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https://www.readbyqxmd.com/read/28918316/mr-guided-joint-reconstruction-of-activity-and-attenuation-in-brain-pet-mr
#1
Abolfazl Mehranian, Habib Zaidi, Andrew J Reader
With the advent of time-of-flight (TOF) PET scanners, joint maximum-likelihood reconstruction of activity and attenuation (MLAA) maps has recently regained attention for the estimation of PET attenuation maps from emission data. However, the estimated attenuation and activity maps are scaled by unknown scaling factors. We recently demonstrated that in hybrid PET-MR, the scaling issue of this algorithm can be effectively addressed by imposing MR spatial constraints on the estimation of attenuation maps using a penalized MLAA (P-MLAA(+)) algorithm...
September 13, 2017: NeuroImage
https://www.readbyqxmd.com/read/28918063/a-pca-based-method-for-determining-craniofacial-relationship-and-sexual-dimorphism-of-facial-shapes
#2
Wuyang Shui, Mingquan Zhou, Steve Maddock, Taiping He, Xingce Wang, Qingqiong Deng
Previous studies have used principal component analysis (PCA) to investigate the craniofacial relationship, as well as sex determination using facial factors. However, few studies have investigated the extent to which the choice of principal components (PCs) affects the analysis of craniofacial relationship and sexual dimorphism. In this paper, we propose a PCA-based method for visual and quantitative analysis, using 140 samples of 3D heads (70 male and 70 female), produced from computed tomography (CT) images...
September 7, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28901782/a-radiographic-dye-method-for-intraoperative-evaluation-of-syndesmotic-injuries
#3
Murad Pepe, Onur Kocadal, Zafer Gunes, Emre Calisal, Kubilay Ceritoglu, Cem Nuri Aktekin
BACKGROUND: The Chertsey test has been recently defined as an intraoperative test for the detection of the syndesmotic injuries by the application of intra-articular contrast. However, no study has investigated the reliability and comparative analysis of the Chertsey test. The purpose of this study was to explore the diagnostic accuracy of the Chertsey test in predicting syndesmosis instability of the injured ankle, with correlation to preoperative computed tomography (CT) findings. METHODS: A total of 39 patients who were operated on due to the unilateral ankle fracture and had no complaint on the contralateral ankle joint were included in the study...
September 1, 2017: Foot & Ankle International
https://www.readbyqxmd.com/read/28901573/validation-of-a-novel-cartoseg%C3%A2-segmentation-module-software-for-contrast-enhanced-computed-tomography-guided-radiofrequency-ablation-in-patients-with-atrial-fibrillation
#4
EDITORIAL
Hasan Imanli, Shaun Bhatty, Jean Jeudy, Yousra Ghzally, Kiddy Ume, Rama Vunnam, Refael Itah, Mati Amit, John Duell, Vincent See, Stephen Shorofsky, Timm M Dickfeld
INTRODUCTION: Visualization of left atrial (LA) anatomy using image integration modules has been associated with decreased radiation exposure and improved procedural outcome when used for guidance of pulmonary vein isolation (PVI) in atrial fibrillation (AF) ablation. We evaluated the CARTOSEG™ CT Segmentation Module (Biosense Webster, Inc.) that offers a new CT-specific semi-automatic reconstruction of the atrial endocardium. METHODS: The CARTOSEG™ CT Segmentation Module software was assessed prospectively in 80 patients undergoing AF ablation...
September 13, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28901055/phantom-based-image-quality-test-methods-for-photoacoustic-imaging-systems
#5
William C Vogt, Congxian Jia, Keith A Wear, Brian S Garra, T Joshua Pfefer
As photoacoustic imaging (PAI) technologies advance and applications arise, there is increasing need for standardized approaches to provide objective, quantitative performance assessment at various stages of the product development and clinical translation process. We have developed a set of performance test methods for PAI systems based on breast-mimicking tissue phantoms containing embedded inclusions. Performance standards for mature imaging modalities [magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound] were used to guide selection of critical PAI image quality characteristics and experimental methods...
September 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28898423/iterative-volume-of-interest-based-4d-cone-beam-ct
#6
Rachael Martin, Moiz Ahmad, Geoffrey Hugo, Tinsu Pan
PURPOSE: 4D cone-beam CT (CBCT) has potential applications in soft tissue alignment and tumor motion verification at the time of radiation treatment. However, prominent streak artifacts with conventional image reconstructions have limited its clinical use and alternative reconstructions are generally too computationally expensive for the time available. We propose an iterative volume of interest based (I4D VOI) reconstruction technique, where 4D reconstruction is only performed within a VOI, to limit streak artifacts with limited added computation time...
September 12, 2017: Medical Physics
https://www.readbyqxmd.com/read/28875364/age-and-sex-based-resource-utilisation-and-costs-in-patients-with-acute-chest-pain-undergoing-cardiac-ct-angiography-pooled-evidence-from-romicat-ii-and-acrin-pa-trials
#7
Fabian Bamberg, Thomas Mayrhofer, Maros Ferencik, Daniel O Bittner, Travis R Hallett, Sumbal Janjua, Christopher L Schlett, John T Nagurney, James E Udelson, Quynh A Truong, Pamela K Woodard, Judd E Hollander, Harold Litt, Udo Hoffmann
OBJECTIVES: To determine resource utilisation according to age and gender-specific subgroups in two large randomized diagnostic trials. METHODS: We pooled patient-specific data from ACRIN-PA 4005 and ROMICAT II that enrolled subjects with acute chest pain at 14 US sites. Subjects were randomized between a standard work-up and a pathway utilizing cardiac computed tomography angiography (CCTA) and followed for the occurrence of acute coronary syndrome (ACS) and resource utilisation during index hospitalisation and 1-month follow-up...
September 5, 2017: European Radiology
https://www.readbyqxmd.com/read/28872442/added-value-of-computer-aided-ct-image-features-for-early-lung-cancer-diagnosis-with-small-pulmonary-nodules-a-matched-case-control-study
#8
Peng Huang, Seyoun Park, Rongkai Yan, Junghoon Lee, Linda C Chu, Cheng T Lin, Amira Hussien, Joshua Rathmell, Brett Thomas, Chen Chen, Russell Hales, David S Ettinger, Malcolm Brock, Ping Hu, Elliot K Fishman, Edward Gabrielson, Stephen Lam
Purpose To test whether computer-aided diagnosis (CAD) approaches can increase the positive predictive value (PPV) and reduce the false-positive rate in lung cancer screening for small nodules compared with human reading by thoracic radiologists. Materials and Methods A matched case-control sample of low-dose computed tomography (CT) studies in 186 participants with 4-20-mm noncalcified lung nodules who underwent biopsy in the National Lung Screening Trial (NLST) was selected. Variables used for matching were age, sex, smoking status, chronic obstructive pulmonary disease status, body mass index, study year of the positive screening test, and screening results...
September 5, 2017: Radiology
https://www.readbyqxmd.com/read/28866897/superior-target-delineation-for-stereotactic-body-radiotherapy-of-bone-metastases-from-renal-cell-carcinoma-on-mri-compared-to-ct
#9
Fieke M Prins, Joanne M van der Velden, Anne S Gerlich, Alexis N T J Kotte, Wietse S C Eppinga, Nicolien Kasperts, Jorrit J Verlaan, Frank A Pameijer, Linda G W Kerkmeijer
BACKGROUND: In metastatic renal cell carcinoma (mRCC) there has been a treatment shift towards targeted therapy, which has resulted in improved overall survival. Therefore, there is a need for better local control of the tumor and its metastases. Image-guided stereotactic body radiotherapy (SBRT) in bone metastases provides improved symptom palliation and local control. With the use of SBRT there is a need for accurate target delineation. The hypothesis is that MRI allows for better visualization of the extend of bone metastases in mRCC and will optimize the accuracy of tumor delineation for stereotactic radiotherapy purposes, compared with CT only...
July 11, 2017: Annals of Palliative Medicine
https://www.readbyqxmd.com/read/28854069/fluorodeoxyglucose-positron-emission-tomography-computed-tomography-after-concurrent-chemoradiotherapy-in-locally-advanced-head-and-neck-squamous-cell-cancer-the-eclyps-study
#10
Tim Van den Wyngaert, Nils Helsen, Laurens Carp, Sara Hakim, Michel J Martens, Isabel Hutsebaut, Philip R Debruyne, Annelies L M Maes, Joost van Dinther, Carl G Van Laer, Otto S Hoekstra, Remco De Bree, Sabine A E Meersschout, Olivier Lenssen, Jan B Vermorken, Danielle Van den Weyngaert, Sigrid Stroobants
Purpose To assess the standardized implementation and reporting of surveillance [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scan of the neck in locoregionally advanced head-and-neck squamous cell carcinoma (LAHNSCC) after concurrent chemoradiotherapy (CCRT). Patients and Methods We performed a prospective multicenter study of FDG-PET/CT scanning 12 weeks after CCRT in newly diagnosed patients with LAHNSCC (stage IVa/b) that used standardized reconstruction and Hopkins reporting criteria...
August 30, 2017: Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology
https://www.readbyqxmd.com/read/28838020/-the-relevance-of-surgeon-performed-ultrasound-for-the-detection-of-acute-appendicitis-a-review-of-the-literature-and-a-practical-diagnostic-algorithm
#11
Christian Rainer Beltzer, Christoph Zischek, Roland Schmidt, Benedikt Friemert, Gerhard Achatz, Hans-Georg Palm
Background The relevance of ultrasound (US) in diagnosing acute appendicitis is controversial. The validity of US in comparison with other imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), is unclear, as is the difference between surgeon-performed ultrasound (SPUS) and radiologist-performed ultrasound (RPUS). On the basis of a review of current literature, our study aimed to develop a US-based algorithm to simplify the choice between additional diagnostic measures and surgery...
August 2017: Zentralblatt Für Chirurgie
https://www.readbyqxmd.com/read/28837044/estimation-of-lung-shunt-fraction-from-simultaneous-fluoroscopic-and-nuclear-images
#12
Sandra van der Velden, Remco Bastiaannet, Arthur J A T Braat, Marnix G E H Lam, Max A Viergever, Hugo W A M de Jong
Radioembolisation with yttrium-90 (<sup>90</sup>Y) is increasingly used as a treatment of unresectable liver malignancies. For safety, a scout dose of technetium-99m macroaggregated albumin (<sup>99m</sup>Tc-MAA) is used prior to the delivery of the therapeutic activity to mimic the deposition of <sup>90</sup>Y. One-day procedures are currently limited by the lack of nuclear images in the intervention room. To cope with this limitation, an interventional simultaneous fluoroscopic and nuclear imaging device is currently being developed...
August 24, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28828589/diagnostic-and-prognostic-value-of-18f-fdg-pet-ct-in-recurrent-germinal-tumor-carcinoma
#13
Pierpaolo Alongi, Laura Evangelista, Federico Caobelli, Marianna Spallino, Luigi Gianolli, Massimo Midiri, Maria Picchio
AIM: The aim of this bicentric retrospective study was to assess the diagnostic performance, the prognostic value, the incremental prognostic value and the impact on therapeutic management of (18)F-FDG PET/CT in patients with suspected recurrent germinal cell testicular carcinoma (GCT). MATERIALS AND METHODS: From the databases of two centers including 31,500 (18)F-FDG PET/CT oncological studies, 114 patients affected by GCT were evaluated in a retrospective study...
August 22, 2017: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/28825917/evaluation-of-an-automatic-mr-based-gold-fiducial-marker-localisation-method-for-mr-only-prostate-radiotherapy
#14
Matteo Maspero, Cornelis A T Van den Berg, Frank Zijlstra, Gonda G Sikkes, Hans C J de Boer, Gert J Meijer, Linda G W Kerkmeijer, Max A Viergever, Jan J W Lagendijk, Peter R Seevinck
An MR-only radiotherapy planning (RTP) workflow would reduce cost, radiation exposure and uncertainties introduced by CT-MRI registrations. In the case of prostate treatment, one of the remaining challenges currently withholding implementation of an RTP workflow is the MR-based localisation of intraprostatic gold Fiducial Markers (FMs), which is crucial for accurate patient positioning. Currently, MR-based FM localisation is clinically performed manually. This is sub-optimal as manual interaction increases workload...
August 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28822820/utility-of-3d-reconstruction-of-2d-liver-computed-tomography-magnetic-resonance-images-as-a-surgical-planning-tool-for-residents-in-liver-resection-surgery
#15
Caitlin T Yeo, Andrew MacDonald, Tamas Ungi, Andras Lasso, Diederick Jalink, Boris Zevin, Gabor Fichtinger, Sulaiman Nanji
OBJECTIVE: A fundamental aspect of surgical planning in liver resections is the identification of key vessel tributaries to preserve healthy liver tissue while fully resecting the tumor(s). Current surgical planning relies primarily on the surgeon's ability to mentally reconstruct 2D computed tomography/magnetic resonance (CT/MR) images into 3D and plan resection margins. This creates significant cognitive load, especially for trainees, as it relies on image interpretation, anatomical and surgical knowledge, experience, and spatial sense...
August 16, 2017: Journal of Surgical Education
https://www.readbyqxmd.com/read/28813561/comparison-of-coronary-ct-angiography-spect-pet-and-hybrid-imaging-for-diagnosis-of-ischemic-heart-disease-determined-by-fractional-flow-reserve
#16
Ibrahim Danad, Pieter G Raijmakers, Roel S Driessen, Jonathon Leipsic, Rekha Raju, Chris Naoum, Juhani Knuuti, Maija Mäki, Richard S Underwood, James K Min, Kimberly Elmore, Wynand J Stuijfzand, Niels van Royen, Igor I Tulevski, Aernout G Somsen, Marc C Huisman, Arthur A van Lingen, Martijn W Heymans, Peter M van de Ven, Cornelis van Kuijk, Adriaan A Lammertsma, Albert C van Rossum, Paul Knaapen
Importance: At present, the choice of noninvasive testing for a diagnosis of significant coronary artery disease (CAD) is ambiguous, but nuclear myocardial perfusion imaging with single-photon emission tomography (SPECT) or positron emission tomography (PET) and coronary computed tomography angiography (CCTA) is predominantly used for this purpose. However, to date, prospective head-to-head studies are lacking regarding the diagnostic accuracy of these imaging modalities. Furthermore, the combination of anatomical and functional assessments configuring a hybrid approach may yield improved accuracy...
August 16, 2017: JAMA Cardiology
https://www.readbyqxmd.com/read/28810259/reliability-reproducibility-and-prognostic-accuracy-of-the-alberta-stroke-program-early-ct-score-on-ct-perfusion-and-non-contrast-ct-in-hyperacute-stroke
#17
Jillian Naylor, Leonid Churilov, Ziyuan Chen, Miriam Koome, Neil Rane, Bruce C V Campbell
BACKGROUND: Alberta Stroke Program Early CT Score (ASPECTS) assesses early ischemic change on non-contrast CT (NCCT). We hypothesised that assessing ASPECTS regions on CT Perfusion (CTP) rather than NCCT would improve inter-rater agreement and prognostic accuracy, particularly in patients presenting early after stroke onset. METHODS: Ischemic stroke patients treated with intravenous alteplase from 2009 to 2014 at our institution were included in this study. Inter-rater agreement and prognostic accuracy of ASPECTS across modalities were analysed by the time between stroke onset and initial NCCT, dichotomized 1st quartile versus quartiles 2-4, referred to as epochs...
August 16, 2017: Cerebrovascular Diseases
https://www.readbyqxmd.com/read/28807441/whole-body-dose-and-energy-measurements-in-radiotherapy-by-a-combination-of-lif-mg-cu-p-and-lif-mg-ti
#18
Pascal Hauri, Uwe Schneider
PURPOSE: Long-term survivors of cancer who were treated with radiotherapy are at risk of a radiation-induced tumor. Hence, it is important to model the out-of-field dose resulting from a cancer treatment. These models have to be verified with measurements, due to the small size, the high sensitivity to ionizing radiation and the tissue-equivalent composition, LiF thermoluminescence dosimeters (TLD) are well-suited for out-of-field dose measurements. However, the photon energy variation of the stray dose leads to systematic dose errors caused by the variation in response with radiation energy of the TLDs...
August 11, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28803447/registration-free-automatic-identification-of-gold-fiducial-markers-in-mri-target-delineation-images-for-prostate-radiotherapy
#19
Christian Gustafsson, Juha Korhonen, Emilia Persson, Adalsteinn Gunnlaugsson, Tufve Nyholm, Lars E Olsson
PURPOSE: The superior soft tissue contrast of magnetic resonance imaging (MRI) compared to computed tomography (CT) has urged the integration of MRI and elimination of CT in radiotherapy treatment (RT) for prostate. An intraprostatic gold fiducial marker (GFM) appear hyperintense on CT. On T2 weighted (T2w) MRI target delineation images the GFM appear as a small signal void similar to calcifications and post biopsy fibrosis. It can therefore be difficult to identify the markers without CT...
August 13, 2017: Medical Physics
https://www.readbyqxmd.com/read/28803217/accurate-model-based-segmentation-of-gynecologic-brachytherapy-catheter-collections-in-mri-images
#20
Andre Mastmeyer, Guillaume Pernelle, Ruibin Ma, Lauren Barber, Tina Kapur
The gynecological cancer mortality rate, including cervical, ovarian, vaginal and vulvar cancers, is more than 20,000 annually in the US alone. In many countries, including the US, external-beam radiotherapy followed by high dose rate brachytherapy is the standard-of-care. The superior ability of MR to visualize soft tissue has led to an increase in its usage in planning and delivering brachytherapy treatment. A technical challenge associated with the use of MRI imaging for brachytherapy, in contrast to that of CT imaging, is the visualization of catheters that are used to place radiation sources into cancerous tissue...
July 18, 2017: Medical Image Analysis
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