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Sample records for computed tomography-based treatment

  1. Influence of 18F-fluorodeoxyglucose-positron emission tomography on computed tomography-based radiation treatment planning for oesophageal cancer

    International Nuclear Information System (INIS)

    Everitt, C.; Leong, T.

    2006-01-01

    The addition of positron emission tomography (PET) information to CT-based radiotherapy treatment planning has the potential to improve target volume definition through more accurate localization of the primary tumour and involved regional lymph nodes. This case report describes the first patient enrolled to a prospective study evaluating the effects of coregistered positron emission tomography/CT images on radiotherapy treatment planning for oesophageal cancer. The results show that if combined positron emission tomography/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone. For this patient, a geographic miss of tumour would have occurred if CT data alone were used for radiotherapy planning Copyright (2006) Blackwell Publishing Asia Pty Ltd

  2. Cone-beam computed tomography-based diagnosis and treatment simulation for a patient with a protrusive profile and a gummy smile

    Science.gov (United States)

    Imamura, Toshihiro; Kokai, Satoshi; Ono, Takashi

    2018-01-01

    For patients with bimaxillary protrusion, significant retraction and intrusion of the anterior teeth are sometimes essential to improve the facial profile. However, severe root resorption of the maxillary incisors occasionally occurs after treatment because of various factors. For instance, it has been reported that approximation or invasion of the incisive canal by the anterior tooth roots during retraction may cause apical root damage. Thus, determination of the position of the maxillary incisors is key for orthodontic diagnosis and treatment planning in such cases. Cone-beam computed tomography (CBCT) may be useful for simulating the post-treatment position of the maxillary incisors and surrounding structures in order to ensure safe teeth movement. Here, we present a case of Class II malocclusion with bimaxillary protrusion, wherein apical root damage due to treatment was minimized by pretreatment evaluation of the anatomical structures and simulation of the maxillary central incisor movement using CBCT. Considerable retraction and intrusion of the maxillary incisors, which resulted in a significant improvement in the facial profile and smile, were achieved without severe root resorption. Our findings suggest that CBCT-based diagnosis and treatment simulation may facilitate safe and dynamic orthodontic tooth movement, particularly in patients requiring maximum anterior tooth retraction. PMID:29732305

  3. Computed Tomography Based Three-dimensional Measurements of Spine Shortening Distance After Posterior Three-column Osteotomies for the Treatment of Severe and Stiff Scoliosis.

    Science.gov (United States)

    Li, Xue-Shi; Huang, Zi-Fang; Deng, Yao-Long; Fan, Heng-Wei; Sui, Wen-Yuan; Wang, Chong-Wen; Yang, Jun-Lin

    2017-07-15

    Retrospective study. This study is to measure and analyze the changes of three-dimensional (3D) distances of spinal column and spinal canal at the three-column osteotomy sites and address their clinical and neurologic significance. Three-column osteotomies were developed to treat severe and stiff spine deformities with insufficient understanding on the safe limit of spine shortening and the relationship between the shortening distance of the spinal column and that of the spinal canal. Records of 52 continuous patients with severe and stiff scoliosis treated with three-column spine osteotomies at our institution from July 2013 to June 2015 were reviewed. The preoperative spinal cord function classification were type A in 31 cases, type B in 10 cases, and type C in 11 cases. The types of osteotomies carried out were extended pedicle subtraction osteotomy in nine patients and posterior vertebral column resection in 43 patients. Multimodality neuromonitoring strategies were adopted intraoperatively. 3D pre- and postoperative spine models were reconstructed from the computed tomography (CT) scans. The distances of convex and concave spinal column and the spinal canal shortening were measured and analyzed. The spinal column shortening distance (SCSD) measured on the 3D models (27.8 mm) were statistically shorter than those measured intraoperatively (32.8 mm) (P column strut graft than in those with bone-on-bone fusion (P column cannot represent that of the central spinal canal in patients with severe scoliosis. The spinal column shortening procedure in appropriately selected patient groups with bone-on-bone fusion is a viable option with the CCSD being significantly shorter than the convex SCSD. 4.

  4. Computed tomography-based subclassification of chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Dirksen, Asger; Wille, Mathilde M W

    2016-01-01

    Computed tomography (CT) is an obvious modality for subclassification of COPD. Traditionally, the pulmonary involvement of chronic obstructive pulmonary disease (COPD) in smokers is understood as a combination of deleterious effects of smoking on small airways (chronic bronchitis and small airways...... observed in COPD are subtle. Furthermore, recent results indicate that emphysema may also be the essential pathophysiologic mechanism behind the airflow limitation of COPD. The definition of COPD excludes bronchiectasis as a symptomatic subtype of COPD, and CT findings in chronic bronchitis...... and exacerbations of COPD are rather unspecific. This leaves emphysema as the most obvious candidate for subclassification of COPD. Both chest radiologists and pulmonary physicians are quite familiar with the appearance of various patterns of emphysema on HRCT, such as centrilobular, panlobular, and paraseptal...

  5. Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

    Directory of Open Access Journals (Sweden)

    Vishruta A. Dumane

    2017-06-01

    Full Text Available Three dimensional planning for high-dose-rate (HDR brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS and the Groupe Européen de Curiethérapie – European Society for Radiotherapy and Oncology (GEC-ESTRO. In this document, we describe our experience with computed tomography (CT-based planning using the tandem/ring applicator. We discuss the influence of applicator geometry on doses to organs at risk (OARs, namely the bladder, rectum, and sigmoid. Through example cases with dose prescribed to point A, we demonstrate how adaptive planning can help achieve constraints to the OARs as per guidelines.

  6. Intermuscular pterygoid-temporal abscess following inferior alveolar nerve block anesthesia-A computer tomography based navigated surgical intervention: Case report and review.

    Science.gov (United States)

    Wallner, Jürgen; Reinbacher, Knut Ernst; Pau, Mauro; Feichtinger, Matthias

    2014-01-01

    Inferior alveolar nerve block (IANB) anesthesia is a common local anesthetic procedure. Although IANB anesthesia is known for its safety, complications can still occur. Today immediately or delayed occurring disorders following IANB anesthesia and their treatment are well-recognized. We present a case of a patient who developed a symptomatic abscess in the pterygoid region as a result of several inferior alveolar nerve injections. Clinical symptoms included diffuse pain, reduced mouth opening and jaw's hypomobility and were persistent under a first step conservative treatment. Since image-based navigated interventions have gained in importance and are used for various procedures a navigated surgical intervention was initiated as a second step therapy. Thus precise, atraumatic surgical intervention was performed by an optical tracking system in a difficult anatomical region. A symptomatic abscess was treated by a computed tomography-based navigated surgical intervention at our department. Advantages and disadvantages of this treatment strategy are evaluated.

  7. Intermuscular pterygoid-temporal abscess following inferior alveolar nerve block anesthesia–A computer tomography based navigated surgical intervention: Case report and review

    Science.gov (United States)

    Wallner, Jürgen; Reinbacher, Knut Ernst; Pau, Mauro; Feichtinger, Matthias

    2014-01-01

    Inferior alveolar nerve block (IANB) anesthesia is a common local anesthetic procedure. Although IANB anesthesia is known for its safety, complications can still occur. Today immediately or delayed occurring disorders following IANB anesthesia and their treatment are well-recognized. We present a case of a patient who developed a symptomatic abscess in the pterygoid region as a result of several inferior alveolar nerve injections. Clinical symptoms included diffuse pain, reduced mouth opening and jaw's hypomobility and were persistent under a first step conservative treatment. Since image-based navigated interventions have gained in importance and are used for various procedures a navigated surgical intervention was initiated as a second step therapy. Thus precise, atraumatic surgical intervention was performed by an optical tracking system in a difficult anatomical region. A symptomatic abscess was treated by a computed tomography-based navigated surgical intervention at our department. Advantages and disadvantages of this treatment strategy are evaluated. PMID:24987612

  8. Noninvasive Computed Tomography-based Risk Stratification of Lung Adenocarcinomas in the National Lung Screening Trial.

    Science.gov (United States)

    Maldonado, Fabien; Duan, Fenghai; Raghunath, Sushravya M; Rajagopalan, Srinivasan; Karwoski, Ronald A; Garg, Kavita; Greco, Erin; Nath, Hrudaya; Robb, Richard A; Bartholmai, Brian J; Peikert, Tobias

    2015-09-15

    Screening for lung cancer using low-dose computed tomography (CT) reduces lung cancer mortality. However, in addition to a high rate of benign nodules, lung cancer screening detects a large number of indolent cancers that generally belong to the adenocarcinoma spectrum. Individualized management of screen-detected adenocarcinomas would be facilitated by noninvasive risk stratification. To validate that Computer-Aided Nodule Assessment and Risk Yield (CANARY), a novel image analysis software, successfully risk stratifies screen-detected lung adenocarcinomas based on clinical disease outcomes. We identified retrospective 294 eligible patients diagnosed with lung adenocarcinoma spectrum lesions in the low-dose CT arm of the National Lung Screening Trial. The last low-dose CT scan before the diagnosis of lung adenocarcinoma was analyzed using CANARY blinded to clinical data. Based on their parametric CANARY signatures, all the lung adenocarcinoma nodules were risk stratified into three groups. CANARY risk groups were compared using survival analysis for progression-free survival. A total of 294 patients were included in the analysis. Kaplan-Meier analysis of all the 294 adenocarcinoma nodules stratified into the Good, Intermediate, and Poor CANARY risk groups yielded distinct progression-free survival curves (P < 0.0001). This observation was confirmed in the unadjusted and adjusted (age, sex, race, and smoking status) progression-free survival analysis of all stage I cases. CANARY allows the noninvasive risk stratification of lung adenocarcinomas into three groups with distinct post-treatment progression-free survival. Our results suggest that CANARY could ultimately facilitate individualized management of incidentally or screen-detected lung adenocarcinomas.

  9. Computed tomography-based anatomic characterization of proximal aortic dissection with consideration for endovascular candidacy.

    Science.gov (United States)

    Moon, Michael C; Greenberg, Roy K; Morales, Jose P; Martin, Zenia; Lu, Qingsheng; Dowdall, Joseph F; Hernandez, Adrian V

    2011-04-01

    Proximal aortic dissections are life-threatening conditions that require immediate surgical intervention to avert an untreated mortality rate that approaches 50% at 48 hours. Advances in computed tomography (CT) imaging techniques have permitted increased characterization of aortic dissection that are necessary to assess the design and applicability of new treatment paradigms. All patients presenting during a 2-year period with acute proximal aortic dissections who underwent CT scanning were reviewed in an effort to establish a detailed assessment of their aortic anatomy. Imaging studies were assessed in an effort to document the location of the primary proximal fenestration, the proximal and distal extent of the dissection, and numerous morphologic measurements pertaining to the aortic valve, root, and ascending aorta to determine the potential for an endovascular exclusion of the ascending aorta. During the study period, 162 patients presented with proximal aortic dissections. Digital high-resolution preoperative CT imaging was performed on 76 patients, and 59 scans (77%) were of adequate quality to allow assessment of anatomic suitability for treatment with an endograft. In all cases, the dissection plane was detectable, yet the primary intimal fenestration was identified in only 41% of the studies. Scans showed 24 patients (32%) appeared to be anatomically amenable to such a repair (absence of valvular involvement, appropriate length and diameter of proximal sealing regions, lack of need to occlude coronary vasculature). Of the 42 scans that were determined not to be favorable for endovascular repair, the most common exclusion finding was the absence of a proximal landing zone (n = 15; 36%). Appropriately protocoled CT imaging provides detailed anatomic information about the aortic root and ascending aorta, allowing the assessment of which dissections have proximal fenestrations that may be amenable to an endovascular repair. Copyright © 2011 Society for

  10. Small field dose delivery evaluations using cone beam optical computed tomography-based polymer gel dosimetry

    Directory of Open Access Journals (Sweden)

    Timothy Olding

    2011-01-01

    Full Text Available This paper explores the combination of cone beam optical computed tomography with an N-isopropylacrylamide (NIPAM-based polymer gel dosimeter for three-dimensional dose imaging of small field deliveries. Initial investigations indicate that cone beam optical imaging of polymer gels is complicated by scattered stray light perturbation. This can lead to significant dosimetry failures in comparison to dose readout by magnetic resonance imaging (MRI. For example, only 60% of the voxels from an optical CT dose readout of a 1 l dosimeter passed a two-dimensional Low′s gamma test (at a 3%, 3 mm criteria, relative to a treatment plan for a well-characterized pencil beam delivery. When the same dosimeter was probed by MRI, a 93% pass rate was observed. The optical dose measurement was improved after modifications to the dosimeter preparation, matching its performance with the imaging capabilities of the scanner. With the new dosimeter preparation, 99.7% of the optical CT voxels passed a Low′s gamma test at the 3%, 3 mm criteria and 92.7% at a 2%, 2 mm criteria. The fitted interjar dose responses of a small sample set of modified dosimeters prepared (a from the same gel batch and (b from different gel batches prepared on the same day were found to be in agreement to within 3.6% and 3.8%, respectively, over the full dose range. Without drawing any statistical conclusions, this experiment gives a preliminary indication that intrabatch or interbatch NIPAM dosimeters prepared on the same day should be suitable for dose sensitivity calibration.

  11. Slice image pretreatment for cone-beam computed tomography based on adaptive filter

    International Nuclear Information System (INIS)

    Huang Kuidong; Zhang Dinghua; Jin Yanfang

    2009-01-01

    According to the noise properties and the serial slice image characteristics in Cone-Beam Computed Tomography (CBCT) system, a slice image pretreatment for CBCT based on adaptive filter was proposed. The judging criterion for the noise is established firstly. All pixels are classified into two classes: adaptive center weighted modified trimmed mean (ACWMTM) filter is used for the pixels corrupted by Gauss noise and adaptive median (AM) filter is used for the pixels corrupted by impulse noise. In ACWMTM filtering algorithm, the estimated Gauss noise standard deviation in the current slice image with offset window is replaced by the estimated standard deviation in the adjacent slice image to the current with the corresponding window, so the filtering accuracy of the serial images is improved. The pretreatment experiment on CBCT slice images of wax model of hollow turbine blade shows that the method makes a good performance both on eliminating noises and on protecting details. (authors)

  12. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M. [St. Antonius Hospital Nieuwegein, Department of Radiology, Nieuwegein (Netherlands); Jong, P.A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Zanen, P.; Grutters, J.C. [University Medical Center Utrecht, Division Heart and Lungs, Utrecht (Netherlands); St. Antonius Hospital Nieuwegein, Center of Interstitial Lung Diseases, Department of Pulmonology, Nieuwegein (Netherlands)

    2015-09-15

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  13. Feasibility of computed tomography based thermometry during interstitial laser heating in bovine liver

    International Nuclear Information System (INIS)

    Pandeya, G.D.; Klaessens, J.H.G.M.; Greuter, M.J.W.; Oudkerk, M.; Schmidt, B.; Flohr, T.; Hillegersberg, R. van

    2011-01-01

    To assess the feasibility of computed tomography (CT) based thermometry during interstitial laser heating in the bovine liver. Four freshly exercised cylindrical blocks of bovine tissue were heated using a continuous laser of Nd:YAG (wavelength: 1064 nm, active length: 30 mm, power: 10-30 W). All tissues were imaged at least once before and 7 times during laser heating using CT and temperatures were simultaneously measured with 5 calibrated thermal sensors. The dependency of the average CT numbers as a function of temperature was analysed with regression analysis and a CT thermal sensitivity was derived. During laser heating, the growing hypodense area was observed around the laser source and that area showed an increase as a function of time. The formation of hypodense area was caused by declining in CT numbers at increasing temperatures. The regression analysis showed an inverse linear dependency between temperature and average CT number with -0.65 ± 0.048 HU/ C (R 2 = 0.75) for the range of 18-85 C in bovine liver. The non-invasive CT based thermometry during interstitial laser heating is feasible in the bovine liver. CT based thermometry could be further developed and may be of potential use during clinical LITT of the liver. (orig.)

  14. A reconstruction algorithm for coherent scatter computed tomography based on filtered back-projection

    International Nuclear Information System (INIS)

    Stevendaal, U. van; Schlomka, J.-P.; Harding, A.; Grass, M.

    2003-01-01

    Coherent scatter computed tomography (CSCT) is a reconstructive x-ray imaging technique that yields the spatially resolved coherent-scatter form factor of the investigated object. Reconstruction from coherently scattered x-rays is commonly done using algebraic reconstruction techniques (ART). In this paper, we propose an alternative approach based on filtered back-projection. For the first time, a three-dimensional (3D) filtered back-projection technique using curved 3D back-projection lines is applied to two-dimensional coherent scatter projection data. The proposed algorithm is tested with simulated projection data as well as with projection data acquired with a demonstrator setup similar to a multi-line CT scanner geometry. While yielding comparable image quality as ART reconstruction, the modified 3D filtered back-projection algorithm is about two orders of magnitude faster. In contrast to iterative reconstruction schemes, it has the advantage that subfield-of-view reconstruction becomes feasible. This allows a selective reconstruction of the coherent-scatter form factor for a region of interest. The proposed modified 3D filtered back-projection algorithm is a powerful reconstruction technique to be implemented in a CSCT scanning system. This method gives coherent scatter CT the potential of becoming a competitive modality for medical imaging or nondestructive testing

  15. Incomplete projection reconstruction of computed tomography based on the modified discrete algebraic reconstruction technique

    Science.gov (United States)

    Yang, Fuqiang; Zhang, Dinghua; Huang, Kuidong; Gao, Zongzhao; Yang, YaFei

    2018-02-01

    Based on the discrete algebraic reconstruction technique (DART), this study aims to address and test a new improved algorithm applied to incomplete projection data to generate a high quality reconstruction image by reducing the artifacts and noise in computed tomography. For the incomplete projections, an augmented Lagrangian based on compressed sensing is first used in the initial reconstruction for segmentation of the DART to get higher contrast graphics for boundary and non-boundary pixels. Then, the block matching 3D filtering operator was used to suppress the noise and to improve the gray distribution of the reconstructed image. Finally, simulation studies on the polychromatic spectrum were performed to test the performance of the new algorithm. Study results show a significant improvement in the signal-to-noise ratios (SNRs) and average gradients (AGs) of the images reconstructed from incomplete data. The SNRs and AGs of the new images reconstructed by DART-ALBM were on average 30%-40% and 10% higher than the images reconstructed by DART algorithms. Since the improved DART-ALBM algorithm has a better robustness to limited-view reconstruction, which not only makes the edge of the image clear but also makes the gray distribution of non-boundary pixels better, it has the potential to improve image quality from incomplete projections or sparse projections.

  16. Cone-beam x-ray luminescence computed tomography based on x-ray absorption dosage

    Science.gov (United States)

    Liu, Tianshuai; Rong, Junyan; Gao, Peng; Zhang, Wenli; Liu, Wenlei; Zhang, Yuanke; Lu, Hongbing

    2018-02-01

    With the advances of x-ray excitable nanophosphors, x-ray luminescence computed tomography (XLCT) has become a promising hybrid imaging modality. In particular, a cone-beam XLCT (CB-XLCT) system has demonstrated its potential in in vivo imaging with the advantage of fast imaging speed over other XLCT systems. Currently, the imaging models of most XLCT systems assume that nanophosphors emit light based on the intensity distribution of x-ray within the object, not completely reflecting the nature of the x-ray excitation process. To improve the imaging quality of CB-XLCT, an imaging model that adopts an excitation model of nanophosphors based on x-ray absorption dosage is proposed in this study. To solve the ill-posed inverse problem, a reconstruction algorithm that combines the adaptive Tikhonov regularization method with the imaging model is implemented for CB-XLCT reconstruction. Numerical simulations and phantom experiments indicate that compared with the traditional forward model based on x-ray intensity, the proposed dose-based model could improve the image quality of CB-XLCT significantly in terms of target shape, localization accuracy, and image contrast. In addition, the proposed model behaves better in distinguishing closer targets, demonstrating its advantage in improving spatial resolution.

  17. Cone Beam X-ray Luminescence Computed Tomography Based on Bayesian Method.

    Science.gov (United States)

    Zhang, Guanglei; Liu, Fei; Liu, Jie; Luo, Jianwen; Xie, Yaoqin; Bai, Jing; Xing, Lei

    2017-01-01

    X-ray luminescence computed tomography (XLCT), which aims to achieve molecular and functional imaging by X-rays, has recently been proposed as a new imaging modality. Combining the principles of X-ray excitation of luminescence-based probes and optical signal detection, XLCT naturally fuses functional and anatomical images and provides complementary information for a wide range of applications in biomedical research. In order to improve the data acquisition efficiency of previously developed narrow-beam XLCT, a cone beam XLCT (CB-XLCT) mode is adopted here to take advantage of the useful geometric features of cone beam excitation. Practically, a major hurdle in using cone beam X-ray for XLCT is that the inverse problem here is seriously ill-conditioned, hindering us to achieve good image quality. In this paper, we propose a novel Bayesian method to tackle the bottleneck in CB-XLCT reconstruction. The method utilizes a local regularization strategy based on Gaussian Markov random field to mitigate the ill-conditioness of CB-XLCT. An alternating optimization scheme is then used to automatically calculate all the unknown hyperparameters while an iterative coordinate descent algorithm is adopted to reconstruct the image with a voxel-based closed-form solution. Results of numerical simulations and mouse experiments show that the self-adaptive Bayesian method significantly improves the CB-XLCT image quality as compared with conventional methods.

  18. Chest computed tomography-based scoring of thoracic sarcoidosis: Inter-rater reliability of CT abnormalities

    International Nuclear Information System (INIS)

    Heuvel, D.A.V. den; Es, H.W. van; Heesewijk, J.P. van; Spee, M.; Jong, P.A. de; Zanen, P.; Grutters, J.C.

    2015-01-01

    To determine inter-rater reliability of sarcoidosis-related computed tomography (CT) findings that can be used for scoring of thoracic sarcoidosis. CT images of 51 patients with sarcoidosis were scored by five chest radiologists for various abnormal CT findings (22 in total) encountered in thoracic sarcoidosis. Using intra-class correlation coefficient (ICC) analysis, inter-rater reliability was analysed and reported according to the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) criteria. A pre-specified sub-analysis was performed to investigate the effect of training. Scoring was trained in a distinct set of 15 scans in which all abnormal CT findings were represented. Median age of the 51 patients (36 men, 70 %) was 43 years (range 26 - 64 years). All radiographic stages were present in this group. ICC ranged from 0.91 for honeycombing to 0.11 for nodular margin (sharp versus ill-defined). The ICC was above 0.60 in 13 of the 22 abnormal findings. Sub-analysis for the best-trained observers demonstrated an ICC improvement for all abnormal findings and values above 0.60 for 16 of the 22 abnormalities. In our cohort, reliability between raters was acceptable for 16 thoracic sarcoidosis-related abnormal CT findings. (orig.)

  19. Timing of computed tomography-based postimplant assessment following permanent transperineal prostate brachytherapy

    International Nuclear Information System (INIS)

    Prestidge, Bradley R.; Bice, William S.; Kiefer, Eric J.; Prete, James J.

    1998-01-01

    Purpose: To establish the rate of resolution of prostatic edema following transperineal interstitial permanent prostate brachytherapy, and to determine the results and impact of timing of the postimplant assessment on the dose-volume relationship. Methods and Materials: A series of 19 consecutive patients with early-stage adenocarcinoma of the prostate receiving transperineal interstitial permanent prostate brachytherapy, were enrolled in this study. Twelve received 125 I and seven received 103 Pd. Postoperative assessment included a computed tomographic (CT) scan on postoperative days 1, 8, 30, 90, and 180. On each occasion, CT scans were performed on a GE helical unit at 3-mm abutting slices, 15-cm field of view. Prostate volumes were outlined on CT scans by a single clinician. Following digitization of the volumes and radioactive sources, volumes and dose-volume histograms were calculated. The prostate volume encompassed by the 80% and 100% reference isodose volumes was calculated. Results: Preimplant transrectal ultrasound determined volumes varied from 17.5 to 38.6 cc (median 27.9 cc). Prostate volumes previously defined on 40 randomly selected postimplant CT scans were compared in a blinded fashion to a second CT-derived volume and ranged from -32% to +24%. The Pearson correlation coefficient for prostate CT volume reproducibility was 0.77 (p < 0.03). CT scan-determined volume performed on postoperative day 1 was an average of 41.4% greater than the volume determined by preimplant ultrasound. Significant decreases in average volume were seen during the first month postoperatively. Average volume decreased 14% from day 1 to day 8, 10% from day 8 to day 30, 3% from day 30 to day 90, and 2% thereafter. Coverage of the prostate volume by the 80% isodose volume increased from 85.6% on postoperative day 1 to 92.2% on postoperative day 180. The corresponding increase in the 100% reference dose coverage of the prostate volume ranged from 73.1% to 83.3% between

  20. Dynamic computed tomography based on spatio-temporal analysis in acute stroke: Preliminary study

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    Park, Ha Young; Pyeon, Do Yeong; Kim, Da Hye; Jung, Young Jin [Dongseo University, Busan (Korea, Republic of)

    2016-12-15

    Acute stroke is a one of common disease that require fast diagnosis and treatment to save patients life. however, the acute stroke may cause lifelong disability due to brain damage with no prompt surgical procedure. In order to diagnose the Stroke, brain perfusion CT examination and possible rapid implementation of 3D angiography has been widely used. However, a low-dose technique should be applied for the examination since a lot of radiation exposure to the patient may cause secondary damage for the patients. Therefore, the degradation of the measured CT images may interferes with a clinical check in that blood vessel shapes o n the CT image are significantly affected by gaussian noise. In this study, we employed the spatio-temporal technique to analyze dynamic (brain perfusion) CT data to improve an image quality for successful clinical diagnosis. As a results, proposed technique could remove gaussian noise successfully, demonstrated a possibility of new image segmentation technique for CT angiography. Qualitative evaluation was conducted by skilled radiological technologists, indicated significant quality improvement of dynamic CT images. the proposed technique will be useful tools as a clinical application for brain perfusion CT examination.

  1. Clinical application of calculated split renal volume using computed tomography-based renal volumetry after partial nephrectomy: Correlation with technetium-99m dimercaptosuccinic acid renal scan data.

    Science.gov (United States)

    Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo

    2017-06-01

    To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.

  2. Use of 4-Dimensional Computed Tomography-Based Ventilation Imaging to Correlate Lung Dose and Function With Clinical Outcomes

    International Nuclear Information System (INIS)

    Vinogradskiy, Yevgeniy; Castillo, Richard; Castillo, Edward; Tucker, Susan L.; Liao, Zhongxing; Guerrero, Thomas; Martel, Mary K.

    2013-01-01

    Purpose: Four-dimensional computed tomography (4DCT)-based ventilation is an emerging imaging modality that can be used in the thoracic treatment planning process. The clinical benefit of using ventilation images in radiation treatment plans remains to be tested. The purpose of the current work was to test the potential benefit of using ventilation in treatment planning by evaluating whether dose to highly ventilated regions of the lung resulted in increased incidence of clinical toxicity. Methods and Materials: Pretreatment 4DCT data were used to compute pretreatment ventilation images for 96 lung cancer patients. Ventilation images were calculated using 4DCT data, deformable image registration, and a density-change based algorithm. Dose–volume and ventilation-based dose function metrics were computed for each patient. The ability of the dose–volume and ventilation-based dose–function metrics to predict for severe (grade 3+) radiation pneumonitis was assessed using logistic regression analysis, area under the curve (AUC) metrics, and bootstrap methods. Results: A specific patient example is presented that demonstrates how incorporating ventilation-based functional information can help separate patients with and without toxicity. The logistic regression significance values were all lower for the dose–function metrics (range P=.093-.250) than for their dose–volume equivalents (range, P=.331-.580). The AUC values were all greater for the dose–function metrics (range, 0.569-0.620) than for their dose–volume equivalents (range, 0.500-0.544). Bootstrap results revealed an improvement in model fit using dose–function metrics compared to dose–volume metrics that approached significance (range, P=.118-.155). Conclusions: To our knowledge, this is the first study that attempts to correlate lung dose and 4DCT ventilation-based function to thoracic toxicity after radiation therapy. Although the results were not significant at the .05 level, our data suggests

  3. Comparison of Real-Time Intraoperative Ultrasound-Based Dosimetry With Postoperative Computed Tomography-Based Dosimetry for Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Nag, Subir; Shi Peipei; Liu Bingren; Gupta, Nilendu; Bahnson, Robert R.; Wang, Jian Z.

    2008-01-01

    Purpose: To evaluate whether real-time intraoperative ultrasound (US)-based dosimetry can replace conventional postoperative computed tomography (CT)-based dosimetry in prostate brachytherapy. Methods and Materials: Between December 2001 and November 2002, 82 patients underwent 103 Pd prostate brachytherapy. An interplant treatment planning system was used for real-time intraoperative transrectal US-guided treatment planning. The dose distribution was updated according to the estimated seed position to obtain the dose-volume histograms. Postoperative CT-based dosimetry was performed a few hours later using the Theraplan-Plus treatment planning system. The dosimetric parameters obtained from the two imaging modalities were compared. Results: The results of this study revealed correlations between the US- and CT-based dosimetry. However, large variations were found in the implant-quality parameters of the two modalities, including the doses covering 100%, 90%, and 80% of the prostate volume and prostate volumes covered by 100%, 150%, and 200% of the prescription dose. The mean relative difference was 38% and 16% for doses covering 100% and 90% of the prostate volume and 10% and 21% for prostate volumes covered by 100% and 150% of the prescription dose, respectively. The CT-based volume covered by 200% of the prescription dose was about 30% greater than the US-based one. Compared with CT-based dosimetry, US-based dosimetry significantly underestimated the dose to normal organs, especially for the rectum. The average US-based maximal dose and volume covered by 100% of the prescription dose for the rectum was 72 Gy and 0.01 cm 3 , respectively, much lower than the 159 Gy and 0.65 cm 3 obtained using CT-based dosimetry. Conclusion: Although dosimetry using intraoperative US-based planning provides preliminary real-time information, it does not accurately reflect the postoperative CT-based dosimetry. Until studies have determined whether US-based dosimetry or

  4. Cone Beam Computed Tomography-based Evaluation of the Anterior Teeth Position Changes obtained by Passive Self-ligating Brackets.

    Science.gov (United States)

    Rhoden, Fernando K; Maltagliati, Liliana Á; de Castro Ferreira Conti, Ana C; Almeida-Pedrin, Renata R; Filho, Leopoldino C; de Almeida Cardoso, Maurício

    2016-08-01

    The objective of this study was to evaluate the anterior teeth position changes obtained by passive self-ligating brackets using cone beam computed tomography (CBCT). Twenty patients with a mean age of 16.5 years, class I malocclusion, constricted maxillary arch, and teeth crowding above 5 mm were enrolled in this study, and treated by passive orthodontic self-ligating brackets. A sequence of stainless steel thermoset wire was implemented with ending wire of 0.019" × 0.025". The CBCT and dental casts were obtained prior to the installation of orthodontic appliances (T1), and 30 days after rectangular steel wire 0.019" × 0.025" installation (T2). The measurements in CBCT were performed with the Anatomage software, and the dental casts were evaluated with a digital caliper rule with an accuracy of 0.01 mm. The CBCT data demonstrated mean buccal inclination of the upper and lower central incisors ranging from 6.55° to 7.24° respectively. The upper and lower lateral incisors ranged from 4.90° to 8.72° respectively. The lower canines showed an average increase of 3.88° in the buccal inclination and 1.96 mm in the transverse intercuspal distance. The upper canines showed a negative inclination with mean average of -0.36°, and an average increase of 0.82 mm in the transverse distance, with negative correlation with the initial crowding. Treatment with passive self-ligating brackets without obtaining spaces increases buccal inclination of the upper and lower incisors with no correlation with the amount of initial teeth crowding. The intercanine distance tends to a small increase showing different inclinations between the arches. When taking into account the self-ligating brackets, the amount of initial dental crowding is not a limitation factor that could increase the buccal inclination of the anterior teeth.

  5. Influence of Sinogram-Affirmed Iterative Reconstruction on Computed Tomography-Based Lung Volumetry and Quantification of Pulmonary Emphysema.

    Science.gov (United States)

    Baumueller, Stephan; Hilty, Regina; Nguyen, Thi Dan Linh; Weder, Walter; Alkadhi, Hatem; Frauenfelder, Thomas

    2016-01-01

    The purpose of this study was to evaluate the influence of sinogram-affirmed iterative reconstruction (SAFIRE) on quantification of lung volume and pulmonary emphysema in low-dose chest computed tomography compared with filtered back projection (FBP). Enhanced or nonenhanced low-dose chest computed tomography was performed in 20 patients with chronic obstructive pulmonary disease (group A) and in 20 patients without lung disease (group B). Data sets were reconstructed with FBP and SAFIRE strength levels 3 to 5. Two readers semiautomatically evaluated lung volumes and automatically quantified pulmonary emphysema, and another assessed image quality. Radiation dose parameters were recorded. Lung volume between FBP and SAFIRE 3 to 5 was not significantly different among both groups (all P > 0.05). When compared with those of FBP, total emphysema volume was significantly lower among reconstructions with SAFIRE 4 and 5 (mean difference, 0.56 and 0.79 L; all P emphysema is affected at higher strength levels.

  6. Breakeven analysis of computed tomography (Based on utilization of whole body C.T. scanner of SNU hospital)

    International Nuclear Information System (INIS)

    Cheung, Hwan; Choi, Myung Jun; Yoo, Chang Ho

    1986-01-01

    The C.T. scanner, an important tool for image-based diagnostics, is one of the costliest types of medical equipment. At present, there are in Korea a total of 66 units installed, and more units will be added in the future. For the fact the price of the C.T. scanner as well as scanning charge for using the equipment is very high as compared to those of the other kinds of medical equipment. The break-even analysis of computed tomography is considered fundamental as well as essential both to rational hospital management and keeping the charge for its use at an optimum level in consideration of the patient's medical expense burden. Even if pursuit of profits is not the role objective of a hospital, it cannot be denied that a break-even analysis provides an important factor for the decision making process in hospital management. The present study has the purpose of finding the ways and means to help rationalize hospital operation and improve its earning power through break-even analysis of C.T. scanner operation. For this purpose the total cost of the GE 8800 Whole Body C. T. Scanner installed at the Seoul National University Hospital was computed, and the records of its operation were analyzed. The expenses for its operation were divided into direct and indirect expenses depending on whether generation of the cost was recognized in the C. T. room or not, and the actual cost was computed for each of these accounting units

  7. Increased incidence of adrenal gland injury in blunt abdominal trauma: a computed tomography-based study from Pakistan

    Directory of Open Access Journals (Sweden)

    Aziz Muhammad Usman

    2014-02-01

    Full Text Available 【Abstract】Objective: To determine the frequency of adrenal injuries in patients presenting with blunt abdominal trauma by computed tomography (CT. Methods: During a 6 month period from January 1, 2011 to June 30, 2011, 82 emergency CT examinations were performed in the setting of major abdominal trauma and retrospectively reviewed for adrenal gland injuries. Results: A total of 7 patients were identified as having adrenal gland injuries (6 males and 1 female. Two patients had isolated adrenal gland injuries. In the other 5 patients with nonisolated injuries, injuries to the liver (1 case, spleen (1 case, retroperitoneum (2 cases and mesentery (4 cases were identified. Overall 24 cases with liver injuries (29 %, 11 cases with splenic injuries (13%, 54 cases with mesenteric injuries (65%, 14 cases (17% with retroperitoneal injuries and 9 cases with renal injuries were identified. Conclusion: Adrenal gland injury is identified in 7 patients (11.7% out of a total of 82 patients who underwent CT after major abdominal trauma. Most of these cases were nonisolated injuries. Our experience indicates that adrenal injury resulting from trauma is more common than suggested by other reports. The rise in incidence of adrenal injuries could be attributed to the mode of injury.

  8. The effects of gas diffusion layers structure on water transportation using X-ray computed tomography based Lattice Boltzmann method

    Science.gov (United States)

    Jinuntuya, Fontip; Whiteley, Michael; Chen, Rui; Fly, Ashley

    2018-02-01

    The Gas Diffusion Layer (GDL) of a Polymer Electrolyte Membrane Fuel Cell (PEMFC) plays a crucial role in overall cell performance. It is responsible for the dissemination of reactant gasses from the gas supply channels to the reactant sites at the Catalyst Layer (CL), and the adequate removal of product water from reactant sites back to the gas channels. Existing research into water transport in GDLs has been simplified to 2D estimations of GDL structures or use virtual stochastic models. This work uses X-ray computed tomography (XCT) to reconstruct three types of GDL in a model. These models are then analysed via Lattice Boltzmann methods to understand the water transport behaviours under differing contact angles and pressure differences. In this study, the three GDL samples were tested over the contact angles of 60°, 80°, 90°, 100°, 120° and 140° under applied pressure differences of 5 kPa, 10 kPa and 15 kPa. By varying the contact angle and pressure difference, it was found that the transition between stable displacement and capillary fingering is not a gradual process. Hydrophilic contact angles in the region of 60°<θ < 90° showed stable displacement properties, whereas contact angles in the region of 100°<θ < 140° displayed capillary fingering characteristics.

  9. Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

    International Nuclear Information System (INIS)

    Cho, Oyeon; Chun, Mi Son; Oh, Young Taek; Kim, Mi Hwa; Park, Hae Jin; Nam, Sang Soo; Heo, Jae Sung; Noh, O Kyu; Park, Sung Ho

    2013-01-01

    Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p 98% of prescribed dose were 99.7% for CF and 99.5% for MF. Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

  10. A dental implant-based registration method for measuring mandibular kinematics using cone beam computed tomography-based fluoroscopy.

    Science.gov (United States)

    Lin, Cheng-Chung; Chen, Chien-Chih; Chen, Yunn-Jy; Lu, Tung-Wu; Hong, Shih-Wun

    2014-01-01

    This study aimed to develop and evaluate experimentally an implant-based registration method for measuring three-dimensional (3D) kinematics of the mandible and dental implants in the mandible based on dental cone beam computed tomography (CBCT), modified to include fluoroscopic function. The proposed implant-based registration method was based on the registration of CBCT data of implants/bones with single-plane fluoroscopy images. Seven registration conditions that included one to three implants were evaluated experimentally for their performance in a cadaveric porcine headmodel. The implant-based registration method was shown to have measurement errors (SD) of less than -0.2 (0.3) mm, 1.1 (2.2) mm, and 0.7 degrees (1.3 degrees) for the in-plane translation, out-of-plane translation, and all angular components, respectively, regardless of the number of implants used. The corresponding errors were reduced to less than -0.1 (0.1) mm, -0.3 (1.7) mm, and 0.5 degree (0.4 degree) when three implants were used. An implant-based registration method was developed to measure the 3D kinematics of the mandible/implants. With its high accuracy and reliability, the new method will be useful for measuring the 3D motion of the bones/implants for relevant applications.

  11. Preclinical validation of automated dual-energy X-ray absorptiometry and computed tomography-based body composition measurements

    International Nuclear Information System (INIS)

    DEVRIESE, Joke; Pottel, Hans; BEELS, Laurence; VAN DE WIELE, Christophe; MAES, Alex; GHEYSENS, Olivier

    2016-01-01

    The aim of this study was to determine and validate a set of Hounsfield unit (HU) ranges to segment computed tomography (CT) images into tissue types and to test the validity of dual-energy X-ray absorptiometry (DXA) tissue segmentation on pure, unmixed porcine tissues. This preclinical prospective study was approved by the local ethical committee. Different quantities of porcine bone tissue (BT), lean tissue (LT) and adipose tissue (AT) were scanned using DXA and CT. Tissue type segmentation in DXA was performed via the standard clinical protocol and in CT through different sets of HU ranges. Percent coefficients of variation (%CV) were used to assess precision while % differences of observed masses were tested against zero using the Wilcoxon signed-rank Test. Total mass DXA measurements differ little but significantly (P=0.016) from true mass, while total mass CT measurements based on literature values show non-significant (P=0.69) differences of 1.7% and 2.0%. BT mass estimates with DXA differed more from true mass (median -78.2 to -75.8%) than other tissue types (median -11.3 to -8.1%). Tissue mass estimates with CT and literature HU ranges showed small differences from true mass for every tissue type (median -10.4 to 8.8%). The most suited method for automated tissue segmentation is CT and can become a valuable tool in quantitative nuclear medicine.

  12. Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

    Directory of Open Access Journals (Sweden)

    Reinhilde Jacobs

    2010-01-01

    Full Text Available Objectives: The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.Materials and Methods: Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP and mediolateral (ML diameters of the sinus were measured.Results: The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P 4 mm mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05 in maxillary sinus dimensions for partially dentate and edentulous subjects.Conclusions: Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

  13. Diagnostic value of thallium-201 myocardial perfusion IQ-SPECT without and with computed tomography-based attenuation correction to predict clinically significant and insignificant fractional flow reserve

    Science.gov (United States)

    Tanaka, Haruki; Takahashi, Teruyuki; Ohashi, Norihiko; Tanaka, Koichi; Okada, Takenori; Kihara, Yasuki

    2017-01-01

    Abstract The aim of this study was to clarify the predictive value of fractional flow reserve (FFR) determined by myocardial perfusion imaging (MPI) using thallium (Tl)-201 IQ-SPECT without and with computed tomography-based attenuation correction (CT-AC) for patients with stable coronary artery disease (CAD). We assessed 212 angiographically identified diseased vessels using adenosine-stress Tl-201 MPI-IQ-SPECT/CT in 84 consecutive, prospectively identified patients with stable CAD. We compared the FFR in 136 of the 212 diseased vessels using visual semiquantitative interpretations of corresponding territories on MPI-IQ-SPECT images without and with CT-AC. FFR inversely correlated most accurately with regional summed difference scores (rSDS) in images without and with CT-AC (r = −0.584 and r = −0.568, respectively, both P system can predict FFR at an optimal cut-off of <0.80, and we propose a novel application of CT-AC to MPI-IQ-SPECT for predicting clinically significant and insignificant FFR even in nonobese patients. PMID:29390486

  14. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tokihiro, E-mail: toyamamoto@ucdavis.edu [Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, California 95817 (United States); Kent, Michael S.; Wisner, Erik R. [Department of Surgical and Radiological Sciences, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Johnson, Lynelle R.; Stern, Joshua A. [Department of Medicine and Epidemiology, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Qi, Lihong [Department of Public Health Sciences, University of California Davis, Davis, California 95616 (United States); Fujita, Yukio [Department of Radiation Oncology, Tokai University, Isehara, Kanagawa 259-1193 (Japan); Boone, John M. [Department of Radiology, University of California Davis School of Medicine, Sacramento, California 95817 (United States)

    2016-07-15

    Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

  15. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model.

    Science.gov (United States)

    Yamamoto, Tokihiro; Kent, Michael S; Wisner, Erik R; Johnson, Lynelle R; Stern, Joshua A; Qi, Lihong; Fujita, Yukio; Boone, John M

    2016-07-01

    Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t-test. The mean TRE

  16. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

    International Nuclear Information System (INIS)

    Yamamoto, Tokihiro; Kent, Michael S.; Wisner, Erik R.; Johnson, Lynelle R.; Stern, Joshua A.; Qi, Lihong; Fujita, Yukio; Boone, John M.

    2016-01-01

    Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

  17. Efficient approach for determining four-dimensional computed tomography-based internal target volume in stereotactic radiotherapy of lung cancer

    International Nuclear Information System (INIS)

    Yeo, Seung Gu; Kim, Eun Seog

    2013-01-01

    This study aimed to investigate efficient approaches for determining internal target volume (ITV) from four-dimensional computed tomography (4D CT) images used in stereotactic body radiotherapy (SBRT) for patients with early-stage non-small cell lung cancer (NSCLC). 4D CT images were analyzed for 15 patients who received SBRT for stage I NSCLC. Three different ITVs were determined as follows: combining clinical target volume (CTV) from all 10 respiratory phases (ITV 10Phases ); combining CTV from four respiratory phases, including two extreme phases (0% and 50%) plus two intermediate phases (20% and 70%) (ITV 4Phases ); and combining CTV from two extreme phases (ITV 2Phases ). The matching index (MI) of ITV 4Phases and ITV 2Phases was defined as the ratio of ITV 4Phases and ITV 2Phases , respectively, to the ITV 10Phases . The tumor motion index (TMI) was defined as the ratio of ITV 10Phases to CTV mean , which was the mean of 10 CTVs delineated on 10 respiratory phases. The ITVs were significantly different in the order of ITV 10Phases , ITV 4Phases , and ITV 2Phases (all p 4Phases was significantly higher than that of ITV 2Phases (p 4Phases was inversely related to TMI (r = -0.569, p = 0.034). In a subgroup with low TMI (n = 7), ITV 4Phases was not statistically different from ITV 10Phases (p = 0.192) and its MI was significantly higher than that of ITV 2Phases (p = 0.016). The ITV 4Phases may be an efficient approach alternative to optimal ITV 10Phases in SBRT for early-stage NSCLC with less tumor motion.

  18. Total body height estimation using sacrum height in Anatolian Caucasians: multidetector computed tomography-based virtual anthropometry

    Energy Technology Data Exchange (ETDEWEB)

    Karakas, Hakki Muammer [Inonu University Medical Faculty, Turgut Ozal Medical Center, Department of Radiology, Malatya (Turkey); Celbis, Osman [Inonu University Medical Faculty Turgut Ozal Medical Center, Department of Forensic Medicine, Malatya (Turkey); Harma, Ahmet [Inonu University Medical Faculty Turgut Ozal Medical Center, Department of Orthopaedics and Traumatology, Malatya (Turkey); Alicioglu, Banu [Trakya University Medical Faculty, Department of Radiology, Edirne (Turkey); Trakya University Health Sciences Institute, Department of Anatomy, Edirne (Turkey)

    2011-05-15

    Estimation of total body height is a major step when a subject has to be identified from his/her skeletal structures. In the presence of decomposed skeletons and missing bones, estimation is usually based on regression equation for intact long bones. If these bones are fragmented or missing, alternative structures must be used. In this study, the value of sacrum height (SH) in total body height (TBH) estimation was investigated in a contemporary population of adult Anatolian Caucasians. Sixty-six men (41.6 {+-} 14.9 years) and 43 women (41.1 {+-} 14.2 years) were scanned with 64-row multidetector computed tomography (MDCT) to obtain high-resolution anthropometric data. SH of midsagittal sections was electronically measured. The technique and methodology were validated on a standard skeletal model. Sacrum height was 111.2 {+-} 12.6 mm (77-138 mm) in men and 104.7 {+-} 8.2 (89-125 mm) in women. The difference between the two sexes regarding SH was significant (p < 0.0001). SH did not significantly correlate with age in men, whereas the correlation was significant in women (p < 0.03). The correlation between SH and the stature was significant in men (r = 0.427, p < 0.0001) and was insignificant in women. For men the regression equation was [Stature = (0.306 x SH)+137.9] (r = 0.54, SEE = 56.9, p < 0.0001). Sacrum height is not susceptible to sex, or to age in men. In the presence of incomplete male skeletons, SH helps to determine the stature. This study is also one of the initial applications of MDCT in virtual anthropometric research. (orig.)

  19. Morphological characteristics of the posterior malleolar fragment according to ankle fracture patterns: a computed tomography-based study.

    Science.gov (United States)

    Yi, Young; Chun, Dong-Il; Won, Sung Hun; Park, Suyeon; Lee, Sanghyeon; Cho, Jaeho

    2018-02-13

    The posterior malleolar fragment (PMF) of an ankle fracture can have various shapes depending on the injury mechanism. The purpose of this study was to evaluate the morphological characteristics of the PMF according to the ankle fracture pattern described in the Lauge-Hansen classification by using computed tomography (CT) images. We retrospectively analyzed CT data of 107 patients (107 ankles) who underwent surgery for trimalleolar fracture from January 2012 to December 2014. The patients were divided into two groups: 76 ankles in the supination-external rotation (SER) stage IV group and 31 ankles in the pronation-external rotation (PER) stage IV group. The PMF type of the two groups was assessed using the Haraguchi and Jan Bartonicek classification. The cross angle (α), fragment length ratio (FLR), fragment area ratio (FAR), sagittal angle (θ), and fragment height (FH) were measured to assess the morphological characteristics of the PMF. The PMF in the SER group mainly had a posterolateral shape, whereas that in the PER group mainly had a posteromedial two-part shape or a large posterolateral triangular shape (P = 0.02). The average cross angle was not significantly different between the two groups (SER group = 19.4°, PER group = 17.6°). The mean FLR and FH were significantly larger in the PER group than in the SER group (P = 0.024, P = 0.006). The mean fragment sagittal angle in the PER group was significantly smaller than that in the SER group (P = 0.017). With regard to the articular involvement, volume, and vertical nature, the SER-type fracture tends to have a smaller fragment due to the rotational force, whereas the PER-type fracture tends to have a larger fragment due to the combination of rotational and axial forces.

  20. Total body height estimation using sacrum height in Anatolian Caucasians: multidetector computed tomography-based virtual anthropometry

    International Nuclear Information System (INIS)

    Karakas, Hakki Muammer; Celbis, Osman; Harma, Ahmet; Alicioglu, Banu

    2011-01-01

    Estimation of total body height is a major step when a subject has to be identified from his/her skeletal structures. In the presence of decomposed skeletons and missing bones, estimation is usually based on regression equation for intact long bones. If these bones are fragmented or missing, alternative structures must be used. In this study, the value of sacrum height (SH) in total body height (TBH) estimation was investigated in a contemporary population of adult Anatolian Caucasians. Sixty-six men (41.6 ± 14.9 years) and 43 women (41.1 ± 14.2 years) were scanned with 64-row multidetector computed tomography (MDCT) to obtain high-resolution anthropometric data. SH of midsagittal sections was electronically measured. The technique and methodology were validated on a standard skeletal model. Sacrum height was 111.2 ± 12.6 mm (77-138 mm) in men and 104.7 ± 8.2 (89-125 mm) in women. The difference between the two sexes regarding SH was significant (p < 0.0001). SH did not significantly correlate with age in men, whereas the correlation was significant in women (p < 0.03). The correlation between SH and the stature was significant in men (r = 0.427, p < 0.0001) and was insignificant in women. For men the regression equation was [Stature = (0.306 x SH)+137.9] (r = 0.54, SEE = 56.9, p < 0.0001). Sacrum height is not susceptible to sex, or to age in men. In the presence of incomplete male skeletons, SH helps to determine the stature. This study is also one of the initial applications of MDCT in virtual anthropometric research. (orig.)

  1. Energy-angle correlation correction algorithm for monochromatic computed tomography based on Thomson scattering X-ray source

    Science.gov (United States)

    Chi, Zhijun; Du, Yingchao; Huang, Wenhui; Tang, Chuanxiang

    2017-12-01

    The necessity for compact and relatively low cost x-ray sources with monochromaticity, continuous tunability of x-ray energy, high spatial coherence, straightforward polarization control, and high brightness has led to the rapid development of Thomson scattering x-ray sources. To meet the requirement of in-situ monochromatic computed tomography (CT) for large-scale and/or high-attenuation materials based on this type of x-ray source, there is an increasing demand for effective algorithms to correct the energy-angle correlation. In this paper, we take advantage of the parametrization of the x-ray attenuation coefficient to resolve this problem. The linear attenuation coefficient of a material can be decomposed into a linear combination of the energy-dependent photoelectric and Compton cross-sections in the keV energy regime without K-edge discontinuities, and the line integrals of the decomposition coefficients of the above two parts can be determined by performing two spectrally different measurements. After that, the line integral of the linear attenuation coefficient of an imaging object at a certain interested energy can be derived through the above parametrization formula, and monochromatic CT can be reconstructed at this energy using traditional reconstruction methods, e.g., filtered back projection or algebraic reconstruction technique. Not only can monochromatic CT be realized, but also the distributions of the effective atomic number and electron density of the imaging object can be retrieved at the expense of dual-energy CT scan. Simulation results validate our proposal and will be shown in this paper. Our results will further expand the scope of application for Thomson scattering x-ray sources.

  2. A computed tomography-based spatial normalization for the analysis of [18F] fluorodeoxyglucose positron emission tomography of the brain.

    Science.gov (United States)

    Cho, Hanna; Kim, Jin Su; Choi, Jae Yong; Ryu, Young Hoon; Lyoo, Chul Hyoung

    2014-01-01

    We developed a new computed tomography (CT)-based spatial normalization method and CT template to demonstrate its usefulness in spatial normalization of positron emission tomography (PET) images with [(18)F] fluorodeoxyglucose (FDG) PET studies in healthy controls. Seventy healthy controls underwent brain CT scan (120 KeV, 180 mAs, and 3 mm of thickness) and [(18)F] FDG PET scans using a PET/CT scanner. T1-weighted magnetic resonance (MR) images were acquired for all subjects. By averaging skull-stripped and spatially-normalized MR and CT images, we created skull-stripped MR and CT templates for spatial normalization. The skull-stripped MR and CT images were spatially normalized to each structural template. PET images were spatially normalized by applying spatial transformation parameters to normalize skull-stripped MR and CT images. A conventional perfusion PET template was used for PET-based spatial normalization. Regional standardized uptake values (SUV) measured by overlaying the template volume of interest (VOI) were compared to those measured with FreeSurfer-generated VOI (FSVOI). All three spatial normalization methods underestimated regional SUV values by 0.3-20% compared to those measured with FSVOI. The CT-based method showed slightly greater underestimation bias. Regional SUV values derived from all three spatial normalization methods were correlated significantly (p normalization may be an alternative method for structure-based spatial normalization of [(18)F] FDG PET when MR imaging is unavailable. Therefore, it is useful for PET/CT studies with various radiotracers whose uptake is expected to be limited to specific brain regions or highly variable within study population.

  3. Investigation of four-dimensional computed tomography-based pulmonary ventilation imaging in patients with emphysematous lung regions

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tokihiro; Loo, Billy W Jr; Keall, Paul J [Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Dr, Stanford, CA 94305-5847 (United States); Kabus, Sven; Lorenz, Cristian; Von Berg, Jens; Blaffert, Thomas [Department of Digital Imaging, Philips Research Europe, Roentgenstrasse 24-26, D-22335 Hamburg (Germany); Klinder, Tobias, E-mail: Tokihiro@stanford.edu [Clinical Informatics, Interventional, and Translational Solutions, Philips Research North America, Briarcliff Manor, NY 10510 (United States)

    2011-04-07

    A pulmonary ventilation imaging technique based on four-dimensional (4D) computed tomography (CT) has advantages over existing techniques. However, physiologically accurate 4D-CT ventilation imaging has not been achieved in patients. The purpose of this study was to evaluate 4D-CT ventilation imaging by correlating ventilation with emphysema. Emphysematous lung regions are less ventilated and can be used as surrogates for low ventilation. We tested the hypothesis: 4D-CT ventilation in emphysematous lung regions is significantly lower than in non-emphysematous regions. Four-dimensional CT ventilation images were created for 12 patients with emphysematous lung regions as observed on CT, using a total of four combinations of two deformable image registration (DIR) algorithms: surface-based (DIR{sup sur}) and volumetric (DIR{sup vol}), and two metrics: Hounsfield unit (HU) change (V{sub HU}) and Jacobian determinant of deformation (V{sub Jac}), yielding four ventilation image sets per patient. Emphysematous lung regions were detected by density masking. We tested our hypothesis using the one-tailed t-test. Visually, different DIR algorithms and metrics yielded spatially variant 4D-CT ventilation images. The mean ventilation values in emphysematous lung regions were consistently lower than in non-emphysematous regions for all the combinations of DIR algorithms and metrics. V{sub HU} resulted in statistically significant differences for both DIR{sup sur} (0.14 {+-} 0.14 versus 0.29 {+-} 0.16, p = 0.01) and DIR{sup vol} (0.13 {+-} 0.13 versus 0.27 {+-} 0.15, p < 0.01). However, V{sub Jac} resulted in non-significant differences for both DIR{sup sur} (0.15 {+-} 0.07 versus 0.17 {+-} 0.08, p = 0.20) and DIR{sup vol} (0.17 {+-} 0.08 versus 0.19 {+-} 0.09, p = 0.30). This study demonstrated the strong correlation between the HU-based 4D-CT ventilation and emphysema, which indicates the potential for HU-based 4D-CT ventilation imaging to achieve high physiologic accuracy. A

  4. Micro-computed tomography-based phenotypic approaches in embryology: procedural artifacts on assessments of embryonic craniofacial growth and development

    Directory of Open Access Journals (Sweden)

    Logan C Cairine

    2010-02-01

    Full Text Available Abstract Background Growing demand for three dimensional (3D digital images of embryos for purposes of phenotypic assessment drives implementation of new histological and imaging techniques. Among these micro-computed tomography (μCT has recently been utilized as an effective and practical method for generating images at resolutions permitting 3D quantitative analysis of gross morphological attributes of developing tissues and organs in embryonic mice. However, histological processing in preparation for μCT scanning induces changes in organ size and shape. Establishing normative expectations for experimentally induced changes in size and shape will be an important feature of 3D μCT-based phenotypic assessments, especially if quantifying differences in the values of those parameters between comparison sets of developing embryos is a primary aim. Toward that end, we assessed the nature and degree of morphological artifacts attending μCT scanning following use of common fixatives, using a two dimensional (2D landmark geometric morphometric approach to track the accumulation of distortions affecting the embryonic head from the native, uterine state through to fixation and subsequent scanning. Results Bouin's fixation reduced average centroid sizes of embryonic mouse crania by approximately 30% and substantially altered the morphometric shape, as measured by the shift in Procrustes distance, from the unfixed state, after the data were normalized for naturally occurring shape variation. Subsequent μCT scanning produced negligible changes in size but did appear to reduce or even reverse fixation-induced random shape changes. Mixtures of paraformaldehyde + glutaraldehyde reduced average centroid sizes by 2-3%. Changes in craniofacial shape progressively increased post-fixation. Conclusions The degree to which artifacts are introduced in the generation of random craniofacial shape variation relates to the degree of specimen dehydration during the

  5. Micro-computed tomography-based phenotypic approaches in embryology: procedural artifacts on assessments of embryonic craniofacial growth and development.

    Science.gov (United States)

    Schmidt, Eric J; Parsons, Trish E; Jamniczky, Heather A; Gitelman, Julian; Trpkov, Cvett; Boughner, Julia C; Logan, C Cairine; Sensen, Christoph W; Hallgrímsson, Benedikt

    2010-02-17

    Growing demand for three dimensional (3D) digital images of embryos for purposes of phenotypic assessment drives implementation of new histological and imaging techniques. Among these micro-computed tomography (microCT) has recently been utilized as an effective and practical method for generating images at resolutions permitting 3D quantitative analysis of gross morphological attributes of developing tissues and organs in embryonic mice. However, histological processing in preparation for microCT scanning induces changes in organ size and shape. Establishing normative expectations for experimentally induced changes in size and shape will be an important feature of 3D microCT-based phenotypic assessments, especially if quantifying differences in the values of those parameters between comparison sets of developing embryos is a primary aim. Toward that end, we assessed the nature and degree of morphological artifacts attending microCT scanning following use of common fixatives, using a two dimensional (2D) landmark geometric morphometric approach to track the accumulation of distortions affecting the embryonic head from the native, uterine state through to fixation and subsequent scanning. Bouin's fixation reduced average centroid sizes of embryonic mouse crania by approximately 30% and substantially altered the morphometric shape, as measured by the shift in Procrustes distance, from the unfixed state, after the data were normalized for naturally occurring shape variation. Subsequent microCT scanning produced negligible changes in size but did appear to reduce or even reverse fixation-induced random shape changes. Mixtures of paraformaldehyde + glutaraldehyde reduced average centroid sizes by 2-3%. Changes in craniofacial shape progressively increased post-fixation. The degree to which artifacts are introduced in the generation of random craniofacial shape variation relates to the degree of specimen dehydration during the initial fixation. Fixation methods that

  6. Variabilities of Magnetic Resonance Imaging-, Computed Tomography-, and Positron Emission Tomography-Computed Tomography-Based Tumor and Lymph Node Delineations for Lung Cancer Radiation Therapy Planning.

    Science.gov (United States)

    Karki, Kishor; Saraiya, Siddharth; Hugo, Geoffrey D; Mukhopadhyay, Nitai; Jan, Nuzhat; Schuster, Jessica; Schutzer, Matthew; Fahrner, Lester; Groves, Robert; Olsen, Kathryn M; Ford, John C; Weiss, Elisabeth

    2017-09-01

    To investigate interobserver delineation variability for gross tumor volumes of primary lung tumors and associated pathologic lymph nodes using magnetic resonance imaging (MRI), and to compare the results with computed tomography (CT) alone- and positron emission tomography (PET)-CT-based delineations. Seven physicians delineated the tumor volumes of 10 patients for the following scenarios: (1) CT only, (2) PET-CT fusion images registered to CT ("clinical standard"), and (3) postcontrast T1-weighted MRI registered with diffusion-weighted MRI. To compute interobserver variability, the median surface was generated from all observers' contours and used as the reference surface. A physician labeled the interface types (tumor to lung, atelectasis (collapsed lung), hilum, mediastinum, or chest wall) on the median surface. Contoured volumes and bidirectional local distances between individual observers' contours and the reference contour were analyzed. Computed tomography- and MRI-based tumor volumes normalized relative to PET-CT-based volumes were 1.62 ± 0.76 (mean ± standard deviation) and 1.38 ± 0.44, respectively. Volume differences between the imaging modalities were not significant. Between observers, the mean normalized volumes per patient averaged over all patients varied significantly by a factor of 1.6 (MRI) and 2.0 (CT and PET-CT) (P=4.10 × 10 -5 to 3.82 × 10 -9 ). The tumor-atelectasis interface had a significantly higher variability than other interfaces for all modalities combined (P=.0006). The interfaces with the smallest uncertainties were tumor-lung (on CT) and tumor-mediastinum (on PET-CT and MRI). Although MRI-based contouring showed overall larger variability than PET-CT, contouring variability depended on the interface type and was not significantly different between modalities, despite the limited observer experience with MRI. Multimodality imaging and combining different imaging characteristics might be the best approach to define

  7. Diagnostic accuracy of a volume-rendered computed tomography movie and other computed tomography-based imaging methods in assessment of renal vascular anatomy for laparoscopic donor nephrectomy.

    Science.gov (United States)

    Yamamoto, Shingo; Tanooka, Masao; Ando, Kumiko; Yamano, Toshiko; Ishikura, Reiichi; Nojima, Michio; Hirota, Shozo; Shima, Hiroki

    2009-12-01

    To evaluate the diagnostic accuracy of computed tomography (CT)-based imaging methods for assessing renal vascular anatomy, imaging studies, including standard axial CT, three-dimensional volume-rendered CT (3DVR-CT), and a 3DVR-CT movie, were performed on 30 patients who underwent laparoscopic donor nephrectomy (10 right side, 20 left side) for predicting the location of the renal arteries and renal, adrenal, gonadal, and lumbar veins. These findings were compared with videos obtained during the operation. Two of 37 renal arteries observed intraoperatively were missed by standard axial CT and 3DVR-CT, whereas all arteries were identified by the 3DVR-CT movie. Two of 36 renal veins were missed by standard axial CT and 3DVR-CT, whereas 1 was missed by the 3DVR-CT movie. In 20 left renal hilar anatomical structures, 20 adrenal, 20 gonadal, and 22 lumbar veins were observed during the operation. Preoperatively, the standard axial CT, 3DVR-CT, and 3DVR-CT movie detected 11, 19, and 20 adrenal veins; 13, 14, and 19 gonadal veins; and 6, 11, and 15 lumbar veins, respectively. Overall, of 135 renal vascular structures, the standard axial CT, 3DVR-CT, and 3DVR-CT movie accurately detected 99 (73.3%), 113 (83.7%), and 126 (93.3%) vessels, respectively, which indicated that the 3DVR-CT movie demonstrated a significantly higher detection rate than other CT-based imaging methods (P renal vascular anatomy before laparoscopic donor nephrectomy.

  8. Diagnostic value of thallium-201 myocardial perfusion IQ-SPECT without and with computed tomography-based attenuation correction to predict clinically significant and insignificant fractional flow reserve: A single-center prospective study.

    Science.gov (United States)

    Tanaka, Haruki; Takahashi, Teruyuki; Ohashi, Norihiko; Tanaka, Koichi; Okada, Takenori; Kihara, Yasuki

    2017-12-01

    The aim of this study was to clarify the predictive value of fractional flow reserve (FFR) determined by myocardial perfusion imaging (MPI) using thallium (Tl)-201 IQ-SPECT without and with computed tomography-based attenuation correction (CT-AC) for patients with stable coronary artery disease (CAD).We assessed 212 angiographically identified diseased vessels using adenosine-stress Tl-201 MPI-IQ-SPECT/CT in 84 consecutive, prospectively identified patients with stable CAD. We compared the FFR in 136 of the 212 diseased vessels using visual semiquantitative interpretations of corresponding territories on MPI-IQ-SPECT images without and with CT-AC.FFR inversely correlated most accurately with regional summed difference scores (rSDS) in images without and with CT-AC (r = -0.584 and r = -0.568, respectively, both P system can predict FFR at an optimal cut-off of reserved.

  9. Customized Computed Tomography-Based Boost Volumes in Breast-Conserving Therapy: Use of Three-Dimensional Histologic Information for Clinical Target Volume Margins

    International Nuclear Information System (INIS)

    Hanbeukers, Bianca; Borger, Jacques; Ende, Piet van den; Ent, Fred van der; Houben, Ruud; Jager, Jos; Keymeulen, Kristien; Murrer, Lars; Sastrowijoto, Suprapto; Vijver, Koen van de; Boersma, Liesbeth

    2009-01-01

    Purpose: To determine the difference in size between computed tomography (CT)-based irradiated boost volumes and simulator-based irradiated volumes in patients treated with breast-conserving therapy and to analyze whether the use of anisotropic three-dimensional clinical target volume (CTV) margins using the histologically determined free resection margins allows for a significant reduction of the CT-based boost volumes. Patients and Methods: The CT data from 49 patients were used to delineate a planning target volume (PTV) with isotropic CTV margins and to delineate a PTV sim that mimicked the PTV as delineated in the era of conventional simulation. For 17 patients, a PTV with anisotropic CTV margins was defined by applying customized three-dimensional CTV margins, according to the free excision margins in six directions. Boost treatment plans consisted of conformal portals for the CT-based PTVs and rectangular fields for the PTV sim . Results: The irradiated volume (volume receiving ≥95% of the prescribed dose [V 95 ]) for the PTV with isotropic CTV margins was 1.6 times greater than that for the PTV sim : 228 cm 3 vs. 147 cm 3 (p 95 was similar to the V 95 for the PTV sim (190 cm 3 vs. 162 cm 3 ; p = NS). The main determinant for the irradiated volume was the size of the excision cavity (p < .001), which was mainly related to the interval between surgery and the planning CT scan (p = .029). Conclusion: CT-based PTVs with isotropic margins for the CTV yield much greater irradiated volumes than fluoroscopically based PTVs. Applying individualized anisotropic CTV margins allowed for a significant reduction of the irradiated boost volume.

  10. Survival outcomes after radiation therapy for stage III non-small-cell lung cancer after adoption of computed tomography-based simulation.

    Science.gov (United States)

    Chen, Aileen B; Neville, Bridget A; Sher, David J; Chen, Kun; Schrag, Deborah

    2011-06-10

    Technical studies suggest that computed tomography (CT) -based simulation improves the therapeutic ratio for thoracic radiation therapy (TRT), although few studies have evaluated its use or impact on outcomes. We used the Surveillance, Epidemiology and End Results (SEER) -Medicare linked data to identify CT-based simulation for TRT among Medicare beneficiaries diagnosed with stage III non-small-cell lung cancer (NSCLC) between 2000 and 2005. Demographic and clinical factors associated with use of CT simulation were identified, and the impact of CT simulation on survival was analyzed by using Cox models and propensity score analysis. The proportion of patients treated with TRT who had CT simulation increased from 2.4% in 1994 to 34.0% in 2000 to 77.6% in 2005. Of the 5,540 patients treated with TRT from 2000 to 2005, 60.1% had CT simulation. Geographic variation was seen in rates of CT simulation, with lower rates in rural areas and in the South and West compared with those in the Northeast and Midwest. Patients treated with chemotherapy were more likely to have CT simulation (65.2% v 51.2%; adjusted odds ratio, 1.67; 95% CI, 1.48 to 1.88; P simulation. Controlling for demographic and clinical characteristics, CT simulation was associated with lower risk of death (adjusted hazard ratio, 0.77; 95% CI, 0.73 to 0.82; P simulation. CT-based simulation has been widely, although not uniformly, adopted for the treatment of stage III NSCLC and is associated with higher survival among patients receiving TRT.

  11. Prostate positioning using cone-beam computer tomography based on manual soft-tissue registration. Interobserver agreement between radiation oncologists and therapists

    Energy Technology Data Exchange (ETDEWEB)

    Jereczek-Fossa, B.A.; Pobbiati, C.; Fanti, P. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); University of Milan, Milan (Italy); Santoro, L. [European Institute of Oncology, Department of Epidemiology and Biostatistics, Milan (Italy); Fodor, C.; Zerini, D. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); Vigorito, S. [European Institute of Oncology, Department of Medical Physics, Milan (Italy); Baroni, G. [Politecnico di Milano, Department of Electronics Information and Bioengineering, Milan (Italy); De Cobelli, O. [European Institute of Oncology, Department of Urology, Milan (Italy); University of Milan, Milan (Italy); Orecchia, R. [European Institute of Oncology, Department of Radiation Oncology, Milan (Italy); National Center for Oncological Hadrontherapy (CNAO) Foundation, Pavia (Italy); University of Milan, Milan (Italy)

    2014-01-15

    To check the interobserver agreement between radiation oncologists and therapists (RTT) using an on- and off-line cone-beam computer tomography (CBCT) protocol for setup verification in the radiotherapy of prostate cancer. The CBCT data from six prostate cancer patients treated with hypofractionated intensity-modulated radiotherapy (IMRT) were independently reviewed off-line by four observers (one radiation oncologist, one junior and two senior RTTs) and benchmarked with on-line CBCT positioning performed by a radiation oncologist immediately prior to treatment. CBCT positioning was based on manual soft-tissue registration. Agreement between observers was evaluated using weighted Cohen's kappa statistics. In total, 152 CBCT-based prostate positioning procedures were reviewed by each observer. The mean (± standard deviation) of the differences between off- and on-line CBCT-simCT registration translations along the three directions (antero-posterior, latero-lateral and cranio-caudal) and rotation around the antero-posterior axis were - 0.7 (3.6) mm, 1.9 (2.7) mm, 0.9 (3.6) mm and - 1.8 (5.0) degrees, respectively. Satisfactory interobserver agreement was found, being substantial (weighted kappa > 0.6) in 10 of 16 comparisons and moderate (0.41-0.60) in the remaining six comparisons. CBCT interpretation performed by RTTs is comparable to that of radiation oncologists. Our study might be helpful in the quality assurance of radiotherapy and the optimization of competencies. Further investigation should include larger sample sizes, a greater number of observers and validated methodology in order to assess interobserver variability and its impact on high-precision prostate cancer IGRT. In the future, it should enable the wider implementation of complex and evolving radiotherapy technologies. (orig.)

  12. SU-F-T-398: Improving Radiotherapy Treatment Planning Using Dual Energy Computed Tomography Based Tissue Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tomic, N; Bekerat, H; Seuntjens, J; Forghani, R; DeBlois, F; Devic, S [McGill University, Montreal, QC (Canada)

    2016-06-15

    Purpose: Both kVp settings and geometric distribution of various materials lead to significant change of the HU values, showing the largest discrepancy for high-Z materials and for the lowest CT scanning kVp setting. On the other hand, the dose distributions around low-energy brachytherapy sources are highly dependent on the architecture and composition of tissue heterogeneities in and around the implant. Both measurements and Monte Carlo calculations show that improper tissue characterization may lead to calculated dose errors of 90% for low energy and around 10% for higher energy photons. We investigated the ability of dual-energy CT (DECT) to characterize more accurately tissue equivalent materials. Methods: We used the RMI-467 heterogeneity phantom scanned in DECT mode with 3 different set-ups: first, we placed high electron density (ED) plugs within the outer ring of the phantom; then we arranged high ED plugs within the inner ring; and finally ED plugs were randomly distributed. All three setups were scanned with the same DECT technique using a single-source DECT scanner with fast kVp switching (Discovery CT750HD; GE Healthcare). Images were transferred to a GE Advantage workstation for DECT analysis. Spectral Hounsfield unit curves (SHUACs) were then generated from 50 to 140-keV, in 10-keV increments, for each plug. Results: The dynamic range of Hounsfield units shrinks with increased photon energy as the attenuation coefficients decrease. Our results show that the spread of HUs for the three different geometrical setups is the smallest at 80 keV. Furthermore, among all the energies and all materials presented, the largest difference appears at high Z tissue equivalent plugs. Conclusion: Our results suggest that dose calculations at both megavoltage and low photon energies could benefit in the vicinity of bony structures if the 80 keV reconstructed monochromatic CT image is used with the DECT protocol utilized in this work.

  13. The influence of secondary reconstruction slice thickness on NewTom 3G cone beam computed tomography-based radiological interpretation of sheep mandibular condyle fractures.

    Science.gov (United States)

    Sirin, Yigit; Guven, Koray; Horasan, Sinan; Sencan, Sabri; Bakir, Baris; Barut, Oya; Tanyel, Cem; Aral, Ali; Firat, Deniz

    2010-11-01

    The objective of this study was to examine the diagnostic accuracy of the different secondary reconstruction slice thicknesses of cone beam computed tomography (CBCT) on artificially created mandibular condyle fractures. A total of 63 sheep heads with or without condylar fractures were scanned with a NewTom 3G CBCT scanner. Multiplanar reformatted (MPR) views in 0.2-mm, 1-mm, 2-mm, and 3-mm secondary reconstruction slice thicknesses were evaluated by 7 observers. Inter- and intraobserver agreements were calculated with weighted kappa statistics. The receiver operating characteristic (ROC) curve analysis was used to statistically compare the area under the curve (AUC) of each slice thickness. The kappa coefficients varied from fair and to excellent. The AUCs of 0.2-mm and 1-mm slice thicknesses were found to be significantly higher than those of 2 mm and 3 mm for some type of fractures. CBCT was found to be accurate in detecting all variants of fractures at 0.2 mm and 1 mm. However, 2-mm and 3-mm slices were not suitable to detect fissure, complete, and comminuted types of mandibular condyle fractures. Copyright © 2010 Mosby, Inc. All rights reserved.

  14. Short-term Reproducibility of Computed Tomography-based Lung Density Measurements in Alpha-1 Antitrypsin Deficiency and Smokers with Emphysema

    International Nuclear Information System (INIS)

    Shaker, S.B.; Dirksen, A.; Laursen, L.C.; Maltbaek, N.; Christensen, L.; Sander, U.; Seersholm, N.; Skovgaard, L.T.; Nielsen, L.; Kok-Jensen, A.

    2004-01-01

    Purpose: To study the short-term reproducibility of lung density measurements by multi-slice computed tomography (CT) using three different radiation doses and three reconstruction algorithms. Material and Methods: Twenty-five patients with smoker's emphysema and 25 patients with 1-antitrypsin deficiency underwent 3 scans at 2-week intervals. Low-dose protocol was applied, and images were reconstructed with bone, detail, and soft algorithms. Total lung volume (TLV), 15th percentile density (PD-15), and relative area at -910 Hounsfield units (RA-910) were obtained from the images using Pulmo-CMS software. Reproducibility of PD-15 and RA-910 and the influence of radiation dose, reconstruction algorithm, and type of emphysema were then analysed. Results: The overall coefficient of variation of volume adjusted PD-15 for all combinations of radiation dose and reconstruction algorithm was 3.7%. The overall standard deviation of volume-adjusted RA-910 was 1.7% (corresponding to a coefficient of variation of 6.8%). Radiation dose, reconstruction algorithm, and type of emphysema had no significant influence on the reproducibility of PD-15 and RA-910. However, bone algorithm and very low radiation dose result in overestimation of the extent of emphysema. Conclusion: Lung density measurement by CT is a sensitive marker for quantitating both subtypes of emphysema. A CT-protocol with radiation dose down to 16 mAs and soft or detail reconstruction algorithm is recommended

  15. Separation of hepatic iron and fat by dual-source dual-energy computed tomography based on material decomposition: an animal study.

    Science.gov (United States)

    Ma, Jing; Song, Zhi-Qiang; Yan, Fu-Hua

    2014-01-01

    To explore the feasibility of dual-source dual-energy computed tomography (DSDECT) for hepatic iron and fat separation in vivo. All of the procedures in this study were approved by the Research Animal Resource Center of Shanghai Ruijin Hospital. Sixty rats that underwent DECT scanning were divided into the normal group, fatty liver group, liver iron group, and coexisting liver iron and fat group, according to Prussian blue and HE staining. The data for each group were reconstructed and post-processed by an iron-specific, three-material decomposition algorithm. The iron enhancement value and the virtual non-iron contrast value, which indicated overloaded liver iron and residual liver tissue, respectively, were measured. Spearman's correlation and one-way analysis of variance (ANOVA) were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups. The iron enhancement values were positively correlated with the iron pathology grading (r = 0.729, pVNC) values were negatively correlated with the fat pathology grading (r = -0.642,pVNC values (F = 25.308,pVNC values were only observed between the fat-present and fat-absent groups. Separation of hepatic iron and fat by dual energy material decomposition in vivo was feasible, even when they coexisted.

  16. Comparison of computed tomography based parametric and patient-specific finite element models of the healthy and metastatic spine using a mesh-morphing algorithm.

    Science.gov (United States)

    O'Reilly, Meaghan Anne; Whyne, Cari Marisa

    2008-08-01

    A comparative analysis of parametric and patient-specific finite element (FE) modeling of spinal motion segments. To develop patient-specific FE models of spinal motion segments using mesh-morphing methods applied to a parametric FE model. To compare strain and displacement patterns in parametric and morphed models for both healthy and metastatically involved vertebrae. Parametric FE models may be limited in their ability to fully represent patient-specific geometries and material property distributions. Generation of multiple patient-specific FE models has been limited because of computational expense. Morphing methods have been successfully used to generate multiple specimen-specific FE models of caudal rat vertebrae. FE models of a healthy and a metastatic T6-T8 spinal motion segment were analyzed with and without patient-specific material properties. Parametric and morphed models were compared using a landmark-based morphing algorithm. Morphing of the parametric FE model and including patient-specific material properties both had a strong impact on magnitudes and patterns of vertebral strain and displacement. Small but important geometric differences can be represented through morphing of parametric FE models. The mesh-morphing algorithm developed provides a rapid method for generating patient-specific FE models of spinal motion segments.

  17. A study on optimal scan conditions of big bore multi-slice computed tomography based on radiation dose and image noise

    International Nuclear Information System (INIS)

    Lee, J. S.; Ye, S. J.; Kim, E. H.

    2011-01-01

    The newly introduced Big Bore computed tomography (CT) has a possibility to increase the tube current product scan time (mA s) for compensation of image degradation due to larger gentry opening without sound guideline. The objective of this paper is to derive optimal scan conditions for Big Bore CT scanner, mainly relating to the dose of diagnostic CT. The weighted CT dose index (CTDI w ) was estimated at five typical protocols, such as head and neck, brain, paediatric, chest and abdomen. Noises were analysed in a circle of 1 or 2 cm of diameter in CT image slice. The results showed that measured CTDI w values generally follow the theoretical rule at all scanning conditions of every protocol. Although image noises decrease with increment of mA s, analysed image noises do follow the theoretical rule, but only in specific protocols. This phenomenon is presumed to result from the photon energy spectra arriving at the detection system of the Big Bore scanner. (authors)

  18. Computed Tomography-Based Occipital Condyle Morphometry in an Indian Population to Assess the Feasibility of Condylar Screws for Occipitocervical Fusion.

    Science.gov (United States)

    Srivastava, Abhishek; Nanda, Geetanjali; Mahajan, Rajat; Nanda, Ankur; Mishra, Nirajana; Karmaran, Srinivasa; Batra, Sahil; Chhabra, Harvinder Singh

    2017-12-01

    A retrospective computed tomography (CT)-based morphometric study of 82 occipital condyles in the Indian population, focusing on critical morphometric dimensions with relation to placing condylar screws. This study focused on determining the feasibility of placing occipital condylar screws in an Indian population using CT anatomical morphometric data. The occipital condylar screw is a novel technique being explored as one of the options in occipitocervical stabilization. Sex and ethnic variations in anatomical structures may restrict the feasibility of this technique in some populations. To the best of our knowledge, there are no CT-based data on an Indian population that assess the feasibility of occipital condylar screws. We measured the dimensions of 82 occipital condyles in 41 adults on coronal, sagittal, and axial reconstructed CT images. The differences were noted between the right and left sides and also between males and females. Statistical analysis was performed using the t -test, with a p -value of occipital condyle shows that condylar screws are anatomically feasible in a large portion of the Indian population. However, because a small number of population may not be suitable for this technique, meticulous study of preoperative anatomy using detailed CT data is advised.

  19. Accuracy of Cup Positioning With the Computed Tomography-Based Two-dimensional to Three-Dimensional Matched Navigation System: A Prospective, Randomized Controlled Study.

    Science.gov (United States)

    Yamada, Kazuki; Endo, Hirosuke; Tetsunaga, Tomonori; Miyake, Takamasa; Sanki, Tomoaki; Ozaki, Toshifumi

    2018-01-01

    The accuracy of various navigation systems used for total hip arthroplasty has been described, but no publications reported the accuracy of cup orientation in computed tomography (CT)-based 2D-3D (two-dimensional to three-dimensional) matched navigation. In a prospective, randomized controlled study, 80 hips including 44 with developmental dysplasia of the hips were divided into a CT-based 2D-3D matched navigation group (2D-3D group) and a paired-point matched navigation group (PPM group). The accuracy of cup orientation (absolute difference between the intraoperative record and the postoperative measurement) was compared between groups. Additionally, multiple logistic regression analysis was performed to evaluate patient factors affecting the accuracy of cup orientation in each navigation. The accuracy of cup inclination was 2.5° ± 2.2° in the 2D-3D group and 4.6° ± 3.3° in the PPM group (P = .0016). The accuracy of cup anteversion was 2.3° ± 1.7° in the 2D-3D group and 4.4° ± 3.3° in the PPM group (P = .0009). In the PPM group, the presence of roof osteophytes decreased the accuracy of cup inclination (odds ratio 8.27, P = .0140) and the absolute value of pelvic tilt had a negative influence on the accuracy of cup anteversion (odds ratio 1.27, P = .0222). In the 2D-3D group, patient factors had no effect on the accuracy of cup orientation. The accuracy of cup positioning in CT-based 2D-3D matched navigation was better than in paired-point matched navigation, and was not affected by patient factors. It is a useful system for even severely deformed pelvises such as developmental dysplasia of the hips. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Comparison of Combined X-Ray Radiography and Magnetic Resonance (XMR) Imaging-Versus Computed Tomography-Based Dosimetry for the Evaluation of Permanent Prostate Brachytherapy Implants

    International Nuclear Information System (INIS)

    Acher, Peter; Rhode, Kawal; Morris, Stephen; Gaya, Andrew; Miquel, Marc; Popert, Rick; Tham, Ivan; Nichol, Janette; McLeish, Kate; Deehan, Charles; Dasgupta, Prokar; Beaney, Ronald; Keevil, Stephen F.

    2008-01-01

    Purpose: To present a method for the dosimetric analysis of permanent prostate brachytherapy implants using a combination of stereoscopic X-ray radiography and magnetic resonance (MR) imaging (XMR) in an XMR facility, and to compare the clinical results between XMR- and computed tomography (CT)-based dosimetry. Methods and Materials: Patients who had received nonstranded iodine-125 permanent prostate brachytherapy implants underwent XMR and CT imaging 4 weeks later. Four observers outlined the prostate gland on both sets of images. Dose-volume histograms (DVHs) were derived, and agreement was compared among the observers and between the modalities. Results: A total of 30 patients were evaluated. Inherent XMR registration based on prior calibration and optical tracking required a further automatic seed registration step that revealed a median root mean square registration error of 4.2 mm (range, 1.6-11.4). The observers agreed significantly more closely on prostate base and apex positions as well as outlining contours on the MR images than on those from CT. Coefficients of variation were significantly higher for observed prostate volumes, D90, and V100 parameters on CT-based dosimetry as opposed to XMR. The XMR-based dosimetry showed little agreement with that from CT for all observers, with D90 95% limits of agreement ranges of 65, 118, 79, and 73 Gy for Observers 1, 2, 3, and 4, respectively. Conclusions: The study results showed that XMR-based dosimetry offers an alternative to other imaging modalities and registration methods with the advantages of MR-based prostate delineation and confident three-dimensional reconstruction of the implant. The XMR-derived dose-volume histograms differ from the CT-derived values and demonstrate less interobserver variability

  1. Separation of hepatic iron and fat by dual-source dual-energy computed tomography based on material decomposition: an animal study.

    Directory of Open Access Journals (Sweden)

    Jing Ma

    Full Text Available OBJECTIVE: To explore the feasibility of dual-source dual-energy computed tomography (DSDECT for hepatic iron and fat separation in vivo. MATERIALS AND METHODS: All of the procedures in this study were approved by the Research Animal Resource Center of Shanghai Ruijin Hospital. Sixty rats that underwent DECT scanning were divided into the normal group, fatty liver group, liver iron group, and coexisting liver iron and fat group, according to Prussian blue and HE staining. The data for each group were reconstructed and post-processed by an iron-specific, three-material decomposition algorithm. The iron enhancement value and the virtual non-iron contrast value, which indicated overloaded liver iron and residual liver tissue, respectively, were measured. Spearman's correlation and one-way analysis of variance (ANOVA were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups. RESULTS: The iron enhancement values were positively correlated with the iron pathology grading (r = 0.729, p<0.001. Virtual non-iron contrast (VNC values were negatively correlated with the fat pathology grading (r = -0.642,p<0.0001. Different groups showed significantly different iron enhancement values and VNC values (F = 25.308,p<0.001; F = 10.911, p<0.001, respectively. Among the groups, significant differences in iron enhancement values were only observed between the iron-present and iron-absent groups, and differences in VNC values were only observed between the fat-present and fat-absent groups. CONCLUSION: Separation of hepatic iron and fat by dual energy material decomposition in vivo was feasible, even when they coexisted.

  2. On the relationship between calcified neurocysticercosis and epilepsy in an endemic village: A large-scale, computed tomography-based population study in rural Ecuador.

    Science.gov (United States)

    Del Brutto, Oscar H; Arroyo, Gianfranco; Del Brutto, Victor J; Zambrano, Mauricio; García, Héctor H

    2017-11-01

    Using a large-scale population-based study, we aimed to assess prevalence and patterns of presentation of neurocysticercosis (NCC) and its relationship with epilepsy in community-dwellers aged ≥20 years living in Atahualpa (rural Ecuador). In a three-phase epidemiological study, individuals with suspected seizures were identified during a door-to-door survey and an interview (phase I). Then, neurologists evaluated suspected cases and randomly selected negative persons to estimate epilepsy prevalence (phase II). In phase III, all participants were offered noncontrast computed tomography (CT) for identifying NCC cases. The independent association between NCC (exposure) and epilepsy (outcome) was assessed by the use of multivariate logistic regression models adjusted for age, sex, level of education, and alcohol intake. CT findings were subsequently compared to archived brain magnetic resonance imaging in a sizable subgroup of participants. Of 1,604 villagers aged ≥20 years, 1,462 (91%) were enrolled. Forty-one persons with epilepsy (PWE) were identified, for a crude prevalence of epilepsy of 28 per 1,000 population (95% confidence interval [CI] = 20.7-38.2). A head CT was performed in 1,228 (84%) of 1,462 participants, including 39 of 41 PWE. CT showed lesions consistent with calcified parenchymal brain cysticerci in 118 (9.6%) cases (95% CI = 8.1-11.4%). No patient had other forms of NCC. Nine of 39 PWE, as opposed to 109 of 1,189 participants without epilepsy, had NCC (23.1% vs. 9.2%, p = 0.004). This difference persisted in the adjusted logistic regression model (odds ratio = 3.04, 95% CI = 1.35-6.81, p = 0.007). This large CT-based study demonstrates that PWE had three times the odds of having NCC than those without epilepsy, providing robust epidemiological evidence favoring the relationship between NCC and epilepsy. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  3. Computed Tomography-Based Imaging of Voxel-Wise Lesion Water Uptake in Ischemic Brain: Relationship Between Density and Direct Volumetry.

    Science.gov (United States)

    Broocks, Gabriel; Flottmann, Fabian; Ernst, Marielle; Faizy, Tobias Djamsched; Minnerup, Jens; Siemonsen, Susanne; Fiehler, Jens; Kemmling, Andre

    2018-04-01

    Net water uptake per volume of brain tissue may be calculated by computed tomography (CT) density, and this imaging biomarker has recently been investigated as a predictor of lesion age in acute stroke. However, the hypothesis that measurements of CT density may be used to quantify net water uptake per volume of infarct lesion has not been validated by direct volumetric measurements so far. The purpose of this study was to (1) develop a theoretical relationship between CT density reduction and net water uptake per volume of ischemic lesions and (2) confirm this relationship by quantitative in vitro and in vivo CT image analysis using direct volumetric measurements. We developed a theoretical rationale for a linear relationship between net water uptake per volume of ischemic lesions and CT attenuation. The derived relationship between water uptake and CT density was tested in vitro in a set of increasingly diluted iodine solutions with successive CT measurements. Furthermore, the consistency of this relationship was evaluated using human in vivo CT images in a retrospective multicentric cohort. In 50 edematous infarct lesions, net water uptake was determined by direct measurement of the volumetric difference between the ischemic and normal hemisphere and was correlated with net water uptake calculated by ischemic density measurements. With regard to in vitro data, water uptake by density measurement was equivalent to direct volumetric measurement (r = 0.99, P volumetry was 44.7 ± 26.8 mL and the mean percent water uptake per lesion volume was 22.7% ± 7.4%. This was equivalent to percent water uptake obtained from density measurements: 21.4% ± 6.4%. The mean difference between percent water uptake by direct volumetry and percent water uptake by CT density was -1.79% ± 3.40%, which was not significantly different from 0 (P < 0.0001). Volume of water uptake in infarct lesions can be calculated quantitatively by relative CT density measurements. Voxel-wise imaging

  4. Computer-controlled 3-D treatment delivery

    International Nuclear Information System (INIS)

    Fraass, Benedick A.

    1995-01-01

    Purpose/Objective: This course will describe the use of computer-controlled treatment delivery techniques for treatment of patients with sophisticated conformal therapy. In particular, research and implementation issues related to clinical use of computer-controlled conformal radiation therapy (CCRT) techniques will be discussed. The possible/potential advantages of CCRT techniques will be highlighted using results from clinical 3-D planning studies. Materials and Methods: In recent years, 3-D treatment planning has been used to develop and implement 3-D conformal therapy treatment techniques, and studies based on these conformal treatments have begun to show the promise of conformal therapy. This work has been followed by the development of commercially-available multileaf collimator and computer control systems for treatment machines. Using these (and other) CCRT devices, various centers are beginning to clinically use complex computer-controlled treatments. Both research and clinical CCRT treatment techniques will be discussed in this presentation. General concepts and requirements for CCRT will be mentioned. Developmental and clinical experience with CCRT techniques from a number of centers will be utilized. Results: Treatment planning, treatment preparation and treatment delivery must be approached in an integrated fashion in order to clinically implement CCRT treatment techniques, and the entire process will be discussed. Various CCRT treatment methodologies will be reviewed from operational, dosimetric, and technical points of view. The discussion will concentrate on CCRT techniques which are likely to see rather wide dissemination over the next several years, including particularly the use of multileaf collimators (MLC), dynamic and segmental conformal therapy, conformal field shaping, and other related techniques. More advanced CCRT techniques, such as the use of individualized intensity modulation of beams or segments, and the use of computer

  5. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography-Based Radiotherapy Target Volume Definition in Non-Small-Cell Lung Cancer: Delineation by Radiation Oncologists vs. Joint Outlining With a PET Radiologist?

    International Nuclear Information System (INIS)

    Hanna, Gerard G.; Carson, Kathryn J.; Lynch, Tom; McAleese, Jonathan; Cosgrove, Vivian P.; Eakin, Ruth L.; Stewart, David P.; Zatari, Ashraf; O'Sullivan, Joe M.; Hounsell, Alan R.

    2010-01-01

    Purpose: 18 F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has benefits in target volume (TV) definition in radiotherapy treatment planning (RTP) for non-small-cell lung cancer (NSCLC); however, an optimal protocol for TV delineation has not been determined. We investigate volumetric and positional variation in gross tumor volume (GTV) delineation using a planning PET/CT among three radiation oncologists and a PET radiologist. Methods and Materials: RTP PET/CT scans were performed on 28 NSCLC patients (Stage IA-IIIB) of which 14 patients received prior induction chemotherapy. Three radiation oncologists and one PET radiologist working with a fourth radiation oncologist independently delineated the GTV on CT alone (GTV CT ) and on fused PET/CT images (GTV PETCT ). The mean percentage volume change (PVC) between GTV CT and GTV PETCT for the radiation oncologists and the PVC between GTV CT and GTV PETCT for the PET radiologist were compared using the Wilcoxon signed-rank test. Concordance index (CI) was used to assess both positional and volume change between GTV CT and GTV PETCT in a single measurement. Results: For all patients, a significant difference in PVC from GTV CT to GTV PETCT exists between the radiation oncologist (median, 5.9%), and the PET radiologist (median, -0.4%, p = 0.001). However, no significant difference in median concordance index (comparing GTV CT and GTV FUSED for individual cases) was observed (PET radiologist = 0.73; radiation oncologists = 0.66; p = 0.088). Conclusions: Percentage volume changes from GTV CT to GTV PETCT were lower for the PET radiologist than for the radiation oncologists, suggesting a lower impact of PET/CT in TV delineation for the PET radiologist than for the oncologists. Guidelines are needed to standardize the use of PET/CT for TV delineation in RTP.

  6. 18F-fluorodeoxyglucose positron emission tomography/computed tomography-based radiotherapy target volume definition in non-small-cell lung cancer: delineation by radiation oncologists vs. joint outlining with a PET radiologist?

    Science.gov (United States)

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

    2010-11-15

    (18)F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has benefits in target volume (TV) definition in radiotherapy treatment planning (RTP) for non-small-cell lung cancer (NSCLC); however, an optimal protocol for TV delineation has not been determined. We investigate volumetric and positional variation in gross tumor volume (GTV) delineation using a planning PET/CT among three radiation oncologists and a PET radiologist. RTP PET/CT scans were performed on 28 NSCLC patients (Stage IA-IIIB) of which 14 patients received prior induction chemotherapy. Three radiation oncologists and one PET radiologist working with a fourth radiation oncologist independently delineated the GTV on CT alone (GTV(CT)) and on fused PET/CT images (GTV(PETCT)). The mean percentage volume change (PVC) between GTV(CT) and GTV(PETCT) for the radiation oncologists and the PVC between GTV(CT) and GTV(PETCT) for the PET radiologist were compared using the Wilcoxon signed-rank test. Concordance index (CI) was used to assess both positional and volume change between GTV(CT) and GTV(PETCT) in a single measurement. For all patients, a significant difference in PVC from GTV(CT) to GTV(PETCT) exists between the radiation oncologist (median, 5.9%), and the PET radiologist (median, -0.4%, p = 0.001). However, no significant difference in median concordance index (comparing GTV(CT) and GTV(FUSED) for individual cases) was observed (PET radiologist = 0.73; radiation oncologists = 0.66; p = 0.088). Percentage volume changes from GTV(CT) to GTV(PETCT) were lower for the PET radiologist than for the radiation oncologists, suggesting a lower impact of PET/CT in TV delineation for the PET radiologist than for the oncologists. Guidelines are needed to standardize the use of PET/CT for TV delineation in RTP. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. A high-resolution computed tomography-based scoring system to differentiate the most infectious active pulmonary tuberculosis from community-acquired pneumonia in elderly and non-elderly patients

    International Nuclear Information System (INIS)

    Yeh, Jun-Jun; Chen, Solomon Chih-Cheng; Chen, Cheng-Ren; Yeh, Ting-Chun; Lin, Hsin-Kai; Hong, Jia-Bin; Wu, Bing-Tsang; Wu, Ming-Ting

    2014-01-01

    The objective of this study was to use high-resolution computed tomography (HRCT) imaging to predict the presence of smear-positive active pulmonary tuberculosis (PTB) in elderly (at least 65 years of age) and non-elderly patients (18-65 years of age). Patients with active pulmonary infections seen from November 2010 through December 2011 received HRCT chest imaging, sputum smears for acid-fast bacilli and sputum cultures for Mycobacterium tuberculosis. Smear-positive PTB was defined as at least one positive sputum smear and a positive culture for M. tuberculosis. Multivariate logistic regression analyses were performed to determine the HRCT predictors of smear-positive active PTB, and a prediction score was developed on the basis of receiver operating characteristic curve analysis. Of 1,255 patients included, 139 were diagnosed with smear-positive active PTB. According to ROC curve analysis, the sensitivity, specificity, positive predictive value, negative predictive value, false positive rates and false negative rates were 98.6 %, 95.8 %, 78.5 %, 99.8 %, 4.2 % and 1.4 %, respectively, for diagnosing smear-positive active PTB in elderly patients, and 100.0 %, 96.9 %, 76.5 %, 100.0 %, 3.1 % and 0.0 %, respectively, for non-elderly patients. HRCT can assist in the early diagnosis of the most infectious active PTB, thereby preventing transmission and minimizing unnecessary immediate respiratory isolation. (orig.)

  8. A high-resolution computed tomography-based scoring system to differentiate the most infectious active pulmonary tuberculosis from community-acquired pneumonia in elderly and non-elderly patients

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Jun-Jun [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Section of Thoracic Imaging, Department of Chest Medicine and Family Medicine, Chiayi City (China); Chia Nan University of Pharmacy and Science, Tainan (China); Meiho University, Pingtung (China); Pingtung Christian Hospital, Pingtung (China); Chen, Solomon Chih-Cheng; Chen, Cheng-Ren [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Department of Medical Research, Chiayi City (China); Yeh, Ting-Chun; Lin, Hsin-Kai; Hong, Jia-Bin; Wu, Bing-Tsang [Ditmanson Medical Foundation Chia-Yi Christian Hospital, Department of Family Medicine, Chiayi City (China); Wu, Ming-Ting [Department of Radiology, Kaohsiung Veterans General Hospital, Section of Thoracic and Circulation Imaging, Kaohsiung (China); School of Medicine, National Yang Ming University, Faculty of Medicine, Taipei (China)

    2014-10-15

    The objective of this study was to use high-resolution computed tomography (HRCT) imaging to predict the presence of smear-positive active pulmonary tuberculosis (PTB) in elderly (at least 65 years of age) and non-elderly patients (18-65 years of age). Patients with active pulmonary infections seen from November 2010 through December 2011 received HRCT chest imaging, sputum smears for acid-fast bacilli and sputum cultures for Mycobacterium tuberculosis. Smear-positive PTB was defined as at least one positive sputum smear and a positive culture for M. tuberculosis. Multivariate logistic regression analyses were performed to determine the HRCT predictors of smear-positive active PTB, and a prediction score was developed on the basis of receiver operating characteristic curve analysis. Of 1,255 patients included, 139 were diagnosed with smear-positive active PTB. According to ROC curve analysis, the sensitivity, specificity, positive predictive value, negative predictive value, false positive rates and false negative rates were 98.6 %, 95.8 %, 78.5 %, 99.8 %, 4.2 % and 1.4 %, respectively, for diagnosing smear-positive active PTB in elderly patients, and 100.0 %, 96.9 %, 76.5 %, 100.0 %, 3.1 % and 0.0 %, respectively, for non-elderly patients. HRCT can assist in the early diagnosis of the most infectious active PTB, thereby preventing transmission and minimizing unnecessary immediate respiratory isolation. (orig.)

  9. The Different Volume Effects of Small-Bowel Toxicity During Pelvic Irradiation Between Gynecologic Patients With and Without Abdominal Surgery: A Prospective Study With Computed Tomography-Based Dosimetry

    International Nuclear Information System (INIS)

    Huang, E.-Y.; Sung, C.-C.; Ko, S.-F.; Wang, C.-J.; Yang, Kuender D.

    2007-01-01

    Purpose: To evaluate the effect of abdominal surgery on the volume effects of small-bowel toxicity during whole-pelvic irradiation in patients with gynecologic malignancies. Methods and Materials: From May 2003 through November 2006, 80 gynecologic patients without (Group I) or with (Group II) prior abdominal surgery were analyzed. We used a computed tomography (CT) planning system to measure the small-bowel volume and dosimetry. We acquired the range of small-bowel volume in 10% (V10) to 100% (V100) of dose, at 10% intervals. The onset and grade of diarrhea during whole-pelvic irradiation were recorded as small-bowel toxicity up to 39.6 Gy in 22 fractions. Results: The volume effect of Grade 2-3 diarrhea existed from V10 to V100 in Group I patients and from V60 to V100 in Group II patients on univariate analyses. The V40 of Group I and the V100 of Group II achieved most statistical significance. The mean V40 was 281 ± 27 cm 3 and 489 ± 34 cm 3 (p 3 and 132 ± 19 cm 3 (p = 0.003). Multivariate analyses revealed that V40 (p = 0.001) and V100 (p = 0.027) were independent factors for the development of Grade 2-3 diarrhea in Groups I and II, respectively. Conclusions: Gynecologic patients without and with abdominal surgery have different volume effects on small-bowel toxicity during whole-pelvic irradiation. Low-dose volume can be used as a predictive index of Grade 2 or greater diarrhea in patients without abdominal surgery. Full-dose volume is more important than low-dose volume for Grade 2 or greater diarrhea in patients with abdominal surgery

  10. Computed Tomography-Based Anatomic Assessment Overestimates Local Tumor Recurrence in Patients With Mass-like Consolidation After Stereotactic Body Radiotherapy for Early-Stage Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dunlap, Neal E. [Department of Radiation Oncology, University of Louisville, Louisville, KY (United States); Yang Wensha [Department of Radiation Oncology, Cedars Sinai Medical Center, Los Angeles, CA (United States); McIntosh, Alyson [Department of Radiation Oncology, John and Dorothy Morgan Cancer Center, Lehigh Valley Hospital, Allentown, PA (United States); Sheng, Ke [Department of Radiation Oncology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA (United States); Benedict, Stanley H.; Read, Paul W. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Larner, James M., E-mail: jml2p@virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2012-12-01

    Purpose: To investigate pulmonary radiologic changes after lung stereotactic body radiotherapy (SBRT), to distinguish between mass-like fibrosis and tumor recurrence. Methods and Materials: Eighty consecutive patients treated with 3- to 5-fraction SBRT for early-stage peripheral non-small cell lung cancer with a minimum follow-up of 12 months were reviewed. The mean biologic equivalent dose received was 150 Gy (range, 78-180 Gy). Patients were followed with serial CT imaging every 3 months. The CT appearance of consolidation was defined as diffuse or mass-like. Progressive disease on CT was defined according to Response Evaluation Criteria in Solid Tumors 1.1. Positron emission tomography (PET) CT was used as an adjunct test. Tumor recurrence was defined as a standardized uptake value equal to or greater than the pretreatment value. Biopsy was used to further assess consolidation in select patients. Results: Median follow-up was 24 months (range, 12.0-36.0 months). Abnormal mass-like consolidation was identified in 44 patients (55%), whereas diffuse consolidation was identified in 12 patients (15%), at a median time from end of treatment of 10.3 months and 11.5 months, respectively. Tumor recurrence was found in 35 of 44 patients with mass-like consolidation using CT alone. Combined with PET, 10 of the 44 patients had tumor recurrence. Tumor size (hazard ratio 1.12, P=.05) and time to consolidation (hazard ratio 0.622, P=.03) were predictors for tumor recurrence. Three consecutive increases in volume and increasing volume at 12 months after treatment in mass-like consolidation were highly specific for tumor recurrence (100% and 80%, respectively). Patients with diffuse consolidation were more likely to develop grade {>=}2 pneumonitis (odds ratio 26.5, P=.02) than those with mass-like consolidation (odds ratio 0.42, P=.07). Conclusion: Incorporating the kinetics of mass-like consolidation and PET to the current criteria for evaluating posttreatment response will

  11. Comparison of Positron Emission Tomography Quantification Using Magnetic Resonance- and Computed Tomography-Based Attenuation Correction in Physiological Tissues and Lesions: A Whole-Body Positron Emission Tomography/Magnetic Resonance Study in 66 Patients.

    Science.gov (United States)

    Seith, Ferdinand; Gatidis, Sergios; Schmidt, Holger; Bezrukov, Ilja; la Fougère, Christian; Nikolaou, Konstantin; Pfannenberg, Christina; Schwenzer, Nina

    2016-01-01

    Attenuation correction (AC) in fully integrated positron emission tomography (PET)/magnetic resonance (MR) systems plays a key role for the quantification of tracer uptake. The aim of this prospective study was to assess the accuracy of standardized uptake value (SUV) quantification using MR-based AC in direct comparison with computed tomography (CT)-based AC of the same PET data set on a large patient population. Sixty-six patients (22 female; mean [SD], 61 [11] years) were examined by means of combined PET/CT and PET/MR (11C-choline, 18F-FDG, or 68Ga-DOTATATE) subsequently. Positron emission tomography images from PET/MR examinations were corrected with MR-derived AC based on tissue segmentation (PET(MR)). The same PET data were corrected using CT-based attenuation maps (μ-maps) derived from PET/CT after nonrigid registration of the CT to the MR-based μ-map (PET(MRCT)). Positron emission tomography SUVs were quantified placing regions of interest or volumes of interest in 6 different body regions as well as PET-avid lesions, respectively. The relative differences of quantitative PET values when using MR-based AC versus CT-based AC were varying depending on the organs and body regions assessed. In detail, the mean (SD) relative differences of PET SUVs were as follows: -7.8% (11.5%), blood pool; -3.6% (5.8%), spleen; -4.4% (5.6%)/-4.1% (6.2%), liver; -0.6% (5.0%), muscle; -1.3% (6.3%), fat; -40.0% (18.7%), bone; 1.6% (4.4%), liver lesions; -6.2% (6.8%), bone lesions; and -1.9% (6.2%), soft tissue lesions. In 10 liver lesions, distinct overestimations greater than 5% were found (up to 10%). In addition, overestimations were found in 2 bone lesions and 1 soft tissue lesion adjacent to the lung (up to 28.0%). Results obtained using different PET tracers show that MR-based AC is accurate in most tissue types, with SUV deviations generally of less than 10%. In bone, however, underestimations can be pronounced, potentially leading to inaccurate SUV quantifications. In

  12. The Relationships between Metabolic Disorders (Hypertension, Dyslipidemia, and Impaired Glucose Tolerance) and Computed Tomography-Based Indices of Hepatic Steatosis or Visceral Fat Accumulation in Middle-Aged Japanese Men.

    Science.gov (United States)

    Fujibayashi, Kazutoshi; Gunji, Toshiaki; Yokokawa, Hirohide; Naito, Toshio; Sasabe, Noriko; Okumura, Mitsue; Iijima, Kimiko; Shibuya, Katsuhiko; Hisaoka, Teruhiko; Fukuda, Hiroshi

    2016-01-01

    Most studies on the relationships between metabolic disorders (hypertension, dyslipidemia, and impaired glucose tolerance) and hepatic steatosis (HS) or visceral fat accumulation (VFA) have been cross-sectional, and thus, these relationships remain unclear. We conducted a retrospective cohort study to clarify the relationships between components of metabolic disorders and HS/VFA. The participants were 615 middle-aged men who were free from serious liver disorders, diabetes, and HS/VFA and underwent multiple general health check-ups at our institution between 2009 and 2013. The data from the initial and final check-ups were used. HS and VFA were assessed by computed tomography. HS was defined as a liver to spleen attenuation ratio of ≤1.0. VFA was defined as a visceral fat cross-sectional area of ≥100 cm2 at the level of the navel. Metabolic disorders were defined using Japan's metabolic syndrome diagnostic criteria. The participants were divided into four groups based on the presence (+) or absence (-) of HS/VFA. The onset rates of each metabolic disorder were compared among the four groups. Among the participants, 521, 55, 24, and 15 were classified as HS(-)/VFA(-), HS(-)/VFA(+), HS(+)/VFA(-), and HS(+)/VFA(+), respectively, at the end of the study. Impaired glucose tolerance was more common among the participants that exhibited HS or VFA (p = 0.05). On the other hand, dyslipidemia was more common among the participants that displayed VFA (p = 0.01). It is likely that VFA is associated with impaired glucose tolerance and dyslipidemia, while HS might be associated with impaired glucose tolerance. Unfortunately, our study failed to detect associations between HS/VFA and metabolic disorders due to the low number of subjects that exhibited fat accumulation. Although our observational study had major limitations, we consider that it obtained some interesting results. HS and VFA might affect different metabolic disorders. Further large-scale longitudinal studies are

  13. The Relationships between Metabolic Disorders (Hypertension, Dyslipidemia, and Impaired Glucose Tolerance and Computed Tomography-Based Indices of Hepatic Steatosis or Visceral Fat Accumulation in Middle-Aged Japanese Men.

    Directory of Open Access Journals (Sweden)

    Kazutoshi Fujibayashi

    Full Text Available Most studies on the relationships between metabolic disorders (hypertension, dyslipidemia, and impaired glucose tolerance and hepatic steatosis (HS or visceral fat accumulation (VFA have been cross-sectional, and thus, these relationships remain unclear. We conducted a retrospective cohort study to clarify the relationships between components of metabolic disorders and HS/VFA.The participants were 615 middle-aged men who were free from serious liver disorders, diabetes, and HS/VFA and underwent multiple general health check-ups at our institution between 2009 and 2013. The data from the initial and final check-ups were used. HS and VFA were assessed by computed tomography. HS was defined as a liver to spleen attenuation ratio of ≤1.0. VFA was defined as a visceral fat cross-sectional area of ≥100 cm2 at the level of the navel. Metabolic disorders were defined using Japan's metabolic syndrome diagnostic criteria. The participants were divided into four groups based on the presence (+ or absence (- of HS/VFA. The onset rates of each metabolic disorder were compared among the four groups.Among the participants, 521, 55, 24, and 15 were classified as HS(-/VFA(-, HS(-/VFA(+, HS(+/VFA(-, and HS(+/VFA(+, respectively, at the end of the study. Impaired glucose tolerance was more common among the participants that exhibited HS or VFA (p = 0.05. On the other hand, dyslipidemia was more common among the participants that displayed VFA (p = 0.01.It is likely that VFA is associated with impaired glucose tolerance and dyslipidemia, while HS might be associated with impaired glucose tolerance. Unfortunately, our study failed to detect associations between HS/VFA and metabolic disorders due to the low number of subjects that exhibited fat accumulation. Although our observational study had major limitations, we consider that it obtained some interesting results. HS and VFA might affect different metabolic disorders. Further large-scale longitudinal studies

  14. Computational Dosimetry and Treatment Planning Considerations for Neutron Capture Therapy

    International Nuclear Information System (INIS)

    Nigg, David Waler

    2003-01-01

    Specialized treatment planning software systems are generally required for neutron capture therapy (NCT) research and clinical applications. The standard simplifying approximations that work well for treatment planning computations in the case of many other modalities are usually not appropriate for application to neutron transport. One generally must obtain an explicit three-dimensional numerical solution of the governing transport equation, with energy-dependent neutron scattering completely taken into account. Treatment planning systems that have been successfully introduced for NCT applications over the past 15 years rely on the Monte Carlo stochastic simulation method for the necessary computations, primarily because of the geometric complexity of human anatomy. However, historically, there has also been interest in the application of deterministic methods, and there have been some practical developments in this area. Most recently, interest has turned toward the creation of treatment planning software that is not limited to any specific therapy modality, with NCT as only one of several applications. A key issue with NCT treatment planning has to do with boron quantification, and whether improved information concerning the spatial biodistribution of boron can be effectively used to improve the treatment planning process. Validation and benchmarking of computations for NCT are also of current developmental interest. Various institutions have their own procedures, but standard validation models are not yet in wide use

  15. Basic user guide for the radwaste treatment plant computer system

    International Nuclear Information System (INIS)

    Keel, A.

    1990-07-01

    This guide has been produced as an aid to using the Radwaste Treatment Plant computer system. It is designed to help new users to use the database menu system. Some of the forms can be used in ways different from those explained and more complex queries can be performed. (UK)

  16. Computational models as predictors of HIV treatment outcomes for ...

    African Journals Online (AJOL)

    Background: Selecting the optimal combination of HIV drugs for an individual in resourcelimited settings is challenging because of the limited availability of drugs and genotyping. Objective: The evaluation as a potential treatment support tool of computational models that predict response to therapy without a genotype, ...

  17. Esthetic considerations for the treatment of the edentulous maxilla based on current informatic alternatives: a case report.

    Science.gov (United States)

    Rodríguez-Tizcareño, Mario H; Barajas, Lizbeth; Pérez-Gásque, Marisol; Gómez, Salvador

    2012-06-01

    This report presents a protocol used to transfer the virtual treatment plan data to the surgical and prosthetic reality and its clinical application, bone site augmentation with computer-custom milled bovine bone graft blocks to their ideal architecture form, implant insertion based on image-guided stent fabrication, and the restorative manufacturing process through computed tomography-based software programs and navigation systems and the computer-aided design and manufacturing techniques for the treatment of the edentulous maxilla.

  18. Three-dimensional treatment planning of orthognathic surgery in the era of virtual imaging.

    NARCIS (Netherlands)

    Swennen, G.R.J.; Mollemans, W.; Schutyser, F.A.C.

    2009-01-01

    PURPOSE: The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. MATERIALS AND METHODS: We have described the different stages of the workflow process for

  19. Reduction of treatment delivery variances with a computer-controlled treatment delivery system

    International Nuclear Information System (INIS)

    Fraass, B.A.; Lash, K.L.; Matrone, G.M.; Lichter, A.S.

    1997-01-01

    Purpose: To analyze treatment delivery variances for 3-D conformal therapy performed at various levels of treatment delivery automation, ranging from manual field setup to virtually complete computer-controlled treatment delivery using a computer-controlled conformal radiotherapy system. Materials and Methods: All external beam treatments performed in our department during six months of 1996 were analyzed to study treatment delivery variances versus treatment complexity. Treatments for 505 patients (40,641 individual treatment ports) on four treatment machines were studied. All treatment variances noted by treatment therapists or quality assurance reviews (39 in all) were analyzed. Machines 'M1' (CLinac (6(100))) and 'M2' (CLinac 1800) were operated in a standard manual setup mode, with no record and verify system (R/V). Machines 'M3' (CLinac 2100CD/MLC) and ''M4'' (MM50 racetrack microtron system with MLC) treated patients under the control of a computer-controlled conformal radiotherapy system (CCRS) which 1) downloads the treatment delivery plan from the planning system, 2) performs some (or all) of the machine set-up and treatment delivery for each field, 3) monitors treatment delivery, 4) records all treatment parameters, and 5) notes exceptions to the electronically-prescribed plan. Complete external computer control is not available on M3, so it uses as many CCRS features as possible, while M4 operates completely under CCRS control and performs semi-automated and automated multi-segment intensity modulated treatments. Analysis of treatment complexity was based on numbers of fields, individual segments (ports), non-axial and non-coplanar plans, multi-segment intensity modulation, and pseudo-isocentric treatments (and other plans with computer-controlled table motions). Treatment delivery time was obtained from the computerized scheduling system (for manual treatments) or from CCRS system logs. Treatment therapists rotate among the machines, so this analysis

  20. 3D Computer aided treatment planning in endodontics.

    Science.gov (United States)

    van der Meer, Wicher J; Vissink, Arjan; Ng, Yuan Ling; Gulabivala, Kishor

    2016-02-01

    Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems during root canal treatment to avoid iatrogenic damage of the root. Digital endodontic treatment planning for anterior teeth with severely obliterated root canal systems was accomplished with the aid of computer software, based on cone beam computer tomography (CBCT) scans and intra-oral scans of the dentition. On the basis of these scans, endodontic guides were created for the planned treatment through digital designing and rapid prototyping fabrication. The custom-made guides allowed for an uncomplicated and predictable canal location and management. The method of digital designing and rapid prototyping of endodontic guides allows for reliable and predictable location of root canals of teeth with calcifically metamorphosed root canal systems. The endodontic directional guide facilitates difficult endodontic treatments at little additional cost. Copyright © 2016. Published by Elsevier Ltd.

  1. COMPARATIVE STUDY OF TERTIARY WASTEWATER TREATMENT BY COMPUTER SIMULATION

    Directory of Open Access Journals (Sweden)

    Stefania Iordache

    2010-01-01

    Full Text Available The aim of this work is to asses conditions for implementation of a Biological Nutrient Removal (BNR process in theWastewater Treatment Plant (WWTP of Moreni city (Romania. In order to meet the more increased environmentalregulations, the wastewater treatment plant that was studied, must update the actual treatment process and have tomodernize it. A comparative study was undertaken of the quality of effluents that could be obtained by implementationof biological nutrient removal process like A2/O (Anaerobic/Anoxic/Oxic and VIP (Virginia Plant Initiative aswastewater tertiary treatments. In order to asses the efficiency of the proposed treatment schemata based on the datamonitored at the studied WWTP, it were realized computer models of biological nutrient removal configurations basedon A2/O and VIP process. Computer simulation was realized using a well-known simulator, BioWin by EnviroSimAssociates Ltd. The simulation process allowed to obtain some data that can be used in design of a tertiary treatmentstage at Moreni WWTP, in order to increase the efficiency in operation.

  2. A computer aided treatment event recognition system in radiation therapy

    International Nuclear Information System (INIS)

    Xia, Junyi; Mart, Christopher; Bayouth, John

    2014-01-01

    Purpose: To develop an automated system to safeguard radiation therapy treatments by analyzing electronic treatment records and reporting treatment events. Methods: CATERS (Computer Aided Treatment Event Recognition System) was developed to detect treatment events by retrieving and analyzing electronic treatment records. CATERS is designed to make the treatment monitoring process more efficient by automating the search of the electronic record for possible deviations from physician's intention, such as logical inconsistencies as well as aberrant treatment parameters (e.g., beam energy, dose, table position, prescription change, treatment overrides, etc). Over a 5 month period (July 2012–November 2012), physicists were assisted by the CATERS software in conducting normal weekly chart checks with the aims of (a) determining the relative frequency of particular events in the authors’ clinic and (b) incorporating these checks into the CATERS. During this study period, 491 patients were treated at the University of Iowa Hospitals and Clinics for a total of 7692 fractions. Results: All treatment records from the 5 month analysis period were evaluated using all the checks incorporated into CATERS after the training period. About 553 events were detected as being exceptions, although none of them had significant dosimetric impact on patient treatments. These events included every known event type that was discovered during the trial period. A frequency analysis of the events showed that the top three types of detected events were couch position override (3.2%), extra cone beam imaging (1.85%), and significant couch position deviation (1.31%). The significant couch deviation is defined as the number of treatments where couch vertical exceeded two times standard deviation of all couch verticals, or couch lateral/longitudinal exceeded three times standard deviation of all couch laterals and longitudinals. On average, the application takes about 1 s per patient when

  3. A computer aided treatment event recognition system in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Junyi, E-mail: junyi-xia@uiowa.edu; Mart, Christopher [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Bayouth, John [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Human Oncology, University of Wisconsin - Madison, 600 Highland Avenue, K4/B55, Madison, Wisconsin 53792-0600 (United States)

    2014-01-15

    Purpose: To develop an automated system to safeguard radiation therapy treatments by analyzing electronic treatment records and reporting treatment events. Methods: CATERS (Computer Aided Treatment Event Recognition System) was developed to detect treatment events by retrieving and analyzing electronic treatment records. CATERS is designed to make the treatment monitoring process more efficient by automating the search of the electronic record for possible deviations from physician's intention, such as logical inconsistencies as well as aberrant treatment parameters (e.g., beam energy, dose, table position, prescription change, treatment overrides, etc). Over a 5 month period (July 2012–November 2012), physicists were assisted by the CATERS software in conducting normal weekly chart checks with the aims of (a) determining the relative frequency of particular events in the authors’ clinic and (b) incorporating these checks into the CATERS. During this study period, 491 patients were treated at the University of Iowa Hospitals and Clinics for a total of 7692 fractions. Results: All treatment records from the 5 month analysis period were evaluated using all the checks incorporated into CATERS after the training period. About 553 events were detected as being exceptions, although none of them had significant dosimetric impact on patient treatments. These events included every known event type that was discovered during the trial period. A frequency analysis of the events showed that the top three types of detected events were couch position override (3.2%), extra cone beam imaging (1.85%), and significant couch position deviation (1.31%). The significant couch deviation is defined as the number of treatments where couch vertical exceeded two times standard deviation of all couch verticals, or couch lateral/longitudinal exceeded three times standard deviation of all couch laterals and longitudinals. On average, the application takes about 1 s per patient when

  4. The impact of treatment complexity and computer-control delivery technology on treatment delivery errors

    International Nuclear Information System (INIS)

    Fraass, Benedick A.; Lash, Kathy L.; Matrone, Gwynne M.; Volkman, Susan K.; McShan, Daniel L.; Kessler, Marc L.; Lichter, Allen S.

    1998-01-01

    Purpose: To analyze treatment delivery errors for three-dimensional (3D) conformal therapy performed at various levels of treatment delivery automation and complexity, ranging from manual field setup to virtually complete computer-controlled treatment delivery using a computer-controlled conformal radiotherapy system (CCRS). Methods and Materials: All treatment delivery errors which occurred in our department during a 15-month period were analyzed. Approximately 34,000 treatment sessions (114,000 individual treatment segments [ports]) on four treatment machines were studied. All treatment delivery errors logged by treatment therapists or quality assurance reviews (152 in all) were analyzed. Machines 'M1' and 'M2' were operated in a standard manual setup mode, with no record and verify system (R/V). MLC machines 'M3' and 'M4' treated patients under the control of the CCRS system, which (1) downloads the treatment delivery plan from the planning system; (2) performs some (or all) of the machine set up and treatment delivery for each field; (3) monitors treatment delivery; (4) records all treatment parameters; and (5) notes exceptions to the electronically-prescribed plan. Complete external computer control is not available on M3; therefore, it uses as many CCRS features as possible, while M4 operates completely under CCRS control and performs semi-automated and automated multi-segment intensity modulated treatments. Analysis of treatment complexity was based on numbers of fields, individual segments, nonaxial and noncoplanar plans, multisegment intensity modulation, and pseudoisocentric treatments studied for a 6-month period (505 patients) concurrent with the period in which the delivery errors were obtained. Treatment delivery time was obtained from the computerized scheduling system (for manual treatments) or from CCRS system logs. Treatment therapists rotate among the machines; therefore, this analysis does not depend on fixed therapist staff on particular

  5. Electron beam treatment planning: A review of dose computation methods

    International Nuclear Information System (INIS)

    Mohan, R.; Riley, R.; Laughlin, J.S.

    1983-01-01

    Various methods of dose computations are reviewed. The equivalent path length methods used to account for body curvature and internal structure are not adequate because they ignore the lateral diffusion of electrons. The Monte Carlo method for the broad field three-dimensional situation in treatment planning is impractical because of the enormous computer time required. The pencil beam technique may represent a suitable compromise. The behavior of a pencil beam may be described by the multiple scattering theory or, alternatively, generated using the Monte Carlo method. Although nearly two orders of magnitude slower than the equivalent path length technique, the pencil beam method improves accuracy sufficiently to justify its use. It applies very well when accounting for the effect of surface irregularities; the formulation for handling inhomogeneous internal structure is yet to be developed

  6. Hepatocellular carcinoma: computed tomography assessment after invasive treatment

    International Nuclear Information System (INIS)

    Kozima, Shigeru; Larranaga, Nebil; Wulfson, Gabriela; Eisele, Guillermo; Ridruejo, Ezequiel; Mando, Oscar; Perazzo, Florencia

    2008-01-01

    Objective: To show the computed tomography (CT) usefulness after treatment with transcatheter arterial quimioembolization and radiofrequency ablation of hepatocellular carcinoma. Material and methods: In a period between march 2006 to april 2008 a total of 90 patient presenting 148 nodular lesions with diagnosis of hepatocellular carcinoma were controlled with triphasic CT. All the lesions were treated with minimally invasive procedure. For the treatment, the patients were classified in two groups following Milan criteria. The first group, constituted by 75 patients with 109 nodules, was treated with quimioembolization. The second group, of 15 patients with 25 nodules, was treated with radiofrequency ablation. In our population, a subgroup of 10 patients was treated with both methods. Results: Of 90 patients after CT control on a month, 3 months and for each 3 months during 2 years, on 63 cases (70%) was observed homogeneous accumulation of iodized oil, partial defect without enhancement or absence of enhancement on treated lesions. In these patients a new treatment after initial one was not performed. The remaining 27 patients (30%) underwent new treatment because we founded partial defect or absence of iodized oil with enhancement or peripheral enhancement on arterial phase in treated lesions. In this last group, 16 treated patients (17.7%) had new nodular enhancement on the remaining hepatic parenquimal. Conclusion: The CT unenhanced and the arterial phase on a month and for each 3 months, allow monitoring the effectiveness, residual disease and/or relapse of hepatocellular carcinoma after minimally invasive treatment. (authors) [es

  7. Computer modeling of lung cancer diagnosis-to-treatment process.

    Science.gov (United States)

    Ju, Feng; Lee, Hyo Kyung; Osarogiagbon, Raymond U; Yu, Xinhua; Faris, Nick; Li, Jingshan

    2015-08-01

    We introduce an example of a rigorous, quantitative method for quality improvement in lung cancer care-delivery. Computer process modeling methods are introduced for lung cancer diagnosis, staging and treatment selection process. Two types of process modeling techniques, discrete event simulation (DES) and analytical models, are briefly reviewed. Recent developments in DES are outlined and the necessary data and procedures to develop a DES model for lung cancer diagnosis, leading up to surgical treatment process are summarized. The analytical models include both Markov chain model and closed formulas. The Markov chain models with its application in healthcare are introduced and the approach to derive a lung cancer diagnosis process model is presented. Similarly, the procedure to derive closed formulas evaluating the diagnosis process performance is outlined. Finally, the pros and cons of these methods are discussed.

  8. Orthodontics: computer-aided diagnosis and treatment planning

    Science.gov (United States)

    Yi, Yaxing; Li, Zhongke; Wei, Suyuan; Deng, Fanglin; Yao, Sen

    2000-10-01

    The purpose of this article is to introduce the outline of our newly developed computer-aided 3D dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a scanning device and a personal computer as a scanning controller and post processor. The scanning device is composed of a laser beam emitter, two sets of linear CCD cameras and a table which is rotatable by two-degree-of-freedom. The rotating is controlled precisely by a personal computer. The dental cast is projected and scanned with a laser beam. Triangulation is applied to determine the location of each point. Generation of 3D graphics of the dental cast takes approximately 40 minutes. About 170,000 sets of X,Y,Z coordinates are store for one dental cast. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the top surface area of each molar. The advantage of this system is that it facilitates the otherwise complicated and time- consuming mock surgery necessary for treatment planning in orthognathic surgery.

  9. Mixed Waste Treatment Project: Computer simulations of integrated flowsheets

    International Nuclear Information System (INIS)

    Dietsche, L.J.

    1993-12-01

    The disposal of mixed waste, that is waste containing both hazardous and radioactive components, is a challenging waste management problem of particular concern to DOE sites throughout the United States. Traditional technologies used for the destruction of hazardous wastes need to be re-evaluated for their ability to handle mixed wastes, and in some cases new technologies need to be developed. The Mixed Waste Treatment Project (MWTP) was set up by DOE's Waste Operations Program (EM30) to provide guidance on mixed waste treatment options. One of MWTP's charters is to develop flowsheets for prototype integrated mixed waste treatment facilities which can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modelling. The objective of the flowsheet simulations is to provide mass and energy balances, product compositions, and equipment sizing (leading to cost) information. The modelled flowsheets need to be easily modified to examine how alternative technologies and varying feed streams effect the overall integrated process. One such commercially available simulation program is ASPEN PLUS. This report contains details of the Aspen Plus program

  10. Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem

    International Nuclear Information System (INIS)

    William Charlton

    2007-01-01

    Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions

  11. Computed tomographic findings of splenic injury and correlation with treatment

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Koh, Joo Yaul; Kim, Myung Soon; Hong, In Soo; Cho, Whi Youl; Sung, Ki Joon

    1990-01-01

    According to recently reported classification, 46 patients with blunt splenic trauma were evaluate preoperatively with computed tomography(CT). Injures were graded I through IV and describe as capsular or subcapsular disruptions without parenchymal injury(3 patients); capsular and parenchymal injuries(23 patients); injuries involving hilum(3 patients); and fragmentation(17 patients). Nineteen patients were managed conservatively and 27 patients were managed surgically. Twelve patients(47%) out of those with Type I or Type II were managed surgically including five hemodynamically unstable patients and seven hemodynamically stable patients with associated injuries and unknown surgical criteria. On the other hand hemodynamically stable patients(25%) out of those with Type III or Type IV were managed surgically. The amount of hemoperitoneum was graded into small, moderate and large; small in three patients, moderate in 39 patients, and large in two patients. The amount of hemoperitoneum in patients with conservative treatment was moderate in 16 patients and large in one patient. And the amount of hemoperitoneum in patients with operative treatment was small in three patients, moderate in 23 patients and large in one patient. We concluded that CT was accurate method of determining the extent of splenic injury and evaluation of hemoperitoneum, but treatment choice should be based on the hemodynamic status of patients rather than the type of injury or the amount of hemoperitoneum by CT

  12. Computed tomographic findings of splenic injury and correlation with treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Jin; Koh, Joo Yaul; Kim, Myung Soon; Hong, In Soo; Cho, Whi Youl; Sung, Ki Joon [Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of)

    1990-12-15

    According to recently reported classification, 46 patients with blunt splenic trauma were evaluate preoperatively with computed tomography(CT). Injures were graded I through IV and describe as capsular or subcapsular disruptions without parenchymal injury(3 patients); capsular and parenchymal injuries(23 patients); injuries involving hilum(3 patients); and fragmentation(17 patients). Nineteen patients were managed conservatively and 27 patients were managed surgically. Twelve patients(47%) out of those with Type I or Type II were managed surgically including five hemodynamically unstable patients and seven hemodynamically stable patients with associated injuries and unknown surgical criteria. On the other hand hemodynamically stable patients(25%) out of those with Type III or Type IV were managed surgically. The amount of hemoperitoneum was graded into small, moderate and large; small in three patients, moderate in 39 patients, and large in two patients. The amount of hemoperitoneum in patients with conservative treatment was moderate in 16 patients and large in one patient. And the amount of hemoperitoneum in patients with operative treatment was small in three patients, moderate in 23 patients and large in one patient. We concluded that CT was accurate method of determining the extent of splenic injury and evaluation of hemoperitoneum, but treatment choice should be based on the hemodynamic status of patients rather than the type of injury or the amount of hemoperitoneum by CT.

  13. Nonoperative treatment of splenic trauma: usefulness of computed tomography

    International Nuclear Information System (INIS)

    Resende, Vivian; Tavares Junior, Wilson Campos; Vieira, Jose Nelson Mendes; Drumond, Domingos Andre Fernandes

    2005-01-01

    Objective: to report the results of use of conservative treatment in patients with splenic trauma and to emphasize the usefulness of computed tomography in these cases. Material and method: sixty-nine cases of pediatric patients with blunt abdominal trauma seen from from January 2001 to June 2004 at the level I trauma center were retrospectively studied. Forty-four of these patients were submitted to nonoperative treatment and the clinical follow-up was performed by computerized tomography. All patients had been diagnosed with splenic injury by computerized tomography.Results: the causes of the injuries were motor vehicle accident in 12 (27.2%) patients, bicycle accident in nine (20.4%) patients, and falls in 23 (52.2%) patients. Two (3.7%) patients died from associated injuries. The mean duration of hospital stay was six days. The mean age of the patients was nine years. Conclusion: conservative treatment for blunt splenic trauma is performed with the aim of reducing costs and risks for the patients, and computerized tomography should be routinely used. No posterior complications were observed in this approach. (author)

  14. Impact of electrocardiogram-gated multi-slice computed tomography-based aortic annular measurement in the evaluation of paravalvular leakage following transcatheter aortic valve replacement: the efficacy of the OverSized AortiC Annular ratio (OSACA ratio) in TAVR.

    Science.gov (United States)

    Maeda, Koichi; Kuratani, Toru; Torikai, Kei; Shimamura, Kazuo; Mizote, Isamu; Ichibori, Yasuhiro; Takeda, Yasuharu; Daimon, Takashi; Nakatani, Satoshi; Nanto, Shinsuke; Sawa, Yoshiki

    2013-07-01

    Even mild paravalvular leakage (PVL) after transcatheter aortic valve replacement (TAVR) is associated with increased late mortality. Electrocardiogram-gated multi-slice computed tomography (MSCT) enables detailed aortic annulus assessment. We describe the impact of MSCT for PVL following TAVR. Congruence between the prosthesis and annulus diameters affects PVL; therefore, we calculated the OverSized AortiC Annular ratio (OSACA ratio) and OSACA (transesophageal echocardiography, TEE) ratio as prosthesis diameter/annulus diameter on MSCT or TEE, respectively, and compared their relationship with PVL ≤ trace following TAVR. Of 36 consecutive patients undergoing TAVR (Group A), the occurrence of PVL ≤ trace (33.3%) was significantly related to the OSACA ratio (p = 0.00020). In receiver-operating characteristics analysis, the cutoff value of 1.03 for the OSACA ratio had the highest sum of sensitivity (75.0%) and specificity (91.7%; AUC = 0.87) with significantly higher discriminatory performance for PVL as compared to the OSACA (TEE) ratio (AUC = 0.69, p = 0.028). In nine consecutive patients (Group B) undergoing TAVR based on guidelines formulated from our experience with Group A, PVL ≤ trace was significantly more frequent (88.9%) than that in Group A (p = 0.0060). The OSACA ratio has a significantly higher discriminatory performance for PVL ≤ trace than the OSACA (TEE) ratio, and aortic annular measurement from MSCT is more accurate than that from TEE. © 2013 Wiley Periodicals, Inc.

  15. Cerenkov luminescence tomography based on preconditioning orthogonal matching pursuit

    Science.gov (United States)

    Liu, Haixiao; Hu, Zhenhua; Wang, Kun; Tian, Jie; Yang, Xin

    2015-03-01

    Cerenkov luminescence imaging (CLI) is a novel optical imaging method and has been proved to be a potential substitute of the traditional radionuclide imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This imaging method inherits the high sensitivity of nuclear medicine and low cost of optical molecular imaging. To obtain the depth information of the radioactive isotope, Cerenkov luminescence tomography (CLT) is established and the 3D distribution of the isotope is reconstructed. However, because of the strong absorption and scatter, the reconstruction of the CLT sources is always converted to an ill-posed linear system which is hard to be solved. In this work, the sparse nature of the light source was taken into account and the preconditioning orthogonal matching pursuit (POMP) method was established to effectively reduce the ill-posedness and obtain better reconstruction accuracy. To prove the accuracy and speed of this algorithm, a heterogeneous numerical phantom experiment and an in vivo mouse experiment were conducted. Both the simulation result and the mouse experiment showed that our reconstruction method can provide more accurate reconstruction result compared with the traditional Tikhonov regularization method and the ordinary orthogonal matching pursuit (OMP) method. Our reconstruction method will provide technical support for the biological application for Cerenkov luminescence.

  16. Computed tomography and nonoperative treatment for blunt abdominal trauma

    International Nuclear Information System (INIS)

    Watanabe, Shinsuke; Ishi, Takashi; Kamachi, Masahiro; Takahashi, Toshio.

    1990-01-01

    Studies were undertaken to determine if computed tomography (CT) could reliably assist physical examination in the initial assessment of blunt abdominal trauma, and also to examine how various abdominal injuries were managed with the guidance of CT. A total of 255 patients underwent emergency abdominal CT following blunt abdominal trauma over a period of seven years. One hundred and fifty two patients had abnormal CT scans, including 58 hepatic, 36 renal, 25 splenic and 9 pancreatic injuries as well as 67 patients with intra-abdominal hemorrhage and 21 patients with free abdominal air. A comparative study on the detection of pneumoperitoneum revealed CT to be far superior to plain radiography. One hundred and three patients had normal CT scans, all of whom were managed nonoperatively, except for three false-negative cases and two nontherapeutic cases. The patients with injury to the parenchymal organs were given nonoperative treatment if they had stable vital signs and no evidence of associated injuries demanding immediate surgery and the majority of these patients were managed well nonoperatively. CT was thus found to be a useful adjunct in the management of victims of blunt abdominal trauma, since in a rapid and noninvasive fashion, CT accurately defined the extent of parenchymal organ injury and also disclosed any other abdominal injuries. (author)

  17. Computed tomography and nonoperative treatment for blunt abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Shinsuke; Ishi, Takashi; Kamachi, Masahiro [Saiseikai Shiga Hospital, Shiga (Japan); Takahashi, Toshio

    1990-01-01

    Studies were undertaken to determine if computed tomography (CT) could reliably assist physical examination in the initial assessment of blunt abdominal trauma, and also to examine how various abdominal injuries were managed with the guidance of CT. A total of 255 patients underwent emergency abdominal CT following blunt abdominal trauma over a period of seven years. One hundred and fifty two patients had abnormal CT scans, including 58 hepatic, 36 renal, 25 splenic and 9 pancreatic injuries as well as 67 patients with intra-abdominal hemorrhage and 21 patients with free abdominal air. A comparative study on the detection of pneumoperitoneum revealed CT to be far superior to plain radiography. One hundred and three patients had normal CT scans, all of whom were managed nonoperatively, except for three false-negative cases and two nontherapeutic cases. The patients with injury to the parenchymal organs were given nonoperative treatment if they had stable vital signs and no evidence of associated injuries demanding immediate surgery and the majority of these patients were managed well nonoperatively. CT was thus found to be a useful adjunct in the management of victims of blunt abdominal trauma, since in a rapid and noninvasive fashion, CT accurately defined the extent of parenchymal organ injury and also disclosed any other abdominal injuries. (author).

  18. Principle of diffraction enhanced imaging (DEI) and computed tomography based on DEI method

    International Nuclear Information System (INIS)

    Zhu Peiping; Huang Wanxia; Yuan Qingxi; Wang Junyue; Zheng Xin; Shu Hang; Chen Bo; Liu Yijin; Li Enrong; Wu Ziyu; Yu Jian

    2006-01-01

    In the first part of this article a more general DEI equation was derived using simple concepts. Not only does the new DEI equation explain all the problems that can be done by the DEI equation proposed by Chapman, but also explains the problem that can not be explained with the old DEI equation, such as the noise background caused by the small angle scattering reflected by the analyzer. In the second part, a DEI-PI-CT formula has been proposed and the contour contrast caused by the extinction of refraction beam has been qualitatively explained, and then based on the work of Ando's group two formulae of refraction CT with DEI method has been proposed. Combining one refraction CT formula proposed by Dilmanian with the two refraction CT formulae proposed by us, the whole framework of CT algorithm can be made to reconstruct three components of the gradient of refractive index. (authors)

  19. Evaluation of thallium-201 myocardial emission computed tomography based on a comparison with postmortem findings

    International Nuclear Information System (INIS)

    Nagashima, Jun-ichi; Yamada, Hideo; Ohkawa, Shin-ichiro; Yonamine, Shigemichi; Nishino, Hideo; Yamagata, Atsushi; Suzuki, Yasuko; Tanno, Munehiko; Chiba, Kazuo

    1986-01-01

    The correlative study of myocardial perfusion assessed by 201 Tl myocardial ECT with the pathological finding of the heart was performed in 10 autopsied cases with mean age of 77 years old (range: 60 - 90 y). In 6 cases with myocardial infarction (MI) 7 perfusion defects were observed, that was, 3 in anteroseptal wall, 1 in anterolateral wall and 3 in posterior wall on the images of SPECT. Seven MIs were also found in postmortem examination. Six MIs were observed at autopsy corresponding to perfusion defect on SPECT images. In one myocardial perfusion defect at inferoposterior portion on SPECT, a non-transmural MI was found at anteroseptum. In one case with valvular disease a false positive result was obtained at posterior wall where neither myocardial necrosis nor fibrosis was observed at autopsy. This case had aortic stenosis due to bicuspid aortic valve by autopsy. The ventricle was devided into 16 segments in each of 4 short axial images to evaluate extent of MI. SPECT for extent of MI showed sensitivity of 81.9 %, specificity of 96.0 % and diagnostic accuracy of 92.5 %. False negative segment was apt to be observed at the surrounding of non-transmural MI or basal half of left ventricle (LV) with transmural MI, while false positive segment was at posterior portion of basal half of LV. It was concluded that myocardial ECT was useful for evaluation of the site and extent of MI. (author)

  20. Optimizing a micro-computed tomography-based surrogate measurement of bone-implant contact.

    Science.gov (United States)

    Meagher, Matthew J; Parwani, Rachna N; Virdi, Amarjit S; Sumner, Dale R

    2018-03-01

    Histology and backscatter scanning electron microscopy (bSEM) are the current gold standard methods for quantifying bone-implant contact (BIC), but are inherently destructive. Microcomputed tomography (μCT) is a non-destructive alternative, but attempts to validate μCT-based assessment of BIC in animal models have produced conflicting results. We previously showed in a rat model using a 1.5 mm diameter titanium implant that the extent of the metal-induced artefact precluded accurate measurement of bone sufficiently close to the interface to assess BIC. Recently introduced commercial laboratory μCT scanners have smaller voxels and improved imaging capabilities, possibly overcoming this limitation. The goals of the present study were to establish an approach for optimizing μCT imaging parameters and to validate μCT-based assessment of BIC. In an empirical parametric study using a 1.5 mm diameter titanium implant, we determined 90 kVp, 88 µA, 1.5 μm isotropic voxel size, 1600 projections/180°, and 750 ms integration time to be optimal. Using specimens from an in vivo rat experiment, we found significant correlations between bSEM and μCT for BIC with the manufacturer's automated analysis routine (r = 0.716, p = 0.003) or a line-intercept method (r = 0.797, p = 0.010). Thus, this newer generation scanner's improved imaging capability reduced the extent of the metal-induced artefact zone enough to permit assessment of BIC. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:979-986, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  1. Virtual Reality versus Computer-Aided Exposure Treatments for Fear of Flying

    Science.gov (United States)

    Tortella-Feliu, Miquel; Botella, Cristina; Llabres, Jordi; Breton-Lopez, Juana Maria; del Amo, Antonio Riera; Banos, Rosa M.; Gelabert, Joan M.

    2011-01-01

    Evidence is growing that two modalities of computer-based exposure therapies--virtual reality and computer-aided psychotherapy--are effective in treating anxiety disorders, including fear of flying. However, they have not yet been directly compared. The aim of this study was to analyze the efficacy of three computer-based exposure treatments for…

  2. Heat Transfer treatment in computer codes for safety analysis

    International Nuclear Information System (INIS)

    Jerele, A.; Gregoric, M.

    1984-01-01

    Increased number of operating nuclear power plants has stressed importance of nuclear safety evaluation. For this reason, accordingly to regulatory commission request, safety analyses with computer codes are preformed. In this paper part of this thermohydraulic models dealing with wall-to-fluid heat transfer correlations in computer codes TRAC=PF1, RELAP4/MOD5, RELAP5/MOD1 and COBRA-IV is discussed. (author)

  3. COMPARATIVE STUDY OF TERTIARY WASTEWATER TREATMENT BY COMPUTER SIMULATION

    OpenAIRE

    Stefania Iordache; Nicolae Petrescu; Cornel Ianache

    2010-01-01

    The aim of this work is to asses conditions for implementation of a Biological Nutrient Removal (BNR) process in theWastewater Treatment Plant (WWTP) of Moreni city (Romania). In order to meet the more increased environmentalregulations, the wastewater treatment plant that was studied, must update the actual treatment process and have tomodernize it. A comparative study was undertaken of the quality of effluents that could be obtained by implementationof biological nutrient removal process li...

  4. A computer-controlled conformal radiotherapy system. III: graphical simulation and monitoring of treatment delivery

    International Nuclear Information System (INIS)

    Kessler, Marc L.; McShan, Daniel L.; Fraass, Benedick A.

    1995-01-01

    Purpose: Safe and efficient delivery of radiotherapy using computer-controlled machines requires new procedures to design and verify the actual delivery of these treatments. Graphical simulation and monitoring techniques for treatment delivery have been developed for this purpose. Methods and Materials: A graphics-based simulator of the treatment machine and a set of procedures for creating and manipulating treatment delivery scripts are used to simulate machine motions, detect collisions, and monitor machine positions during treatment. The treatment delivery simulator is composed of four components: a three-dimensional dynamic model of the treatment machine; a motion simulation and collision detection algorithm, user-interface widgets that mimic the treatment machine's control and readout devices; and an icon-based interface for creating and manipulating treatment delivery scripts. These components are used in a stand-alone fashion for interactive treatment delivery planning and integrated with a machine control system for treatment implementation and monitoring. Results: A graphics-based treatment delivery simulator and a set of procedures for planning and monitoring computer-controlled treatment delivery have been developed and implemented as part of a comprehensive computer-controlled conformal radiotherapy system. To date, these techniques have been used to design and help monitor computer-controlled treatments on a radiotherapy machine for more than 200 patients. Examples using these techniques for treatment delivery planning and on-line monitoring of machine motions during therapy are described. Conclusion: A system that provides interactive graphics-based tools for defining the sequence of machine motions, simulating treatment delivery including collision detection, and presenting the therapists with continual visual feedback from the treatment machine has been successfully implemented for routine clinical use as part of an overall system for computer

  5. Computed tomography contrast media extravasation: treatment algorithm and immediate treatment by squeezing with multiple slit incisions.

    Science.gov (United States)

    Kim, Sue Min; Cook, Kyung Hoon; Lee, Il Jae; Park, Dong Ha; Park, Myong Chul

    2017-04-01

    In our hospital, an adverse event reporting system was initiated that alerts the plastic surgery department immediately after suspecting contrast media extravasation injury. This system is particularly important for a large volume of extravasation during power injector use. Between March 2011 and May 2015, a retrospective chart review was performed on all patients experiencing contrast media extravasation while being treated at our hospital. Immediate treatment by squeezing with multiple slit incisions was conducted for a portion of these patients. Eighty cases of extravasation were reported from approximately 218 000 computed tomography scans. The expected extravasation volume was larger than 50 ml, or severe pressure was felt on the affected limb in 23 patients. They were treated with multiple slit incisions followed by squeezing. Oedema of the affected limb disappeared after 1-2 hours after treatment, and the skin incisions healed within a week. We propose a set of guidelines for the initial management of contrast media extravasation injuries for a timely intervention. For large-volume extravasation cases, immediate management with multiple slit incisions is safe and effective in reducing the swelling quickly, preventing patient discomfort and decreasing skin and soft tissue problems. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  6. 3-D conformal radiation therapy - Part II: Computer-controlled 3-D treatment delivery

    International Nuclear Information System (INIS)

    Benedick, A.

    1997-01-01

    Purpose/Objective: This course will describe the use of computer-controlled treatment delivery techniques for treatment of patients with sophisticated conformal therapy. In particular, research and implementation issues related to clinical use of computer-controlled conformal radiation therapy (CCRT) techniques will be discussed. The possible/potential advantages of CCRT techniques will be highlighted using results from clinical 3-D planning studies. Materials and Methods: In recent years, 3-D treatment planning has been used to develop and implement 3-D conformal therapy treatment techniques, and studies based on these conformal treatments have begun to show the promise of conformal therapy. This work has been followed by the development of commercially-available multileaf collimator and computer control systems for treatment machines. Using these (and other) CCRT devices, various centers are beginning to clinically use complex computer-controlled treatments. Both research and clinical CCRT treatment techniques will be discussed in this presentation. General concepts and requirements for CCRT will be mentioned. Developmental and clinical experience with CCRT techniques from a number of centers will be utilized. Results: Treatment planning, treatment preparation and treatment delivery must be approached in an integrated fashion in order to clinically implement CCRT treatment techniques, and the entire process will be discussed. Various CCRT treatment methodologies will be reviewed from operational, dosimetric, and technical points of view. The discussion will concentrate on CCRT techniques which are likely to see rather wide dissemination over the next several years, including particularly the use of multileaf collimators (MLC), dynamic and segmental conformal therapy, conformal field shaping, and other related techniques. More advanced CCRT techniques, such as the use of individualized intensity modulation of beams or segments, and the use of computer

  7. [Clinical characteristics of computer game and internet addiction in persons seeking treatment in an outpatient clinic for computer game addiction].

    Science.gov (United States)

    Beutel, Manfred E; Hoch, Christina; Wölfling, Klaus; Müller, Kai W

    2011-01-01

    Since March 2008 we have offered outpatient treatment for computer game and internet addiction. This article presents the assessment and clinical characterization of the first cohort of one year. The reasons for seeking help (phone consultations, N=346) as well as sociodemographic and psychometric characteristics (N=131) (assessment of computer game addiction; SCL-90R) are presented. Consultation was initiated mainly by relatives--mostly the mothers (86%); 48% report achievement failure and social isolation, lack of control (38%) and conflicts within the family (33%). Two-thirds of the mainly male (96%) patients (N=131) with an average age of 22 (range 13-47) years met the criteria for pathological computer gaming, characterized by an excessive number of hours and preoccupation with gaming, high distress, and unemployment. Symptoms resemble those of other addiction disorders. The consequences for disorder-specific treatment concepts and research are discussed.

  8. Tomography based determination of permeability, Dupuit-Forchheimer coefficient, and interfacial heat transfer coefficient in reticulate porous ceramics

    International Nuclear Information System (INIS)

    Petrasch, Joerg; Meier, Fabian; Friess, Hansmartin; Steinfeld, Aldo

    2008-01-01

    A computer tomography based methodology is applied to determine the transport properties of fluid flow across porous media. A 3D digital representation of a 10-ppi reticulate porous ceramic (RPC) sample was generated by X-ray tomographic scans. Structural properties such as the porosity, specific interfacial surface area, pore-size distribution, mean survival time, two-point correlation function s 2 , and local geometry distribution of the RPC sample are directly extracted from the tomographic data. Reference solutions of the fluid flow governing equations are obtained for Re = 0.2-200 by applying finite volume direct pore-level numerical simulation (DPLS) using unstructured, body-fitted, tetrahedral mesh discretization. The permeability and the Dupuit-Forchheimer coefficient are determined from the reference solutions by DPLS, and compared to the values predicted by selected porous media flow models, namely: conduit-flow, hydraulic radius theory, drag models, mean survival time bound, s 2 -bound, fibrous bed correlations, and local porosity theory-based models. DPLS is further employed to determine the interfacial heat transfer coefficient and to derive a corresponding Nu-correlation, which is compared to empirical correlations

  9. 3D Computer aided treatment planning in endodontics

    NARCIS (Netherlands)

    van der Meer, Wicher J.; Vissink, Arjan; Ng, Yuan Ling; Gulabivala, Kishor

    Objectives: Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems

  10. Quality of data computational models and telemedicine treatment effects

    NARCIS (Netherlands)

    Larburu Rubio, Nekane; Widya, I.A.; Bults, Richard G.A.; Hermens, Hermanus J.

    2014-01-01

    Clinical decision-support functions of telemedicine systems use patient's monitored clinical data to support treatment of outpatients. However, the quality of monitored clinical data may vary due to performance variations of technological resources inside a deployed telemedicine system. This paper

  11. Overview and outlook on muon survey tomography based on micromegas detectors for unreachable sites technology

    Directory of Open Access Journals (Sweden)

    Roche I. Lázaro

    2016-01-01

    Full Text Available The present document describes the functioning principles of the Muon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology and its distinguishing features from other Micromegas-like detectors. Additionally, it addresses the challenges found while operating the first generation and the resulting improvements. Currently, the project Temporal Tomography of the Densitometry by the Measurement of Muons is focused on obtaining a reliable pulse from the micromesh, associated to the passing of a muon, in order to trigger the acquisition and operate in standalone mode. An outlook of the future steps of the project is provided as well.

  12. Computed tomography in the treatment of cervical spinal cord tumors

    International Nuclear Information System (INIS)

    Shin, Hideo

    1984-01-01

    Computed tomography (CT) of the cervical and thoracic spinal column was carried out in 12 patients of spinal cord tumor. There were 6 schwannomas, 2 metastatic tumors and other 4 cases of different tumors, which were studied by either a General Electric CT/T or a Toshiba TCT 60 Type A scanner. In all patients, CT-examination followed conventional spinal X-ray studies. The usefulness of the plain spinal CT (PCT: CT without any contrast enhancement neither intravenously nor intrathecally) was to detect subtle bony changes as well as paraspinal soft tissue abnormalities, although it was hard to distinguish the spinal cord by PCT. Metrizamide CT myelography (CTM: CT with intrathecal instillation of metrizamide) was indispensable to identify the intracanalicular architecture. It provided the clue to determine the site and the size of tumor, and it was also useful after surgical procedure. CTM with intravenous contrast enhancement (CTM-CE) together with CTM distinguished the spinal tumor from the spinal cord very well, particularly in the cases of schwannoma. The author supports significant reliability of PCT, CTM and CTM-CE in identifying the presence, the extension and the bony involvement of spinal cord tumors. (author)

  13. Computed tomographic findings in dogs with head trauma and development of a novel prognostic computed tomography-based scoring system.

    Science.gov (United States)

    Chai, Orit; Peery, Dana; Bdolah-Abram, Tali; Moscovich, Efrat; Kelmer, Efrat; Klainbart, Sigal; Milgram, Joshua; Shamir, Merav H

    2017-09-01

    OBJECTIVE To characterize CT findings and outcomes in dogs with head trauma and design a prognostic scale. ANIMALS 27 dogs admitted to the Koret School Veterinary Teaching Hospital within 72 hours after traumatic head injury that underwent CT imaging of the head. PROCEDURES Data were extracted from medical records regarding dog signalment, history, physical and neurologic examination findings, and modified Glasgow coma scale scores. All CT images were retrospectively evaluated by a radiologist unaware of dog status. Short-term (10 days after trauma) and long-term (≥ 6 months after trauma) outcomes were determined, and CT findings and other variables were analyzed for associations with outcome. A prognostic CT-based scale was developed on the basis of the results. RESULTS Cranial vault fractures, parenchymal abnormalities, or both were identified via CT in 24 of 27 (89%) dogs. Three (11%) dogs had only facial bone fractures. Intracranial hemorrhage was identified in 16 (59%) dogs, cranial vault fractures in 15 (56%), midline shift in 14 (52%), lateral ventricle asymmetry in 12 (44%), and hydrocephalus in 7 (26%). Hemorrhage and ventricular asymmetry were significantly and negatively associated with short- and long-term survival, respectively. The developed 7-point prognostic scale included points for hemorrhage, midline shift or lateral ventricle asymmetry, cranial vault fracture, and depressed fracture (1 point each) and infratentorial lesion (3 points). CONCLUSIONS AND CLINICAL RELEVANCE The findings reported here may assist in determining prognoses for other dogs with head trauma. The developed scale may be useful for outcome assessment of dogs with head trauma; however, it must be validated before clinical application.

  14. Pathological fracture prediction in patients with metastatic lesions can be improved with quantitative computed tomography based computer models

    NARCIS (Netherlands)

    Tanck, Esther; van Aken, Jantien B.; van der Linden, Yvette M.; Schreuder, H.W. Bart; Binkowski, Marcin; Huizenga, Henk; Verdonschot, Nico

    2009-01-01

    Purpose: In clinical practice, there is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. The methods that are currently used to estimate fracture risk are dissatisfying, hence affecting the quality of life of patients with a limited life expectancy.

  15. Computer-Based Script Training for Aphasia: Emerging Themes from Post-Treatment Interviews

    Science.gov (United States)

    Cherney, Leora R.; Halper, Anita S.; Kaye, Rosalind C.

    2011-01-01

    This study presents results of post-treatment interviews following computer-based script training for persons with chronic aphasia. Each of the 23 participants received 9 weeks of AphasiaScripts training. Post-treatment interviews were conducted with the person with aphasia and/or a significant other person. The 23 interviews yielded 584 coded…

  16. The value of computed tomography (CT) in the treatment of lung cancer

    International Nuclear Information System (INIS)

    Striggaris, K.; Gouliamos, A.; Garmatis, C.; Kaklamanis, N.; Vlahos, L.; Pontifex, G.

    1982-01-01

    The extensive recent literature on computed tomography (CT) includes several reports demonstrating the usefulness of body scanners in radiotherapy treatment planning. This followed earlier experience indicating the potential application of the technique in chest disease. The fast scan-times, possible with newer CT systems, eliminate motion degradation and provide accurate localization of thoracic tumors. This paper reports the authors' experience with CT in treatment planning of 38 patients with bronchogenic carcinoma after pretherapy evaluation by CT. They conclude that the availability of CT-scan data helps to define accurately the target volume and provides the information needed for treatment planning computers in order to estimate the desired dose. (Auth.)

  17. Study and establishment of a computer program for radiotherapy treatment planning development

    International Nuclear Information System (INIS)

    Djennaoui, N.

    1987-02-01

    The modern radiotherapy requires the use of computers. In addition to their accuracy, computers involve an appreciable saving of time in the calculation of isodoses, permitting us to change several times a technique in order to choose the best dose distribution for each case of tumor. The aim of this work was to set a computer program calculating a suitable dose distribution for a given treatment. The algorithm of calculation of the depth dose used in our program permits us to calculate the dose distribution for all photon energies used in radiotherapy, whatever are the energy and modification of the field by the use of wedge filters or bolus [fr

  18. Use of a radiation therapy treatment planning computer in a hospital health physics program

    International Nuclear Information System (INIS)

    Addison, S.J.

    1984-01-01

    An onsite treatment planning computer has become state of the art in the care of radiation therapy patients, but in most installations the computer is used for therapy planning a diminutive amount of the day. At St. Mary's Hospital, arrangements have been negotiated for part time use of the treatment planning computer for health physics purposes. Computerized Medical Systems, Inc. (CMS) produces the Modulex radiotherapy planning system which is programmed in MUMPS, a user oriented language specially adapted for handling text string information. St. Mary's Hospital's CMS computer has currently been programmed to assist in data collection and write-up of diagnostic x-ray surveys, meter calibrations, and wipe/leak tests. The computer is setup to provide timely reminders of tests and surveys, and billing for consultation work. Programs are currently being developed for radionuclide inventories. Use of a therapy planning computer for health physics purposes can enhance the radiation safety program and provide additional grounds for the acquisition of such a computer system

  19. Computer vision syndrome: a review of ocular causes and potential treatments.

    Science.gov (United States)

    Rosenfield, Mark

    2011-09-01

    Computer vision syndrome (CVS) is the combination of eye and vision problems associated with the use of computers. In modern western society the use of computers for both vocational and avocational activities is almost universal. However, CVS may have a significant impact not only on visual comfort but also occupational productivity since between 64% and 90% of computer users experience visual symptoms which may include eyestrain, headaches, ocular discomfort, dry eye, diplopia and blurred vision either at near or when looking into the distance after prolonged computer use. This paper reviews the principal ocular causes for this condition, namely oculomotor anomalies and dry eye. Accommodation and vergence responses to electronic screens appear to be similar to those found when viewing printed materials, whereas the prevalence of dry eye symptoms is greater during computer operation. The latter is probably due to a decrease in blink rate and blink amplitude, as well as increased corneal exposure resulting from the monitor frequently being positioned in primary gaze. However, the efficacy of proposed treatments to reduce symptoms of CVS is unproven. A better understanding of the physiology underlying CVS is critical to allow more accurate diagnosis and treatment. This will enable practitioners to optimize visual comfort and efficiency during computer operation. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  20. Use of Computer and Mobile Technologies in the Treatment of Depression.

    Science.gov (United States)

    Callan, Judith A; Wright, Jesse; Siegle, Greg J; Howland, Robert H; Kepler, Britney B

    2017-06-01

    Major depression (MDD) is a common and disabling disorder. Research has shown that most people with MDD receive either no treatment or inadequate treatment. Computer and mobile technologies may offer solutions for the delivery of therapies to untreated or inadequately treated individuals with MDD. The authors review currently available technologies and research aimed at relieving symptoms of MDD. These technologies include computer-assisted cognitive-behavior therapy (CCBT), web-based self-help, Internet self-help support groups, mobile psychotherapeutic interventions (i.e., mobile applications or apps), technology enhanced exercise, and biosensing technology. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Computed tomography and treatment of chronic temporomandibular joint arthritis in a sheep

    International Nuclear Information System (INIS)

    Warmerdam, E.P.L.; Weeren, P.R. van

    1996-01-01

    Diagnostic imaging and treatment of destructive right temporomandibular joint (TMJ) arthritis in a sheep are discussed. Computed tomography (CT) appears to be an attractive technique for imaging TMJ lesions in sheep. Surgical curettage of a deformed TMJ can result in functional recovery

  2. Computer-Based Intepretation of the Marital Satisfaction Inventory: Use in Treatment Planning.

    Science.gov (United States)

    Snyder, Douglas K.; And Others

    1988-01-01

    Describes computer-based interpretive system for Marital Satisfaction Inventory (MSI) and application in initial phases of clinical assessment and treatment planning. Provides case study. Compares clinical findings at intake with MSI profiles for one couple obtained at termination and follow-up. Considers strengths and limitations of self-report…

  3. The outcome of root-canal treatments assessed by cone-beam computed tomography

    NARCIS (Netherlands)

    Liang, Y.H.

    2013-01-01

    In this thesis, in-vivo and ex-vivo methods were utilized to assess the outcome of root canal treatments determined by cone-beam computed tomography (CBCT) and the reliability of the CBCT-findings. CBCT provided useful and reliable information leading to a better understanding of the outcome and

  4. Role of Cone Beam Computed Tomography in Diagnosis and Treatment Planning in Dentistry: An Update.

    Science.gov (United States)

    Shukla, Sagrika; Chug, Ashi; Afrashtehfar, Kelvin I

    2017-11-01

    Accurate diagnosis and treatment planning are the backbone of any medical therapy; for this reason, cone beam computed tomography (CBCT) was introduced and has been widely used. CBCT technology provides a three-dimensional image viewing, enabling exact location and extent of lesions or any anatomical region. For the very same reason, CBCT can not only be used for surgical fields but also for fields such as endodontics, prosthodontics, and orthodontics for appropriate treatment planning and effective dental care. The aim and clinical significance of this review are to update dental clinicians on the CBCT applications in each dental specialty for an appropriate diagnosis and more predictable treatment.

  5. SU-E-T-222: Computational Optimization of Monte Carlo Simulation On 4D Treatment Planning Using the Cloud Computing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Chow, J [Princess Margaret Cancer Center, Toronto, ON (Canada)

    2015-06-15

    Purpose: This study evaluated the efficiency of 4D lung radiation treatment planning using Monte Carlo simulation on the cloud. The EGSnrc Monte Carlo code was used in dose calculation on the 4D-CT image set. Methods: 4D lung radiation treatment plan was created by the DOSCTP linked to the cloud, based on the Amazon elastic compute cloud platform. Dose calculation was carried out by Monte Carlo simulation on the 4D-CT image set on the cloud, and results were sent to the FFD4D image deformation program for dose reconstruction. The dependence of computing time for treatment plan on the number of compute node was optimized with variations of the number of CT image set in the breathing cycle and dose reconstruction time of the FFD4D. Results: It is found that the dependence of computing time on the number of compute node was affected by the diminishing return of the number of node used in Monte Carlo simulation. Moreover, the performance of the 4D treatment planning could be optimized by using smaller than 10 compute nodes on the cloud. The effects of the number of image set and dose reconstruction time on the dependence of computing time on the number of node were not significant, as more than 15 compute nodes were used in Monte Carlo simulations. Conclusion: The issue of long computing time in 4D treatment plan, requiring Monte Carlo dose calculations in all CT image sets in the breathing cycle, can be solved using the cloud computing technology. It is concluded that the optimized number of compute node selected in simulation should be between 5 and 15, as the dependence of computing time on the number of node is significant.

  6. SU-E-T-222: Computational Optimization of Monte Carlo Simulation On 4D Treatment Planning Using the Cloud Computing Technology

    International Nuclear Information System (INIS)

    Chow, J

    2015-01-01

    Purpose: This study evaluated the efficiency of 4D lung radiation treatment planning using Monte Carlo simulation on the cloud. The EGSnrc Monte Carlo code was used in dose calculation on the 4D-CT image set. Methods: 4D lung radiation treatment plan was created by the DOSCTP linked to the cloud, based on the Amazon elastic compute cloud platform. Dose calculation was carried out by Monte Carlo simulation on the 4D-CT image set on the cloud, and results were sent to the FFD4D image deformation program for dose reconstruction. The dependence of computing time for treatment plan on the number of compute node was optimized with variations of the number of CT image set in the breathing cycle and dose reconstruction time of the FFD4D. Results: It is found that the dependence of computing time on the number of compute node was affected by the diminishing return of the number of node used in Monte Carlo simulation. Moreover, the performance of the 4D treatment planning could be optimized by using smaller than 10 compute nodes on the cloud. The effects of the number of image set and dose reconstruction time on the dependence of computing time on the number of node were not significant, as more than 15 compute nodes were used in Monte Carlo simulations. Conclusion: The issue of long computing time in 4D treatment plan, requiring Monte Carlo dose calculations in all CT image sets in the breathing cycle, can be solved using the cloud computing technology. It is concluded that the optimized number of compute node selected in simulation should be between 5 and 15, as the dependence of computing time on the number of node is significant

  7. Diagnosis and treatment of postoperative intraperitoneal abscess using ultrasonography and abdominal computed tomography

    International Nuclear Information System (INIS)

    Kamachi, Hisashi; Kumashiro, Ryunosuke; Maekawa, Takafumi; Saku, Haruhisa; Naitoh, Hideaki; Inutsuka, Sadamitsu; Higashi, Yoshitaka

    1988-01-01

    Ultrasonography and/or abdominal computed tomography revealed 9 patients with subphrenic abscesses derived from gastrointestinal surgery. Out of them 4 cases underwent conservative treatment is chosen with aggresive chemotherapy, but 5 were re-surgically treated including drainage of the intraperitonial abscess or repairing the leakage of the anastomosis. On the conservative treatment for the intraperitonial abscess, frequent monitoring with ultrasonography was very conventional for successful treatment. However, in the cases with severe leukocytosis, leakage of anastomosis or recurrent intraperitonial abscess, resurgical treatment will be required. Thus the monitoring with ultrasonography is quite usefull not only in the drainaging of the intraperitonial abscess, but also in the judgement of treatment whether conservetive or re-operative. (author)

  8. Treatment of a Four-Rooted Maxillary Second Molar Detected with Cone-Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Nahid Mohammadzade Akhlaghi

    2017-08-01

    Full Text Available The significance of clinician’s knowledge about root canal anatomy and its possible variations cannot be overlooked. In some cases, taking advantage of complementary imaging techniques can help achieve a perfect flawless endodontic treatment. This article reports endodontic management of a second maxillary molar that had an uncommon anatomy of the chamber floor. After obtaining a cone-beam computed tomography (CBCT image, the presence of a second palatal root was confirmed. All four roots were treated and patient’s symptoms were resolved.Keywords: Cone-Beam Computed Tomography; Root Canal Therapy; Tooth Root

  9. QA Issues for Computer-Controlled Treatment Delivery: This Is Not Your Old R/V System Any More!

    International Nuclear Information System (INIS)

    Fraass, Benedick A.

    2008-01-01

    State-of-the-art radiotherapy treatment delivery has changed dramatically during the past decade, moving from manual individual field setup and treatment to automated computer-controlled delivery of complex treatments, including intensity-modulated radiotherapy and other similarly complex delivery strategies. However, the quality assurance methods typically used to ensure treatment is performed precisely and correctly have not evolved in a similarly dramatic way. This paper reviews the old manual treatment process and use of record-and-verify systems, and describes differences with modern computer-controlled treatment delivery. The process and technology used for computer-controlled treatment delivery are analyzed in terms of potential (and actual) problems, as well as relevant published guidance on quality assurance. The potential for improved quality assurance for computer-controlled delivery is discussed

  10. A computational tool integrating host immunity with antibiotic dynamics to study tuberculosis treatment.

    Science.gov (United States)

    Pienaar, Elsje; Cilfone, Nicholas A; Lin, Philana Ling; Dartois, Véronique; Mattila, Joshua T; Butler, J Russell; Flynn, JoAnne L; Kirschner, Denise E; Linderman, Jennifer J

    2015-02-21

    While active tuberculosis (TB) is a treatable disease, many complex factors prevent its global elimination. Part of the difficulty in developing optimal therapies is the large design space of antibiotic doses, regimens and combinations. Computational models that capture the spatial and temporal dynamics of antibiotics at the site of infection can aid in reducing the design space of costly and time-consuming animal pre-clinical and human clinical trials. The site of infection in TB is the granuloma, a collection of immune cells and bacteria that form in the lung, and new data suggest that penetration of drugs throughout granulomas is problematic. Here we integrate our computational model of granuloma formation and function with models for plasma pharmacokinetics, lung tissue pharmacokinetics and pharmacodynamics for two first line anti-TB antibiotics. The integrated model is calibrated to animal data. We make four predictions. First, antibiotics are frequently below effective concentrations inside granulomas, leading to bacterial growth between doses and contributing to the long treatment periods required for TB. Second, antibiotic concentration gradients form within granulomas, with lower concentrations toward their centers. Third, during antibiotic treatment, bacterial subpopulations are similar for INH and RIF treatment: mostly intracellular with extracellular bacteria located in areas non-permissive for replication (hypoxic areas), presenting a slowly increasing target population over time. Finally, we find that on an individual granuloma basis, pre-treatment infection severity (including bacterial burden, host cell activation and host cell death) is predictive of treatment outcome. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. A computer-based anaglyphic system for the treatment of amblyopia

    Directory of Open Access Journals (Sweden)

    Rastegarpour A

    2011-09-01

    Full Text Available Ali Rastegarpour Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Purpose: Virtual reality (VR-based treatment has been introduced as a potential option for amblyopia management, presumably without involving the problems of occlusion and penalization, including variable and unsatisfactory outcomes, long duration of treatment, poor compliance, psychological impact, and complications. However, VR-based treatment is costly and not accessible for most children. This paper introduces a method that encompasses the advantages of VR-based treatment at a lower cost. Methods: The presented system consists of a pair of glasses with two color filters and software for use on a personal computer. The software is designed such that some active graphic components can only be seen by the amblyopic eye and are filtered out for the other eye. Some components would be seen by both to encourage fusion. The result is that the patient must use both eyes, and specifically the amblyopic eye, to play the games. Results: A prototype of the system, the ABG InSight, was found capable of successfully filtering out elements of a certain color and therefore, could prove to be a viable alternative to VR-based treatment for amblyopia. Conclusion: The anaglyphic system maintains most of the advantages of VR-based systems, but is less costly and highly accessible. It fulfills the means that VR-based systems are designed to achieve, and warrants further investigation. Keywords: amblyopia, computer-based, open source, virtual reality, color filters, 3-D

  12. [Treatment choice in dacryostenosis based on single-photon emission computed tomography and X-ray computed tomography findings].

    Science.gov (United States)

    At'kova, E L; Yartsev, V D; Tomashevskiy, I O; Krakhovetskiy, N N

    2016-01-01

    To develop surgical indications in dacryostenosis within the vertical portion of lacrimal pathways that would consider findings of single-photon emission computed tomography (SPECT) combined with X-ray computed tomography (CT). A total of 96 patients with isolated vertical-portion dacryostenosis (127 cases) were enrolled. The examination included collecting Munk's scores for epiphora, optical coherence tomography of the lower tear meniscus, lacrimal scintigraphy, and SPECT/CT. Group 1 (40 cases) was composed of patients with lacrimal obstruction on CT, group 2 (87 cases) - of those whose lacrimal pathways proved passable. There were also 3 patients (4 cases) from group 1, whose lacrimal pathways, despite being blocked on CT, were still passable on SPECT. Surgeries performed in group 1 were endoscopic endonasal dacryocystorhinostomy (DCR) (36 cases) and pathways recanalization with bicanalicular intubation and balloon dacryoplasty (DCP) (4 cases). In group 2, all patients (87 cases) underwent recanalization with bicanalicular intubation (supplemented with balloon DCP in 32 cases). Surgical results were evaluated 8-12 months after the treatment. In group 2, particular attention was paid to the concordance in locations of dacryostenosis provided by CT and SPECT scans. Favorable outcomes of endoscopic endonasal DCR were obtained in as many as 32 cases from group 1 (88.9%), while in 4 cases (12.1%) the condition relapsed. Of those patients whose stenosis was not complete on SPECT, 3 cases (75.0%) improved, 1 (25.0%) - relapsed. In group 2, favorable outcomes were obtained in 65 cases (74.7%), relapses were 22 (25.3%). A high concordance in stenosis locations by CT and SPECT was noted in 60 cases of those who improved (92.3%) and 3 cases of those who relapsed (13.6%). The value of information provided by SPECT/CT has proved high in patients with nasolacrimal duct stenosis or obstruction. A combined scan allows to establish causal relationships between anatomical changes

  13. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  14. HIV reservoirs and immune surveillance evasion cause the failure of structured treatment interruptions: a computational study.

    Directory of Open Access Journals (Sweden)

    Emiliano Mancini

    Full Text Available Continuous antiretroviral therapy is currently the most effective way to treat HIV infection. Unstructured interruptions are quite common due to side effects and toxicity, among others, and cannot be prevented. Several attempts to structure these interruptions failed due to an increased morbidity compared to continuous treatment. The cause of this failure is poorly understood and often attributed to drug resistance. Here we show that structured treatment interruptions would fail regardless of the emergence of drug resistance. Our computational model of the HIV infection dynamics in lymphoid tissue inside lymph nodes, demonstrates that HIV reservoirs and evasion from immune surveillance themselves are sufficient to cause the failure of structured interruptions. We validate our model with data from a clinical trial and show that it is possible to optimize the schedule of interruptions to perform as well as the continuous treatment in the absence of drug resistance. Our methodology enables studying the problem of treatment optimization without having impact on human beings. We anticipate that it is feasible to steer new clinical trials using computational models.

  15. Use of Monte Carlo computation in benchmarking radiotherapy treatment planning system algorithms

    International Nuclear Information System (INIS)

    Lewis, R.D.; Ryde, S.J.S.; Seaby, A.W.; Hancock, D.A.; Evans, C.J.

    2000-01-01

    Radiotherapy treatments are becoming more complex, often requiring the dose to be calculated in three dimensions and sometimes involving the application of non-coplanar beams. The ability of treatment planning systems to accurately calculate dose under a range of these and other irradiation conditions requires evaluation. Practical assessment of such arrangements can be problematical, especially when a heterogeneous medium is used. This work describes the use of Monte Carlo computation as a benchmarking tool to assess the dose distribution of external photon beam plans obtained in a simple heterogeneous phantom by several commercially available 3D and 2D treatment planning system algorithms. For comparison, practical measurements were undertaken using film dosimetry. The dose distributions were calculated for a variety of irradiation conditions designed to show the effects of surface obliquity, inhomogeneities and missing tissue above tangential beams. The results show maximum dose differences of 47% between some planning algorithms and film at a point 1 mm below a tangentially irradiated surface. Overall, the dose distribution obtained from film was most faithfully reproduced by the Monte Carlo N-Particle results illustrating the potential of Monte Carlo computation in evaluating treatment planning system algorithms. (author)

  16. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction CMS distributed computing system performed well during the 2011 start-up. The events in 2011 have more pile-up and are more complex than last year; this results in longer reconstruction times and harder events to simulate. Significant increases in computing capacity were delivered in April for all computing tiers, and the utilisation and load is close to the planning predictions. All computing centre tiers performed their expected functionalities. Heavy-Ion Programme The CMS Heavy-Ion Programme had a very strong showing at the Quark Matter conference. A large number of analyses were shown. The dedicated heavy-ion reconstruction facility at the Vanderbilt Tier-2 is still involved in some commissioning activities, but is available for processing and analysis. Facilities and Infrastructure Operations Facility and Infrastructure operations have been active with operations and several important deployment tasks. Facilities participated in the testing and deployment of WMAgent and WorkQueue+Request...

  17. COMPUTING

    CERN Multimedia

    P. McBride

    The Computing Project is preparing for a busy year where the primary emphasis of the project moves towards steady operations. Following the very successful completion of Computing Software and Analysis challenge, CSA06, last fall, we have reorganized and established four groups in computing area: Commissioning, User Support, Facility/Infrastructure Operations and Data Operations. These groups work closely together with groups from the Offline Project in planning for data processing and operations. Monte Carlo production has continued since CSA06, with about 30M events produced each month to be used for HLT studies and physics validation. Monte Carlo production will continue throughout the year in the preparation of large samples for physics and detector studies ramping to 50 M events/month for CSA07. Commissioning of the full CMS computing system is a major goal for 2007. Site monitoring is an important commissioning component and work is ongoing to devise CMS specific tests to be included in Service Availa...

  18. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview During the past three months activities were focused on data operations, testing and re-enforcing shift and operational procedures for data production and transfer, MC production and on user support. Planning of the computing resources in view of the new LHC calendar in ongoing. Two new task forces were created for supporting the integration work: Site Commissioning, which develops tools helping distributed sites to monitor job and data workflows, and Analysis Support, collecting the user experience and feedback during analysis activities and developing tools to increase efficiency. The development plan for DMWM for 2009/2011 was developed at the beginning of the year, based on the requirements from the Physics, Computing and Offline groups (see Offline section). The Computing management meeting at FermiLab on February 19th and 20th was an excellent opportunity discussing the impact and for addressing issues and solutions to the main challenges facing CMS computing. The lack of manpower is particul...

  19. Computer simulation games as an adjunct for treatment in male veterans with alcohol use disorder.

    Science.gov (United States)

    Verduin, Marcia L; LaRowe, Steven D; Myrick, Hugh; Cannon-Bowers, Jan; Bowers, Clint

    2013-03-01

    This study examined the impact of a computer simulation designed to provide the opportunity for individuals with alcohol use disorders (AUDs) to practice relapse prevention skills. Participants were 41 male veterans enrolled in an intensive outpatient substance abuse treatment program. Participants were randomly assigned to either view educational slides about treatment for AUD or play a simulation videogame for eight sessions within 12 weeks. Participants were assessed at a 4-week follow-up visit. Outcome measures included relapse rates as well as ratings on the Obsessive Compulsive Drinking Scale (OCDS) and a custom-designed relapse prevention self efficacy scale. While rates of relapse did not differ between groups, those who played the game showed overall reductions in ratings on the OCDS, as well as higher ratings of self-efficacy at week 8, suggesting that the videogame simulation may be a useful adjunct to AUD treatment. Published by Elsevier Inc.

  20. Apical root resorption due to orthodontic treatment detected by cone beam computed tomography.

    Science.gov (United States)

    Castro, Iury O; Alencar, Ana H G; Valladares-Neto, José; Estrela, Carlos

    2013-03-01

    To determine the frequency of apical root resorption (ARR) due to orthodontic treatment using cone beam computed tomography (CBCT) in a sample of 1256 roots from 30 patients. All patients had Class I malocclusion with crowding. Of the 30 patients evaluated, 11 were boys and 19 were girls; their mean age was 13 years (11 to 16 years). Orthodontic treatment followed the nonextraction treatment. CBCT images were obtained before and after orthodontic treatment, and ARR was determined using Axial Guided Navigation of CBCT images. All patients had ARR. No statistically significant association was found between resorption frequency, gender, and age. ARR was detected using CBCT in 46% of all roots that underwent orthodontic treatment. CBCT was effective for detecting in vivo even minimal degrees of ARR due to orthodontic treatment and allowed three-dimensional evaluation of dental roots and visualization of palatine roots of maxillary molars. The highest frequencies and the most significant ARR occurred in incisors and distal roots of first maxillary and mandibular molars.

  1. Computer-assisted planning and dosimetry for radiation treatment of head and neck cancer in Cameroon

    International Nuclear Information System (INIS)

    Yomi, J.; Ngniah, A.; Kingue, S.; Muna, W.F.T.; Durosinmi-Etti, F.A.

    1995-01-01

    This evaluation was part of a multicenter, multinational study sponsored by the International Agency for Atomic Energy (Vienna) to investigate a simple, reliable computer-assisted planning and dosimetry system for radiation treatment of head and neck cancers in developing countries. Over a 13-month period (April 1992-April 1993), 120 patients with histologically-proven head or neck cancer were included in the evaluation. In each patient, planning and dosimetry were done both manually and using the computer-assisted system. The manual and computerized systems were compared on the basis of accuracy of determination of the outer contour, target volume, and critical organs; volume inequality resolution; structure heterogeneity correction; selection of the number, angle, and size of beams; treatment time calculation; availability of dosimetry predictions; and duration and cost of the procedure. Results demonstrated that the computer-assisted procedure was superior over the manual procedure, despite less than optimal software. The accuracy provided by the completely computerized procedure is indispensable for Level II radiation therapy, which is particularly useful in tumors of the sensitive, complex structures in the head and neck. (authors). 7 refs., 3 tabs

  2. Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Guerra Liberal, Francisco D. C., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, Adriana Alexandre S., E-mail: meb12020@fe.up.pt, E-mail: adriana-tavares@msn.com; Tavares, João Manuel R. S., E-mail: tavares@fe.up.pt [Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465 (Portugal)

    2014-11-01

    Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ({sup 32}P), strontium-89 ({sup 89}Sr), yttrium-90 ({sup 90}Y ), tin-117 ({sup 117m}Sn), samarium-153 ({sup 153}Sm), holmium-166 ({sup 166}Ho), thulium-170 ({sup 170}Tm), lutetium-177 ({sup 177}Lu), rhenium-186 ({sup 186}Re), rhenium-188 ({sup 188}Re), and radium-223 ({sup 223}Ra). Results: {sup 223}Ra alpha particles, {sup 177}Lu beta minus particles, and {sup 170}Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by {sup 89}Sr and {sup 153}Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than {sup 177}Lu beta minus particles and {sup 223}Ra alpha particles. Conclusions: {sup 223}Ra and {sup 177}Lu hold the highest potential for palliative treatment of bone metastases of all

  3. Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

    International Nuclear Information System (INIS)

    Guerra Liberal, Francisco D. C.; Tavares, Adriana Alexandre S.; Tavares, João Manuel R. S.

    2014-01-01

    Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ( 32 P), strontium-89 ( 89 Sr), yttrium-90 ( 90 Y ), tin-117 ( 117m Sn), samarium-153 ( 153 Sm), holmium-166 ( 166 Ho), thulium-170 ( 170 Tm), lutetium-177 ( 177 Lu), rhenium-186 ( 186 Re), rhenium-188 ( 188 Re), and radium-223 ( 223 Ra). Results: 223 Ra alpha particles, 177 Lu beta minus particles, and 170 Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by 89 Sr and 153 Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than 177 Lu beta minus particles and 223 Ra alpha particles. Conclusions: 223 Ra and 177 Lu hold the highest potential for palliative treatment of bone metastases of all radioisotopes compared in this study. Data reported here may prompt future in vitro and in vivo

  4. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing activity had ramped down after the completion of the reprocessing of the 2012 data and parked data, but is increasing with new simulation samples for analysis and upgrade studies. Much of the Computing effort is currently involved in activities to improve the computing system in preparation for 2015. Operations Office Since the beginning of 2013, the Computing Operations team successfully re-processed the 2012 data in record time, not only by using opportunistic resources like the San Diego Supercomputer Center which was accessible, to re-process the primary datasets HTMHT and MultiJet in Run2012D much earlier than planned. The Heavy-Ion data-taking period was successfully concluded in February collecting almost 500 T. Figure 3: Number of events per month (data) In LS1, our emphasis is to increase efficiency and flexibility of the infrastructure and operation. Computing Operations is working on separating disk and tape at the Tier-1 sites and the full implementation of the xrootd federation ...

  5. Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

    Science.gov (United States)

    Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

    2016-03-01

    Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

  6. SU-C-206-03: Metal Artifact Reduction in X-Ray Computed Tomography Based On Local Anatomical Similarity

    International Nuclear Information System (INIS)

    Dong, X; Yang, X; Rosenfield, J; Elder, E; Dhabaan, A

    2016-01-01

    Purpose: Metal implants such as orthopedic hardware and dental fillings cause severe bright and dark streaking in reconstructed CT images. These artifacts decrease image contrast and degrade HU accuracy, leading to inaccuracies in target delineation and dose calculation. Additionally, such artifacts negatively impact patient set-up in image guided radiation therapy (IGRT). In this work, we propose a novel method for metal artifact reduction which utilizes the anatomical similarity between neighboring CT slices. Methods: Neighboring CT slices show similar anatomy. Based on this anatomical similarity, the proposed method replaces corrupted CT pixels with pixels from adjacent, artifact-free slices. A gamma map, which is the weighted summation of relative HU error and distance error, is calculated for each pixel in the artifact-corrupted CT image. The minimum value in each pixel’s gamma map is used to identify a pixel from the adjacent CT slice to replace the corresponding artifact-corrupted pixel. This replacement only occurs if the minimum value in a particular pixel’s gamma map is larger than a threshold. The proposed method was evaluated with clinical images. Results: Highly attenuating dental fillings and hip implants cause severe streaking artifacts on CT images. The proposed method eliminates the dark and bright streaking and improves the implant delineation and visibility. In particular, the image non-uniformity in the central region of interest was reduced from 1.88 and 1.01 to 0.28 and 0.35, respectively. Further, the mean CT HU error was reduced from 328 HU and 460 HU to 60 HU and 36 HU, respectively. Conclusions: The proposed metal artifact reduction method replaces corrupted image pixels with pixels from neighboring slices that are free of metal artifacts. This method proved capable of suppressing streaking artifacts, improving HU accuracy and image detectability.

  7. A virtual sinogram method to reduce dental metallic implant artefacts in computed tomography-based attenuation correction for PET

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Ay, Mohammad Reza; Ahmadian, Alireza; Zaidi, Habib

    Objective Attenuation correction of PET data requires accurate determination of the attenuation map (mu map), which represents the spatial distribution of linear attenuation coefficients of different tissues at 511 keV. The presence of high-density metallic dental filling material in head and neck

  8. Three-dimensional in vivo imaging of the murine liver: a micro-computed tomography-based anatomical study.

    Directory of Open Access Journals (Sweden)

    Teresa Fiebig

    Full Text Available Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.

  9. SU-C-206-03: Metal Artifact Reduction in X-Ray Computed Tomography Based On Local Anatomical Similarity

    Energy Technology Data Exchange (ETDEWEB)

    Dong, X; Yang, X; Rosenfield, J; Elder, E; Dhabaan, A [Emory University, Winship Cancer Institute, Atlanta, GA (United States)

    2016-06-15

    Purpose: Metal implants such as orthopedic hardware and dental fillings cause severe bright and dark streaking in reconstructed CT images. These artifacts decrease image contrast and degrade HU accuracy, leading to inaccuracies in target delineation and dose calculation. Additionally, such artifacts negatively impact patient set-up in image guided radiation therapy (IGRT). In this work, we propose a novel method for metal artifact reduction which utilizes the anatomical similarity between neighboring CT slices. Methods: Neighboring CT slices show similar anatomy. Based on this anatomical similarity, the proposed method replaces corrupted CT pixels with pixels from adjacent, artifact-free slices. A gamma map, which is the weighted summation of relative HU error and distance error, is calculated for each pixel in the artifact-corrupted CT image. The minimum value in each pixel’s gamma map is used to identify a pixel from the adjacent CT slice to replace the corresponding artifact-corrupted pixel. This replacement only occurs if the minimum value in a particular pixel’s gamma map is larger than a threshold. The proposed method was evaluated with clinical images. Results: Highly attenuating dental fillings and hip implants cause severe streaking artifacts on CT images. The proposed method eliminates the dark and bright streaking and improves the implant delineation and visibility. In particular, the image non-uniformity in the central region of interest was reduced from 1.88 and 1.01 to 0.28 and 0.35, respectively. Further, the mean CT HU error was reduced from 328 HU and 460 HU to 60 HU and 36 HU, respectively. Conclusions: The proposed metal artifact reduction method replaces corrupted image pixels with pixels from neighboring slices that are free of metal artifacts. This method proved capable of suppressing streaking artifacts, improving HU accuracy and image detectability.

  10. Computed tomographic findings and treatment of a bull with pituitary gland abscess.

    Science.gov (United States)

    Braun, Ueli; Malbon, Alexandra; Kochan, Manon; Riond, Barbara; Janett, Fredi; Iten, Cornelia; Dennler, Matthias

    2017-01-13

    In cattle, the prognosis of brain abscess is unfavourable and treatment is therefore not recommended. To the knowledge of the authors, there has been no report of successful treatment of a brain abscess in cattle.This report describes the clinical, computed tomographic and postmortem findings in a Holstein-Friesian bull with a hypophyseal abscess. The main clinical findings were generalised ataxia, ptyalism, prolapse of the tongue, dropped jaw, dysphagia, head tilt and unilateral ptosis. Cerebrospinal fluid evaluation revealed 2437 leukocytes/µl and severe pleocytosis. CT examination of the head showed a cavitary lesion consistent with an abscess in the hypophysis. Treatment consisted of gentamicin and flunixin meglumine for 3 days and amoxicillin for 40 days. The neurological signs resolved within 8 days of the start of treatment. The bull was slaughtered 11 months later because of infertility, and a postmortem examination was carried out. Histologically, a mild chronic non suppurative meningoencephalitis restricted to the ventral diencephalon was diagnosed. In addition, there was mild to moderate multifocal chronic lymphoplasmacytic hypophysitis with mild multifocal fibrosis. This case report stresses the significance of CT in confirming the clinical and laboratory diagnosis of central nervous system disorders in cattle and for localising brain lesions. Treatment of the brain abscess resulted, with respect to the central nervous disorder, in a successful outcome and was encouraging considering that most cases have an unfavourable prognosis.

  11. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  12. COMPUTING

    CERN Multimedia

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  13. Single photon emission computed tomography (SPECT of anxiety disorders before and after treatment with citalopram

    Directory of Open Access Journals (Sweden)

    Seedat Soraya

    2004-10-01

    Full Text Available Abstract Background Several studies have now examined the effects of selective serotonin reuptake inhibitor (SSRI treatment on brain function in a variety of anxiety disorders including obsessive-compulsive disorder (OCD, posttraumatic stress disorder (PTSD, and social anxiety disorder (social phobia (SAD. Regional changes in cerebral perfusion following SSRI treatment have been shown for all three disorders. The orbitofrontal cortex (OFC (OCD, caudate (OCD, medial pre-frontal/cingulate (OCD, SAD, PTSD, temporal (OCD, SAD, PTSD and, thalamic regions (OCD, SAD are some of those implicated. Some data also suggests that higher perfusion pre-treatment in the anterior cingulate (PTSD, OFC, caudate (OCD and antero-lateral temporal region (SAD predicts subsequent treatment response. This paper further examines the notion of overlap in the neurocircuitry of treatment and indeed treatment response across anxiety disorders with SSRI treatment. Methods Single photon emission computed tomography (SPECT using Tc-99 m HMPAO to assess brain perfusion was performed on subjects with OCD, PTSD, and SAD before and after 8 weeks (SAD and 12 weeks (OCD and PTSD treatment with the SSRI citalopram. Statistical parametric mapping (SPM was used to compare scans (pre- vs post-medication, and responders vs non-responders in the combined group of subjects. Results Citalopram treatment resulted in significant deactivation (p = 0.001 for the entire group in the superior (t = 4.78 and anterior (t = 4.04 cingulate, right thalamus (t = 4.66 and left hippocampus (t = 3.96. Deactivation (p = 0.001 within the left precentral (t = 4.26, right mid-frontal (t = 4.03, right inferior frontal (t = 3.99, left prefrontal (3.81 and right precuneus (t= 3.85 was more marked in treatment responders. No pattern of baseline activation distinguished responders from non-responders to subsequent pharmacotherapy. Conclusions Although each of the anxiety disorders may be mediated by different

  14. Wireless Technologies, Ubiquitous Computing and Mobile Health: Application to Drug Abuse Treatment and Compliance with HIV Therapies.

    Science.gov (United States)

    Boyer, Edward W; Smelson, David; Fletcher, Richard; Ziedonis, Douglas; Picard, Rosalind W

    2010-06-01

    Beneficial advances in the treatment of substance abuse and compliance with medical therapies, including HAART, are possible with new mobile technologies related to personal physiological sensing and computational methods. When incorporated into mobile platforms that allow for ubiquitous computing, these technologies have great potential for extending the reach of behavioral interventions from clinical settings where they are learned into natural environments.

  15. Computer simulation of the off gas treatment process for the KEPCO pilot vitrification plant

    International Nuclear Information System (INIS)

    Kim, Hey Suk; Maeng, Sung Jun; Lee, Myung Chan

    1999-01-01

    Vitrification technology for treatment of low and intermediate radioactive wastes can remarkably reduce waste volume to about one twentieth of the initial volume as they are collected and converted into a very stable form. Therefore, it can minimize environmental impact when the vitrified waste is disposed of. But an off gas treatment system is necessary to apply this technology because air pollutants and radioisotopes are generated like those of other conventional incinerators during thermal oxidation process at high temperature. KEPCO designed and installed a pilot scale vitrification plant to demonstrate the feasibility of the vitrification process and then to make a conceptual design for a commercial vitrification facility. The purpose of this study was to simulate the off gas treatment system(OGTS) in order optimize the operating conditions. Mass balance and temperature profile in the off gas treatment system were simulated for different combinations of combustible wastes by computer simulation code named OGTS code and removal efficiency of each process was also calculated with change of design parameters. The OGTS code saved efforts,time and capital because scale and configuration of the system could be easily changed. The simulation result of the pilot scale off gas process as well as pilot tests will be of great use in the future for a design of the commercial vitrification facility. (author)

  16. COMPUTING

    CERN Multimedia

    P. McBride

    It has been a very active year for the computing project with strong contributions from members of the global community. The project has focused on site preparation and Monte Carlo production. The operations group has begun processing data from P5 as part of the global data commissioning. Improvements in transfer rates and site availability have been seen as computing sites across the globe prepare for large scale production and analysis as part of CSA07. Preparations for the upcoming Computing Software and Analysis Challenge CSA07 are progressing. Ian Fisk and Neil Geddes have been appointed as coordinators for the challenge. CSA07 will include production tests of the Tier-0 production system, reprocessing at the Tier-1 sites and Monte Carlo production at the Tier-2 sites. At the same time there will be a large analysis exercise at the Tier-2 centres. Pre-production simulation of the Monte Carlo events for the challenge is beginning. Scale tests of the Tier-0 will begin in mid-July and the challenge it...

  17. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction During the past six months, Computing participated in the STEP09 exercise, had a major involvement in the October exercise and has been working with CMS sites on improving open issues relevant for data taking. At the same time operations for MC production, real data reconstruction and re-reconstructions and data transfers at large scales were performed. STEP09 was successfully conducted in June as a joint exercise with ATLAS and the other experiments. It gave good indication about the readiness of the WLCG infrastructure with the two major LHC experiments stressing the reading, writing and processing of physics data. The October Exercise, in contrast, was conducted as an all-CMS exercise, where Physics, Computing and Offline worked on a common plan to exercise all steps to efficiently access and analyze data. As one of the major results, the CMS Tier-2s demonstrated to be fully capable for performing data analysis. In recent weeks, efforts were devoted to CMS Computing readiness. All th...

  18. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion The Tier 0 infrastructure was able to repack and promptly reconstruct heavy-ion collision data. Two copies were made of the data at CERN using a large CASTOR disk pool, and the core physics sample was replicated ...

  19. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

    Introduction Computing continued with a high level of activity over the winter in preparation for conferences and the start of the 2012 run. 2012 brings new challenges with a new energy, more complex events, and the need to make the best use of the available time before the Long Shutdown. We expect to be resource constrained on all tiers of the computing system in 2012 and are working to ensure the high-priority goals of CMS are not impacted. Heavy ions After a successful 2011 heavy-ion run, the programme is moving to analysis. During the run, the CAF resources were well used for prompt analysis. Since then in 2012 on average 200 job slots have been used continuously at Vanderbilt for analysis workflows. Operations Office As of 2012, the Computing Project emphasis has moved from commissioning to operation of the various systems. This is reflected in the new organisation structure where the Facilities and Data Operations tasks have been merged into a common Operations Office, which now covers everything ...

  20. COMPUTING

    CERN Multimedia

    M. Kasemann

    CCRC’08 challenges and CSA08 During the February campaign of the Common Computing readiness challenges (CCRC’08), the CMS computing team had achieved very good results. The link between the detector site and the Tier0 was tested by gradually increasing the number of parallel transfer streams well beyond the target. Tests covered the global robustness at the Tier0, processing a massive number of very large files and with a high writing speed to tapes.  Other tests covered the links between the different Tiers of the distributed infrastructure and the pre-staging and reprocessing capacity of the Tier1’s: response time, data transfer rate and success rate for Tape to Buffer staging of files kept exclusively on Tape were measured. In all cases, coordination with the sites was efficient and no serious problem was found. These successful preparations prepared the ground for the second phase of the CCRC’08 campaign, in May. The Computing Software and Analysis challen...

  1. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction The first data taking period of November produced a first scientific paper, and this is a very satisfactory step for Computing. It also gave the invaluable opportunity to learn and debrief from this first, intense period, and make the necessary adaptations. The alarm procedures between different groups (DAQ, Physics, T0 processing, Alignment/calibration, T1 and T2 communications) have been reinforced. A major effort has also been invested into remodeling and optimizing operator tasks in all activities in Computing, in parallel with the recruitment of new Cat A operators. The teams are being completed and by mid year the new tasks will have been assigned. CRB (Computing Resource Board) The Board met twice since last CMS week. In December it reviewed the experience of the November data-taking period and could measure the positive improvements made for the site readiness. It also reviewed the policy under which Tier-2 are associated with Physics Groups. Such associations are decided twice per ye...

  2. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the co...

  3. An external irradiation treatment planning system installed on a personal computer. 137

    International Nuclear Information System (INIS)

    Kunieda, Etso; Ogawa, Koichi; Mita, Kazumasa; Sekiguchi, Kozo; Wada, Tadashi; Hashimoto, Shyozo

    1987-01-01

    A compact and practical treatment planning system for external photon therapy has been developed for use on a desk-top personal computer. The system calculates the dose distributions of inhomogeneous density fields by using the CT-value of each pixel and displays isodose curves on the CRT superimposed on the gray scale CT image or on a hard-copy. Inhomogeneity correction is based on the TAR method where the path length from the calculation point to the surface is determined by summing up electron density derived from the CT-values of pixels on the path. Wedge filter correction is also available by using stored geometric data. The contour of patients is acquired by tracting the CT image on the light panel of the digitizer, or directly from the digital CT data. Though some critical parts of the programs are written in machine language, the system is mostly in BASIC and C languages. The minimum required hardware consists of a MS-DOS based personal computer, a color CRT display, an 8 inch floppy disk drive and a digitizer. They are generally available in Japan at reasonable cost. Tests were carried out in homogeneous and inhomogeneous density phantoms to evaluate the accuracy of the acquired dosage, and showed reasonable results compared with other commercially available treatment planning systems. The overall calculation time is satisfactory for multiple beam calculations. 5 refs.; 3 figs

  4. Role of whole-body 64-slice multidetector computed tomography in treatment planning for multiple myeloma.

    Science.gov (United States)

    Razek, Ahmed Abdel Khalek Abdel; Ezzat, Amany; Azmy, Emad; Tharwat, Nehal

    2013-08-01

    The authors evaluated the role of whole-body 64-slice multidetector computed tomography (WB-MDCT) in treatment planning for multiple myeloma. This was a prospective study of 28 consecutive patients with multiple myeloma (19 men, nine women; age range, 51-73 years; mean age, 60 years) who underwent WB-MDCT and conventional radiography (CR) of the skeleton. The images were interpreted for the presence of bony lesions, medullary lesions, fractures and extraosseous lesions. We evaluated any changes in treatment planning as a result of WB-MDCT findings. WB-MDCT was superior to CR for detecting bony lesions (p=0.001), especially of the spine (p=0.001) and thoracic cage (p=0.006). WB-MDCT upstaged 14 patients, with a significant difference in staging (p=0.002) between WB-MDCT and CR. Medullary involvement either focal (n=6) or diffuse (n=3) had a positive correlation with the overall score (r=0.790) and stage (r=0.618) of disease. Spine fractures were better detected at WB-MDCT (n=4) than at CR (n=2). Extraosseous soft tissue lesions (n=7) were detected only at WB-MDCT. Findings detected at the WB-MDCT led to changes in the patient's treatment plan in 39% of cases. Upstaging of seven patients (25%) altered the medical treatment plan, and four of 28 (14%) patients required additional radiotherapy (7%) and vertebroplasty (7%). We conclude that WB-MDCT has an impact on treatment planning and prognosis in patients with multiple myeloma, as it has high rate of detecting cortical and medullary bone lesions, spinal fracture and extraosseous lesions. This information may alter treatment planning in multiple myeloma due to disease upstaging and detection of spine fracture and extraosseous spinal lesions.

  5. Three-dimensional photoacoustic tomography based on graphics-processing-unit-accelerated finite element method.

    Science.gov (United States)

    Peng, Kuan; He, Ling; Zhu, Ziqiang; Tang, Jingtian; Xiao, Jiaying

    2013-12-01

    Compared with commonly used analytical reconstruction methods, the frequency-domain finite element method (FEM) based approach has proven to be an accurate and flexible algorithm for photoacoustic tomography. However, the FEM-based algorithm is computationally demanding, especially for three-dimensional cases. To enhance the algorithm's efficiency, in this work a parallel computational strategy is implemented in the framework of the FEM-based reconstruction algorithm using a graphic-processing-unit parallel frame named the "compute unified device architecture." A series of simulation experiments is carried out to test the accuracy and accelerating effect of the improved method. The results obtained indicate that the parallel calculation does not change the accuracy of the reconstruction algorithm, while its computational cost is significantly reduced by a factor of 38.9 with a GTX 580 graphics card using the improved method.

  6. 3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions

    Directory of Open Access Journals (Sweden)

    CAVALCANTI Marcelo de Gusmão Paraiso

    2001-01-01

    Full Text Available In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

  7. 3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions.

    Science.gov (United States)

    Cavalcanti, M G; Ruprecht, A; Vannier, M W

    2001-01-01

    In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

  8. Computational models as predictors of HIV treatment outcomes for the Phidisa cohort in South Africa

    Directory of Open Access Journals (Sweden)

    Andrew Revell

    2016-06-01

    Full Text Available Background: Selecting the optimal combination of HIV drugs for an individual in resourcelimited settings is challenging because of the limited availability of drugs and genotyping. Objective: The evaluation as a potential treatment support tool of computational models that predict response to therapy without a genotype, using cases from the Phidisa cohort in South Africa. Methods: Cases from Phidisa of treatment change following failure were identified that had the following data available: baseline CD4 count and viral load, details of failing and previous antiretroviral drugs, drugs in new regimen and time to follow-up. The HIV Resistance Response Database Initiative’s (RDI’s models used these data to predict the probability of a viral load < 50 copies/mL at follow-up. The models were also used to identify effective alternative combinations of three locally available drugs. Results: The models achieved accuracy (area under the receiver–operator characteristic curve of 0.72 when predicting response to therapy, which is less accurate than for an independent global test set (0.80 but at least comparable to that of genotyping with rules-based interpretation. The models were able to identify alternative locally available three-drug regimens that were predicted to be effective in 69% of all cases and 62% of those whose new treatment failed in the clinic. Conclusion: The predictive accuracy of the models for these South African patients together with the results of previous studies suggest that the RDI’s models have the potential to optimise treatment selection and reduce virological failure in different patient populations, without the use of a genotype. Keywords: HIV therapy; mathematical modelling; treatment; genotype

  9. COMPUTING

    CERN Multimedia

    2010-01-01

    Introduction Just two months after the “LHC First Physics” event of 30th March, the analysis of the O(200) million 7 TeV collision events in CMS accumulated during the first 60 days is well under way. The consistency of the CMS computing model has been confirmed during these first weeks of data taking. This model is based on a hierarchy of use-cases deployed between the different tiers and, in particular, the distribution of RECO data to T1s, who then serve data on request to T2s, along a topology known as “fat tree”. Indeed, during this period this model was further extended by almost full “mesh” commissioning, meaning that RECO data were shipped to T2s whenever possible, enabling additional physics analyses compared with the “fat tree” model. Computing activities at the CMS Analysis Facility (CAF) have been marked by a good time response for a load almost evenly shared between ALCA (Alignment and Calibration tasks - highest p...

  10. COMPUTING

    CERN Multimedia

    Contributions from I. Fisk

    2012-01-01

    Introduction The start of the 2012 run has been busy for Computing. We have reconstructed, archived, and served a larger sample of new data than in 2011, and we are in the process of producing an even larger new sample of simulations at 8 TeV. The running conditions and system performance are largely what was anticipated in the plan, thanks to the hard work and preparation of many people. Heavy ions Heavy Ions has been actively analysing data and preparing for conferences.  Operations Office Figure 6: Transfers from all sites in the last 90 days For ICHEP and the Upgrade efforts, we needed to produce and process record amounts of MC samples while supporting the very successful data-taking. This was a large burden, especially on the team members. Nevertheless the last three months were very successful and the total output was phenomenal, thanks to our dedicated site admins who keep the sites operational and the computing project members who spend countless hours nursing the...

  11. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction A large fraction of the effort was focused during the last period into the preparation and monitoring of the February tests of Common VO Computing Readiness Challenge 08. CCRC08 is being run by the WLCG collaboration in two phases, between the centres and all experiments. The February test is dedicated to functionality tests, while the May challenge will consist of running at all centres and with full workflows. For this first period, a number of functionality checks of the computing power, data repositories and archives as well as network links are planned. This will help assess the reliability of the systems under a variety of loads, and identifying possible bottlenecks. Many tests are scheduled together with other VOs, allowing the full scale stress test. The data rates (writing, accessing and transfer¬ring) are being checked under a variety of loads and operating conditions, as well as the reliability and transfer rates of the links between Tier-0 and Tier-1s. In addition, the capa...

  12. COMPUTING

    CERN Multimedia

    Matthias Kasemann

    Overview The main focus during the summer was to handle data coming from the detector and to perform Monte Carlo production. The lessons learned during the CCRC and CSA08 challenges in May were addressed by dedicated PADA campaigns lead by the Integration team. Big improvements were achieved in the stability and reliability of the CMS Tier1 and Tier2 centres by regular and systematic follow-up of faults and errors with the help of the Savannah bug tracking system. In preparation for data taking the roles of a Computing Run Coordinator and regular computing shifts monitoring the services and infrastructure as well as interfacing to the data operations tasks are being defined. The shift plan until the end of 2008 is being put together. User support worked on documentation and organized several training sessions. The ECoM task force delivered the report on “Use Cases for Start-up of pp Data-Taking” with recommendations and a set of tests to be performed for trigger rates much higher than the ...

  13. COMPUTING

    CERN Multimedia

    P. MacBride

    The Computing Software and Analysis Challenge CSA07 has been the main focus of the Computing Project for the past few months. Activities began over the summer with the preparation of the Monte Carlo data sets for the challenge and tests of the new production system at the Tier-0 at CERN. The pre-challenge Monte Carlo production was done in several steps: physics generation, detector simulation, digitization, conversion to RAW format and the samples were run through the High Level Trigger (HLT). The data was then merged into three "Soups": Chowder (ALPGEN), Stew (Filtered Pythia) and Gumbo (Pythia). The challenge officially started when the first Chowder events were reconstructed on the Tier-0 on October 3rd. The data operations teams were very busy during the the challenge period. The MC production teams continued with signal production and processing while the Tier-0 and Tier-1 teams worked on splitting the Soups into Primary Data Sets (PDS), reconstruction and skimming. The storage sys...

  14. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing operation has been lower as the Run 1 samples are completing and smaller samples for upgrades and preparations are ramping up. Much of the computing activity is focusing on preparations for Run 2 and improvements in data access and flexibility of using resources. Operations Office Data processing was slow in the second half of 2013 with only the legacy re-reconstruction pass of 2011 data being processed at the sites.   Figure 1: MC production and processing was more in demand with a peak of over 750 Million GEN-SIM events in a single month.   Figure 2: The transfer system worked reliably and efficiently and transferred on average close to 520 TB per week with peaks at close to 1.2 PB.   Figure 3: The volume of data moved between CMS sites in the last six months   The tape utilisation was a focus for the operation teams with frequent deletion campaigns from deprecated 7 TeV MC GEN-SIM samples to INVALID datasets, which could be cleaned up...

  15. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

      Introduction Computing activity has been running at a sustained, high rate as we collect data at high luminosity, process simulation, and begin to process the parked data. The system is functional, though a number of improvements are planned during LS1. Many of the changes will impact users, we hope only in positive ways. We are trying to improve the distributed analysis tools as well as the ability to access more data samples more transparently.  Operations Office Figure 2: Number of events per month, for 2012 Since the June CMS Week, Computing Operations teams successfully completed data re-reconstruction passes and finished the CMSSW_53X MC campaign with over three billion events available in AOD format. Recorded data was successfully processed in parallel, exceeding 1.2 billion raw physics events per month for the first time in October 2012 due to the increase in data-parking rate. In parallel, large efforts were dedicated to WMAgent development and integrati...

  16. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction The Computing Team successfully completed the storage, initial processing, and distribution for analysis of proton-proton data in 2011. There are still a variety of activities ongoing to support winter conference activities and preparations for 2012. Heavy ions The heavy-ion run for 2011 started in early November and has already demonstrated good machine performance and success of some of the more advanced workflows planned for 2011. Data collection will continue until early December. Facilities and Infrastructure Operations Operational and deployment support for WMAgent and WorkQueue+Request Manager components, routinely used in production by Data Operations, are provided. The GlideInWMS and components installation are now deployed at CERN, which is added to the GlideInWMS factory placed in the US. There has been new operational collaboration between the CERN team and the UCSD GlideIn factory operators, covering each others time zones by monitoring/debugging pilot jobs sent from the facto...

  17. Multi-level computational chemistry study on hydrogen recombination catalyst of off-gas treatment system

    International Nuclear Information System (INIS)

    Hatakeyama, Nozomu; Ise, Mariko; Inaba, Kenji

    2011-01-01

    In order to reveal the deactivation mechanism of the hydrogen recombination catalyst of off-gas treatment system, we investigate by using multi-level computational chemistry simulation methods. The recombiner apparatus is modeled by the numerical mesh system in the axial coordinates, and unsteady, advection and reaction rate equations are solved by using a finite difference method. The chemical reactions are formulated to represent adsorption-desorption of hydrogen and oxygen on Pt catalyst, and time developments of the coverage factors of Pt are solved numerically. The computational simulations successfully reproduce the very similar behaviors observed by experiments, such as increasing of the inversion rates of H 2 to H 2 O, the temperatures distributions along the flow direction, dependencies of experimental condition, and so on. Thus Pt poisoning is considered to cause the deactivation of the hydrogen recombination catalyst. To clarify the poisoning mechanism, the molecular level simulation is applied to the system of Pt on boehmite attacked by a cyclic siloxane which has been detected by experiments and considered as one of poisoning spices. The simulation shows ring-opening reaction of the cyclic siloxane on Pt, then attachment of two ends of the chain-like siloxane to Pt and boehmite, respectively, and that finally the recombination reaction is prevented. This may be the first study to find out the detailed dynamical mechanism of hydrogen recombination catalyst poisoning with cyclic siloxane. (author)

  18. Semiquantitative visual approach to scoring lung cancer treatment response using computed tomography: a pilot study.

    Science.gov (United States)

    Gottlieb, Ronald H; Kumar, Prasanna; Loud, Peter; Klippenstein, Donald; Raczyk, Cheryl; Tan, Wei; Lu, Jenny; Ramnath, Nithya

    2009-01-01

    Our objective was to compare a newly developed semiquantitative visual scoring (SVS) method with the current standard, the Response Evaluation Criteria in Solid Tumors (RECIST) method, in the categorization of treatment response and reader agreement for patients with metastatic lung cancer followed by computed tomography. The 18 subjects (5 women and 13 men; mean age, 62.8 years) were from an institutional review board-approved phase 2 study that evaluated a second-line chemotherapy regimen for metastatic (stages III and IV) non-small cell lung cancer. Four radiologists, blinded to the patient outcome and each other's reads, evaluated the change in the patients' tumor burden from the baseline to the first restaging computed tomographic scan using either the RECIST or the SVS method. We compared the numbers of patients placed into the partial response, the stable disease (SD), and the progressive disease (PD) categories (Fisher exact test) and observer agreement (kappa statistic). Requiring the concordance of 3 of the 4 readers resulted in the RECIST placing 17 (100%) of 17 patients in the SD category compared with the SVS placing 9 (60%) of 15 patients in the partial response, 5 (33%) of the 15 patients in the SD, and 1 (6.7%) of the 15 patients in the PD categories (P < 0.0001). Interobserver agreement was higher among the readers using the SVS method (kappa, 0.54; P < 0.0001) compared with that of the readers using the RECIST method (kappa, -0.01; P = 0.5378). Using the SVS method, the readers more finely discriminated between the patient response categories with superior agreement compared with the RECIST method, which could potentially result in large differences in early treatment decisions for advanced lung cancer.

  19. COMPUTING

    CERN Multimedia

    M. Kasemann

    CMS relies on a well functioning, distributed computing infrastructure. The Site Availability Monitoring (SAM) and the Job Robot submission have been very instrumental for site commissioning in order to increase availability of more sites such that they are available to participate in CSA07 and are ready to be used for analysis. The commissioning process has been further developed, including "lessons learned" documentation via the CMS twiki. Recently the visualization, presentation and summarizing of SAM tests for sites has been redesigned, it is now developed by the central ARDA project of WLCG. Work to test the new gLite Workload Management System was performed; a 4 times increase in throughput with respect to LCG Resource Broker is observed. CMS has designed and launched a new-generation traffic load generator called "LoadTest" to commission and to keep exercised all data transfer routes in the CMS PhE-DEx topology. Since mid-February, a transfer volume of about 12 P...

  20. Development and application of computer assisted optimal method for treatment of femoral neck fracture.

    Science.gov (United States)

    Wang, Monan; Zhang, Kai; Yang, Ning

    2018-04-09

    To help doctors decide their treatment from the aspect of mechanical analysis, the work built a computer assisted optimal system for treatment of femoral neck fracture oriented to clinical application. The whole system encompassed the following three parts: Preprocessing module, finite element mechanical analysis module, post processing module. Preprocessing module included parametric modeling of bone, parametric modeling of fracture face, parametric modeling of fixed screw and fixed position and input and transmission of model parameters. Finite element mechanical analysis module included grid division, element type setting, material property setting, contact setting, constraint and load setting, analysis method setting and batch processing operation. Post processing module included extraction and display of batch processing operation results, image generation of batch processing operation, optimal program operation and optimal result display. The system implemented the whole operations from input of fracture parameters to output of the optimal fixed plan according to specific patient real fracture parameter and optimal rules, which demonstrated the effectiveness of the system. Meanwhile, the system had a friendly interface, simple operation and could improve the system function quickly through modifying single module.

  1. Computed tomography as a source of electron density information for radiation treatment planning

    International Nuclear Information System (INIS)

    Skrzynski, Witold; Slusarczyk-Kacprzyk, Wioletta; Bulski, Wojciech; Zielinska-Dabrowska, Sylwia; Wachowicz, Marta; Kukolowicz, Pawel F.

    2010-01-01

    Purpose: to evaluate the performance of computed tomography (CT) systems of various designs as a source of electron density (ρ el ) data for treatment planning of radiation therapy. Material and methods: dependence of CT numbers on relative electron density of tissue-equivalent materials (HU-ρ el relationship) was measured for several general-purpose CT systems (single-slice, multislice, wide-bore multislice), for radiotherapy simulators with a single-slice CT and kV CBCT (cone-beam CT) options, as well as for linear accelerators with kV and MV CBCT systems. Electron density phantoms of four sizes were used. Measurement data were compared with the standard HU-ρ el relationships predefined in two commercial treatment-planning systems (TPS). Results: the HU-ρ el relationships obtained with all of the general-purpose CT scanners operating at voltages close to 120 kV were very similar to each other and close to those predefined in TPS. Some dependency of HU values on tube voltage was observed for bone-equivalent materials. For a given tube voltage, differences in results obtained for different phantoms were larger than those obtained for different CT scanners. For radiotherapy simulators and for kV CBCT systems, the information on ρ el was much less precise because of poor uniformity of images. For MV CBCT, the results were significantly different than for kV systems due to the differing energy spectrum of the beam. Conclusion: the HU-ρ el relationships predefined in TPS can be used for general-purpose CT systems operating at voltages close to 120 kV. For nontypical imaging systems (e.g., CBCT), the relationship can be significantly different and, therefore, it should always be measured and carefully analyzed before using CT data for treatment planning. (orig.)

  2. Cone beam computed tomography image guidance system for a dedicated intracranial radiosurgery treatment unit.

    Science.gov (United States)

    Ruschin, Mark; Komljenovic, Philip T; Ansell, Steve; Ménard, Cynthia; Bootsma, Gregory; Cho, Young-Bin; Chung, Caroline; Jaffray, David

    2013-01-01

    Image guidance has improved the precision of fractionated radiation treatment delivery on linear accelerators. Precise radiation delivery is particularly critical when high doses are delivered to complex shapes with steep dose gradients near critical structures, as is the case for intracranial radiosurgery. To reduce potential geometric uncertainties, a cone beam computed tomography (CT) image guidance system was developed in-house to generate high-resolution images of the head at the time of treatment, using a dedicated radiosurgery unit. The performance and initial clinical use of this imaging system are described. A kilovoltage cone beam CT system was integrated with a Leksell Gamma Knife Perfexion radiosurgery unit. The X-ray tube and flat-panel detector are mounted on a translational arm, which is parked above the treatment unit when not in use. Upon descent, a rotational axis provides 210° of rotation for cone beam CT scans. Mechanical integrity of the system was evaluated over a 6-month period. Subsequent clinical commissioning included end-to-end testing of targeting performance and subjective image quality performance in phantoms. The system has been used to image 2 patients, 1 of whom received single-fraction radiosurgery and 1 who received 3 fractions, using a relocatable head frame. Images of phantoms demonstrated soft tissue contrast visibility and submillimeter spatial resolution. A contrast difference of 35 HU was easily detected at a calibration dose of 1.2 cGy (center of head phantom). The shape of the mechanical flex vs scan angle was highly reproducible and exhibited cone beam CT image guidance system was successfully adapted to a radiosurgery unit. The system is capable of producing high-resolution images of bone and soft tissue. The system is in clinical use and provides excellent image guidance without invasive frames. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Tally and geometry definition influence on the computing time in radiotherapy treatment planning with MCNP Monte Carlo code.

    Science.gov (United States)

    Juste, B; Miro, R; Gallardo, S; Santos, A; Verdu, G

    2006-01-01

    The present work has simulated the photon and electron transport in a Theratron 780 (MDS Nordion) (60)Co radiotherapy unit, using the Monte Carlo transport code, MCNP (Monte Carlo N-Particle), version 5. In order to become computationally more efficient in view of taking part in the practical field of radiotherapy treatment planning, this work is focused mainly on the analysis of dose results and on the required computing time of different tallies applied in the model to speed up calculations.

  4. Estimation of the failure risk of a maxillary premolar with different crack depths with endodontic treatment by computer-aided design/computer-aided manufacturing ceramic restorations.

    Science.gov (United States)

    Lin, Chun-Li; Chang, Yen-Hsiang; Hsieh, Shih-Kai; Chang, Wen-Jen

    2013-03-01

    This study evaluated the risk of failure for an endodontically treated premolar with different crack depths, which was shearing toward the pulp chamber and was restored by using 3 different computer-aided design/computer-aided manufacturing ceramic restoration configurations. Three 3-dimensional finite element models designed with computer-aided design/computer-aided manufacturing ceramic onlay, endocrown, and conventional crown restorations were constructed to perform simulations. The Weibull function was incorporated with finite element analysis to calculate the long-term failure probability relative to different load conditions. The results indicated that the stress values on the enamel, dentin, and luting cement for endocrown restorations exhibited the lowest values relative to the other 2 restoration methods. Weibull analysis revealed that the overall failure probabilities in a shallow cracked premolar were 27%, 2%, and 1% for the onlay, endocrown, and conventional crown restorations, respectively, in the normal occlusal condition. The corresponding values were 70%, 10%, and 2% for the depth cracked premolar. This numeric investigation suggests that the endocrown provides sufficient fracture resistance only in a shallow cracked premolar with endodontic treatment. The conventional crown treatment can immobilize the premolar for different cracked depths with lower failure risk. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Positron emission tomography/computed tomography and biomarkers for early treatment response evaluation in metastatic colon cancer

    DEFF Research Database (Denmark)

    Engelmann, Bodil E.; Loft, Annika; Kjær, Andreas

    2014-01-01

    BACKGROUND: Treatment options for metastatic colon cancer (mCC) are widening. We prospectively evaluated serial 2-deoxy-2-[18F]fluoro-d-glucose positron-emission tomography/computed tomography (PET/CT) and measurements of tissue inhibitor of metalloproteinases-1 (TIMP-1), carcinoembryonic antigen...... evaluated by PET/CT before treatment, after one and four treatment series. Morphological and metabolic response was independently assessed according to Response Evaluation Criteria in Solid Tumors and European Organization for Research and Treatment of Cancer PET criteria. Plasma TIMP-1, plasma u...

  6. Accuracy of treatment planning based on stereolithography in computer assisted surgery

    International Nuclear Information System (INIS)

    Schicho, Kurt; Figl, Michael; Seemann, Rudolf; Ewers, Rolf; Lambrecht, J. Thomas; Wagner, Arne; Watzinger, Franz; Baumann, Arnulf; Kainberger, Franz; Fruehwald, Julia; Klug, Clemens

    2006-01-01

    Three-dimensional stereolithographic models (SL models), made of solid acrylic resin derived from computed-tomography (CT) data, are an established tool for preoperative treatment planning in numerous fields of medicine. An innovative approach, combining stereolithography with computer-assisted point-to-point navigation, can support the precise surgical realization of a plan that has been defined on an SL model preoperatively. The essential prerequisites for the application of such an approach are: (1) The accuracy of the SL models (including accuracy of the CT scan and correspondence of the model with the patient's anatomy) and (2) the registration method used for the transfer of the plan from the SL model to the patient (i.e., whether the applied registration markers can be added to the SL model corresponding to the markers at the patient with an accuracy that keeps the ''cumulative error'' at the end of the chain of errors, in the order of the accuracy of contemporary navigation systems). In this study, we focus on these two topics: By applying image-matching techniques, we fuse the original CT data of the patient with the corresponding CT data of the scanned SL model, and measure the deviations of defined parameter (e.g., distances between anatomical points). To evaluate the registration method used for the planning transfer, we apply a point-merge algorithm, using four marker points that should be located at exactly corresponding positions at the patient and at connective bars that are added to the surface of the SL model. Again, deviations at defined anatomical structures are measured and analyzed statistically. Our results prove sufficient correspondence of the two data sets and accuracy of the registration method for routine clinical application. The evaluation of the SL model accuracy revealed an arithmetic mean of the relative deviations from 0.8% to 5.4%, with an overall mean deviation of 2.2%. Mean deviations of the investigated anatomical structures

  7. [APPLICATION OF COMPUTER-ASSISTED SURGICAL PLANNING IN SURGICAL TREATMENT OF ANKLE FRACTURES].

    Science.gov (United States)

    Xia, Shengli; Wang, Xiuhui; Fu, Beigang; Lu, Yaogang; Wang, Minghui

    2015-12-01

    To explore the clinical value of computer-assisted surgical planning in the treatment of ankle fractures. Between January 2012 and January 2014, open reduction and internal fixation were performed on 42 patients with ankle fractures. There were 22 males and 20 females with an average age of 52 years (range, 19-72 years). The causes were spraining injury (20 cases), traffic accident injury (14 cases), and falling from height injury (8 cases). The time from injury to operation was 5 hours to 12 days (mean, 2.5 days). All fractures were closed trimalleolar fractures. According to Lauge-Hansen classification, 25 cases were rated as supination extorsion type IV, 13 as pronation extorsion type IV, and 4 as pronation abduction type III. The preoperative planning was made by virtual reduction and internal fixation using Superimage software. The mean operation time was 93.7 minutes (range, 76-120 minutes). Delayed wound healing occurred in 1 case, and secondary healing was obtained after treatment; primary healing of incision was achieved in the other patients. Postoperative X-ray films and CT images showed anatomic reduction of fracture and good position of internal fixation. All patients were followed up 14.6 months on average (range, 9-27 months). The range of motion of the affected ankle was close to the normal side at 6-8 weeks. The mean fracture healing time was 13.1 weeks (range, 11-17 weeks). Degenerative change of the ankle joint was observed in 3 cases (7.1%) with manifestation of mild narrowing of joint space on the X-ray films at last follow-up. According to Baird-Jackson score system, the results were excellent in 24 cases, good in 13 cases, and fair in 5 cases, with an excellent and good rate of 88%. Computer-assisted surgical planning for ankle fractures can help surgeons identify type of ankle fractures and improve surgical scheme for guiding fracture reduction and selecting and placing implants, so good effectiveness can be obtained.

  8. Mixed Total Variation and L1 Regularization Method for Optical Tomography Based on Radiative Transfer Equation

    Directory of Open Access Journals (Sweden)

    Jinping Tang

    2017-01-01

    Full Text Available Optical tomography is an emerging and important molecular imaging modality. The aim of optical tomography is to reconstruct optical properties of human tissues. In this paper, we focus on reconstructing the absorption coefficient based on the radiative transfer equation (RTE. It is an ill-posed parameter identification problem. Regularization methods have been broadly applied to reconstruct the optical coefficients, such as the total variation (TV regularization and the L1 regularization. In order to better reconstruct the piecewise constant and sparse coefficient distributions, TV and L1 norms are combined as the regularization. The forward problem is discretized with the discontinuous Galerkin method on the spatial space and the finite element method on the angular space. The minimization problem is solved by a Jacobian-based Levenberg-Marquardt type method which is equipped with a split Bregman algorithms for the L1 regularization. We use the adjoint method to compute the Jacobian matrix which dramatically improves the computation efficiency. By comparing with the other imaging reconstruction methods based on TV and L1 regularizations, the simulation results show the validity and efficiency of the proposed method.

  9. Image reconstruction of fluorescent molecular tomography based on the tree structured Schur complement decomposition

    Directory of Open Access Journals (Sweden)

    Wang Jiajun

    2010-05-01

    Full Text Available Abstract Background The inverse problem of fluorescent molecular tomography (FMT often involves complex large-scale matrix operations, which may lead to unacceptable computational errors and complexity. In this research, a tree structured Schur complement decomposition strategy is proposed to accelerate the reconstruction process and reduce the computational complexity. Additionally, an adaptive regularization scheme is developed to improve the ill-posedness of the inverse problem. Methods The global system is decomposed level by level with the Schur complement system along two paths in the tree structure. The resultant subsystems are solved in combination with the biconjugate gradient method. The mesh for the inverse problem is generated incorporating the prior information. During the reconstruction, the regularization parameters are adaptive not only to the spatial variations but also to the variations of the objective function to tackle the ill-posed nature of the inverse problem. Results Simulation results demonstrate that the strategy of the tree structured Schur complement decomposition obviously outperforms the previous methods, such as the conventional Conjugate-Gradient (CG and the Schur CG methods, in both reconstruction accuracy and speed. As compared with the Tikhonov regularization method, the adaptive regularization scheme can significantly improve ill-posedness of the inverse problem. Conclusions The methods proposed in this paper can significantly improve the reconstructed image quality of FMT and accelerate the reconstruction process.

  10. Individualized treatment of craniovertebral junction malformation guided by intraoperative computed tomography.

    Science.gov (United States)

    Li, Lianfeng; Wang, Peng; Chen, LiFeng; Ma, Xiaodong; Bu, Bo; Yu, Xinguang

    2012-04-01

    This study was designed to report our preliminary experience of intraoperative computed tomography (iCT) using a mobile scanner with integrated neuronavigation system (NNS). The objective of this study was to assess the feasibility and potential utility of iCT with integrated NNS in individualized treatment of craniovertebral junction malformation (CVJM). The surgical management of congenital craniovertebral anomalies is complex due to the relative difficulty in accessing the region, critical relationships of neurovascular structures, and the intricate biomechanical issues involved. We reported our first 19 complex CVJM cases including 11 male and 8 female patients from January, 2009 to June, 2009 (mean age, 33.9 y; age range, 13 to 58 y). A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. Image data was transferred directly from the scanner into the NNS using an automated registration system. We applied this technology to transoral odontoidectomy in 17 patients. Moreover, with the extra help of iCT integrated with NNS, odontoidectomy through posterior midline approach, and transoral atlantal lateral mass resection were, for the first time, performed for treatment of complex CVJM. NNS was found to correlate well with the intraoperative findings, and the recalibration was uneven in all cases with an accuracy of 1.6 mm (1.6: 1.2 to 2.0). All patients were clinically evaluated by Nurick grade criteria, and neurological deficits were monitored after 3 months of surgery. Fifteen patients (79%) were improved by at least 1 Nurick grade, whereas the grade did not change in 4 patients (21%). iCT scanning with integrated NNS was both feasible and beneficial for the surgical management of complex CVJM. In this unusual patient population, the technique seemed to be valuable in negotiating complex anatomy and achieving a safe and predictable decompression.

  11. Feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in lung cancer treatment planning

    International Nuclear Information System (INIS)

    Xiao Jianghong; Zhang Hong; Gong Youling; Fu Yuchuan; Tang Bin; Wang Shichao; Jiang Qingfeng; Li Ping

    2010-01-01

    Background and purpose: To investigate the feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in 3-dimensional conformal radiotherapy (3D-CRT), stereotactic body radiation therapy (SBRT) and intensity-modulated radiotherapy (IMRT) treatment planning for lung cancers, respectively. Materials and methods: Twelve patients with bulky lung tumors and 14 patients with small lung tumors were retrospectively analyzed. Each patient took two sets of CT in the same position with active breathing control (ABC) technique before and after intravenous contrast agent (CA) injections. Bulky tumors were planned with 3D-CRT, while SBRT plans were generated for patients with small tumors based on CT scans with intravenous CA. In addition, IMRT plans were generated for patients with bulky tumors to continue on a planning study. All plans were copied and replaced on the scans without intravenous CA. The radiation doses calculated from the two sets of CTs were compared with regard to planning volumes (PTV), the organ at-risk (OAR) and the lungs using Wilcoxon's signed rank test. Results: In comparisons for 3D-CRT plans, CT scans with intravenous CA reduced the mean dose and the maximum dose of PTV with significant differences (p 95 ) for targets, respectively (p < 0.05). There was no statistical significance for lung parameters between two sets of scans in SBRT plans and IMRT plans. Conclusions: The enhanced CT scans can be used for both target delineation and treatment planning in 3D-CRT. The dose difference caused by intravenous CA is small. But for SBRT and IMRT, the minimum irradiation dose in targets may be estimated to be increased up to 2.71% while the maximum dose may be estimated to be decreased up to 1.36%. However, the difference in dose distribution in most cases were found to be clinical tolerable.

  12. Computed tomography imaging parameters for inhomogeneity correction in radiation treatment planning

    Directory of Open Access Journals (Sweden)

    Indra J Das

    2016-01-01

    Full Text Available Modern treatment planning systems provide accurate dosimetry in heterogeneous media (such as a patient' body with the help of tissue characterization based on computed tomography (CT number. However, CT number depends on the type of scanner, tube voltage, field of view (FOV, reconstruction algorithm including artifact reduction and processing filters. The impact of these parameters on CT to electron density (ED conversion had been subject of investigation for treatment planning in various clinical situations. This is usually performed with a tissue characterization phantom with various density plugs acquired with different tube voltages (kilovoltage peak, FOV reconstruction and different scanners to generate CT number to ED tables. This article provides an overview of inhomogeneity correction in the context of CT scanning and a new evaluation tool, difference volume dose-volume histogram (DVH, dV-DVH. It has been concluded that scanner and CT parameters are important for tissue characterizations, but changes in ED are minimal and only pronounced for higher density materials. For lungs, changes in CT number are minimal among scanners and CT parameters. Dosimetric differences for lung and prostate cases are usually insignificant (<2% in three-dimensional conformal radiation therapy and < 5% for intensity-modulated radiation therapy (IMRT with CT parameters. It could be concluded that CT number variability is dependent on acquisition parameters, but its dosimetric impact is pronounced only in high-density media and possibly in IMRT. In view of such small dosimetric changes in low-density medium, the acquisition of additional CT data for financially difficult clinics and countries may not be warranted.

  13. Cone Beam Computed Tomography-Derived Adaptive Radiotherapy for Radical Treatment of Esophageal Cancer

    International Nuclear Information System (INIS)

    Hawkins, Maria A.; Brooks, Corrinne; Hansen, Vibeke N.; Aitken, Alexandra; Tait, Diana M.

    2010-01-01

    Purpose: To investigate the potential for reduction in normal tissue irradiation by creating a patient specific planning target volume (PTV) using cone beam computed tomography (CBCT) imaging acquired in the first week of radiotherapy for patients receiving radical radiotherapy. Methods and materials: Patients receiving radical RT for carcinoma of the esophagus were investigated. The PTV is defined as CTV(tumor, nodes) plus esophagus outlined 3 to 5 cm cranio-caudally and a 1.5-cm circumferential margin is added (clinical plan). Prefraction CBCT are acquired on Days 1 to 4, then weekly. No correction for setup error made. The images are imported into the planning system. The tumor and esophagus for the length of the PTV are contoured on each CBCT and 5 mm margin is added. A composite volume (PTV1) is created using Week 1 composite CBCT volumes. The same process is repeated using CBCT Week 2 to 6 (PTV2). A new plan is created using PTV1 (adaptive plan). The coverage of the 95% isodose of PTV1 is evaluated on PTV2. Dose-volume histograms (DVH) for lungs, heart, and cord for two plans are compared. Results: A total of 139 CBCT for 14 cases were analyzed. For the adaptive plan the coverage of the 95% prescription isodose for PTV1 = 95.6% ± 4% and the PTV2 = 96.8% ± 4.1% (t test, 0.19). Lungs V20 (15.6 Gy vs. 10.2 Gy) and heart mean dose (26.9 Gy vs. 20.7 Gy) were significantly smaller for the adaptive plan. Conclusions: A reduced planning volume can be constructed within the first week of treatment using CBCT. A single plan modification can be performed within the second week of treatment with considerable reduction in organ at risk dose.

  14. The use of 3D computer graphics in the diagnosis and treatment of spinal vascular malformations.

    Science.gov (United States)

    Takai, Keisuke; Kin, Taichi; Oyama, Hiroshi; Iijima, Akira; Shojima, Masaaki; Nishido, Hajime; Saito, Nobuhito

    2011-12-01

    Digital subtraction (DS) angiography is the gold standard for diagnosing spinal vascular malformations. Recently, multidetectorrow spiral CT and contrast-enhanced MR angiography have been introduced as screening examinations before DS angiography. These methods, however, do not always determine the accurate location of an arteriovenous shunt because the resulting images lack information about the spinal cord or the dura mater. Between April 2009 and December 2010, 13 patients underwent imaging evaluations for spinal vascular malformations at the authors' university hospital. This group included 8 patients with spinal dural arteriovenous fistulas (AVFs), 3 with perimedullary AVFs, and 2 with intramedullary arteriovenous malformations. Using data from these patients, the authors attempted to develop 3D computer graphics (CG) based upon the fusion of 3D rotational angiography and postmyelographic CT. They subsequently verified the accuracy of this imaging method. Ten of these 13 patients underwent surgical treatment for their lesions (11 AVFs), and for these 11 lesions the authors compared the diagnoses obtained using 3D CG with those obtained using conventional DS angiography. In all 13 cases, 3D CG images of the spinal lesions were successfully developed using the patients' actual data. Four (36%) of 11 AVFs were correctly identified using DS angiography, whereas 10 (91%) were correctly identified using 3D CG. Results from 3D CG of spinal AVFs corresponded well with operative findings, and 3D CG was significantly better than conventional DS angiography at predicting AVF location (p = 0.024, Fisher exact test). To the authors' knowledge, this is the first reported case series in which 3D CG of spinal vascular malformations was used to provide simultaneous, stereoscopic visualization of the spinal vascular system, spinal cord, dura mater, and bone. The 3D CG method provides precise visual images for the diagnosis and treatment of these lesions.

  15. A preoperative mathematic model for computed tomographic guided microwave ablation treatment of hepatic dome tumors.

    Science.gov (United States)

    Gao, Fei; Wang, Guo-Bao; Xiang, Zhan-Wang; Yang, Bin; Xue, Jing-Bing; Mo, Zhi-Qiang; Zhong, Zhi-Hui; Zhang, Tao; Zhang, Fu-Jun; Fan, Wei-Jun

    2016-05-03

    This study sought to prospectively evaluate the feasibility and safety of a preoperative mathematic model for computed tomographic(CT) guided microwave(MW) ablation treatment of hepatic dome tumors. This mathematic model was a regular cylinder quantifying appropriate puncture routes from the bottom up. A total of 103 patients with hepatic dome tumors were enrolled and randomly divided into 2 groups based on whether this model was used or not: Group A (using the model; n = 43) versus Group B (not using the model; n = 60). All tumors were treated by CT-guided MW ablation and follow-up contrast CT were reviewed. The average number of times for successful puncture, average ablation time, and incidence of right shoulder pain were less in Group A than Group B (1.4 vs. 2.5, P = 0.001; 8.8 vs. 11.1 minutes, P = 0.003; and 4.7% vs. 20%, P = 0.039). The technical success rate was higher in Group A than Group B (97.7% vs. 85.0%, P = 0.032). There were no significant differences between the two groups in primary and secondary technique efficacy rates (97.7% vs. 88.3%, P = 0.081; 90.0% vs. 72.7%, P = 0.314). No major complications occurred in both groups. The mathematic model of regular cylinder is feasible and safe for CT-guided MW ablation in treating hepatic dome tumors.

  16. Comparison of the pain levels of computer-controlled and conventional anesthesia techniques in prosthodontic treatment

    Directory of Open Access Journals (Sweden)

    Murat Yenisey

    2009-10-01

    Full Text Available OBJECTIVE: The objective of this study was to compare the pain levels on opposite sides of the maxilla at needle insertion during delivery of local anesthetic solution and tooth preparation for both conventional and anterior middle superior alveolar (AMSA technique with the Wand computer-controlled local anesthesia application. MATERIAL AND METHODS: Pain scores of 16 patients were evaluated with a 5-point verbal rating scale (VRS and data were analyzed nonparametrically. Pain differences at needle insertion, during delivery of local anesthetic, and at tooth preparation, for conventional versus the Wand technique, were analyzed using the Mann-Whitney U test (p=0.01. RESULTS: The Wand technique had a lower pain level compared to conventional injection for needle insertion (p0.05. CONCLUSIONS: The AMSA technique using the Wand is recommended for prosthodontic treatment because it reduces pain during needle insertion and during delivery of local anaesthetic. However, these two techniques have the same pain levels for tooth preparation.

  17. Influence of statin treatment on coronary atherosclerosis visualised using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Hans [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Klinikum Brandenburg, Department of Cardiology, Angiology, and Pulmonology, Brandenburg an der Havel (Germany); Frieler, Katja [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Medical Statistics, Berlin (Germany); Potsdam Institut fuer Klimaforschung, Potsdam (Germany); Schlattmann, Peter [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Medical Statistics, Berlin (Germany); Hamm, Bernd [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Dewey, Marc [Charite, Medical School, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Charite - Universitaetsmedizin Berlin, Freie Universitaet Berlin and Humboldt-Universitaet zu Berlin, Department of Radiology (Germany)

    2010-12-15

    Coronary angiography using multidetector computed tomography (MDCT) allows non-invasive assessment of non-calcified, calcified and mixed plaques. Progression of coronary plaques may be influenced by statins. Sixty-three consecutive patients underwent MDCT as a follow-up to their original CT angiography in a retrospective longitudinal study. MDCT was performed by using a voxel size of 0.5 x 0.35 x 0.35 mm{sup 3} at two time points 25 {+-} 3 months apart. Non-calcified, calcified and mixed coronary plaque components were analysed by using volumetric measurement. The influence of statin, low-density lipoprotein (LDL) and risk factors was assessed by using a linear random intercept model for plaque growth. The volumes of non-calcified, calcified and mixed coronary plaques significantly (P < 0.001) increased from baseline (medians/interquartile ranges = 21/15-39, 7/3-20 and 36/16-69 mm{sup 3}) to follow-up (29/17-44, 13/6-29 and 41/20-75 mm{sup 3}). Statins significantly slowed the growth of non-calcified plaques (statin coefficient {beta} = -0.0036, P = 0.01) but did not significantly affect the growth rate of mixed or calcified plaques. The effect of statin treatment on non-calcified plaques remained significant after adjusting for LDL levels and cardiac risk factors. Quantification using MDCT shows that progression of non-calcified coronary plaques may be slowed by statins. (orig.)

  18. Influence of statin treatment on coronary atherosclerosis visualised using multidetector computed tomography

    International Nuclear Information System (INIS)

    Hoffmann, Hans; Frieler, Katja; Schlattmann, Peter; Hamm, Bernd; Dewey, Marc

    2010-01-01

    Coronary angiography using multidetector computed tomography (MDCT) allows non-invasive assessment of non-calcified, calcified and mixed plaques. Progression of coronary plaques may be influenced by statins. Sixty-three consecutive patients underwent MDCT as a follow-up to their original CT angiography in a retrospective longitudinal study. MDCT was performed by using a voxel size of 0.5 x 0.35 x 0.35 mm 3 at two time points 25 ± 3 months apart. Non-calcified, calcified and mixed coronary plaque components were analysed by using volumetric measurement. The influence of statin, low-density lipoprotein (LDL) and risk factors was assessed by using a linear random intercept model for plaque growth. The volumes of non-calcified, calcified and mixed coronary plaques significantly (P 3 ) to follow-up (29/17-44, 13/6-29 and 41/20-75 mm 3 ). Statins significantly slowed the growth of non-calcified plaques (statin coefficient β = -0.0036, P = 0.01) but did not significantly affect the growth rate of mixed or calcified plaques. The effect of statin treatment on non-calcified plaques remained significant after adjusting for LDL levels and cardiac risk factors. Quantification using MDCT shows that progression of non-calcified coronary plaques may be slowed by statins. (orig.)

  19. Use of Positron Emission Tomography/Computed Tomography in Radiation Treatment Planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Kezban Berberoğlu

    2016-06-01

    Full Text Available Radiotherapy (RT plays an important role in the treatment of lung cancer. Accurate diagnosis and staging are crucial in the delivery of RT with curative intent. Target miss can be prevented by accurate determination of tumor contours during RT planning. Currently, tumor contours are determined manually by computed tomography (CT during RT planning. This method leads to differences in delineation of tumor volume between users. Given the change in RT tools and methods due to rapidly developing technology, it is now more significant to accurately delineate the tumor tissue. F18 fluorodeoxyglucose positron emission tomography/CT (F18 FDG PET/CT has been established as an accurate method in correctly staging and detecting tumor dissemination in lung cancer. Since it provides both anatomic and biologic information, F18 FDG PET decreases interuser variability in tumor delineation. For instance, tumor volumes may be decreased as atelectasis and malignant tissue can be more accurately differentiated, as well as better evaluation of benign and malignant lymph nodes given the difference in FDG uptake. Using F18 FDG PET/CT, the radiation dose can be escalated without serious adverse effects in lung cancer. In this study, we evaluated the contribution of F18 FDG PET/CT for RT planning in lung cancer.

  20. Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

    Science.gov (United States)

    Scripes, Paola G; Yaparpalvi, Ravindra

    2012-09-01

    The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Anisakiasis presenting to the ED: clinical manifestations, time course, hematologic tests, computed tomographic findings, and treatment.

    Science.gov (United States)

    Takabayashi, Takeshi; Mochizuki, Toshiaki; Otani, Norio; Nishiyama, Kei; Ishimatsu, Shinichi

    2014-12-01

    The prevalence of anisakiasis is rare in the United States and Europe compared with that in Japan, with few reports of its presentation in the emergency department (ED). This study describes the clinical, hematologic, computed tomographic (CT) characteristics, and treatment in gastric and small intestinal anisakiasis patients in the ED. We retrospectively reviewed the data of 83 consecutive anisakiasis presentations in our ED between 2003 and 2012. Gastric anisakiasis was endoscopically diagnosed with the Anisakis polypide. Small intestinal anisakiasis was diagnosed based on both hematologic (Anisakis antibody) and CT findings. Of the 83 cases, 39 had gastric anisakiasis and 44 had small intestinal anisakiasis based on our diagnostic criteria. Although all patients had abdominal pain, the gastric anisakiasis group developed symptoms significantly earlier (peaking within 6 hours) than the small intestinal anisakiasis group (peaking within 48 hours), and fewer patients with gastric anisakiasis needed admission therapy (5% vs 57%, Pfindings revealed edematous wall thickening in all patients, and ascites and phlegmon of the mesenteric fat were more frequently observed in the small intestinal anisakiasis group. In the ED, early and accurate diagnosis of anisakiasis is important to treat and explain to the patient, and diagnosis can be facilitated by a history of raw seafood ingestion, evaluation of the time-to-symptom development, and classic CT findings. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Optical coherence tomography based microangiography: A tool good for dermatology applications (Conference Presentation)

    Science.gov (United States)

    Wang, Ruikang K.; Baran, Utku; Choi, Woo J.

    2016-02-01

    Optical coherence tomography (OCT) based microangiography (OMAG) is a new imaging technique enabling the visualization of blood flow within microcirculatory tissue beds in vivo with high resolution. In this talk, the concept and advantages of OMAG will be discussed and its potential clinical applications in the dermatology will be shown, demonstrating its usefulness in the clinical monitoring and therapeutic treatment of various skin pathologies, e.g. acne, port wine stain and wound healing.

  3. Computer optimization of noncoplanar beam setups improves stereotactic treatment of liver tumors

    International Nuclear Information System (INIS)

    Pooter, Jacco A. de; Mendez Romero, Alejandra; Jansen, Wim; Storchi, Pascal; Woudstra, Evert; Levendag, Peter C.; Heijmen, Ben

    2006-01-01

    Purpose: To investigate whether computer-optimized fully noncoplanar beam setups may improve treatment plans for the stereotactic treatment of liver tumors. Methods: An algorithm for automated beam orientation and weight selection (Cycle) was extended for noncoplanar stereotactic treatments. For 8 liver patients previously treated in our clinic using a prescription isodose of 65%, Cycle was used to generate noncoplanar and coplanar plans with the highest achievable minimum planning target volume (PTV) dose for the clinically delivered isocenter and mean liver doses, while not violating the clinically applied hard planning constraints. The clinical and the optimized coplanar and noncoplanar plans were compared, with respect to D PTV,99% , the dose received by 99% of the PTV, the PTV generalized equivalent uniform dose (gEUD), and the compliance with the clinical constraints. Results: For each patient, the ratio between D PTV,99% and D isoc , and the gEUD -5 and gEUD -2 values of the optimized noncoplanar plan were higher than for the clinical plan with an average increase of respectively 18.8% (range, 7.8-24.0%), 6.4 Gy (range, 3.4-11.8 Gy), and 10.3 Gy (range, 6.7-12.5). D PTV,99% /D isoc , gEUD -5 , and gEUD -2 of the optimized noncoplanar plan was always higher than for the optimized coplanar plan with an average increase of, respectively, 4.5% (range, 0.2-9.7%), 2.7 Gy (range, 0.6-9.7 Gy), and 3.4 Gy (range, 0.6-9.9 Gy). All plans were within the imposed hard constraints. On average, the organs at risk were better spared with the optimized noncoplanar plan than with the optimized coplanar plan and the clinical plan. Conclusions: The use of automatically generated, fully noncoplanar beam setups results in plans that are favorable compared with coplanar techniques. Because of the automation, we found that the planning workload can be decreased from 1 to 2 days to 1 to 2 h

  4. Correlation of uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT)and treatment response in patients with knee pain

    International Nuclear Information System (INIS)

    Koh, Geon; Hwang, Kyung Hoon; Lee, Hae Jin; Kim, Seog Gyun; Lee, Beom Koo

    2016-01-01

    To determine whether treatment response in patients with knee pain could be predicted using uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT) images. Ninety-five patients with knee pain who had undergone SPECT/CT were included in this retrospective study. Subjects were divided into three groups: increased focal uptake (FTU), increased irregular tracer uptake (ITU), and no tracer uptake (NTU). A numeric rating scale (NRS-11) assessed pain intensity. We analyzed the association between uptake patterns and treatment response using Pearson's chi-square test and Fisher's exact test. Uptake was quantified from SPECT/CT with region of interest (ROI) counting, and an intraclass correlation coefficient (ICC) calculated agreement. We used Student' t-test to calculate statistically significant differences of counts between groups and the Pearson correlation to measure the relationship between counts and initial NRS-1k1. Multivariate logistic regression analysis determined which variables were significantly associated with uptake. The FTU group included 32 patients; ITU, 39; and NTU, 24. With conservative management, 64 % of patients with increased tracer uptake (TU, both focal and irregular) and 36 % with NTU showed positive response. Conservative treatment response of FTU was better than NTU, but did not differ from that of ITU. Conservative treatment response of TU was significantly different from that of NTU (OR 3.1; p 0.036). Moderate positive correlation was observed between ITU and initial NRS-11. Age and initial NRS-11 significantly predicted uptake. Patients with uptake in their knee(s) on SPECT/CT showed positive treatment response under conservative treatment

  5. Correlation of uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT)and treatment response in patients with knee pain

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Geon; Hwang, Kyung Hoon; Lee, Hae Jin; Kim, Seog Gyun; Lee, Beom Koo [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2016-06-15

    To determine whether treatment response in patients with knee pain could be predicted using uptake patterns on single-photon emission computed tomography/computed tomography (SPECT/CT) images. Ninety-five patients with knee pain who had undergone SPECT/CT were included in this retrospective study. Subjects were divided into three groups: increased focal uptake (FTU), increased irregular tracer uptake (ITU), and no tracer uptake (NTU). A numeric rating scale (NRS-11) assessed pain intensity. We analyzed the association between uptake patterns and treatment response using Pearson's chi-square test and Fisher's exact test. Uptake was quantified from SPECT/CT with region of interest (ROI) counting, and an intraclass correlation coefficient (ICC) calculated agreement. We used Student' t-test to calculate statistically significant differences of counts between groups and the Pearson correlation to measure the relationship between counts and initial NRS-1k1. Multivariate logistic regression analysis determined which variables were significantly associated with uptake. The FTU group included 32 patients; ITU, 39; and NTU, 24. With conservative management, 64 % of patients with increased tracer uptake (TU, both focal and irregular) and 36 % with NTU showed positive response. Conservative treatment response of FTU was better than NTU, but did not differ from that of ITU. Conservative treatment response of TU was significantly different from that of NTU (OR 3.1; p 0.036). Moderate positive correlation was observed between ITU and initial NRS-11. Age and initial NRS-11 significantly predicted uptake. Patients with uptake in their knee(s) on SPECT/CT showed positive treatment response under conservative treatment.

  6. Analysis of the multigroup model for muon tomography based threat detection

    Science.gov (United States)

    Perry, J. O.; Bacon, J. D.; Borozdin, K. N.; Fabritius, J. M.; Morris, C. L.

    2014-02-01

    We compare different algorithms for detecting a 5 cm tungsten cube using cosmic ray muon technology. In each case, a simple tomographic technique was used for position reconstruction, but the scattering angles were used differently to obtain a density signal. Receiver operating characteristic curves were used to compare images made using average angle squared, median angle squared, average of the squared angle, and a multi-energy group fit of the angular distributions for scenes with and without a 5 cm tungsten cube. The receiver operating characteristic curves show that the multi-energy group treatment of the scattering angle distributions is the superior method for image reconstruction.

  7. Analysis of the multigroup model for muon tomography based threat detection

    Energy Technology Data Exchange (ETDEWEB)

    Perry, J. O.; Bacon, J. D.; Borozdin, K. N.; Fabritius, J. M.; Morris, C. L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-14

    We compare different algorithms for detecting a 5 cm tungsten cube using cosmic ray muon technology. In each case, a simple tomographic technique was used for position reconstruction, but the scattering angles were used differently to obtain a density signal. Receiver operating characteristic curves were used to compare images made using average angle squared, median angle squared, average of the squared angle, and a multi-energy group fit of the angular distributions for scenes with and without a 5 cm tungsten cube. The receiver operating characteristic curves show that the multi-energy group treatment of the scattering angle distributions is the superior method for image reconstruction.

  8. Intraoperative cone-beam computed tomography and multi-slice computed tomography in temporal bone imaging for surgical treatment.

    Science.gov (United States)

    Erovic, Boban M; Chan, Harley H L; Daly, Michael J; Pothier, David D; Yu, Eugene; Coulson, Chris; Lai, Philip; Irish, Jonathan C

    2014-01-01

    Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens. Cross-sectional study. University tertiary care facility. Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures. CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus. CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

  9. The role of computed tomography in the diagnosis and treatment of hepatic abscess

    International Nuclear Information System (INIS)

    Kim, Ho Joon; Kim, So Sun; Huh, Jin Do; Chun, Byung Hee; Joh, Young Duk; Lee, Chung Han; Lee, Sung Do; Seo, Jae Kwan

    1988-01-01

    For the evaluation of the role of computed tomography in diagnosis and treatment of hepatic abscess, authors reviewed 50 computed tomographic scans in 45 patients of confirmed hepatic abscess retrospectively. The results were as follows 1. The hepatic abscesses were caused by pyogenic infections in 34 patients (76%), amebic infections in five (11%), mixed infections in six (13%), the most common bacteria responsible for infection were E-coli (53%). 2. Predisposing factors could be identified in 26 cases, including biliary tract disease, intraabdominal surgery, pancreatitis. 3. Multiple lesions were found in 48%. 4. Multiloculations within single cavity were present in 32%, in 2 cases, finer multiloculation was seen. 5. Calcification in the abscess wall was seen in 3 cases. 6. Previously reported 'highly suspected abscess findings' such as gas within lesion, rim enhancement and double target sign were seen in 14%, 26%, 6% respectively. 7. The CT appearance of hepatic abscess was variable, so we classified them 4 patterns. la type (30%): A hypodense central area surrounded by less hypodense zone were seen on precontrast scan. Following contrast media infusion, the central hypodense area became nonenhancing well defined hypodense area and the peripheral hypodense zone became isodense with liver parenchyma. lb type (8%): A hyphdense central area surrounded by less hypodense rim was seen on precontrast scan. Following contrast media infusion, they showed double target appearance. ll type (24%): Poorly defined gypodense area was seen on precontrast scan. Following contrast media infusion, the center of the hypodense area became a sell defined non-enhancing hypodense area, and the periphery of the lesion became isodense with liver parenchyma, so the lesion became smaller in size on post-contrast scan. lll type (38%): A relative well demarcated hypodense area on precontrast scan. Following contrast media infusion, they shows better demarcation and contrast with liver

  10. 3D and 4D magnetic susceptibility tomography based on complex MR images

    Science.gov (United States)

    Chen, Zikuan; Calhoun, Vince D

    2014-11-11

    Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.

  11. Electrical impedance tomography-based sensing skin for quantitative imaging of damage in concrete

    International Nuclear Information System (INIS)

    Hallaji, Milad; Pour-Ghaz, Mohammad; Seppänen, Aku

    2014-01-01

    This paper outlines the development of a large-area sensing skin for damage detection in concrete structures. The developed sensing skin consists of a thin layer of electrically conductive copper paint that is applied to the surface of the concrete. Cracking of the concrete substrate results in the rupture of the sensing skin, decreasing its electrical conductivity locally. The decrease in conductivity is detected with electrical impedance tomography (EIT) imaging. In previous works, electrically based sensing skins have provided only qualitative information on the damage on the substrate surface. In this paper, we study whether quantitative imaging of the damage is possible. We utilize application-specific models and computational methods in the image reconstruction, including a total variation (TV) prior model for the damage and an approximate correction of the modeling errors caused by the inhomogeneity of the painted sensing skin. The developed damage detection method is tested experimentally by applying the sensing skin to polymeric substrates and a reinforced concrete beam under four-point bending. In all test cases, the EIT-based sensing skin provides quantitative information on cracks and/or other damages on the substrate surface: featuring a very low conductivity in the damage locations, and a reliable indication of the lengths and shapes of the cracks. The results strongly support the applicability of the painted EIT-based sensing skin for damage detection in reinforced concrete elements and other substrates. (paper)

  12. Computational and Experimental Evaluations of a Novel Thermo-Brachytherapy Seed for Treatment of Solid Tumors

    Science.gov (United States)

    Warrell, Gregory R.

    of this seed was also quantified by Monte Carlo studies in the software package MCNP5. Experimental and computational analyses agree that the proposed seeds may heat a defined target with safe and attainable seed spacing and magnetic field parameters. These studies also point to the use of a ferrite-based ferrimagnetic core within the seeds, a design that would deliver hyperthermia of acceptable quality even for the high rate of blood perfusion in prostate tissue. The loss of radiation coverage due to the ISA effect of distributions of TB and HT-only seeds may be rectified by slightly increasing the prescribed dose in standard dose superposition-based treatment planning software. A systematic approach of combining LDR prostate brachytherapy with hyperthermia is thus described, and its ability to provide sufficient and uniform temperature distributions in realistic patient-specific implants evaluated. Potential improvements to the previously reported TB seed design are discussed based on quantitative evaluation of its operation and performance.

  13. Micro-tomography based Geometry Modeling of Three-Dimensional Braided Composites

    Science.gov (United States)

    Fang, Guodong; Chen, Chenghua; Yuan, Shenggang; Meng, Songhe; Liang, Jun

    2018-06-01

    A tracking and recognizing algorithm is proposed to automatically generate irregular cross-sections and central path of braid yarn within the 3D braided composites by using sets of high resolution tomography images. Only the initial cross-sections of braid yarns in a tomography image after treatment are required to be calibrated manually as searching cross-section template. The virtual geometry of 3D braided composites including some detailed geometry information, such as the braid yarn squeezing deformation, braid yarn distortion and braid yarn path deviation etc., can be reconstructed. The reconstructed geometry model can reflect the change of braid configurations during solidification process. The geometry configurations and mechanical properties of the braided composites are analyzed by using the reconstructed geometry model.

  14. Evaluation of safe surgical treatment of peritonsillar abscess using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Kasumi; Aramaki, Hajime; Arai, Yasuko; Uchimura, Kanako; Okabe, Kunihiko; Nishida, Motoko; Yoda, Keiko [Tokyo Women' s Medical Coll. (Japan). Daini Hospital

    2002-03-01

    With the development of new antimicrobial agents, the incidence of peritonsillar abscess (PTA) is on the decline. PTA is still often encountered in general practice, however, where it requires immediate diagnosis and treatment. Because the internal carotid artery runs medially to the medial parapharyngeal space, damage to nearby vascular or other structures is a surgical risk of PTA. We used contrast computed tomography (CT) from PTA patients to investigate the anatomical relationship between the abscess and parapharyngeal space, and to determine safe surgical sites. We observed 31 patients with PTA, 19 men and 12 women, between February 1997 and April 1999, all examined by contrast CT and undergoing drainage or incision. The average age was 30.7 years (range: 12-54 years). The abscess was on the right side in 20 cases and on the left side in 11. We determined the sites of the abscess and carotid artery, internal jugular vein, and surrounding soft tissue density area including nerves in the parapharyngeal space based on the angle and distance from recognizable anatomical structures in CT scans. The anterior margin of the parapharyngeal space was 29{+-}5 mm posterior from the upper posterior alveolar margin. The medial margin of that space was at 15{+-}2 deg laterally from the midline of the incisors, and 24{+-}4 mm laterally from the midline sagittal plane. The internal carotid artery was located medially to the parapharyngeal space, running on the sagittal plane containing the upper posterior alveolar margin. The distance from the anterior margin of the parapharyngeal space to the posterior wall of the PTA was 9{+-}4 mm, and the distance to the anterior wall of the abscess (including the pharyngeal mucosa) was 31{+-}5 cm. The relationship between the upper posterior alveolar margin and midline sagittal plane was useful for determining the site of the parapharyngeal space. Because the internal carotid artery is located on the same sagittal plane as the upper

  15. Evaluation of safe surgical treatment of peritonsillar abscess using computed tomography

    International Nuclear Information System (INIS)

    Ishii, Kasumi; Aramaki, Hajime; Arai, Yasuko; Uchimura, Kanako; Okabe, Kunihiko; Nishida, Motoko; Yoda, Keiko

    2002-01-01

    With the development of new antimicrobial agents, the incidence of peritonsillar abscess (PTA) is on the decline. PTA is still often encountered in general practice, however, where it requires immediate diagnosis and treatment. Because the internal carotid artery runs medially to the medial parapharyngeal space, damage to nearby vascular or other structures is a surgical risk of PTA. We used contrast computed tomography (CT) from PTA patients to investigate the anatomical relationship between the abscess and parapharyngeal space, and to determine safe surgical sites. We observed 31 patients with PTA, 19 men and 12 women, between February 1997 and April 1999, all examined by contrast CT and undergoing drainage or incision. The average age was 30.7 years (range: 12-54 years). The abscess was on the right side in 20 cases and on the left side in 11. We determined the sites of the abscess and carotid artery, internal jugular vein, and surrounding soft tissue density area including nerves in the parapharyngeal space based on the angle and distance from recognizable anatomical structures in CT scans. The anterior margin of the parapharyngeal space was 29±5 mm posterior from the upper posterior alveolar margin. The medial margin of that space was at 15±2 deg laterally from the midline of the incisors, and 24±4 mm laterally from the midline sagittal plane. The internal carotid artery was located medially to the parapharyngeal space, running on the sagittal plane containing the upper posterior alveolar margin. The distance from the anterior margin of the parapharyngeal space to the posterior wall of the PTA was 9±4 mm, and the distance to the anterior wall of the abscess (including the pharyngeal mucosa) was 31±5 cm. The relationship between the upper posterior alveolar margin and midline sagittal plane was useful for determining the site of the parapharyngeal space. Because the internal carotid artery is located on the same sagittal plane as the upper posterior

  16. Toward a web-based real-time radiation treatment planning system in a cloud computing environment.

    Science.gov (United States)

    Na, Yong Hum; Suh, Tae-Suk; Kapp, Daniel S; Xing, Lei

    2013-09-21

    To exploit the potential dosimetric advantages of intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), an in-depth approach is required to provide efficient computing methods. This needs to incorporate clinically related organ specific constraints, Monte Carlo (MC) dose calculations, and large-scale plan optimization. This paper describes our first steps toward a web-based real-time radiation treatment planning system in a cloud computing environment (CCE). The Amazon Elastic Compute Cloud (EC2) with a master node (named m2.xlarge containing 17.1 GB of memory, two virtual cores with 3.25 EC2 Compute Units each, 420 GB of instance storage, 64-bit platform) is used as the backbone of cloud computing for dose calculation and plan optimization. The master node is able to scale the workers on an 'on-demand' basis. MC dose calculation is employed to generate accurate beamlet dose kernels by parallel tasks. The intensity modulation optimization uses total-variation regularization (TVR) and generates piecewise constant fluence maps for each initial beam direction in a distributed manner over the CCE. The optimized fluence maps are segmented into deliverable apertures. The shape of each aperture is iteratively rectified to be a sequence of arcs using the manufacture's constraints. The output plan file from the EC2 is sent to the simple storage service. Three de-identified clinical cancer treatment plans have been studied for evaluating the performance of the new planning platform with 6 MV flattening filter free beams (40 × 40 cm(2)) from the Varian TrueBeam(TM) STx linear accelerator. A CCE leads to speed-ups of up to 14-fold for both dose kernel calculations and plan optimizations in the head and neck, lung, and prostate cancer cases considered in this study. The proposed system relies on a CCE that is able to provide an infrastructure for parallel and distributed computing. The resultant plans from the cloud computing are

  17. Toward a web-based real-time radiation treatment planning system in a cloud computing environment

    International Nuclear Information System (INIS)

    Na, Yong Hum; Kapp, Daniel S; Xing, Lei; Suh, Tae-Suk

    2013-01-01

    To exploit the potential dosimetric advantages of intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), an in-depth approach is required to provide efficient computing methods. This needs to incorporate clinically related organ specific constraints, Monte Carlo (MC) dose calculations, and large-scale plan optimization. This paper describes our first steps toward a web-based real-time radiation treatment planning system in a cloud computing environment (CCE). The Amazon Elastic Compute Cloud (EC2) with a master node (named m2.xlarge containing 17.1 GB of memory, two virtual cores with 3.25 EC2 Compute Units each, 420 GB of instance storage, 64-bit platform) is used as the backbone of cloud computing for dose calculation and plan optimization. The master node is able to scale the workers on an ‘on-demand’ basis. MC dose calculation is employed to generate accurate beamlet dose kernels by parallel tasks. The intensity modulation optimization uses total-variation regularization (TVR) and generates piecewise constant fluence maps for each initial beam direction in a distributed manner over the CCE. The optimized fluence maps are segmented into deliverable apertures. The shape of each aperture is iteratively rectified to be a sequence of arcs using the manufacture’s constraints. The output plan file from the EC2 is sent to the simple storage service. Three de-identified clinical cancer treatment plans have been studied for evaluating the performance of the new planning platform with 6 MV flattening filter free beams (40 × 40 cm 2 ) from the Varian TrueBeam TM STx linear accelerator. A CCE leads to speed-ups of up to 14-fold for both dose kernel calculations and plan optimizations in the head and neck, lung, and prostate cancer cases considered in this study. The proposed system relies on a CCE that is able to provide an infrastructure for parallel and distributed computing. The resultant plans from the cloud computing are

  18. Monitoring breast cancer treatment using a Fourier transform infrared spectroscopy-based computational model.

    Science.gov (United States)

    Depciuch, J; Kaznowska, E; Golowski, S; Koziorowska, A; Zawlik, I; Cholewa, M; Szmuc, K; Cebulski, J

    2017-09-05

    Breast cancer affects one in four women, therefore, the search for new diagnostic technologies and therapeutic approaches is of critical importance. This involves the development of diagnostic tools to facilitate the detection of cancer cells, which is useful for assessing the efficacy of cancer therapies. One of the major challenges for chemotherapy is the lack of tools to monitor efficacy during the course of treatment. Vibrational spectroscopy appears to be a promising tool for such a purpose, as it yields Fourier transformation infrared (FTIR) spectra which can be used to provide information on the chemical composition of the tissue. Previous research by our group has demonstrated significant differences between the infrared spectra of healthy, cancerous and post-chemotherapy breast tissue. Furthermore, the results obtained for three extreme patient cases revealed that the infrared spectra of post-chemotherapy breast tissue closely resembles that of healthy breast tissue when chemotherapy is effective (i.e., a good therapeutic response is achieved), or that of cancerous breast tissue when chemotherapy is ineffective. In the current study, we compared the infrared spectra of healthy, cancerous and post-chemotherapy breast tissue. Characteristic parameters were designated for the obtained spectra, spreading the function of absorbance using the Kramers-Kronig transformation and the best fit procedure to obtain Lorentz functions, which represent components of the bands. The Lorentz function parameters were used to develop a physics-based computational model to verify the efficacy of a given chemotherapy protocol in a given case. The results obtained using this model reflected the actual patient data retrieved from medical records (health improvement or no improvement). Therefore, we propose this model as a useful tool for monitoring the efficacy of chemotherapy in patients with breast cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Effectiveness of Computer-Based Treatment for Dyslexia in a Clinical Care Setting: Outcomes and Moderators

    Science.gov (United States)

    Tijms, Jurgen

    2011-01-01

    The clinical effectiveness of a treatment for children with dyslexia was examined, as well as the moderating impact of plausible cognitive and socio-economic factors on treatment success. Results revealed that the treatment group accrued significant greater gains than the control group in reading and spelling skills. The treatment group obtained a…

  20. Optimization of recommendations for abdomen computerized tomography based on reconstruction filters, voltage and tube current

    International Nuclear Information System (INIS)

    Silveira, Vinicius da Costa

    2015-01-01

    The use of computed tomography has increased significantly over the past decades. In Brazil the use increased more than twofold from 2008 to 2014, in the meantime the abdomen procedures have tripled. The high frequency of this procedure combined by the increasing collective radiation dose in medical exposures, has resulted development tools to maximize the benefit in CT images. This work aimed to establish protocols optimized in abdominal CT through acquisitions parameters and reconstructions techniques based on filters kernels. A sample of patients undergoing abdominal CT in a diagnostic center of Rio de Janeiro was assessed. Had been collected patients information and acquisitions parameters. The phantoms CT image acquisitions were performed by using different voltage values by adjusting the tube current (mAs) to obtain the same value from CTDI vol patients with normal BMI. Afterwards, the CTDIvol values were reduced by 30%, 50% and 60%. All images were reconstructed with low-contrast filters (A) and standard filters (B). The CTDIvol values for patients with normal BMI were 7% higher than in patients with underweight BMI and 30%, 50% and 60% lower than the overweight, obese I and III patients, respectively. The evaluations of image quality showed that variation of the current (mA) and the reconstruction filters did not affect the Hounsfield values. When the contrast-to-noise ratio (CNR) was normalized to CTDIvol, the protocols acquired with 60% reduction of CTDIvol with 140 kV and 80 kV showed CNR 6% lower than the routine. Modifications of the acquisition parameters did not affect spatial resolution, but the post-processing with B filters reduced the spatial frequency by 16%. With reduced the dose of 30%, lesions in the spleen had the CNR higher than 10% routine protocols with 140 kV acquired and post-processed to filter A. The image post-processing with a filter A with a 80kV voltage provided CNR values equal to the routine for the liver lesions with a 30

  1. Measurement of diabetic wounds with optical coherence tomography-based air-jet indentation system and a material testing system.

    Science.gov (United States)

    Choi, M-C; Cheung, K-K; Ng, G Y-F; Zheng, Y-P; Cheing, G L-Y

    2015-11-01

    Material testing system is a conventional but destructive method for measuring the biomechanical properties of wound tissues in basic research. The recently developed optical coherence tomography-based air-jet indentation system is a non-destructive method for measuring these properties of soft tissues in a non-contact manner. The aim of the study was to examine the correlation between the biomechanical properties of wound tissues measured by the two systems. Young male Sprague-Dawley rats with streptozotocin-induced diabetic were wounded by a 6 mm biopsy punch on their hind limbs. The biomechanical properties of wound tissues were assessed with the two systems on post-wounding days 3, 7, 10, 14, and 21. Wound sections were stained with picro-sirius red for analysis on the collagen fibres. Data obtained on the different days were charted to obtain the change in biomechanical properties across the time points, and then pooled to examine the correlation between measurements made by the two devices. Qualitative analysis to determine any correlation between indentation stiffness measured by the air-jet indentation system and the orientation of collagen fibres. The indentation stiffness is significantly negatively correlated to the maximum load, maximum tensile stress, and Young's modulus by the material testing system (all pair-jet indentation system to evaluate the biomechanical properties of wounds in a non-contact manner. It is a potential clinical device to examine the biomechanical properties of chronic wounds in vivo in a repeatable manner.

  2. Computer assisted treatments for image pattern data of laser plasma experiments

    International Nuclear Information System (INIS)

    Yaoita, Akira; Matsushima, Isao

    1987-01-01

    An image data processing system for laser-plasma experiments has been constructed. These image data are two dimensional images taken by X-ray, UV, infrared and visible light television cameras and also taken by streak cameras. They are digitized by frame memories. The digitized image data are stored in disk memories with the aid of a microcomputer. The data are processed by a host computer and stored in the files of the host computer and on magnetic tapes. In this paper, the over view of the image data processing system and some software for data handling in the host computer are reported. (author)

  3. SU-E-T-628: A Cloud Computing Based Multi-Objective Optimization Method for Inverse Treatment Planning.

    Science.gov (United States)

    Na, Y; Suh, T; Xing, L

    2012-06-01

    Multi-objective (MO) plan optimization entails generation of an enormous number of IMRT or VMAT plans constituting the Pareto surface, which presents a computationally challenging task. The purpose of this work is to overcome the hurdle by developing an efficient MO method using emerging cloud computing platform. As a backbone of cloud computing for optimizing inverse treatment planning, Amazon Elastic Compute Cloud with a master node (17.1 GB memory, 2 virtual cores, 420 GB instance storage, 64-bit platform) is used. The master node is able to scale seamlessly a number of working group instances, called workers, based on the user-defined setting account for MO functions in clinical setting. Each worker solved the objective function with an efficient sparse decomposition method. The workers are automatically terminated if there are finished tasks. The optimized plans are archived to the master node to generate the Pareto solution set. Three clinical cases have been planned using the developed MO IMRT and VMAT planning tools to demonstrate the advantages of the proposed method. The target dose coverage and critical structure sparing of plans are comparable obtained using the cloud computing platform are identical to that obtained using desktop PC (Intel Xeon® CPU 2.33GHz, 8GB memory). It is found that the MO planning speeds up the processing of obtaining the Pareto set substantially for both types of plans. The speedup scales approximately linearly with the number of nodes used for computing. With the use of N nodes, the computational time is reduced by the fitting model, 0.2+2.3/N, with r̂2>0.99, on average of the cases making real-time MO planning possible. A cloud computing infrastructure is developed for MO optimization. The algorithm substantially improves the speed of inverse plan optimization. The platform is valuable for both MO planning and future off- or on-line adaptive re-planning. © 2012 American Association of Physicists in Medicine.

  4. A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery

    Energy Technology Data Exchange (ETDEWEB)

    Aldosary, Ghada, E-mail: ghada.aldosary@mail.mcgill.ca [Medical Physics Unit, McGill University Health Centre, Montreal, Quebec (Canada); Nobah, Ahmad; Al-Zorkani, Faisal [Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Devic, Slobodan [Department of Radiation Oncology, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Moftah, Belal [Medical Physics Unit, McGill University Health Centre, Montreal, Quebec (Canada); Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)

    2015-01-01

    The effect of a treatment couch on dose perturbation is not always fully considered in intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). In the course of inverse planning radiotherapy techniques, beam parameter optimization may change in the absence of the couch, causing errors in the calculated dose distributions. Although modern treatment planning systems (TPS) include data for the treatment couch components, they are not manufactured identically. Thus, variations in their Hounsfield unit (HU) values may exist. Moreover, a radiotherapy facility may wish to have a third-party custom tabletop installed that is not included by the TPS vendor. This study demonstrates a practical and simple method of acquiring reliable computed tomography (CT) data for the treatment couch and shows how the absorbed dose calculated with the modeled treatment couch can differ from that with the default treatment couch found in the TPS. We also experimentally verified that neglecting to incorporate the treatment couch completely in the treatment planning process might result in dose differences of up to 9.5% and 7.3% for 4-MV and 10-MV photon beams, respectively. Furthermore, 20 RapidArc and IMRT cases were used to quantify the change in calculated dose distributions caused by using either the default or modeled couch. From 2-dimensional (2D) ionization chamber array measurements, we observed large dose distribution differences between the measurements and calculations when the couch was omitted that varied according to the planning technique and anatomic site. Thus, incorporating the treatment couch in the dose calculation phase of treatment planning significantly decreases dose calculation errors.

  5. Blunt oesophageal perforation: treatment with surgical exclusion and percutaneous drainage under computed tomographic guidance

    International Nuclear Information System (INIS)

    Vauthey, J.N.; Lerut, J.; Laube, M.; Gertsch, P.

    1992-01-01

    We report a patient with a left thoracic contusion and rupture of the distal oesophagus. Persistent sepsis developed after oesophageal exclusion without closure. Two collection were drained percutaneously under computed tomographic guidance and the sepsis resolved. (11 refs., 1 fig.)

  6. Computer simulation f the genetic controller for the EB flue gas treatment process

    International Nuclear Information System (INIS)

    Moroz, Z.; Bouzyk, J.; Sowinski, M.; Chmielewski, A.G.

    2001-01-01

    The use of computer genetic algorithm (GA) for driving a controller device for the industrial flue gas purification systems employing the electron beam irradiation, has been studied. As the mathematical model of the installation the properly trained artificial neural net (ANN) was used. Various cost functions and optimising strategies of the genetic code were tested. These computer simulations proved, that ANN + GA controller can be sufficiently precise and fast to be applied in real installations. (author)

  7. In Vivo Treatment Sensitivity Testing With Positron Emission Tomography/Computed Tomography After One Cycle of Chemotherapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin; Kostakoglu, Lale; Zaucha, Jan Maciej

    2014-01-01

    PURPOSE: Negative [(18)F]fluorodeoxyglucose (FDG) -positron emission tomography (PET)/computed tomography (CT) after two cycles of chemotherapy indicates a favorable prognosis in Hodgkin lymphoma (HL). We hypothesized that the negative predictive value would be even higher in patients responding....... In the absence of precise pretherapeutic predictive markers, PET1 is the best method for response-adapted strategies designed to select patients for less intensive treatment....

  8. Real-time computer treatment of THz passive device images with the high image quality

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2012-06-01

    We demonstrate real-time computer code improving significantly the quality of images captured by the passive THz imaging system. The code is not only designed for a THz passive device: it can be applied to any kind of such devices and active THz imaging systems as well. We applied our code for computer processing of images captured by four passive THz imaging devices manufactured by different companies. It should be stressed that computer processing of images produced by different companies requires using the different spatial filters usually. The performance of current version of the computer code is greater than one image per second for a THz image having more than 5000 pixels and 24 bit number representation. Processing of THz single image produces about 20 images simultaneously corresponding to various spatial filters. The computer code allows increasing the number of pixels for processed images without noticeable reduction of image quality. The performance of the computer code can be increased many times using parallel algorithms for processing the image. We develop original spatial filters which allow one to see objects with sizes less than 2 cm. The imagery is produced by passive THz imaging devices which captured the images of objects hidden under opaque clothes. For images with high noise we develop an approach which results in suppression of the noise after using the computer processing and we obtain the good quality image. With the aim of illustrating the efficiency of the developed approach we demonstrate the detection of the liquid explosive, ordinary explosive, knife, pistol, metal plate, CD, ceramics, chocolate and other objects hidden under opaque clothes. The results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem.

  9. Prescribed computer games in addition to occlusion versus standard occlusion treatment for childhood amblyopia: a pilot randomised controlled trial.

    Science.gov (United States)

    Tailor, Vijay K; Glaze, Selina; Khandelwal, Payal; Davis, Alison; Adams, Gillian G W; Xing, Wen; Bunce, Catey; Dahlmann-Noor, Annegret

    2015-01-01

    Amblyopia ("lazy eye") is the commonest vision deficit in children. If not fully corrected by glasses, amblyopia is treated by patching or blurring the better-seeing eye. Compliance with patching is often poor. Computer-based activities are increasingly topical, both as an adjunct to standard treatment and as a platform for novel treatments. Acceptability by families has not been explored, and feasibility of a randomised controlled trial (RCT) using computer games in terms of recruitment and treatment acceptability is uncertain. We carried out a pilot RCT to test whether computer-based activities are acceptable and accessible to families and to test trial methods such as recruitment and retention rates, randomisation, trial-specific data collection tools and analysis. The trial had three arms: standard near activity advice, Eye Five, a package developed for children with amblyopia, and an off-the-shelf handheld games console with pre-installed games. We enrolled 60 children age 3-8 years with moderate or severe amblyopia after completion of optical treatment. This trial was registered as UKCRN-ID 11074. Pre-screening of 3600 medical notes identified 189 potentially eligible children, of whom 60 remained eligible after optical treatment, and were enrolled between April 2012 and March 2013. One participant was randomised twice and withdrawn from the study. Of the 58 remaining, 37 were boys. The mean (SD) age was 4.6 (1.7) years. Thirty-seven had moderate and 21 severe amblyopia. Three participants were withdrawn at week 6, and in total, four were lost to follow-up at week 12. Most children and parents/carers found the study procedures, i.e. occlusion treatment, usage of the allocated near activity and completion of a study diary, easy. The prescribed cumulative dose of near activity was 84 h at 12 weeks. Reported near activity usage numbers were close to prescribed numbers in moderate amblyopes (94 % of prescribed) but markedly less in severe amblyopes (64

  10. Treatment of human-computer interface in a decision support system

    International Nuclear Information System (INIS)

    Heger, A.S.; Duran, F.A.; Cox, R.G.

    1992-01-01

    One of the most challenging applications facing the computer community is development of effective adaptive human-computer interface. This challenge stems from the complex nature of the human part of this symbiosis. The application of this discipline to the environmental restoration and waste management is further complicated due to the nature of environmental data. The information that is required to manage environmental impacts of human activity is fundamentally complex. This paper will discuss the efforts at Sandia National Laboratories in developing the adaptive conceptual model manager within the constraint of the environmental decision-making. A computer workstation, that hosts the Conceptual Model Manager and the Sandia Environmental Decision Support System will also be discussed

  11. Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

    Science.gov (United States)

    McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R

    To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations

  12. Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Schillaci, O. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Moroni, C. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Scopinaro, F. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Tavolaro, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Danieli, R. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy); Bossini, A. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Cassone, R. [Department of Internal Medicine, University ``La Sapienza``, Rome (Italy); Colella, A.C. [Section of Nuclear Medicine, Department of Experimental Medicine and Pathology, University ``La Sapienza``, Rome (Italy)

    1997-07-01

    The aim of this study was to evaluate the diagnostic capability of technetium-99m sestamibi tomography based on dipyridamole echocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercise electrocardiography and dipyridamole echocardiography. Forty subjects with mild to moderate hypertension, chest pain and no previous myocardial infarction were submitted to {sup 99m}Tc-sestamibi tomography (at rest and after high-dose dipyridamole echocardiography) and to exercise electrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease ({>=}70% stenosis of at least one major vessel) and 18 normal main coronary vessels (group B). Dipyridamole {sup 99m}Tc-sestamibi imaging was positive in 21/22 patients of group A and in 5/18 of group B. Dipyridamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/22 patients of group A and in 11/18 of group B. Four out of five subjects in group B with positive results in all the tests showed a slow run-off of angiographic contrast medium, probably due to small-vessel disease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole {sup 99m}Tc-sestamibi tomography is negative. When scintigraphy is positive, either epicardial coronary artery disease or a small-vessel disease condition is possible. The association of scintigraphy with dipyridamole echocardiography testing allows the assessment of contractile function and myocardial perfusion by a single pharmacological stress. (orig./AJ). With 3 figs., 2 tabs.

  13. Exploring the outcomes of a novel computer-assisted treatment program targeting expressive-grammar deficits in preschoolers with SLI.

    Science.gov (United States)

    Washington, Karla N; Warr-Leeper, Genese; Thomas-Stonell, Nancy

    2011-01-01

    The impact of a newly designed computer-assisted treatment (C-AT) program, My Sentence Builder, for the remediation of expressive-grammar deficits in children with specific language impairment (SLI) was explored. This program was specifically designed with features to directly address expressive-grammar difficulties, thought to be associated with hypothesized deficits in verbal working memory (VWM). Thirty-four preschoolers with deficits in expressive-grammar morphology participated. Using the randomization procedure of consecutive sampling, participants were recruited. Twenty-two participants were consecutively assigned to one of two treatment groups, C-AT or non C-AT (nC-AT). The nC-AT utilized conventional language stimulation procedures containing features which have been traditionally used to address expressive-grammar deficits. A group of equivalent children awaiting treatment and chosen from the same sample of children as the treatment participants served as a control group. Blind assessments of outcomes were completed pre-, post-, and 3-months post-treatment in a formal and informal context. C-AT and nC-AT participants significantly outperformed controls pre-to-post to 3-months post-treatment in both assessment contexts. No significant differences in treatment gains were found between C-AT and nC-AT. Results suggested that treatments designed to directly address expressive-grammar deficits were better than no treatment for preschool SLI. Further, use of a C-AT program may be another feasible treatment method for this disorder population. As a result of this activity, the reader will recognize that: (1) expressive-grammar treatment is better than no treatment for immediate and continued language growth, (2) use of a C-AT program containing specific features designed to directly address expressive-grammar deficits is another viable, but not necessarily a better treatment option for the remediation of expressive-grammar deficits in preschool children with SLI

  14. Computed tomography-guided bupivacaine and corticosteroid injection for the treatment of symptomatic calcification in the great toe tendon

    Directory of Open Access Journals (Sweden)

    Karatoprak O

    2014-04-01

    Full Text Available Omer Karatoprak,1 Sinan Karaca,2 Mehmet Nuri Erdem,3 Ozgur Karaman,2 Azmi Hamzaoglu41Department of Orthopedic Surgery, Kadikoy Florence Nightingale Hospital, Istanbul, Turkey; 2Department of Orthopedic Surgery, Fatih Sultan Mehmet Training and Research Hospital Atasehir, Istanbul, Turkey; 3Department of Orthopedics and Traumatology, Kolan International Hospital Sisli, Istanbul, Turkey; 4Department of Orthopedic Surgery, Istanbul Florence Nightingale Hospital, Istanbul TurkeyBackground: Calcification in the great toe tendon is a rare disorder that is characterized by the deposition of calcium on degenerative collagen fibrils.Case presentations: In this report, we present two cases of calcific tendonitis: one in the adductor hallucis and the other in the flexor hallucis longus tendon. We preferred computed tomography-guided steroid injection in our cases because of pain unresponsive to conservative treatment. Patients were free of symptoms at the follow-up visit, 4 weeks after injection.Conclusion: Calcification of the hallux tendons is a rare disorder. Treatment of tendonitis consists of nonsteroidal anti-inflammatory drugs. Local anesthetic and steroid injection may be considered in cases unresponsive to conservative treatment. Because of the anatomic location of tendons, injection could be difficult. Computed tomography guidance may improve the success rate of injections.Keywords: bupivacaine, calcification, great toe tendons, corticosteroid injection

  15. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array

    Energy Technology Data Exchange (ETDEWEB)

    O’Reilly, Meaghan A., E-mail: moreilly@sri.utoronto.ca; Jones, Ryan M. [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Birman, Gabriel [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Hynynen, Kullervo [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9 (Canada)

    2016-09-15

    Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  16. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array.

    Science.gov (United States)

    O'Reilly, Meaghan A; Jones, Ryan M; Birman, Gabriel; Hynynen, Kullervo

    2016-09-01

    Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  17. Comparison of Cone-Beam Computed Tomography and Periapical Radiography in Predicting Treatment Decision for Periapical Lesions: A Clinical Study

    Directory of Open Access Journals (Sweden)

    Ashok Balasundaram

    2012-01-01

    Full Text Available Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions’ projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1 measured lesion size and (2 made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ2(3=.036, P>0.05. Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.

  18. Application of computer-aided design osteotomy template for treatment of cubitus varus deformity in teenagers: a pilot study.

    Science.gov (United States)

    Zhang, Yuan Z; Lu, Sheng; Chen, Bin; Zhao, Jian M; Liu, Rui; Pei, Guo X

    2011-01-01

    Treatment of cubitus varus deformity from a malunited fracture is a challenge. Anatomically accurate correction is the key to obtaining good functional outcomes after corrective osteotomy. The aim of this study was to attempt to increase the accuracy of treatment by use of 3-dimensional (3D) computer-aided design. We describe a novel method for ensuring an accurate osteotomy method in the treatment of cubitus varus deformity in teenagers by means of 3D reconstruction and reverse engineering. Between January 2006 and May 2008, 12 male and 6 female patients with cubitus varus deformities underwent scanning with spiral computed tomography (CT) preoperatively. The mean age was 15.7 years, ranging from 13 to 19 years. Three-dimensional CT image data of the affected and contralateral normal bones of cubitus were transferred to a computer workstation. Three-dimensional models of cubitus were reconstructed by use of MIMICS software. The 3D models were then processed by Imageware software. An osteotomy template that best fitted the angle and range of osteotomy was "reversely" built from the 3D model. These templates were manufactured by a rapid prototyping machine. The osteotomy templates guide the osteotomy of cubitus. An accurate angle of osteotomy was confirmed by postoperative radiography. After 12 to 24 months' follow-up, the mean postoperative carrying angle in 18 patients with cubitus varus deformity was 7.3° (range, 5° to 11°), with a mean correction of 21.9° (range, 12° to 41°). The patient-specific template technique is easy to use, can simplify the surgical act, and generates highly accurate osteotomy in cubitus varus deformity in teenagers. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  19. Computer-aided Framework for Synthesis, Design and Retrofit of Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Bozkurt, Hande

    Water is used for several purposes in houses and industrial applications, which results in the generation of considerable amounts of wastewater. Wastewater should be handled appropriately which is required from legal, environmental as well as economic and societal perspectives. Wastewater treatment...... be formulated as a process synthesis challenge in the sense that a new taskcan be added to the existing treatment line or one or several existing processes can be changed as a result of the emerging needs. Existing plants need retrofitting due to a number of reasons such as: change in the wastewater flow...... plant (WWTP) design is a formidable challenge. One of the key steps involved is the process synthesis - defined as the selection of treatment processes as a combination of unit operations and processes to create the process flow diagram.As a consequence of the emerging technological developments...

  20. [Supportive amblyopia treatment by means of computer games with background stimulation; a placebo controlled pilot study of 10 days].

    Science.gov (United States)

    Kämpf, U; Muchamedjarow, F; Seiler, T

    2001-04-01

    Computer programmes for visual stimulation may give new impulses to the field of amblyopia treatment by offering an option to shift the apparative visual training into the domestic sphere. Regarding this aspect we report on a placebo controlled study on a newly developed vision training consisting of a background stimulation by a drifting sinusoidal grating combined with a foreground game aimed to maintain the attention. Fourteen amblyopia patients aged from 6 to 13 years participated in the study. Seven were allocated to a placebo and seven to a treatment group. Both groups had to train at the computer for a period of 10 working days by two sessions of about 20 minutes daily. Whilst the placebo group played in front of a neutral background, the treatment group did this with a drifting sinusoidal grating in the background. The treatment condition resulted in a greater increase of visual acuity than the placebo condition. Near vision improved in the treatment group from 0.20 (SD +/- 4.51 steps) to 0.39 (SD +/- 3.06 steps), i.e. by 3.0 steps of visual acuity (SD +/- 1.8 steps), in the placebo group from 0.14 (SD +/- 6.02 steps) to 0.17 (SD +/- 5.85 steps), i.e. by 0.8 steps of visual acuity (SD +/- 1.6 steps). Far vision improved in the treatment group from 0.29 (SD +/- 2.57 steps) to 0.44 (SD +/- 3.16 steps), i.e. by 1.9 steps of visual acuity (SD +/- 1.3 steps), in the placebo group from 0.24 (SD +/- 5.20 steps) to 0.28 (SD +/- 5.51 steps), i.e. by 0.7 steps of visual acuity (SD +/- 1.1 steps). Stimulation with drifting sinusoidal gratings improves the visual acuity of amblyopic eyes in a specific way. The effect might be accounted for by a synergy of spatial and temporal frequency in form vs. motion channels. A preliminary hypothesis is discussed and will be the subject of ongoing research. The presented method has been developed for the treatment of "delayed" amblyopia in the elder child. It is aimed to support and complement occlusion therapy. However, the

  1. Novel diode-based laser system for combined transcutaneous monitoring and computer-controlled intermittent treatment of jaundiced neonates

    Science.gov (United States)

    Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

    2001-06-01

    The high efficacy of laser phototherapy combined with transcutaneous monitoring of serum bilirubin provides optimum safety for jaundiced infants from the risk of bilirubin encephalopathy. In this paper the authors introduce the design and operating principles of a new laser system that can provide simultaneous monitoring and treatment of several jaundiced babies at one time. The new system incorporates diode-based laser sources oscillating at selected wavelengths to achieve both transcutaneous differential absorption measurements of bilirubin concentration in addition to the computer controlled intermittent laser therapy through a network of optical fibers. The detailed description and operating characteristics of this system are presented.

  2. Large-scale computational drug repositioning to find treatments for rare diseases.

    Science.gov (United States)

    Govindaraj, Rajiv Gandhi; Naderi, Misagh; Singha, Manali; Lemoine, Jeffrey; Brylinski, Michal

    2018-01-01

    Rare, or orphan, diseases are conditions afflicting a small subset of people in a population. Although these disorders collectively pose significant health care problems, drug companies require government incentives to develop drugs for rare diseases due to extremely limited individual markets. Computer-aided drug repositioning, i.e., finding new indications for existing drugs, is a cheaper and faster alternative to traditional drug discovery offering a promising venue for orphan drug research. Structure-based matching of drug-binding pockets is among the most promising computational techniques to inform drug repositioning. In order to find new targets for known drugs ultimately leading to drug repositioning, we recently developed e MatchSite, a new computer program to compare drug-binding sites. In this study, e MatchSite is combined with virtual screening to systematically explore opportunities to reposition known drugs to proteins associated with rare diseases. The effectiveness of this integrated approach is demonstrated for a kinase inhibitor, which is a confirmed candidate for repositioning to synapsin Ia. The resulting dataset comprises 31,142 putative drug-target complexes linked to 980 orphan diseases. The modeling accuracy is evaluated against the structural data recently released for tyrosine-protein kinase HCK. To illustrate how potential therapeutics for rare diseases can be identified, we discuss a possibility to repurpose a steroidal aromatase inhibitor to treat Niemann-Pick disease type C. Overall, the exhaustive exploration of the drug repositioning space exposes new opportunities to combat orphan diseases with existing drugs. DrugBank/Orphanet repositioning data are freely available to research community at https://osf.io/qdjup/.

  3. Treatment of early and late reflections in a hybrid computer model for room acoustics

    DEFF Research Database (Denmark)

    Naylor, Graham

    1992-01-01

    The ODEON computer model for acoustics in large rooms is intended for use both in design (by predicting room acoustical indices quickly and easily) and in research (by forming the basis of an auralization system and allowing study of various room acoustical phenomena). These conflicting demands...... preclude the use of both ``pure'' image source and ``pure'' particle tracing methods. A hybrid model has been developed, in which rays discover potential image sources up to a specified order. Thereafter, the same ray tracing process is used in a different way to rapidly generate a dense reverberant decay...

  4. Stochastic methods for uncertainty treatment of functional variables in computer codes: application to safety studies

    International Nuclear Information System (INIS)

    Nanty, Simon

    2015-01-01

    This work relates to the framework of uncertainty quantification for numerical simulators, and more precisely studies two industrial applications linked to the safety studies of nuclear plants. These two applications have several common features. The first one is that the computer code inputs are functional and scalar variables, functional ones being dependent. The second feature is that the probability distribution of functional variables is known only through a sample of their realizations. The third feature, relative to only one of the two applications, is the high computational cost of the code, which limits the number of possible simulations. The main objective of this work was to propose a complete methodology for the uncertainty analysis of numerical simulators for the two considered cases. First, we have proposed a methodology to quantify the uncertainties of dependent functional random variables from a sample of their realizations. This methodology enables to both model the dependency between variables and their link to another variable, called co-variate, which could be, for instance, the output of the considered code. Then, we have developed an adaptation of a visualization tool for functional data, which enables to simultaneously visualize the uncertainties and features of dependent functional variables. Second, a method to perform the global sensitivity analysis of the codes used in the two studied cases has been proposed. In the case of a computationally demanding code, the direct use of quantitative global sensitivity analysis methods is intractable. To overcome this issue, the retained solution consists in building a surrogate model or meta model, a fast-running model approximating the computationally expensive code. An optimized uniform sampling strategy for scalar and functional variables has been developed to build a learning basis for the meta model. Finally, a new approximation approach for expensive codes with functional outputs has been

  5. Quantum computation and analysis of Wigner and Husimi functions: toward a quantum image treatment.

    Science.gov (United States)

    Terraneo, M; Georgeot, B; Shepelyansky, D L

    2005-06-01

    We study the efficiency of quantum algorithms which aim at obtaining phase-space distribution functions of quantum systems. Wigner and Husimi functions are considered. Different quantum algorithms are envisioned to build these functions, and compared with the classical computation. Different procedures to extract more efficiently information from the final wave function of these algorithms are studied, including coarse-grained measurements, amplitude amplification, and measure of wavelet-transformed wave function. The algorithms are analyzed and numerically tested on a complex quantum system showing different behavior depending on parameters: namely, the kicked rotator. The results for the Wigner function show in particular that the use of the quantum wavelet transform gives a polynomial gain over classical computation. For the Husimi distribution, the gain is much larger than for the Wigner function and is larger with the help of amplitude amplification and wavelet transforms. We discuss the generalization of these results to the simulation of other quantum systems. We also apply the same set of techniques to the analysis of real images. The results show that the use of the quantum wavelet transform allows one to lower dramatically the number of measurements needed, but at the cost of a large loss of information.

  6. Use of Respiratory-Correlated Four-Dimensional Computed Tomography to Determine Acceptable Treatment Margins for Locally Advanced Pancreatic Adenocarcinoma

    International Nuclear Information System (INIS)

    Goldstein, Seth D.; Ford, Eric C.; Duhon, Mario; McNutt, Todd; Wong, John; Herman, Joseph M.

    2010-01-01

    Purpose: Respiratory-induced excursions of locally advanced pancreatic adenocarcinoma could affect dose delivery. This study quantified tumor motion and evaluated standard treatment margins. Methods and Materials: Respiratory-correlated four-dimensional computed tomography images were obtained on 30 patients with locally advanced pancreatic adenocarcinoma; 15 of whom underwent repeat scanning before cone-down treatment. Treatment planning software was used to contour the gross tumor volume (GTV), bilateral kidneys, and biliary stent. Excursions were calculated according to the centroid of the contoured volumes. Results: The mean ± standard deviation GTV excursion in the superoinferior (SI) direction was 0.55 ± 0.23 cm; an expansion of 1.0 cm adequately accounted for the GTV motion in 97% of locally advanced pancreatic adenocarcinoma patients. Motion GTVs were generated and resulted in a 25% average volume increase compared with the static GTV. Of the 30 patients, 17 had biliary stents. The mean SI stent excursion was 0.84 ± 0.32 cm, significantly greater than the GTV motion. The xiphoid process moved an average of 0.35 ± 0.12 cm, significantly less than the GTV. The mean SI motion of the left and right kidneys was 0.65 ± 0.27 cm and 0.77 ± 0.30 cm, respectively. At repeat scanning, no significant changes were seen in the mean GTV size (p = .8) or excursion (p = .3). Conclusion: These data suggest that an asymmetric expansion of 1.0, 0.7, and 0.6 cm along the respective SI, anteroposterior, and medial-lateral directions is recommended if a respiratory-correlated four-dimensional computed tomography scan is not available to evaluate the tumor motion during treatment planning. Surrogates of tumor motion, such as biliary stents or external markers, should be used with caution.

  7. 77: Development, utilization and evolution of a computer system for treatment follow-up and medical management of a radiotherapy department

    International Nuclear Information System (INIS)

    Costa, A.; Leca, M.; Marcie, S.; Rameau, P.; Lagrange, J.L.; Chauvel, P.; Hery, M.; Lalanne, C.M.

    1987-01-01

    SISGRAD, a computer system developed in the Radiotherapy Dept. of the Centre A. Lacassagne, has been operational for 5 years. This network of microcomputers is connected to the computers used for dosimetry, and is integrated in the hospital's general computer system. SISGRAD was designed primarily to verify that prescribed irradiation treatments are given properly and to improve medical and administrative management of the Dept. SISGRAD is also utilized to provide information to data bases. 22 refs.; 2 figs.; 1 table

  8. Oral omega-3 fatty acids treatment in computer vision syndrome related dry eye.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi; Phogat, Hemant; Kaur, Avinash; Kumar, Manjushri

    2015-06-01

    To assess the efficacy of dietary consumption of omega-3 fatty acids (O3FAs) on dry eye symptoms, Schirmer test, tear film break up time (TBUT) and conjunctival impression cytology (CIC) in patients with computer vision syndrome. Interventional, randomized, double blind, multi-centric study. Four hundred and seventy eight symptomatic patients using computers for more than 3h per day for minimum 1 year were randomized into two groups: 220 patients received two capsules of omega-3 fatty acids each containing 180mg eicosapentaenoic acid (EPA) and 120mg docosahexaenoic acid (DHA) daily (O3FA group) and 236 patients received two capsules of a placebo containing olive oil daily for 3 months (placebo group). The primary outcome measure was improvement in dry eye symptoms and secondary outcome measures were improvement in Nelson grade and an increase in Schirmer and TBUT scores at 3 months. In the placebo group, before dietary intervention, the mean symptom score, Schirmer, TBUT and CIC scores were 7.5±2, 19.9±4.7mm, 11.5±2s and 1±0.9 respectively, and 3 months later were 6.8±2.2, 20.5±4.7mm, 12±2.2s and 0.9±0.9 respectively. In the O3FA group, these values were 8.0±2.6, 20.1±4.2mm, 11.7±1.6s and 1.2±0.8 before dietary intervention and 3.9±2.2, 21.4±4mm, 15±1.7s, 0.5±0.6 after 3 months of intervention, respectively. This study demonstrates the beneficial effect of orally administered O3FAs in alleviating dry eye symptoms, decreasing tear evaporation rate and improving Nelson grade in patients suffering from computer vision syndrome related dry eye. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. Improved Optimization for Wastewater Treatment and Reuse System Using Computational Intelligence

    Directory of Open Access Journals (Sweden)

    Zong Woo Geem

    2018-01-01

    Full Text Available River water pollution by wastewater can cause significant negative impact on the aquatic sustainability. Hence, accurate modeling of this complicated system and its cost-effective treatment and reuse decision is very important because this optimization process is related to economic expenditure, societal health, and environmental deterioration. In order to optimize this complex system, we may consider three treatment or reuse options such as microscreening filtration, nitrification, and fertilization-oriented irrigation on top of two existing options such as settling and biological oxidation. The objective of this environmental optimization is to minimize the economic expenditure of life cycle costs while satisfying the public health standard in terms of groundwater quality and the environmental standard in terms of river water quality. Particularly, this study improves existing optimization model by pinpointing the critical deficit location of dissolved oxygen sag curve by using analytic differentiation. Also, the proposed formulation considers more practical constraints such as maximal size of irrigation area and minimal amount of filtration treatment process. The results obtained by using an evolutionary algorithm, named a parameter-setting-free harmony search algorithm, show that the proposed model successfully finds optimal solutions while conveniently locating the critical deficit point.

  10. Improvements in Thermal Performance of Mango Hot-water Treatment Equipments: Data Analysis, Mathematical Modelling and Numerical-computational Simulation

    Directory of Open Access Journals (Sweden)

    Elder M. Mendoza Orbegoso

    2017-06-01

    Full Text Available Mango is one of the most popular and best paid tropical fruits in worldwide markets, its exportation is regulated within a phytosanitary quality control for killing the “fruit fly”. Thus, mangoes must be subject to hot-water treatment process that involves their immersion in hot water over a period of time. In this work, field measurements, analytical and simulation studies are developed on available hot-water treatment equipment called “Original” that only complies with United States phytosanitary protocols. These approaches are made to characterize the fluid-dynamic and thermal behaviours that occur during the mangoes’ hot-water treatment process. Then, analytical model and Computational fluid dynamics simulations are developed for designing new hot-water treatment equipment called “Hybrid” that simultaneously meets with both United States and Japan phytosanitary certifications. Comparisons of analytical results with data field measurements demonstrate that “Hybrid” equipment offers a better fluid-dynamic and thermal performance than “Original” ones.

  11. 4D computed tomography scans for conformal thoracic treatment planning: is a single scan sufficient to capture thoracic tumor motion?

    Science.gov (United States)

    Tseng, Yolanda D.; Wootton, Landon; Nyflot, Matthew; Apisarnthanarax, Smith; Rengan, Ramesh; Bloch, Charles; Sandison, George; St. James, Sara

    2018-01-01

    Four dimensional computed tomography (4DCT) scans are routinely used in radiation therapy to determine the internal treatment volume for targets that are moving (e.g. lung tumors). The use of these studies has allowed clinicians to create target volumes based upon the motion of the tumor during the imaging study. The purpose of this work is to determine if a target volume based on a single 4DCT scan at simulation is sufficient to capture thoracic motion. Phantom studies were performed to determine expected differences between volumes contoured on 4DCT scans and those on the evaluation CT scans (slow scans). Evaluation CT scans acquired during treatment of 11 patients were compared to the 4DCT scans used for treatment planning. The images were assessed to determine if the target remained within the target volume determined during the first 4DCT scan. A total of 55 slow scans were compared to the 11 planning 4DCT scans. Small differences were observed in phantom between the 4DCT volumes and the slow scan volumes, with a maximum of 2.9%, that can be attributed to minor differences in contouring and the ability of the 4DCT scan to adequately capture motion at the apex and base of the motion trajectory. Larger differences were observed in the patients studied, up to a maximum volume difference of 33.4%. These results demonstrate that a single 4DCT scan is not adequate to capture all thoracic motion throughout treatment.

  12. Computed tomography diagnosis of neonatal hypoxic ischemic encephalopathy combined with intracranial hemorrhage and clinical nursing treatment.

    Science.gov (United States)

    Zhang, Y; Zhang, J L; Li, Y

    2016-01-01

    Hypoxic ischemic encephalopathy (HIE), one of the common causes of newborn invalidism, is likely to induce nervous system-associated sequelae and even intracranial hemorrhage in severe cases. The incidence rate of HIE has been rising in recent years. In order to study the clinical nursing effect for HIE combined with intracranial hemorrhage, 76 newborns diagnosed with HIE combined with intracranial hemorrhage by spiral computed tomography (CT) from the of Binzhou People’s Hospital, Shandong, China were selected. They were divided into a control group and an intervention group. The control group received routine nursing, while the intervention group received comprehensive nursing intervention. The experimental results suggested that the mental developmental index (MDI) value and the psychomotor developmental index (PDI) value of patients in the intervention group were much higher than those of the control group and the difference was significant (phemorrhage recover more effectively, therefore is worth applying.

  13. Poster — Thur Eve — 69: Computational Study of DVH-guided Cancer Treatment Planning Optimization Methods

    Energy Technology Data Exchange (ETDEWEB)

    Ghomi, Pooyan Shirvani; Zinchenko, Yuriy [University of Calgary, Department of Mathematics and Statistics (Canada)

    2014-08-15

    Purpose: To compare methods to incorporate the Dose Volume Histogram (DVH) curves into the treatment planning optimization. Method: The performance of three methods, namely, the conventional Mixed Integer Programming (MIP) model, a convex moment-based constrained optimization approach, and an unconstrained convex moment-based penalty approach, is compared using anonymized data of a prostate cancer patient. Three plans we generated using the corresponding optimization models. Four Organs at Risk (OARs) and one Tumor were involved in the treatment planning. The OARs and Tumor were discretized into total of 50,221 voxels. The number of beamlets was 943. We used commercially available optimization software Gurobi and Matlab to solve the models. Plan comparison was done by recording the model runtime followed by visual inspection of the resulting dose volume histograms. Conclusion: We demonstrate the effectiveness of the moment-based approaches to replicate the set of prescribed DVH curves. The unconstrained convex moment-based penalty approach is concluded to have the greatest potential to reduce the computational effort and holds a promise of substantial computational speed up.

  14. [Application of computer-aided osteotomy template design in treatment of developmental dysplasia of the hip with steel osteotomy].

    Science.gov (United States)

    Tong, Kuang; Zhang, Yuanzhi; Zhang, Sheng; Yu, Bin

    2013-06-01

    To provide an accurate method for osteotomy in the treatment of developmental dysplasia of the hip with steel osteotomy by three-dimensional reconstruction and Reverse Engineering technique. Between January 2011 and December 2012, 13 children with developmental dysplasia of the hip underwent steel osteotomy. 3D CT scan pelvic images were obtained and transferred via a DICOM network into a computer workstation to construct 3D models of the hip using Materialise Mimics 14.1 software in STL format. These models were imported into Imageware 12.0 software for steel osteotomy simulation until a stable hip was attained in the anatomical position for dislocation or subluxation of the hip in older children. The osteotomy navigational templates were designed according to the anatomical features after a stable hip was reconstructed. These navigational templates were manufactured using a rapid prototyping technique. The reconstruction hips in these children show good matching property and acetabulum cover. The computer-aided design of osteotomy template provides personalized and accurate solutions in the treatment of developmental dysplasia of the hip with steel osteotomy in older children.

  15. Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer.

    NARCIS (Netherlands)

    Schinagl, D.A.X.; Vogel, W.V.; Hoffmann, A.L.; Dalen, J.A. van; Oyen, W.J.G.; Kaanders, J.H.A.M.

    2007-01-01

    PURPOSE: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may

  16. Computer-aided beam arrangement based on similar cases in radiation treatment-planning databases for stereotactic lung radiation therapy

    International Nuclear Information System (INIS)

    Magome, Taiki; Shioyama, Yoshiyuki; Arimura, Hidetaka

    2013-01-01

    The purpose of this study was to develop a computer-aided method for determination of beam arrangements based on similar cases in a radiotherapy treatment-planning database for stereotactic lung radiation therapy. Similar-case-based beam arrangements were automatically determined based on the following two steps. First, the five most similar cases were searched, based on geometrical features related to the location, size and shape of the planning target volume, lung and spinal cord. Second, five beam arrangements of an objective case were automatically determined by registering five similar cases with the objective case, with respect to lung regions, by means of a linear registration technique. For evaluation of the beam arrangements five treatment plans were manually created by applying the beam arrangements determined in the second step to the objective case. The most usable beam arrangement was selected by sorting the five treatment plans based on eight plan evaluation indices, including the D95, mean lung dose and spinal cord maximum dose. We applied the proposed method to 10 test cases, by using an RTP database of 81 cases with lung cancer, and compared the eight plan evaluation indices between the original treatment plan and the corresponding most usable similar-case-based treatment plan. As a result, the proposed method may provide usable beam arrangements, which have no statistically significant differences from the original beam arrangements (P>0.05) in terms of the eight plan evaluation indices. Therefore, the proposed method could be employed as an educational tool for less experienced treatment planners. (author)

  17. Artificial intelligence in medicine and cardiac imaging: harnessing big data and advanced computing to provide personalized medical diagnosis and treatment.

    Science.gov (United States)

    Dilsizian, Steven E; Siegel, Eliot L

    2014-01-01

    Although advances in information technology in the past decade have come in quantum leaps in nearly every aspect of our lives, they seem to be coming at a slower pace in the field of medicine. However, the implementation of electronic health records (EHR) in hospitals is increasing rapidly, accelerated by the meaningful use initiatives associated with the Center for Medicare & Medicaid Services EHR Incentive Programs. The transition to electronic medical records and availability of patient data has been associated with increases in the volume and complexity of patient information, as well as an increase in medical alerts, with resulting "alert fatigue" and increased expectations for rapid and accurate diagnosis and treatment. Unfortunately, these increased demands on health care providers create greater risk for diagnostic and therapeutic errors. In the near future, artificial intelligence (AI)/machine learning will likely assist physicians with differential diagnosis of disease, treatment options suggestions, and recommendations, and, in the case of medical imaging, with cues in image interpretation. Mining and advanced analysis of "big data" in health care provide the potential not only to perform "in silico" research but also to provide "real time" diagnostic and (potentially) therapeutic recommendations based on empirical data. "On demand" access to high-performance computing and large health care databases will support and sustain our ability to achieve personalized medicine. The IBM Jeopardy! Challenge, which pitted the best all-time human players against the Watson computer, captured the imagination of millions of people across the world and demonstrated the potential to apply AI approaches to a wide variety of subject matter, including medicine. The combination of AI, big data, and massively parallel computing offers the potential to create a revolutionary way of practicing evidence-based, personalized medicine.

  18. Dynamic Computational Model of Symptomatic Bacteremia to Inform Bacterial Separation Treatment Requirements.

    Directory of Open Access Journals (Sweden)

    Sinead E Miller

    Full Text Available The rise of multi-drug resistance has decreased the effectiveness of antibiotics, which has led to increased mortality rates associated with symptomatic bacteremia, or bacterial sepsis. To combat decreasing antibiotic effectiveness, extracorporeal bacterial separation approaches have been proposed to capture and separate bacteria from blood. However, bacteremia is dynamic and involves host-pathogen interactions across various anatomical sites. We developed a mathematical model that quantitatively describes the kinetics of pathogenesis and progression of symptomatic bacteremia under various conditions, including bacterial separation therapy, to better understand disease mechanisms and quantitatively assess the biological impact of bacterial separation therapy. Model validity was tested against experimental data from published studies. This is the first multi-compartment model of symptomatic bacteremia in mammals that includes extracorporeal bacterial separation and antibiotic treatment, separately and in combination. The addition of an extracorporeal bacterial separation circuit reduced the predicted time of total bacteria clearance from the blood of an immunocompromised rodent by 49%, compared to antibiotic treatment alone. Implementation of bacterial separation therapy resulted in predicted multi-drug resistant bacterial clearance from the blood of a human in 97% less time than antibiotic treatment alone. The model also proposes a quantitative correlation between time-dependent bacterial load among tissues and bacteremia severity, analogous to the well-known 'area under the curve' for characterization of drug efficacy. The engineering-based mathematical model developed may be useful for informing the design of extracorporeal bacterial separation devices. This work enables the quantitative identification of the characteristics required of an extracorporeal bacteria separation device to provide biological benefit. These devices will potentially

  19. The application of positron emission tomography/computed tomography in radiation treatment planning: effect on gross target volume definition and treatment management.

    Science.gov (United States)

    Iğdem, S; Alço, G; Ercan, T; Unalan, B; Kara, B; Geceer, G; Akman, C; Zengin, F O; Atilla, S; Okkan, S

    2010-04-01

    To analyse the effect of the use of molecular imaging on gross target volume (GTV) definition and treatment management. Fifty patients with various solid tumours who underwent positron emission tomography (PET)/computed tomography (CT) simulation for radiotherapy planning from 2006 to 2008 were enrolled in this study. First, F-18 fluorodeoxyglucose (FDG)-PET and CT scans of the treatment site in the treatment position and then a whole body scan were carried out with a dedicated PET/CT scanner and fused thereafter. FDG-avid primary tumour and lymph nodes were included into the GTV. A multidisciplinary team defined the target volume, and contouring was carried out by a radiation oncologist using visual methods. To compare the PET/CT-based volumes with CT-based volumes, contours were drawn on CT-only data with the help of site-specific radiologists who were blind to the PET/CT results after a median time of 7 months. In general, our PET/CT volumes were larger than our CT-based volumes. This difference was significant in patients with head and neck cancers. Major changes (> or =25%) in GTV delineation were observed in 44% of patients. In 16% of cases, PET/CT detected incidental second primaries and metastatic disease, changing the treatment strategy from curative to palliative. Integrating functional imaging with FDG-PET/CT into the radiotherapy planning process resulted in major changes in a significant proportion of our patients. An interdisciplinary approach between imaging and radiation oncology departments is essential in defining the target volumes. Copyright 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  20. Computational fluid dynamics simulations of membrane filtration process adapted for water treatment of aerated sewage lagoons.

    Science.gov (United States)

    Cano, Grégory; Mouahid, Adil; Carretier, Emilie; Guasp, Pascal; Dhaler, Didier; Castelas, Bernard; Moulin, Philippe

    2015-01-01

    The aim of this study is to apply the membrane bioreactor technology in an oxidation ditch in submerged conditions. This new wastewater filtration process will benefit rural areas (membranes developed without support are immersed in an aeration well and work in suction mode. The development of the membrane without support and more precisely the performance of spacers are approached by computational fluid dynamics in order to provide the best compromise between pressure drop/flow velocity and permeate flux. The numerical results on the layout and the membrane modules' geometry in the aeration well indicate that the optimal configuration is to install the membranes horizontally on three levels. Membranes should be connected to each other to a manifold providing a total membrane area of 18 m². Loss rate compared to the theoretical throughput is relatively low (less than 3%). Preliminary data obtained by modeling the lagoon provide access to its hydrodynamics, revealing that recirculation zones can be optimized by making changes in the operating conditions. The experimental validation of these results and taking into account the aeration in the numerical models are underway.

  1. Surgical treatment of progressive ethmoidal hematoma aided by computed tomography in a foal

    International Nuclear Information System (INIS)

    Colbourne, C.M.; Rosenstein, D.S.; Steficek, B.A.; Yovich, J.V.; Stick, J.A.

    1997-01-01

    A progressive ethmoidal hematoma (PEH) was treated successfully in a 4-week-old Belgian filly by surgical removal, using a frontonasal bone flap. The filly had respiratory stridor, epistaxis, and facial enlargement over the left paranasal sinuses, which had progressively increased in size since birth. Computed tomographic images of the head obtained with the foal under general anesthesia were useful in determining the extent and nature of the soft-tissue mass and planning surgical intervention. On the basis of the histologic appearance of the mass, a diagnosis of PEH was made. Twelve months after surgery, the facial appearance was normal and the abnormal appearance of the ethmoid region on endoscopic evaluation was less obvious, with return of the nasal septum to a normal position. Progressive ethmoidal hematoma is uncommon and, to our knowledge, has not been reported in a neonate. Clinical signs of PEH in this foal were atypical because of the rapid enlargement of the mass, extent of facial deformity, and minimal epistaxis and interoperative hemorrhage

  2. Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sveistrup, Joen, E-mail: joensveistrup@hotmail.com [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Loft, Annika [PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Berthelsen, Anne Kiil [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Henriksen, Birthe Merete; Nielsen, Michael Bachmann [Department of Radiology, Section of Ultrasound X4123, Rigshospitalet, Copenhagen (Denmark); Engelholm, Svend Aage [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark)

    2012-05-01

    Purpose: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. Methods and Materials: Ninety-five (95) patients referred to our clinic between July 1, 2005, and December 31, 2009, were retrospectively reviewed. All patients had biopsy-proven primary squamous cell cancer of the anal canal. There were 65 females (68%) and 30 males (32%), and the median age was 58 years (range, 35-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT. Results: Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal nodes on PET/CT that had not been seen on US. One of these was malignant, three were benign, and six were not biopsied. PET/CT diagnosed eight metastatic sites, whereas TAUS/US diagnosed three. PET/CT discovered three of the five synchronous cancers seen in this study. PET/CT upstaged the disease in 14% of the cases and changed the treatment plan proposed by TAUS/US in 17%. Conclusion: PET/CT has great potential influence on the staging and treatment of anal cancer. TAUS is important in the staging of the primary tumor and N1-stage, whereas PET/CT seems necessary for the N2/3-stage, the M-stage and synchronous cancers.

  3. Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer

    DEFF Research Database (Denmark)

    Sveistrup, Joen; Loft, Annika; Berthelsen, Anne Kiil

    2012-01-01

    PURPOSE: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. METHODS......-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT. RESULTS: Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized...... on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal...

  4. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort.

    Science.gov (United States)

    Mah, K; Danjoux, C E; Manship, S; Makhani, N; Cardoso, M; Sixel, K E

    1998-07-15

    To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of > or =5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization.

  5. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort

    International Nuclear Information System (INIS)

    Mah, Katherine; Danjoux, Cyril E.; Manship, Sharan; Makhani, Nadiya; Cardoso, Marlene; Sixel, Katharina E.

    1998-01-01

    Purpose: To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. Methods and Materials: A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Results: Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was <10 min in all cases. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of ≥5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Conclusions: Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall

  6. Nonoperative treatment of splenic trauma: usefulness of computed tomography; Tratamento conservador do trauma esplenico: utilidade da tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Resende, Vivian [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Medicina; Tavares Junior, Wilson Campos; Vieira, Jose Nelson Mendes [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Dept. de Radiologia e Diagnostico por Imagem]. E-mail: wilsontavaresjrmd@yahoo.fr; Drumond, Domingos Andre Fernandes [Hospital Joao XXIII, Belo Horizonte, MG (Brazil). Setor de Clinica Cirurgica

    2005-04-15

    Objective: to report the results of use of conservative treatment in patients with splenic trauma and to emphasize the usefulness of computed tomography in these cases. Material and method: sixty-nine cases of pediatric patients with blunt abdominal trauma seen from from January 2001 to June 2004 at the level I trauma center were retrospectively studied. Forty-four of these patients were submitted to nonoperative treatment and the clinical follow-up was performed by computerized tomography. All patients had been diagnosed with splenic injury by computerized tomography.Results: the causes of the injuries were motor vehicle accident in 12 (27.2%) patients, bicycle accident in nine (20.4%) patients, and falls in 23 (52.2%) patients. Two (3.7%) patients died from associated injuries. The mean duration of hospital stay was six days. The mean age of the patients was nine years. Conclusion: conservative treatment for blunt splenic trauma is performed with the aim of reducing costs and risks for the patients, and computerized tomography should be routinely used. No posterior complications were observed in this approach. (author)

  7. Single photon emission computed tomography before and after treatment of anxiety using a selective serotonin reuptake inhibitor

    International Nuclear Information System (INIS)

    Warwick, J.M.; Heerden, B.B. van; Stein, D.J.; Niehaus, D.J.H.; Seedat, S.; Linden, G. van der; Harvey, B.A.

    2002-01-01

    Background: The selective serotonin reuptake inhibitors (SSRIs) are currently recommended as first line medications for a number of different anxiety disorders, including obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and social anxiety disorder (social phobia) (SAD). This raises the question of what effects these agents have on the functional neuroanatomy of anxiety disorders. Methods: Single photon emission computed tomography (SPECT) brain scanning was undertaken in patients with OCD, PTSD, and SAD before and after treatment with citalopram, the most selective of the SSRIs. Statistical parametric mapping (SPM) was used to compare scans (pre- vs post-medication, and responders vs nonresponders) in the combined group of subjects. Results: Citalopram pharmacotherapy resulted in significant deactivation within anterior and superior cingulate and left hippocampus. Deactivation within the anterior cingulate, left paracingular cortex, and right inferior frontal cortex was more marked in treatment responders. Baseline activation did not, however, predict response to pharmacotherapy. Conclusion: Although each of the anxiety disorders may be mediated by different neurocircuits, there are some overlaps in the functional neuroanatomy of their response to SSRI treatment. The current data is consistent with previous work demonstrating the importance of limbic circuits in this spectrum of disorders. These play a crucial role in cognitive-affective processing, and are innervated by serotonergic neurons

  8. Development of a prototype mesoscale computer model incorporating treatment of topography

    International Nuclear Information System (INIS)

    Apsimon, H.M.; Goddard, A.J.H.; Kitson, K.; Fawcett, M.

    1985-01-01

    More sophisticated models are now available to simulate dispersal of accidental radioactive releases to the atmosphere; these use mass-consistent windfields and attempt allowance for site-specific topographical features. Our aim has been to examine these techniques critically, develop where possible, and assess limitations and accuracy. The resulting windfield model WAFT uses efficient numerical techniques with improved orographic resolution and treatment of meteorological conditions. Time integrated air concentrations, dry and wet deposition are derived from TOMCATS, which applies Monte-Carlo techniques to an assembly of pseudo-particles representing the release, with specific attention to the role of large eddies and evolving inhomogeneous rainfields. These models have been assessed by application to hypothetical releases in complex terrain using data which would have been available in the event of an accident, and undertaking sensitivity studies. It is concluded that there is considerable uncertainty in results produced by such models; although they may be useful in post-facto analysis, such limitations cast doubt on their advantages relative to simpler techniques, with more modest requirements, during an actual emergency. (author)

  9. Computer Aided Medical Diagnosis for the Treatment of Sexually Transmitted Disease (Gonorrhea

    Directory of Open Access Journals (Sweden)

    Adamu M. Ibrahim

    2017-02-01

    Full Text Available The World Health Organization (WHO report on the circumstances of clinical facilities in developing countries indicates that, there is considerable efficient delivery of medical services to the rural inhabitants where the services are available, these services are very expensive and not affordable to the average citizen. This has risen inadequacies such as prolonged suffering and even death. The slow process of diagnosis trial and error of diseases can be disastrous when a patient is at the advanced stage of a disease. Here we propose an automated system that can aid the diagnosis of sexually transmitted diseases and suggest adequate drug prescriptions and treatment. To achieve this, an extensive review on related diseases were reevaluated and a common type (gonorrhea was used as an exemplary study. This is based on the Structure Systems Analysis and Design Methodology (SSADM. The paper as shown a system that is most effective and have a fast way of diagnosing and treating sexually transmitted diseases, which serves as a great relief for the doctors and even non-experts in the field.

  10. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients

    DEFF Research Database (Denmark)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. METHODS...... AND MATERIALS: Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT...

  11. Computed tomography or necropsy diagnosis of multiple bullae and the treatment of pneumothorax in rhesus macaques (Macaca mulatta).

    Science.gov (United States)

    Kim, Jong-Min; Han, Sungyoung; Shin, Jun-Seop; Min, Byoung-Hoon; Jeong, Won Young; Lee, Ga Eul; Kim, Min Sun; Kim, Ju Eun; Chung, Hyunwoo; Park, Chung-Gyu

    2017-10-01

    Pulmonary bullae and pneumothorax have various etiologies in veterinary medicine. We diagnosed multiple pulmonary bullae combined with or without pneumothorax by computed tomography (CT) or necropsy in seven rhesus macaques (Macaca mulatta) imported from China. Two of seven rhesus macaques accompanied by pneumothorax were cured by fixation of ruptured lung through left or right 3rd intercostal thoracotomy. Pneumonyssus simicola, one of the etiologies of pulmonary bullae, was not detected from tracheobronchiolar lavage. To the best of our knowledge, this is the first case report on the CT-aided diagnosis of pulmonary bullae and the successful treatment of combined pneumothorax by thoracotomy in non-human primates (NHPs). © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Technical progress, the concept of individualized cancer treatment and the innovation of computer-assisted radiotherapy planning

    International Nuclear Information System (INIS)

    Merkle, K.; Tanneberger, S.; Matschke, S.

    1985-01-01

    After a first step of cancerogenesis, the further development of the tumor is an individual process. At the end of this process the tumor is formed as an individual in the individual. The individuality of cancer exists on the level of organs, tissues and cells and includes an individual tumor-host relationship. Today, optimized cancer treatment requires a most precise biological characterization possible of the tumor and of the tumor-host relationship, which will provide objective information about the individual character of every tumor. Routine analysis and strict therapeutic consideration of the clinical and biological individuality of human cancer can offer real chances for the improvement of cancer treatment. A routine acquisition of individual tumor characteristics will be possible only if methods and equipment are available for the registration of suitable parameters. In this context technical innovations have an essential influence on the realization of the concept of individualized cancer treatment. With the method of flow cytophotometry and other techniques examples are given in how far the ideas of individual cancer management can be realized by introduction of new technical solutions into medical research and clinical practice. Unfortunately there is still a lack of methodology in individualizing cancer treatment. The individualization of radiotherapy is connected to an extremely high degree of technical innovations. Particularly this refers to the topometrical description of the target volume in relation to the adjacent anatomical structures and the body contour as well as the fitting of isodoses to the shape and size of the target volume. As an example of innovation of a technical solution for individual radiotherapy planning the computer-assisted radiotherapy planning system DOPSY is described. (author)

  13. Influence of Heat Treatment of Nickel-Titanium Rotary Endodontic Instruments on Apical Preparation: A Micro-Computed Tomographic Study.

    Science.gov (United States)

    de Almeida, Bernardo Corrêa; Ormiga, Fabíola; de Araújo, Marcos César Pimenta; Lopes, Ricardo Tadeu; Lima, Inayá Corrêa Barbosa; dos Santos, Bernardo Camargo; Gusman, Heloisa

    2015-12-01

    The aim of this study was to make a 3-dimensional comparison of the canal transportation and changes in apical geometry using micro-computed tomographic imaging after canal preparation with K3 (SybronEndo, Orange, CA) and K3XF (SybronEndo) file systems. Twenty-eight mandibular molars were randomly divided into 2 groups according to the rotary system used in instrumentation: K3 or K3XF. The specimens were scanned by micro-computed tomographic imaging before and after instrumentation. Images before and after instrumentation from each group were compared with regard to canal volume, surface area, and structure model index (SMI) (paired t test, P instrumentation, the canals from each group were compared regarding the changes in volume, surface area, SMI, and canal transportation in the last 4 apical mm (t test, P Instrumentation with the 2 rotary systems significantly changed the canal volume, surface area, and SMI (P instrument types concerning these parameters (P > .05). There were no significant differences between the 2 groups with regard to canal transportation in the last 4 apical mm (P > .05). Both rotary systems showed adequate canal preparations with reduced values of canal transportation. Heat treatment did not influence changes in root canal geometry in the apical region. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Computational tools for the construction of calibration curves for use in dose calculations in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Oliveira, Alex C.H.; Vieira, Jose W.; Escola Politecnica de Pernambuco , Recife, PE

    2011-01-01

    The realization of tissue inhomogeneity corrections in image-based treatment planning improves the accuracy of radiation dose calculations for patients undergoing external-beam radiotherapy. Before the tissue inhomogeneity correction can be applied, the relationship between the computed tomography (CT) numbers and density must be established. This relationship is typically established by a calibration curve empirically obtained from CT images of a phantom that has several inserts of tissue-equivalent materials, covering a wide range of densities. This calibration curve is scanner-dependent and allows the conversion of CT numbers in densities for use in dose calculations. This paper describes the implementation of computational tools necessary to construct calibration curves. These tools are used for reading and displaying of CT images in DICOM format, determination of the mean CT numbers (and their standard deviations) of each tissue-equivalent material and construction of calibration curves by fits with bilinear equations. All these tools have been implemented in the Microsoft Visual Studio 2010 in C≠ programming language. (author)

  15. The effect of influent temperature variations in a sedimentation tank for potable water treatment--a computational fluid dynamics study.

    Science.gov (United States)

    Goula, Athanasia M; Kostoglou, Margaritis; Karapantsios, Thodoris D; Zouboulis, Anastasios I

    2008-07-01

    A computational fluid dynamics (CFD) model is used to assess the effect of influent temperature variation on solids settling in a sedimentation tank for potable water treatment. The model is based on the CFD code Fluent and exploits several specific aspects of the potable water application to derive a computational tool much more efficient than the corresponding tools employed to simulate primary and secondary wastewater settling tanks. The linearity of the particle conservation equations allows separate calculations for each particle size class, leading to the uncoupling of the CFD problem from a particular inlet particle size distribution. The usually unknown and difficult to be measured particle density is determined by matching the theoretical to the easily measured experimental total settling efficiency. The present model is adjusted against data from a real sedimentation tank and then it is used to assess the significance of influent temperature variation. It is found that a temperature difference of only 1 degrees C between influent and tank content is enough to induce a density current. When the influent temperature rises, the tank exhibits a rising buoyant plume that changes the direction of the main circular current. This process keeps the particles in suspension and leads to a higher effluent suspended solids concentration, thus, worse settling. As the warmer water keeps coming in, the temperature differential decreases, the current starts going back to its original position, and, thus, the suspended solids concentration decreases.

  16. Application of an EPID for fast daily dosimetric quality control of a fully computer-controlled treatment unit

    International Nuclear Information System (INIS)

    Dirkx, M.L.P.; Kroonwijk, M.; De Boer, J.C.J.; Heijmen, B.J.M.

    1995-01-01

    The MM50 Racetrack Microtron, suited for sophisticated three-dimensional computer-controlled conformal radiotherapy techniques, is a complex treatment unit in various respects. Therefore, for a number of gantry angles, daily quality control of the absolute output and the profiles of the scanned photon beams in mandatory. A fast method for these daily checks, based on dosimetric measurements with the Philips SRI-100 Electronic Portal Imaging Device, has been developed and tested. Open beams are checked for four different gantry angles; for gantry angle 0, a wedged field is checked as well. The fields are set up one after another under full computer control. Performing and analyzing the measurements takes about ten minutes. The applied EPID has favourable characteristics for dosimetric quality control measurements: absolute measurements reproduce within 0.5% (1 SD) and the reproducibility of a relative (2-D) fluence profile is 0.2% (1 SD). The day-to-day sensitivity stability over a period of a month is 0.6% (1 SD). EPID-signals are within 0.2% linear with the applied dose. The 2-D fluence profile of the 25 MV photon beam of the MM50 is very stable in time: during a period of one year, a maximum fluctuation of 2.6% was observed. Once, a deviation in the cGy/MU-value of 6% was detected. Only because of the performed morning quality control checks with the EPID, erroneous dose delivery to patients could be avoided; there is no interlock in the MM50-system that would have prevented patient treatment. Based on our experiences and on clinical requirements regarding the acceptability of deviations of beam characteristics, a protocol has been developed including action levels for additional investigations. Studies on the application of the SRI-100 for in vivo dosimetry on the MM50 have been started

  17. Application of an EPID for fast daily dosimetric quality control of a fully computer-controlled treatment unit

    Energy Technology Data Exchange (ETDEWEB)

    Dirkx, M L.P.; Kroonwijk, M; De Boer, J C.J.; Heijmen, B J.M. [Nederlands Kanker Inst. ` Antoni van Leeuwenhoekhuis` , Amsterdam (Netherlands)

    1995-12-01

    The MM50 Racetrack Microtron, suited for sophisticated three-dimensional computer-controlled conformal radiotherapy techniques, is a complex treatment unit in various respects. Therefore, for a number of gantry angles, daily quality control of the absolute output and the profiles of the scanned photon beams in mandatory. A fast method for these daily checks, based on dosimetric measurements with the Philips SRI-100 Electronic Portal Imaging Device, has been developed and tested. Open beams are checked for four different gantry angles; for gantry angle 0, a wedged field is checked as well. The fields are set up one after another under full computer control. Performing and analyzing the measurements takes about ten minutes. The applied EPID has favourable characteristics for dosimetric quality control measurements: absolute measurements reproduce within 0.5% (1 SD) and the reproducibility of a relative (2-D) fluence profile is 0.2% (1 SD). The day-to-day sensitivity stability over a period of a month is 0.6% (1 SD). EPID-signals are within 0.2% linear with the applied dose. The 2-D fluence profile of the 25 MV photon beam of the MM50 is very stable in time: during a period of one year, a maximum fluctuation of 2.6% was observed. Once, a deviation in the cGy/MU-value of 6% was detected. Only because of the performed morning quality control checks with the EPID, erroneous dose delivery to patients could be avoided; there is no interlock in the MM50-system that would have prevented patient treatment. Based on our experiences and on clinical requirements regarding the acceptability of deviations of beam characteristics, a protocol has been developed including action levels for additional investigations. Studies on the application of the SRI-100 for in vivo dosimetry on the MM50 have been started.

  18. Computer Enabled Neuroplasticity Treatment: a Clinical Trial of a Novel Design for Neurofeedback Therapy in Adult ADHD

    Directory of Open Access Journals (Sweden)

    Benjamin eCowley

    2016-05-01

    analysis will be reported elsewhere.Trial RegistrationComputer Enabled Neuroplasticity Treatment (CENT, ISRCTN13915109.Partly funded by Finnish science agency TEKES, project #440078.

  19. Treatment planning for a small animal using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Chow, James C. L.; Leung, Michael K. K.

    2007-01-01

    The development of a small animal model for radiotherapy research requires a complete setup of customized imaging equipment, irradiators, and planning software that matches the sizes of the subjects. The purpose of this study is to develop and demonstrate the use of a flexible in-house research environment for treatment planning on small animals. The software package, called DOSCTP, provides a user-friendly platform for DICOM computed tomography-based Monte Carlo dose calculation using the EGSnrcMP-based DOSXYZnrc code. Validation of the treatment planning was performed by comparing the dose distributions for simple photon beam geometries calculated through the Pinnacle3 treatment planning system and measurements. A treatment plan for a mouse based on a CT image set by a 360-deg photon arc is demonstrated. It is shown that it is possible to create 3D conformal treatment plans for small animals with consideration of inhomogeneities using small photon beam field sizes in the diameter range of 0.5-5 cm, with conformal dose covering the target volume while sparing the surrounding critical tissue. It is also found that Monte Carlo simulation is suitable to carry out treatment planning dose calculation for small animal anatomy with voxel size about one order of magnitude smaller than that of the human

  20. TH-AB-202-03: A Novel Tool for Computing Deliverable Doses in Dynamic MLC Tracking Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Fast, M; Kamerling, C; Menten, M; Nill, S; Oelfke, U [The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London (United Kingdom); Crijns, S; Raaymakers, B [University Medical Center Utrecht, Utrecht (Netherlands)

    2016-06-15

    Purpose: In tracked dynamic multi-leaf collimator (MLC) treatments, segments are continuously adapted to the target centroid motion in beams-eye-view. On-the-fly segment adaptation, however, potentially induces dosimetric errors due to the finite MLC leaf width and non-rigid target motion. In this study, we outline a novel tool for computing the 4d dose of lung SBRT plans delivered with MLC tracking. Methods: The following automated workflow was developed: A) centroid tracking, where the initial segments are morphed to each 4dCT phase based on the beams-eye-view GTV shift (followed by a dose calculation on each phase); B) re-optimized tracking, in which all morphed initial plans from (A) are further optimised (“warm-started”) in each 4dCT phase using the initial optimisation parameters but phase-specific volume definitions. Finally, both dose sets are accumulated to the reference phase using deformable image registration. Initial plans were generated according to the RTOG-1021 guideline (54Gy, 3-Fx, equidistant 9-beam IMRT) on the peak-exhale (reference) phase of a phase-binned 4dCT. Treatment planning and delivery simulations were performed in RayStation (research v4.6) using our in-house segment-morphing algorithm, which directly links to RayStation through a native C++ interface. Results: Computing the tracking plans and 4d dose distributions via the in-house interface takes 5 and 8 minutes respectively for centroid and re-optimized tracking. For a sample lung SBRT patient with 14mm peak-to-peak motion in sup-inf direction, mainly perpendicular leaf motion (0-collimator) resulted in small dose changes for PTV-D95 (−13cGy) and GTV-D98 (+18cGy) for the centroid tracking case compared to the initial plan. Modest reductions of OAR doses (e.g. spinal cord D2: −11cGy) were achieved in the idealized tracking case. Conclusion: This study presents an automated “1-click” workflow for computing deliverable MLC tracking doses in RayStation. Adding a non

  1. TH-AB-202-03: A Novel Tool for Computing Deliverable Doses in Dynamic MLC Tracking Treatments

    International Nuclear Information System (INIS)

    Fast, M; Kamerling, C; Menten, M; Nill, S; Oelfke, U; Crijns, S; Raaymakers, B

    2016-01-01

    Purpose: In tracked dynamic multi-leaf collimator (MLC) treatments, segments are continuously adapted to the target centroid motion in beams-eye-view. On-the-fly segment adaptation, however, potentially induces dosimetric errors due to the finite MLC leaf width and non-rigid target motion. In this study, we outline a novel tool for computing the 4d dose of lung SBRT plans delivered with MLC tracking. Methods: The following automated workflow was developed: A) centroid tracking, where the initial segments are morphed to each 4dCT phase based on the beams-eye-view GTV shift (followed by a dose calculation on each phase); B) re-optimized tracking, in which all morphed initial plans from (A) are further optimised (“warm-started”) in each 4dCT phase using the initial optimisation parameters but phase-specific volume definitions. Finally, both dose sets are accumulated to the reference phase using deformable image registration. Initial plans were generated according to the RTOG-1021 guideline (54Gy, 3-Fx, equidistant 9-beam IMRT) on the peak-exhale (reference) phase of a phase-binned 4dCT. Treatment planning and delivery simulations were performed in RayStation (research v4.6) using our in-house segment-morphing algorithm, which directly links to RayStation through a native C++ interface. Results: Computing the tracking plans and 4d dose distributions via the in-house interface takes 5 and 8 minutes respectively for centroid and re-optimized tracking. For a sample lung SBRT patient with 14mm peak-to-peak motion in sup-inf direction, mainly perpendicular leaf motion (0-collimator) resulted in small dose changes for PTV-D95 (−13cGy) and GTV-D98 (+18cGy) for the centroid tracking case compared to the initial plan. Modest reductions of OAR doses (e.g. spinal cord D2: −11cGy) were achieved in the idealized tracking case. Conclusion: This study presents an automated “1-click” workflow for computing deliverable MLC tracking doses in RayStation. Adding a non

  2. Cone-beam computed tomography evaluation of the association of cortical plate proximity and apical root resorption after orthodontic treatment.

    Science.gov (United States)

    Nakada, Tomoo; Motoyoshi, Mitsuru; Horinuki, Eri; Shimizu, Noriyoshi

    2016-01-01

    We investigated the effects of proximity of the root apex to the maxillary labial cortical plate, palatal cortical plate, and incisive canal cortical plate on apical root resorption. Cone-beam computed tomography was used to measure the amount of root resorption and root apex movement around maxillary right and left central incisors in 30 adults who underwent four-bicuspid extraction followed by treatment with multibracket appliances. The patients were divided into three groups on the basis of the direction of root apex movement, after which the correlation between the amount of root resorption and root apex movement was determined. Mean apical root resorption was 1.80 ± 0.82 mm (range, 0.18-3.96 mm). The amount of root apex movement was positively correlated with the amount of root resorption on the side of pressure. Root apex proximity to the maxillary labial cortical plate, palatal cortical plate, and incisive canal cortical plate was associated with apical root resorption. Orthodontic treatment plans should carefully consider root proximity to the maxillary cortical plate. (J Oral Sci 58, 231-236, 2016).

  3. A Case Report of Preoperative Application of Cone Beam Computed Tomography in Diagnosis and Treatment of Central Giant Cell Granuloma

    Directory of Open Access Journals (Sweden)

    M. Ebrahimi

    2012-07-01

    Full Text Available Introduction: Central giant cell granuloma(CGCG is a relatively rare and non neoplastic tumor with unclear exact etiology that is reported in children. Cone beam computed tomography (CBCT technique for precise diagnosis and treatment of the jaw lesions is recommended in the recent years. The object of this case-report study is to use CBCT in the diagnosis and treatment of CGCG.Case Report: A 6-year-old boy with a painless swallowing at the right side of the lower face had been arisen 3 months before referring to the pediatric department of Mashhad dental school .The lesion had bony hard consistency and smooth surface. For more accurate examination of the region CBCT radiographs were recommended. According to CBCT radiographic sections, expansion of cortical plates and precise extension of the lesion in buccal-lingual and mesial-distal aspects were distinctly observed.Conclusion: A 12 month follow up after the surgery showed reconstruction and growth of the bone and no sign of recurrence.(Sci J Hamadan Univ Med Sci 2012;19(2:69-74

  4. Internal structure of mandible around mandibular molar using computed tomography. Anatomical consideration of molar anchorage in orthodontic treatment

    International Nuclear Information System (INIS)

    Enomoto, Yutaka; Yamashita, Daisuke; Saito, Katsuhiko; Kasai, Kazutaka

    2008-01-01

    For establishment of fine occlusion, facial profile and oral function in orthodontic treatment, molar anchorage in teeth movement is important manner in extracted cases. The aims of this study were to investigate the relationship between facial morphology and internal structure of mandibular body in molar region by computer tomography, and to discuss about molar anchorage in orthodontic treatment. The data for this study were obtained from 35 modern male Japanese skulls (mean age; 27 year-old, ranged from 18 year-old to 47 year-old). Measurement variables were FMA, SN to mandibular plane angle, gonial angle, alveolar breadth, cortical bone thickness of buccal and lingual sides, and the distance between dental root and cortical bone. As a result, alveolar breadth and the distance between dental root and cortical bone were narrow in long facial type, on the contrary, these variables were wide in short facial type. The result suggested that these variables were considered important factors as molar anchorage in extracted cases. (author)

  5. TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T; Boone, J [University of California Davis School of Medicine, Sacramento, CA (United States); Kent, M; Wisner, E [University of California Davis School of Veterinary Medicine, Davis, CA (United States); Fujita, Y [Tokai University, Isehara (Japan)

    2015-06-15

    Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R{sup 2}=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral-to-dorsal gradient of HU enhancement, providing proof-of-principle for single-energy CT pulmonary perfusion imaging. This ongoing study will enroll more dogs and investigate the physiological significance. This study was supported by a Philips Healthcare/Radiological Society of North America (RSNA) Research Seed Grant (RSD1458)

  6. Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

    Science.gov (United States)

    Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

    2016-10-26

    To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus ( r = 0.79, P optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

  7. Novel high-resolution computed tomography-based radiomic classifier for screen-identified pulmonary nodules in the National Lung Screening Trial.

    Science.gov (United States)

    Peikert, Tobias; Duan, Fenghai; Rajagopalan, Srinivasan; Karwoski, Ronald A; Clay, Ryan; Robb, Richard A; Qin, Ziling; Sicks, JoRean; Bartholmai, Brian J; Maldonado, Fabien

    2018-01-01

    Optimization of the clinical management of screen-detected lung nodules is needed to avoid unnecessary diagnostic interventions. Herein we demonstrate the potential value of a novel radiomics-based approach for the classification of screen-detected indeterminate nodules. Independent quantitative variables assessing various radiologic nodule features such as sphericity, flatness, elongation, spiculation, lobulation and curvature were developed from the NLST dataset using 726 indeterminate nodules (all ≥ 7 mm, benign, n = 318 and malignant, n = 408). Multivariate analysis was performed using least absolute shrinkage and selection operator (LASSO) method for variable selection and regularization in order to enhance the prediction accuracy and interpretability of the multivariate model. The bootstrapping method was then applied for the internal validation and the optimism-corrected AUC was reported for the final model. Eight of the originally considered 57 quantitative radiologic features were selected by LASSO multivariate modeling. These 8 features include variables capturing Location: vertical location (Offset carina centroid z), Size: volume estimate (Minimum enclosing brick), Shape: flatness, Density: texture analysis (Score Indicative of Lesion/Lung Aggression/Abnormality (SILA) texture), and surface characteristics: surface complexity (Maximum shape index and Average shape index), and estimates of surface curvature (Average positive mean curvature and Minimum mean curvature), all with Pscreen-detected nodule characterization appears extremely promising however independent external validation is needed.

  8. Feasibility of differential quantification of 3D temporomandibular kinematics during various oral activities using a cone-beam computed tomography-based 3D fluoroscopic method

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2013-06-01

    Conclusion: A new CBCT-based 3D fluoroscopic method was proposed and shown to be capable of quantitatively differentiating TMJ movement patterns among complicated functional activities. It also enabled a complete description of the rigid-body mandibular motion and descriptions of as many reference points as needed for future clinical applications. It will be helpful for dental practice and for a better understanding of the functions of the TMJ.

  9. Computed tomography-based lung nodule volumetry - do optimized reconstructions of routine protocols achieve similar accuracy, reproducibility and interobserver variability to that of special volumetry protocols?

    International Nuclear Information System (INIS)

    Bolte, H.; Riedel, C.; Knoess, N.; Hoffmann, B.; Heller, M.; Biederer, J.; Freitag, S.

    2007-01-01

    Purpose: The aim of this in vitro and ex vivo CT study was to investigate whether the use of a routine thorax protocol (RTP) with optimized reconstruction parameters can provide comparable accuracy, reproducibility and interobserver variability of volumetric analyses to that of a special volumetry protocol (SVP). Materials and Methods: To assess accuracy, 3 polyurethane (PU) spheres (35 HU; diameters: 4, 6 and 10 mm) were examined with a recommended SVP using a multislice CT (collimation 16 x 0.75 mm, pitch 1.25, 20 mAs, slice thickness 1 mm, increment 0.7 mm, medium kernel) and an optimized RTP (collimation 16 x 1.5 mm, pitch 1.25, 100 mAs, reconstructed slice thickness 2 mm, increment 0.4 mm, sharp kernel). For the assessment of intrascan and interscan reproducibility and interobserver variability, 20 artificial small pulmonary nodules were placed in a dedicated ex vivo chest phantom and examined with identical scan protocols. The artificial lesions consisted of a fat-wax-Lipiodol registered mixture. Phantoms and ex vivo lesions were examined afterwards using commercial volumetry software. To describe accuracy the relative deviations from the true volumes of the PU phantoms were calculated. For intrascan and interscan reproducibility and interobserver variability, the 95 % normal range (95 % NR) of relative deviations between two measurements was calculated. Results: For the SVP the achieved relative deviations for the 4, 6 and 10 mm PU phantoms were - 14.3 %, - 12.7 % and - 6.8 % and were 4.5 %, - 0.6 % and - 2.6 %, respectively, for the optimized RTP. SVP showed a 95 % NR of 0 - 1.5 % for intrascan and a 95 % NR of - 10.8 - 2.9 % for interscan reproducibility. The 95 % NR for interobserver variability was - 4.3 - 3.3 %. The optimized RTP achieved a 95 % NR of - 3.1 - 4.3 % for intrascan reproducibility and a 95 % NR of - 7.0 - 3.5 % for interscan reproducibility. The 95 % NR for interobserver variability was - 0.4 - 6.8 %. (orig.)

  10. TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

    International Nuclear Information System (INIS)

    Yamamoto, T; Boone, J; Kent, M; Wisner, E; Fujita, Y

    2015-01-01

    Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R"2=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral-to-dorsal gradient of HU enhancement, providing proof-of-principle for single-energy CT pulmonary perfusion imaging. This ongoing study will enroll more dogs and investigate the physiological significance. This study was supported by a Philips Healthcare/Radiological Society of North America (RSNA) Research Seed Grant (RSD1458)

  11. Diagnosis of drowning using post-mortem computed tomography based on the volume and density of fluid accumulation in the maxillary and sphenoid sinuses.

    Science.gov (United States)

    Kawasumi, Yusuke; Kawabata, Tomoyoshi; Sugai, Yusuke; Usui, Akihito; Hosokai, Yoshiyuki; Sato, Miho; Saito, Haruo; Ishibashi, Tadashi; Hayashizaki, Yoshie; Funayama, Masato

    2013-10-01

    Recent studies have reported that drowning victims frequently have fluid accumulation in the paranasal sinuses, most notably the maxillary and sphenoid sinuses. However, in our previous study, many non-drowning victims also had fluid accumulation in the sinuses. Therefore, we evaluated the qualitative difference in fluid accumulation between drowning and non-drowning cases in the present study. Thirty-eight drowning and 73 non-drowning cases were investigated retrospectively. The fluid volume and density of each case were calculated using a DICOM workstation. The drowning cases were compared with the non-drowning cases using the Mann-Whitney U-test because the data showed non-normal distribution. The median fluid volume was 1.82 (range 0.02-11.7) ml in the drowning cases and 0.49 (0.03-8.7) ml in the non-drowning cases, and the median fluid density was 22 (-14 to 66) and 39 (-65 to 77) HU, respectively. Both volume and density differed significantly between the drowning and non-drowning cases (p=0.001, p=0.0007). Regarding cut-off levels in the ROC analysis, the points on the ROC curve closest (0, 1) were 1.03ml (sensitivity 68%, specificity 68%, PPV 53%, NPV 81%) and 27.5 HU (61%, 70%, 51%, 77%). The Youden indices were 1.03ml and 37.8 HU (84%, 51%, 47%, 86%). When the cut-off level was set at 1.03ml and 27.5HU, the sensitivity was 42%, specificity 45%, PPV 29% and NPV 60%. When the cut-off level was set at 1.03ml and 37.8HU, sensitivity was 58%, specificity 32%, PPV 31% and NPV 59%. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Root resorption due to orthodontic treatment using self-ligating and conventional brackets : A cone-beam computed tomography study.

    Science.gov (United States)

    Aras, Isil; Unal, Idil; Huniler, Gencer; Aras, Aynur

    2018-05-01

    Purpose of the present study was to compare external root resorption (ERR) volumetrically in maxillary incisors induced by orthodontic treatment using self-ligating brackets (Damon Q, DQ) or conventional brackets (Titanium Orthos, TO) with the help of cone-beam computed tomography (CBCT). A sample of 32 subjects, with Angle Class I malocclusion and anterior crowding of 4-10 mm, was divided randomly into two groups: a DQ group, in which self-ligating DQ brackets with Damon archwires were used; and a TO group, in which conventional TO brackets with large Orthos archwires were applied. The study was conducted using CBCT scans taken before (T1), and near the end (9 months after the initiation of treatment; T2) of the orthodontic treatment. The extent of ERR was determined volumetrically using Mimics software. Changes in root volume were evaluated by repeated-measures analysis of variance as well as by paired and independent t-tests. While significant differences were found between T1 and T2 for root volume in both groups (p  0.05). Maxillary central and lateral incisors showed similar volume loss (p > 0.05). Furthermore, the TO group showed a higher prevalence of palatinal and proximal slanted RR compared with the DQ group (p bracket system over the other only considering root resorption pattern or amount. Higher incidence of slanted RR found in patients treated with the TO system warrants further research to identify possible specific causes.

  13. Acceptability of the use of cellular telephone and computer pictures/video for "pill counts" in buprenorphine maintenance treatment.

    Science.gov (United States)

    Welsh, Christopher

    2016-01-01

    As part of a comprehensive plan to attempt to minimize the diversion of prescribed controlled substances, many professional organization and licensing boards are recommending the use of "pill counts." This study sought to evaluate acceptability of the use of cellular phone and computer pictures/video for "pill counts" by patients in buprenorphine maintenance treatment. Patients prescribed buprenorphine/naloxone were asked a series of questions related to the type(s) of electronic communication to which they had access as well as their willingness to use these for the purpose of performing a "pill/film count." Of the 80 patients, 4 (5 percent) did not have a phone at all. Only 28 (35 percent) had a "smart phone" with some sort of data plan and Internet access. Forty (50 percent) of the patients had a phone with no camera and 10 (12.5 percent) had a phone with a camera but no video capability. All patients said that they would be willing to periodically use the video or camera on their phone or computer to have buprenorphine/naloxone pills or film counted as long as the communication was protected from electronic tampering. With the advent of applications for smart phones that allow for Health Insurance Portability and Accountability Act of 1996-compliant picture/video communication, a number of things can now be done that can enhance patient care as well as reduce the chances of misuse/diversion of prescribed medications. This could be used in settings where a larger proportion of controlled substances are prescribed including medication assisted therapy for opioid use disorders and pain management programs.

  14. A PDE-constrained SQP algorithm for optical tomography based on the frequency-domain equation of radiative transfer

    International Nuclear Information System (INIS)

    Kim, Hyun Keol; Hielscher, Andreas H

    2009-01-01

    It is well acknowledged that transport-theory-based reconstruction algorithm can provide the most accurate reconstruction results especially when small tissue volumes or high absorbing media are considered. However, these codes have a high computational burden and are often only slowly converging. Therefore, methods that accelerate the computation are highly desirable. To this end, we introduce in this work a partial-differential-equation (PDE) constrained approach to optical tomography that makes use of an all-at-once reduced Hessian sequential quadratic programming (rSQP) scheme. The proposed scheme treats the forward and inverse variables independently, which makes it possible to update the radiation intensities and the optical coefficients simultaneously by solving the forward and inverse problems, all at once. We evaluate the performance of the proposed scheme with numerical and experimental data, and find that the rSQP scheme can reduce the computation time by a factor of 10–25, as compared to the commonly employed limited memory BFGS method. At the same time accuracy and robustness even in the presence of noise are not compromised

  15. Brain-computer interface game applications for combined neurofeedback and biofeedback treatment for children on the autism spectrum

    Directory of Open Access Journals (Sweden)

    Elisabeth V C Friedrich

    2014-07-01

    Full Text Available Individuals with Autism Spectrum Disorder (ASD show deficits in social and communicative skills, including imitation, empathy, and shared attention, as well as restricted interests and repetitive patterns of behaviors. Evidence for and against the idea that dysfunctions in the mirror neuron system are involved in imitation and could be one underlying cause for ASD is discussed in this review. Neurofeedback interventions have reduced symptoms in children with ASD by self-regulation of brain rhythms. However, cortical deficiencies are not the only cause of these symptoms. Peripheral physiological activity, such as the heart rate, is closely linked to neurophysiological signals and associated with social engagement. Therefore, a combined approach targeting the interplay between brain, body and behavior could be more effective. Brain-computer interface applications for combined neurofeedback and biofeedback treatment for children with ASD are currently nonexistent. To facilitate their use, we have designed an innovative game that includes social interactions and provides neural- and body-based feedback that corresponds directly to the underlying significance of the trained signals as well as to the behavior that is reinforced.

  16. CARL: a LabVIEW 3 computer program for conducting exposure therapy for the treatment of dental injection fear.

    Science.gov (United States)

    Coldwell, S E; Getz, T; Milgrom, P; Prall, C W; Spadafora, A; Ramsay, D S

    1998-04-01

    This paper describes CARL (Computer Assisted Relaxation Learning), a computerized, exposure-based therapy program for the treatment of dental injection fear. The CARL program operates primarily in two different modes; in vitro, which presents a video-taped exposure hierarchy, and in vivo, which presents scripts for a dentist or hygienist to use while working with a subject. Two additional modes are used to train subjects to use the program and to administer behavioral assessment tests. The program contains five different modules, which function to register a subject, train subjects to use physical and cognitive relaxation techniques, deliver an exposure hierarchy, question subjects about the helpfulness of each of the therapy components, and test for memory effects of anxiolytic medication. Nine subjects have completed the CARL therapy program and 1-yr follow-up as participants in a placebo-controlled clinical trial examining the effects of alprazolam on exposure therapy for dental injection phobia. All nine subjects were able to receive two dental injections, and all reduced their general fear of dental injections. Initial results therefore indicate that the CARL program successfully reduces dental injection fear.

  17. Effects of polytetrafluoroethylene treatment and compression on gas diffusion layer microstructure using high-resolution X-ray computed tomography

    Science.gov (United States)

    Khajeh-Hosseini-Dalasm, Navvab; Sasabe, Takashi; Tokumasu, Takashi; Pasaogullari, Ugur

    2014-11-01

    The microstructure of a TGP-H-120 Toray paper gas diffusion layer (GDL) was investigated using high resolution X-ray computed tomography (CT) technique, with a resolution of 1.8 μm and a field of view (FOV) of ∼1.8 × 1.8 mm. The images obtained from the tomography scans were further post processed, and image thresholding and binarization methodologies are presented. The validity of Otsu's thresholding method was examined. Detailed information on bulk porosity and porosity distribution of the GDL at various Polytetrafluoroethylene (PTFE) treatments and uniform/non-uniform compression pressures was provided. A sample holder was designed to investigate the effects of non-uniform compression pressure, which enabled regulating compression pressure between 0, and 3 MPa at a gas channel/current collector rib configuration. The results show the heterogeneous and anisotropic microstructure of the GDL, non-uniform distribution of PTFE, and significant microstructural change under uniform/non-uniform compression. These findings provide useful inputs for numerical models to include the effects of microstructural changes in the study of transport phenomena within the GDL and to increase the accuracy and predictability of cell performance.

  18. Brain-computer interface game applications for combined neurofeedback and biofeedback treatment for children on the autism spectrum.

    Science.gov (United States)

    Friedrich, Elisabeth V C; Suttie, Neil; Sivanathan, Aparajithan; Lim, Theodore; Louchart, Sandy; Pineda, Jaime A

    2014-01-01

    Individuals with autism spectrum disorder (ASD) show deficits in social and communicative skills, including imitation, empathy, and shared attention, as well as restricted interests and repetitive patterns of behaviors. Evidence for and against the idea that dysfunctions in the mirror neuron system are involved in imitation and could be one underlying cause for ASD is discussed in this review. Neurofeedback interventions have reduced symptoms in children with ASD by self-regulation of brain rhythms. However, cortical deficiencies are not the only cause of these symptoms. Peripheral physiological activity, such as the heart rate and its variability, is closely linked to neurophysiological signals and associated with social engagement. Therefore, a combined approach targeting the interplay between brain, body, and behavior could be more effective. Brain-computer interface applications for combined neurofeedback and biofeedback treatment for children with ASD are currently nonexistent. To facilitate their use, we have designed an innovative game that includes social interactions and provides neural- and body-based feedback that corresponds directly to the underlying significance of the trained signals as well as to the behavior that is reinforced.

  19. Breast-conserving therapy in patients with bilateral breast cancer: Do today's treatment choices burn bridges for tomorrow?

    International Nuclear Information System (INIS)

    Gilroy, Jeffrey S.; Morris, Christopher G.; Mendenhall, Nancy Price

    2005-01-01

    Purpose: To determine how often initial treatment choices limit treatment options for subsequent breast cancer management in patients undergoing breast-conserving therapy (BCT), in particular with treatment of internal mammary nodes. Methods and Materials: Between January 1985 and June 2001, 464 women with pathologic Stage 0, I, and II (T0-2, N0-1) breast cancer underwent BCT at our institution. All 464 patients had computed tomography-based treatment planning. In patients with bilateral breast cancer, the planning computed tomography scans were used to determine the impact initial radiation therapy fields had on treatment options for subsequent contralateral breast cancer. Results: There were 500 breast cancers diagnosed in 464 patients. Thirty-six patients (8%) had bilateral breast cancer with 9 (2%) synchronous and 27 (6%) metachronous primaries. In 80 patients, the ipsilateral internal mammary nodes were explicitly treated. Initial breast cancer treatment choices impacted subsequent treatment decisions for the contralateral breast in only 2 of 464 patients (0.4%) in the study: 2 of 80 patients (2.5%) whose internal mammary nodes were treated, and 2 of 27 patients (7.4%) who developed metachronous bilateral breast cancer. Conclusions: Initial BCT, including internal mammary node irradiation, rarely compromised future contralateral breast-conserving therapy

  20. Quantifying Appropriate PTV Setup Margins: Analysis of Patient Setup Fidelity and Intrafraction Motion Using Post-Treatment Megavoltage Computed Tomography Scans

    International Nuclear Information System (INIS)

    Drabik, Donata M.; MacKenzie, Marc A.; Fallone, Gino B.

    2007-01-01

    Purpose: To present a technique that can be implemented in-house to evaluate the efficacy of immobilization and image-guided setup of patients with different treatment sites on helical tomotherapy. This technique uses an analysis of alignment shifts between kilovoltage computed tomography and post-treatment megavoltage computed tomography images. The determination of the shifts calculated by the helical tomotherapy software for a given site can then be used to define appropriate planning target volume internal margins. Methods and Materials: Twelve patients underwent post-treatment megavoltage computed tomography scans on a helical tomotherapy machine to assess patient setup fidelity and net intrafraction motion. Shifts were studied for the prostate, head and neck, and glioblastoma multiforme. Analysis of these data was performed using automatic and manual registration of the kilovoltage computed tomography and post-megavoltage computed tomography images. Results: The shifts were largest for the prostate, followed by the head and neck, with glioblastoma multiforme having the smallest shifts in general. It appears that it might be more appropriate to use asymmetric planning target volume margins. Each margin value reported is equal to two standard deviations of the average shift in the given direction. Conclusion: This method could be applied using individual patient post-image scanning and combined with adaptive planning to reduce or increase the margins as appropriate

  1. Comparison between anterior segmental osteotomy versus conventional orthodontic treatment in root resorption: a radiographic study using cone-beam computed tomography.

    Science.gov (United States)

    Hwang, Bo-Yeon; Choi, Byung-Joon; Lee, Baek-Soo; Kwon, Yong-Dae; Lee, Jung-Woo; Jung, Junho; Ohe, Joo-Young

    2017-12-01

    Patients who received orthodontic treatment are likely to have apical root shortening. It appears that external apical root resorption results from a combination of patient-related risk factors such as genetic influences, systemic factors, and orthodontic treatment-related factors. Regarding the fact that the anterior segmental osteotomy (ASO) has been known for its possibility of complementing external apical root resorption and of buffering periodontal problems, it has been the preferred treatment. However, the studies on the efficacy of ASO in preserving the root are not sufficient. In this study, we compared the amount of root resorption between the patients who only received orthodontic treatment and the patients who received orthodontic treatment with ASO. This study included 28 patients (the number of incisor = 198) who received orthodontic treatment with or without ASO. We categorize them into groups A and B by the type of orthodontic treatment (group A: conventional orthodontic treatment; group B: orthodontic treatment with ASO). Cone-beam computed tomographic and cephalometric evaluations were retrospectively performed on the radiographs taken for the diagnosis of the treatment before treatment and at the end of active treatment. In group B, root resorption itself and its rate both turned out to have significantly lower than those in group A. Also, the change of incisal angle is significantly smaller in group B than in group A. On the other hand, in group A, the change of incisal angle was positively correlated with the change of AP (anteroposterior) position. In group B, the change of incisal angle was negatively correlated with the duration of the orthodontic treatment. In group B, amount of root resorption (mm) was positively correlated with the duration of the orthodontic treatment. The results show lesser root resorption and shorter treatment duration with ASO than with conventional orthodontic treatment. Therefore, if the indications are accurately

  2. Hepatocellular carcinoma: computed tomography assessment after invasive treatment;Hepatocarcinoma: Evaluacion con tomografia computada luego del tratamiento intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Kozima, Shigeru; Larranaga, Nebil; Wulfson, Gabriela [Servicio de Diagnostico por Imagenes Hospital General de Agudos ' Cosme Argerich' , CABA, Buenos Aires (Argentina); Departamento de Imagenes, CEMIC, Buenos Aires (Argentina); Eisele, Guillermo [Departamento de Imagenes, CEMIC, Buenos Aires (Argentina); Ridruejo, Ezequiel; Mando, Oscar [Seccion de Hepatologia. Departamento de Medicina, CEMIC, Buenos Aires (Argentina); Perazzo, Florencia [Seccion Oncologia. Departamento de Medicina, CEMIC, Buenos Aires (Argentina)

    2008-07-01

    Objective: To show the computed tomography (CT) usefulness after treatment with transcatheter arterial quimioembolization and radiofrequency ablation of hepatocellular carcinoma. Material and methods: In a period between march 2006 to april 2008 a total of 90 patient presenting 148 nodular lesions with diagnosis of hepatocellular carcinoma were controlled with triphasic CT. All the lesions were treated with minimally invasive procedure. For the treatment, the patients were classified in two groups following Milan criteria. The first group, constituted by 75 patients with 109 nodules, was treated with quimioembolization. The second group, of 15 patients with 25 nodules, was treated with radiofrequency ablation. In our population, a subgroup of 10 patients was treated with both methods. Results: Of 90 patients after CT control on a month, 3 months and for each 3 months during 2 years, on 63 cases (70%) was observed homogeneous accumulation of iodized oil, partial defect without enhancement or absence of enhancement on treated lesions. In these patients a new treatment after initial one was not performed. The remaining 27 patients (30%) underwent new treatment because we founded partial defect or absence of iodized oil with enhancement or peripheral enhancement on arterial phase in treated lesions. In this last group, 16 treated patients (17.7%) had new nodular enhancement on the remaining hepatic parenquimal. Conclusion: The CT unenhanced and the arterial phase on a month and for each 3 months, allow monitoring the effectiveness, residual disease and/or relapse of hepatocellular carcinoma after minimally invasive treatment. (authors);Objetivo: Mostrar la utilidad de la tomografia computada trifasica (TCT) luego del tratamiento con quimioembolizacion y ablacion por radiofrecuencia (RF) del hepatocarcinoma (HCC). Material y metodos: En un periodo comprendido entre marzo de 2006 y abril de 2008 se controlaron con TCT 90 pacientes que presentaron 148 lesiones nodulares y

  3. Clinical and cost effectiveness of computer treatment for aphasia post stroke (Big CACTUS): study protocol for a randomised controlled trial.

    Science.gov (United States)

    Palmer, Rebecca; Cooper, Cindy; Enderby, Pam; Brady, Marian; Julious, Steven; Bowen, Audrey; Latimer, Nicholas

    2015-01-27

    Aphasia affects the ability to speak, comprehend spoken language, read and write. One third of stroke survivors experience aphasia. Evidence suggests that aphasia can continue to improve after the first few months with intensive speech and language therapy, which is frequently beyond what resources allow. The development of computer software for language practice provides an opportunity for self-managed therapy. This pragmatic randomised controlled trial will investigate the clinical and cost effectiveness of a computerised approach to long-term aphasia therapy post stroke. A total of 285 adults with aphasia at least four months post stroke will be randomly allocated to either usual care, computerised intervention in addition to usual care or attention and activity control in addition to usual care. Those in the intervention group will receive six months of self-managed word finding practice on their home computer with monthly face-to-face support from a volunteer/assistant. Those in the attention control group will receive puzzle activities, supplemented by monthly telephone calls. Study delivery will be coordinated by 20 speech and language therapy departments across the United Kingdom. Outcome measures will be made at baseline, six, nine and 12 months after randomisation by blinded speech and language therapist assessors. Primary outcomes are the change in number of words (of personal relevance) named correctly at six months and improvement in functional conversation. Primary outcomes will be analysed using a Hochberg testing procedure. Significance will be declared if differences in both word retrieval and functional conversation at six months are significant at the 5% level, or if either comparison is significant at 2.5%. A cost utility analysis will be undertaken from the NHS and personal social service perspective. Differences between costs and quality-adjusted life years in the three groups will be described and the incremental cost effectiveness ratio

  4. Unified treatment of microscopic boundary conditions and efficient algorithms for estimating tangent operators of the homogenized behavior in the computational homogenization method

    Science.gov (United States)

    Nguyen, Van-Dung; Wu, Ling; Noels, Ludovic

    2017-03-01

    This work provides a unified treatment of arbitrary kinds of microscopic boundary conditions usually considered in the multi-scale computational homogenization method for nonlinear multi-physics problems. An efficient procedure is developed to enforce the multi-point linear constraints arising from the microscopic boundary condition either by the direct constraint elimination or by the Lagrange multiplier elimination methods. The macroscopic tangent operators are computed in an efficient way from a multiple right hand sides linear system whose left hand side matrix is the stiffness matrix of the microscopic linearized system at the converged solution. The number of vectors at the right hand side is equal to the number of the macroscopic kinematic variables used to formulate the microscopic boundary condition. As the resolution of the microscopic linearized system often follows a direct factorization procedure, the computation of the macroscopic tangent operators is then performed using this factorized matrix at a reduced computational time.

  5. Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs

    International Nuclear Information System (INIS)

    Walker, Gary V.; Niikura, Naoki; Yang Wei; Rohren, Eric; Valero, Vicente; Woodward, Wendy A.; Alvarez, Ricardo H.; Lucci, Anthony; Ueno, Naoto T.; Buchholz, Thomas A.

    2012-01-01

    Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes

  6. A web-based remote radiation treatment planning system using the remote desktop function of a computer operating system: a preliminary report.

    Science.gov (United States)

    Suzuki, Keishiro; Hirasawa, Yukinori; Yaegashi, Yuji; Miyamoto, Hideki; Shirato, Hiroki

    2009-01-01

    We developed a web-based, remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution. Network security was based on a firewall and a virtual private network (VPN). Client computers were installed at a cancer centre, at a university hospital and at a staff home. We remotely operated the treatment planning computer using the Remote Desktop function built in to the Windows operating system. Except for the initial setup of the VPN router, no special knowledge was needed to operate the remote radiation treatment planning system. There was a time lag that seemed to depend on the volume of data traffic on the Internet, but it did not affect smooth operation. The initial cost and running cost of the system were reasonable.

  7. Effects of a manualized short-term treatment of internet and computer game addiction (STICA: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Jäger Susanne

    2012-04-01

    Full Text Available Abstract Background In the last few years, excessive internet use and computer gaming have increased dramatically. Salience, mood modification, tolerance, withdrawal symptoms, conflict, and relapse have been defined as diagnostic criteria for internet addiction (IA and computer addiction (CA in the scientific community. Despite a growing number of individuals seeking help, there are no specific treatments of established efficacy. Methods/design This clinical trial aims to determine the effect of the disorder-specific manualized short-term treatment of IA/CA (STICA. The cognitive behavioural treatment combines individual and group interventions with a total duration of 4 months. Patients will be randomly assigned to STICA treatment or to a wait list control group. Reliable and valid measures of IA/CA and co-morbid mental symptoms (for example social anxiety, depression will be assessed prior to the beginning, in the middle, at the end, and 6 months after completion of treatment. Discussion A treatment of IA/CA will establish efficacy and is desperately needed. As this is the first trial to determine efficacy of a disorder specific treatment, a wait list control group will be implemented. Pros and cons of the design were discussed. Trial Registration ClinicalTrials (NCT01434589

  8. Effects of a manualized short-term treatment of internet and computer game addiction (STICA): study protocol for a randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background In the last few years, excessive internet use and computer gaming have increased dramatically. Salience, mood modification, tolerance, withdrawal symptoms, conflict, and relapse have been defined as diagnostic criteria for internet addiction (IA) and computer addiction (CA) in the scientific community. Despite a growing number of individuals seeking help, there are no specific treatments of established efficacy. Methods/design This clinical trial aims to determine the effect of the disorder-specific manualized short-term treatment of IA/CA (STICA). The cognitive behavioural treatment combines individual and group interventions with a total duration of 4 months. Patients will be randomly assigned to STICA treatment or to a wait list control group. Reliable and valid measures of IA/CA and co-morbid mental symptoms (for example social anxiety, depression) will be assessed prior to the beginning, in the middle, at the end, and 6 months after completion of treatment. Discussion A treatment of IA/CA will establish efficacy and is desperately needed. As this is the first trial to determine efficacy of a disorder specific treatment, a wait list control group will be implemented. Pros and cons of the design were discussed. Trial Registration ClinicalTrials (NCT01434589) PMID:22540330

  9. Effects of a manualized short-term treatment of internet and computer game addiction (STICA): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Jäger, Susanne; Müller, Kai W; Ruckes, Christian; Wittig, Tobias; Batra, Anil; Musalek, Michael; Mann, Karl; Wölfling, Klaus; Beutel, Manfred E

    2012-04-27

    In the last few years, excessive internet use and computer gaming have increased dramatically. Salience, mood modification, tolerance, withdrawal symptoms, conflict, and relapse have been defined as diagnostic criteria for internet addiction (IA) and computer addiction (CA) in the scientific community. Despite a growing number of individuals seeking help, there are no specific treatments of established efficacy. This clinical trial aims to determine the effect of the disorder-specific manualized short-term treatment of IA/CA (STICA). The cognitive behavioural treatment combines individual and group interventions with a total duration of 4 months. Patients will be randomly assigned to STICA treatment or to a wait list control group. Reliable and valid measures of IA/CA and co-morbid mental symptoms (for example social anxiety, depression) will be assessed prior to the beginning, in the middle, at the end, and 6 months after completion of treatment. A treatment of IA/CA will establish efficacy and is desperately needed. As this is the first trial to determine efficacy of a disorder specific treatment, a wait list control group will be implemented. Pros and cons of the design were discussed. ClinicalTrials (NCT01434589).

  10. An adaptive approach to metal artifact reduction in helical computed tomography for radiation therapy treatment planning: Experimental and clinical studies

    International Nuclear Information System (INIS)

    Yazdia, Mehran; Gingras, Luc; Beaulieu, Luc

    2005-01-01

    Purpose: In this article, an approach to metal artifact reduction is proposed that is practical for clinical use in radiation therapy. It is based on a new interpolation scheme of the projections associated with metal implants in helical computed tomography (CT) scanners. Methods and Materials: A three-step approach was developed consisting of an automatic algorithm for metal implant detection, a correction algorithm for helical projections, and a new, efficient algorithm for projection interpolation. The modified raw projection data are transferred back to the CT scanner device where CT slices are regenerated using the built-in reconstruction operator. The algorithm was tested on a CT calibration phantom in which the density of inserted objects are known and on clinical prostate cases with two hip prostheses. The results are evaluated using the CT number and shape of the objects. Results: The validations on a CT calibration phantom with various inserts of known densities show that the algorithm improved the overall image quality by restoring the shape and the representative CT number of the objects in the image. For the clinical hip replacement cases, a large fraction of the bladder, rectum, and prostate that were not visible on the original CT slices were recovered using the algorithm. Precise contouring of the target volume was thus feasible. Without this enhancement, physicians would have drawn bigger margins to be sure to include the target and, at the same time, could have prescribed a lower dose to keep the same level of normal tissue toxicity. Conclusions: In both phantom experiment and patient studies, the algorithm resulted in significant artifact reduction with increases in the reliability of planning procedure for the case of metallic hip prostheses. This algorithm is now clinically used as a preprocessing before treatment planning for metal artifact reduction

  11. The effect of heart failure and left ventricular assist device treatment on right ventricular mechanics: a computational study.

    Science.gov (United States)

    Park, Jun I K; Heikhmakhtiar, Aulia Khamas; Kim, Chang Hyun; Kim, Yoo Seok; Choi, Seong Wook; Song, Kwang Soup; Lim, Ki Moo

    2018-05-22

    Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model. In this study, we combined a three-dimensional finite element electromechanical model of ventricles, which is based on human ventricular morphology captured by magnetic resonance imaging (MRI) with a lumped model of the circulatory system and continuous flow LVAD function in order to construct an integrated model of an LVAD implanted-cardiovascular system. To induce systolic dysfunction, the magnitude of the calcium transient function under HF condition was reduced to 70% of the normal value, and the time constant was reduced by 30% of the normal value. Under the HF condition, the left ventricular end systolic pressure decreased, the left ventricular end diastolic pressure increased, and the pressure in the right atrium (RA), RV, and pulmonary artery (PA) increased compared with the normal condition. The LVAD therapy decreased the end-systolic pressure of the LV by 41%, RA by 29%, RV by 53%, and PA by 71%, but increased the right ventricular ejection fraction by 52% and cardiac output by 40%, while the stroke work was reduced by 67% compared with the HF condition without LVAD. The end-systolic ventricular tension and strain decreased with the LVAD treatment. LVAD enhances CO and mechanical unloading of the LV as well as those of the RV and prevents pulmonary hypertension which can be induced by HF.

  12. Development of a computational program for treatment of texture data by the X-ray diffraction technique

    International Nuclear Information System (INIS)

    Galego, Eguiberto

    2004-01-01

    In this work it has been developed a computational program for treatment of texture data by the X-ray diffraction technique using pole figures. It has been applied the resolution method by spherical harmonical series expansion for cubic and hexagonal microscopic symmetry and orthorhombic macroscopic symmetry. For yielding the microscopic symmetries it has been necessary the implementation of algorithmic for calculation the spherical harmonic of specific surface. The generation of Legendre Polynomial, based on the experimental data in relation to a and β step angles, is execution in real time. In the introduction of data, the graphical representation of pole figure is drawn in stereo graphic projection, being possible to the analyst three dimensional (3D) visualization. An internal routine verify validity of the Miller indexes, being possible to analyst the correction. The program exhibit the possible corrections applied to experimental data: defocusing, background and orientation of lamination direction (β angle). The correction of the defocusing and background is the executed automatically based on the optic used in the X-ray equipment (Schulz geometric). It has been implemented a routine of graphic manipulation of the contour iso lines for generation of the orientation distribution function (ODF), with easy manipulation of the number of lines and colors. In the ODF graphic, with the action of the mouse cursor on any section, it is visualized the values of Euler angles (φ 1 , Φ, φ 2 ) and of the respective f(g) intensity. Concomitantly, there is 3D graphic visualization of the crystal position in relation to the rolling direction. There is the possibility of graphic visualization in 3D of any section of the ODF. It is also possible the graphic visualization of the texture fiber. This program was named Texture Analysis Program (TAP). (author)

  13. Root resorption diagnosed with cone beam computed tomography after 6 months and at the end of orthodontic treatment with fixed appliances.

    Science.gov (United States)

    Makedonas, Dimitrios; Lund, Henrik; Hansen, Ken

    2013-05-01

    To investigate the prevalence of orthodontically induced root resorption after treatment and the correlation with resorption found after 6 months of treatment. One hundred fifty-six patients (11-18 years) treated with fixed appliances and extraction of four premolars were examined with cone beam computed tomography before treatment, after 6 months of treatment (n  =  97), and at the end of active treatment. The Malmgren Index was used to describe the degree of root resorption. Severe root resorption (>2 mm, score 3) was found in 25.6% of the patients at the end of treatment. Extreme root resorption was found in one patient. Root resorption was seen more frequently in the maxillary incisor region. There was no correlation between the severity of root resorption after 6 months and the amount observed at the end of treatment. Furthermore, no correlation was seen between treatment duration and the severity of root resorption. Clinically significant resorption was diagnosed in 25.6% of the patients, but no correlations, either with the resorption seen after 6 months or with the length of treatment, were found. Radiographic examination after 3 to 6 months of orthodontic treatment is too early and will not reduce the number of patients who will have teeth with severe root resorption.

  14. A new approach to global seismic tomography based on regularization by sparsity in a novel 3D spherical wavelet basis

    Science.gov (United States)

    Loris, Ignace; Simons, Frederik J.; Daubechies, Ingrid; Nolet, Guust; Fornasier, Massimo; Vetter, Philip; Judd, Stephen; Voronin, Sergey; Vonesch, Cédric; Charléty, Jean

    2010-05-01

    Global seismic wavespeed models are routinely parameterized in terms of spherical harmonics, networks of tetrahedral nodes, rectangular voxels, or spherical splines. Up to now, Earth model parametrizations by wavelets on the three-dimensional ball remain uncommon. Here we propose such a procedure with the following three goals in mind: (1) The multiresolution character of a wavelet basis allows for the models to be represented with an effective spatial resolution that varies as a function of position within the Earth. (2) This property can be used to great advantage in the regularization of seismic inversion schemes by seeking the most sparse solution vector, in wavelet space, through iterative minimization of a combination of the ℓ2 (to fit the data) and ℓ1 norms (to promote sparsity in wavelet space). (3) With the continuing increase in high-quality seismic data, our focus is also on numerical efficiency and the ability to use parallel computing in reconstructing the model. In this presentation we propose a new wavelet basis to take advantage of these three properties. To form the numerical grid we begin with a surface tesselation known as the 'cubed sphere', a construction popular in fluid dynamics and computational seismology, coupled with an semi-regular radial subdivison that honors the major seismic discontinuities between the core-mantle boundary and the surface. This mapping first divides the volume of the mantle into six portions. In each 'chunk' two angular and one radial variable are used for parametrization. In the new variables standard 'cartesian' algorithms can more easily be used to perform the wavelet transform (or other common transforms). Edges between chunks are handled by special boundary filters. We highlight the benefits of this construction and use it to analyze the information present in several published seismic compressional-wavespeed models of the mantle, paying special attention to the statistics of wavelet and scaling coefficients

  15. Iterative image reconstruction for positron emission tomography based on a detector response function estimated from point source measurements

    International Nuclear Information System (INIS)

    Tohme, Michel S; Qi Jinyi

    2009-01-01

    The accuracy of the system model in an iterative reconstruction algorithm greatly affects the quality of reconstructed positron emission tomography (PET) images. For efficient computation in reconstruction, the system model in PET can be factored into a product of a geometric projection matrix and sinogram blurring matrix, where the former is often computed based on analytical calculation, and the latter is estimated using Monte Carlo simulations. Direct measurement of a sinogram blurring matrix is difficult in practice because of the requirement of a collimated source. In this work, we propose a method to estimate the 2D blurring kernels from uncollimated point source measurements. Since the resulting sinogram blurring matrix stems from actual measurements, it can take into account the physical effects in the photon detection process that are difficult or impossible to model in a Monte Carlo (MC) simulation, and hence provide a more accurate system model. Another advantage of the proposed method over MC simulation is that it can easily be applied to data that have undergone a transformation to reduce the data size (e.g., Fourier rebinning). Point source measurements were acquired with high count statistics in a relatively fine grid inside the microPET II scanner using a high-precision 2D motion stage. A monotonically convergent iterative algorithm has been derived to estimate the detector blurring matrix from the point source measurements. The algorithm takes advantage of the rotational symmetry of the PET scanner and explicitly models the detector block structure. The resulting sinogram blurring matrix is incorporated into a maximum a posteriori (MAP) image reconstruction algorithm. The proposed method has been validated using a 3 x 3 line phantom, an ultra-micro resolution phantom and a 22 Na point source superimposed on a warm background. The results of the proposed method show improvements in both resolution and contrast ratio when compared with the MAP

  16. Study protocol: a randomized controlled trial of a computer-based depression and substance abuse intervention for people attending residential substance abuse treatment

    Directory of Open Access Journals (Sweden)

    Kelly Peter J

    2012-02-01

    Full Text Available Abstract Background A large proportion of people attending residential alcohol and other substance abuse treatment have a co-occurring mental illness. Empirical evidence suggests that it is important to treat both the substance abuse problem and co-occurring mental illness concurrently and in an integrated fashion. However, the majority of residential alcohol and other substance abuse services do not address mental illness in a systematic way. It is likely that computer delivered interventions could improve the ability of substance abuse services to address co-occurring mental illness. This protocol describes a study in which we will assess the effectiveness of adding a computer delivered depression and substance abuse intervention for people who are attending residential alcohol and other substance abuse treatment. Methods/Design Participants will be recruited from residential rehabilitation programs operated by the Australian Salvation Army. All participants who satisfy the diagnostic criteria for an alcohol or other substance dependence disorder will be asked to participate in the study. After completion of a baseline assessment, participants will be randomly assigned to either a computer delivered substance abuse and depression intervention (treatment condition or to a computer-delivered typing tutorial (active control condition. All participants will continue to complete The Salvation Army residential program, a predominantly 12-step based treatment facility. Randomisation will be stratified by gender (Male, Female, length of time the participant has been in the program at the commencement of the study (4 weeks or less, 4 weeks or more, and use of anti-depressant medication (currently prescribed medication, not prescribed medication. Participants in both conditions will complete computer sessions twice per week, over a five-week period. Research staff blind to treatment allocation will complete the assessments at baseline, and then 3, 6, 9

  17. A novel post-processing scheme for two-dimensional electrical impedance tomography based on artificial neural networks.

    Directory of Open Access Journals (Sweden)

    Sébastien Martin

    Full Text Available Electrical Impedance Tomography (EIT is a powerful non-invasive technique for imaging applications. The goal is to estimate the electrical properties of living tissues by measuring the potential at the boundary of the domain. Being safe with respect to patient health, non-invasive, and having no known hazards, EIT is an attractive and promising technology. However, it suffers from a particular technical difficulty, which consists of solving a nonlinear inverse problem in real time. Several nonlinear approaches have been proposed as a replacement for the linear solver, but in practice very few are capable of stable, high-quality, and real-time EIT imaging because of their very low robustness to errors and inaccurate modeling, or because they require considerable computational effort.In this paper, a post-processing technique based on an artificial neural network (ANN is proposed to obtain a nonlinear solution to the inverse problem, starting from a linear solution. While common reconstruction methods based on ANNs estimate the solution directly from the measured data, the method proposed here enhances the solution obtained from a linear solver.Applying a linear reconstruction algorithm before applying an ANN reduces the effects of noise and modeling errors. Hence, this approach significantly reduces the error associated with solving 2D inverse problems using machine-learning-based algorithms.This work presents radical enhancements in the stability of nonlinear methods for biomedical EIT applications.

  18. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager

    2015-01-01

    Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years...... was considered to be a ubiquitous phenomenon. However, the understanding of differences in the EPR-effect between tumor types, heterogeneities within each patient group, and dependency on tumor development stage in humans is sparse. It is therefore important to enhance our understanding of the EPR......-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide...

  19. Cost Analyses after a single intervention using a computer application (DIAGETHER in the treatment of diabetic patients admitted to a third level hospital

    Directory of Open Access Journals (Sweden)

    César Carballo Cardona

    2018-01-01

    Full Text Available Goals: To quantify the savings that could be made by the hospital implementation of a computer application (DIAGETHER®, which advises the treatment of hyperglycemia of the diabetic patient in the emergency department when this patient is admitted to a third level hospital. Methods: A multicenter interventional study was designed, including patients in two arms, one in the conventional treatment prescribed by the physician and the other applied the treatment indicated by the computer application DIAGETHER®. The days of hospitalization were collected in the two arms of intervention. Results: A total of 183 patients were included, 86 received treatment with the computer application, and 97 received conventional treatment. The mean blood glucose level on the first day of admission in the GLIKAL group was 178.56 (59.53, compared to 212.93 (62.23 in the conventional group (p <0.001 and on the second day 173.86 (58.86 versus 196.37 (66.60 (p = 0.017. There was no difference in the frequency of hypoglycemia reported in each group (p = 0.555. A reduction in mean stay was observed in patients treated with DIAGETHER. The days of admission were 7 (2-39 days for the GLIKAL group and 10 (2-53 days for the PCH group (p <0.001. Conclusions: The annual savings that could be generated with the use of the computer tool (DIAGETHER®, with the volume of diabetic patients admitted to the hospital, could decrease hospitalization days by 26,147 (14,134 patients for 1.85 days of stay reduction, this would generate a saving of 8,811,842 million euros per year (cost of stay / day of the diabetic patient, for the savings days generated.

  20. Early Assessment of Treatment Responses During Radiation Therapy for Lung Cancer Using Quantitative Analysis of Daily Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Jijo; Yang, Cungeng [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Wu, Hui [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); The Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou (China); Tai, An [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Dalah, Entesar [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Department of Medical Diagnostic Imaging, College of Health Science, University of Sharjah (United Arab Emirates); Zheng, Cheng [Biostatistics, Joseph. J. Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (United States); Johnstone, Candice [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Kong, Feng-Ming [Department of Radiation Oncology, Indiana University, Indianapolis, Indiana (United States); Gore, Elizabeth [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2017-06-01

    Purpose: To investigate early tumor and normal tissue responses during the course of radiation therapy (RT) for lung cancer using quantitative analysis of daily computed tomography (CT) scans. Methods and Materials: Daily diagnostic-quality CT scans acquired using CT-on-rails during CT-guided RT for 20 lung cancer patients were quantitatively analyzed. On each daily CT set, the contours of the gross tumor volume (GTV) and lungs were generated and the radiation dose delivered was reconstructed. The changes in CT image intensity (Hounsfield unit [HU]) features in the GTV and the multiple normal lung tissue shells around the GTV were extracted from the daily CT scans. The associations between the changes in the mean HUs, GTV, accumulated dose during RT delivery, and patient survival rate were analyzed. Results: During the RT course, radiation can induce substantial changes in the HU histogram features on the daily CT scans, with reductions in the GTV mean HUs (dH) observed in the range of 11 to 48 HU (median 30). The dH is statistically related to the accumulated GTV dose (R{sup 2} > 0.99) and correlates weakly with the change in GTV (R{sup 2} = 0.3481). Statistically significant increases in patient survival rates (P=.038) were observed for patients with a higher dH in the GTV. In the normal lung, the 4 regions proximal to the GTV showed statistically significant (P<.001) HU reductions from the first to last fraction. Conclusion: Quantitative analysis of the daily CT scans indicated that the mean HUs in lung tumor and surrounding normal tissue were reduced during RT delivery. This reduction was observed in the early phase of the treatment, is patient specific, and correlated with the delivered dose. A larger HU reduction in the GTV correlated significantly with greater patient survival. The changes in daily CT features, such as the mean HU, can be used for early assessment of the radiation response during RT delivery for lung cancer.

  1. Computed tomography-guided percutaneous ozone injection of the Gasserian ganglion for the treatment of trigeminal neuralgia

    Directory of Open Access Journals (Sweden)

    An JX

    2018-01-01

    Full Text Available Jian-Xiong An,1,2 Hui Liu,1 Ruo-Wen Chen,1,2 Yong Wang,1 Wen-Xing Zhao,1 Derek Eastwood,3 John P Williams4 1Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University & Beijing Institute of Translational Medicine, Chinese Academy of Sciences, 2Department of Anesthesiology, Weifang Medical University, Beijing, People’s Republic of China; 3Department of Pain Services, Wirral University Teaching Hospital, Wirral, Merseyside, UK; 4Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Objective: The aim of this study was to evaluate the therapeutic effect of computed tomography (CT-guided percutaneous ozone injection for refractory trigeminal neuralgia. Design: A retrospective evaluation was performed in the study. Setting: The study was conducted at a university hospital pain center. Patients and methods: A total of 29 patients with a clinical diagnosis of refractory trigeminal neuralgia were enrolled. All patients were treated with a percutaneous ozone injection and one patient was excluded. There were 21 patients with classical trigeminal neuralgia (group A and seven patients with painful trigeminal neuropathy caused by post-herpetic neuralgia (group B. The percutaneous injection was an oxygen–ozone mixture at an ozone concentration of 30 mg/­mL into the Gasserian ganglion performed under CT guidance. The number of ­procedures performed varied from one to as many as 16. Outcomes were evaluated using visual analog scale (VAS pain scores. Results: The combined VAS scores were 7.11 ± 1.23 pretreatment, 2.86 ± 1.69 posttreatment (P < 0.05 and 3.25 ± 2.01 after 6-month follow-up (P < 0.05. In group A, the VAS scores were 7.10 ± 1.04 pretreatment and 2.90 ± 1.84 posttreatment (P < 0.05. In group B, the VAS scores were 7.14 ± 1.77 pretreatment and 2.71 ± 1.25 posttreatment (P < 0.05. After 6-months follow-up, the VAS score was 3.38

  2. Computer-based monitoring and evaluation of epilepsy-related health variables and their impact on treatment decision.

    Science.gov (United States)

    Bergmann, Melanie; Prieschl, Manuela; Walser, Gerald; Luef, Gerhard; Rumpold, Gerhard; Unterberger, Iris

    2018-04-30

    This study aimed to determine the effectiveness of electronic patient-reported outcomes (ePROs) with focus on epilepsy-specific quality of life, psychiatric and psychosocial burden, drug side effects, and patient satisfaction via the Computer-based Health Evaluation System (CHES) and to evaluate their impact on treatment regimen. Forty consecutive patients with drug-resistant focal epilepsy undergoing prolonged video-electroencephalography (EEG) monitoring at the Department of Neurology, Innsbruck Medical University were included and randomized to an intervention group (questionnaire results accessible to the physicians) and a control group (questionnaire results inaccessible to the physicians). Patients had to complete questionnaires on the day of admission (T0) and the day of discharge (T1). Overall, twenty-five patients (25/40, 62.5%) showed abnormal assessment results, twelve of them exclusively due to pathological scores on the Liverpool Adverse Events Profile (LAEP). Mean LAEP score was within the pathological range of 48.8 points (48.8 ± 7.2). The psychosocial burden with respect to the Performance, Socio-Demographic Aspects, Subjective Evaluation (PESOS) scale "fear" (48.7 ± 21.4) was also moderately affected. Moreover, mean anxiety (9.1 ± 4.4) and depression (7.6 ± 4.5) scores were both slightly abnormal. Quality of life (as measured using the Quality of Life Inventory in Epilepsy (QOLIE-31)) was moderately impaired (seizure worry: 46.5 ± 21.3, overall quality of life: 52.6 ± 18.6, well-being: 54.1 ± 16.3, energy-fatigue: 39.4 ± 14.7, cognitive functioning: 41.4 ± 19.5, medication effects: 46.2 ± 23.4, social functioning: 51.1 ± 20.8, and total score: 47.2 ± 12.3). Careful medical history-taking and patient-physician consultations alone failed to detect needs for psychological/psychiatric help in three out of 7 patients in the control group (42.8%). Changes over time in Hospital Anxiety and

  3. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients.

    Science.gov (United States)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine; Bertelsen, Anders; Hope, Andrew; Moseley, Douglas; Brink, Carsten

    2015-10-01

    This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT markers to predict lung density changes induced by radiotherapy was investigated. Age and CBCT markers extracted at 10th, 20th, and 30th treatment fraction significantly predicted lung density changes in a multivariable analysis, and a set of response models based on these parameters were established. The correlation coefficient for the models was 0.35, 0.35, and 0.39, when based on the markers obtained at the 10th, 20th, and 30th fraction, respectively. The study indicates that younger patients without lung tissue reactions early into their treatment course may have minimal radiation induced lung density increase at follow-up. Further investigations are needed to examine the ability of the models to identify patients with low risk of symptomatic toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Long ranging swept-source optical coherence tomography-based angiography outperforms its spectral-domain counterpart in imaging human skin microcirculations

    Science.gov (United States)

    Xu, Jingjiang; Song, Shaozhen; Men, Shaojie; Wang, Ruikang K.

    2017-11-01

    There is an increasing demand for imaging tools in clinical dermatology that can perform in vivo wide-field morphological and functional examination from surface to deep tissue regions at various skin sites of the human body. The conventional spectral-domain optical coherence tomography-based angiography (SD-OCTA) system is difficult to meet these requirements due to its fundamental limitations of the sensitivity roll-off, imaging range as well as imaging speed. To mitigate these issues, we demonstrate a swept-source OCTA (SS-OCTA) system by employing a swept source based on a vertical cavity surface-emitting laser. A series of comparisons between SS-OCTA and SD-OCTA are conducted. Benefiting from the high system sensitivity, long imaging range, and superior roll-off performance, the SS-OCTA system is demonstrated with better performance in imaging human skin than the SD-OCTA system. We show that the SS-OCTA permits remarkable deep visualization of both structure and vasculature (up to ˜2 mm penetration) with wide field of view capability (up to 18×18 mm2), enabling a more comprehensive assessment of the morphological features as well as functional blood vessel networks from the superficial epidermal to deep dermal layers. It is expected that the advantages of the SS-OCTA system will provide a ground for clinical translation, benefiting the existing dermatological practice.

  5. [Patient's Autonomy and Information in Psycho-Oncology: Computer Based Distress Screening for an Interactive Treatment Planning (ePOS-react)].

    Science.gov (United States)

    Schäffeler, Norbert; Sedelmaier, Jana; Möhrer, Hannah; Ziser, Katrin; Ringwald, Johanna; Wickert, Martin; Brucker, Sara; Junne, Florian; Zipfel, Stephan; Teufel, Martin

    2017-07-01

    To identify distressed patients in oncology using screening questionnaires is quite challenging in clinical routine. Up to now there is no evidence based recommendation which instrument is most suitable and how to put a screening to practice. Using computer based screening tools offers the possibility to automatically analyse patient's data, inform psycho-oncological and medical staff about the results, and use reactive questionnaires. Studies on how to empower patients in decision making in psycho-oncology are rare.Methods Women with breast and gynaecological cancer have been consecutively included in this study (n=103) at time of inpatient surgical treatment in a gynaecological clinic. They answered the computer based screening questionnaire (ePOS-react) for routine distress screening at time of admission. At the end of the tool an individual recommendation concerning psycho-oncological treatment is given ( i) psycho-oncological counselling, ii) brief psycho-oncological contact, iii) no treatment suggestion). The informed patients could choose autonomously either the recommended treatment or an individually more favoured alternative possibility. Additionally, a clinical interview (approx. 30 min) based on the "Psychoonkologische Basisdiagnostik (PO-Bado)" has been carried out for a third-party assessment of patients' need for treatment.Results 68.9% followed the treatment recommendation. 22.3% asked for a more "intense" (e. g. counselling instead of recommended brief contact) and 8,7% for a "less intense" intervention than recommended. The accordance of third-party assessment (clinical interview "PO-Bado") and treatment recommendation is about 72.8%. The accordance of third-party assessment and patient's choice (ePOS-react) is about 58.3%. The latter is smaller because 29.1% asked for a brief psycho-oncological contact for whom from the third-party assessment's perspective no indication for treatment has been existent.Discussion A direct response of the

  6. Contribution of cone beam computed tomography to the detection of apical root resorption after orthodontic treatment in root-filled and vital teeth.

    Science.gov (United States)

    Castro, Iury; Valladares-Neto, José; Estrela, Carlos

    2015-09-01

    To investigate whether root-filled teeth are similar to vital pulp teeth in terms of apical root resorption (ARR) after orthodontic treatment. An original sample of cone beam computed tomography (CBCT) images of 1256 roots from 30 orthodontic patients were analyzed. The inclusion criteria demanded root-filled teeth and their contralateral vital teeth, while teeth with history of trauma had to be excluded to comply with exclusion criteria. CBCT images of root-filled teeth were compared before and after orthodontic treatment in a split-mouth design study. Tooth measurements were made with multiplanar reconstruction using axial-guided navigation. The statistical difference between the treatment effects was compared using the paired t-test. Twenty posterior root-filled teeth and their contralaterals with vital pulp were selected before orthodontic treatment from six adolescents (two boys and four girls; mean [SD] age 12.8 [1.8] years). No differences were detected between filled and vital root lengths before treatment (P  =  .4364). The mean differences in root length between preorthodontic and postorthodontic treatment in filled- and vital roots were -0.30 mm and -0.16 mm, respectively, without any statistical difference (P  =  .4197) between them. There appears to be no increase in ARR after orthodontic treatment in root-filled teeth with no earlier ARR.

  7. Effects on mortality, treatment, and time management as a result of routine use of total body computed tomography in blunt high-energy trauma patients.

    Science.gov (United States)

    van Vugt, Raoul; Kool, Digna R; Deunk, Jaap; Edwards, Michael J R

    2012-03-01

    Currently, total body computed tomography (TBCT) is rapidly implemented in the evaluation of trauma patients. With this review, we aim to evaluate the clinical implications-mortality, change in treatment, and time management-of the routine use of TBCT in adult blunt high-energy trauma patients compared with a conservative approach with the use of conventional radiography, ultrasound, and selective computed tomography. A literature search for original studies on TBCT in blunt high-energy trauma patients was performed. Two independent observers included studies concerning mortality, change of treatment, and/or time management as outcome measures. For each article, relevant data were extracted and analyzed. In addition, the quality according to the Oxford levels of evidence was assessed. From 183 articles initially identified, the observers included nine original studies in consensus. One of three studies described a significant difference in mortality; four described a change of treatment in 2% to 27% of patients because of the use of TBCT. Five studies found a gain in time with the use of immediate routine TBCT. Eight studies scored a level of evidence of 2b and one of 3b. Current literature has predominantly suboptimal design to prove terminally that the routine use of TBCT results in improved survival of blunt high-energy trauma patients. TBCT can give a change of treatment and improves time intervals in the emergency department as compared with its selective use.

  8. Using a three-dimensional computer assisted stone volume estimates to evaluate extracorporeal shockwave lithotripsy treatment of kidney stones

    DEFF Research Database (Denmark)

    Bigum, Lene Hyldgaard; Ulriksen, Peter Sommer; Omar, Omar Salah

    2016-01-01

    Hospital between April 2013 and January 2014 and follow-up was possible in 77 (95 %) patients. NCCT was used before and after treatment. Treatment response was expressed as a reduction of the stone volume. Stone characteristics as the stone volumes, HU, SSD and localization were measured by radiologist...

  9. Computational physics

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-01-15

    Computers have for many years played a vital role in the acquisition and treatment of experimental data, but they have more recently taken up a much more extended role in physics research. The numerical and algebraic calculations now performed on modern computers make it possible to explore consequences of basic theories in a way which goes beyond the limits of both analytic insight and experimental investigation. This was brought out clearly at the Conference on Perspectives in Computational Physics, held at the International Centre for Theoretical Physics, Trieste, Italy, from 29-31 October.

  10. Computational physics

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Computers have for many years played a vital role in the acquisition and treatment of experimental data, but they have more recently taken up a much more extended role in physics research. The numerical and algebraic calculations now performed on modern computers make it possible to explore consequences of basic theories in a way which goes beyond the limits of both analytic insight and experimental investigation. This was brought out clearly at the Conference on Perspectives in Computational Physics, held at the International Centre for Theoretical Physics, Trieste, Italy, from 29-31 October

  11. The AUSGeoid98 geoid model of Australia: data treatment, computations and comparisons with GPS-levelling data

    DEFF Research Database (Denmark)

    Featherstone, W.E.; Kirby, J.F.; Kearsley, A.H.W.

    2001-01-01

    The AUSGeoid98 gravimetric geoid model of Australia has been computed using data from the EGM96 global geopotential model, the 1996 release of the Australian gravity database, a nationwide digital elevation model, and satellite altimeter-derived marine gravity anomalies. The geoid heights are on ...

  12. Virtual reality exposure treatment of agoraphobia: a comparison of computer automatic virtual environment and head-mounted display

    NARCIS (Netherlands)

    Meyerbröker, K.; Morina, N.; Kerkhof, G.; Emmelkamp, P.M.G.; Wiederhold, B.K.; Bouchard, S.; Riva, G.

    2011-01-01

    In this study the effects of virtual reality exposure therapy (VRET) were investigated in patients with panic disorder and agoraphobia. The level of presence in VRET was compared between using either a head-mounted display (HMD) or a computer automatic virtual environment (CAVE). Results indicate

  13. Computational identification of potential multitarget treatments for ameliorating the adverse effects of amyloid-β on synaptic plasticity.

    Science.gov (United States)

    Anastasio, Thomas J

    2014-01-01

    The leading hypothesis on Alzheimer Disease (AD) is that it is caused by buildup of the peptide amyloid-β (Aβ), which initially causes dysregulation of synaptic plasticity and eventually causes destruction of synapses and neurons. Pharmacological efforts to limit Aβ buildup have proven ineffective, and this raises the twin challenges of understanding the adverse effects of Aβ on synapses and of suggesting pharmacological means to prevent them. The purpose of this paper is to initiate a computational approach to understanding the dysregulation by Aβ of synaptic plasticity and to offer suggestions whereby combinations of various chemical compounds could be arrayed against it. This data-driven approach confronts the complexity of synaptic plasticity by representing findings from the literature in a course-grained manner, and focuses on understanding the aggregate behavior of many molecular interactions. The same set of interactions is modeled by two different computer programs, each written using a different programming modality: one imperative, the other declarative. Both programs compute the same results over an extensive test battery, providing an essential crosscheck. Then the imperative program is used for the computationally intensive purpose of determining the effects on the model of every combination of ten different compounds, while the declarative program is used to analyze model behavior using temporal logic. Together these two model implementations offer new insights into the mechanisms by which Aβ dysregulates synaptic plasticity and suggest many drug combinations that potentially may reduce or prevent it.

  14. Computational identification of potential multitarget treatments for ameliorating the adverse effects of amyloid-beta on synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Thomas J. Anastasio

    2014-05-01

    Full Text Available The leading hypothesis on Alzheimer Disease (AD is that it is caused by buildup of the peptide amyloid-beta (Abeta, which initially causes dysregulation of synaptic plasticity and eventually causes destruction of synapses and neurons. Pharmacological efforts to limit Abeta buildup have proven ineffective, and this raises the twin challenges of understanding the adverse effects of Abeta on synapses and of suggesting pharmacological means to prevent it. The purpose of this paper is to initiate a computational approach to understanding the dysregulation by Abeta of synaptic plasticity and to offer suggestions whereby combinations of various chemical compounds could be arrayed against it. This data-driven approach confronts the complexity of synaptic plasticity by representing findings from the literature in a course-grained manner, and focuses on understanding the aggregate behavior of many molecular interactions. The same set of interactions is modeled by two different computer programs, each written using a different programming modality: one imperative, the other declarative. Both programs compute the same results over an extensive test battery, providing an essential crosscheck. Then the imperative program is used for the computationally intensive purpose of determining the effects on the model of every combination of ten different compounds, while the declarative program is used to analyze model behavior using temporal logic. Together these two model implementations offer new insights into the mechanisms by which Abeta dysregulates synaptic plasticity and suggest many drug combinations that potentially may reduce or prevent it.

  15. Linking computer-aided design (CAD) to Geant4-based Monte Carlo simulations for precise implementation of complex treatment head geometries

    International Nuclear Information System (INIS)

    Constantin, Magdalena; Constantin, Dragos E; Keall, Paul J; Narula, Anisha; Svatos, Michelle; Perl, Joseph

    2010-01-01

    Most of the treatment head components of medical linear accelerators used in radiation therapy have complex geometrical shapes. They are typically designed using computer-aided design (CAD) applications. In Monte Carlo simulations of radiotherapy beam transport through the treatment head components, the relevant beam-generating and beam-modifying devices are inserted in the simulation toolkit using geometrical approximations of these components. Depending on their complexity, such approximations may introduce errors that can be propagated throughout the simulation. This drawback can be minimized by exporting a more precise geometry of the linac components from CAD and importing it into the Monte Carlo simulation environment. We present a technique that links three-dimensional CAD drawings of the treatment head components to Geant4 Monte Carlo simulations of dose deposition. (note)

  16. Endodontic treatment of a maxillary lateral incisor with a perforating internal resorption by using cone beam computed tomography as a diagnostic aid: a case report.

    Science.gov (United States)

    Takita, Toshiya; Tsurumachi, Tamotsu; Ogiso, Bunnai

    2011-10-01

    This case report presents the endodontic treatment of a maxillary right lateral incisor with a perforating internal resorption in a 50-year-old woman. Radiographically, internal resorption appears as a fairly uniform, radiolucent enlargement of the pulp canal and distortion of the original root canal outline. The use of cone beam computed tomography can help the clinician in making a confirmatory diagnosis and determining the treatment plan before undertaking the actual treatment. After cleaning the root canal space and the resorptive defect by mechanic instrumentation, irrigation, and interim calcium hydroxide dressing, the apical third canal was filled with a gutta-percha point by lateral condensation. The resorptive defect was filled with mineral trioxide aggregate. Follow-up radiographs at 3 years showed adequate repair of the resorption, and the tooth remained asymptomatic.

  17. Computed tomography of cryogenic cells

    International Nuclear Information System (INIS)

    Schneider, Gerd; Anderson, E.; Vogt, S.; Knochel, C.; Weiss, D.; LeGros, M.; Larabell, C.

    2001-01-01

    Due to the short wavelengths of X-rays and low numerical aperture of the Fresnel zone plates used as X-ray objectives, the depth of field is several microns. Within the focal depth, imaging a thick specimen is to a good approximation equivalent to projecting the specimen absorption. Therefore, computed tomography based on a tilt series of X-ray microscopic images can be used to reconstruct the local linear absorption coefficient and image the three-dimensional specimen structure. To preserve the structural integrity of biological objects during image acquisition, microscopy is performed at cryogenic temperatures. Tomography based on X-ray microscopic images was applied to study the distribution of male specific lethal 1 (MSL-1), a nuclear protein involved in dosage compensation in Drosophila melanogaster, which ensures that males with single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. Tomographic reconstructions of X-ray microscopic images were used to compute the local three-dimensional linear absorption coefficient revealing the arrangement of internal structures of Drosophila melanogaster cells. Combined with labelling techniques, nanotomography is a new technique to study the 3D distribution of selected proteins inside whole cells. We want to improve this technique with respect to resolution and specimen preparation. The resolution in the reconstruction can be significantly improved by reducing the angular step size to collect more viewing angles, which requires an automated data acquisition. In addition, fast-freezing with liquid ethane instead of cryogenic He gas will be applied to improve the vitrification of the hydrated samples. We also plan to apply cryo X-ray nanotomography in order to study different types of cells and their nuclear protein distributions

  18. Evaluation of diffuse large B-cell lymphoma patients with 64-slice multidetector computed tomography versus 18FDG positron emission tomography/computed tomography in initial staging and restaging after treatment.

    Science.gov (United States)

    Gómez León, Nieves; Vega, Gema; Rodríguez-Vigil Junco, Beatriz; Suevos Ballesteros, Carlos

    2018-04-25

    To prospectively compare the accuracy in initial staging and end-of-treatment restaging of diffuse large B-cell lymphoma (DLBCL) between 64-slice multidetector computed tomography (64MDCT) and 18FDG positron emission tomography/computed tomography (18FGD PET/CT) with intravenous contrast injection. Randomised and blind controlled clinical multicentric trial that included biopsy-proven DLBCL patients. Seventy-two patients from five different hospitals in the region of Madrid, Spain, were enrolled in the study between January 2012 and June 2015. Thirty-six were randomly allocated to 18FDG PET/TC and the other 36 to 64MDCT for initial staging and end-of-treatment restaging. A nuclear medicine physician and a radiologist independently analysed 18FDG PET/TC images and reached an agreement post-hoc. 64MDCT images were separately evaluated by a different radiologist. Every set of images was compared to the reference standard that included clinical data, complementary tests and follow-up. The study was approved by participating centres' ethics committees and written informed consent was obtained from all the participants. A good agreement was observed between both diagnostic techniques and the reference standard in initial staging [18FDG PET/CT (k=0.5) and 64MDCT (k=0.6)], although only the 18FDG PET/TC showed a good agreement with the reference standard for the end-of-treatment restaging (k=0.7). In DLBCL, both 18FDG PET/TC and 64MDCT have shown good agreement with the reference standard in initial staging. Nevertheless, 18FDG PET/CT has shown to be superior to 64MDCT in end-of-treatment response assessment. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  19. Treatment

    Directory of Open Access Journals (Sweden)

    Safaa M. Raghab

    2013-08-01

    The main goal of this study is to utilize a natural low cost material “as an accelerator additive to enhance the chemical treatment process using Alum coagulant and the accelerator substances were Perlite and Bentonite. The performance of the chemical treatment was enhanced using the accelerator substances with 90 mg/l Alum as a constant dose. Perlite gave better performance than the Bentonite effluent. The removal ratio for conductivity, turbidity, BOD and COD for Perlite was 86.7%, 87.4%, 89.9% and 92.8% respectively, and for Bentonite was 83.5%, 85.0%, 86.5% and 85.0% respectively at the same concentration of 40 mg/l for each.

  20. Human-Avatar Symbiosis for the Treatment of Auditory Verbal Hallucinations in Schizophrenia through Virtual/Augmented Reality and Brain-Computer Interfaces.

    Science.gov (United States)

    Fernández-Caballero, Antonio; Navarro, Elena; Fernández-Sotos, Patricia; González, Pascual; Ricarte, Jorge J; Latorre, José M; Rodriguez-Jimenez, Roberto

    2017-01-01

    This perspective paper faces the future of alternative treatments that take advantage of a social and cognitive approach with regards to pharmacological therapy of auditory verbal hallucinations (AVH) in patients with schizophrenia. AVH are the perception of voices in the absence of auditory stimulation and represents a severe mental health symptom. Virtual/augmented reality (VR/AR) and brain computer interfaces (BCI) are technologies that are growing more and more in different medical and psychological applications. Our position is that their combined use in computer-based therapies offers still unforeseen possibilities for the treatment of physical and mental disabilities. This is why, the paper expects that researchers and clinicians undergo a pathway toward human-avatar symbiosis for AVH by taking full advantage of new technologies. This outlook supposes to address challenging issues in the understanding of non-pharmacological treatment of schizophrenia-related disorders and the exploitation of VR/AR and BCI to achieve a real human-avatar symbiosis.

  1. Application of the PHREEQC geochemical computer model during the design and operation of UK mine water treatment schemes

    Energy Technology Data Exchange (ETDEWEB)

    Croxford, S.J.; England, A.; Jarvis, A.P. [IMC White Young Green Engineering and Environment, Sutton-in-Ashfield (United Kingdom)

    2004-07-01

    The UK Coal Authority operates more than 20 full-scale mine water treatment schemes. The PHREEQC geochemical model has been used during the design and operation of two of the UK Coal Authority's treatment systems to assess whether it is possible to more accurately predict the fate and behaviour of contaminants through the treatment process. These systems are at Frances Colliery, Fife, Scotland, and at Horden Colliery, County Durham, England. The characteristics of the mine water at these sites, and the treatment systems installed to remediate them, are described. At Frances Colliery the following issues have been investigated using the PHREEQC model: determination of optimum alkali dose rate; and investment of secondary mineralization that causes pipe fouling. At Horden Colliery areas investigated using the PHREEQC model are: prediction of sludge volume production for various alkali reagents; predication of the influence of elevated carbon dioxide partial pressures on alkali requirements; and influence of elevated chloride concentration on sludge characteristics and production. The results of the investigation are presented and discussed. The study suggests that geochemical modelling may be a useful tool in determining both the geochemical processes occurring within a mine water treatment system and ultimately the likely costs involved during the operation of a particular scheme. Plans for future work include further validation of the PHREEQC model predictions by careful sampling and analysis of water chemistry and secondary mineral phases through the treatment systems. In the future it is hoped that the PHREEQC model may become a useful tool in the design phase of mine water treatment systems. 7 refs., 8 tabs.

  2. Advanced Analytic Treatment and Efficient Computation of the Diffraction Integrals in the Extended Nijboer-Zernike Theory

    Science.gov (United States)

    van Haver, S.; Janssen, A. J. E. M.

    2013-07-01

    The computational methods for the diffraction integrals that occur in the Extended Nijboer-Zernike (ENZ-) approach to circular, aberrated, defocused optical systems are reviewed and updated. In the ENZ-approach, the Debye approximation of Rayleigh's integral for the through-focus, complex, point-spread function is evaluated in semi-analytic form. To this end, the generalized pupil function, comprising phase aberrations as well as amplitude non-uniformities, is assumed to be expanded into a series of Zernike circle polynomials, and the contribution of each of these Zernike terms to the diffraction integral is expressed in the form of a rapidly converging series (containing power functions and/or Bessel functions of various kinds). The procedure of expressing the through-focus point-spread function in terms of Zernike expansion coefficients of the pupil function can be reversed and has led to the ENZ-method of retrieval of pupil functions from measured through-focus (inte! nsity) point-spread functions. The review and update concern the computation for systems ranging from as basic as having low NA and small defocus parameter to high-NA systems, with vector fields and polarization, meant for imaging of extended objects into a multi-layered focal region. In the period 2002-2010, the evolution of the form of the diffraction integral (DI) was dictated by the agenda of the ENZ-team in which a next instance of the DI was handled by amending the computation scheme of the previous one. This has resulted into a variety of ad hoc measures, lack of transparency of the schemes, and sometimes prohibitively slow computer codes. It is the aim of the present paper to reconstruct the whole building of computation methods, using consistently more advanced mathematical tools. These tools are -explicit Zernike expansion of the focal factor in the DI, -Clebsch-Gordan coefficients for the omnipresent problem of linearizing products ofZernike circle polynomials, -recursions for Bessel

  3. Evaluation of the use of computed tomography versus conventional orthogonal X-ray simulation in the treatment of rectal cancer

    International Nuclear Information System (INIS)

    Darben, P.; Lim-Joon, D.; Chao, M.; Gibbs, P.; Tjandra, J.; Jones, I.T.

    2005-01-01

    The aim of this study is to compare and contrast the treatment fields designed using CT versus conventional orthogonal X-ray simulation in the treatment of patients with rectal cancer given preoperative chemotherapy and radiotherapy. Nine patients participated in this study. The coverage of treatment fields, the volume of treatment fields, and the position of the anorectal junction in relation to the inferior border of the obturator foramen as the delineator of the pelvic floor were evaluated in each patient using CT and conventional orthogonal X-ray simulation. The results demonstrated undercoverage of the anterior border of the lateral fields of up to 2.5 cm in seven of nine patients when conventional orthogonal X-ray simulation was compared to CT simulation. In addition, the inferior border of the obturator foramen proved to be a poor delineator of the pelvic floor with the anorectal junction situated up to 2 cm superiorly in seven of nine patients. In conclusion, CT simulation is superior to conventional orthogonal X-ray simulation when designing treatment fields for patients with rectal cancer Copyright (2005) Blackwell Publishing Asia Pty Ltd

  4. Root resorption diagnosed with cone beam computed tomography after 6 months of orthodontic treatment with fixed appliance and the relation to risk factors.

    Science.gov (United States)

    Makedonas, Dimitrios; Lund, Henrik; Gröndahl, Kerstin; Hansen, Ken

    2012-03-01

    To investigate root resorption after 6 months of active orthodontic treatment and its relation to possible risk factors. Ninety-seven patients (10-18 years) with a Class I malocclusion and crowding treated with fixed appliance and premolar extractions were examined with cone beam computed tomography before and after 6 months of active treatment. The exposure covered all teeth from first molar to first molar in both jaws. The Malmgren index was used to evaluate the degree of root resorption. Irregular root contour (score 1) was seen in most teeth already before active treatment, and therefore resorptions were registered only as score 2 (resorption) or higher. Minor root resorption was noted in 10% of the patients and severe root resorption, >2 mm (score 3) was found in four patients. Root resorption was more frequently seen in the upper jaw, especially the incisors. There was no statistically significant correlation of root resorption with any of the selected risk factors. After 6 months of treatment, clinically significant resorption was diagnosed in 4% of the patients, ie, in 96% of the patients the radiographic examination did not reveal any significant information. The selected risk factors did not have any impact on the amount of resorption after 6 months of active treatment.

  5. Computational Streetscapes

    Directory of Open Access Journals (Sweden)

    Paul M. Torrens

    2016-09-01

    Full Text Available Streetscapes have presented a long-standing interest in many fields. Recently, there has been a resurgence of attention on streetscape issues, catalyzed in large part by computing. Because of computing, there is more understanding, vistas, data, and analysis of and on streetscape phenomena than ever before. This diversity of lenses trained on streetscapes permits us to address long-standing questions, such as how people use information while mobile, how interactions with people and things occur on streets, how we might safeguard crowds, how we can design services to assist pedestrians, and how we could better support special populations as they traverse cities. Amid each of these avenues of inquiry, computing is facilitating new ways of posing these questions, particularly by expanding the scope of what-if exploration that is possible. With assistance from computing, consideration of streetscapes now reaches across scales, from the neurological interactions that form among place cells in the brain up to informatics that afford real-time views of activity over whole urban spaces. For some streetscape phenomena, computing allows us to build realistic but synthetic facsimiles in computation, which can function as artificial laboratories for testing ideas. In this paper, I review the domain science for studying streetscapes from vantages in physics, urban studies, animation and the visual arts, psychology, biology, and behavioral geography. I also review the computational developments shaping streetscape science, with particular emphasis on modeling and simulation as informed by data acquisition and generation, data models, path-planning heuristics, artificial intelligence for navigation and way-finding, timing, synthetic vision, steering routines, kinematics, and geometrical treatment of collision detection and avoidance. I also discuss the implications that the advances in computing streetscapes might have on emerging developments in cyber

  6. A case of temporal lobe epilepsy with improvement of clinical symptoms and single photon emission computed tomography findings after treatment with clonazepam.

    Science.gov (United States)

    Ide, M; Mizukami, K; Suzuki, T; Shiraishi, H

    2000-10-01

    A 26-year-old female presented psychomotor seizures, deja vu and amnestic syndrome after meningitis at the age of 14 years. Repeated electroencephalograms (EEG) demonstrated occasional spikes localized in the right temporal region in addition to a considerable amount of theta waves mainly in the right fronto-temporal region. Single photon emission computed tomography (SPECT) showed a marked hypoperfusion corresponding to the region in which the EEG showed abnormal findings, although magnetic resonance imaging (MRI) demonstrated no abnormal findings associated with the clinical features. Treatment with clonazepam in addition to sodium valproate resulted in a remarkable improvement of clinical symptoms (i.e. psychomotor seizures and deja vu), as well as of the EEG and SPECT findings. The present study suggests that SPECT is a useful method not only to determine the localization of regions associated with temporal lobe epilepsy but also to evaluate the effect of treatment in temporal lobe epilepsy.

  7. Development and validation of a computational model of the knee joint for the evaluation of surgical treatments for osteoarthritis.

    Science.gov (United States)

    Mootanah, R; Imhauser, C W; Reisse, F; Carpanen, D; Walker, R W; Koff, M F; Lenhoff, M W; Rozbruch, S R; Fragomen, A T; Dewan, Z; Kirane, Y M; Cheah, K; Dowell, J K; Hillstrom, H J

    2014-01-01

    A three-dimensional (3D) knee joint computational model was developed and validated to predict knee joint contact forces and pressures for different degrees of malalignment. A 3D computational knee model was created from high-resolution radiological images to emulate passive sagittal rotation (full-extension to 65°-flexion) and weight acceptance. A cadaveric knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligament-tuning process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element (FE) model. The model was validated by measured intra-articular force and pressure measurements. Percent full scale error between FE-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%, respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee model can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be further developed for subject-specific surgical planning.

  8. Computer modelling system of the chemical composition and treatment parameters influence on mechanical properties of structural steels

    OpenAIRE

    L.A. Dobrzański; R. Honysz

    2009-01-01

    Purpose: This paper presents Neuro-Lab. It is an authorship programme, which use algorithms of artificial intelligence for structural steels mechanical properties estimation.Design/methodology/approach: On the basis of chemical composition, parameters of heat and mechanical treatment and elements of geometrical shape and size this programme has the ability to calculate the mechanical properties of examined steel and introduce them as raw numeric data or in graphic as influence charts. Possibl...

  9. Role of spiral computed Tomography in the diagnosis and treatment planning of patients with colorectal cancer and peritoneal carcinomatosis

    International Nuclear Information System (INIS)

    Revura, A.P.; Fetsich, T.G.; Milyan, Yu.P.

    2015-01-01

    The results of CT of the abdomen and pelvis in 21 patients with colorectal cancer with peritoneal carcinomatosis were analysed. The study was compared with data obtained at surgical exploration. Location and size of peritoneal implants were evaluated according to peritoneal cancer index. The study shows a lack of sensitivity of single slice spiral CT for peritoneal carcinomatosis detection in patients with colorectal cancer and limited value of the method in planning of surgical treatment

  10. Usefulness of the computed tomography and magnetic resonance in evaluation of progress of treatment of the neoplasmatic diseases in children

    International Nuclear Information System (INIS)

    Myga-Porosiło, Jolanta; Borowiak, Hanna; Sraga, Wojciech; Jackowska, Zuzanna; Serafin, Magdalena; Kluczewska, Ewa

    2012-01-01

    Neoplastmatic diseases constitute about 1% diseases in children in Poland, what makes about 1200 new incidents during one year. Fast diagnosis in those illnesses is crucial in treatment results. The point of this work was to value usefulness of CT and MRI in diagnostics of neoplasmatic diseases in children. The retrospective study involved 121 children examined in CT and MRI because of suspicion or during treatment of neoplasmatic disease. Together 184 CT and 119 MRI examination were performed. Eventually in 106 children neoplasmatic disease was diagnosed. In 16 cases neoplasm was excluded. In the analyzed group of patients acute lymphoblastic and non lymphoblastic leukemia was diagnosed in 68 children (55.7%); among them mycosis was identified after radiological examinations in 7 cases (10.3%). 8 children (6.6%) with non Hodgkin lymphoma and 11 (9%) with Hodgkin lymphoma were examined. Nephroblastoma was found after MRI and CT in 6 cases (4.9%). Presence of tumors, that were classified histopatologically as PNET, was confirmed in 4 children. In 15 cases after MRI and CT neoplasmatic disease was excluded. Depending on the kind of sickness MRI and CT may fulfill basic or subsidiary role in diagnostic and estimating the progress of treatment in neoplasmatic diseases among children

  11. The Tarsoft software: A computer program to learn the elemental theory for the urban wastewater treatment; Tarsoft: programa de ordenador para el aprendizaje de la teoria basica sobre la depuracion de las aguas residuales urbanas

    Energy Technology Data Exchange (ETDEWEB)

    Parra Narvaez, R.; Baldasano Recio, J.M. [Universitat Politecnica de Catalunya. Barcelona (Spain)

    1998-12-31

    It` ve been developed a first version of the computer program Tarsoft, with the objective to be a Informatic contribution for the education and training of the knowledge about the urban wastewater treatment. This article describe in general form, the main characteristic of this computer program, the minimal hardware and software requirements, the theoretical topics than it include, the presentation form of the variety alfanumerical and graphical interactive information and design modules of the different treatment process. (Author) 20 refs.

  12. The diagnosis and conservative treatment of a complex type 3 dens invaginatus using cone beam computed tomography (CBCT) and 3D plastic models.

    Science.gov (United States)

    Kfir, A; Telishevsky-Strauss, Y; Leitner, A; Metzger, Z

    2013-03-01

    To investigate the use of 3D plastic models, printed from cone beam computed tomography (CBCT) data, for accurate diagnosis and conservative treatment of a complex case of dens invaginatus. A chronic apical abscess with a draining sinus tract was diagnosed during the treatment planning stage of orthodontic therapy. Radiographic examination revealed a large radiolucent area associated with an invaginated right maxillary central incisor, which was found to contain a vital pulp. The affected tooth was strategic in the dental arch. Conventional periapical radiographs provided only partial information about the invagination and its relationship with the main root canal and with the periapical tissues. A limited-volume CBCT scan of the maxilla did not show evidence of communication between the infected invagination and the pulp in the main root canal, which could explain the pulp vitality. A novel method was adopted to allow for instrumentation, disinfection and filling of the invagination, without compromising the vitality of the pulp in the complex root canal system. The CBCT data were used to produce precise 3D plastic models of the tooth. These models facilitated the treatment planning process and the trial of treatment approaches. This approach allowed the vitality of the pulp to be maintained in the complex root canal space of the main root canal whilst enabling the healing of the periapical tissues. Even when extensive periapical pathosis is associated with a tooth with type III dens invaginatus, pulp sensibility tests should be performed. CBCT is a diagnostic tool that may allow for the management of such teeth with complex anatomy. 3D printed plastic models may be a valuable aid in the process of assessing and planning effective treatment modalities and practicing them ex vivo before actually performing the clinical procedure. Unconventional technological approaches may be required for detailed treatment planning of complex cases of dens invaginatus. © 2012

  13. Computed tomography scan in supine and prone positions: an alternative method to detect intramural gas in emphysematous cystitis and to evaluate efficacy after adjuvant continuous intravesical irrigation treatment.

    Science.gov (United States)

    Cortés-González, Jeff R; Ortiz-Lara, Gerardo E; Salinas, Matías; Hernández-Galván, Fernando; Gómez-Guerra, Lauro S

    2013-04-01

    To evaluate the efficacy of continuous intravesical irrigation with saline plus amikacin as adjuvant therapy and to evaluate the computed tomography (CT) scan in supine and prone positions (CystoCT scan) as an alternative diagnostic and evaluation method of intramural gas in emphysematous cystitis (EC) before and after treatment. Consecutive patients with a diagnosis of EC who were hospitalized between March 2006 and January 2011 were investigated. The diagnosis was made by CystoCT scan. Treatment consisted of intravenous antibiotics, control of concomitant diseases, and placement of a 3-way urinary catheter for continuous irrigation of 500 mg of amikacin diluted in 1 l of saline given on days 0, 3, and 7. Treatment was considered successful when there was an absence of gas in the bladder wall, the urine culture was negative, there was clinical improvement, and there was an absence of toxicity. Eleven patients were hospitalized with a diagnosis of EC during the study period. Four were excluded from the study, 2 due to the lack of confirmation of the diagnosis with the CystoCT scan. Treatment was successful in all patients; for 6 (86%) this was achieved in 3 days and for 1 (14%) in 7 days. No toxicity was reported. Continuous intravesical irrigation with saline plus amikacin as adjuvant treatment of EC is an inexpensive, effective, and safe tool that might help conventional treatment and provide a rapid recovery. The CystoCT scan is an alternative method to diagnose and evaluate intramural gas in EC patients. These findings should be challenged in a randomized, multi-centre, placebo-controlled clinical trial.

  14. The value of three-dimensional helical computed tomography for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2016-03-01

    Full Text Available Objective: The aim of our study was to determine if there is any advantage of three-dimensional helical computed tomography (3D-HCT over intravenous urogram (IVU for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones. Methods: From June 2012 to January 2014, a total of 52 cases of lower pole renal stones underwent retrograde intrarenal surgery (RIRS in our center. All patients underwent a preoperative IVU and three-dimensional helical computed tomography urography (3D-CTU program to define the collecting system anatomy, manly concerning the following lower pole features; infundibu-lopelvic angle (IPA, infundibular length (IL, and infundibular width (IW. The examinations were performed in the same center of reference with a standardized method and with 3D-HCT Siemens Somaton Plus equipment. The measurements were performed by the same researcher, using a ruler and a square. Results: Based on clinical threshold difference of the anatomic factors on an IVU image to compare the difference between an IVU image and a 3D-CT image of 52 patients, the IPA was <30° when measured on intravenous pyelography (IVP for 21 patients. We found that with the IPA of <30° measured with IVP only 19% (4/21 were correctly classified in the same size category using 3D-HCT, whereas 81% (17/21 were upgraded to 40–50° on 3D-CT. This difference was significant between IVP and 3D-HCT. Conclusions: 3D-HCT has advantages over IVU when analyzing the morphometric and the morphological features of kidney lower pole spatial anatomy for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones. Keywords: Intravenous urogram, Computed tomography urography, Flexible ureterorenoscopy, Lower pole, Renal stones

  15. Three-dimensional cone-beam computed tomography: A new approach to the diagnosis and treatment planning of impacted mandibular third molars

    International Nuclear Information System (INIS)

    Kanazirska, P.; Yordanov, G.; Angelova, I.; Kanazirski, N.

    2017-01-01

    Cone Beam Computed Tomography (CBCT) is a relatively new method in dental practice which raises a more precise diagnosis and correct treatment plan. The image of the impacted teeth and surrounding structures with CBCT are with better quality and informativity than the conventional imaging-diagnostic methods . The use of CBCT to determine the ratio of the impacted teeth to the mandibular canal is necessary for the prevention of complications associated with iatrogenic trauma to the vascular- nerve bundle. The aim of this study was to determine the anatomic relationship between the roots of impacted third molars and mandibular canal using CBCT imaging. The studied patients with impacted third molars of the mandible are 127, aged 17 through 60.They were examined with Cone-beam Computed Tomography (CBCT). From the 195 impacted third molar with the - higher frequency are those in which the channel is below their roots-107 teeth (54.9%). The second frequency are the teeth where the channel is located lingually-57 (29.2%). Follow the teeth, in which the channel has a buccal location-25 (12.8%). With the lowest frequency are cases in which the mandibular canal is between the roots of impacted teeth-6 teeth (3.1%).At 132 teeth (67.7%) mandibular canal is at a distance of 1 mm. At 63 teeth (32.3%) the channel is at a distance of over 1 mm. The high resolution cuts in different planes and three-dimensional reconstructions made substantially as set forth preferred for different specialists in dentistry. Precise measurements of the bone around the mandibular canal prevent damage to neurovascular bundle. This makes the method preferred for planning appropriate treatment. Key words: Cone Beam Computed Tomography. Impacted Third Molars. Mandibular Canal [bg

  16. Computational modelling of radiotherapy treatment equipment, relationship between the intricate details of a radiotherapy treatment beam and its subsequent dose distributions

    International Nuclear Information System (INIS)

    Hug, B.H.; Ebert, M.A.; Woodward, R.

    2011-01-01

    Full text: As treatment planning and delivery technology continues to improve, physicists are faced with new IMRT QA challenges. A proposed solution is beam monitoring devices capable of measuring beam fluence modulation. However, information provided by such a device is only a surrogate of the true beam fluence. This work examined the relationship between the level of knowledge of beam fluence provided by such a device and the implication on dosimetry calculations. Phase space files obtained from the TAEA database for varying linac manufacturer and field sizes particle characteristics were modified and used as the source for a DOSXYZnrc Monte Carlo dose calculation in a water phantom. Dose representations were produced for the unmodified and modified dose files and the dose variations quantified. Results show that altering the particle directions had the most effect in the penumbral regions. Reduced knowledge regarding the particle spectra and contamination lead to marked differences in the dose build up region as well as off axis regions at depth. Current Fluence measurement devices could potentially be oversimplifying the relationship between the beam characteristics and the subsequent calculated dose distribution. Conclusion suggest if a fluence device is to be used for dosimetry purposes, the device must be capable of resolving beam characteristics. The limit of information required to be known to accurately predict a dose distribution will be determined and used in conjunction with Monte Carlo simulations to investigate the response of novel detector geometries to such particle characteristics.

  17. Long-term Risedronate Treatment Normalizes Mineralization and Continues to Preserve Trabecular Architecture: Sequential Triple Biopsy Studies with Micro-Computed Tomography

    International Nuclear Information System (INIS)

    Borah, B.; Dufresne, T.; Ritman, E.; Jorgensen, S.; Liu, S.; Chmielewski, P.; Phipps, R.; Zhou, X.; Sibonga, J.; Turner, R.

    2006-01-01

    The objective of the study was to assess the time course of changes in bone mineralization and architecture using sequential triple biopsies from women with postmenopausal osteoporosis (PMO) who received long-term treatment with risedronate. Transiliac biopsies were obtained from the same subjects (n = 7) at baseline and after 3 and 5 years of treatment with 5 mg daily risedronate. Mineralization was measured using 3-dimensional (3D) micro-computed tomography (CT) with synchrotron radiation and was compared to levels in healthy premenopausal women (n = 12). Compared to the untreated PMO women at baseline, the premenopausal women had higher average mineralization (Avg-MIN) and peak mineralization (Peak-MIN) by 5.8% (P = 0.003) and 8.0% (P = 0.003), respectively, and lower ratio of low to high-mineralized bone volume (BMR-V) and surface area (BMR-S) by 73.3% (P = 0.005) and 61.7% (P 0.003), respectively. Relative to baseline, 3 years of risedronate treatment significantly increased Avg-MIN (4.9 ± 1.1%, P = 0.016) and Peak-MIN (6.2 ± 1.5%, P = 0.016), and significantly decreased BMR-V (-68.4 ± 7.3%, P = 0.016) and BMR-S (-50.2 ± 5.7%, P = 0.016) in the PMO women. The changes were maintained at the same level when treatment was continued up to 5 years. These results are consistent with the significant reduction of turnover observed after 3 years of treatment and which was similarly maintained through 5 years of treatment. Risedronate restored the degree of mineralization and the ratios of low- to high-mineralized bone to premenopausal levels after 3 years of treatment, suggesting that treatment reduced bone turnover in PMO women to healthy premenopausal levels. Conventional micro-CT analysis further demonstrated that bone volume (BV/TV) and trabecular architecture did not change from baseline up to 5 years of treatment, suggesting that risedronate provided long-term preservation of trabecular architecture in the PMO women. Overall, risedronate provided sustained

  18. The Study of Factors Influencing on Orthodontic Treatment Difficulty of Impacted Maxillary Canine with Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    A.F. Miresmaeili

    2012-10-01

    Full Text Available Introduction & Objective: Maxillary canines are esthetically and functionally important, but patients with impacted maxillary canines are perceived to be more difficult and time-consuming to treat than the average orthodontic patient. The aim of this study was to define orthodontic Treatment Difficulty Index (TDI of impacted maxillary canine with CBCT according to experts' opinions.Materials & Methods: In this cross sectional study, nine variables in CBCT of thirty six consecutive patients with 50 impacted maxillary canines were measured using Dolphin 3D. The related 3D and 2D pictures and the measured data were uploaded on a website. Ten orthodontists were asked to judge the difficulty of bringing the impacted canine to occlusal plane from 1 to 10 (1 = easy, 10 = extremely difficult.Then, they were also asked to evaluate the effect of each variable on treatment from 1 to 5 (1= very low, 5= very high. Random effect linear regression was used in exploration stage and then simple linear regression was used for the application of the model.Results: The patients mean age was 19.08 ± 5.8 years. Mean clinical experience of examiners was 22.7 ±12.02 years. Three variables were deleted at exploration stage and two other in model application stage. Vertical distance to the occlusal plane (P=0.000, overlap in frontal view (P=0.000, angulations of the canine to the occlusal plan (P=0.029, dilacerations (P=0.000, and rotation (P=0.029 had a significant relationship with TDI.Conclusion: Treatment difficulty of impacted maxillary canines could be predicted quantitatively by measuring variables in CBCT.(Sci J Hamadan Univ Med Sci 2012;19(3:30-35

  19. Autoblocking dose-limiting normal structures within a radiation treatment field: 3-D computer optimization of 'unconventional' field arrangements

    International Nuclear Information System (INIS)

    Bates, Brian A.; Cullip, Timothy J.; Rosenman, Julian G.

    1995-01-01

    Purpose/Objective: To demonstrate that one can obtain a homogeneous dose distribution within a specified gross tumor volume (GTV) while severely limiting the dose to a structure surrounded by that tumor volume. We present three clinical examples below. Materials and Methods: Using planning CT scans from previously treated patients, we designed variety of radiation treatment plans in which the dose-critical normal structure was blocked, even if it meant blocking some of the tumor. To deal with the resulting dose inhomogeneities within the tumor, we introduced 3D compensation. Examples presented here include (1) blocking the spinal cord segment while treating an entire vertebral body, (2) blocking both kidneys while treating the entire peritoneal cavity, and (3) blocking one parotid gland while treating the oropharynx in its entirety along with regional nodes. A series of multiple planar and non-coplanar beam templates with automatic anatomic blocking and field shaping were designed for each scenario. Three-dimensional compensators were designed that gave the most homogeneous dose-distribution for the GTV. For each beam, rays were cast from the beam source through a 2D compensator grid and out through the tumor. The average tumor dose along each ray was then used to adjust the compensator thickness over successive iterations to achieve a uniform average dose. DVH calculations for the GTV, normal structures, and the 'auto-blocked' structure were made and used for inter-plan comparisons. Results: These optimized treatment plans successfully decreased dose to the dose-limiting structure while at the same time preserving or even improving the dose distribution to the tumor volume as compared to traditional treatment plans. Conclusion: The use of 3D compensation allows one to obtain dose distributions that are, theoretically, at least, far superior to those in common clinical use. Sensible beam templates, auto-blocking, auto-field shaping, and 3D compensators form a

  20. Percutaneous ethanol injection under interventional radiographic computed tomography-fluoroscopic guidance for the treatment of small hepatocellular carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Furuse, Junji; Satake, Mitsuo; Iwasaki, Masahiko; Sekiguchi, Ryuzo; Moriyama, Noriyuki; Yoshino, Masahiro [National Cancer Center, Kashiwa, Chiba (Japan). Hospital East

    1998-04-01

    Some small hepatocellular carcinoma (HCC) lesions show as tumor stains by dynamic CT, but cannot be detected by ultrasonography. Percutaneous ethanol injection (PEI) is effective for treating small HCC lesions, but lack of adequate visualization of some lesions can limit its use. In this study, interventional radiographic, CT-fluoroscopically-guided PEI was performed as a new method for treating small HCC lesions that were difficult to detect by ultrasonography. Interventional radiographic, CT-fluoroscopically-guided PEI was performed on 11 patients (12 lesions) with HCC lesions measuring 2 cm or less in diameter. A thin needle was introduced into each tumor under CT-fluoroscopic guidance, with injection of contrast medium into the dominant hepatic artery. While lesions were observed using CT-fluoroscopy with the arteriogram, absolute ethanol was injected into the tumors. The ethanol injection rate and volume were monitored by observation of loss of tumor staining during real-time CT angiography. Needle introduction was successful in all 12 lesions, and disappearance of tumor staining was immediately observed on CT images after ethanol injection. Complications noted after treatment were local abdominal pain in all 11 patients, a slight fever in 9 patients, pneumothorax, right pleural effusion, and ascites, each in 1 patient. No other serious complications were observed. Interventional radiographic, CT-fluoroscopically-guided PEI is effective in the treatment of small HCC lesions, which are difficult to show by ultrasonography and treat by conventional PEI. (author)

  1. The advantages of computed tomography over conventional x-ray examination in the treatment of cervical spinal diseases

    International Nuclear Information System (INIS)

    Shin, Hideo; Yamaura, Akira; Makino, Hiroyasu

    1982-01-01

    Computed tomography (CT) of the cervical spinal column was carried out in 42 patients using a General Electric CT/T of a Toshiba TCT60 Type A scanner. There were 22 cervical disk lesions, 4 spinal neoplasms, 6 narrow spinal canals with or without ossification of posterior longitudinal ligament, 2 syringomyelias, 6 traumas and 2 Arnold-Chiari malformations. In all patients, CT-examination followed conventional spinal X-ray studies. Correlation between the CT and conventional X-ray findings revealed the better diagnostic capability of the CT. For example, the measured midline sagittal diameter of the spinal canal in a patient with the narrowest canal in this series was 7.4 mm on the CT and 9.6 mm on the conventioned plain film at the C 5 level. To know the precise sagittal diameter of the cord itself, CT myelography (CTM) is indispensable. CTM is useful in determining the nature of the disease, the risk and approach of surgery, and for evaluation after the surgical procedure. Although the range of motion of cervical joints and intervertebral foramen are visible with conventional films, the size and extension of a tumor, the degree of bony errosion and the spinal subarachnoid space can be precisely identified only by CT. CT study of the spine and spinal cord is a simple procedure and less likely to produce complication, even with CTM, although there are certain limitations in the examination which are also presented. (author)

  2. LIKELIHOOD-FREE COSMOLOGICAL INFERENCE WITH TYPE Ia SUPERNOVAE: APPROXIMATE BAYESIAN COMPUTATION FOR A COMPLETE TREATMENT OF UNCERTAINTY

    Energy Technology Data Exchange (ETDEWEB)

    Weyant, Anja; Wood-Vasey, W. Michael [Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), Physics and Astronomy Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Schafer, Chad, E-mail: anw19@pitt.edu [Department of Statistics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

    2013-02-20

    Cosmological inference becomes increasingly difficult when complex data-generating processes cannot be modeled by simple probability distributions. With the ever-increasing size of data sets in cosmology, there is an increasing burden placed on adequate modeling; systematic errors in the model will dominate where previously these were swamped by statistical errors. For example, Gaussian distributions are an insufficient representation for errors in quantities like photometric redshifts. Likewise, it can be difficult to quantify analytically the distribution of errors that are introduced in complex fitting codes. Without a simple form for these distributions, it becomes difficult to accurately construct a likelihood function for the data as a function of parameters of interest. Approximate Bayesian computation (ABC) provides a means of probing the posterior distribution when direct calculation of a sufficiently accurate likelihood is intractable. ABC allows one to bypass direct calculation of the likelihood but instead relies upon the ability to simulate the forward process that generated the data. These simulations can naturally incorporate priors placed on nuisance parameters, and hence these can be marginalized in a natural way. We present and discuss ABC methods in the context of supernova cosmology using data from the SDSS-II Supernova Survey. Assuming a flat cosmology and constant dark energy equation of state, we demonstrate that ABC can recover an accurate posterior distribution. Finally, we show that ABC can still produce an accurate posterior distribution when we contaminate the sample with Type IIP supernovae.

  3. LIKELIHOOD-FREE COSMOLOGICAL INFERENCE WITH TYPE Ia SUPERNOVAE: APPROXIMATE BAYESIAN COMPUTATION FOR A COMPLETE TREATMENT OF UNCERTAINTY

    International Nuclear Information System (INIS)

    Weyant, Anja; Wood-Vasey, W. Michael; Schafer, Chad

    2013-01-01

    Cosmological inference becomes increasingly difficult when complex data-generating processes cannot be modeled by simple probability distributions. With the ever-increasing size of data sets in cosmology, there is an increasing burden placed on adequate modeling; systematic errors in the model will dominate where previously these were swamped by statistical errors. For example, Gaussian distributions are an insufficient representation for errors in quantities like photometric redshifts. Likewise, it can be difficult to quantify analytically the distribution of errors that are introduced in complex fitting codes. Without a simple form for these distributions, it becomes difficult to accurately construct a likelihood function for the data as a function of parameters of interest. Approximate Bayesian computation (ABC) provides a means of probing the posterior distribution when direct calculation of a sufficiently accurate likelihood is intractable. ABC allows one to bypass direct calculation of the likelihood but instead relies upon the ability to simulate the forward process that generated the data. These simulations can naturally incorporate priors placed on nuisance parameters, and hence these can be marginalized in a natural way. We present and discuss ABC methods in the context of supernova cosmology using data from the SDSS-II Supernova Survey. Assuming a flat cosmology and constant dark energy equation of state, we demonstrate that ABC can recover an accurate posterior distribution. Finally, we show that ABC can still produce an accurate posterior distribution when we contaminate the sample with Type IIP supernovae.

  4. User's manual of a supporting system for treatment planning in boron neutron capture therapy. JAERI computational dosimetry system

    International Nuclear Information System (INIS)

    Kumada, Hiroaki; Torii, Yoshiya

    2002-09-01

    A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimensional head model of a patient by using CT and MRI images and that generates a input data file automatically for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patient's head is able to be made easily. The three-dimensional head image is editable to simulate the state of a head after its surgical processes such as skin flap opening and bone removal for the BNCT with craniotomy that are being performed in Japan. JCDS can provide information for the Patient Setting System to set the patient in an actual irradiation position swiftly and accurately. This report describes basic design and procedure of dosimetry, operation manual, data and library structure for JCDS (ver.1.0). (author)

  5. User's manual of a supporting system for treatment planning in boron neutron capture therapy. JAERI computational dosimetry system

    CERN Document Server

    Kumada, H

    2002-01-01

    A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimensional head model of a patient by using CT and MRI images and that generates a input data file automatically for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patient's head is able to be made easily. The three-dimensional head image is editable to ...

  6. Advantages of computed tomography over conventional x-ray examination in the treatment of cervical spinal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hideo; Yamaura, Akira; Makino, Hiroyasu (Chiba Univ. (Japan). School of Medicine)

    1982-07-01

    Computed tomography (CT) of the cervical spinal column was carried out in 42 patients using a General Electric CT/T of a Toshiba TCT60 Type A scanner. There were 22 cervical disk lesions, 4 spinal neoplasms, 6 narrow spinal canals with or without ossification of posterior longitudinal ligament, 2 syringomyelias, 6 traumas and 2 Arnold-Chiari malformations. In all patients, CT-examination followed conventional spinal X-ray studies. Correlation between the CT and conventional X-ray findings revealed the better diagnostic capability of the CT. For example, the measured midline sagittal diameter of the spinal canal in a patient with the narrowest canal in this series was 7.4 mm on the CT and 9.6 mm on the conventioned plain film at the C/sub 5/ level. To know the precise sagittal diameter of the cord itself, CT myelography (CTM) is indispensable. CTM is useful in determining the nature of the disease, the risk and approach of surgery, and for evaluation after the surgical procedure. Although the range of motion of cervical joints and intervertebral foramen are visible with conventional films, the size and extension of a tumor, the degree of bony errosion and the spinal subarachnoid space can be precisely identified only by CT. CT study of the spine and spinal cord is a simple procedure and less likely to produce complication, even with CTM, although there are certain limitations in the examination which are also presented.

  7. Use of cone-beam computed tomography in diagnosing and treating endodontic treatment failure: A case study

    Directory of Open Access Journals (Sweden)

    Gloria Lee

    2017-01-01

    Full Text Available The use of cone-beam computed tomography (CBCT as a complementary imaging modality applies to various clinical situations that with conventional two-dimensional radiographs alone may pose diagnostic challenges. These challenges include but are not limited to locating missed canals in endodontic retreatment and diagnosing the presence of lesions such as resorption, periapical bone defects, root fractures, and perforations. In this study, we present a case of an asymptomatic apical periodontitis that was incidentally found on a panoramic radiograph. Analyses based on panoramic and periapical radiographs and clinical examinations were insufficient for definitive diagnosis, which necessitated the use of CBCT. The CBCT scan allowed identification of the cause of the apical disease, an unfilled mesiolingual canal in previously root canal treated left mandibular second molar, as well as the extent of the lesion. We also explore the diagnostic challenges in using traditional two-dimensional radiographs only, the challenges in locating root canals in mandibular second molars, and risks and benefits in using CBCT.

  8. Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer.

    Science.gov (United States)

    Schinagl, Dominic A X; Vogel, Wouter V; Hoffmann, Aswin L; van Dalen, Jorn A; Oyen, Wim J; Kaanders, Johannes H A M

    2007-11-15

    Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may improve definition of the gross tumor volume (GTV). In this study, five methods for tumor delineation on FDG-PET are compared with CT-based delineation. Seventy-eight patients with Stages II-IV squamous cell carcinoma of the head and neck area underwent coregistered CT and FDG-PET. The primary tumor was delineated on CT, and five PET-based GTVs were obtained: visual interpretation, applying an isocontour of a standardized uptake value of 2.5, using a fixed threshold of 40% and 50% of the maximum signal intensity, and applying an adaptive threshold based on the signal-to-background ratio. Absolute GTV volumes were compared, and overlap analyses were performed. The GTV method of applying an isocontour of a standardized uptake value of 2.5 failed to provide successful delineation in 45% of cases. For the other PET delineation methods, volume and shape of the GTV were influenced heavily by the choice of segmentation tool. On average, all threshold-based PET-GTVs were smaller than on CT. Nevertheless, PET frequently detected significant tumor extension outside the GTV delineated on CT (15-34% of PET volume). The choice of segmentation tool for target-volume definition of head and neck cancer based on FDG-PET images is not trivial because it influences both volume and shape of the resulting GTV. With adequate delineation, PET may add significantly to CT- and physical examination-based GTV definition.

  9. Comparison of Five Segmentation Tools for 18F-Fluoro-Deoxy-Glucose-Positron Emission Tomography-Based Target Volume Definition in Head and Neck Cancer

    International Nuclear Information System (INIS)

    Schinagl, Dominic A.X.; Vogel, Wouter V.; Hoffmann, Aswin L.; Dalen, Jorn A. van; Oyen, Wim J.; Kaanders, Johannes H.A.M.

    2007-01-01

    Purpose: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with 18 F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may improve definition of the gross tumor volume (GTV). In this study, five methods for tumor delineation on FDG-PET are compared with CT-based delineation. Methods and Materials: Seventy-eight patients with Stages II-IV squamous cell carcinoma of the head and neck area underwent coregistered CT and FDG-PET. The primary tumor was delineated on CT, and five PET-based GTVs were obtained: visual interpretation, applying an isocontour of a standardized uptake value of 2.5, using a fixed threshold of 40% and 50% of the maximum signal intensity, and applying an adaptive threshold based on the signal-to-background ratio. Absolute GTV volumes were compared, and overlap analyses were performed. Results: The GTV method of applying an isocontour of a standardized uptake value of 2.5 failed to provide successful delineation in 45% of cases. For the other PET delineation methods, volume and shape of the GTV were influenced heavily by the choice of segmentation tool. On average, all threshold-based PET-GTVs were smaller than on CT. Nevertheless, PET frequently detected significant tumor extension outside the GTV delineated on CT (15-34% of PET volume). Conclusions: The choice of segmentation tool for target-volume definition of head and neck cancer based on FDG-PET images is not trivial because it influences both volume and shape of the resulting GTV. With adequate delineation, PET may add significantly to CT- and physical examination-based GTV definition

  10. Computational models can predict response to HIV therapy without a genotype and may reduce treatment failure in different resource-limited settings.

    Science.gov (United States)

    Revell, A D; Wang, D; Wood, R; Morrow, C; Tempelman, H; Hamers, R L; Alvarez-Uria, G; Streinu-Cercel, A; Ene, L; Wensing, A M J; DeWolf, F; Nelson, M; Montaner, J S; Lane, H C; Larder, B A

    2013-06-01

    Genotypic HIV drug-resistance testing is typically 60%-65% predictive of response to combination antiretroviral therapy (ART) and is valuable for guiding treatment changes. Genotyping is unavailable in many resource-limited settings (RLSs). We aimed to develop models that can predict response to ART without a genotype and evaluated their potential as a treatment support tool in RLSs. Random forest models were trained to predict the probability of response to ART (≤400 copies HIV RNA/mL) using the following data from 14 891 treatment change episodes (TCEs) after virological failure, from well-resourced countries: viral load and CD4 count prior to treatment change, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. Models were assessed by cross-validation during development, with an independent set of 800 cases from well-resourced countries, plus 231 cases from Southern Africa, 206 from India and 375 from Romania. The area under the receiver operating characteristic curve (AUC) was the main outcome measure. The models achieved an AUC of 0.74-0.81 during cross-validation and 0.76-0.77 with the 800 test TCEs. They achieved AUCs of 0.58-0.65 (Southern Africa), 0.63 (India) and 0.70 (Romania). Models were more accurate for data from the well-resourced countries than for cases from Southern Africa and India (P < 0.001), but not Romania. The models identified alternative, available drug regimens predicted to result in virological response for 94% of virological failures in Southern Africa, 99% of those in India and 93% of those in Romania. We developed computational models that predict virological response to ART without a genotype with comparable accuracy to genotyping with rule-based interpretation. These models have the potential to help optimize antiretroviral therapy for patients in RLSs where genotyping is not generally available.

  11. Contouring and Constraining Bowel on a Full-Bladder Computed Tomography Scan May Not Reflect Treatment Bowel Position and Dose Certainty in Gynecologic External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yaparpalvi, Ravindra, E-mail: ryaparpa@montefiore.org; Mehta, Keyur J.; Bernstein, Michael B.; Kabarriti, Rafi; Hong, Linda X.; Garg, Madhur K.; Guha, Chandan; Kalnicki, Shalom; Tomé, Wolfgang A.

    2014-11-15

    Purpose: To evaluate, in a gynecologic cancer setting, changes in bowel position, dose-volume parameters, and biological indices that arise between full-bladder (FB) and empty-bladder (EB) treatment situations; and to evaluate, using cone beam computed tomography (CT), the validity of FB treatment presumption. Methods and Materials: Seventeen gynecologic cancer patients were retrospectively analyzed. Empty-bladder and FB CTs were obtained. Full-bladder CTs were used for planning and dose optimization. Patients were given FB instructions for treatment. For the study purpose, bowel was contoured on the EB CTs for all patients. Bowel position and volume changes between FB and EB states were determined. Full-bladder plans were applied on EB CTs for determining bowel dose-volume changes in EB state. Biological indices (generalized equivalent uniform dose and normal tissue complication probability) were calculated and compared between FB and EB. Weekly cone beam CT data were available in 6 patients to assess bladder volume at treatment. Results: Average (±SD) planned bladder volume was 299.7 ± 68.5 cm{sup 3}. Median bowel shift in the craniocaudal direction between FB and EB was 12.5 mm (range, 3-30 mm), and corresponding increase in exposed bowel volume was 151.3 cm{sup 3} (range, 74.3-251.4 cm{sup 3}). Absolute bowel volumes receiving 45 Gy were higher for EB compared with FB (mean 328.0 ± 174.8 vs 176.0 ± 87.5 cm{sup 3}; P=.0038). Bowel normal tissue complication probability increased 1.5× to 23.5× when FB planned treatments were applied in the EB state. For the study, the mean percentage value of relative bladder volume at treatment was 32%. Conclusions: Full-bladder planning does not necessarily translate into FB treatments, with a patient tendency toward EB. Given the uncertainty in daily control over bladder volume for treatment, we strongly recommend a “planning-at-risk volume bowel” (PRV{sub B}owel) concept to account for bowel motion

  12. Displacement of structures in the thorax from expiration to inspiration as estimated by computed tomography and a 3-D treatment planning system

    International Nuclear Information System (INIS)

    Garmon, Pamela; Huang, David; Lutz, Steve; Zwicker, Robert

    1996-01-01

    Purpose/Objective: The spread of image based three dimensional treatment planning and conformal radiotherapy have brought new attention to the problems of patient motion during treatment. Recent studies of the effects of breathing on the motion of internal structures have led to the suggestion that gated irradiation might improve the therapeutic benefits of conformal therapy. In the present work we investigate the displacement of tumor and other structures in the thorax with breathing in order to assess further the potential benefit of gating in the treatment of lung tumors. Materials and Methods: Thoracic CT scans were obtained for patients immediately after inspiration and after expiration. Tumor positions were assessed by computing the centers of the outlined volumes for both inspiration and expiration. Effects of breathing motion along the longitudinal direction were evaluated by using a three dimensional treatment planning system to measure the distances between scans where the top of the diaphragm was present. Displacement within the transverse direction was assessed by measuring the positions of the field skin markers, the aorta and the esophagus. Results: Movement of the centers of the tumor volumes as computed by reconstructed volumes was measured to be 0.7-1.2cm. The magnitude of this movement was greatest for tumors in the mid to lower region of the lung and was primarily in the direction of superior to inferior combined with anterior to posterior. Displacement of the diaphragm ranged 1-3 cm with breathing. Displacement of the aorta and esophagus was measured to be 0.2-1.5 cm. Movement of these structures was only analyzed transversely and showed displacement to the patients' left and posterior upon expiration. The magnitude did not appear to correlate with position relative to the diaphragm. Patients with less diaphragm movement also had smaller tidal volumes and conversely, patients with larger diaphragm displacement had greater tidal volumes

  13. Quantification of Mediastinal and Hilar Lymph Node Movement Using Four-Dimensional Computed Tomography Scan: Implications for Radiation Treatment Planning

    International Nuclear Information System (INIS)

    Sher, David J.; Wolfgang, John A.; Niemierko, Andrzej; Choi, Noah C.

    2007-01-01

    Purpose: To quantitatively describe mediastinal and hilar lymph node movement in patients with lymph node-positive lung cancer. Methods and Materials: Twenty-four patients with lung cancer who underwent four-dimensional computed tomography scanning at Massachusetts General Hospital were included in the study. The maximum extent of superior motion of the superior border was measured, as well as the maximum inferior movement of the inferior border. The average of these two values is defined as the peak-to-peak movement. This process was repeated for mediolateral (ML) and anterior-posterior (AP) movement. Linear regression was used to determine lymph node characteristics associated with peak-to-peak movement. Various uniform expansions were investigated to determine the expansion margins necessary to ensure complete internal target volume (ITV) coverage. Results: The mean peak-to-peak displacements of paratracheal lymph nodes were 4 mm (craniocaudal [CC]), 2 mm (ML), and 2 mm (AP). For subcarinal lymph nodes, the mean peak-to-peak movements were 6 mm (CC), 4 mm (ML), and 2 mm (AP). The mean peak-to-peak displacements of hilar lymph nodes were 7 mm (CC), 1 mm (ML), and 4 mm (AP). On multivariate analysis, lymph node station and lymph node size were significantly related to peak-to-peak movement. Expansions of 8 mm for paratracheal nodes and 13 mm for subcarinal and hilar nodes would have been necessary to cover the ITV of 95% of these nodal masses. Conclusions: Subcarinal and hilar lymph nodes may move substantially throughout the respiratory cycle. In the absence of patient-specific information on nodal motion, expansions of at least 8 mm, 13 mm, and 13 mm should be considered to cover the ITV of paratracheal, subcarinal, and hilar lymph nodes, respectively

  14. Exploring the efficacy of endoscopic ventriculostomy for hydrocephalus treatment via a multicompartmental poroelastic model of CSF transport: a computational perspective.

    Directory of Open Access Journals (Sweden)

    John C Vardakis

    Full Text Available This study proposes the implementation of a Multiple-Network Poroelastic Theory (MPET model coupled with finite-volume computational fluid dynamics for the purpose of studying, in detail, the effects of obstructing CSF transport within an anatomically accurate cerebral environment. The MPET representation allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood, in an integral and comprehensive manner. A key novelty in the model is the amalgamation of anatomically accurate choroid plexuses with their feeding arteries and a simple relationship relaxing the constraint of a unique permeability for the CSF compartment. This was done in order to account for the Aquaporin-4-mediated swelling characteristics. The aim of this varying permeability compartment was to bring to light a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF into the blood system. This model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO. The implications of treating such a clinical condition with the aid of endoscopic third (ETV and endoscopic fourth (EFV ventriculostomy are considered. We observed peak CSF velocities in the aqueduct of the order of 15.6 cm/s in the healthy case, 45.4 cm/s and 72.8 cm/s for the mild and severe cases respectively. The application of ETV reduced the aqueductal velocity to levels around 16-17 cm/s. Ventricular displacement, CSF pressure, wall shear stress (WSS and pressure difference between lateral and fourth ventricles (ΔP increased with applied stenosis, and subsequently dropped to nominal levels with the application of ETV. The greatest reversal of the effects of atresia come by opting for ETV rather than the more complicated procedure of EFV.

  15. Early Chest Computed Tomography Scan to Assist Diagnosis and Guide Treatment Decision for Suspected Community-acquired Pneumonia.

    Science.gov (United States)

    Claessens, Yann-Erick; Debray, Marie-Pierre; Tubach, Florence; Brun, Anne-Laure; Rammaert, Blandine; Hausfater, Pierre; Naccache, Jean-Marc; Ray, Patrick; Choquet, Christophe; Carette, Marie-France; Mayaud, Charles; Leport, Catherine; Duval, Xavier

    2015-10-15

    Clinical decision making relative to community-acquired pneumonia (CAP) diagnosis is difficult. Chest radiograph is key in establishing parenchymal lung involvement. However, radiologic performance may lead to misdiagnosis, rendering questionable the use of chest computed tomography (CT) scan in patients with clinically suspected CAP. To assess whether early multidetector chest CT scan affects diagnosis and management of patients visiting the emergency department with suspected CAP. A total of 319 prospectively enrolled patients with clinically suspected CAP underwent multidetector chest CT scan within 4 hours. CAP diagnosis probability (definite, probable, possible, or excluded) and therapeutic plans (antibiotic initiation/discontinuation, hospitalization/discharge) were established by emergency physicians before and after CT scan results. The adjudication committee established the final CAP classification on Day 28. Chest radiograph revealed a parenchymal infiltrate in 188 patients. CAP was initially classified as definite in 143 patients (44.8%), probable or possible in 172 (53.8%), and excluded in 4 (1.2%). CT scan revealed a parenchymal infiltrate in 40 (33%) of the patients without infiltrate on chest radiograph and excluded CAP in 56 (29.8%) of the 188 with parenchymal infiltrate on radiograph. CT scan modified classification in 187 (58.6%; 95% confidence interval, 53.2-64.0), leading to 50.8% definite CAP and 28.8% excluded CAP, and 80% of modifications were in accordance with adjudication committee classification. Because of CT scan, antibiotics were initiated in 51 (16%) and discontinued in 29 (9%), and hospitalization was decided in 22 and discharge in 23. In CAP-suspected patients visiting the emergency unit, early CT scan findings complementary to chest radiograph markedly affect both diagnosis and clinical management. Clinical trial registered with www.clinicaltrials.gov (NCT 01574066).

  16. Olfactory neuroblastoma: the long-term outcome and late toxicity of multimodal therapy including radiotherapy based on treatment planning using computed tomography

    International Nuclear Information System (INIS)

    Mori, Takashi; Onimaru, Rikiya; Onodera, Shunsuke; Tsuchiya, Kazuhiko; Yasuda, Koichi; Hatakeyama, Hiromitsu; Kobayashi, Hiroyuki; Terasaka, Shunsuke; Homma, Akihiro; Shirato, Hiroki

    2015-01-01

    Olfactory neuroblastoma (ONB) is a rare tumor originating from olfactory epithelium. Here we retrospectively analyzed the long-term treatment outcomes and toxicity of radiotherapy for ONB patients for whom computed tomography (CT) and three-dimensional treatment planning was conducted to reappraise the role of radiotherapy in the light of recent advanced technology and chemotherapy. Seventeen patients with ONB treated between July 1992 and June 2013 were included. Three patients were Kadish stage B and 14 were stage C. All patients were treated with radiotherapy with or without surgery or chemotherapy. The radiation dose was distributed from 50 Gy to 66 Gy except for one patient who received 40 Gy preoperatively. The median follow-up time was 95 months (range 8–173 months). The 5-year overall survival (OS) and relapse-free survival (RFS) rates were estimated at 88% and 74%, respectively. Five patients with stage C disease had recurrence with the median time to recurrence of 59 months (range 7–115 months). Late adverse events equal to or above Grade 2 in CTCAE v4.03 were observed in three patients. Multimodal therapy including radiotherapy with precise treatment planning based on CT simulation achieved an excellent local control rate with acceptable toxicity and reasonable overall survival for patients with ONB

  17. Evidence for excited-state intramolecular proton transfer in 4-chlorosalicylic acid from combined experimental and computational studies: Quantum chemical treatment of the intramolecular hydrogen bonding interaction

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bijan Kumar [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India); Guchhait, Nikhil, E-mail: nikhil.guchhait@rediffmail.com [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Experimental and computational studies on the photophysics of 4-chlorosalicylic acid. Black-Right-Pointing-Pointer Spectroscopically established ESIPT reaction substantiated by theoretical calculation. Black-Right-Pointing-Pointer Quantum chemical treatment of IMHB unveils strength, nature and directional nature. Black-Right-Pointing-Pointer Superiority of quantum chemical treatment of H-bond over geometric criteria. Black-Right-Pointing-Pointer Role of H-bond as a modulator of aromaticity. -- Abstract: The photophysical study of a pharmaceutically important chlorine substituted derivative of salicylic acid viz., 4-chlorosalicylic acid (4ClSA) has been carried out by steady-state absorption, emission and time-resolved emission spectroscopy. A large Stokes shifted emission band with negligible solvent polarity dependence marks the spectroscopic signature of excited-state intramolecular proton transfer (ESIPT) reaction in 4ClSA. Theoretical calculation by ab initio and Density Functional Theory methods yields results consistent with experimental findings. Theoretical potential energy surfaces predict the occurrence of proton transfer in S{sub 1}-state. Geometrical and energetic criteria, Atoms-In-Molecule topological parameters, Natural Bond Orbital population analysis have been exploited to evaluate the intramolecular hydrogen bond (IMHB) interaction and to explore its directional nature. The inter-correlation between aromaticity and resonance assisted H-bond is also discussed in this context. Our results unveil that the quantum chemical treatment is a more accurate tool to assess hydrogen bonding interaction in comparison to geometrical criteria.

  18. Cone Beam Computed Tomography Evaluation of the Diagnosis, Treatment Planning, and Long-Term Followup of Large Periapical Lesions Treated by Endodontic Surgery: Two Case Reports

    Directory of Open Access Journals (Sweden)

    Vijay Shekhar

    2013-01-01

    Full Text Available The aim of this case report is to present two cases where cone beam computed tomography (CBCT was used for the diagnosis, treatment planning, and followup of large periapical lesions in relation to maxillary anterior teeth treated by endodontic surgery. Periapical disease may be detected sooner using CBCT, and their true size, extent, nature, and position can be assessed. It allows clinician to select the most relevant views of the area of interest resulting in improved detection of periapical lesions. CBCT scan may provide a better, more accurate, and faster method to differentially diagnose a solid (granuloma from a fluid-filled lesion or cavity (cyst. In the present case report, endodontic treatment was performed for both the cases followed by endodontic surgery. Biopsy was done to establish the confirmatory histopathological diagnosis of the periapical lesions. Long-term assessment of the periapical healing following surgery was done in all the three dimensions using CBCT and was found to be more accurate than IOPA radiography. It was concluded that CBCT was a useful modality in making the diagnosis and treatment plan and assessing the outcome of endodontic surgery for large periapical lesions.

  19. Cone Beam Computed Tomography Evaluation of the Diagnosis, Treatment Planning, and Long-Term Followup of Large Periapical Lesions Treated by Endodontic Surgery: Two Case Reports

    Science.gov (United States)

    Shekhar, Vijay; Shashikala, K.

    2013-01-01

    The aim of this case report is to present two cases where cone beam computed tomography (CBCT) was used for the diagnosis, treatment planning, and followup of large periapical lesions in relation to maxillary anterior teeth treated by endodontic surgery. Periapical disease may be detected sooner using CBCT, and their true size, extent, nature, and position can be assessed. It allows clinician to select the most relevant views of the area of interest resulting in improved detection of periapical lesions. CBCT scan may provide a better, more accurate, and faster method to differentially diagnose a solid (granuloma) from a fluid-filled lesion or cavity (cyst). In the present case report, endodontic treatment was performed for both the cases followed by endodontic surgery. Biopsy was done to establish the confirmatory histopathological diagnosis of the periapical lesions. Long-term assessment of the periapical healing following surgery was done in all the three dimensions using CBCT and was found to be more accurate than IOPA radiography. It was concluded that CBCT was a useful modality in making the diagnosis and treatment plan and assessing the outcome of endodontic surgery for large periapical lesions. PMID:23762646

  20. Computational Psychiatry

    Science.gov (United States)

    Wang, Xiao-Jing; Krystal, John H.

    2014-01-01

    Psychiatric disorders such as autism and schizophrenia arise from abnormalities in brain systems that underlie cognitive, emotional and social functions. The brain is enormously complex and its abundant feedback loops on multiple scales preclude intuitive explication of circuit functions. In close interplay with experiments, theory and computational modeling are essential for understanding how, precisely, neural circuits generate flexible behaviors and their impairments give rise to psychiatric symptoms. This Perspective highlights recent progress in applying computational neuroscience to the study of mental disorders. We outline basic approaches, including identification of core deficits that cut across disease categories, biologically-realistic modeling bridging cellular and synaptic mechanisms with behavior, model-aided diagnosis. The need for new research strategies in psychiatry is urgent. Computational psychiatry potentially provides powerful tools for elucidating pathophysiology that may inform both diagnosis and treatment. To achieve this promise will require investment in cross-disciplinary training and research in this nascent field. PMID:25442941

  1. [Computer modelling of electroconvulsive treatment and transcranial magnetic stimulation--an explanation of poor efficacy of the magnetic method].

    Science.gov (United States)

    Zyss, Tomasz; Krawczyk, Andrzej; Zieba, Andrzej; Dudek, Dominika; Hese, Robert T; Drzymała, Paweł; Wiak, Sławomir; Sawicki, Bartosz; Starzyński, Jacek; Szmurło, Robert; Wincenciak, Stanisław

    2010-01-01

    With help of informatics technology it is possible to simulate various physiological processes in virtual models of biological structures. In a created realistic model of the human head we made some comparative investigations over physical phenomena accompanying the electroconvulsive treatment ECT and transcranial magnetic stimulation TMS--two methods with confirmed (ECT) or presumable (TMS) antidepressant efficacy. The present investigations are a continuation of the earlier conducted study in the simple spherical model of the head. Investigations confirmed, that magnetic stimulation TMS generates a considerably weaker current flow in the brain than it is present in electroconvulsive technique. Applying of such weak stimulation in modus,,at haphazard", i.e. on the brain area which does not need to be metabolically disturbed in this patient--cannot cause an antidepressant effect at all. The results of the investigations explain not only the safety of the magnetic method, but the weak effectiveness of this method. The authors propose some methods for improvement of TMS efficacy.

  2. Using animated computer-generated text and graphics to depict the risks and benefits of medical treatment.

    Science.gov (United States)

    Tait, Alan R; Voepel-Lewis, Terri; Brennan-Martinez, Colleen; McGonegal, Maureen; Levine, Robert

    2012-11-01

    Conventional print materials for presenting risks and benefits of treatment are often difficult to understand. This study was undertaken to evaluate and compare subjects' understanding and perceptions of risks and benefits presented using animated computerized text and graphics. Adult subjects were randomized to receive identical risk/benefit information regarding taking statins that was presented on an iPad (Apple Corp, Cupertino, Calif) in 1 of 4 different animated formats: text/numbers, pie chart, bar graph, and pictograph. Subjects completed a questionnaire regarding their preferences and perceptions of the message delivery together with their understanding of the information. Health literacy, numeracy, and need for cognition were measured using validated instruments. There were no differences in subject understanding based on the different formats. However, significantly more subjects preferred graphs (82.5%) compared with text (17.5%, Pbenefits offer an effective means to describe medical risk/benefit statistics. That understanding and satisfaction were significantly better when the format matched the individual's preference for message delivery is important and reinforces the value of "tailoring" information to the individual's needs and preferences. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Evaluation of Strain Distribution in Bone around Implant in Treatment Design of Overdentures Using Computer and Modeling of Finite Elements

    Directory of Open Access Journals (Sweden)

    Masoumeh Khoshhal

    2016-03-01

    Full Text Available Introduction: Introduction: Few studies have investigated the distribution of stress around implants. In this study the distribution of stress in bones around implants was investigated in five overdenture (OD treatment designs including OD-1, OD-2, OD-3, OD-4 and OD-5. Materials and methods: The Catia modeling software was used in order to simulate the tooth/implant model and bone. First, the borders of cancellous and cortical bone in each section of the CT images were attained by Photoshop software. Then, modeling softwares SolidWorks and NUMBER were applied to make the final three-dimensional model of jaw. Finally, the amount of stress on the surface of bone/implant was studied by means of stress analysis software (Ansys v11.0. Results: Protrusive movements of implants B and D in OD-1 showed the highest amount of strain, 2435 εµ. Also, high amounts of strain, 1668 and 1557 εµwere observed in OD-1 and OD-2 designs in lateral movements respectively. Conclusion: The bottom line is that no forces to the extent of destruction based on the Ferost model were found for these designs. The highest amount of strain occurred in OD-1 design, which is held in mild overload window. Moreover, the amounts of strain in the rest of designs investigated were in adaptive window.

  4. Evaluation of Strain Distribution in Bone around Implant in Treatment Design of Overdentures Using Computer and Modeling of Finite Elements

    Directory of Open Access Journals (Sweden)

    Masoumeh Khoshhal

    2015-12-01

    Full Text Available Introduction: Introduction: Few studies have investigated the distribution of stress around implants. In this study the distribution of stress in bones around implants was investigated in five overdenture (OD treatment designs including OD-1, OD-2, OD-3, OD-4 and OD-5. Materials and methods: The Catia modeling software was used in order to simulate the tooth/implant model and bone. First, the borders of cancellous and cortical bone in each section of the CT images were attained by Photoshop software. Then, modeling softwares SolidWorks and NUMBER were applied to make the final three-dimensional model of jaw. Finally, the amount of stress on the surface of bone/implant was studied by means of stress analysis software (Ansys v11.0. Results: Protrusive movements of implants B and D in OD-1 showed the highest amount of strain, 2435 εµ. Also, high amounts of strain, 1668 and 1557 εµwere observed in OD-1 and OD-2 designs in lateral movements respectively. Conclusion: The bottom line is that no forces to the extent of destruction based on the Ferost model were found for these designs. The highest amount of strain occurred in OD-1 design, which is held in mild overload window. Moreover, the amounts of strain in the rest of designs investigated were in adaptive window.

  5. 90Y microsphere (TheraSphere) treatment for unresectable colorectal cancer metastases of the liver: response to treatment at targeted doses of 135-150 Gy as measured by [18F]fluorodeoxyglucose positron emission tomography and computed tomographic imaging.

    Science.gov (United States)

    Lewandowski, Robert J; Thurston, Kenneth G; Goin, James E; Wong, Ching-Yee O; Gates, Vanessa L; Van Buskirk, Mark; Geschwind, Jean-Francois H; Salem, Riad

    2005-12-01

    The purpose of this phase II study was to determine the safety and efficacy of TheraSphere treatment (90Y microspheres) in patients with liver-dominant colorectal metastases in whom standard therapies had failed or were judged to be inappropriate. Twenty-seven patients with unresectable hepatic colorectal metastases were treated at a targeted absorbed dose of 135-150 Gy. Safety and toxicity were assessed according to the National Cancer Institute's Common Toxicity Criteria, version 3.0. Response was assessed with use of computed tomography (CT) and was correlated with response on [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Survival from first treatment was estimated with use of the Kaplan-Meier method. Tumor response measured by FDG PET imaging exceeded that measured by CT imaging for the first (88% vs 35%) and second (73% vs 36%) treated lobes. Tumor replacement of 25% or less (vs >25%) was associated with a statistically significant increase in median survival (339 days vs 162 days; P = .002). Treatment-related toxicities included mild fatigue (n = 13; 48%), nausea (n = 4; 15%), and vague abdominal pain (n = 5; 19%). There was one case of radiation-induced gastritis from inadvertent deposition of microspheres to the gastrointestinal tract (n = 1; 4%). Three patients (11%) experienced ascites/pleural effusion after treatment with TheraSphere as a consequence of liver failure in advanced-stage metastatic disease. With the exception of these three patients whose sequelae were not considered to be related to treatment, all observed toxicities were transient and resolved without medical intervention. TheraSphere administration appears to provide stabilization of liver disease with minimal toxicity in patients in whom standard systemic chemotherapy regimens have failed.

  6. A novel computer system for the evaluation of nasolabial morphology, symmetry and aesthetics after cleft lip and palate treatment. Part 1: General concept and validation.

    Science.gov (United States)

    Pietruski, Piotr; Majak, Marcin; Debski, Tomasz; Antoszewski, Boguslaw

    2017-04-01

    The need for a widely accepted method suitable for a multicentre quantitative evaluation of facial aesthetics after surgical treatment of cleft lip and palate (CLP) has been emphasized for years. The aim of this study was to validate a novel computer system 'Analyse It Doc' (A.I.D.) as a tool for objective anthropometric analysis of the nasolabial region. An indirect anthropometric analysis of facial photographs was conducted with the A.I.D. system and Adobe Photoshop/ImageJ software. Intra-rater and inter-rater reliability and the time required for the analysis were estimated separately for each method and compared. Analysis with A.I.D. system was nearly 10-fold faster than that with the reference evaluation method. The A.I.D. system provided strong inter-rater and intra-rater correlations for linear, angular and area measurements of the nasolabial region, as well as a significantly higher accuracy and reproducibility of angular measurements in submental view. No statistically significant inter-method differences were found for other measurements. The hereby presented novel computer system is suitable for simple, time-efficient and reliable multicenter photogrammetric analyses of the nasolabial region in CLP patients and healthy subjects. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  7. A computer program for monitoring the biological treatment of waste waters (CDBAR); Programa informatico para el control de la depuracion biologica de aguas residuales (CDBAR)

    Energy Technology Data Exchange (ETDEWEB)

    Bove Porta, J.; Milan Cabre, D.

    2001-07-01

    The problems, such as bulking, foaming, etc., involved in managing a waste water treatment plant (WWTP) employing an activated sludge biological process have a biochemical origin. Correcting them requires identifying the micro-organisms responsible for the pathology in question, whether the problems are due to there being too many or too few of these organisms. It is therefore necessary to have a good microscope and staff trained in identifying such micro-organisms. Never the less, to attain speed and efficiency, it is necessary to have more means. That is why the CDBAR project was carried out. This is a simple computer application that includes numerous photographs of microscopic organisms from samples taken in Spain and Portugal. Once the anomaly has been identified, the computer application it-self includes a program of corrective actions that will allow the biological reactor, the most important part of a WWTP, to function normally. Finally, a glossary has been prepared so that the meaning of any term can be looked up quickly and easily. (Author) 16 refs.

  8. Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study.

    Science.gov (United States)

    Rossol, Melanie; Gygax, Diego; Andritzky-Waas, Juliane; Zheng, Guoyan; Lischer, Christoph J; Zhang, Xuan; Auer, Joerg A

    2008-01-01

    To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction. Experimental study. Cadaveric equine limbs (n=32). In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS. In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion. For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique. Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.

  9. Evaluation of orthodontically induced external root resorption following orthodontic treatment using cone beam computed tomography (CBCT): a systematic review and meta-analysis.

    Science.gov (United States)

    Samandara, Aikaterini; Papageorgiou, Spyridon N; Ioannidou-Marathiotou, Ioulia; Kavvadia-Tsatala, Smaragda; Papadopoulos, Moschos A

    2018-05-15

    Orthodontically induced external root resorption (OIRR) is a pathologic consequence of orthodontic tooth movement. However, the limitations of two-dimensional radiography suggest that cone beam computed tomography (CBCT) with its three-dimensional capabilities might be more suitable to assess OIRR. The aim of this study was to assess in an evidence-based manner data on linear or volumetric OIRR measurements of permanent teeth by means of CBCT, during and/or after the end of orthodontic treatment. Unrestricted electronic and hand searches were performed up to January 2017 in 15 databases. Randomized clinical trials, prospective, and retrospective non-randomized studies assessing OIRR during and/or after orthodontic treatment using CBCT in human patients were included. After duplicate study selection, data extraction, and risk-of-bias assessment according to the Cochrane guidelines, random-effects meta-analyses, followed by subgroup, meta-regression, and sensitivity analyses were also performed in order to evaluate factors that affect OIRR. A total of 33 studies (30 datasets) were included in the qualitative analysis while data from 27 of them were included in the quantitative analysis. Direct comparisons from randomized trials found little to no influence of appliance-related factors on OIRR. Explorative analyses including non-randomized studies found a pooled OIRR of 0.79 mm based on all included studies and 0.86 mm when OIRR was assessed at the end of orthodontic treatment. Statistically significant differences in OIRR were found according to tooth type or jaw, inclusion of extractions, treatment duration, and diagnostic accuracy of the CBCT. Based on the results of this study, CBCT seems to be a reliable tool to examine OIRR during or at the end of orthodontic treatment. Although the average OIRR measured with CBCT seems to lack clinical relevance, there are certain factors that may affect OIRR following orthodontic treatment. Nevertheless, due to data

  10. Morphologic and Metabolic Comparison of Treatment Responsiveness with 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography According to Lung Cancer Type

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Börksüz

    2016-06-01

    Full Text Available Objective: The aim of the present study was to evaluate the response to treatment by histopathologic type in patients with lung cancer and under follow-up with 18F-fluoro-2deoxy-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT imaging by using Response Evaluation Criteria in Solid Tumors (RECIST and European Organisation for Research and Treatment of Cancer (EORTC criteria that evaluate morphologic and metabolic parameters. Methods: On two separate (pre- and post-treatment 18F-FDG PET/CT images, the longest dimension of primary tumor as well as of secondary lesions were measured and sum of these two measurements was recorded as the total dimension in 40 patients. PET parameters such as standardized uptake value (SUVmax, metabolic volume and total lesion glycolysis (TLG were also recorded for these target lesions on two separate 18F-FDG PET/CT images. The percent (% change was calculated for all these parameters. Morphologic evaluation was based on RECIST 1.1 and the metabolic evaluation was based on EORTC. Results: When evaluated before and after treatment, in spite of the statistically significant change (p0.05. In histopathologic typing, when we compare the post-treatment phase change with the treatment responses of RECIST 1.1 and EORTC criteria; for RECIST 1.1 in squamous cell lung cancer group, progression was observed in sixteen patients (57%, stability in seven patients (25%, partial response in five patients (18%; and for EORTC progression was detected in four patients (14%, stability in thirteen patients (47%, partial response in eleven patients (39%, in 12 of these patients an increase in stage (43%, in 4 of them a decrease in stage (14%, and in 12 of them stability in stage (43% were determined. But in adenocancer patients (n=7, for RECIST 1.1, progression was determined in four patients (57%, stability in two patients (29%, partial response in one patient (14%; for EORTC, progression in one patient (14

  11. The role of computed tomography in the diagnosis and treatment of malignant tumors of the nasal cavity, paranasal sinuses and nasopharynx

    International Nuclear Information System (INIS)

    Kondo, Makoto; Yamashita, Shoji; Inuyama, Yukio; Shiga, Hayao; Hashimoto, Shozo

    1986-01-01

    We studied the value of computed tomography (CT) in diagnosis and treatment of primary malignant tumors of the sinonasal cavities and nasopharynx, and reached the following conclusions. 1) In maxillary carcinomas, bone destruction is always seen on CT. When bone destruction is not apparent despite invasion to the adjacent site, malignant lymphoma or plasmacytoma is suggested. 2) In defining the tumor extent of maxillary SCC, CT is more reliable than maxillotomy, and is equal to maxillectomy. However, clouding of the sinus without bone destruction remains a problem, since this finding can be caused by either tumor invasion or obstructive sinusitis. 3) In maxillary and nasopharyngeal SCC, CT frequently reveals tumors to be more extensive than previously suspected following physical and conventional x-ray examinations. Therefore, the T-stages of these tumors are often upstaged to more advanced ones. 4) CT is of great help in identifying candidates for surgery in maxillary SCC, and in planning radiation therapy for nasopharyngeal and sinonasal tumors. Dose distribution curves displayed directly on the CT slices are becoming essential tools for radiation oncologists. After the introduction of CT, treatment results in cases of nasopharyngeal SCC have improved, probably due to better definition of the tumor volumes. 5) CT is also used for observing tumor response after therapy and for follow-up. In summary, CT is now indispensable in the management of malignant tumors of these sites. (author)

  12. Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

    International Nuclear Information System (INIS)

    Maksimovic, Ruzica; Cademartiri, Filippo; Pattynama, Peter M.T.; Scholten, Marcoen F.; Jordaens, Luc J.

    2005-01-01

    The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1±2.4 preprocedural versus 18.6±2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2±0.2 versus 1.2±0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1±2.5 mm versus 16.5±2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up. (orig.)

  13. Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, Ruzica; Cademartiri, Filippo; Pattynama, Peter M.T. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Scholten, Marcoen F.; Jordaens, Luc J. [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands)

    2005-06-01

    The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1{+-}2.4 preprocedural versus 18.6{+-}2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2{+-}0.2 versus 1.2{+-}0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1{+-}2.5 mm versus 16.5{+-}2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up. (orig.)

  14. Sixteen-row multislice computed tomography in the assessment of pulmonary veins prior to ablative treatment: validation vs conventional pulmonary venography and study of reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, R.; Cademartiri, F.; Pattynama, P.M.T. [Erasmus Medical Center, Rotterdam (Netherlands). Dept. of Radiology; Scholten, M; Jordaens, L.J. [Erasmus Medical Center, Rotterdam (Netherlands). Dept. of Cardiology

    2004-03-01

    The aim of this study was to validate multislice computed tomography (MSCT) venography measurements of pulmonary vein (PV) diameters vs conventional pulmonary venography (CPV), and to assess the reproducibility of MSCT data. The study included 21 consecutive patients with atrial fibrillation who were planned for cryothermal ablation of PVs. One day before ablation, all patients underwent CPV and contrast-enhanced non-gated MSCT venography. The MSCT was repeated 3 months after ablation. The CPV images of the treated PVs (n=40) were analyzed and compared with the results of MSCT measurements. Reproducibility of MSCT venography-based data was assessed by interobserver (n=84 PVs) and interexamination (n=44 PVs) variability. Pre-treatment PV diameters on MSCT and CPV showed good correlation (r=0.87, p<0.01; 18.9{+-}2.3 mm, 188.5{+-}2.4 mm, respectively). Interobserver agreement and interexamination reproducibility were good (r=0.91, r=0.82, respectively, p<0.01), with narrow limits of agreement (Bland and Altman method). The MSCT venography allows accurate and reproducible assessment of PVs. It can be used both in non-invasive planning of treatment for ablative therapy and in the follow-up of patients.

  15. Influence of Distal Resistance and Proximal Stiffness on Hemodynamics and RV Afterload in Progression and Treatments of Pulmonary Hypertension: A Computational Study with Validation Using Animal Models

    Directory of Open Access Journals (Sweden)

    Zhenbi Su

    2013-01-01

    Full Text Available We develop a simple computational model based on measurements from a hypoxic neonatal calf model of pulmonary hypertension (PH to investigate the interplay between vascular and ventricular measures in the setting of progressive PH. Model parameters were obtained directly from in vivo and ex vivo measurements of neonatal calves. Seventeen sets of model-predicted impedance and mean pulmonary arterial pressure (mPAP show good agreement with the animal measurements, thereby validating the model. Next, we considered a predictive model in which three parameters, PVR, elastic modulus (EM, and arterial thickness, were varied singly from one simulation to the next to study their individual roles in PH progression. Finally, we used the model to predict the individual impacts of clinical (vasodilatory and theoretical (compliance increasing PH treatments on improving pulmonary hemodynamics. Our model (1 displayed excellent patient-specific agreement with measured global pulmonary parameters; (2 quantified relationships between PVR and mean pressure and PVS and pulse pressure, as well as studiying the right ventricular (RV afterload, which could be measured as a hydraulic load calculated from spectral analysis of pulmonary artery pressure and flow waves; (3 qualitatively confirmed the derangement of vascular wall shear stress in progressive PH; and (4 established that decreasing proximal vascular stiffness through a theoretical treatment of reversing proximal vascular remodeling could decrease RV afterload.

  16. Efficacy of platelet-rich fibrin vs. enamel matrix derivative in the treatment of periodontal intrabony defects: a clinical and cone beam computed tomography study.

    Science.gov (United States)

    Gupta, Swyeta Jain; Jhingran, Rajesh; Gupta, Vivek; Bains, Vivek Kumar; Madan, Rohit; Rizvi, Iram

    2014-07-01

    To evaluate and compare the efficacy of platelet-rich fibrin (PRF) with enamel matrix derivative (EMD; Emdogain) in the treatment of periodontal intrabony defects in patients with chronic periodontitis, six months after surgery. Forty-four (44) intrabony defects in 30 patients (15 males) were randomly allocated into two treatment groups: EMD (n = 22) and PRF (n = 22). Measurement of the defects was done using clinical and cone beam computed tomography at baseline and 6 months. Clinical and radiographic parameters such as probing depth, clinical attachment level, intrabony defect depth and defect angle, were recorded at baseline and 6 months post-operatively. Within group change was evaluated using the Wilcoxon signed rank test. Intergroup comparisons were made using the Mann-Whitney U test. Postsurgical measurements revealed that there was an equal reduction in probing depth and a greater but statistically non-significant attachment gain for the Emdogain group when compared to the platelet-rich fibrin group. The Emdogain group presented with significantly greater percentage defect resolution (43.07% ± 12.21) than did the platelet-rich fibrin group (32.41% ± 14.61). Post-operatively the changes in defect width and defect angle were significant in both groups, but upon intergroup comparison they were found to be statistically non-significantly different. Both Emdogain and platelet-rich fibrin were effective in the regeneration of intrabony defects. Emdogain was significantly superior in terms of percentage defect resolution.

  17. Evaluation of Effective Parameters on Quality of Magnetic Resonance Imaging-computed Tomography Image Fusion in Head and Neck Tumors for Application in Treatment Planning

    Directory of Open Access Journals (Sweden)

    Atefeh Shirvani

    2017-01-01

    Full Text Available Background: In radiation therapy, computed tomography (CT simulation is used for treatment planning to define the location of tumor. Magnetic resonance imaging (MRI-CT image fusion leads to more efficient tumor contouring. This work tried to identify the practical issues for the combination of CT and MRI images in real clinical cases. The effect of various factors is evaluated on image fusion quality. Materials and Methods: In this study, the data of thirty patients with brain tumors were used for image fusion. The effect of several parameters on possibility and quality of image fusion was evaluated. These parameters include angles of the patient's head on the bed, slices thickness, slice gap, and height of the patient's head. Results: According to the results, the first dominating factor on quality of image fusion was the difference slice gap between CT and MRI images (cor = 0.86, P 4 cm and image fusion quality was <25%. Conclusion: The most important problem in image fusion is that MRI images are taken without regard to their use in treatment planning. In general, parameters related to the patient position during MRI imaging should be chosen to be consistent with CT images of the patient in terms of location and angle.

  18. A study on planning organ at risk volume for the rectum using cone beam computed tomography in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Prabhakar, Ramachandran; Oates, Richard; Jones, Daryl; Kron, Tomas; Cramb, Jim; Foroudi, Farshad; Geso, Moshi; Gill, Suki

    2014-01-01

    In this study, we analyzed planning organ at risk volume (PRV) for the rectum using a series of cone beam computed tomographies (CBCTs) acquired during the treatment of prostate cancer and evaluated the dosimetric effect of different PRV definitions. Overall, 21 patients with prostate cancer were treated radically with 78 Gy in 39 fractions had in total 418 CBCTs, each acquired at the end of the first 5 fractions and then every alternate fraction. The PRV was generated from the Boolean sum volume of the rectum obtained from first 5 fractions (PRV-CBCT-5) and from all CBCTs (PRV-CBCT-All). The PRV margin was compared at the superior, middle, and inferior slices of the contoured rectum to compare PRV-CBCT-5 and PRV-CBCT-All. We also compared the dose received by the planned rectum (Rectum-computed tomography [CT]), PRV-CBCT-5, PRV-CBCT-All, and average rectum (CBCT-AV-dose-volume histogram [DVH]) at critical dose levels. The average measured rectal volume for all 21 patients for Rectum-CT, PRV-CBCT-5, and PRV-CBCT-All was 44.3 ± 15.0, 92.8 ± 40.40, and 121.5 ± 36.7 cm 3 , respectively. For PRV-CBCT-All, the mean ± standard deviation displacement in the anterior, posterior, right, and left lateral directions in centimeters was 2.1 ± 1.1, 0.9 ± 0.5, 0.9 ± 0.8, and 1.1 ± 0.7 for the superior rectum; 0.8 ± 0.5, 1.1 ± 0.5, 1.0 ± 0.5, and 1.0 ± 0.5 for the middle rectum; and 0.3 ± 0.3; 0.9 ± 0.5; 0.4 ± 0.2, and 0.5 ± 0.3 for the inferior rectum, respectively. The first 5 CBCTs did not predict the PRV for individual patients. Our study shows that the PRV margin is different for superior, middle, and the inferior parts of the rectum, it is wider superiorly and narrower inferiorly. A uniform PRV margin does not represent the actual rectal variations during treatment for all treatment fractions. The large variation in interpatient rectal size implies a potential role for adaptive radiotherapy for prostate cancer

  19. Conventional four-field pelvic radiotherapy technique without computed tomography-treatment planning in cancer of the cervix: potential geographic miss and its impact on pelvic control

    International Nuclear Information System (INIS)

    Kim, Robert Y.; McGinnis, L. Scott; Spencer, Sharon A.; Meredith, Ruby F.; Jennelle, Richard L.S.; Salter, Merle M.

    1995-01-01

    Purpose: To evaluate the impact of inadequate margins on pelvic control using the conventional four-field pelvic portals without computed tomography (CT)-treatment planning. Methods and Materials: Between 1986 and 1991, 34 patients with invasive cancer of the cervix were eligible for outcome study of conventional four-field radiation therapy (10 Stage I, 16 Stage II, 8 Stage III). The eligibility for this study includes four-field pelvic technique, definitive radiation therapy, and diagnostic CT scan of the pelvis. For this study, an inadequate margin is arbitrarily defined as ≤ 1.0 cm of normal tissue around the CT-defined tumor volume. Results: All 34 patients had adequate margins for anterio-posterior/posterio-anterior portals. However, 19 patients had an inadequate margin at the posterior border (S2-S3 interspace) and/or custom-shaped rectal block for lateral pelvic portals. Two patients had inadequate margins at the anterior border (level of symphysis pubis) due to an enlarged uterus. With a median follow-up of 36 months, pelvic control for adequate margins and inadequate margins was 100% and 71% for Stage IB disease and 88% and 50% for Stage IIB disease, respectively. However, pelvic control for Stage IIIB disease was 50% for both groups. There was no difference in total dose to point A or point B between the two groups. Conclusion: Our preliminary data show higher local failure in patients with an inadequate margin. For four-field pelvic radiation therapy, we strongly recommend CT-treatment planning. Otherwise, anterio-posterior/posterio-anterior pelvic therapy is the most reliable treatment for cancer of the uterine cervix

  20. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Lei Zhen, E-mail: leizhen2004@163.com [Department of Anatomy, Chinese Medical University, No. 92, Beiermalu Road, Heping District, Shenyang, 110001 (China) and Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Ma Heji, E-mail: maheji9831@sina.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xu Na, E-mail: xuna821230@sohu.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xi Huanjiu, E-mail: xihuanjiu2004@yahoo.cn [Anthropology Institute, Liaoning Medical College, No. 40, Sanduan, Songpo Rd, Jinzhou, 121001 (China)

    2011-05-15

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  1. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    International Nuclear Information System (INIS)

    Lei Zhen; Ma Heji; Xu Na; Xi Huanjiu

    2011-01-01

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  2. An update to the HIV-TRePS system: the development of new computational models that do not require a genotype to predict HIV treatment outcomes.

    Science.gov (United States)

    Revell, Andrew D; Wang, Dechao; Wood, Robin; Morrow, Carl; Tempelman, Hugo; Hamers, Raph; Alvarez-Uria, Gerardo; Streinu-Cercel, Adrian; Ene, Luminita; Wensing, Annemarie; Reiss, Peter; van Sighem, Ard I; Nelson, Mark; Emery, Sean; Montaner, Julio S G; Lane, H Clifford; Larder, Brendan A

    2014-04-01

    The optimal individualized selection of antiretroviral drugs in resource-limited settings is challenging because of the limited availability of drugs and genotyping. Here we describe the development of the latest computational models to predict the response to combination antiretroviral therapy without a genotype, for potential use in such settings. Random forest models were trained to predict the probability of a virological response to therapy (HIV RNA/mL) following virological failure using the following data from 22,567 treatment-change episodes including 1090 from southern Africa: baseline viral load and CD4 cell count, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. The models were assessed during cross-validation and with an independent global test set of 1000 cases including 100 from southern Africa. The models' accuracy [area under the receiver-operating characteristic curve (AUC)] was evaluated and compared with genotyping using rules-based interpretation systems for those cases with genotypes available. The models achieved AUCs of 0.79-0.84 (mean 0.82) during cross-validation, 0.80 with the global test set and 0.78 with the southern African subset. The AUCs were significantly lower (0.56-0.57) for genotyping. The models predicted virological response to HIV therapy without a genotype as accurately as previous models that included a genotype. They were accurate for cases from southern Africa and significantly more accurate than genotyping. These models will be accessible via the online treatment support tool HIV-TRePS and have the potential to help optimize antiretroviral therapy in resource-limited settings where genotyping is not generally available.

  3. Cervical lymph node hyperplasia on [18F]-fluorodeoxyglucose positron emission tomography/computed tomography scan after treatment of children and adolescents with malignant lymphoma

    International Nuclear Information System (INIS)

    Hu, Ying-Ying; Zhang, Xu; Long, Wen; Lin, Xiao-Ping; Zhang, Ya-Rui; Li, Yuan-Hua; Xiao, Zi-Zheng; Zheng, Rong-Liang; Liang, Pei-Yan; Fan, Wei

    2015-01-01

    Highlights: • Cervical lymph node hyperplasia is a benign processes. • Lymph node hyperplasia found in treated children and adolescents with lymphoma. • We define imaging manifestations of cervical lymph node hyperplasia in PET/CT. • Awareness of lymph node hyperplasia avoid invasive procedures and over-treatment. - Abstract: Purpose: To define imaging manifestations and clinical prognosis of cervical lymph node hyperplasia using [ 18 F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning after treatment of children and adolescents with malignant lymphoma. Methods: Children and adolescent patients with malignant lymphoma who had high FDG uptake in their cervical lymph nodes via PET/CT after treatment, which was not due to tumor recurrence or residue, were retrospectively analyzed. Results: Twenty-seven patients with a median age of 12 years were included; 11 had Hodgkin's disease and 16 had non-Hodgkin's lymphoma. The time from PET/CT scan to completion of therapy was 1–36 months, 85.2% (23/27) of which took place within 12 months. Three patients had confirmed lymph node follicular hyperplasia by biopsy, while all 27 patients achieved disease-free survival during the follow-up period. The maximum standardized uptake values (SUV max ) of cervical lymph nodes were 2.2–16.2 and the maximum short axis ranged from 0.3 to 1.2 cm. Cervical lymph node hyperplasia was noted in neck levels I–V, and neck level II bilaterally had the highest incidence (100%). Bilateral cervical lymph node hyperplasia was symmetrical in terms of both the SUV max and affected locations. Thymic hyperplasia and nasopharyngeal lymphoid hyperplasia were both observed in 24 patients (88.9%). There was no relationship in terms of the SUV max between cervical lymph nodes and thymic tissue, cervical nodes or nasopharyngeal lymphoid tissue. Conclusion: Cervical lymph node hyperplasia with high FDG uptake on PET/CT scans found after treating

  4. Cervical lymph node hyperplasia on [{sup 18}F]-fluorodeoxyglucose positron emission tomography/computed tomography scan after treatment of children and adolescents with malignant lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ying-Ying, E-mail: huyy@sysucc.org.cn; Zhang, Xu, E-mail: zhangxu2@sysucc.org.cn; Long, Wen, E-mail: longwen2@sysucc.org.cn; Lin, Xiao-Ping, E-mail: linxp@sysucc.org.cn; Zhang, Ya-Rui, E-mail: zhangyr@sysucc.org.cn; Li, Yuan-Hua, E-mail: liyh@sysucc.org.cn; Xiao, Zi-Zheng, E-mail: xiaozzh@sysucc.org.cn; Zheng, Rong-Liang, E-mail: zhengrl@sysucc.org.cn; Liang, Pei-Yan, E-mail: liangpy@sysucc.org.cn; Fan, Wei, E-mail: fanwei@sysucc.org.cn

    2015-07-15

    Highlights: • Cervical lymph node hyperplasia is a benign processes. • Lymph node hyperplasia found in treated children and adolescents with lymphoma. • We define imaging manifestations of cervical lymph node hyperplasia in PET/CT. • Awareness of lymph node hyperplasia avoid invasive procedures and over-treatment. - Abstract: Purpose: To define imaging manifestations and clinical prognosis of cervical lymph node hyperplasia using [{sup 18}F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning after treatment of children and adolescents with malignant lymphoma. Methods: Children and adolescent patients with malignant lymphoma who had high FDG uptake in their cervical lymph nodes via PET/CT after treatment, which was not due to tumor recurrence or residue, were retrospectively analyzed. Results: Twenty-seven patients with a median age of 12 years were included; 11 had Hodgkin's disease and 16 had non-Hodgkin's lymphoma. The time from PET/CT scan to completion of therapy was 1–36 months, 85.2% (23/27) of which took place within 12 months. Three patients had confirmed lymph node follicular hyperplasia by biopsy, while all 27 patients achieved disease-free survival during the follow-up period. The maximum standardized uptake values (SUV{sub max}) of cervical lymph nodes were 2.2–16.2 and the maximum short axis ranged from 0.3 to 1.2 cm. Cervical lymph node hyperplasia was noted in neck levels I–V, and neck level II bilaterally had the highest incidence (100%). Bilateral cervical lymph node hyperplasia was symmetrical in terms of both the SUV{sub max} and affected locations. Thymic hyperplasia and nasopharyngeal lymphoid hyperplasia were both observed in 24 patients (88.9%). There was no relationship in terms of the SUV{sub max} between cervical lymph nodes and thymic tissue, cervical nodes or nasopharyngeal lymphoid tissue. Conclusion: Cervical lymph node hyperplasia with high FDG uptake on PET/CT scans found

  5. SU-E-J-70: Feasibility Study of Dynamic Arc and IMRT Treatment Plans Utilizing Vero Treatment Unit and IPlan Planning Computer for SRS/FSRT Brain Cancer Patients

    International Nuclear Information System (INIS)

    Huh, S; Lee, S; Dagan, R; Malyapa, R; Mendenhall, N; Mendenhall, W; Ho, M; Hough, D; Yam, M; Li, Z

    2014-01-01

    Purpose: To investigate the feasibility of utilizing Dynamic Arc (DA) and IMRT with 5mm MLC leaf of VERO treatment unit for SRS/FSRT brain cancer patients with non-invasive stereotactic treatments. The DA and IMRT plans using the VERO unit (BrainLab Inc, USA) are compared with cone-based planning and proton plans to evaluate their dosimetric advantages. Methods: The Vero treatment has unique features like no rotational or translational movements of the table during treatments, Dynamic Arc/IMRT, tracking of IR markers, limitation of Ring rotation. Accuracies of the image fusions using CBCT, orthogonal x-rays, and CT are evaluated less than ∼ 0.7mm with a custom-made target phantom with 18 hidden targets. 1mm margin is given to GTV to determine PTV for planning constraints considering all the uncertainties of planning computer and mechanical uncertainties of the treatment unit. Also, double-scattering proton plans with 6F to 9F beams and typical clinical parameters, multiple isocenter plans with 6 to 21 isocenters, and DA/IMRT plans are evaluated to investigate the dosimetric advantages of the DA/IMRT for complex shape of targets. Results: 3 Groups of the patients are divided: (1) Group A (complex target shape), CI's are same for IMRT, and DGI of the proton plan are better by 9.5% than that of the IMRT, (2) Group B, CI of the DA plans (1.91+/−0.4) are better than cone-based plan, while DGI of the DA plan is 4.60+/−1.1 is better than cone-based plan (5.32+/−1.4), (3) Group C (small spherical targets), CI of the DA and cone-based plans are almost the same. Conclusion: For small spherical targets, cone-based plans are superior to other 2 plans: DS proton and DA plans. For complex or irregular plans, dynamic and IMRT plans are comparable to cone-based and proton plans for complex targets

  6. Computer modeling of the optical properties and heating of spherical gold and silica-gold nanoparticles for laser combined imaging and photothermal treatment

    International Nuclear Information System (INIS)

    Pustovalov, V; Astafyeva, L; Jean, B

    2009-01-01

    Recently, several groups of investigators (Anderson, Halas, Zharov, El-Sayed and their co-workers (Pitsillides et al 2003 Biophys. J. 84 4023-31, Zharov et al 2003 Appl. Phys. Lett. 83 4897-9, Zharov et al 2004 Proc. SPIE 5319 291-9, Loo et al 2005 Nano Lett. 5 709-11, Gobin et al 2007 Nano Lett. 7 1929-34, Fu et al 2008 Nanotechnology 19 045103, Huang et al 2006 J. Am. Chem. Soc. 128 2115-20, Jain et al 2006 J. Phys. Chem. B 110 7238-48, Jain et al 2007 Nano Today 2 18-29)) demonstrated, through pioneering results, the great potential of laser thermal therapy of cells and tissues conjugated with gold nanoparticles. It was also proposed to use combined diagnostics and therapy on the basis of nanoparticle selection for achievement of efficient contrast for laser imaging applications, as well as for photothermal therapy. However, the current understanding of the relationship between optical properties (absorption, backscattering) of nanoparticles, the efficiency of nanoparticle heating and the possibility to use them for combined imaging and therapy is limited. Here, we report the results of computer modeling of optical absorption and backscattering properties and laser heating of gold and silica-gold spherical nanoparticles for laser combined imaging and photothermal treatment of cells and tissues conjugated with nanoparticles. The efficiencies of nanoparticle heating and backscattering by nanoparticles, depending upon their radii, structure and optical properties of the metal, were investigated. This paper focuses on the analysis and determination of appropriate ranges of nanoparticle sizes for the purposes of laser combined imaging and photothermal treatment. The possibility to use spherical gold and silica-gold nanoparticles in determined ranges of radii for these purposes for laser wavelengths 532 and 800 nm is investigated.

  7. Effect of length and location of edentulous area on the accuracy of prosthetic treatment plan incorporation into cone-beam computed tomography scans.

    Science.gov (United States)

    Jamjoom, Faris Z; Kim, Do-Gyoon; Lee, Damian J; McGlumphy, Edwin A; Yilmaz, Burak

    2018-02-05

    Effects of length and location of the edentulous area on the accuracy of prosthetic treatment plan incorporation into cone-beam computed tomography (CBCT) scans has not been investigated. To evaluate the effect of length and location of the edentulous area on the accuracy of prosthetic treatment plan incorporation into CBCT scans using different methods. Direct digital scans of a completely dentate master model with removable radiopaque teeth were made using an intraoral scanner, and digital scans of stone duplicates of the master model were made using a laboratory scanner. Specific teeth were removed to simulate different clinical situations and their CBCT scans were made. Surface scans were registered onto the CBCT scans. Radiographic templates for each clinical situation were also fabricated and used during CBCT scans of the master models. Using metrology software, three-dimensional (3D) deviation was measured on standard tesselation language (STL) files created from the CBCT scans against an STL file of the master model created from a CBCT scan. Statistical analysis was done using the MIXED procedure in a statistical software and Tukey HSD test (α =.05). The interaction between location and method was significant (P = .009). Location had no significant effect on registration methods (P > .05), but on the radiographic templates (P = .011). Length of the edentulous area did not have any significant effect (P > .05). Accuracy of digital image registration methods was similar and higher than that of radiographic templates in all clinical situations. Tooth-bound radiographic templates were significantly more accurate than the free-end templates. The results of this study suggest using image registration instead of radiographic templates when planning dental implants, particularly in free-end situations. © 2018 Wiley Periodicals, Inc.

  8. A Computational Framework for Planning Therapeutical Sessions aimed to Support the Prevention and Treatment of Mental Health Disorders using Emotional Virtual Agents

    OpenAIRE

    BRESÓ GUARDADO, ADRIÁN

    2016-01-01

    [EN] Interaction is defined as the realization of a reciprocal action between two or more people or things. Particularly in computer science, the term interaction refers to the discipline that studies the exchange of information between people and computers, and is generally known by the term Human-Computer Interaction (HCI). Good design decisions and an adequate development of the software is required for efficient HCI to facilitate the acceptability of computer-based applications by the...

  9. X-ray computed microtomography analysis of the influence of different agricultural treatments on the topsoil porosity of a Grey Brown Luvisol from Ontario

    Science.gov (United States)

    Taina, I. A.; Heck, R. J.; Scaiff, N. T.

    2009-05-01

    One of the most important applications of X-ray computed tomography (CT) for the study of soil is the characterization of the shape and spatial distribution of pores. Analysis of 3D X-ray CT image data, related to different pore categories, can provide insight to soil structural changes, which have implications in water infiltration and soil aeration, resulting from agricultural practices. The aim of this study was to evaluate changes in the spatial characteristics of voids, due to tillage practices, in the Ap horizon of an Orthic Grey- Brown Luvisol (located at the Elora Research Station of the University of Guelph). Undisturbed oriented soil samples were collected from ten plots representing different tillage treatments: spring moldboard plow, spring moldboard plow, cultivate and pack, fall moldboard plow, cultivate and pack, spring tandem disc, no cultivator, fall offset disc, fall offset disc, cultivate and pack, fall chisel plow, cultivate and pack, zero zone till (soys twin rows), zero tillage (long term), and zero tillage (corn residue removed in row, soys twin rows). Since the utilization of standardized classes, in the quantification of similar features, proved to be necessary in order to obtain comparable results, categories of pores, separated according to their size, circularity and orientation were considered in the interpretation of data. Total volume of pores and volume percentage of each class were calculated, revealing substantial differences among the analyzed soil samples.

  10. Computed tomography of the brain following prophylactic treatment with irradiation therapy and intraspinal metho-trexate in children with acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Lund, E.; Hamborg-Pedersen, B.

    1984-01-01

    In 28 children with acute lymphoblastic leukemia (ALL) computed tomography (CT) was performed in order to demonstrate possible cerebral changes following treatment with prophylactic irradiation and intraspinal methotrexate (MTX). The time of CT-scan examination varied from 1 year and 1 month to 10 years and 1 month after diagnosis of ALL. The age of the children ranged from 3 years and 11 months to 14 years and 5 months. Six children had normal CT scans, 12 children had slight atrophylike changes, and nine had severe cerebral atrophy. Two patients in the latter group presented an enlarged ventricular system as well. In one patient intracerebral calcification was the only pathologic finding. The severe changes were seen in children of all age groups, but predominantly-in children with a short duration of their disease, severe symptoms, and frequent marrow relapse. Changes induced by steroid therapy may be reversible. No satisfactory explanation of the demonstrated cerebral pathologic findings can be given, except that they are the consequences of the combination of total therapy and severity of disease in the individual patient. Measurement of attenuation coefficients in grey and white matter shows increasing values with age during childhood. A combination of decreasing attenuation coefficients, especially in the white matter, and the finding of severe atrophy seems to be a bad prognostic sign. (orig.)

  11. Comparison of Contrast-Enhanced Ultrasound and Computed Tomography in Classifying Endoleaks After Endovascular Treatment of Abdominal Aorta Aneurysms: Preliminary Experience

    International Nuclear Information System (INIS)

    Carrafiello, Gianpaolo; Lagana, Domenico; Recaldini, Chiara; Mangini, Monica; Bertolotti, Elena; Caronno, Roberto; Tozzi, Matteo; Piffaretti, Gabriele; Annibale Genovese, Eugenio; Fugazzola, Carlo

    2006-01-01

    The purpose of the study was to assess the effectiveness of contrast-enhanced ultrasonography (CEUS) in endoleak classification after endovascular treatment of an abdominal aortic aneurysm compared to computed tomography angiography (CTA). From May 2001 to April 2003, 10 patients with endoleaks already detected by CTA underwent CEUS with Sonovue (registered) to confirm the CTA classification or to reclassify the endoleak. In three conflicting cases, the patients were also studied with conventional angiography. CEUS confirmed the CTA classification in seven cases (type II endoleaks). Two CTA type III endoleaks were classified as type II using CEUS and one CTA type II endoleak was classified as type I by CEUS. Regarding the cases with discordant classification, conventional angiography confirmed the ultrasound classification. Additionally, CEUS documented the origin of type II endoleaks in all cases. After CEUS reclassification of endoleaks, a significant change in patient management occurred in three cases. CEUS allows a better attribution of the origin of the endoleak, as it shows the flow in real time. CEUS is more specific than CTA in endoleak classification and gives more accurate information in therapeutic planning

  12. Quantum computing

    International Nuclear Information System (INIS)

    Steane, Andrew

    1998-01-01

    The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This review aims to summarize not just quantum computing, but the whole subject of quantum information theory. Information can be identified as the most general thing which must propagate from a cause to an effect. It therefore has a fundamentally important role in the science of physics. However, the mathematical treatment of information, especially information processing, is quite recent, dating from the mid-20th century. This has meant that the full significance of information as a basic concept in physics is only now being discovered. This is especially true in quantum mechanics. The theory of quantum information and computing puts this significance on a firm footing, and has led to some profound and exciting new insights into the natural world. Among these are the use of quantum states to permit the secure transmission of classical information (quantum cryptography), the use of quantum entanglement to permit reliable transmission of quantum states (teleportation), the possibility of preserving quantum coherence in the presence of irreversible noise processes (quantum error correction), and the use of controlled quantum evolution for efficient computation (quantum computation). The common theme of all these insights is the use of quantum entanglement as a computational resource. It turns out that information theory and quantum mechanics fit together very well. In order to explain their relationship, this review begins with an introduction to classical information theory and computer science, including Shannon's theorem, error correcting codes, Turing machines and computational complexity. The principles of quantum mechanics are then outlined, and the Einstein, Podolsky and Rosen (EPR) experiment described. The EPR-Bell correlations, and quantum entanglement in general, form the essential new ingredient which distinguishes quantum from

  13. Quantum computing

    Energy Technology Data Exchange (ETDEWEB)

    Steane, Andrew [Department of Atomic and Laser Physics, University of Oxford, Clarendon Laboratory, Oxford (United Kingdom)

    1998-02-01

    The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This review aims to summarize not just quantum computing, but the whole subject of quantum information theory. Information can be identified as the most general thing which must propagate from a cause to an effect. It therefore has a fundamentally important role in the science of physics. However, the mathematical treatment of information, especially information processing, is quite recent, dating from the mid-20th century. This has meant that the full significance of information as a basic concept in physics is only now being discovered. This is especially true in quantum mechanics. The theory of quantum information and computing puts this significance on a firm footing, and has led to some profound and exciting new insights into the natural world. Among these are the use of quantum states to permit the secure transmission of classical information (quantum cryptography), the use of quantum entanglement to permit reliable transmission of quantum states (teleportation), the possibility of preserving quantum coherence in the presence of irreversible noise processes (quantum error correction), and the use of controlled quantum evolution for efficient computation (quantum computation). The common theme of all these insights is the use of quantum entanglement as a computational resource. It turns out that information theory and quantum mechanics fit together very well. In order to explain their relationship, this review begins with an introduction to classical information theory and computer science, including Shannon's theorem, error correcting codes, Turing machines and computational complexity. The principles of quantum mechanics are then outlined, and the Einstein, Podolsky and Rosen (EPR) experiment described. The EPR-Bell correlations, and quantum entanglement in general, form the essential new ingredient which distinguishes quantum from

  14. Treatment Effect of Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension Quantified by Automatic Comparative Imaging in Computed Tomography Pulmonary Angiography.

    Science.gov (United States)

    Zhai, Zhiwei; Ota, Hideki; Staring, Marius; Stolk, Jan; Sugimura, Koichiro; Takase, Kei; Stoel, Berend C

    2018-05-01

    Balloon pulmonary angioplasty (BPA) in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) can have variable outcomes. To gain more insight into this variation, we designed a method for visualizing and quantifying changes in pulmonary perfusion by automatically comparing computed tomography (CT) pulmonary angiography before and after BPA treatment. We validated these quantifications of perfusion changes against hemodynamic changes measured with right-sided heart catheterization. We studied 14 consecutive CTEPH patients (12 women; age, 70.5 ± 24), who underwent CT pulmonary angiography and right-sided heart catheterization, before and after BPA. Posttreatment images were registered to pretreatment CT scans (using the Elastix toolbox) to obtain corresponding locations. Pulmonary vascular trees and their centerlines were detected using a graph cuts method and a distance transform method, respectively. Areas distal from vessels were defined as pulmonary parenchyma. Subsequently, the density changes within the vascular centerlines and parenchymal areas were calculated and corrected for inspiration level differences. For visualization, the densitometric changes were displayed in color-coded overlays. For quantification, the median and interquartile range of the density changes in the vascular and parenchymal areas (ΔVD and ΔPD) were calculated. The recorded changes in hemodynamic parameters, including changes in systolic, diastolic, and mean pulmonary artery pressure (ΔsPAP, ΔdPAP, and ΔmPAP, respectively) and vascular resistance (ΔPVR), were used as reference assessments of the treatment effect. Spearman correlation coefficients were employed to investigate the correlations between changes in perfusion and hemodynamic changes. Comparative imaging maps showed distinct patterns in perfusion changes among patients. Within pulmonary vessels, the interquartile range of ΔVD correlated significantly with ΔsPAP (R = -0.58, P = 0.03),

  15. Magnetic resonance imaging in the radiation treatment planning of localized prostate cancer using intra-prostatic fiducial markers for computed tomography co-registration

    International Nuclear Information System (INIS)

    Parker, C.C.; Damyanovich, A.; Haycocks, T.; Haider, M.; Bayley, A.; Catton, C.N.

    2003-01-01

    Purpose: To assess the feasibility, and potential implications, of using intra-prostatic fiducial markers, rather than bony landmarks, for the co-registration of computed tomography (CT) and magnetic resonance (MR) images in the radiation treatment planning of localized prostate cancer. Methods: All men treated with conformal therapy for localized prostate cancer underwent routine pre-treatment insertion of prostatic fiducial markers to assist with gross target volume (GTV) delineation and to identify prostate positioning during therapy. Six of these men were selected for investigation. Phantom MRI measurements were obtained to quantify image distortion, to determine the most suitable gold alloy marker composition, and to identify the spin-echo sequences that optimized both marker identification and the contrast between the prostate and the surrounding tissues. The GTV for each patient was contoured independently by three radiation oncologists on axial planning CT slices, and on axial MRI slices fused to the CT slices by matching the implanted fiducial markers. From each set of contours the scan common volume (SCV), and the scan encompassing volume (SEV), were obtained. The ratio SEV/SCV for a given scan is a measure of inter-observer variation in contouring. For each of the 18 patient-observer combinations the observer common volume (OCV) and the observer encompassing volume (OEV) was obtained. The ratio OEV/OCV for a given patient-observer combination is a measure of the inter-modality variation in contouring. The distance from the treatment planning isocenter to the prostate contours was measured and the discrepancy between the CT- and the MR-defined contour recorded. The discrepancies between the CT- and MR-defined contours of the posterior prostate were recorded in the sagittal plane at 1-cm intervals above and below the isocenter. Results: Phantom measurements demonstrated trivial image distortion within the required field of view, and an 18K Au/Cu alloy to

  16. Outcomes of Modestly Hypofractionated Radiation for Lung Tumors: Pre- and Mid-Treatment Positron Emission Tomography-Computed Tomography Metrics as Prognostic Factors.

    Science.gov (United States)

    Harris, Jeremy P; Chang-Halpenny, Christine N; Maxim, Peter G; Quon, Andrew; Graves, Edward E; Diehn, Maximilian; Loo, Billy W

    2015-11-01

    Many patients with lung tumors have tumors too large for stereotactic ablative radiotherapy and comorbidities precluding concurrent chemotherapy. We report the outcomes of 29 patients treated with hypofractionated radiotherapy (RT) to 60 to 66 Gy in 3-Gy fractions. We also report an exploratory analysis of the prognostic value of the pre- and mid-RT positron emission tomography-computed tomography. Modestly hypofractionated radiation therapy (HypoRT; 60-66 Gy in 3-Gy fractions) allows patients with locally advanced thoracic tumors and poor performance status to complete treatment within a shorter period without concurrent chemotherapy. We evaluated the outcomes and imaging prognostic factors of HypoRT. We retrospectively reviewed the data from all patients with primary and metastatic intrathoracic tumors treated with HypoRT from 2006 to 2012. We analyzed the survival and toxicity outcomes, including overall survival (OS), progression-free survival (PFS), local recurrence (LR), and distant metastasis. We also evaluated the following tumor metrics in an exploratory analysis: gross tumor volume (GTV), maximum standardized uptake value (SUVMax), and metabolic tumor volume using a threshold of ≥ 50% of the SUVMax (MTV50%) or the maximum gradient of fluorine-18 fluorodeoxyglucose uptake (MTVEdge). We assessed the association of these metrics and their changes from before to mid-RT using positron emission tomography-computed tomography (PET-CT) with OS and PFS. We identified 29 patients, all with pre-RT and 20 with mid-RT PET-CT scans. The median follow-up period was 15 months. The 2-year overall and non-small-cell lung cancer-only rate for OS, PFS, and LR, was 59% and 59%, 52% and 41%, and 27% and 32%, respectively. No grade ≥ 3 toxicities developed. The median decrease in GTV, SUVMax, and MTVEdge was 11%, 24%, and 18%, respectively. Inferior OS was associated with a larger pre-RT MTVEdge (P = .005) and pre-RT MTV50% (P = .007). Inferior PFS was associated with a

  17. Individualized Nonadaptive and Online-Adaptive Intensity-Modulated Radiotherapy Treatment Strategies for Cervical Cancer Patients Based on Pretreatment Acquired Variable Bladder Filling Computed Tomography Scans

    International Nuclear Information System (INIS)

    Bondar, M.L.; Hoogeman, M.S.; Mens, J.W.; Quint, S.; Ahmad, R.; Dhawtal, G.; Heijmen, B.J.

    2012-01-01

    Purpose: To design and evaluate individualized nonadaptive and online-adaptive strategies based on a pretreatment established motion model for the highly deformable target volume in cervical cancer patients. Methods and Materials: For 14 patients, nine to ten variable bladder filling computed tomography (CT) scans were acquired at pretreatment and after 40 Gy. Individualized model-based internal target volumes (mbITVs) accounting for the cervix and uterus motion due to bladder volume changes were generated by using a motion-model constructed from two pretreatment CT scans (full and empty bladder). Two individualized strategies were designed: a nonadaptive strategy, using an mbITV accounting for the full-range of bladder volume changes throughout the treatment; and an online-adaptive strategy, using mbITVs of bladder volume subranges to construct a library of plans. The latter adapts the treatment online by selecting the plan-of-the-day from the library based on the measured bladder volume. The individualized strategies were evaluated by the seven to eight CT scans not used for mbITVs construction, and compared with a population-based approach. Geometric uniform margins around planning cervix–uterus and mbITVs were determined to ensure adequate coverage. For each strategy, the percentage of the cervix–uterus, bladder, and rectum volumes inside the planning target volume (PTV), and the clinical target volume (CTV)-to-PTV volume (volume difference between PTV and CTV) were calculated. Results: The margin for the population-based approach was 38 mm and for the individualized strategies was 7 to 10 mm. Compared with the population-based approach, the individualized nonadaptive strategy decreased the CTV-to-PTV volume by 48% ± 6% and the percentage of bladder and rectum inside the PTV by 5% to 45% and 26% to 74% (p < 0.001), respectively. Replacing the individualized nonadaptive strategy by an online-adaptive, two-plan library further decreased the percentage of

  18. Periapical and endodontic status scale based on periapical bone lesions and endodontic treatment quality evaluation using cone-beam computed tomography.

    Science.gov (United States)

    Venskutonis, Tadas; Plotino, Gianluca; Tocci, Luigi; Gambarini, Gianluca; Maminskas, Julius; Juodzbalys, Gintaras

    2015-02-01

    The purpose of this study was to present a new periapical and endodontic status scale (PESS) that is based on the complex periapical index (COPI), which was designed for the identification and classification of periapical bone lesions in cases of apical periodontitis, and the endodontically treated tooth index, which was designed for endodontic treatment quality evaluation by means of cone-beam computed tomographic (CBCT) analysis. Periapical and endodontic status parameters were selected from the already known indexes and scientific literature for radiologic evaluation. Radiographic images (CBCT imaging, digital orthopantomography [DOR], and digital periapical radiography) from 55 patients were analyzed. All parameters were evaluated on CBCT, DOR, and digital periapical radiographic images by 2 external observers. The statistical analysis was performed with software SPSS version 19.0 (SPSS Inc, Chicago, IL). Chi-square tests were used to compare frequencies of qualitative variables. The level of significance was set at P ≤ .05. Overall intraobserver and interobserver agreements were very good and good, respectively. CBCT analysis found more lesions and lesions of bigger dimension (P < .001). CBCT imaging was also superior in locating lesions in the apical part on the side compared with DOR and in the diagnosis of cortical bone destruction compared with both methods (P < .001). Through CBCT analysis, more root canals and more canals associated with lesions were found. The most informative and reproducible periapical and endodontic status parameters were selected, and a new PESS was proposed. The classification proposed in the present study seems to be reproducible and objective and adds helpful information with respect to the existing indexes. Future studies need to be conducted to validate PESS. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Review of quantum computation

    International Nuclear Information System (INIS)

    Lloyd, S.

    1992-01-01

    Digital computers are machines that can be programmed to perform logical and arithmetical operations. Contemporary digital computers are ''universal,'' in the sense that a program that runs on one computer can, if properly compiled, run on any other computer that has access to enough memory space and time. Any one universal computer can simulate the operation of any other; and the set of tasks that any such machine can perform is common to all universal machines. Since Bennett's discovery that computation can be carried out in a non-dissipative fashion, a number of Hamiltonian quantum-mechanical systems have been proposed whose time-evolutions over discrete intervals are equivalent to those of specific universal computers. The first quantum-mechanical treatment of computers was given by Benioff, who exhibited a Hamiltonian system with a basis whose members corresponded to the logical states of a Turing machine. In order to make the Hamiltonian local, in the sense that its structure depended only on the part of the computation being performed at that time, Benioff found it necessary to make the Hamiltonian time-dependent. Feynman discovered a way to make the computational Hamiltonian both local and time-independent by incorporating the direction of computation in the initial condition. In Feynman's quantum computer, the program is a carefully prepared wave packet that propagates through different computational states. Deutsch presented a quantum computer that exploits the possibility of existing in a superposition of computational states to perform tasks that a classical computer cannot, such as generating purely random numbers, and carrying out superpositions of computations as a method of parallel processing. In this paper, we show that such computers, by virtue of their common function, possess a common form for their quantum dynamics

  20. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  1. Optical Computing

    OpenAIRE

    Woods, Damien; Naughton, Thomas J.

    2008-01-01

    We consider optical computers that encode data using images and compute by transforming such images. We give an overview of a number of such optical computing architectures, including descriptions of the type of hardware commonly used in optical computing, as well as some of the computational efficiencies of optical devices. We go on to discuss optical computing from the point of view of computational complexity theory, with the aim of putting some old, and some very recent, re...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ...

  5. Fault tolerant computing systems

    International Nuclear Information System (INIS)

    Randell, B.

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (orig.)

  6. Computer group

    International Nuclear Information System (INIS)

    Bauer, H.; Black, I.; Heusler, A.; Hoeptner, G.; Krafft, F.; Lang, R.; Moellenkamp, R.; Mueller, W.; Mueller, W.F.; Schati, C.; Schmidt, A.; Schwind, D.; Weber, G.

    1983-01-01

    The computer groups has been reorganized to take charge for the general purpose computers DEC10 and VAX and the computer network (Dataswitch, DECnet, IBM - connections to GSI and IPP, preparation for Datex-P). (orig.)

  7. Computer Engineers.

    Science.gov (United States)

    Moncarz, Roger

    2000-01-01

    Looks at computer engineers and describes their job, employment outlook, earnings, and training and qualifications. Provides a list of resources related to computer engineering careers and the computer industry. (JOW)

  8. Learning by computer simulation does not lead to better test performance than textbook study in the diagnosis and treatment of dysrhythmias.

    Science.gov (United States)

    Kim, Jong Hoon; Kim, Won Oak; Min, Kyeong Tae; Yang, Jong Yoon; Nam, Yong Taek

    2002-08-01

    To compare computer-based learning with traditional learning methods in studying advanced cardiac life support (ACLS). Prospective, randomized study. University hospital. Senior medical students were randomized to perform computer simulation and textbook study. Each group studied ACLS for 150 minutes. Tests were performed 1 week before, immediately after, and 1 week after the study period. Testing consisted of 20 questions. All questions were formulated in such a way that there was a single best answer. Each student also completed a questionnaire designed to assess computer skills, as well as satisfaction with and benefit from the study materials. Test scores improved after both textbook study and computer simulation study in both groups, although the improvement in scores was significantly higher for the textbook group only immediately after the study. There was no significant difference between groups in their computer skill and satisfaction with the study materials. The textbook group reported greater benefit from study materials than did the computer simulation group. Studying ACLS with a hard-copy textbook may be more effective than computer simulation for acquiring simple information during a brief period. However, the difference in effectiveness is likely transient.

  9. Optical coherence tomography based microangiography for quantitative monitoring of structural and vascular changes in a rat model of acute uveitis in vivo: a preliminary study

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-01-01

    Uveitis models in rodents are important in the investigation of pathogenesis in human uveitis and the development of appropriate therapeutic strategies for treatment. Quantitative monitoring of ocular inflammation in small animal models provides an objective metric to assess uveitis progression and/or therapeutic effects. We present a new application of optical coherence tomography (OCT) and OCT-based microangiography (OMAG) to a rat model of acute anterior uveitis induced by intravitreal injection of a killed mycobacterial extract. OCT/OMAG is used to provide noninvasive three-dimensional imaging of the anterior segment of the eyes prior to injection (baseline) and two days post-injection (peak inflammation) in rats with and without steroid treatments. OCT imaging identifies characteristic structural and vascular changes in the anterior segment of the inflamed animals when compared to baseline images. Characteristics of inflammation identified include anterior chamber cells, corneal edema, pupillary membranes, and iris vasodilation. In contrast, no significant difference from the control is observed for the steroid-treated eye. These findings are compared with the histology assessment of the same eyes. In addition, quantitative measurements of central corneal thickness and iris vessel diameter are determined. This pilot study demonstrates that OCT-based microangiography promises to be a useful tool for the assessment and management of uveitis in vivo.

  10. Computer Music

    Science.gov (United States)

    Cook, Perry R.

    This chapter covers algorithms, technologies, computer languages, and systems for computer music. Computer music involves the application of computers and other digital/electronic technologies to music composition, performance, theory, history, and the study of perception. The field combines digital signal processing, computational algorithms, computer languages, hardware and software systems, acoustics, psychoacoustics (low-level perception of sounds from the raw acoustic signal), and music cognition (higher-level perception of musical style, form, emotion, etc.).

  11. Variance in predicted cup size by 2-dimensional vs 3-dimensional computerized tomography-based templating in primary total hip arthroplasty.

    Science.gov (United States)

    Osmani, Feroz A; Thakkar, Savyasachi; Ramme, Austin; Elbuluk, Ameer; Wojack, Paul; Vigdorchik, Jonathan M

    2017-12-01

    Preoperative total hip arthroplasty templating can be performed with radiographs using acetate prints, digital viewing software, or with computed tomography (CT) images. Our hypothesis is that 3D templating is more precise and accurate with cup size prediction as compared to 2D templating with acetate prints and digital templating software. Data collected from 45 patients undergoing robotic-assisted total hip arthroplasty compared cup sizes templated on acetate prints and OrthoView software to MAKOplasty software that uses CT scan. Kappa analysis determined strength of agreement between each templating modality and the final size used. t tests compared mean cup-size variance from the final size for each templating technique. Interclass correlation coefficient (ICC) determined reliability of digital and acetate planning by comparing predictions of the operating surgeon and a blinded adult reconstructive fellow. The Kappa values for CT-guided, digital, and acetate templating with the final size was 0.974, 0.233, and 0.262, respectively. Both digital and acetate templating significantly overpredicted cup size, compared to CT-guided methods ( P cup size when compared to the significant overpredictions of digital and acetate templating. CT-guided templating may also lead to better outcomes due to bone stock preservation from a smaller and more accurate cup size predicted than that of digital and acetate predictions.

  12. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  13. Computational composites

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.; Redström, Johan

    2007-01-01

    Computational composite is introduced as a new type of composite material. Arguing that this is not just a metaphorical maneuver, we provide an analysis of computational technology as material in design, which shows how computers share important characteristics with other materials used in design...... and architecture. We argue that the notion of computational composites provides a precise understanding of the computer as material, and of how computations need to be combined with other materials to come to expression as material. Besides working as an analysis of computers from a designer’s point of view......, the notion of computational composites may also provide a link for computer science and human-computer interaction to an increasingly rapid development and use of new materials in design and architecture....

  14. Quantum Computing

    OpenAIRE

    Scarani, Valerio

    1998-01-01

    The aim of this thesis was to explain what quantum computing is. The information for the thesis was gathered from books, scientific publications, and news articles. The analysis of the information revealed that quantum computing can be broken down to three areas: theories behind quantum computing explaining the structure of a quantum computer, known quantum algorithms, and the actual physical realizations of a quantum computer. The thesis reveals that moving from classical memor...

  15. Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; d'Amore, Francesco; Mylam, Karen Juul

    2012-01-01

    PURPOSETo investigate whether bone marrow biopsy (BMB) adds useful information to [(18)F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) staging in patients with Hodgkin lymphoma (HL). PATIENTS AND METHODSNewly diagnosed patients with HL undergoing a pretherapeu...

  16. Clinical applications of cone beam computed tomography in endodontics: a comprehensive review. Part 1: applications associated with endodontic treatment and diagnosis

    NARCIS (Netherlands)

    Cohenca, N.; Shemesh, H.

    2015-01-01

    Cone beam computed tomography (CBCT) is a new technology that produces three-dimensional (3D) digital imaging at reduced cost and less radiation for the patient than traditional CT scans. It also delivers faster and easier image acquisition. By providing a 3D representation of the maxillofacial

  17. Conformal treatment of prostate cancer with improved targeting: superior prostate-specific antigen response compared to standard treatment

    Energy Technology Data Exchange (ETDEWEB)

    Corn, Benjamin W; Hanks, Gerald E; Schultheiss, Timothy E; Hunt, Margie A; Lee, W Robert; Coia, Lawrence R

    1995-05-15

    Purpose: Conformal radiation therapy (CRT) decreases the morbidity of prostate cancer treatment, but no published data attest to the improved ability of CRT to control disease. Therefore, we compared Prostate-Specific Antigen (PSA) response at 1 year among similarly staged patients treated by conformal techniques to those treated with conventional approaches, looking for an early indicator of tumor response. Method and Materials: Patients with locally advanced disease were treated by pelvic fields followed by prostate field conedowns; those with early stage/low grade disease received only prostate field irradiation. Between October, 1987 and November, 1991, conventional treatments used rectangular beams with or without corner blocks. Neither urethrography nor immobilization casts were used for conventionally treated patients. Between April, 1989 and December, 1992, conformal treatments have used rigid immobilization and Computed Tomography-based, beams-eye-view field design. As such, our conformal approach allowed improved targeting. Median prescribed doses (minimal doses to the Planning Target Volume) were 70 Gy (66-73 Gy) and 70.2 Gy (64.8-75 Gy) for conventionally and conformally treated patients, respectively. Median daily fraction size was 1.8 Gy for conventional treatment and 2.0 Gy for conformal therapy. Baseline PSA data were available on 170 consecutive patients treated conformally and 90 consecutive patients treated conventionally. Results: Among those receiving only prostatic field irradiation, 12-month PSA values returned to normal in 96% and 85% of conformally and conventionally treated patients, respectively, when normalization was defined as {<=} 4 ng/ml (p < 0.03) and in 76% vs. 55% of patients when PSA normalization was defined as {<=} 1.5 ng/ml (p < 0.02). Among those receiving pelvic irradiation prior to prostatic conedown, PSA normalization ({<=} 4 ng/ml) occurred in 82% and 61% (p < 0.01) of conformally and conventionally treated patients

  18. Computational Medicine

    DEFF Research Database (Denmark)

    Nygaard, Jens Vinge

    2017-01-01

    The Health Technology Program at Aarhus University applies computational biology to investigate the heterogeneity of tumours......The Health Technology Program at Aarhus University applies computational biology to investigate the heterogeneity of tumours...

  19. Grid Computing

    Indian Academy of Sciences (India)

    A computing grid interconnects resources such as high performancecomputers, scientific databases, and computercontrolledscientific instruments of cooperating organizationseach of which is autonomous. It precedes and is quitedifferent from cloud computing, which provides computingresources by vendors to customers ...

  20. Green Computing

    Directory of Open Access Journals (Sweden)

    K. Shalini

    2013-01-01

    Full Text Available Green computing is all about using computers in a smarter and eco-friendly way. It is the environmentally responsible use of computers and related resources which includes the implementation of energy-efficient central processing units, servers and peripherals as well as reduced resource consumption and proper disposal of electronic waste .Computers certainly make up a large part of many people lives and traditionally are extremely damaging to the environment. Manufacturers of computer and its parts have been espousing the green cause to help protect environment from computers and electronic waste in any way.Research continues into key areas such as making the use of computers as energy-efficient as Possible, and designing algorithms and systems for efficiency-related computer technologies.

  1. Introduction to computer networking

    CERN Document Server

    Robertazzi, Thomas G

    2017-01-01

    This book gives a broad look at both fundamental networking technology and new areas that support it and use it. It is a concise introduction to the most prominent, recent technological topics in computer networking. Topics include network technology such as wired and wireless networks, enabling technologies such as data centers, software defined networking, cloud and grid computing and applications such as networks on chips, space networking and network security. The accessible writing style and non-mathematical treatment makes this a useful book for the student, network and communications engineer, computer scientist and IT professional. • Features a concise, accessible treatment of computer networking, focusing on new technological topics; • Provides non-mathematical introduction to networks in their most common forms today;< • Includes new developments in switching, optical networks, WiFi, Bluetooth, LTE, 5G, and quantum cryptography.

  2. Quantum computers and quantum computations

    International Nuclear Information System (INIS)

    Valiev, Kamil' A

    2005-01-01

    This review outlines the principles of operation of quantum computers and their elements. The theory of ideal computers that do not interact with the environment and are immune to quantum decohering processes is presented. Decohering processes in quantum computers are investigated. The review considers methods for correcting quantum computing errors arising from the decoherence of the state of the quantum computer, as well as possible methods for the suppression of the decohering processes. A brief enumeration of proposed quantum computer realizations concludes the review. (reviews of topical problems)

  3. Quantum Computing for Computer Architects

    CERN Document Server

    Metodi, Tzvetan

    2011-01-01

    Quantum computers can (in theory) solve certain problems far faster than a classical computer running any known classical algorithm. While existing technologies for building quantum computers are in their infancy, it is not too early to consider their scalability and reliability in the context of the design of large-scale quantum computers. To architect such systems, one must understand what it takes to design and model a balanced, fault-tolerant quantum computer architecture. The goal of this lecture is to provide architectural abstractions for the design of a quantum computer and to explore

  4. Pervasive Computing

    NARCIS (Netherlands)

    Silvis-Cividjian, N.

    This book provides a concise introduction to Pervasive Computing, otherwise known as Internet of Things (IoT) and Ubiquitous Computing (Ubicomp) which addresses the seamless integration of computing systems within everyday objects. By introducing the core topics and exploring assistive pervasive

  5. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  6. Spatial Computation

    Science.gov (United States)

    2003-12-01

    Computation and today’s microprocessors with the approach to operating system architecture, and the controversy between microkernels and monolithic kernels...Both Spatial Computation and microkernels break away a relatively monolithic architecture into in- dividual lightweight pieces, well specialized...for their particular functionality. Spatial Computation removes global signals and control, in the same way microkernels remove the global address

  7. Value of computed tomography for the diagnosis and pre and post-treatment workup of aortic aneurysms. Comparison with angiographic findings. A report of data in 112 cases

    International Nuclear Information System (INIS)

    Senac, J.P.; Giron, J.; Ovchinnikoff, S.; Mourre, P.; Joffre, P.; Mary, H.; Novati, J.P.

    1987-01-01

    The authors report that CT scan provided decisive or complementary data, as compared to angiography, in 112 cases of aortic aneurysm. CT scan thus emerges as a useful tool. The inadequate angiographies were either nearly normal, or showed evidence that pointed to total arterial occlusion whose thrombotic and aneurysmal nature was demonstrated only upon computed tomography; CT scan proved irreplaceable for evaluating prostheses and postoperative complications. The axial transverse plane of CT sections explains why computed tomography is so informative: the channel, thrombosis, wall and peri-adventicia (fibrosis, fissuration) are visible successively from the center to the periphery. In the authors' opinion, the pretreatment evaluation of an aortic aneurysm should include a CT angioscan in addition to an angiography as the two procedures complement one another. After surgery, CT scan is even more widely indicated. CT scan is the primary procedure for controlling a prosthesis and often makes other investigations unnecessary [fr

  8. A novel representation of inter-site tumour heterogeneity from pre-treatment computed tomography textures classifies ovarian cancers by clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Hebert Alberto; Micco, Maura; Lakhman, Yulia; Meier, Andreas A.; Sosa, Ramon; Hricak, Hedvig; Sala, Evis [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Veeraraghavan, Harini; Deasy, Joseph [Memorial Sloan Kettering Cancer Center, Department of Medical Physics, New York, NY (United States); Nougaret, Stephanie [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Service de Radiologie, Institut Regional du Cancer de Montpellier, Montpellier (France); INSERM, U1194, Institut de Recherche en Cancerologie de Montpellier (IRCM), Montpellier (France); Soslow, Robert A.; Weigelt, Britta [Memorial Sloan Kettering Cancer Center, Department of Pathology, New York, NY (United States); Levine, Douglas A. [Memorial Sloan Kettering Cancer Center, Department of Surgery, New York, NY (United States); Aghajanian, Carol; Snyder, Alexandra [Memorial Sloan Kettering Cancer Center, Department of Medicine, New York, NY (United States)

    2017-09-15

    To evaluate the associations between clinical outcomes and radiomics-derived inter-site spatial heterogeneity metrics across multiple metastatic lesions on CT in patients with high-grade serous ovarian cancer (HGSOC). IRB-approved retrospective study of 38 HGSOC patients. All sites of suspected HGSOC involvement on preoperative CT were manually segmented. Gray-level correlation matrix-based textures were computed from each tumour site, and grouped into five clusters using a Gaussian Mixture Model. Pairwise inter-site similarities were computed, generating an inter-site similarity matrix (ISM). Inter-site texture heterogeneity metrics were computed from the ISM and compared to clinical outcomes. Of the 12 inter-site texture heterogeneity metrics evaluated, those capturing the differences in texture similarities across sites were associated with shorter overall survival (inter-site similarity entropy, similarity level cluster shade, and inter-site similarity level cluster prominence; p ≤ 0.05) and incomplete surgical resection (similarity level cluster shade, inter-site similarity level cluster prominence and inter-site cluster variance; p ≤ 0.05). Neither the total number of disease sites per patient nor the overall tumour volume per patient was associated with overall survival. Amplification of 19q12 involving cyclin E1 gene (CCNE1) predominantly occurred in patients with more heterogeneous inter-site textures. Quantitative metrics non-invasively capturing spatial inter-site heterogeneity may predict outcomes in patients with HGSOC. (orig.)

  9. Treatment Effects

    DEFF Research Database (Denmark)

    Heckman, James J.; Lopes, Hedibert F.; Piatek, Rémi

    2014-01-01

    This paper contributes to the emerging Bayesian literature on treatment effects. It derives treatment parameters in the framework of a potential outcomes model with a treatment choice equation, where the correlation between the unobservable components of the model is driven by a low-dimensional v......This paper contributes to the emerging Bayesian literature on treatment effects. It derives treatment parameters in the framework of a potential outcomes model with a treatment choice equation, where the correlation between the unobservable components of the model is driven by a low...... to observe the same person in both the treated and untreated states, but it also turns out to be straightforward to implement. Formulae are provided to compute mean treatment effects as well as their distributional versions. A Monte Carlo simulation study is carried out to illustrate how the methodology can...

  10. Parallel computations

    CERN Document Server

    1982-01-01

    Parallel Computations focuses on parallel computation, with emphasis on algorithms used in a variety of numerical and physical applications and for many different types of parallel computers. Topics covered range from vectorization of fast Fourier transforms (FFTs) and of the incomplete Cholesky conjugate gradient (ICCG) algorithm on the Cray-1 to calcul