint by HRCT and 2D reformatted images was not reliable (P > 0.1); however, significant correlation (P < 0.001) was present between VO/3D and the operative findings. Virtual otoscopy improves evaluation of the ossicular chain particularly that of smaller structures such as the lenticular process, incudostapedial joint and stapes superstructure which may influence decisions regarding planning of ossiculoplasty. (orig.)

Is there a role for virtual otoscopy in the preoperative assessment of the ossicular chain in chronic suppurative otitis media? Comparison of HRCT and virtual otoscopy with surgical findings

International Nuclear Information System (INIS)

Pandey, A.K.; Bapuraj, J.R.; Gupta, A.K.; Khandelwal, N.

2009-01-01

The aim of this study was to assess the role of virtual otoscopy and 3D ossicular reconstruction in the preoperative assessment of the ossicles in chronic suppurative otitis media. Thirty three patients of chronic suppurative otitis media with conductive deafness (air-bone gap > 35 dB) were included in this prospective study. All patients underwent axial multidetector CT. The axial CT data set was utilized for multiplanar 2D reformations as well as virtual otoscopy (VO) and 3D reconstructions. The imaging findings on these two techniques were read independently by two radiologists with respect to different parts of the ossicular chain by using a three-point scoring system and were compared with surgical findings. Both imaging techniques had comparable accuracy for evaluation of larger ossicular parts. However, for evaluation of stapes superstructure, VO/3D images were more accurate (85.29%) than 2D images (76.97%). Assessment of the lenticular process and incudostapedial joint by HRCT and 2D reformatted images was not reliable (P > 0.1); however, significant correlation (P < 0.001) was present between VO/3D and the operative findings. Virtual otoscopy improves evaluation of the ossicular chain particularly that of smaller structures such as the lenticular process, incudostapedial joint and stapes superstructure which may influence decisions regarding planning of ossiculoplasty. (orig.)

Application of virtual reality techniques in preoperative surgical planning for intracranial anterior circulation aneurysms

Directory of Open Access Journals (Sweden)

Shou-sen WANG

2012-05-01

Full Text Available Objective 　To investigate the value of virtual reality (VR technique in the surgical planning for anterior circulation aneurysms of Willis circle. Methods 　A total of 50 patients with 57 aneurysms confirmed by CT angiography in the anterior circle of Willis were enrolled in this study. In preoperative Hunt-Hess scale, grade Ⅰ was designated in 7 patients, grade Ⅱ in 22, grade Ⅲ in 17, grade Ⅳ in 3, grade Ⅴ in 1 patient. Among the aneurysms, 16 were small (≤5mm in diameter, 28 medium (5-15mm, 10 large (15-25mm and 3 giant (≥25mm in size. The thin-slice head scanning data were achieved by 64-slice spiral CT machine. These data was then transferred into Dextroscope image workstation. The virtual imaging system generated clear and vivid virtual images. We compared the findings between simulation surgical operation and actual operation. Results 　VR system make the operator felt "personally on the scene" and was able to communicate with the imaging. It could not only visually display the anatomical structures in three dimensions, but also could simulate some surgical procedures, which basically simulated the same outcome of actual operation. All the 50 patients were successfully treated by microsurgical clipping of main aneurysmal or contributory aneurysmal necks. Conclusions 　The surgeons is able to be more confident, and the identification for the complex vascular abnormality is improved by planning operative procedure in virtual-reality environment. The virtual-reality system makes the actual operative procedure more concise, thus it is of positive value in surgery for intracranial aneurysm.

Evaluation of the appreciation of virtual teeth with and without pathology.

Science.gov (United States)

de Boer, I R; Lagerweij, M D; Wesselink, P R; Vervoorn, J M

2015-05-01

Virtual teeth with and without tooth pathology have been developed for use in a virtual learning environment in dental education. The objective of this study was to evaluate the appearance of these virtual teeth for use in dental education and to compare them with contemporary educational models, such as plastic teeth (Frasaco GmbH) and extracted human teeth. Six sets of photographs representing six different teeth were shown to dentists, teachers (dentists) and dental students (bachelor's and master's degree students). Each set consisted of 15 pictures showing five views of the extracted human tooth, the similar virtual tooth and the plastic tooth. The five views represented the mesial, distal, occlusal, buccal and lingual surfaces. The virtual tooth was the same as the extracted tooth (scanned with a cone beam CT, coloured and edited in ColorMapEditor(®) ), and the plastic tooth presented the best possible match to the extracted tooth. The participants were asked to rate the appearance of the virtual teeth (overall and in terms of caries, restoration and colours), whether the virtual or plastic teeth resembled the extracted teeth better and from which teeth they expected to learn the most (extracted, virtual or plastic). Each group of participants found that the virtual teeth resembled the extracted teeth more than they resembled the plastic teeth; 71% of the participants expected to learn more from the virtual teeth than from the plastic teeth. The results show that the appearance of the virtual teeth was considered more realistic than the appearance of the plastic teeth. The expectation was that the learning opportunities of the virtual teeth are better than of the plastic teeth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

TU-AB-202-12: A Novel Method to Map Endoscopic Video to CT for Treatment Planning and Toxicity Analysis in Radiation Therapy

International Nuclear Information System (INIS)

Ingram, W; Yang, J; Beadle, B; Wendt, R; Rao, A; Court, L

2016-01-01

Purpose: Endoscopic examinations are routine procedures for head-and-neck cancer patients. Our goal is to develop a method to map the recorded video to CT, providing valuable information for radiotherapy treatment planning and toxicity analysis. Methods: We map video frames to CT via virtual endoscopic images rendered at the real endoscope’s CT-space coordinates. We developed two complementary methods to find these coordinates by maximizing real-to-virtual image similarity:(1)Endoscope Tracking: moves the virtual endoscope frame-by-frame until the desired frame is reached. Utilizes prior knowledge of endoscope coordinates, but sensitive to local optima. (2)Location Search: moves the virtual endoscope along possible paths through the volume to find the desired frame. More robust, but more computationally expensive. We tested these methods on clay phantoms with embedded markers for point mapping and protruding bolus material for contour mapping, and we assessed them qualitatively on three patient exams. For mapped points we calculated 3D-distance errors, and for mapped contours we calculated mean absolute distances (MAD) from CT contours. Results: In phantoms, Endoscope Tracking had average point error=0.66±0.50cm and average bolus MAD=0.74±0.37cm for the first 80% of each video. After that the virtual endoscope got lost, increasing these values to 4.73±1.69cm and 4.06±0.30cm. Location Search had point error=0.49±0.44cm and MAD=0.53±0.28cm. Point errors were larger where the endoscope viewed the surface at shallow angles<10 degrees (1.38±0.62cm and 1.22±0.69cm for Endoscope Tracking and Location Search, respectively). In patients, Endoscope Tracking did not make it past the nasal cavity. However, Location Search found coordinates near the correct location for 70% of test frames. Its performance was best near the epiglottis and in the nasal cavity. Conclusion: Location Search is a robust and accurate technique to map endoscopic video to CT. Endoscope

Split-bolus CT-urography using dual-energy CT: Feasibility, image quality and dose reduction

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, Mitsuru, E-mail: m2rbimn@gmail.com [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Kawai, Tatsuya; Ito, Masato; Ogawa, Masaki [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Ohashi, Kazuya [Nagoya City University Hospital, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Hara, Masaki; Shibamoto, Yuta [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan)

2012-11-15

Purpose: To prospectively evaluate the feasibility of dual-energy (DE) split-bolus CT-urography (CTU) and the quality of virtual non-enhanced images (VNEI) and DE combined nephrographic-excretory phase images (CNEPI), and to estimate radiation dose reduction if true non-enhanced images (TNEI) could be omitted. Patients and methods: Between August and September 2011, 30 consecutive patients with confirmed or suspected urothelial cancer or with hematuria underwent DE CT. Single-energy TNEI and DE CNEPI were obtained. VNEI was reconstructed from CNEPI. Image quality of CNEPI and VNEI was evaluated using a 5-point scale. The attenuation of urine in the bladder on TNEI and VNEI was measured. The CT dose index volume (CTDI (vol)) of the two scans was recorded. Results: The mean image quality score of CNEPI and VNEI was 4.7 and 3.3, respectively. The mean differences in urine attenuation between VNEI and TNEI were 14 {+-} 15 [SD] and -16 {+-} 29 in the anterior and posterior parts of the bladder, respectively. The mean CTDI (vol) for TNEI and CNEPI was 11.8 and 10.9 mGy, respectively. Omission of TNEI could reduce the total radiation dose by 52%. Conclusion: DE split-bolus CTU is technically feasible and can reduce radiation exposure; however, an additional TNEI scan is necessary when the VNEI quality is poor or quantitative evaluation of urine attenuation is required.

PET/CT Imaging and Radioimmunotherapy of Prostate Cancer

DEFF Research Database (Denmark)

Bouchelouche, Kirsten; Tagawa, Scott T; Goldsmith, Stanley J

2011-01-01

disease (ideal for antigen access and antibody delivery). Furthermore, prostate cancer is also radiation sensitive. Prostate-specific membrane antigen is expressed by virtually all prostate cancers, and represents an attractive target for RIT. Antiprostate-specific membrane antigen RIT demonstrates......Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an important role in the clinical management of patients with prostate cancer. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis...... of anatomic, functional, and molecular imaging information. Positron emission tomography (PET)/computed tomography (CT) in oncology is emerging as an important imaging tool. The most common radiotracer for PET/CT in oncology, (18)F-fluorodeoxyglucose (FDG), is not very useful in the imaging of prostate cancer...

Pulmonary Masses: Initial Results of Cone-beam CT Guidance with Needle Planning Software for Percutaneous Lung Biopsy

Energy Technology Data Exchange (ETDEWEB)

Braak, Sicco J., E-mail: sjbraak@gmail.com [St. Antonius Hospital, Department of Radiology (Netherlands); Herder, Gerarda J. M., E-mail: j.herder@antoniusziekenhuis.nl [St. Antonius Hospital, Department of Pulmonology (Netherlands); Heesewijk, Johannes P. M. van, E-mail: j.heesewijk@antoniusziekenhuis.nl; Strijen, Marco J. L. van, E-mail: m.van.strijen@antoniusziekenhuis.nl [St. Antonius Hospital, Department of Radiology (Netherlands)

2012-12-15

Purpose: To evaluate the outcome of percutaneous lung biopsy (PLB) findings using cone-beam computed tomographic (CT) guidance (CBCT guidance) and compared to conventional biopsy guidance techniques. Methods: CBCT guidance is a stereotactic technique for needle interventions, combining 3D soft-tissue cone-beam CT, needle planning software, and real-time fluoroscopy. Between March 2007 and August 2010, we performed 84 Tru-Cut PLBs, where bronchoscopy did not provide histopathologic diagnosis. Mean patient age was 64.6 (range 24-85) years; 57 patients were men, and 25 were women. Records were prospectively collected for calculating sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. We also registered fluoroscopy time, room time, interventional time, dose-area product (DAP), and complications. Procedures were divided into subgroups (e.g., location, size, operator). Results: Mean lesion diameter was 32.5 (range 3.0-93.0) mm, and the mean number of samples per biopsy procedure was 3.2 (range 1-7). Mean fluoroscopy time was 161 (range 104-551) s, room time was 34 (range 15-79) min, mean DAP value was 25.9 (range 3.9-80.5) Gy{center_dot}cm{sup -2}, and interventional time was 18 (range 5-65) min. Of 84 lesions, 70 were malignant (83.3%) and 14 were benign (16.7%). Seven (8.3%) of the biopsy samples were nondiagnostic. All nondiagnostic biopsied lesions proved to be malignant during surgical resection. The outcome for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 90% (95% confidence interval [CI] 86-96), 100% (95% CI 82-100), 100% (95% CI 96-100), 66.7% (95% CI 55-83), and 91.7% (95% CI 86-96), respectively. Sixteen patients (19%) had minor and 2 (2.4%) had major complications. Conclusion: CBCT guidance is an effective method for PLB, with results comparable to CT/CT fluoroscopy guidance.

Papel da fibrobroncoscopia no diagnóstico de pacientes com suspeita de tuberculose pulmonar Role of the fiberoptic bronchoscopy in the diagnosis of patients with suspected pulmonary

Directory of Open Access Journals (Sweden)

Anna Luiza Summers Caymmi

2004-02-01

que representam diagnósticos diferenciais.BACKGROUND: Pulmonary tuberculosis is an infectious disease of high prevalence and incidence. The use of sputum bacilloscopy is a sure and speedy way of reaching a diagnosis. However as 30% to 50% of the bearers of pulmonary tuberculosis have a negative sputum smear or have no sputum the fiber bronchoscopy acquires a special importance. OBJECTIVES: To evaluate the sensitivity of the specimens collected by means of the fiber bronchoscopy (brochoalveolar lavage and transbronchial biopsy for the diagnosis of patients suspected of having pulmonary tuberculosis, without confirmation by sputum bacilloscopy. METHOD: By review of the ledgers of fiber bronchoscopies carried out from March 1997 to March 2001, we identified and included in the study patients over 18 years of age and referred with suspicion of tuberculosis and at least three negative sputum smears. Data regarding age, gender, changes detected at thorax imaging and endoscopy were collected. RESULTS: Fifty-two patients with ages ranging from 19 to 77 years (median of 39, were included, 58% were of the male gender and 37% were patients from the Official Health System. Prevailing finding at chest X-ray was the alveolar infiltrate (80%. In 35 patients tuberculosis was the final diagnosis (one with associated neoplasia; in 28 patients (80% diagnosis was achieved by bronchoscopy. Other diagnoses disclosed by bronchoscopy were neoplasias, histoplasmosis chronic eosinophil alvelolitis, pneumonia by Pneumocystis carinii and pulmonary fibrosis. CONCLUSION: results of this study point to the use of fiber bronchoscopy in patients suspect of tuberculosis, not diagnosed thorough sputum bacilloscopy, not only for pulmonary tuberculosis but also of those that represent differential diagnoses.

Broncoscopia flexível como primeira opção para a remoção de corpo estranho das vias aéreas em adultos Flexible bronchoscopy as the first-choice method of removing foreign bodies from the airways of adults

Directory of Open Access Journals (Sweden)

Ascedio José Rodrigues

2012-06-01

Full Text Available OBJETIVO: Determinar a taxa de sucesso da broncoscopia flexível como primeira opção na remoção de corpos estranhos das vias aéreas em adultos. MÉTODOS: Estudo retrospectivo de todos os pacientes adultos (acima de 18 anos com aspiração de corpo estranho submetidos a broncoscopia no Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, em São Paulo (SP. RESULTADOS: A amostra foi constituída por 40 pacientes adultos, com média de idade de 52 anos (variação: 18-88 anos. A mediana do tempo de permanência do corpo estranho na via aérea foi de 15 dias (variação: 12 h a 10 anos. Todos os pacientes foram submetidos primeiramente a broncoscopia flexível diagnóstica. A retirada do corpo estranho por meio de broncoscopia flexível foi bem-sucedida em 33 dos pacientes (82,5%. Em 1 paciente, um objeto metálico alojado na árvore brônquica distal requereu o uso de fluoroscopia. Seis pacientes (15% foram submetidos a broncoscopia rígida devido a dispneia induzida por corpo estranho traqueal, em 2, e porque o corpo estranho era muito grande para as pinças flexíveis, em 4. A broncoscopia falhou em apenas 1 paciente, que portanto necessitou de broncotomia. CONCLUSÕES: Embora a broncoscopia rígida seja considerada o padrão ouro na remoção de corpos estranhos na via aérea, nossa experiência mostrou que a broncoscopia flexível pode ser utilizada segura e eficientemente no diagnóstico e tratamento de pacientes adultos estáveis.OBJECTIVE: To determine the success rate of flexible bronchoscopy as the first-choice method of removing foreign bodies from the airways of adults. METHODS: This was a retrospective study of all adult patients (over 18 years of age with foreign body aspiration submitted to bronchoscopy between January of 2009 and January of 2011 at the University of São Paulo School of Medicine Hospital das Clínicas, located in São Paulo, Brazil. RESULTS: The study sample comprised 40 adult patients

Clinical applications of virtual navigation bronchial intervention.

Science.gov (United States)

Kajiwara, Naohiro; Maehara, Sachio; Maeda, Junichi; Hagiwara, Masaru; Okano, Tetsuya; Kakihana, Masatoshi; Ohira, Tatsuo; Kawate, Norihiko; Ikeda, Norihiko

2018-01-01

In patients with bronchial tumors, we frequently consider endoscopic treatment as the first treatment of choice. All computed tomography (CT) must satisfy several conditions necessary to analyze images by Synapse Vincent. To select safer and more precise approaches for patients with bronchial tumors, we determined the indications and efficacy of virtual navigation intervention for the treatment of bronchial tumors. We examined the efficacy of virtual navigation bronchial intervention for the treatment of bronchial tumors located at a variety of sites in the tracheobronchial tree using a high-speed 3-dimensional (3D) image analysis system, Synapse Vincent. Constructed images can be utilized to decide on the simulation and interventional strategy as well as for navigation during interventional manipulation in two cases. Synapse Vincent was used to determine the optimal planning of virtual navigation bronchial intervention. Moreover, this system can detect tumor location and alsodepict surrounding tissues, quickly, accurately, and safely. The feasibility and safety of Synapse Vincent in performing useful preoperative simulation and navigation of surgical procedures can lead to safer, more precise, and less invasion for the patient, and makes it easy to construct an image, depending on the purpose, in 5-10 minutes using Synapse Vincent. Moreover, if the lesion is in the parenchyma or sub-bronchial lumen, it helps to perform simulation with virtual skeletal subtraction to estimate potential lesion movement. By using virtual navigation system for simulation, bronchial intervention was performed with no complications safely and precisely. Preoperative simulation using virtual navigation bronchial intervention reduces the surgeon's stress levels, particularly when highly skilled techniques are needed to operate on lesions. This task, including both preoperative simulation and intraoperative navigation, leads to greater safety and precision. These technological instruments

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 phenomena....... This experimental course provided insights into the challenges involved in virtual processes, and those experiences where used for addressing the challenges that virtual leadership is confronted with. Emphasis was placed on the reduction of undesired virtual distance and its consequences through affinity building....... We found that student scepticism appeared when a breakdown resulted in increasing virtual distance, and raises questions on how leaders might translate or upgrade their understandings of leadership to handling such increased distance through affinity building....

Latest techniques in head and neck CT angiography

International Nuclear Information System (INIS)

Schuknecht, B.

2004-01-01

Continuous evolution of multi row CT is increasingly making CT angiography a viable imaging modality for assessment of the supraaortic and intracranial vessels as an anatomically and functionally coherent vascular system. Extended non-invasive examinations with reduced contrast volume have become feasible with the availability of 16 and 64 row MDCT scanners. Prerequisites to obtain high resolution CT angiographies of the head and neck vessels with superior detail include the administration of low contrast volume, high contrast density (400 mg I/ml) contrast media, adequate timing and data acquisition, optimal flow rate (4 ml/s) and saline flushing. Non-invasiveness, delineation of vessel calcification, virtual independence from hemodynamic conditions, and the ability to provide quantification without needing to correct for magnification are all attributes that favour CT angiography over digital subtraction angiography and to some extent even magnetic resonance angiography as an alternative non-invasive technique. CT angiography is established as a modality of choice for the assessment of patients with acute stroke and chronic steno-occlusive disease. CT angiography may indicate the presence of extra- or intracranial acute vessel occlusion and dissection, predisposing atherosclerotic steno-occlusive disease and thus indicate thrombo-embolism or local appositional thrombosis as the principle pathogenic factor. CT angiography is used to assess anatomy, and to depict the presence, location and extent of calcified and non-calcified plaque as a cause of high grade stenosis. Despite relatively limited sensitivity CT angiography is indicated for suspected or confirmed aneurysms that demand further verification of their presence, geometry, or relationship to parent artery branches and osseous anatomic landmarks. Low volume high density contrast media have substantially increased the ability of CT angiography to depict small aneurysms, small branches, and collateral vessels

The utility of the fiberoptic bronchoscopy in the esophageal cancer

International Nuclear Information System (INIS)

Reyes O, Leonardo; Garcia-Herreros, Plutarco; Rivas P, Pilar; Posso, Hector; Sandoval Rafael L

1998-01-01

The paper establishes the utility of the fiber- optic bronchoscopy (FOB) studies performed in patients with esophageal cancer (EC) and confirm the possibility of tracheo-bronchial compromise. We carry out a descriptive study in 226 patients with esophageal cancer during 1991 to 1996 in the Instituto Nacional de Cancerologia of Colombia (INC). We excluded the patients with previous treatments: radiotherapy or surgery, and others primary cancers with metastases on the esophagus. We analyzed gastric, intestinal and general symptoms, smoking habits, primary cancer location, histological types, radiologic findings, fob findings, micro and macroscopes, and results of the samples: transbronchial, endobronchial biopsies, bronchi alveolar lavage and brush. We included 158 patients, 110 male and 48 female, with age between 32 and 83 years, symptoms duration average of 5,2 months. The most significant were cough, dysphonia and sputum. The location of EC was statistics significance only in the upper third escamocelular type. The significant radiological findings were: parenchymal nodules and interstitial infiltrates, the significant fob findings were: fistula endobronchial infiltration endobronchial mass and vocal cords palsy. The zones with more compromise were trachea, principal bronchi and vocal cords. Only 17 patients were positives in the samples; comparing the histopathologic findings (biopsies) as the gold standard with fob findings the sensitivity was 100%, specificity 35%, positive predictive value 15.6% and negative predictive value 100%

An evaluation on CT image acquisition method for medical VR applications

Science.gov (United States)

Jang, Seong-wook; Ko, Junho; Yoo, Yon-sik; Kim, Yoonsang

2017-02-01

Recent medical virtual reality (VR) applications to minimize re-operations are being studied for improvements in surgical efficiency and reduction of operation error. The CT image acquisition method considering three-dimensional (3D) modeling for medical VR applications is important, because the realistic model is required for the actual human organ. However, the research for medical VR applications has focused on 3D modeling techniques and utilized 3D models. In addition, research on a CT image acquisition method considering 3D modeling has never been reported. The conventional CT image acquisition method involves scanning a limited area of the lesion for the diagnosis of doctors once or twice. However, the medical VR application is required to acquire the CT image considering patients' various postures and a wider area than the lesion. A wider area than the lesion is required because of the necessary process of comparing bilateral sides for dyskinesia diagnosis of the shoulder, pelvis, and leg. Moreover, patients' various postures are required due to the different effects on the musculoskeletal system. Therefore, in this paper, we perform a comparative experiment on the acquired CT images considering image area (unilateral/bilateral) and patients' postures (neutral/abducted). CT images are acquired from 10 patients for the experiments, and the acquired CT images are evaluated based on the length per pixel and the morphological deviation. Finally, by comparing the experiment results, we evaluate the CT image acquisition method for medical VR applications.

The Delivery of Business Courses via the African Virtual University: A Case Study

Science.gov (United States)

Graber, Mark; Bolt, Susan

2011-01-01

In this case study the delivery of business courses as a result of the partnership between the African Virtual University (AVU) and Curtin University in Western Australia is described. From 2004 to 2008, degree and diploma business courses were delivered using WebCT in the four AVU partner locations: Addis Ababa University (Ethiopia), Kigali…

Virtual stress testing of fracture stability in soldiers with severely comminuted tibial fractures.

Science.gov (United States)

Petfield, Joseph L; Hayeck, Garry T; Kopperdahl, David L; Nesti, Leon J; Keaveny, Tony M; Hsu, Joseph R

2017-04-01

Virtual stress testing (VST) provides a non-invasive estimate of the strength of a healing bone through a biomechanical analysis of a patient's computed tomography (CT) scan. We asked whether VST could improve management of patients who had a tibia fracture treated with external fixation. In a retrospective case-control study of 65 soldier-patients who had tibia fractures treated with an external fixator, we performed VST utilizing CT scans acquired prior to fixator removal. The strength of the healing bone and the amount of tissue damage after application of an overload were computed for various virtual loading cases. Logistic regression identified computed outcomes with the strongest association to clinical events related to nonunion within 2 months after fixator removal. Clinical events (n = 9) were associated with a low tibial strength for compression loading (p fracture patients who can safely resume weight bearing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:805-811, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

The relationship between image quality and CT dose index of multi-slice low-dose chest CT

International Nuclear Information System (INIS)

Zhu Xiaohua; Shao Jiang; Shi Jingyun; You Zhengqian; Li Shijun; Xue Yongming

2003-01-01

Objective: To explore the rationality and possibility of multi-slice low-dose CT scan in the examination of the chest. Methods: (1) X-ray dose index measurement: 120 kV tube voltage, 0.75 s rotation, 8 mm and 3 mm slice thickness, and the tube current setting of 115.0, 40.0, 25.0, and 7.5 mAs were employed in every section. The X-ray radiation dose was measured and compared statistically. (2) phantom measurement of homogeneity and noise: The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm sections, and every slice was scanned using tube current of 115.0, 40.0, 25.0, and 7.5 mAs. Five same regions of interest were measured on every image. The homogeneity and noise level of CT were appraised. (3) The multi-slice low-dose CT in patients: 30 patients with mass and 30 with patch shadow in the lung were selected randomly. The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm slice thickness. 115.0, 40.0, 25.0, 15.0, and 7.5 mAs tube current were employed in each same slice. Otherwise, 15 cases with helical scan were examined using 190, 150, 40, 25, and 15 mAs tube current. The reconstruction images of MIP, MPR, CVR, HRCT, 3D, CT virtual endoscopy, and variety of interval reconstruction were compared. (4) Evaluation of image quality: CT images were evaluated by four doctors using single-blind method, and 3 degrees including normal image, image with few artifact, and image with excessive artifact, were employed and analyzed statistically. Results: (1) The CT dose index with 115.0 mAs tube current exceeded those of 40.0, 25.0, and 7.5 mAs by about 60%, 70%, and 85%, respectively. (2) The phantom measurement showed that the lower of CT dose the lower of homogeneity, the lower of CT dose the higher of noise level. (3) Result of image quality evaluation: The percentage of the normal image had no significant difference between 8 and 3 mm in 115, 40, and 25 mAs (P>0.05). Conclusion: Multi-slice low-dose chest CT technology may protect the patients and guarantee the

Detection of unknown primary neuroendocrine tumours (CUP-NET) using {sup 68}Ga-DOTA-NOC receptor PET/CT

Energy Technology Data Exchange (ETDEWEB)

Prasad, Vikas; Baum, Richard P. [Zentralklinik Bad Berka, Department of Nuclear Medicine and Centre for PET/CT, Bad Berka (Germany); Ambrosini, Valentina; Fanti, Stefano [University of Bologna, Nuclear Medicine Unit, Policlinico S. Orsola-Malpighi, Bologna (Italy); Hommann, Merten [Zentralklinik Bad Berka, Department of General and Visceral Surgery, Bad Berka (Germany); Hoersch, Dieter [Zentralklinik Bad Berka, Department of Internal Medicine/Gastroenterology, Oncology and Endocrinology, Bad Berka (Germany)

2010-01-15

This bi-centric study aimed to determine the role of receptor PET/CT using {sup 68}Ga-DOTA-NOC in the detection of undiagnosed primary sites of neuroendocrine tumours (NETs) and to understand the molecular behaviour of the primarily undiagnosed tumours. Overall 59 patients (33 men and 26 women, age: 65 {+-} 9 years) with documented NET and unknown primary were enrolled. PET/CT was performed after injection of approximately 100 MBq (46-260 MBq) of {sup 68}Ga-DOTA-NOC. The maximum standardised uptake values (SUV{sub max}) were calculated and compared with SUV{sub max} in known pancreatic NET (pNET) and ileum/jejunum/duodenum (SI-NET). The results of PET/CT were also correlated with CT alone. In 35 of 59 patients (59%), {sup 68}Ga-DOTA-NOC PET/CT localised the site of the primary: ileum/jejunum (14), pancreas (16), rectum/colon (2), lungs (2) and paraganglioma (1). CT alone (on retrospective analyses) confirmed the findings in 12 of 59 patients (20%). The mean SUV{sub max} of identified previously unknown pNET and SI-NET were 18.6 {+-} 9.8 (range: 7.8-34.8) and 9.1 {+-} 6.0 (range: 4.2-27.8), respectively. SUV{sub max} in patients with previously known pNET and SI-NET were 26.1 {+-} 14.5 (range: 8.7-42.4) and 11.3 {+-} 3.7 (range: 5.6-17.9). The SUV{sub max} of the unknown pNET and SI-NET were significantly lower (p < 0.05) as compared to the ones with known primary tumour sites; 19% of the patients had high-grade and 81% low-grade NET. Based on {sup 68}Ga-DOTA-NOC receptor PET/CT, 6 of 59 patients were operated and the primary was removed (4 pancreatic, 1 ileal and 1 rectal tumour) resulting in a management change in approximately 10% of the patients. In the remaining 29 patients, because of the far advanced stage of the disease (due to distant metastases), the primary tumours were not operated. Additional histopathological sampling was available from one patient with bronchial carcinoid (through bronchoscopy). Our data indicate that {sup 68}Ga-DOTA-NOC PET/CT is

Virtual reality exposure versus cognitive restructuring for treatment of public speaking anxiety: a pilot study.

Science.gov (United States)

Wallach, Helene S; Safir, Marilyn P; Bar-Zvi, Margalit

2011-01-01

To determine the utility of Virtual Reality Exposure Therapy (VRE) in comparison with Cognitive Therapy (CT ) and with Cognitive-Behavior Therapy (CBT). Subjects suffering from public speaking anxiety (PSA) were randomly allocated to VRE and CT , and received 12 therapy sessions, employing standardized treatment manuals. Outcome (questionnaires, observer and self ratings of a behavioral task) was compared to results of subjects in a previous study CBT and Wait List Controls who were not significantly different on demographic data. CT was not superior to VRE on cognitive measures, but was superior to VRE on one behavioral measure (LSAS fear). VRE was superior to CT on one behavioral measure (fear reduction on a behavioral task). No differences were found between either CT , or VRE, and CBT and all were superior to WL. Subject group was small and homogeneous. It appeared advisable to increase number of therapy sessions. VRE and CT proved to be equally effective to CBT in reducing PSA relative to a control group, with minimal differential effects between them. Therefore, employing either one may be satisfactory and sufficient.

Virtual goods recommendations in virtual worlds.

Science.gov (United States)

Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

2015-01-01

Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

Stereoscopic virtual reality models for planning tumor resection in the sellar region

Directory of Open Access Journals (Sweden)

Wang Shou-sen

2012-11-01

Full Text Available Abstract Background It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region. Methods To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery. Results All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images. Conclusions The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.

Present status and future view on virtual endoscopy. Depiction of minute lesions in the large intestine with CT colonography

International Nuclear Information System (INIS)

Sugino, Yoshinori

2002-01-01

CT colonography is a new imaging technique using helical CT. We studied the efficacy of CT colonoscopy in the detection of small polyps and depiction of superficial lesions. Concerning the detection of small polyps, we studied 54 patients with abnormality checked by barium enema. Conventional colonoscopy revealed 79 lesions (5 advanced carcinomas, 4 superficial-type adenomas and 70 polyps). CT colonography identified all 5 carcinomas, 3 of the 4 superficial lesions and 43 of the 45 polyps that were 0.5 cm or smaller in diameter, 18 of 22 polyps that were 0.6 to 0.9 cm, and all 3 polyps that were 1.0 cm or more in diameter. There were 92 false positive polyps that were 0.5 cm or smaller in diameter. On a superficial lesion, we could depict a superficial depressive type early colonic carcinoma 1.0 cm in diameter, using very thin-slice CT equipment. In conclusion, CT colonography has a high sensitivity for detection of small polyps and sufficient capability for depiction of superficial lesions. CT colonography may be suitable for screening examinations of the large intestine. (author)

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.)

Two-pass dual-energy CT imaging for simultaneous detection, characterization, and volume measurement of urinary stones with excretory-phase CT urography alone. A phantom study

International Nuclear Information System (INIS)

Takahashi, Satoru; Niikawa, Hidekazu; Shikata, Atsushi; Murakami, Emi; Tsunoda, Hiroshi; Yoshioka, Toshiaki; Yamamoto, Hiroshi; Itoh, Toshihide; Tsujihata, Masao

2013-01-01

The purpose of this study was to evaluate if two-pass dual-energy CT imaging - id est (i.e.), simultaneous three-material and two-material decomposition analysis - can depict and characterize urinary stones in various concentrations of iodine solution in vitro. Twelve urinary stones were scanned with a dual-source CT scanner. First, each stone (in a saline-filled tube) underwent single- and dual-energy mode CT scans in order to measure the volume of the stone. Each stone was then placed in various concentrations of contrast medium and scanned in dual-energy mode to calculate its volume via three-material decomposition analysis. Two-pass dual-energy CT imaging analysis software for the Matlab environment, which was developed specifically to process simultaneous three-material and two-material decomposition, was applied to characterize and calculate the volume of each stone. Although the virtual non-contrast images from three-material decomposition analysis clearly visualized all of the stones in contrast medium with up to 80 mgI/mL, the volumes of the uric acid stones were overestimated. Two-pass dual-energy CT imaging was able to depict and characterize non-uric-acid stones in diluted contrast medium with up to 80 mgI/mL, whereas uric acid stones were correctly evaluated in diluted contrast medium with 40 mgI/mL or less. Two-pass dual-energy CT imaging is able to depict and characterize urinary stones in contrast medium. (author)

Virtual marketing in virtual enterprises

OpenAIRE

Ale Ebrahim, Nader; Fattahi, Hamaid Ali; Golnam, Arash

2008-01-01

Virtualization caused tremendous evolution in the economics of marketing channels, patterns of physical distribution and the structure of distributors and developed a new concept that is known as virtual marketing (VM). VM combines the powerful technologies of interactive marketing and virtual reality. Virtual enterprise (VE) refers to an organization not having a clear physical locus. In other words, VE is an organization distributed geographically and whose work is coordinated through e...

Pulmonary actinomycosis

Science.gov (United States)

The health care provider will perform a physical exam, and ask about your medical history and symptoms. Tests that may be done include: Bronchoscopy with culture Complete blood count (CBC) Chest x-ray Chest CT scan Lung biopsy Modified AFB smear of sputum ...

Ultra-low-dose CT imaging of the thorax: decreasing the radiation dose by one order of magnitude

International Nuclear Information System (INIS)

Lambert, Lukas; Banerjee, Rohan; Votruba, Jiri; El-Lababidi, Nabil; Zeman, Jiri

2016-01-01

Computed tomography (CT) is an indispensable tool for imaging of the thorax and there is virtually no alternative without associated radiation burden. The authors demonstrate ultra-low-dose CT of the thorax in three interesting cases. In an 18-y-old girl with rheumatoid arthritis, CT of the thorax identified alveolitis in the posterior costophrenic angles (radiation dose = 0.2 mSv). Its resolution was demonstrated on a follow-up scan (4.2 mSv) performed elsewhere. In an 11-y-old girl, CT (0.1 mSv) showed changes of the right collar bone consistent with chronic recurrent multifocal osteomyelitis. CT (0.1 mSv) of a 9-y-old girl with mucopolysaccharidosis revealed altogether three hamartomas, peribronchial infiltrate, and spine deformity. In some indications, the radiation dose from CT of the thorax can approach that of several plain radiographs. This may help the pediatrician in deciding whether 'gentle' ultra-low-dose CT instead of observation or follow-up radiographs will alleviate the uncertainty of the diagnosis with little harm to the child. (author)

Virtual Presenters: Towards Interactive Virtual Presentations

NARCIS (Netherlands)

Nijholt, Antinus; Cappellini, V.; Hemsley, J.

2005-01-01

We discuss having virtual presenters in virtual environments that present information to visitors of these environments. Some current research is surveyed and we will look in particular to our research in the context of a virtual meeting room where a virtual presenter uses speech, gestures, pointing

Single- and dual-energy quantitative CT adjacent to acetabular prosthetic components

DEFF Research Database (Denmark)

Mussmann, Bo Redder; Andersen, Poul Erik; Torfing, Trine

2017-01-01

and to compare BMD measurements in single and dual energy CT (SECT and DECT). Methods and Materials: 10 male patients with uncemented hip prosthetics were scanned and rescanned using 120 kVp SECT and DECT with virtual monochromatic images reconstructed at 130 keV. Hemispherical ROIs were defined slice...... that the intraobserver agreement of the scan modes is equal. BMD cannot be measured interchangeably with SECT and DECT....

Hyalinizing Granuloma: An Unusual Case of a Pulmonary Mass

Directory of Open Access Journals (Sweden)

Viviane Brandão

2010-01-01

Full Text Available We describe the case of pulmonary hyalinizing granuloma in a 34-year-old asymptomatic man who presented with a pulmonary nodule apparent by chest radiography and computed tomography (CT. He had a history of previous treatment for tuberculosis. His laboratory data were normal. Bronchoscopy and CT-guided percutaneous transthoracic fine needle aspiration cytology were inconclusive. The diagnosis was revealed after the histopathological examination of an open lung biopsy.

Virtual Worlds for Virtual Organizing

Science.gov (United States)

Rhoten, Diana; Lutters, Wayne

The members and resources of a virtual organization are dispersed across time and space, yet they function as a coherent entity through the use of technologies, networks, and alliances. As virtual organizations proliferate and become increasingly important in society, many may exploit the technical architecture s of virtual worlds, which are the confluence of computer-mediated communication, telepresence, and virtual reality originally created for gaming. A brief socio-technical history describes their early origins and the waves of progress followed by stasis that brought us to the current period of renewed enthusiasm. Examination of contemporary examples demonstrates how three genres of virtual worlds have enabled new arenas for virtual organizing: developer-defined closed worlds, user-modifiable quasi-open worlds, and user-generated open worlds. Among expected future trends are an increase in collaboration born virtually rather than imported from existing organizations, a tension between high-fidelity recreations of the physical world and hyper-stylized imaginations of fantasy worlds, and the growth of specialized worlds optimized for particular sectors, companies, or cultures.

X-ray phase-contrast CT of a pancreatic ductal adenocarcinoma mouse model.

Directory of Open Access Journals (Sweden)

Arne Tapfer

Full Text Available To explore the potential of grating-based x-ray phase-contrast computed tomography (CT for preclinical research, a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC was investigated. One ex-vivo mouse specimen was scanned with different grating-based phase-contrast CT imaging setups covering two different settings: i high-resolution synchrotron radiation (SR imaging and ii dose-reduced imaging using either synchrotron radiation or a conventional x-ray tube source. These experimental settings were chosen to assess the potential of phase-contrast imaging for two different types of application: i high-performance imaging for virtual microscopy applications and ii biomedical imaging with increased soft-tissue contrast for in-vivo applications. For validation and as a reference, histological slicing and magnetic resonance imaging (MRI were performed on the same mouse specimen. For each x-ray imaging setup, attenuation and phase-contrast images were compared visually with regard to contrast in general, and specifically concerning the recognizability of lesions and cancerous tissue. To quantitatively assess contrast, the contrast-to-noise ratios (CNR of selected regions of interest (ROI in the attenuation images and the phase images were analyzed and compared. It was found that both for virtual microscopy and for in-vivo applications, there is great potential for phase-contrast imaging: in the SR-based benchmarking data, fine details about tissue composition are accessible in the phase images and the visibility of solid tumor tissue under dose-reduced conditions is markedly superior in the phase images. The present study hence demonstrates improved diagnostic value with phase-contrast CT in a mouse model of a complex endogenous cancer, promoting the use and further development of grating-based phase-contrast CT for biomedical imaging applications.

Inner images of the human body with a 3D CT scanner

International Nuclear Information System (INIS)

Kobayashi, Hisashi

1994-01-01

This article deals with not only CT-endoscopy (CTES) technique but also various imaging and processing techniques of 3D CT. CTES images, which were obtained from 137 patients with suspected cardiovascular disorder or disease of other tubular organs, were reconstructed using a newly developed volumetric scanner with a slip-ring system. Among the 137 patients, 107 (78%) were successfully diagnosed by CTES. For cardiovascular region, dissecting aneurysm was detected in 27/32, aortitis in 9/9, and intra-arterial thrombosis in 5/6. Various imaging and processing techniques, including CT number conversion technique, multi-threshold range imaging, 'open-window' and 'virtual operation', and long segmental arteriogram by intravenous contrast injection, are displayed in futures. In conclusion, CTES might become a safe and minimally invasive means for observing the inner surface of the tubular organs, particularly of the aorta, without the need of fiberscopic manipulation. (N.K.)

Traumatic thoracic injury: the role of Multidetector-row CT

Energy Technology Data Exchange (ETDEWEB)

Park, Kyung Joo; Kang, Doo Kyung; Kim, Tae Hee [Ajou University School of Medicine, Suwon (Korea, Republic of)

2006-05-15

The introduction of Multidetector-row CT (MDCT) has revolutionized the diagnostic strategy of multitrauma patients. The rapid acquisition of a large scanning volume with a thin slice collimation allows for motion-free images of high spatial resolution, and this enables the application of the multiplanar reformat (MPR) and 3D volume-rendering (VR) images. The MPR images more accurately demonstrate aortic rupture or dissection, diaphragmatic injuries and fracture of vertebrae, sternum and costal cartilages. Diagnosing vascular injuries can be aided by using the MIP images. Rib fracture, trachea and bronchial laceration are more easily detected by the 3D images, while airway and vascular injuries can be detected from performing virtual endoscopy. We introduce our current CT imaging protocol and we present our clinical experience with using MDCT in the assessment of patients with blunt thoracic trauma.

Bronchoscopic guidance of endovascular stenting limits airway compression.

Science.gov (United States)

Ebrahim, Mohammad; Hagood, James; Moore, John; El-Said, Howaida

2015-04-01

Bronchial compression as a result of pulmonary artery and aortic arch stenting may cause significant respiratory distress. We set out to limit airway narrowing by endovascular stenting, by using simultaneous flexible bronchoscopy and graduated balloon stent dilatation, or balloon angioplasty to determine maximum safe stent diameter. Between August 2010 and August 2013, patients with suspected airway compression by adjacent vascular structures, underwent CT or a 3D rotational angiogram to evaluate the relationship between the airway and the blood vessels. If these studies showed close proximity of the stenosed vessel and the airway, simultaneous bronchoscopy and graduated stent re-dilation or graduated balloon angioplasty were performed. Five simultaneous bronchoscopy and interventional catheterization procedures were performed in four patients. Median age/weight was 33 (range 9-49) months and 14 (range 7.6-24) kg, respectively. Three had hypoplastic left heart syndrome, and one had coarctation of the aorta (CoA). All had confirmed or suspected left main stem bronchial compression. In three procedures, serial balloon dilatation of a previously placed stent in the CoA was performed and bronchoscopy was used to determine the safest largest diameter. In the other two procedures, balloon testing with simultaneous bronchoscopy was performed to determine the stent size that would limit compression of the adjacent airway. In all cases, simultaneous bronchoscopy allowed selection of an ideal caliber of the stent that optimized vessel diameter while minimizing compression of the adjacent airway. In cases at risk for airway compromise, flexible bronchoscopy is a useful tool to guide endovascular stenting. Maximum safe stent diameter can be determined without risking catastrophic airway compression. © 2014 Wiley Periodicals, Inc.

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner

Energy Technology Data Exchange (ETDEWEB)

Diekhoff, T., E-mail: torsten.diekhoff@charite.de [Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin (Germany); Hermann, K.G. [Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin (Germany); Pumberger, M. [Department of Spine Surgery, Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin Campus Mitte, Berlin (Germany); Hamm, B. [Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin (Germany); Putzier, M.; Fuchs, M. [Department of Spine Surgery, Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin Campus Mitte, Berlin (Germany)

2017-02-15

Objectives: Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference. Materials and methods: Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5 T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen’s kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results: Fourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75–1.0 among all readers) and specificity of 1.0 (0.81–1.0). Interrater agreement was inferior for DECT (κ = 0.63–0.89) compared to MRI (κ = 0.9–1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r = 0.87) and inversely with T1 (-0.89). SNR (0.2 +/− 0.2 in VNC and 16.7 +/− 7.3 in STIR) and CNR (0.2 +/− 0.3 and 7.1 +/− 6.3) values were inferior in VNC. Conclusions: Detecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner

International Nuclear Information System (INIS)

Diekhoff, T.; Hermann, K.G.; Pumberger, M.; Hamm, B.; Putzier, M.; Fuchs, M.

2017-01-01

Objectives: Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference. Materials and methods: Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5 T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen’s kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results: Fourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75–1.0 among all readers) and specificity of 1.0 (0.81–1.0). Interrater agreement was inferior for DECT (κ = 0.63–0.89) compared to MRI (κ = 0.9–1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r = 0.87) and inversely with T1 (-0.89). SNR (0.2 +/− 0.2 in VNC and 16.7 +/− 7.3 in STIR) and CNR (0.2 +/− 0.3 and 7.1 +/− 6.3) values were inferior in VNC. Conclusions: Detecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner.

Science.gov (United States)

Diekhoff, T; Hermann, K G; Pumberger, M; Hamm, B; Putzier, M; Fuchs, M

2017-02-01

Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference. Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen's kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Fourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75-1.0 among all readers) and specificity of 1.0 (0.81-1.0). Interrater agreement was inferior for DECT (κ=0.63-0.89) compared to MRI (κ=0.9-1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r=0.87) and inversely with T1 (-0.89). SNR (0.2+/- 0.2 in VNC and 16.7+/- 7.3 in STIR) and CNR (0.2+/- 0.3 and 7.1+/- 6.3) values were inferior in VNC. Detecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity. However, image quality of VNC reconstructions has to be improved to achieve better

Virtual CT endoscopy of the tympanic cavity - early observation

International Nuclear Information System (INIS)

Spryszynski, P.

2002-01-01

In recent times the invention of the bionic ear' and other numerous technological advances have seen many patients have their hearing either restored or instated for the first time New challenges and pathologies are being met and overcome all the time One of the challenges has been to verify the structural soundness of the ossicular chain and the structures of the tympanic cavity Congenital deafness can be caused by a congenital malformation of a bone in the ossicular chain or a deformity of any of the ligaments or membranes forming the tympanic cavity. The advent of rapid resolution computerised tomography (CT) scanning has allowed clinicians to view minute structures, otherwise thought impossible to image. This paper discusses a recently developed application and its limitations in the imaging of the structure of the middle ear and the ossicular chain. Copyright (2002) Australian Institute of Radiography

双源CT双能量胸部虚拟平扫的应用价值%Application of dual energy virtual non-contrast CT of dual source CT in thorax

Institute of Scientific and Technical Information of China (English)

江杰; 何波; 张俊; 韩丹

2012-01-01

To investigate the clinical feasibility of dual energy virtual non-contrast CT (VNC) of dual source CT in the thorax in comparison with conventional plain scan. Methods In total of 155 patients suspected with thorax diseases were performed conventional plain scan and dual energy enhanced scan. VNC images were obtained through post-processing. Mean CT values, SNR, image quality, detectability of lesions and radiation dosage were compared between the conventional plain scan and VNC. Results In VNC images, mean CT value in pulmonary artery trunk was higher than conventional plain scan (P0. 05). SNR of VNC was higher than that of conventional plain scan (P0. 05). VNC and conventional plain scan had similar performance for the detection of lesions, except some calcified lesions (6/21) and small lymph nodes (3/37) near the superior vena cava were not identified in VNC, while the other lesions can be shown. The radiation dosage of VNC were slightly higher than conventional plain scan (P<0. 05). Conclusion Dual energy enhanced scan in the thorax could get enhanced images and VNC images in one scan. VNC images could not affect image quality and detectability of lesions, significantly reduce the radiation dosage, which has a potential clinical value in the thorax.%目的 通过对比胸部常规平扫与双源CT双能量虚拟平扫(VNC),探讨VNC临床应用的可行性.方法 对155例怀疑胸部疾病的患者行常规CT平扫和双能CT增强扫描,后处理得到VNC图像,对VNC和常规平扫平均CT值、SNR、图像质量、病灶显示情况、辐射剂量等方面进行比较.结果 肺动脉干处平均CT值VNC高于常规平扫(P＜0.05),而左心室及脊柱后方肌肉处差异均无统计学意义(P均＞0.05). VNC ROI选在肺动脉干、左心室、脊柱后方肌肉的图像SNR均高于常规平扫(P＜0.05). VNC图像质量与常规平扫比较差异无统计学意义(P＞0.05).VNC的病灶显示情况类似,除部分钙化灶(6/21)�

Microwave ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma undetectable by conventional ultrasonography

International Nuclear Information System (INIS)

Liu Fangyi; Yu Xiaoling; Liang Ping; Cheng Zhigang; Han Zhiyu; Dong Baowei; Zhang Xiaohong

2012-01-01

Objectives: To evaluate the efficiency and feasibility of microwave (MW) ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma (HCC) undetectable by conventional ultrasonography. Methods: 18 patients with 18 HCC nodules (undetectable on conventional US but detectable by intravenous contrast-enhanced CT or MRI) were enrolled in this study. Before MW ablation, US images and MRI or CT images were synchronized using the internal markers at the best timing of the inspiration. Thereafter, MW ablation was performed under real-time virtual navigation system guidance. Therapeutic efficacy was assessed by the result of contrast-enhanced imagings after the treatment. Results: The target HCC nodules could be detected with fusion images in all patients. The time required for image fusion was 8–30 min (mean, 13.3 ± 5.7 min). 17 nodules were successfully ablated according to the contrast enhanced imagings 1 month after ablation. The technique effectiveness rate was 94.44% (17/18). The follow-up time was 3–12 months (median, 6 months) in our study. No severe complications occurred. No local recurrence was observed in any patients. Conclusions: MW ablation assisted by a real-time virtual navigation system is a feasible and efficient treatment of patients with HCC undetectable by conventional ultrasonography.

Attenuation values of renal parenchyma in virtual noncontrast images acquired from multiphase renal dual-energy CT: Comparison with standard noncontrast CT.

Science.gov (United States)

Lin, Yuan-Mao; Chiou, Yi-You; Wu, Mei-Han; Huang, Shan-Su; Shen, Shu-Huei

2018-04-01

To compare the renal parenchyma attenuation of virtual noncontrast (VNC) images derived from multiphase renal dual-energy computed tomography (DECT) with standard noncontrast (SNC) images, and to determine the optimum phase for VNC images. Twenty-nine men and 16 women (mean age, 61 ± 13 years; range, 37-89 years) underwent dynamic renal DECT (100/Sn140 kVp) were included in this institutional review board-approved retrospective study. There were four phases of the scan, which included noncontrast, corticomedullary (CMP), nephrographic (NP), and excretory phases (EP). The VNC images was generated from CMP, NP and EP. CT numbers of SNC images and VNC images of each phases were measured in the renal cortex and medulla. Mean standard deviation of subcutaneous fat was measured as image noise on SNC and VNC images. Radiation dose was recorded and potential radiation dose reduction was estimated. Results were tested for statistical significance using the unpaired t-test and agreement using Bland-Altman plot analysis. The difference in mean attenuation between SNC and each phase of VNC images were ≤4 HU. The mean attenuation of renal cortex and medulla was 33.2 ± 4.4 HU, and 34.2 ± 4.8 HU in SNC, 33.6 ± 7.6 HU and 31.1 ± 8.3 HU in VNC of CMP, 34.8 ± 8.6 HU and 35.6 ± 8.5 HU in VNC of NP, 31.5 ± 7.6 HU and 32.4 ± 7.5 HU in VNC of EP. In VNC of CMP, the attenuation of the cortex was higher than the medulla (p VNC of NP, the attenuation of renal cortex was higher than SNC (p VNC of EP, the attenuation of cortex and medulla were lower than SNC (p VNC images from multiphase renal DECT were similar to SNC images. Using the nephrographic phase can gives more comparable VNC images to SNC images in renal parenchyma than other phases. Copyright © 2018 Elsevier B.V. All rights reserved.

Tracheal web

International Nuclear Information System (INIS)

Legasto, A.C.; Haller, J.O.; Giusti, R.J.

2004-01-01

Congenital tracheal web is a rare entity often misdiagnosed as refractory asthma. Clinical suspicion based on patient history, examination, and pulmonary function tests should lead to its consideration. Bronchoscopy combined with CT imaging and multiplanar reconstruction is an accepted, highly sensitive means of diagnosis. (orig.)

The potential of dual-energy virtual monochromatic imaging in reducing renal cyst pseudoenhancement. A phantom study

International Nuclear Information System (INIS)

Yamada, Sachiko; Ueguchi, Takashi; Ukai, Isao; Nagai, Yumiko; Yamakawa, Masanobu; Shimosegawa, Eku; Shimazu, Takeshi; Hatazawa, Jun

2012-01-01

Renal cyst pseudoenhancement, an artifactual increase of computed tomography (CT) attenuation for cysts with increased iodine concentrations in the renal parenchyma, complicates the classification of cysts and may thus lead to the mischaracterization of a benign non-enhancing lesion as an enhancing mass. The purpose of this study was to use a phantom model to assess the ability of dual-energy virtual monochromatic imaging to reduce renal pseudoenhancement. A water-filled cylindrical cyst model suspended in varying concentrations of iodine solution, to simulate varying levels of parenchymal enhancement, was scanned with a dual-energy CT scanner using the following three scanning protocols with different combinations of tube voltage: 80 and 140 kV; 80 and 140 kV with tin filter; and 100 and 140 kV with tin filter. Virtual monochromatic images were then synthesized for each dual-energy scan. Single-energy scan with a tube voltage of 120 kV was also performed to obtain polychromatic images as controls. Mean attenuation values (in Hounsfield units) of cyst proxies were measured on both polychromatic and virtual monochromatic images. Pseudoenhancement was considered to be present when the cyst attenuation level increased by more than 10 HU (Hounsfield Unit) as the background iodine concentration increased from 0.0% to 0.4%, 1.5%, or 2.5%. Our results revealed that pseudoenhancement was not observed on any of the monochromatic images, but appeared on polychromatic images at a background iodine concentration of 2.5%. We thus conclude that dual-energy virtual monochromatic images have a potential to reduce renal pseudoenhancement. (author)

Virtual cystoscopy, computed tomography urography and optical cystoscopy for the detection and follow-up for bladder cancer.

Science.gov (United States)

Ibáñez Muñoz, D; Quintana Martínez, I; Fernández Militino, A; Sánchez Zalabardo, D; Sarria Octavio de Toledo, L; Cozcolluela Cabrejas, R

To evaluate the utility of virtual cystoscopy (VC) performed with CT urography in patients being studied under gross hematuria or patients being followed-up after a previous bladder cancer and compare the results with those obtained with gold standard technique (optical cystoscopy). Retrospective study of 117 patients who were referred for VC by the Urology Department between May 2014 and May 2015. Those patients presented with gross hematuria or they were previously treated patients from bladder cancer being followed up. These patients were evaluated with MDCT and virtual cystoscopy after distending the bladder with air. The results were compared with those obtained with optical cystoscopy which was performed no more than a week after. The global sensitivity and specificity of VC were 81,8 and 92,1%. Aditional findings detected in CT urography were an aortic dissection, urinary lithiasis and colonic metastasis. VC seems an useful technique in the diagnosis and follow-up for bladder cancer with a good correlation with OC. The main limitations are the impossibility of biopsy during the procedure and the detection of erythematous lesions. Collateral findings can be detected performed with CT urography although the high radiation exposure does not recommend their combined use. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Sensorial Virtualization: Coupling Gaming and Virtual Environment

NARCIS (Netherlands)

Garbaya, S.; Miraoui, C.; Wendrich, Robert 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

MDCT assessment of tracheomalacia in symptomatic infants with mediastinal aortic vascular anomalies: preliminary technical experience

International Nuclear Information System (INIS)

Lee, Edward Y.; Mason, Keira P.; Zurakowski, David; Waltz, David A.; Ralph, Amy; Riaz, Farhana; Boiselle, Phillip M.

2008-01-01

Mediastinal aortic vascular anomalies are relatively common causes of extrinsic central airway narrowing in infants with respiratory symptoms. Surgical correction of mediastinal aortic vascular anomalies alone might not adequately treat airway symptoms if extrinsic narrowing is accompanied by intrinsic tracheomalacia (TM), a condition that escapes detection on routine end-inspiratory imaging. Paired inspiratory-expiratory multidetector CT (MDCT) has the potential to facilitate early diagnosis and timely management of TM in symptomatic infants with mediastinal aortic vascular anomalies. To assess the technical feasibility of paired inspiratory-expiratory MDCT for evaluating TM among symptomatic infants with mediastinal aortic vascular anomalies. The study group consisted of five consecutive symptomatic infants (four male, one female; mean age 4.1 months, age range 2 weeks to 6 months) with mediastinal aortic vascular anomalies who were referred for paired inspiratory-expiratory MDCT during a 22-month period. CT angiography was concurrently performed during the end-inspiration phase of the study. Two pediatric radiologists in consensus reviewed all CT images in a randomized and blinded fashion. The end-inspiration and end-expiration CT images were reviewed for the presence and severity of tracheal narrowing. TM was defined as ≥50% reduction in tracheal cross-sectional luminal area between end-inspiration and end-expiration. The presence of TM was compared to the bronchoscopy results when available (n = 4). Paired inspiratory-expiratory MDCT was technically successful in all five patients. Mediastinal aortic vascular anomalies included a right aortic arch with an aberrant left subclavian artery (n = 2), innominate artery compression (n = 2), and a left aortic arch with an aberrant right subclavian artery (n 1). Three (60%) of the five patients demonstrated focal TM at the level of mediastinal aortic vascular anomalies. The CT results were concordant with the results

Pulmonary Masses: Initial Results of Cone-beam CT Guidance with Needle Planning Software for Percutaneous Lung Biopsy

International Nuclear Information System (INIS)

Braak, Sicco J.; Herder, Gerarda J. M.; Heesewijk, Johannes P. M. van; Strijen, Marco J. L. van

2012-01-01

Purpose: To evaluate the outcome of percutaneous lung biopsy (PLB) findings using cone-beam computed tomographic (CT) guidance (CBCT guidance) and compared to conventional biopsy guidance techniques. Methods: CBCT guidance is a stereotactic technique for needle interventions, combining 3D soft-tissue cone-beam CT, needle planning software, and real-time fluoroscopy. Between March 2007 and August 2010, we performed 84 Tru-Cut PLBs, where bronchoscopy did not provide histopathologic diagnosis. Mean patient age was 64.6 (range 24–85) years; 57 patients were men, and 25 were women. Records were prospectively collected for calculating sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. We also registered fluoroscopy time, room time, interventional time, dose–area product (DAP), and complications. Procedures were divided into subgroups (e.g., location, size, operator). Results: Mean lesion diameter was 32.5 (range 3.0–93.0) mm, and the mean number of samples per biopsy procedure was 3.2 (range 1–7). Mean fluoroscopy time was 161 (range 104–551) s, room time was 34 (range 15–79) min, mean DAP value was 25.9 (range 3.9–80.5) Gy·cm −2 , and interventional time was 18 (range 5–65) min. Of 84 lesions, 70 were malignant (83.3%) and 14 were benign (16.7%). Seven (8.3%) of the biopsy samples were nondiagnostic. All nondiagnostic biopsied lesions proved to be malignant during surgical resection. The outcome for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 90% (95% confidence interval [CI] 86–96), 100% (95% CI 82–100), 100% (95% CI 96–100), 66.7% (95% CI 55–83), and 91.7% (95% CI 86–96), respectively. Sixteen patients (19%) had minor and 2 (2.4%) had major complications. Conclusion: CBCT guidance is an effective method for PLB, with results comparable to CT/CT fluoroscopy guidance.

Shallow and deep breath lung tumor volume as estimated by spiral volumetric CT in comparison to standard axial CT using virtual simulation

International Nuclear Information System (INIS)

Quader, M.A.; Kalend, A.M.; Deutsch, M.; Greenberger, J.S.

1995-01-01

Purpose/Objective: In order to assess an individual patient tumor volume (TV) margins that are sufficient to design a beam-eye-view (BEW) conformal portal, the radiographic extent of gross tumor volume (GTV) dimensions and its fluctuation with breathing are measured by fast spiral CT scanning of patients treated for Stage II, III lung cancers using 5-6 field multi-collimated conformal beams. Materials and Methods: Over the course of conformal radiotherapy for lung cancer, a full thorax CT scans of the patient were taken by conventional axial CT scanning with patients immobilized in the treatment position and breathing normally. Patient(s) with good pulmonary function test (PFT) status were selected to perform deep breathing and re-scanned by fast spiral techniques in order to re-acquire the tomographic variation in the (GTV) with breathing. A Picker spiral ZAP-100 software running on the AQSim-PQ-2000 was used with a variable helical pitch of 1.0, 1.5 and 2.0. The variable pitch spirals were limited to tumor bed, diaphragm and lung apex area for measurements. Effect of breathing motion along x,y,z direction were then assessed for each beam-eye-view portal as seen in digitally reconstructed radiography (DRR) at the treated gantry angle. Results: Comparison of axial and spiral scans shows the progression of lung and diaphram motion with breathing can be gauged better in spiral scans. The movement of the diaphragm during shallow breathing has been found to be 2-3cm by measuring the distance between the most inferior and superior slices where diaphragm is present. The variation of the tumor dimensions along AP/PA and lateral direction seems to be less sensitive to breathing than those along inferior-superior direction. Conclusion: The fast spiral CT scanning is sensitive to patient lung motion and can be used to determine the fluctuations of the gross tumor volume with breathing. The extent of the fluctuation is location dependent and increases as one moves from the

Virtual Class Support at the Virtual Machine Level

DEFF Research Database (Denmark)

Nielsen, Anders Bach; Ernst, Erik

2009-01-01

This paper describes how virtual classes can be supported in a virtual machine.  Main-stream virtual machines such as the Java Virtual Machine and the .NET platform dominate the world today, and many languages are being executed on these virtual machines even though their embodied design choices...... conflict with the design choices of the virtual machine.  For instance, there is a non-trivial mismatch between the main-stream virtual machines mentioned above and dynamically typed languages.  One language concept that creates an even greater mismatch is virtual classes, in particular because fully...... general support for virtual classes requires generation of new classes at run-time by mixin composition.  Languages like CaesarJ and ObjectTeams can express virtual classes restricted to the subset that does not require run-time generation of classes, because of the restrictions imposed by the Java...

Virtual reality aided visualization of fluid flow simulations with application in medical education and diagnostics.

Science.gov (United States)

Djukic, Tijana; Mandic, Vesna; Filipovic, Nenad

2013-12-01

Medical education, training and preoperative diagnostics can be drastically improved with advanced technologies, such as virtual reality. The method proposed in this paper enables medical doctors and students to visualize and manipulate three-dimensional models created from CT or MRI scans, and also to analyze the results of fluid flow simulations. Simulation of fluid flow using the finite element method is performed, in order to compute the shear stress on the artery walls. The simulation of motion through the artery is also enabled. The virtual reality system proposed here could shorten the length of training programs and make the education process more effective. © 2013 Published by Elsevier Ltd.

Analysis of the acceptance procedure and quality control a virtual simulation system; Analisis del procedimiento de aceptacion y control de calidad de un sistema de simulacion virtual

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Ruiz, C.; Pedrero de Aristizabal, D.; Jimenez Rojas, R.; Garcia Hernandez, M. J.; Ruiz Galan, G.; Ayala Lazaro, R.; Garcia Marcos, R.

2011-07-01

Acceptance has been made, determining the reference state, commissioning and implementation of control protocol virtual simulation system consists of an image acquisition unit of computerized tomography (CT), an independent external location laser locator and a simulation module associated with the existing scheduler for clinical dosimetry in radiotherapy. This paper summarizes the path followed in this process, together with the established procedure for periodic monitoring and analysis system of the results obtained in the two years of clinical and control.

Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease

International Nuclear Information System (INIS)

Numaguchi, Y.; Robinson, A.E.; Carey, J.E.

1990-01-01

The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the xenon-CT flow studies. CBF defects on xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images. (orig.)