نتایج جستجو برای: phantom ct mtf phantom autocad modulation
تعداد نتایج: 300098 فیلتر نتایج به سال:
INTRODUCTION A physical 3-dimensional phantom that simulates PET/SPECT images of static regional cerebral blood flow in grey matter with a realistic head contour has been developed. This study examined the feasibility of using this phantom for evaluating PET/SPECT images. METHODS The phantom was constructed using a transparent, hydrophobic photo-curable polymer with a laser-modelling techniqu...
UNLABELLED The Clinical Trials Network (CTN) of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) operates a PET/CT phantom imaging program using the CTN's oncology clinical simulator phantom, designed to validate scanners at sites that wish to participate in oncology clinical trials. Since its inception in 2008, the CTN has collected 406 well-characterized phantom datasets from 237...
The paper presents an image-guided positioning robot for a single-port brain surgery robotic manipulator. Due to its limited workspace, the robotic manipulator that performs a fine operation needs to be precisely and stably positioned near the target area. For this purpose, an accurate guidance of a positioning robot to the target position using CT images is developed. The developed brain surge...
Dose distribution was calculated and analyzed on the basis of 16-bit computed tomography (CT) images in order to investigate the effect of scanning conditions on CT for metal implants. Stainless steel and titanium rods were inserted into a phantom, and CT images were obtained by scanning the phantom under various scanning conditions: i) Fixed tube current of 230 mA and tube voltages of 100, 120...
The purpose of this study was to obtain a respiratory signal with the use of an add-on device to a specific stereotactic body frame and evaluate precision and accuracy of the method, with the use of a dynamic phantom. The authors designed and constructed a simple add-on device which, attached to a stereotactic body frame, provides information of the patient's respiratory signal in every CT axia...
introduction accurate estimation of the absorbed dose in radiosensitive organs, located away from the target volume during radiotherapy, is one of the main reasons for the development of reference phantoms. the international commission on radiological protection (icrp) reference phantoms can provide a more realistic view of the human anatomy in comparison with the previously used mathematical p...
OBJECTIVE The aim of this study was to evaluate the effect of the point spread function (PSF) and time of flight (TOF) on PET/CT images of overweight patients in relation to the iteration number and the acquisition time. METHODS This study consisted of a phantom study and a clinical study. The NEMA IEC body phantom and a 40 cm diameter large phantom (LG phantom) simulating an overweight patie...
According to published data, the absorbed dose used for a CBCT image acquisition with Varian OBI v1.3 can be as high as 100 mGy. In 2008 Varian released a new OBI version (v1.4), which promised to reduce the imaging dose. In this study, absorbed doses used for CBCT image acquisitions with the default irradiation techniques of Varian OBI v1.3 and v1.4 are measured. TLDs are used to derive dose d...
AIM To investigate the potential of reducing the radiation dose in prospectively electrocardiogram-triggered coronary computed tomography angiography (CCTA) while maintaining diagnostic image quality using an iterative reconstruction technique (IRT). METHODS AND MATERIALS Prospectively-gated CCTA were first performed on a phantom using 256-slice multi-detector CT scanner at 120 kVp, with the ...
MnPdGa, a compound crystallizing in the ${\mathrm{Ni}}_{2}\mathrm{In}$ structure, is material displaying magnetic ordering near room temperature and potential ambient-temperature magnetocaloric. Screening based on electronic structure calculations suggest that MnPdGa may exhibit high magnetocaloric figure of merit due to its strong magnetostructural coupling. Here we report preparation employ h...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید