Quantifying image quality in diagnostic radiology using
... patient dose so as to maximize the ratio between the two; either to keep the information constant and minimize the dose or to increase information at constant dose. The dose to the patient undergoing an x‐ray examination has, in digital systems, a close relation to t ...
... patient dose so as to maximize the ratio between the two; either to keep the information constant and minimize the dose or to increase information at constant dose. The dose to the patient undergoing an x‐ray examination has, in digital systems, a close relation to t ...
Pseudoatrophy of the Cervical Portion of the Spinal Cord on MR
... phantom. There was an artifactual diminution of the cord diameter in the 128-step phaseencoding axis of the 128 x 256-matrix MR scan as compared with the diameter of the cord in the patients' postiohexol CT scans and in the 256 phase-encoded axis MR scan in the volunteer study. A similar discrepancy ...
... phantom. There was an artifactual diminution of the cord diameter in the 128-step phaseencoding axis of the 128 x 256-matrix MR scan as compared with the diameter of the cord in the patients' postiohexol CT scans and in the 256 phase-encoded axis MR scan in the volunteer study. A similar discrepancy ...
Contrast-Enhanced Magnetic Resonance Angiography
... contrast bolus in arteries and veins. This produces a large signal intensity difference between vessels and background tissues. The consequence of this reduction in T1, with appropriate imaging techniques, is that vessels have (transiently) very high signal intensity. Scans are acquired using rapid ...
... contrast bolus in arteries and veins. This produces a large signal intensity difference between vessels and background tissues. The consequence of this reduction in T1, with appropriate imaging techniques, is that vessels have (transiently) very high signal intensity. Scans are acquired using rapid ...
Award Winners
... MR Imaging before and after Transcatheter Embolizatión in Benign Prostatic Hyperplasia: What the Radiologist Needs to Know J. A. Ocantos, MD, Capital Federal Argentina; N. H. Kisilevzky; J. R. Coronil, MD; A. Kohan, MD; I. Ardanaz; P. ...
... MR Imaging before and after Transcatheter Embolizatión in Benign Prostatic Hyperplasia: What the Radiologist Needs to Know J. A. Ocantos, MD, Capital Federal Argentina; N. H. Kisilevzky; J. R. Coronil, MD; A. Kohan, MD; I. Ardanaz; P. ...
Recent developments in coronary computed tomography imaging
... in selected patients. Difficulties in imaging coronary arteries are mainly due to the small vessel size, the tortuous course of the coronary arteries along the heart surface and the fact that the coronary vessels are in constant motion with varying motion velocity during the cardiac cycle. The rotat ...
... in selected patients. Difficulties in imaging coronary arteries are mainly due to the small vessel size, the tortuous course of the coronary arteries along the heart surface and the fact that the coronary vessels are in constant motion with varying motion velocity during the cardiac cycle. The rotat ...
Radiology 213/3
... component. The vertical separation between each line is employed only for visualization. At a minimum, four lines are needed to completely describe any pulse sequence: one for the radio-frequency (RF) transmitter and one for each gradient (indicated as Gx, Gy, Gz, or Gsection, Gphase, Greadout). Add ...
... component. The vertical separation between each line is employed only for visualization. At a minimum, four lines are needed to completely describe any pulse sequence: one for the radio-frequency (RF) transmitter and one for each gradient (indicated as Gx, Gy, Gz, or Gsection, Gphase, Greadout). Add ...
American College of Radiology ACR Appropriateness Criteria®
... Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication ...
... Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication ...
PDF - Journal of Advanced Medical and Dental Sciences
... source and receptor rotate an arc between 180° and 360° around the patient. Signal to noise ratio (SNR) for CBCT is approximately 15 to 20%. The result is that CBCT provides excellent images of dense objects such as teeth and bone2. At first glance, this lack of soft tissue detail may seem to be a d ...
... source and receptor rotate an arc between 180° and 360° around the patient. Signal to noise ratio (SNR) for CBCT is approximately 15 to 20%. The result is that CBCT provides excellent images of dense objects such as teeth and bone2. At first glance, this lack of soft tissue detail may seem to be a d ...
Optical brain imaging in vivo: techniques and applications from
... PET is performed using contrast agents such as 2-fluoro2-deoxy-D-glucose containing radioactive isotopes of carbon, nitrogen, fluorine, or oxygen. Oxygen and glucose utilization in the brain can be imaged via the localization of these isotopes. However, resolution is typically poor, data acquisition ...
... PET is performed using contrast agents such as 2-fluoro2-deoxy-D-glucose containing radioactive isotopes of carbon, nitrogen, fluorine, or oxygen. Oxygen and glucose utilization in the brain can be imaged via the localization of these isotopes. However, resolution is typically poor, data acquisition ...
Stroke CT Angiography (CTA) - Vanderbilt University Medical Center
... Due to the narrow time window available for the initiation of thrombolytic treatment, speed is of the essence. The rationale in the workup for acute stroke is therefore to identify as quickly as possible those patients who may benefit from i.a. or i.v. thrombolysis or other available acute stroke the ...
... Due to the narrow time window available for the initiation of thrombolytic treatment, speed is of the essence. The rationale in the workup for acute stroke is therefore to identify as quickly as possible those patients who may benefit from i.a. or i.v. thrombolysis or other available acute stroke the ...
Diffusion Tensor Imaging - Psychiatry Neuroimaging Laboratory
... 1965). A basic scheme of this sequence is given in Fig. 5.2. The process starts by applying a 90° radiofrequency pulse after time (t) to shift the magnetization vector into the xy-plane. The equal precessing spins create a magnetic momentum that is rotating in the xy-plane thereby inducing a voltag ...
... 1965). A basic scheme of this sequence is given in Fig. 5.2. The process starts by applying a 90° radiofrequency pulse after time (t) to shift the magnetization vector into the xy-plane. The equal precessing spins create a magnetic momentum that is rotating in the xy-plane thereby inducing a voltag ...
Contents
... give pixel values proportional to dose, so that a portal dose image (PDI) is obtained. To calibrate the EPID for dosimetry requires that the raw pixel values are some quantitative function of the dose delivered to the EPID, ideally a linear function but that is not strictly necessary. The dosimetric ...
... give pixel values proportional to dose, so that a portal dose image (PDI) is obtained. To calibrate the EPID for dosimetry requires that the raw pixel values are some quantitative function of the dose delivered to the EPID, ideally a linear function but that is not strictly necessary. The dosimetric ...
Cone beam computed tomography: Adding three dimensions to
... of missed, undebrided canals lead to failure of endodontic treatment. Eliminating the anatomic noise and enabling to view the images in all planes make the CBCT system superior to intraoral periapical radiograph (IOPAR). Unrevealing the complex tooth morphology and internal anatomy with CBCT helps i ...
... of missed, undebrided canals lead to failure of endodontic treatment. Eliminating the anatomic noise and enabling to view the images in all planes make the CBCT system superior to intraoral periapical radiograph (IOPAR). Unrevealing the complex tooth morphology and internal anatomy with CBCT helps i ...
Modeling blurring effects due to continuous gantry rotation
... Purpose: Projections acquired with continuous gantry rotation may suffer from blurring effects, depending on the rotation speed and the exposure time of each projection. This leads to blurred reconstructions if conventional reconstruction algorithms are applied. In this paper, the authors propose a ...
... Purpose: Projections acquired with continuous gantry rotation may suffer from blurring effects, depending on the rotation speed and the exposure time of each projection. This leads to blurred reconstructions if conventional reconstruction algorithms are applied. In this paper, the authors propose a ...
Three-Dimensional Coronary Angiography
... and contrast volume, but also including reducing mistakes and errors caused by suboptimal imaging skills and technology. ■ Eugenia P. Carroll, MD, is Assistant Professor of Medicine, Division of Cardiology, University of Colorado Denver in Aurora, Colorado. She has disclosed that she holds no financ ...
... and contrast volume, but also including reducing mistakes and errors caused by suboptimal imaging skills and technology. ■ Eugenia P. Carroll, MD, is Assistant Professor of Medicine, Division of Cardiology, University of Colorado Denver in Aurora, Colorado. She has disclosed that she holds no financ ...
Slide 1
... Note: This slide has nothing to do with Spectroscopy. It is a standard imaging slide created with the 23Na nucleus and the hydrogen nucleus. It has been included to show an example of imaging done with a nuclei other than hydrogen. ...
... Note: This slide has nothing to do with Spectroscopy. It is a standard imaging slide created with the 23Na nucleus and the hydrogen nucleus. It has been included to show an example of imaging done with a nuclei other than hydrogen. ...
Direct Coronal View ofthe Shoulder with
... these two techniques for evaluation of the rotator cuff, MR imaging seems to be more effective. The accuracy ...
... these two techniques for evaluation of the rotator cuff, MR imaging seems to be more effective. The accuracy ...
AAPM Imaging Physics Curricula Subcommittee
... 2. Describe the processes by which x-ray and g-ray photons interact with individual atoms in a material and the characteristics that determine which processes are likely to occur. 3. Identify how photons and charged particles are attenuated within a material and the terms used to characterize the at ...
... 2. Describe the processes by which x-ray and g-ray photons interact with individual atoms in a material and the characteristics that determine which processes are likely to occur. 3. Identify how photons and charged particles are attenuated within a material and the terms used to characterize the at ...
Cone beam CT and conventional tomography for the detection of
... individually corrected (based on a lateral four angle “preexamination”) lateral (image plane perpendicular to the long axis of the condyle) and frontal (image plane parallel to the long axis of the condyle) tomograms in a Cranex Tome X-ray unit (Soredex, Helsinki, Finland) using photostimulable phos ...
... individually corrected (based on a lateral four angle “preexamination”) lateral (image plane perpendicular to the long axis of the condyle) and frontal (image plane parallel to the long axis of the condyle) tomograms in a Cranex Tome X-ray unit (Soredex, Helsinki, Finland) using photostimulable phos ...
Sir Godfrey Newbold Hounsfield KT CBE. 28 August 1919
... By the early 1970s, X-radiography had become mature and clinically indispensable; however, recent progress had been driven primarily by the evolution of clinical and radiographic techniques rather than by innovations in instrumentation. Moreover, X-radiography was not the only method of imaging. Rad ...
... By the early 1970s, X-radiography had become mature and clinically indispensable; however, recent progress had been driven primarily by the evolution of clinical and radiographic techniques rather than by innovations in instrumentation. Moreover, X-radiography was not the only method of imaging. Rad ...
Three-dimensional ultrasound imaging
... conventional transducer about an axis parallel to the transducer face while the 2D images are acquired at regular angular intervals, so that they form a fan of images radial to the axis as shown in figure 1(b). This type of motion is possible with an integrated 3D probe as well as with an external f ...
... conventional transducer about an axis parallel to the transducer face while the 2D images are acquired at regular angular intervals, so that they form a fan of images radial to the axis as shown in figure 1(b). This type of motion is possible with an integrated 3D probe as well as with an external f ...
Making the difference with Philips Live Image
... Xper Modules that have the same functionality as the Xper Module in the examination room. Adding a second Imaging or Geometry Module in the control room works in a master-slave configuration. ...
... Xper Modules that have the same functionality as the Xper Module in the examination room. Adding a second Imaging or Geometry Module in the control room works in a master-slave configuration. ...
The Synthesis and Evaluation of Peptide
... Figure 1.2 Components of a molecular imaging probe containing the targeting entity, the linker and a label .................................................................................................................. 2 Figure 1.3 [18F]Galacto-RGD, a PET imaging agent for oncologic applications ...
... Figure 1.2 Components of a molecular imaging probe containing the targeting entity, the linker and a label .................................................................................................................. 2 Figure 1.3 [18F]Galacto-RGD, a PET imaging agent for oncologic applications ...
The Role of Dynamic Contrast Enhanced Magnetic
... Objective: To show the magnetic resonance imaging characteristics of soft tissue masses, and to evaluate the aid of contrast-enhanced static and dynamic magnetic resonance imaging for the differentiation of benign and malignant lesions. Methods: A total of 35 soft tissue masses (16 benign and 19 mal ...
... Objective: To show the magnetic resonance imaging characteristics of soft tissue masses, and to evaluate the aid of contrast-enhanced static and dynamic magnetic resonance imaging for the differentiation of benign and malignant lesions. Methods: A total of 35 soft tissue masses (16 benign and 19 mal ...
Isotropic diffusion weighting in radial fast spin
... averaged to yield a “trace” image with average diffusion weighting (2). Because the trace of the diffusion tensor is invariant to rotation, the intensity in the resulting trace image is invariant to tissue orientation (7). A number of schemes for imparting isotropic diffusion weighting in individual ...
... averaged to yield a “trace” image with average diffusion weighting (2). Because the trace of the diffusion tensor is invariant to rotation, the intensity in the resulting trace image is invariant to tissue orientation (7). A number of schemes for imparting isotropic diffusion weighting in individual ...
Positron emission tomography
Positron emission tomography (PET) is a nuclear medicine, functional imaging technique that produces a three-dimensional image of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Three-dimensional images of tracer concentration within the body are then constructed by computer analysis. In modern PET-CT scanners, three dimensional imaging is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session, in the same machine.If the biologically active molecule chosen for PET is fluorodeoxyglucose (FDG), an analogue of glucose, the concentrations of tracer imaged will indicate tissue metabolic activity as it corresponds to the regional glucose uptake. Use of this tracer to explore the possibility of cancer metastasis (i.e., spreading to other sites) is the most common type of PET scan in standard medical care (90% of current scans). However, on a minority basis, many other radioactive tracers are used in PET to image the tissue concentration of other types of molecules of interest. One of the disadvantages of PET scanners is their operating cost.