نتایج جستجو برای: lung motion

تعداد نتایج: 520049  

Journal: :Physics in medicine and biology 2012
Stine S Korreman

This review considers the management of motion in photon radiation therapy. An overview is given of magnitudes and variability of motion of various structures and organs, and how the motion affects images by producing artifacts and blurring. Imaging of motion is described, including 4DCT and 4DPET. Techniques for monitoring motion in real time by use of surrogates are reviewed. Treatment planni...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده ادبیات و زبانهای خارجی 1393

یادگیری فعل و ویژگی های مرتبط با ان همواره یکی از مهم ترین بخش های فراگیری زبان بوده است. افعال حالتی-حرکتی به آن دسته از افعال اطلاق می شودکه حالت وحرکت درآنها ادغام شده است. درزبان انگلیسی مسیر فعل درخود فعل گنجانده می شود (ascend, exit) ولی مسیر فعل درزبان فارسی غالباً توسط حرف اضافه ویا ادات قیدی نشان داده می شود (بیرون رفتن، پایین رفتن). براساس نظرتالمی (1991 ) زبان ها به دو دسته ی ادات محو...

Journal: :The Tokai journal of experimental and clinical medicine 1980
Y Ohta T Yamauchi K Suzuki C Nakamura K Imaoka

A method is described for the simultaneous measurements of three dimensional shifts of the gravitational center of the body caused by ventilatory and cardiac motions. The measuring system consists fundamentally of three load cells which support an aluminum die-casting platform. Measurement of the shift towards the X axis (front-to-back) was achieved by double integration of the outputs of load ...

2016
Charlene S. Stahr Chaminda R. Samarage Martin Donnelley Nigel Farrow Kaye S. Morgan Graeme Zosky Richard C. Boucher Karen K. W. Siu Marcus A. Mall David W. Parsons Stephen Dubsky Andreas Fouras

Computed tomography (CT) and spirometry are the mainstays of clinical pulmonary assessment. Spirometry is effort dependent and only provides a single global measure that is insensitive for regional disease, and as such, poor for capturing the early onset of lung disease, especially patchy disease such as cystic fibrosis lung disease. CT sensitively measures change in structure associated with a...

2015
Romain Brevet Daniel Richter Christian Graeff Marco Durante Christoph Bert

Scanned ion beam therapy of lung tumors is severely limited in its clinical applicability by intrafractional organ motion, interference effects between beam and tumor motion (interplay), as well as interfractional anatomic changes. To compensate for dose deterioration caused by intrafractional motion, motion mitigation techniques, such as gating, have been developed. However, optimization of th...

Journal: :Physics in medicine and biology 2007
Brian Kanagaki Paul W Read Janelle A Molloy James M Larner Ke Sheng

Helical tomotherapy (HT) can potentially be used for lung cancer treatment including stereotactic radiosurgery because of its advanced image guidance and its ability to deliver highly conformal dose distributions. However, previous theoretical and simulation studies reported that the effect of respiratory motion on statically planned tomotherapy treatments may cause substantial differences betw...

2014
Amit Sawant Paul Keall Kim Butts Pauly Marcus Alley Shreyas Vasanawala Billy W Loo Jacob Hinkle Sarang Joshi

Cycle-to-cycle variations in respiratory motion can cause significant geometric and dosimetric errors in the administration of lung cancer radiation therapy. A common limitation of the current strategies for motion management is that they assume a constant, reproducible respiratory cycle. In this work, we investigate the feasibility of using rapid MRI for providing long-term imaging of the thor...

Journal: :Practical radiation oncology 2021

Abstract Purpose Radiation therapy for mesothelioma remains challenging, as normal tissue toxicity limits the amount of radiation that can be safely delivered to pleural surfaces, especially dose contralateral lung. The physical properties proton result in better sparing tissues when treating pleura, both postpneumonectomy setting and lung-intact setting. Compared with photon radiation, there a...

2011
Daniel R. Gomez Joe Y. Chang

The challenges of lung cancer radiotherapy are intra/inter-fraction tumor/organ anatomy/motion changes and the need to spare surrounding critical structures. Evolving radiotherapy technologies, such as four-dimensional (4D) image-based motion management, daily on-board imaging and adaptive radiotherapy based on volumetric images over the course of radiotherapy, have enabled us to deliver higher...

2009
J. Yu Y. Xue H. S. Rad H. Song

Introduction: Conventional gradient-echo based magnetic resonance imaging of lung parenchyma suffers from poor signal-to-noise ratios due to low proton density and short T2* caused by susceptibility gradients between airways and tissue. In addition, respiratory and cardiac motions seriously degrade the achievable image quality. Ultra-short echo time (UTE) MRI has recently gained renewed attenti...

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