INFORMATICS (2)
問題一覧
1
INTERACTION OF A PHOTON WITH A LOW-ENERGY ELECTRON. IF THE PHOTON HAS A SUFFICIENTENERGY, THEN THE ELECTRON IS SEPARATED FROM THE ATOM, WITH ANY EXCESS ENERGY, FROM THE PHOTON BEING TRANSFORMED INTO THE ELECTRON’S KINETIC ENERGY.
PHOTOELECTRIC EFFECT
2
Rather than being absorbed, when a high-energy photon collides with an electron, both particles may instead be deflected.
COMPTON EFFECT
3
X-ray can undergo a change in direction but no change in wavelength (energy)
-Thomson and Rayleigh scatter are examples of this occurrence.
-Usually less than 5% of the radiation undergoes this effect.
COHERENT SCATTERING
4
A fourth type of interaction is possible, known as
PAIR PRODUCTION
5
The degree to which a given substance allows an x-ray to pass through is referred to as
ATTENUATION
6
Controlled and focused source of x-rays is allowed to pass through the anatomy of interest; a detector is then responsible for quantifying the amount and pattern of x-ray photons, converting the information into a visual image
IMAGING
7
X-ray machine provide a static image on radiograph.
-X-rays are the oldest and most frequently used form of medical imaging.
-They are often used to help diagnosed fractured bones, look for injury and to locate foreign objects in soft tissue.
RADIOGRAPHY (X-RAY)
8
fluoroscopy is based on x-rays.
-X-ray tube is installed.
-the radiation dose is higher than radiography(x-ray)
Provide both static and dynamic image.
FLOUROSCOPY
9
Mid-20th century in x-ray reconstruction and the theory behind Axial tomography led to the development of the first commercial computed tomography (CT) scanner in 1971 for clinical purposes.
-CT provides much improved subject contrast with discrimination less than1% and the current generation of multi-slice CT scanners provide sub-millimeter resolution.
COMPUTED TOMOGRAPHY
10
Central to CT imaging is a means to efficiently perform the inverse Radon transform.
RECONSTRUCTION ALGORITHMS
11
The most straightforward method to reconstruct a 2D
image starts by assuming an empty, equally-spaced image matrix.
The back-projection is created by “smearing” a ray back through the image in the
direction it was originally acquired.
SIMPLE BACK PROJECTION
12
To overcome the blurring in simple back-projection,each ray can be filtered or convolved with a kernel prior to the back-projection. In filtered back-projection, the filter has the effect of weighting the center of a ray while underweighting the periphery, thus counteracting the blur.
FILTERED BACK-PROJECTION
13
Both simple and filtered back-projection algorithms can be run while raw image data is acquired, allowing for more immediate reconstruction. In comparison, series expansion techniques (also known as iterative techniques and algebraic reconstruction) require that all x-ray attenuation data be available before reconstruction commences.
SERIES EXPANSION
14
he results of a reconstruction algorithm are a measure of the attenuation for a given pixel location (x,y). These values are normalized to Hounsfield units (HU) prior to generation as final image.
HOUNSFIELD UNITS
15
Based on Hounsfield units, anatomical CT images
have a typical grayscale value range of 212 bits (4,096 values)
DISPLAY: WINDOWING AND LEVELLING
16
well-known nuclear medicine imaging
technique is PET, which looks to detect gamma rays emitted by an injected short-life radioactive compound. This compound, called a radiopharmaceutical, radiotracer, or radionuclide, is given intravenously and dependent on what type of isotope is injected, emissions occur either as a single photon, which forms the basis for single photon emission tomography (SPECT); or with a higher energy level, positrons, which form the basis for positron emission tomography.
POSITRON EMISSION TOMOGRAPHY (PET/CT)
17
Developed for clinical purposes in the 1970s, magnetic resonance (MR) imaging is based on the use of a strong magnetic field to align the nuclear magnetization of hydrogen atoms in water molecules.
MAGNETIC RESONANCE IMAGING (MRI)
18
principles of sonar (sound navigation and ranging) began to appear shortly after the end of World War II. Donald et al. developed the first prototype ultrasound scanner and reported its diagnostic utility in identifying normal abdominal organs and several common pathological processes.
ULTRA SOUND IMAGING
19
The introduction of the American College of Radiology (ACR) Mammography Accreditation Program in 1987 and the Mammography Quality
Standards Act in 1994 are among the most significant of these efforts [58]. Standardized
documentation of mammographic findings via the ACR Breast Imaging Reporting
and Data System (BI-RADS)
-Specific to woman’s or man’s breast
-Lower dose
-Used as cancer screening
MAMMOGRAPHY
RAD PATHOLOGY
RAD PATHOLOGY
ユーザ名非公開 · 35問 · 1年前RAD PATHOLOGY
RAD PATHOLOGY
35問 • 1年前ユーザ名非公開
ULTRASOUND
ULTRASOUND
ユーザ名非公開 · 34問 · 1年前ULTRASOUND
ULTRASOUND
34問 • 1年前ユーザ名非公開
ETHICS
ETHICS
ユーザ名非公開 · 61問 · 1年前ETHICS
ETHICS
61問 • 1年前ユーザ名非公開
RPC
RPC
ユーザ名非公開 · 76問 · 1年前RPC
RPC
76問 • 1年前ユーザ名非公開
RPC DISCOVERY OF X-RAY
RPC DISCOVERY OF X-RAY
ユーザ名非公開 · 10問 · 1年前RPC DISCOVERY OF X-RAY
RPC DISCOVERY OF X-RAY
10問 • 1年前ユーザ名非公開
RPC ESSENTIAL CONCEPTS OF RADIOLOGIC SCIENCES
RPC ESSENTIAL CONCEPTS OF RADIOLOGIC SCIENCES
ユーザ名非公開 · 33問 · 1年前RPC ESSENTIAL CONCEPTS OF RADIOLOGIC SCIENCES
RPC ESSENTIAL CONCEPTS OF RADIOLOGIC SCIENCES
33問 • 1年前ユーザ名非公開
RPC 3
RPC 3
ユーザ名非公開 · 35問 · 1年前RPC 3
RPC 3
35問 • 1年前ユーザ名非公開
RPC 3
RPC 3
ユーザ名非公開 · 35問 · 1年前RPC 3
RPC 3
35問 • 1年前ユーザ名非公開
問題一覧
1
INTERACTION OF A PHOTON WITH A LOW-ENERGY ELECTRON. IF THE PHOTON HAS A SUFFICIENTENERGY, THEN THE ELECTRON IS SEPARATED FROM THE ATOM, WITH ANY EXCESS ENERGY, FROM THE PHOTON BEING TRANSFORMED INTO THE ELECTRON’S KINETIC ENERGY.
PHOTOELECTRIC EFFECT
2
Rather than being absorbed, when a high-energy photon collides with an electron, both particles may instead be deflected.
COMPTON EFFECT
3
X-ray can undergo a change in direction but no change in wavelength (energy)
-Thomson and Rayleigh scatter are examples of this occurrence.
-Usually less than 5% of the radiation undergoes this effect.
COHERENT SCATTERING
4
A fourth type of interaction is possible, known as
PAIR PRODUCTION
5
The degree to which a given substance allows an x-ray to pass through is referred to as
ATTENUATION
6
Controlled and focused source of x-rays is allowed to pass through the anatomy of interest; a detector is then responsible for quantifying the amount and pattern of x-ray photons, converting the information into a visual image
IMAGING
7
X-ray machine provide a static image on radiograph.
-X-rays are the oldest and most frequently used form of medical imaging.
-They are often used to help diagnosed fractured bones, look for injury and to locate foreign objects in soft tissue.
RADIOGRAPHY (X-RAY)
8
fluoroscopy is based on x-rays.
-X-ray tube is installed.
-the radiation dose is higher than radiography(x-ray)
Provide both static and dynamic image.
FLOUROSCOPY
9
Mid-20th century in x-ray reconstruction and the theory behind Axial tomography led to the development of the first commercial computed tomography (CT) scanner in 1971 for clinical purposes.
-CT provides much improved subject contrast with discrimination less than1% and the current generation of multi-slice CT scanners provide sub-millimeter resolution.
COMPUTED TOMOGRAPHY
10
Central to CT imaging is a means to efficiently perform the inverse Radon transform.
RECONSTRUCTION ALGORITHMS
11
The most straightforward method to reconstruct a 2D
image starts by assuming an empty, equally-spaced image matrix.
The back-projection is created by “smearing” a ray back through the image in the
direction it was originally acquired.
SIMPLE BACK PROJECTION
12
To overcome the blurring in simple back-projection,each ray can be filtered or convolved with a kernel prior to the back-projection. In filtered back-projection, the filter has the effect of weighting the center of a ray while underweighting the periphery, thus counteracting the blur.
FILTERED BACK-PROJECTION
13
Both simple and filtered back-projection algorithms can be run while raw image data is acquired, allowing for more immediate reconstruction. In comparison, series expansion techniques (also known as iterative techniques and algebraic reconstruction) require that all x-ray attenuation data be available before reconstruction commences.
SERIES EXPANSION
14
he results of a reconstruction algorithm are a measure of the attenuation for a given pixel location (x,y). These values are normalized to Hounsfield units (HU) prior to generation as final image.
HOUNSFIELD UNITS
15
Based on Hounsfield units, anatomical CT images
have a typical grayscale value range of 212 bits (4,096 values)
DISPLAY: WINDOWING AND LEVELLING
16
well-known nuclear medicine imaging
technique is PET, which looks to detect gamma rays emitted by an injected short-life radioactive compound. This compound, called a radiopharmaceutical, radiotracer, or radionuclide, is given intravenously and dependent on what type of isotope is injected, emissions occur either as a single photon, which forms the basis for single photon emission tomography (SPECT); or with a higher energy level, positrons, which form the basis for positron emission tomography.
POSITRON EMISSION TOMOGRAPHY (PET/CT)
17
Developed for clinical purposes in the 1970s, magnetic resonance (MR) imaging is based on the use of a strong magnetic field to align the nuclear magnetization of hydrogen atoms in water molecules.
MAGNETIC RESONANCE IMAGING (MRI)
18
principles of sonar (sound navigation and ranging) began to appear shortly after the end of World War II. Donald et al. developed the first prototype ultrasound scanner and reported its diagnostic utility in identifying normal abdominal organs and several common pathological processes.
ULTRA SOUND IMAGING
19
The introduction of the American College of Radiology (ACR) Mammography Accreditation Program in 1987 and the Mammography Quality
Standards Act in 1994 are among the most significant of these efforts [58]. Standardized
documentation of mammographic findings via the ACR Breast Imaging Reporting
and Data System (BI-RADS)
-Specific to woman’s or man’s breast
-Lower dose
-Used as cancer screening
MAMMOGRAPHY