نتایج جستجو برای: respiratory motion

تعداد نتایج: 416200  

Journal: :iranian journal of nuclear medicine 2007
kourosh ebrahim nejad gorgi hossein rajabi ebrahim hajizadeh faraz kalantari hadi taleshi

introduction: there are several technical features that make pet an ideal device for the noninvasive evaluation of cardiac physiology. organ motion due to respiration is a major challenge in diagnostic imaging, especially in cardiac pet imaging. these motions reduce image quality by spreading the radiotracer activity over an increased volume, distorting apparent lesion size and shape and reduci...

Journal: :iranian journal of radiation research 0
r. chang-li cancer center, renmin hospital of wuhan university, wuhan 430060, china c. yu-xin cancer center, renmin hospital of wuhan university, wuhan 430060, china w. lu-zhou cancer center, renmin hospital of wuhan university, wuhan 430060, china wu-bing cancer center, renmin hospital of wuhan university, wuhan 430060, china s. qi-bin cancer center, renmin hospital of wuhan university, wuhan 430060, china

background: 3dcrt (three-dimensional conformal radiotherapy) and imrt (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. however, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. the purpose of this study is to evaluate the imp...

WU-bing, C. Yu-xin, R. Chang-li, S. Qi-bin, W. Lu-zhou,

Background: 3DCRT (three-dimensional conformal radiotherapy) and IMRT (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. However, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. The purpose of this study is to evaluate the imp...

Journal: :iranian journal of nuclear medicine 2005
arman rahmim

with the arrival of increasingly higher resolution pet systems, small amounts of motion can cause significant blurring in the images, compared to the intrinsic resolutions of the scanners. in this work, we have reviewed advanced correction methods for the three cases of (i) unwanted patient motion, as well as motions due to (ii) cardiac and (iii) respiratory cycles. for the first type of motion...

Arman Rahmim

With the arrival of increasingly higher resolution PET systems, small amounts of motion can cause significant blurring in the images, compared to the intrinsic resolutions of the scanners. In this work, we have reviewed advanced correction methods for the three cases of (i) unwanted patient motion, as well as motions due to (ii) cardiac and (iii) respiratory cycles. For the first type of ...

Journal: :iranian journal of radiation research 0
h. w. zhang department of radiotherapy; jiang-xi cancer hospital; nanchang 330029, china y. l. wang department of radiation oncology, pla general hospital, beijing 100853, china y. l. wang department of radiation oncology, pla general hospital, beijing 100853, china

background: a method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement. materials and methods: the method was based on the following idea: (i) before treatment, a series of fluoroscopic images corresponding to different bre...

B. Hu, H. W. Zhang, Y. L. Wang,

Background: A method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement. Materials and Methods: The method was based on the following idea: (i) Before treatment, a series of fluoroscopic images corresponding to different bre...

Journal: :iranian journal of radiation research 0
a. esmaili torshabi medical physics group, department of electrical and computer engineering, graduate university of advanced technology, haftbagh st. 7631133131, kerman, iran

background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...

Journal: :journal of biomedical physics and engineering 0
s parande a esmaili torshabi

background: medical image interpolation is recently introduced as a helpful tool to obtain further information via initial available images taken by tomography systems. this information may be useful for better diagnosis of possible lesions or better tumor delineation at radiation treatment. to do this, deformable image registration algorithms are mainly utilized to perform image interpolation ...

Ebrahim Hajizadeh Faraz Kalantari, Hadi Taleshi Hossein Rajabi, Kourosh Ebrahim Nejad Gorgi

  Introduction: There are several technical features that make PET an ideal device for the noninvasive evaluation of cardiac physiology. Organ motion due to respiration is a major challenge in diagnostic imaging, especially in cardiac PET imaging. These motions reduce image quality by spreading the radiotracer activity over an increased volume, distorting apparent les...

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