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Dentomaxillofacial Radiology
Dentomaxillofacial Radiology

... ranging from 0.03 mm to 0.52 mm (maximum overestimation 0.03 mm, maximum underestimation 0.52 mm), resulting in a distortion ratio ranging from 0% to 6% when expressed in percentages. Discussion Welander et al5 described how advanced panoramic machines that combine a translational movement with a pe ...
Radioactivity & Medicine I
Radioactivity & Medicine I

... oxygen or glucose (sugar) which have been labeled with radionuclides such as 11C, 13N, 15O and 18F (18F being the most common). •  18F is very useful because of its long half-life (109 min), and because it decays be emitting positrons having the lowest positron energy, which generally allows for the ...
(mIBG) Scintigraphy - Society of Nuclear Medicine
(mIBG) Scintigraphy - Society of Nuclear Medicine

... chamber. ...
Volumetric Perfusion CT Using Prototype 256
Volumetric Perfusion CT Using Prototype 256

... Prototype 256 –Detector Row CT The prototype 256 – detector row CT (2, 4) uses a wide-area cylindrical 2D detector designed on the basis of present CT technology and mounted on the gantry frame of a 16 – detector row CT (5; Aquilion, Toshiba Medical Systems, Otawara, Japan). It has 912 (transverse) ...
WP DIGITAL MAMMO rev3
WP DIGITAL MAMMO rev3

... of 250 microns is adequate to stop more than 95 percent of the X-rays in the mammographic energy range. This is seen in Figure 7. Standard screens for use in film mammography only have about 50 to 70 percent quantum efficiency, and the scintillator CsI(Tl) used in indirect-conversion digital detecto ...
WP DIGITAL MAMMO rev3 (5)
WP DIGITAL MAMMO rev3 (5)

... of 250 microns is adequate to stop more than 95 percent of the X-rays in the mammographic energy range. This is seen in Figure 7. Standard screens for use in film mammography only have about 50 to 70 percent quantum efficiency, and the scintillator CsI(Tl) used in indirect-conversion digital detecto ...
Multiply Your Potential
Multiply Your Potential

... of excited Flash users is continuously growing – not least because current Flash users are already purchasing their second, third, fourth, and even up to tenth system. The latest Dual Source Dual Energy CT scanner has the fastest volume acquisition speed and highest heart rate-independent temporal r ...
the place of clinical radiology and imaging in medical education
the place of clinical radiology and imaging in medical education

... Clinical radiology is now integral to clinical management and understanding of imaging is fundamental to ensuring appropriate clinical practice. New legislation places legal responsibility on clinical staff who refer patients for investigations involving radiation exposure. Legal requirements relati ...
Cirsoid aneurysm of scalp
Cirsoid aneurysm of scalp

... the superficial temporal arteries. ▸ A CT angiography can play a pivotal role in planning the treatment by tracing the feeder vessels and giving the relation of lesion with adjacent structures. ▸ Catheter angiography is still a gold standard technique with therapeutic benefits. ...
Clinical applications of basic x
Clinical applications of basic x

... used, and motion) affect radiographic image quality. An understanding of how x rays are produced and interact in tissue is essential to determine the appropriate selection of technique factors and equipment design for a particular clinical examination. The appearance of a radiograph is described by ...
Comparison of clinical and physical measures of image quality in
Comparison of clinical and physical measures of image quality in

... Image quality in digital chest PA and pelvis AP was assessed using two different methods; one based on observations of images of an anthropomorphic phantom, one based on computer modelling using an anthropomorphic voxel phantom. The tube voltage was varied within a broad range (50-150 kV), including ...
Thomas R. Nelson, Ph.D. Professor of Radiology UC San Diego
Thomas R. Nelson, Ph.D. Professor of Radiology UC San Diego

... • Mutual information is the amount that the uncertainty in B (or A) is reduced when A (or B) is known. • 2) I(A,B) = H(A) + H(B) - H(A,B) • Maximizing the mutual info is equivalent to minimizing the joint entropy (last term) • Advantage in using mutual info over joint entropy is it includes the indi ...
Venous malformations
Venous malformations

... + Surgery Debulking For large, infiltrating malformations that are difficult to delineate, combined sclerotherapy with ablative and reconstructive surgery is indicated ...
From MI Gateway - Society of Nuclear Medicine
From MI Gateway - Society of Nuclear Medicine

... MR will be exceptional for applications in which PET/CT use is limited due to reduced CT soft-tissue contrast. For example, the superior MR soft tissue contrast will be beneficial for head and neck cancer, thyroid cancer, lung cancer with suspicion of chest wall invasion, gynecological malignancies, ...
Code of Practice for Diagnostic and Interventional Radiology: Draft
Code of Practice for Diagnostic and Interventional Radiology: Draft

... Secondary shielding – 1.5 mm lead equivalence in X-ray rooms where computed tomography equipment is performed, 18 mm gypsum plasterboard equivalence in all X-ray rooms where mammography or dual energy X-ray absorptiometry is performed and 1.0 mm lead equivalence for all other X-ray rooms. Supervised ...
Code of Practice for Diagnostic and Interventional Radiology: Draft
Code of Practice for Diagnostic and Interventional Radiology: Draft

... Secondary shielding – 1.5 mm lead equivalence in X-ray rooms where computed tomography equipment is performed, 18 mm gypsum plasterboard equivalence in all X-ray rooms where mammography or dual energy X-ray absorptiometry is performed and 1.0 mm lead equivalence for all other X-ray rooms. Supervised ...
Imaging - Touch Neurology
Imaging - Touch Neurology

... Neuroimaging is a critical component of patient care in multiple stages of cerebrovascular disease. Most imaging focuses on measurements of tissue or vascular structure, with comparatively less emphasis on function. Furthermore, imaging approaches that rely on exogenous contrast agents or ionising r ...
How to Obtain Digital Radiographs of the Thoracolumbar Spine in
How to Obtain Digital Radiographs of the Thoracolumbar Spine in

... from performing comprehensive radiographic examinations of the back, because their size and thickness restricted the quality of the image. DR systems have facilitated detection of lesions in the thoracolumbar spine in horses with clinical manifestations of back pain by enhancing specific viewing area ...
IMRT verification by three-dimensional dose reconstruction
IMRT verification by three-dimensional dose reconstruction

... camera-based,7,8 liquid ionization chamber-based9–12 and amorphous silicon flat-panel13,14 systems. Pretreatment verification of 2-D intensity-modulated beam portals has also been demonstrated for both camera-based15,16 and liquid ionization chamber-based systems.17,18 In vivo dosimetric measurement ...
Table of Contents
Table of Contents

... material’s attenuation coefficient increases, the amount of energy that can pass through the material decreases. Bones have a much higher coefficient of attenuation than soft tissues, creating contrast between bone and soft tissue in X-ray images. The CT scanner takes projections from many angles a ...
technique - Montgomery College
technique - Montgomery College

... • Variable kVp, Fixed mAs– short contrast/more pt exposure • Fixed kVp, Variable mAs – Prefered, longer contrast less patient exposure • High kVp chart – For exams using 100 kVp or higher • Automatic exposure-PATIENT POSITIONING --VERY IMPORTANT ...
(MRI) of the Soft - American College of Radiology
(MRI) of the Soft - American College of Radiology

... patients. Practice Parameters and Technical Standards are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care1. For these reasons and those set forth below, the American College of Radiology and our collaborating medic ...
Understanding Radiation Units - Radiation Protection of Patients
Understanding Radiation Units - Radiation Protection of Patients

... L02. Understanding radiation units ...
A Compton scattering image reconstruction algorithm based on total
A Compton scattering image reconstruction algorithm based on total

... is proposed. The reconstruction problem is described as an optimization problem with nonlinear data-consistency constraint. The simulated results show that the proposed algorithm could reduce reconstruction error and improve image quality, especially when there are not enough measurements. ...
Study on the Computed Tomography Dose Index volume
Study on the Computed Tomography Dose Index volume

... Majority examinations of multi slice CT scan are performed in helical mode and issues regarding dose still an area of some debate on these system especially for those who had repeated CT examinations since the effective dose from CT scan on average is ~10 mSv [1]. Therefore, once a CT examination is ...
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Image-guided radiation therapy

Image-guided radiation therapy (IGRT) is the process of frequent two and three-dimensional imaging, during a course of radiation treatment, used to direct radiation therapy utilizing the imaging coordinates of the actual radiation treatment plan. The patient is localized in the treatment room in the same position as planned from the reference imaging dataset. An example of IGRT would include localization of a cone beam computed tomography (CBCT) dataset with the planning computed tomography (CT) dataset from planning. IGRT would also include matching planar kilovoltage (kV) radiographs or megavoltage (MV) images with digital reconstructed radiographs (DRRs) from the planning CT. These two methods comprise the bulk of IGRT strategies currently employed circa 2013.This process is distinct from the use of imaging to delineate targets and organs in the planning process of radiation therapy. However, there is clearly a connection between the imaging processes as IGRT relies directly on the imaging modalities from planning as the reference coordinates for localizing the patient. The variety of medical imaging technologies used in planning includes x-ray computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) among others. The precision of IGRT is significantly improved when N-localizer technology is used in conjunction with these medical imaging technologies. Through advancements in imaging technology, combined with a further understanding of human biology at the molecular level, the impact of IGRT on radiotherapy treatment continues to evolve.
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