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Title: Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy

Abstract

Purpose: Four-dimensional cone-beam computed tomography (4D-CBCT) imaging is sensitive to parameters such as gantry rotation speed, number of gantry rotations, X-ray pulse rate, and tube current, as well as a patient's breathing pattern. The aim of this study is to optimize the image acquisition on a patient-specific basis while minimizing the scan time and the radiation dose. Methods and Materials: More than 60 sets of 4D-CBCT images, each with a temporal resolution of 10 phases, were acquired using multiple-gantry rotation and slow-gantry rotation techniques. The image quality was quantified with a relative root mean-square error (RE) and correlated with various acquisition settings; specifically, varying gantry rotation speed, varying both the rotation speed and the number of rotations, and varying both the rotation speed and tube current to keep the radiation exposure constant. These experiments were repeated for three different respiratory periods. Results: With similar radiation dose, 4D-CBCT images acquired with low current and low rotation speed have better quality over images obtained with high current and high rotation speed. In general, a one-rotation low-speed scan is superior to a two-rotation double-speed scan, even though they provide the same number of projections. Furthermore, it is found that the image quality behavesmore » monotonically with the relative speed as defined by the gantry rotation speed and the patient respiratory period. Conclusions: The RE curves established in this work can be used to predict the 4D-CBCT image quality before a scan. This allows the acquisition protocol to be optimized individually to balance the desired quality with the associated scanning time and patient radiation dose.« less

Authors:
 [1];  [2]
  1. Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)
  2. Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States). E-mail: lei@reyes.stanford.edu
Publication Date:
OSTI Identifier:
20944781
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 67; Journal Issue: 4; Other Information: DOI: 10.1016/j.ijrobp.2006.10.024; PII: S0360-3016(06)03338-4; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BEAMS; COMPUTERIZED TOMOGRAPHY; ERRORS; IMAGES; OPTIMIZATION; PATIENTS; RADIATION DOSES; RADIOTHERAPY; RESPIRATION; SPATIAL RESOLUTION; VELOCITY

Citation Formats

Li Tianfang, and Xing Lei. Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy. United States: N. p., 2007. Web.
Li Tianfang, & Xing Lei. Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy. United States.
Li Tianfang, and Xing Lei. Thu . "Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy". United States. doi:.
@article{osti_20944781,
title = {Optimizing 4D cone-beam CT acquisition protocol for external beam radiotherapy},
author = {Li Tianfang and Xing Lei},
abstractNote = {Purpose: Four-dimensional cone-beam computed tomography (4D-CBCT) imaging is sensitive to parameters such as gantry rotation speed, number of gantry rotations, X-ray pulse rate, and tube current, as well as a patient's breathing pattern. The aim of this study is to optimize the image acquisition on a patient-specific basis while minimizing the scan time and the radiation dose. Methods and Materials: More than 60 sets of 4D-CBCT images, each with a temporal resolution of 10 phases, were acquired using multiple-gantry rotation and slow-gantry rotation techniques. The image quality was quantified with a relative root mean-square error (RE) and correlated with various acquisition settings; specifically, varying gantry rotation speed, varying both the rotation speed and the number of rotations, and varying both the rotation speed and tube current to keep the radiation exposure constant. These experiments were repeated for three different respiratory periods. Results: With similar radiation dose, 4D-CBCT images acquired with low current and low rotation speed have better quality over images obtained with high current and high rotation speed. In general, a one-rotation low-speed scan is superior to a two-rotation double-speed scan, even though they provide the same number of projections. Furthermore, it is found that the image quality behaves monotonically with the relative speed as defined by the gantry rotation speed and the patient respiratory period. Conclusions: The RE curves established in this work can be used to predict the 4D-CBCT image quality before a scan. This allows the acquisition protocol to be optimized individually to balance the desired quality with the associated scanning time and patient radiation dose.},
doi = {},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 4,
volume = 67,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}