نتایج جستجو برای: phantom ct ct number
تعداد نتایج: 1305532 فیلتر نتایج به سال:
Introduction: The present study is aimed to design and develop a tissue-equivalent pelvic phantom, mimicking the Indian female pelvic dimensions by means of locally available and cost-effective tissue substitutes having equivalent radiological properties. Materials and Methods: For the purpose of the study, the real female pelvic bones were embedded for preparation. Paraffin wax, Aloe-vera powd...
In present PET/CT scanners, PET attenuation correction is performed by relying on the information given by CT scan. In the CT-based attenuation correction methods, dual-energy technique (DECT) is the most accurate approach, which has been limited due to the increasing patient dose. In this feasibility study, we have introduced a new method that can implement dual-energy technique with only a si...
Computed Tomography (CT) and Magnetic Resonance (MR) imaging techniques have become an important role in diagnosing the vascular diseases. Before a clinical trial of the newly developed techniques, it is essential to evaluate them on a phantom. However, there is no existing arterial A Dynamic Arterial Tree Phantom for studies 89 tree phantom that serves for flood flows. To that end, we design a...
Radiotherapy treatment planning integrating positron emission tomography (PET) and computerized tomography (CT) is rapidly gaining acceptance in the clinical setting. Although hybrid systems are available, often the planning CT is acquired on a dedicated system separate from the PET scanner. A limiting factor to using PET data becomes the accuracy of the CT/PET registration. In this work, we us...
This paper aims to evaluate the impact of spectral filtration on image quality in a microcomputed tomography (micro-CT) system. A mouse phantom comprising 11 rods for modeling lung, muscle, adipose, and bones was scanned with 17 s and 2 min, respectively. The current (μA) for each scan was adjusted to achieve identical entrance exposure to the phantom, providing a baseline for image quality eva...
OBJECTIVE To evaluate whether there is a relationship between subjective parameters determined by a reviewer (spatial resolution, low contrast resolution, and artifacts) and objective parameters (the CT number of water, noise, and image uniformity) in CT phantom image evaluations. MATERIALS AND METHODS We reviewed the CT results of phantom image evaluations conducted by Korean Institute for A...
A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume ef...
The image quality (IQ) of imaging systems must be sufficiently high for image-guided radiation therapy (IGRT). Hence, users should implement a quality assurance program to maintain IQ. In our routine IQ tests of the kV cone-beam CT system (Elekta XVI), image noise was quantified by noise standard deviation (NSD), which was the standard deviation of CT numbers measured in a small area in an imag...
OBJECTIVES The aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in (123)I brain SPECT obtained by the hybrid SPECT/CT device. METHODS We used the 3-dimensional (3D) brain phantom, which imitates the precise structure of gray matter, white matter and bone regions. It was filled with (123)I soluti...
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