نتایج جستجو برای: respiratory motion

تعداد نتایج: 416200  

2016
Benjamin M.W. Tsui Tao Feng Jizhe Wang Jingyan Xu M. Roselle Abraham Stefan L. Zimmerman Thomas H. Schindler

Quantitative four-dimensional (4D) image reconstruction methods with respiratory and cardiac motion compensation are an active area of research in ECT imaging, including SPECT and PET. They are the extensions of three-dimensional (3D) statistical image reconstruction methods with iterative algorithms that incorporate accurate models of the imaging process and provide significant improvement in ...

2016
Davide Piccini Li Feng Gabriele Bonanno Simone Coppo Jérôme Yerly Ruth P Lim Juerg Schwitter Daniel K Sodickson Ricardo Otazo Matthias Stuber

Background Navigator gating is commonly used to minimize respiratory motion in free-breathing whole-heart coronary MRA [1]. However, lengthy and unpredictable acquisition times remain a drawback. Respiratory self-navigation (SN) [2-3], conversely, enables 100% scan efficiency, but performs motion correction over a broad range of respiratory displacements, which can result in image artifacts. He...

2015
Hadi Fayad Florian Monnier Freedy Odille Jacques Felblinger Frederic Lamare Dimitris Visvikis

LaTIM, INSERM, UMR 1101, Brest, France Respiratory and cardiac motion in PET/MR imaging leads to reduced quantitative and qualitative image accuracy. Correction methodologies involve the use of double gated acquisitions which lead to low signal-to-noise ratio (SNR) and to issues concerning the combination of cardiac and respiratory frames. The objective of this work is to use a generalized reco...

2013
Ashrani Aizzuddin Abd. Rahni Emma Lewis Kevin Wells

Compensation for respiratory motion has been identified as a crucial factor in achieving high resolution Nuclear Medicine (NM) imaging. Many motion correction approaches have been studied and they are seen to have advantages over simpler approaches such as respiratory gating. However, all motion correction approaches rely on an assumption or estimation of respiratory motion. This paper builds u...

Ahmad Bitarafan rajabi, Khadijeh Bamneshin Parham Geramifar Seied Mohsen Shahabi Seied Rabi Mahdavi,

Introduction: To investigate the effects of breathing cycle and tree diaphragm motions on prostate cancer tumors standard uptake value (SUV) during positron emission tomography (PET) and to correct it. Materials and methods: Respiratory motion traces were simulated on the common patient breathing cycle and tree diaphragm motio...

Background: Respiratory motion causes thoracic movement and reduces targeting accuracy in radiotherapy. Objective: This study proposes an approach to generate a model to track lung tumor motion by controlling dynamic multi-leaf collimators. Material and Methods: All slices which contained tumor were contoured in the 4D-CT images for...

2013
Ashrani Aizzuddin Abd. Rahni Emma Lewis Kevin Wells

Nuclear Medicine (NM) imaging is currently the most sensitive approach for functional imaging of the human body. However, in order to achieve high-resolution imaging, one of the factors degrading the detail or apparent resolution in the reconstructed image, namely respiratory motion, has to be overcome. All respiratory motion correction approaches depend on some assumption or estimate of respir...

2013
Joseph Y. Cheng Tao Zhang John M. Pauly Shreyas S. Vasanawala Michael Lustig

PURPOSE: Respiratory motion is a major issue in abdominal MRI, especially for pediatric patients who have difficulty performing breath-holds. The problem is exacerbated in lengthy scans, such as for dynamic contrast enhanced (DCE) MRI. Much of the previous work has been focused on reducing respiratory motion artifacts through reconstruction correction schemes. An alternative approach is resolvi...

Daryoush Shahbazi-Gahrouei, Milad Baradaran-Ghahfarokhi Mohammad Amin Mosleh-Shirazi, Nader Fallahian Sadegh Sherkat Zahra Akmali

Introduction: In radiation therapy, determining the location of the tumor accurately during irradiation is one of the most important requirements. However, lung tumors are not fixed in a single location and move during irradiation due to respiratory motion. Due to limitations in assessing such movements, using a lung phantom can be useful and operational for their fast, easy an...

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