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https://www.readbyqxmd.com/read/28994668/correction-of-patient-motion-in-cone-beam-ct-using-3d-2d-registration
#1
Sarah Ouadah, Matthew W Jacobson, Joseph Webster Stayman, Tina Ehtiati, Clifford Raabe Weiss, Jeffrey H Siewerdsen
Cone-beam CT (CBCT) is increasingly common in guidance of interventional procedures but can be subject to artifacts arising from patient motion during fairly long (~5-60s) scan times. We present a fiducial-free method to mitigate motion artifacts using 3D-2D image registration that simultaneously corrects residual errors in the intrinsic and extrinsic parameters of geometric calibration. The 3D-2D registration process registers each projection to a prior 3D image by maximizing gradient orientation using the covariance matrix adaptation-evolution strategy (CMA-ES) optimizer...
October 10, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28989218/geometric-calibration-using-line-fiducials-for-cone-beam-ct-with-general-non-circular-source-detector-trajectories
#2
M W Jacobson, M Ketcha, A Uneri, J Goerres, T De Silva, S Reaungamornrat, S Vogt, G Kleinszig, J H Siewerdsen
PURPOSE: Traditional BB-based geometric calibration methods for cone-beam CT (CBCT) rely strongly on foreknowledge of the scan trajectory shape. This is a hindrance to the implementation of variable trajectory CBCT systems, normally requiring a dedicated calibration phantom or software algorithm for every scan orbit of interest. A more flexible method of calibration is proposed here that accommodates multiple orbit types - including strongly noncircular trajectories - with a single phantom and software routine...
March 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28988856/a-3d-printed-modular-device-for-imaging-the-brain-of-small-birds
#3
Christine R Lattin, Maxwell A Emerson, Jean-Dominique Gallezot, Tim Mulnix, J Elliott Brown, Richard E Carson
BACKGROUND: One potential barrier to using in vivo imaging in any new animal species is solving the basic problem of how to hold animals safely and securely during scans. NEW METHOD: In this paper, we describe the design, fabrication, use, and positional reproducibility of a 3D-printed plastic device (the Avian Imaging Device, or AID) for imaging the brain of 1 or 2 small songbirds. We designed two different types of head cones to use with this device: one that was not contoured and designed for anesthesia induction, and one contoured to the shape of a house sparrow head, designed to be used with a pre-anesthetized animal...
October 6, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28988675/application-of-geant4-monte-carlo-simulation-in-dose-calculations-for-small-radiosurgical-fields
#4
Somayeh Gholami, Francesco Longo, Hassan Ali Nedaie, Alessio Berti, Mehdi Mousavi, Ali S Meigooni
The Geant4 toolkit was used to develop a Monte Carlo (MC)-based engine for accurate dose calculations in small radiation field sizes. The Geant4 toolkit (version 10.1.p02) was used to simulate 6-MV photon beam of a Varian2100C linear accelerator that is being used for stereotactic radiosurgery (SRS) treatment with small radiation fields. Geometric models of 3 in-house designed radiosurgical divergent cones, with the diameters of their projections at the isocenter being 10, 20, and 30 mm, were simulated. The accuracy of the MC simulation technique was examined by reproducing several different simulated dosimetric parameters of the primary beams with the experimental data...
October 4, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/28986644/traumatic-occipito-cervical-dissociation-in-adults-a-middle-eastern-cohort-study
#5
K Venugopal Menon, Ismail Al Habsi, Khalifa Al Ghafri
The objective of this study is to describe a series of cranio-cervical dissociation victims and evaluate their outcomes as well as discuss the clinical dilemmas we faced in the context of current literature evidence. This is a retrospective cohort study of traumatic occipito-cervical dissociation in five patients (three males and two females) encountered between 2010 and 2016 at a tertiary care facility in the Middle East region. All patients underwent occipito-cervical fusion using screws and rods system with mean postoperative follow-up period of 2...
October 6, 2017: European Journal of Orthopaedic Surgery & Traumatology: Orthopédie Traumatologie
https://www.readbyqxmd.com/read/28982793/photon-counting-ct-of-the-brain-in-vivo-human-results-and-image-quality-assessment
#6
A Pourmorteza, R Symons, D S Reich, M Bagheri, T E Cork, S Kappler, S Ulzheimer, D A Bluemke
BACKGROUND AND PURPOSE: Photon-counting detectors offer the potential for improved image quality for brain CT but have not yet been evaluated in vivo. The purpose of this study was to compare photon-counting detector CT with conventional energy-integrating detector CT for human brains. MATERIALS AND METHODS: Radiation dose-matched energy-integrating detector and photon-counting detector head CT scans were acquired with standardized protocols (tube voltage/current, 120 kV(peak)/370 mAs) in both an anthropomorphic head phantom and 21 human asymptomatic volunteers (mean age, 58...
October 5, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28979598/evaluation-and-management-of-failed-shoulder-instability-surgery
#7
António Cartucho, Nuno Moura, Marco Sarmento
BACKGROUND: Failed shoulder instability surgery is mostly considered to be the recurrence of shoulder dislocation but subluxation, painful or non-reliable shoulder are also reasons for patient dissatisfaction and should be considered in the notion. METHODS: The authors performed a revision of the literature and online contents on evaluation and management of failed shoulder instability surgery. RESULTS: When we look at the reasons for failure of shoulder instability surgery we point the finger at poor patient selection, technical error and an additional traumatic event...
2017: Open Orthopaedics Journal
https://www.readbyqxmd.com/read/28974353/growth-curves-for-intracranial-volume-in-normal-asian-children-fortify-management-of-craniosynostosis
#8
Hideaki Kamochi, Ataru Sunaga, Daekwan Chi, Rintaro Asahi, Shiho Nakagawa, Masanori Mori, Hirokazu Uda, Shunji Sarukawa, Yasushi Sugawara, Kotaro Yoshimura
BACKGROUND: Although the charting of normal intracranial volume (ICV) is fundamental for managing craniosynostosis, Asian norms in this regard are unknown. The purpose of this study was to establish a growth curve for ICVs in a large series of normal Asian children, providing reference values to guide corrective surgery. METHODS: A total of 124 normal children (male, 63; female, 61) and 41 children diagnosed with craniosynostoses were analyzed. Patients aged 0-8 years presenting to the emergency room and subjected to computed tomography (CT) for head trauma served as the reference cohort...
September 21, 2017: Journal of Cranio-maxillo-facial Surgery
https://www.readbyqxmd.com/read/28971028/computed-tomography-pattern-of-traumatic-head-injury-in-niger-delta-nigeria-a-multicenter-evaluation
#9
Chinwe Regina Onwuchekwa, Nengi S Alazigha
BACKGROUND AND PURPOSE: Traumatic head injury has a high mortality and morbidity in low- and middle-income countries. Brain injury following trauma is the cause of death in about one-third of patients that die after trauma. The aim of the study was to assess the pattern of computed tomography (CT) findings in head trauma at the tertiary health institutions serving the Niger Delta region of Nigeria. PATIENTS AND METHODS: The CT scans of the head of 310 consecutive patients referred specifically for evaluation of head injury were prospectively reviewed...
July 2017: International Journal of Critical Illness and Injury Science
https://www.readbyqxmd.com/read/28964205/improved-scatter-correction-with-factor-analysis-for-planar-and-spect-imaging
#10
Peter Knoll, Arman Rahmim, Selma Gültekin, Martin Šámal, Michael Ljungberg, Siroos Mirzaei, Paul Segars, Boguslaw Szczupak
Quantitative nuclear medicine imaging is an increasingly important frontier. In order to achieve quantitative imaging, various interactions of photons with matter have to be modeled and compensated. Although correction for photon attenuation has been addressed by including x-ray CT scans (accurate), correction for Compton scatter remains an open issue. The inclusion of scattered photons within the energy window used for planar or SPECT data acquisition decreases the contrast of the image. While a number of methods for scatter correction have been proposed in the past, in this work, we propose and assess a novel, user-independent framework applying factor analysis (FA)...
September 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28958650/is-routine-head-ct-indicated-in-awake-stable-older-patients-after-a-ground-level-fall
#11
Rebecca Sartin, Christine Kim, Sharmila Dissanaike
BACKGROUND: Despite the development of several prediction rules to guide head CT imaging, determining whom to screen for head trauma in the geriatric population after a ground level fall remains controversial. The purpose of this study was to assess the impact of head CT on the management of older adult patients who present with a normal GCS after a ground level fall, and to identify factors that could predict the need for neurosurgical intervention. METHODS: A retrospective study was conducted on hemodynamically stable patients >55 years of age with GCS of 15, who presented to a level 1 trauma center after a ground level fall...
September 18, 2017: American Journal of Surgery
https://www.readbyqxmd.com/read/28952463/a-monte-carlo-study-of-organ-and-effective-doses-of-cone-beam-computed-tomography-cbct-scans-in-radiotherapy
#12
Abdullah Abuhaimed, Colin J Martin, Marimuthu Sankaralingam
Cone-beam CT (CBCT) scans utilized for image guided radiation therapy (IGRT) procedures have become an essential part of radiotherapy. The aim of this study was to assess organ and effective doses resulting from new CBCT scan protocols (head, thorax, and pelvis) released with a software upgrade of the kV on-board-imager (OBI) system. Influence of the scan parameters that were changed in the new protocols on the patient dose was also investigated. Organ and effective doses for protocols of the new software (V2...
September 27, 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/28951948/a-comparison-study-of-size-specific-dose-estimate-calculation-methods
#13
Roshni A Parikh, Michael A Wien, Ronald D Novak, David W Jordan, Paul Klahr, Stephanie Soriano, Leslie Ciancibello, Sheila C Berlin
BACKGROUND: The size-specific dose estimate (SSDE) has emerged as an improved metric for use by medical physicists and radiologists for estimating individual patient dose. Several methods of calculating SSDE have been described, ranging from patient thickness or attenuation-based (automated and manual) measurements to weight-based techniques. OBJECTIVE: To compare the accuracy of thickness vs. weight measurement of body size to allow for the calculation of the size-specific dose estimate (SSDE) in pediatric body CT...
September 27, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28951792/asymptomatic-pancreatic-metastasis-from-renal-cell-carcinoma-diagnosed-21-years-after-nephrectomy
#14
Megumi Zianne, Naoki Takahashi, Akihiko Tsujibata, Kazuhiro Miwa, Yoshinori Goto, Yutaka Matano
This report presents our experience with a case of pancreatic metastasis of renal cell carcinoma (RCC) at a long-term follow-up after nephrectomy. A 73-year-old man underwent nephrectomy for right RCC 21 years ago; computed tomography (CT) scanning on routine follow-up revealed a solid mass in the tail of the pancreas, and magnetic resonance imaging (MRI) showed some tumors in the head and tail of the pancreas. The patient was asymptomatic and allergic to contrast medium. Therefore we could not perform contrast CT/MRI for further examination to diagnose pancreatic tumors...
2017: Case Reports in Gastrointestinal Medicine
https://www.readbyqxmd.com/read/28950737/hyper-attenuating-brain-lesions-on-ct-after-ischemic-stroke-and-thrombectomy-are-associated-with-final-brain-infarction
#15
F B Cabral, L H Castro-Afonso, G S Nakiri, L M Monsignore, Src Fábio, A C Dos Santos, O M Pontes-Neto, D G Abud
Purpose Hyper-attenuating lesions, or contrast staining, on a non-contrast brain computed tomography (NCCT) scan have been investigated as a predictor for hemorrhagic transformation after endovascular treatment of acute ischemic stroke (AIS). However, the association of hyper-attenuating lesions and final ischemic areas are poorly investigated in this setting. The aim of the present study was to assess correlations between hyper-attenuating lesions and final brain infarcted areas after thrombectomy for AIS...
January 1, 2017: Interventional Neuroradiology
https://www.readbyqxmd.com/read/28942415/confusion-and-abdominal-symptoms-following-a-rugby-tackle
#16
Demetris Ioannides, Madeleine Davies, Stefan Kluzek
A 19-year-old man was sent to the emergency department following a pitch-side assessment for suspected concussion, unexplained upper abdominal tenderness and vomiting, following a high-impact tackle during a rugby match. A Focussed Assessment with Sonography for Trauma (FAST) scan performed in the emergency department suggested intra-abdominal free fluid, and subsequent head and abdominal CT imaging showed no intracranial lesion but confirmed a significant haemoperitoneum due to large splenic tear and bleeding...
September 23, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28934810/cross-sectional-imaging-of-solitary-lesions-of-the-neurocranium
#17
Max-Ludwig Schäfer, Arend Koch, Florian Streitparth, Edzard Wiener
Background Although a wide range of processes along the neurocranium are of a benign nature, there are often difficulties in the differential diagnosis. Method In the review CT/MRI scans of the head were evaluated retrospectively regarding solitary lesions along the neurocranium. The majority of the lesions were histologically proven. Results The purpose of the review is to present typical pathologies of the neurocranium and provide a systematic overview based on 12 entities, their locations, prevalence and radiological characteristics...
September 21, 2017: RöFo: Fortschritte Auf Dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
https://www.readbyqxmd.com/read/28930942/surgical-residents-interpretation-of-diagnostic-radiologic-imaging-in-the-traumatically-injured-patient
#18
Elias Fakhoury, Daria Abolghasemi, Justin McKinney, Alena Naumova, Scott Wessner, Osama Elsawy, Jamshed Zuberi, Robert V Madlinger
BACKGROUND: Senior surgical residents are of paramount importance in directing further therapeutic modalities based on their interpretation of critical diagnostic imaging. We propose that senior surgical residents are proficient with interpreting radiologic imaging studies in the trauma patient. METHODS: A prospective cohort study was performed comparing surgery resident interpretations of computerized tomography (CT) scans of the head, maxillofacial bones, spine (cervical, thoracic, lumbar), chest, abdomen, pelvis, and chest X-rays versus final radiologists' reports at a level II trauma center from September 2014 to May 2015...
September 20, 2017: Journal of Trauma and Acute Care Surgery
https://www.readbyqxmd.com/read/28929063/lymph-node-central-necrosis-on-the-computed-tomography-as-the-predictor-of-the-extra-capsular-spread-in-metastatic-head-and-neck-squamous-cell-carcinoma
#19
Aditi Sharma, Ashwin Ashok Jaiswal, Girish Umredkar, Ratiram Barle, Neeta Sharma, Praveer Kumar Banerjee, Amrish Kumar Garg, Ravindranath Membally
The aim of this study is to investigate the relationship between the presence of the cervical lymph node with central necrosis as on the preoperative imaging and postoperative histopathological identification of the lymph node extra capsular spread. This study is a prospective study conducted at J.L.N. Hospital and Research Centre, Bhilai (C.G), from August 2011 to January 2014. Thirty patients with metastatic head and neck squamous cell carcinoma were enrolled. All candidates were subjected to a detailed history taking and clinical examination...
September 2017: Indian Journal of Otolaryngology and Head and Neck Surgery
https://www.readbyqxmd.com/read/28926370/photon-counting-computed-tomography-for-vascular-imaging-of-the-head-and-neck-first-in-vivo-human-results
#20
Rolf Symons, Daniel S Reich, Mohammadhadi Bagheri, Tyler E Cork, Bernhard Krauss, Stefan Ulzheimer, Steffen Kappler, David A Bluemke, Amir Pourmorteza
PURPOSE: The purpose of this study was to evaluate image quality of a spectral photon-counting detector (PCD) computed tomography (CT) system for evaluation of major arteries of the head and neck compared with conventional single-energy CT scans using energy-integrating detectors (EIDs). METHODS: In this institutional review board-approved study, 16 asymptomatic subjects (7 men) provided informed consent and received both PCD and EID contrast-enhanced CT scans of the head and neck (mean age, 58 years; range, 46-75 years)...
September 18, 2017: Investigative Radiology
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