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https://www.readbyqxmd.com/read/28102951/direct-and-fast-measurement-of-ct-beam-filter-profiles-with-simultaneous-geometrical-calibration
#1
Kai Yang, Xinhua Li, X George Xu, Bob Liu
PURPOSE: To accurately measure the beam filter profiles from a variety of CT scanner models and to provide reference data for Monte Carlo simulations of CT scanners. METHODS: This study proposed a new method to measure CT beam filter profiles using a linear-array x-ray detector (X-Scan 0.8f3-512; Detection Technology Inc., Espoo, Finland) under gantry rotation mode. A robust geometrical calibration approach was developed to determine key geometrical parameters by considering the x-ray focal spot location relative to the linear-array detector and the gantry's angular increment at each acquisition point...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102946/a-portal-dosimetry-dose-prediction-method-based-on-collapsed-cone-algorithm-using-the-clinical-beam-model
#2
J Martínez Ortega, N Gómez González, P Castro Tejero, M Pinto Monedero, N B Tolani, L Núñez Martín, R Sánchez Montero
PURPOSE: Amorphous silicon electronical portal imaging devices (EPIDs) are widely used for dosimetric measurements in Radiation Therapy. The purpose of this work was to determine if a portal dose prediction method can be utilized for dose map calculations based on the linear accelerator model within a commercial treatment planning system (Pinnacle(3) v8.0 m). METHODS: The method was developed for a 6 MV photon beam on the Varian Clinac 21-EX, at a nominal dose rate of 400 MU/min...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102942/a-platform-independent-method-to-reduce-ct-truncation-artifacts-using-discriminative-dictionary-representations
#3
Yang Chen, Adam Budde, Ke Li, Yinsheng Li, Jiang Hsieh, Guang-Hong Chen
PURPOSE: When the scan field of view (SFOV) of a CT system is not large enough to enclose the entire cross-section of the patient, or the patient needs to be positioned partially outside the SFOV for certain clinical applications, truncation artifacts often appear in the reconstructed CT images. Many truncation artifact correction methods perform extrapolations of the truncated projection data based on certain a priori assumptions. The purpose of this work was to develop a novel CT truncation artifact reduction method that directly operates on DICOM images...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102707/patient-dosimetry-audit-for-establishing-local-diagnostic-reference-levels-for-nuclear-medicine-ct
#4
Matthew Gardner, Ngonidzashe M Katsidzira, Erin Ross, Elizabeth A Larkin
OBJECTIVES: To establish a system for patient dosimetry audit and setting of Local Diagnostic Reference Levels (LDRLs) for Nuclear Medicine (NM) CT. METHODS: Computed Radiological Information System (CRIS) data were matched with NM paper records which provided the body region and dose mode for NMCT carried out at a large UK hospital. It was necessary to divide data in terms of the NM examination type, body region and dose mode. The mean and standard deviation Dose Length Products (DLPs) for common NMCT examinations were then calculated and compared to the proposed National DRLs (NDRLs)...
January 19, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28102510/influence-of-dose-reduction-and-iterative-reconstruction-on-ct-calcium-scores-a-multi-manufacturer-dynamic-phantom-study
#5
N R van der Werf, M J Willemink, T P Willems, M J W Greuter, T Leiner
To evaluate the influence of dose reduction in combination with iterative reconstruction (IR) on coronary calcium scores (CCS) in a dynamic phantom on state-of-the-art CT systems from different manufacturers. Calcified inserts in an anthropomorphic chest phantom were translated at 20 mm/s corresponding to heart rates between 60 and 75 bpm. The inserts were scanned five times with routinely used CCS protocols at reference dose and 40 and 80% dose reduction on four high-end CT systems. Filtered back projection (FBP) and increasing levels of IR were applied...
January 19, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28102447/analysing-a-mechanism-of-failure-in-retrieved-magnetically-controlled-spinal-rods
#6
Vasiliki C Panagiotopoulou, Stewart K Tucker, Robert K Whittaker, Harry S Hothi, Johann Henckel, Julian J H Leong, Thomas Ember, John A Skinner, Alister J Hart
PURPOSE: We aim to describe a mechanism of failure in magnetically controlled growth rods which are used for the correction of the early onset scoliosis. METHODS: This retrieval study involved nine magnetically controlled growth rods, of a single design, revised from five patients for metal staining, progression of scoliosis, swelling, fractured actuator pin, and final fusion. All the retrieved rods were radiographed and assessed macroscopically and microscopically for material loss...
January 19, 2017: European Spine Journal
https://www.readbyqxmd.com/read/28101916/perceptions-of-cancer-of-unknown-primary-site-a-national-survey-of-australian-medical-oncologists
#7
Christos S Karapetis, Lisa Guccione, Martin Hn Tattersall, Helen Gooden, Claire M Vajdic, Sylvie Lambert, Monica Robotin, Linda Mileshkin, Penelope Schofield
INTRODUCTION: Despite being the 6(th) cause of cancer death in Australia, cancer of unknown primary (CUP) site remains poorly understood. AIMS: To describe practices relating to the diagnosis, investigation, classification, communication and management of CUP amongst medical oncologists. METHODS: We invited all members of the Medical Oncology Group of Australia to participate in a national, anonymous online survey about CUP. The survey collected data regarding diagnosis acceptance, diagnostic tests, treatment protocols and communication practices around the diagnosis of CUP...
January 19, 2017: Internal Medicine Journal
https://www.readbyqxmd.com/read/28101760/a-cad-of-fully-automated-colonic-polyp-detection-for-contrasted-and-non-contrasted-ct-scans
#8
Gökalp Tulum, Bülent Bolat, Onur Osman
PURPOSE: Computer-aided detection (CAD) systems are developed to help radiologists detect colonic polyps over CT scans. It is possible to reduce the detection time and increase the detection accuracy rates by using CAD systems. In this paper, we aimed to develop a fully integrated CAD system for automated detection of polyps that yields a high polyp detection rate with a reasonable number of false positives. METHODS: The proposed CAD system is a multistage implementation whose main components are: automatic colon segmentation, candidate detection, feature extraction and classification...
January 18, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28101631/lumbar-and-sacral-pedicle-screw-placement-using-a-template-does-not-improve-the-midterm-pain-and-disability-outcome-in-comparison-with-free-hand-method
#9
Matjaz Merc, Gregor Recnik, Zmago Krajnc
BACKGROUND: The free-hand technique carries a higher risk of pedicle weakening and neurovascular injuries in comparison with pedicle screw placement using a drill guide. Due to this evidence and because of some variances in the surgical method, different outcome can be expected. The objective of the study was to evaluate the disability, the back and leg pain before and at least 3 years after the surgery between examined groups. MATERIALS AND METHODS: Eleven patients in drill guide and 13 in control group were randomly assigned for vertebral fusion in the lumbar and first sacral regions...
January 19, 2017: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
https://www.readbyqxmd.com/read/28101491/can-the-american-thyroid-association-risk-of-recurrence-predict-radioiodine-refractory-disease-in-differentiated-thyroid-cancer
#10
Aamna Hassan, Saima Riaz, Humayun Bashir, M Khalid Nawaz, Raza Hussain
OBJECTIVE: The aim of this study was to compare the TNM staging system and the American Thyroid Association (ATA) recurrence risk classification in predicting radioiodine refractory disease (RRD) in differentiated thyroid cancer (DTC) and to analyze the correlation of stimulated thyroglobulin (Tg) levels and rate of Tg elevation with the standardized uptake value on (18)F-fludeoxyglucose (FDG) PET/CT scan. METHODS: RRD was indicated through the retrospective analysis of consecutive (18)F-FDG PET/CT scans in DTC with stimulated Tg >10 ng/ml and negative (131)I NaI whole-body scans (WBS)...
December 2016: European Thyroid Journal
https://www.readbyqxmd.com/read/28101203/short-term-effect-analysis-of-radiofrequency-ablation-combined-chemotherapy-on-middle-and-late-period-non-small-cell-lung-cancer
#11
Shuo Yu, Zhen Zhou Wu, Hong Tao Si, Sai Yang, Guang Mao Liu, Xiao Dong Zhao
In this study, we investigated the effect of radiofrequency ablation (RFA) combined chemotherapy on middle and late period non-small cell lung cancer (NSCLC). In total, 85 cases of middle and late period NSCLC patients were selected, and were randomly divided into the RFA combined chemotherapy group, RFA treatment group and chemotherapy group. After treatment, the three groups were followed up for computed tomography (CT) scan, and were analyzed for the effect of RFA combined chemotherapy on middle and late period NSCLC...
December 2016: Oncology Letters
https://www.readbyqxmd.com/read/28101168/ct-guided-125-i-seed-implantation-for-inoperable-retroperitoneal-sarcoma-a-technique-for-delivery-of-local-tumor-brachytherapy
#12
Biao Yang, Wen-Hao Guo, Ting Lan, Fang Yuan, Guan-Jian Liu, Rui-Yu Zan, Xin You, Qiao-Yue Tan, Zheng-Yin Liao
Radical surgery is currently the first treatment of choice for retroperitoneal soft tissue sarcoma (RSTS). However, the prognosis of RSTS remains poor due to ineffective local control and a high incidence of metastasis after surgical resection. Brachytherapy has been shown to safely provide local radiotherapy for numerous types of cancer when used alone or in combination with surgical resection, but has not been well characterized in the management of RSTS. The aim of this study was to evaluate CT-guided 125I seed implantation for local control and pain relief in the treatment of inoperable RSTS...
December 2016: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28100995/a-rare-case-of-intraductal-papillary-mucinous-neoplasm-of-the-biliary-duct-in-a-patient-with-prostate-adenocarcinoma
#13
Ravish Parekh, Gregory Krol, Cyrus Piraka, Surinder Batra
Intraductal papillary mucinous neoplasms (IPMNs) are mucin-producing papillary neoplasms of the pancreatic or biliary ductal system that exhibit variable cellular atypia and cause ductal dilation. There are few reported cases of IPMN arising from the biliary tree in the literature. It has a higher propensity to undergo malignant transformation compared to IPMN arising from the pancreatic duct. An 80-year-old male underwent cross-sectional tomography (CT) imaging of the abdomen for evaluation of prostate adenocarcinoma, which revealed an incidental 2...
September 2016: Case Reports in Gastroenterology
https://www.readbyqxmd.com/read/28100994/reocclusion-after-self-expandable-metallic-stent-placement-for-relieving-malignant-colorectal-obstruction-as-a-palliative-treatment
#14
Toshikatsu Nitta, Kensuke Fujii, Yoshimasa Hirata, Tomo Tominaga, Yoshihiro Inoue, Hiroshi Kawasaki, Ken Kawakami, Takashi Ishibashi
Self-expandable metallic stent (SEMS) placement has been practiced in several hospitals in Japan, including ours, since January 2012. Here, we report the case of an 82-year-old Japanese man who presented to the hospital with a 1-week history of right hypochondrial pain. Computed tomography (CT) findings indicated colorectal cancer. The laboratory findings on admission indicated severe anemia (red blood cell count, 426 × 104/μL; hemoglobin, 7.9 g/dL). We performed SEMS placement because the patient refused to undergo surgery...
September 2016: Case Reports in Gastroenterology
https://www.readbyqxmd.com/read/28100723/a-respiratory-gated-micro-ct-comparison-of-respiratory-patterns-in-free-breathing-and-mechanically-ventilated-rats
#15
Nancy L Ford, Lynda McCaig, Andrew Jeklin, James F Lewis, Ruud A W Veldhuizen, David W Holdsworth, Maria Drangova
In this study, we aim to quantify the differences in lung metrics measured in free-breathing and mechanically ventilated rodents using respiratory-gated micro-computed tomography. Healthy male Sprague-Dawley rats were anesthetized with ketamine/xylazine and scanned with a retrospective respiratory gating protocol on a GE Locus Ultra micro-CT scanner. Each animal was scanned while free-breathing, then intubated and mechanically ventilated (MV) and rescanned with a standard ventilation protocol (56 bpm, 8 mL/kg and PEEP of 5 cm H2O) and again with a ventilation protocol that approximates the free-breathing parameters (88 bpm, 2...
January 2017: Physiological Reports
https://www.readbyqxmd.com/read/28100235/solitary-fibrous-tumour-of-the-liver-report-on-metastasis-and-local-recurrence-of-a-malignant-case-and-review-of-literature
#16
REVIEW
Nelson Chen, Kellee Slater
BACKGROUND: Solitary fibrous tumours (SFT) are neoplasms of mesenchymal origin that predominantly arise from the pleura. SFT of the liver (SFTL) are a rare occurrence with little number of cases reported in English literature. Malignant cases of hepatic SFT are an even rarer occurrence. For this reason, the prognostic evaluation of SFTLs is unknown and difficult to measure. METHODS: A search on English literature on "Solitary Fibrous Tumour of the Liver" was conducted on common search engines (PubMed, Google)...
January 18, 2017: World Journal of Surgical Oncology
https://www.readbyqxmd.com/read/28099616/do-you-know-this-syndrome-type-2-benign-symmetric-lipomatosis-launois-bensaude
#17
Ana Cláudia Cavalcante Esposito, Tania Munhoz, Luciana Patrícia Fernandes Abbade, Hélio Amante Miot
A 57-year-old female showed bulky, loose tumors, which progressively spread to her arms, anterior chest, and back. She reported dysphagia and dyspnea after mild exertion. She denied alcohol consumption. CT scan of her chest showed no internal lesions. Benign symmetric lipomatosis is a rare syndrome, clinically described as multiple nonencapsulated lipomas of various sizes and symmetrical distribution. This syndrome has three known phenotypes; in type 2 (Launois-Bensaude syndrome), lesions occur primarily on the shoulders, upper arms, and chest, and is unrelated to alcoholism...
November 2016: Anais Brasileiros de Dermatologia
https://www.readbyqxmd.com/read/28099380/predicting-appendiceal-tumors-among-patients-with-appendicitis
#18
Tyler J Loftus, Steven L Raymond, George A Sarosi, Chasen A Croft, R Stephen Smith, Philip A Efron, Frederick A Moore, Scott C Brakenridge, Alicia M Mohr, Janeen R Jordan
BACKGROUND: As non-operative management of appendicitis gains popularity, vigilance for appendiceal tumors becomes increasingly important. We hypothesized that among patients presenting with acute appendicitis, those with advanced age, multiple comorbidities, atypical presentation, and complicated appendicitis would be more likely to have underlying appendiceal tumors. METHODS: We performed a 4-year retrospective cohort analysis of 677 consecutive adult patients who underwent appendectomy for appendicitis at our tertiary care center...
January 17, 2017: Journal of Trauma and Acute Care Surgery
https://www.readbyqxmd.com/read/28099335/micronodular-pattern-of-organizing-pneumonia-case-report-and-systematic-literature-review
#19
François Lebargy, Davy Picard, Jean Hagenburg, Olivier Toubas, Jeanne-Marie Perotin, Sebastian Sandu, Gaëtan Deslee, Sandra Dury
RATIONALE: Organizing pneumonia (OP) is a clinicopathological entity characterized by granulation tissue plugs in the lumen of small airways, alveolar ducts, and alveoli. OP can be cryptogenic (primary) (COP) or secondary to various lung injuries. PATIENT CONCERNS: We report the case of a 38-year-old male smoker with COP presenting in the form of diffuse micronodules on computed tomography (CT) scan and describe the clinical, radiological, and functional characteristics of micronodular pattern of organizing pneumonia (MNOP) based on a review of the literature including 14 cases...
January 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28099304/three-dimensional-analysis-of-acute-scaphoid-fracture-displacement-proximal-extension-deformity-of-the-scaphoid
#20
Yonatan Schwarcz, Yael Schwarcz, Eran Peleg, Leo Joskowicz, Ronit Wollstein, Shai Luria
BACKGROUND: Our goal was to analyze the movement of acute scaphoid waist fracture fragments and adjacent bones in a common coordinate system. Our hypothesis was that the distal scaphoid fragment flexes and pronates and the proximal fragment extends. METHODS: Computed tomography (CT) scans of patients diagnosed with an acute scaphoid waist fracture were evaluated using a 3-dimensional (3D) model. The scans of 57 nondisplaced and 23 displaced fractures were compared with a control group of 27 scans showing no pathological involvement of the wrist...
January 18, 2017: Journal of Bone and Joint Surgery. American Volume
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