CT artifacts: Causes and reduction techniques
... increases rapidly as the photon counts approach zero, which means that the maximum attenuation has a bigger effect on the noise than the average attenuation. In filtered backprojection, which is the standard reconstruction method on most scanners, the projection data are filtered to sharpen edges, a ...
... increases rapidly as the photon counts approach zero, which means that the maximum attenuation has a bigger effect on the noise than the average attenuation. In filtered backprojection, which is the standard reconstruction method on most scanners, the projection data are filtered to sharpen edges, a ...
Routine quality control recommendations for nuclear medicine
... nuclear medicine instrument must undergo thorough and careful acceptance testing, the aim being to verify that the instrument performs according to its specifications and its clinical purpose. Each instrument is supplied with a set of basic specifications. These have been produced by the manufacture ...
... nuclear medicine instrument must undergo thorough and careful acceptance testing, the aim being to verify that the instrument performs according to its specifications and its clinical purpose. Each instrument is supplied with a set of basic specifications. These have been produced by the manufacture ...
The Reference in Single Source CT
... You can visualize even the finest image details, for example, for the most accurate stenosis and stent analysis. It lets you see what was previously unseen. The minimized noise level of the Stellar Detector together with SAFIRE – our raw-data-based iterative reconstruction – is perfect for ultra low ...
... You can visualize even the finest image details, for example, for the most accurate stenosis and stent analysis. It lets you see what was previously unseen. The minimized noise level of the Stellar Detector together with SAFIRE – our raw-data-based iterative reconstruction – is perfect for ultra low ...
Using diagnostic radiology in human evolutionary studies
... specimen that rotates, rather than the source\detector system. Some are like medical scanners in that crosssectional images are calculated using attenuation measurements taken from a line of detectors. Others calculate a 3-D volume of CT numbers from radiographs recorded in multiple directions using ...
... specimen that rotates, rather than the source\detector system. Some are like medical scanners in that crosssectional images are calculated using attenuation measurements taken from a line of detectors. Others calculate a 3-D volume of CT numbers from radiographs recorded in multiple directions using ...
Artefacts in cone beam CT - Scientific Research Publishing
... 2.1. Noise Noise is defined as an unwanted, randomly and/or nonrandomly distributed disturbance of a signal that tends to obscure the signal’s information content from the observer. Noise affects images produced by cone beam CT units by reducing low contrast resolution, making it difficult to differ ...
... 2.1. Noise Noise is defined as an unwanted, randomly and/or nonrandomly distributed disturbance of a signal that tends to obscure the signal’s information content from the observer. Noise affects images produced by cone beam CT units by reducing low contrast resolution, making it difficult to differ ...
Initial experience with X-ray CT based attenuation correction in
... of gamma rays is complex because the energy spectrum of gamma rays is finite while X-rays are continuous. Second, our SPECT images were not scatter-corrected which would have improved image quality and the accuracy of quantification.19,20 Hendel et al.21 reported that while the specificity was signi ...
... of gamma rays is complex because the energy spectrum of gamma rays is finite while X-rays are continuous. Second, our SPECT images were not scatter-corrected which would have improved image quality and the accuracy of quantification.19,20 Hendel et al.21 reported that while the specificity was signi ...
Superior specificity in cardiac CT
... and inferior imaging techniques may further degrade its diagnostic capabilities and induce false positive findings that can cause unnecessary further testing or treatment. Siemens has taken up the challenge and has continuously introduced a powerful set of product innovations designed to reduce fals ...
... and inferior imaging techniques may further degrade its diagnostic capabilities and induce false positive findings that can cause unnecessary further testing or treatment. Siemens has taken up the challenge and has continuously introduced a powerful set of product innovations designed to reduce fals ...
el_hawary - Workspace - Imperial College London
... there is a sharp increase in signal that peaks at 55º and then rapidly reduces again. At 55º the signal intensity varies between subjects, but ranges from a 4 to 13 times ...
... there is a sharp increase in signal that peaks at 55º and then rapidly reduces again. At 55º the signal intensity varies between subjects, but ranges from a 4 to 13 times ...
Recent Advances in Brain MR Imaging
... • Laser excitation • Fluorescence depicted as color image or spectral wave form ...
... • Laser excitation • Fluorescence depicted as color image or spectral wave form ...
How does the procedure work?
... radiofrequency waves are directed at protons, the nuclei of hydrogen atoms, in a strong magnetic field. The protons are first "excited" and then "relaxed," emitting radio signals that can be computerprocessed to form an image. In the body, protons are most abundant in the hydrogen atoms of water—the ...
... radiofrequency waves are directed at protons, the nuclei of hydrogen atoms, in a strong magnetic field. The protons are first "excited" and then "relaxed," emitting radio signals that can be computerprocessed to form an image. In the body, protons are most abundant in the hydrogen atoms of water—the ...
Radiographic examination of the temporomandibular joint using
... CBCT is a new technique producing reconstructed images of high diagnostic quality using lower radiation doses than normal CT. According to the manufacturer, owing to the use of the cone-shaped X-ray beam and the “smart beam technology”, the absorbed dose from a CBCT scan is approximately equivalent ...
... CBCT is a new technique producing reconstructed images of high diagnostic quality using lower radiation doses than normal CT. According to the manufacturer, owing to the use of the cone-shaped X-ray beam and the “smart beam technology”, the absorbed dose from a CBCT scan is approximately equivalent ...
High Resolution T2-Weighted Dixon Based Whole
... Prevention or treatment of possible complications such as pain, instability, and fractures due to metastatic involvement of bones are also mandatory in evaluating cancer patients. Many nuclear medicine and radiological imaging methods have been used in detecting bone involvement of malignant disease ...
... Prevention or treatment of possible complications such as pain, instability, and fractures due to metastatic involvement of bones are also mandatory in evaluating cancer patients. Many nuclear medicine and radiological imaging methods have been used in detecting bone involvement of malignant disease ...
Here - CAI2R
... applied to suppress signal contributions from fat prior to data acquisition. However, these approaches typically fail in regions with large B0 field inhomogeneities. Chemical-shift encoding methods, also referred to as “Dixon” methods, have been shown to be more robust to B0 inhomogeneities (2). In ...
... applied to suppress signal contributions from fat prior to data acquisition. However, these approaches typically fail in regions with large B0 field inhomogeneities. Chemical-shift encoding methods, also referred to as “Dixon” methods, have been shown to be more robust to B0 inhomogeneities (2). In ...
Surface coil in the magnetic resonance imaging of the orbital
... by several methods (1). Besides standardized echography, computed tomography (CT) and magnetic resonance imaging (MRI) have become the most important tools for the evaluation of orbital anatomy and pathology (2). In most medical centers, CT is still the method of choice for orbital imaging because o ...
... by several methods (1). Besides standardized echography, computed tomography (CT) and magnetic resonance imaging (MRI) have become the most important tools for the evaluation of orbital anatomy and pathology (2). In most medical centers, CT is still the method of choice for orbital imaging because o ...
Positron Emission Tomography (PET)
... procedures will be described, as well as infection control procedures utilizing standard precautions. The role of the technologist in patient education will be identified. Pharmacology and Drug Administration Content is designed to provide basic concepts of pharmacology. The theory and practice of b ...
... procedures will be described, as well as infection control procedures utilizing standard precautions. The role of the technologist in patient education will be identified. Pharmacology and Drug Administration Content is designed to provide basic concepts of pharmacology. The theory and practice of b ...
quantitative nuclear medicine imaging: concepts
... medicine. Nevertheless, the apparent complexity and sometimes limited accuracy of these methods have prevented them from being widely used in important applications such as targeted radionuclide therapy or kinetic analysis. The intricacy of the effects degrading nuclear medicine images and the lack ...
... medicine. Nevertheless, the apparent complexity and sometimes limited accuracy of these methods have prevented them from being widely used in important applications such as targeted radionuclide therapy or kinetic analysis. The intricacy of the effects degrading nuclear medicine images and the lack ...
A New Way for Multidimensional Medical Data Management
... image databases, which enable access to a patient’s historical data, including multidimensional medical images from previous examinations and the opportunity for statistical and comparative image analyses, are key components in preventive medicine and future diagnosis [4], [5]. However, these medica ...
... image databases, which enable access to a patient’s historical data, including multidimensional medical images from previous examinations and the opportunity for statistical and comparative image analyses, are key components in preventive medicine and future diagnosis [4], [5]. However, these medica ...
a Philips Allura Xper FD20 discolorations that are very Children with vascular
... share a special interest and within a 3-dimensional volume, Children’s at Egleston, many of experience treating vascular facilitating the safe introduction these anomalies can be treated less invasively with image anomalies and are dedicated of needles and catheters guided medicine techniques, to pr ...
... share a special interest and within a 3-dimensional volume, Children’s at Egleston, many of experience treating vascular facilitating the safe introduction these anomalies can be treated less invasively with image anomalies and are dedicated of needles and catheters guided medicine techniques, to pr ...
EL CAMINO COLLEGE RADIOLOGIC TECHNOLOGY A
... o On the job training with continuing education NUCLEAR MEDICINE – uses radioactive materials called radiopharmaceuticals for diagnosis, therapy and medical research. Mina Colunga RT (N) or Mina Colunga RT (CNMT) o Post primary – an individual who has credentials in radiography, medical technology, ...
... o On the job training with continuing education NUCLEAR MEDICINE – uses radioactive materials called radiopharmaceuticals for diagnosis, therapy and medical research. Mina Colunga RT (N) or Mina Colunga RT (CNMT) o Post primary – an individual who has credentials in radiography, medical technology, ...
Investigator`s Brochure
... in cancer radiotherapy, as hypoxic cancer tissue is relatively radioresistant22. These chemical properties suggested the possibility of clinically imaging hypoxic tissue in vivo. Misonidazole, or a related compound, could be labeled with a radioisotope, and could bind to oxygen‐deprived cells co ...
... in cancer radiotherapy, as hypoxic cancer tissue is relatively radioresistant22. These chemical properties suggested the possibility of clinically imaging hypoxic tissue in vivo. Misonidazole, or a related compound, could be labeled with a radioisotope, and could bind to oxygen‐deprived cells co ...
Tissue Similarity Map of Perfusion Weighted MR Imaging in
... Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. It has been shown that cerebral perfusion in MS is reduced with the function of severity of the disease [1-3]. The purpose of this study is to use a new approach to processing PWI data that we refe ...
... Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. It has been shown that cerebral perfusion in MS is reduced with the function of severity of the disease [1-3]. The purpose of this study is to use a new approach to processing PWI data that we refe ...
Renal Cell Cancer (Staging) - Diagnostic Imaging Pathways
... 3. Dinney CPN, Lannon SG, Awad SA, et al. Analysis of imaging modalities, staging systems, and prognostic indicators for renal cell carcinoma. Urology. 1992;39(2):122-9. (Level II evidence). View the reference 4. Johnson CD, Dunnick NR, Cohan RH, et al. Renal adenocarcinoma: CT staging of 100 tumour ...
... 3. Dinney CPN, Lannon SG, Awad SA, et al. Analysis of imaging modalities, staging systems, and prognostic indicators for renal cell carcinoma. Urology. 1992;39(2):122-9. (Level II evidence). View the reference 4. Johnson CD, Dunnick NR, Cohan RH, et al. Renal adenocarcinoma: CT staging of 100 tumour ...
Perfusion-weighted magnetic resonance imaging in the evaluation
... Magnetic resonance imaging (MRI) is the gold standard method for brain assessment however the conventional MRI techniques may present limitations by only providing qualitative or anatomic parameters. Over recent decades, new complementary MRI techniques have been developed that supply quantitative p ...
... Magnetic resonance imaging (MRI) is the gold standard method for brain assessment however the conventional MRI techniques may present limitations by only providing qualitative or anatomic parameters. Over recent decades, new complementary MRI techniques have been developed that supply quantitative p ...
PowerPoint - Basics of CT
... assuming a breath-hold limit of 30 s factor 4 converts from head FOM to full body FOM assuming p = 1, otherwise Seff is increased assuming p = 1.5 since IQ is independent of pitch for MSCT ...
... assuming a breath-hold limit of 30 s factor 4 converts from head FOM to full body FOM assuming p = 1, otherwise Seff is increased assuming p = 1.5 since IQ is independent of pitch for MSCT ...
EANM procedure guideline for brain perfusion SPECT using 99mTc
... HMPAO, instability of the lipophilic form and glutathione interaction have been proposed. Differences in the retention mechanisms may account for some different behaviour of the tracers in specific disorders such as subacute stroke, where ECD distribution seems to reflect metabolic activity more clo ...
... HMPAO, instability of the lipophilic form and glutathione interaction have been proposed. Differences in the retention mechanisms may account for some different behaviour of the tracers in specific disorders such as subacute stroke, where ECD distribution seems to reflect metabolic activity more clo ...
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.