The document discusses the technical aspects of how CT scans produce images. It explains that shades of gray in CT images represent varying degrees of x-ray attenuation as beams pass through structures of different densities. Photons may be absorbed or scattered depending on the object's thickness, density, and atomic number. The linear attenuation coefficient quantifies the absorption and scattering of photons per unit thickness. Differences in this coefficient among tissues produce image contrast in CT scans. Hounsfield units are used to measure attenuation and assign values to tissues and objects visible in CT images. Technical components like the x-ray tube, filters, and slip rings that allow continuous rotation are described.
CT scan and MRI are the techniques for body imaging. Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage.
Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage. Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage. MRI stands for Magentic Resonance Imaging which is a non-invasive medical imaging test that produces detailed images of almost every internal structure in the human body, including the organs, bones, muscles and blood vessels.
MRI scanners create images of the body using a large magnet and radio waves.
No ionizing radiation is produced during an MRI exam, unlike X-rays. These images give your physician important information in diagnosing your medical condition and planning a course of treatment.
Raymond Damadian, the inventor of the first magnetic resonance scanning machine performed the first full-body scan of a human being in 1977.
The Nobel Prize was awarded to the American chemist, Paul Lauterbur, and the British physicist, Peter Mansfield, for developing a method to represent the information gathered by a scanner as an image. This is fundamental for the way the technology is used today.
The document summarizes the history and technology of computed tomography (CT) scanners. It describes how CT was developed in the 1970s by Godfrey Hounsfield and Alan Cormack, who were later awarded the Nobel Prize. It outlines the key innovations in each generation of CT scanners, from the first generation's pencil beam geometry to later generations' use of detector arrays and helical scanning, which reduced scan times. The document also discusses the components of a CT scanner, including the x-ray tube, detectors, and techniques for image reconstruction and calibration.
Computerized tomography (CT) was pioneered by Godfrey Hounsfield and Allan Cormack in the 1970s. CT uses X-rays and computer processing to create cross-sectional images of the body. The first CT scanners used a translate-rotate design, while later generations used multiple detectors and spiral scanning for faster, more detailed imaging. Image reconstruction uses back projection to convert attenuation measurements into pixel values and display slices. CT provides excellent anatomical detail and is widely used for diagnosing conditions of the brain, blood vessels, lungs and other organs.
LCU RDG 402 PRINCIPLES OF COMPUTED TOMOGRAPHY.pptxEmmanuelOluseyi1
This document provides an outline for a course on principles of computed tomography. It discusses key topics that will be covered, including image digitization, computed radiography, basic CT principles, and care of radiographic equipment. The objectives are for students to understand the principles of image digitization, computed radiography, CT scanning, and components of CT machines. It also explains some of the technical aspects of digital imaging, spatial resolution, CT scanning principles, CT equipment components like the gantry and x-ray tube, and characteristics of ideal x-ray detectors.
CT scanning provides cross-sectional images of the body which can be manipulated and reformatted in various planes. It uses X-rays combined with computer processing to generate 3D images of tissues and organs. CT scanning is more detailed than standard X-rays and can detect abnormalities such as tumors, bleeding, fractures and blockages. It has various medical applications for imaging organs like the brain, lungs, kidneys and blood vessels. While it provides advantages over other imaging methods, it also involves exposure to ionizing radiation.
The document discusses computed tomography (CT) scanning. It begins by introducing CT and comparing it to conventional radiography. CT provides more accurate diagnostic information by reconstructing 3D structures from multiple 2D projections, unlike conventional radiography which produces 2D shadow images. The document then covers key aspects of CT scanning including the components involved in data acquisition, the reconstruction process, and parameters such as slice thickness and radiation dose. It also describes advances in CT technology over generations from narrow single detector scans to modern multi-detector scanners.
The document discusses computed tomography (CT) scanning. It begins by introducing CT and comparing it to conventional radiography. CT provides more accurate diagnostic information by reconstructing 3D structures from multiple 2D projections, unlike conventional radiography which produces 2D shadow images. The document then covers key aspects of CT scanning including the components involved in data acquisition, the reconstruction process, and parameters such as slice thickness and radiation dose. It also describes advances in CT technology over generations from narrow single detector scans to current multi-detector scanners.
CT scan and MRI are the techniques for body imaging. Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage.
Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage. Computed Tomography or Computerized Axial Tomography is commonly referred to as a CT scan.
C- computed (Use of computer) and T- tomography (Greek word “Tomos” means “slice” and “Grapho” means “ To write”
The first commercial CT scanner was invented by Sir Godfrey Hounsfield in United Kingdom.
It is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce images of the inside of the body. It shows detailed images of any part of the body including the bones, muscles, fat, organs and blood vessels.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage. MRI stands for Magentic Resonance Imaging which is a non-invasive medical imaging test that produces detailed images of almost every internal structure in the human body, including the organs, bones, muscles and blood vessels.
MRI scanners create images of the body using a large magnet and radio waves.
No ionizing radiation is produced during an MRI exam, unlike X-rays. These images give your physician important information in diagnosing your medical condition and planning a course of treatment.
Raymond Damadian, the inventor of the first magnetic resonance scanning machine performed the first full-body scan of a human being in 1977.
The Nobel Prize was awarded to the American chemist, Paul Lauterbur, and the British physicist, Peter Mansfield, for developing a method to represent the information gathered by a scanner as an image. This is fundamental for the way the technology is used today.
The document summarizes the history and technology of computed tomography (CT) scanners. It describes how CT was developed in the 1970s by Godfrey Hounsfield and Alan Cormack, who were later awarded the Nobel Prize. It outlines the key innovations in each generation of CT scanners, from the first generation's pencil beam geometry to later generations' use of detector arrays and helical scanning, which reduced scan times. The document also discusses the components of a CT scanner, including the x-ray tube, detectors, and techniques for image reconstruction and calibration.
Computerized tomography (CT) was pioneered by Godfrey Hounsfield and Allan Cormack in the 1970s. CT uses X-rays and computer processing to create cross-sectional images of the body. The first CT scanners used a translate-rotate design, while later generations used multiple detectors and spiral scanning for faster, more detailed imaging. Image reconstruction uses back projection to convert attenuation measurements into pixel values and display slices. CT provides excellent anatomical detail and is widely used for diagnosing conditions of the brain, blood vessels, lungs and other organs.
LCU RDG 402 PRINCIPLES OF COMPUTED TOMOGRAPHY.pptxEmmanuelOluseyi1
This document provides an outline for a course on principles of computed tomography. It discusses key topics that will be covered, including image digitization, computed radiography, basic CT principles, and care of radiographic equipment. The objectives are for students to understand the principles of image digitization, computed radiography, CT scanning, and components of CT machines. It also explains some of the technical aspects of digital imaging, spatial resolution, CT scanning principles, CT equipment components like the gantry and x-ray tube, and characteristics of ideal x-ray detectors.
CT scanning provides cross-sectional images of the body which can be manipulated and reformatted in various planes. It uses X-rays combined with computer processing to generate 3D images of tissues and organs. CT scanning is more detailed than standard X-rays and can detect abnormalities such as tumors, bleeding, fractures and blockages. It has various medical applications for imaging organs like the brain, lungs, kidneys and blood vessels. While it provides advantages over other imaging methods, it also involves exposure to ionizing radiation.
The document discusses computed tomography (CT) scanning. It begins by introducing CT and comparing it to conventional radiography. CT provides more accurate diagnostic information by reconstructing 3D structures from multiple 2D projections, unlike conventional radiography which produces 2D shadow images. The document then covers key aspects of CT scanning including the components involved in data acquisition, the reconstruction process, and parameters such as slice thickness and radiation dose. It also describes advances in CT technology over generations from narrow single detector scans to modern multi-detector scanners.
The document discusses computed tomography (CT) scanning. It begins by introducing CT and comparing it to conventional radiography. CT provides more accurate diagnostic information by reconstructing 3D structures from multiple 2D projections, unlike conventional radiography which produces 2D shadow images. The document then covers key aspects of CT scanning including the components involved in data acquisition, the reconstruction process, and parameters such as slice thickness and radiation dose. It also describes advances in CT technology over generations from narrow single detector scans to current multi-detector scanners.
Basic physics of multidetector computed tomography ( CT Scan) - how ct scan works, different generations of ct, how image is generated and displayed and image artifacts related to CT Scan.
This document provides an overview of computed tomography (CT) and magnetic resonance imaging (MRI). It discusses the history and development of CT from the early 1970s to present day, including the evolution from first to fifth generation CT scanners. Key aspects of CT technology covered include the basic principles, components like the x-ray tube and detectors, and types of scans like conventional tomography and cone beam CT. The document also briefly introduces magnetic resonance imaging.
The document provides an overview of the basic principles of CT scanning. It discusses key differences between radiography and CT imaging, including that CT produces cross-sectional images without overlaying structures. It describes the CT scanning process where an X-ray beam passes through the patient and is measured to construct voxel values and pixels. CT numbers represent attenuation coefficients measured in Hounsfield units. The document also covers topics like polychromatic beams, volume averaging effects, raw vs image data, and different scan modes like step-and-shoot and helical scanning.
Computed Tomography and Spiral Computed Tomography JAMES JACKY
1. Computed Tomography / Spiral Computed Tomography
2. Clinical and Principle Operation of Computed Tomography
3. Law and Regulation in Malaysia
4. Radiation Dose
Lecture 3 & 4 anam sanam chick ldkfdlsfldfjdlsjfdlks .pptxfaiz3334
Computed tomography (CT) scans create cross-sectional images of the body by using X-rays and computer processing. An X-ray tube rotates around the body and produces multiple images from different angles, which are used to reconstruct cross-sectional slices using back projection. These slices can be combined to create 3D images. CT scans provide more detailed images than basic X-rays due to their ability to distinguish between different tissue densities and visualize structures throughout the body.
Computed tomography (CT) provides cross-sectional images of the body using X-rays. CT has evolved through several generations with advances in technology. Modern multi-detector CT allows acquisition of multiple slices simultaneously, reducing scan time. Helical or spiral CT involves continuous table movement and X-ray rotation, allowing whole organ or body coverage with minimal artifacts. Pitch relates the table speed to beam width and affects radiation dose and anatomic coverage. CT has advantages over conventional radiography including better contrast resolution and ability to distinguish between tissues.
Computed tomography (CT) uses rotating X-rays and computer processing to create cross-sectional images of the body. CT provides advantages over conventional radiography like distinguishing between tissues with similar densities and detecting differences as small as 0.5% contrast. Modern CT systems use multiple detector rows to acquire multiple slices simultaneously during each rotation, improving coverage and reducing scan time. Advanced techniques like multiplanar reformation and 3D rendering provide additional diagnostic information from CT images. Artifacts can arise from factors like the helical acquisition and differences between detector rows.
Computed tomography (CT) uses computer-processed X-rays to create cross-sectional images of the body. CT works by rotating an X-ray tube and detectors around the patient, acquiring multiple transmission measurements at different angles to reconstruct a 3D image. Image reconstruction involves algorithms like back projection and filtered back projection that use the transmission data to calculate the attenuation coefficients of different tissues and generate tomographic images representing slices of the body. CT numbers, measured in Hounsfield units, provide standardized values related to tissue density and visibility.
its about the CT scan and generations in the form of PPT explaining each of first generation , second generation, third generation, fourth generation, fith generation and sith generation
This document discusses various types of artifacts that are commonly encountered in clinical CT imaging. It describes ring artifacts, noise, beam hardening, scatter, motion artifacts, cone-beam artifacts, and metal artifacts. For each type of artifact, it explains the potential causes, appearance, and techniques for reducing the artifacts, such as increasing mAs, iterative reconstruction methods, and dual energy CT. Modern scanners have implemented various corrections but artifacts still occur and understanding their causes is important for accurate image interpretation.
This document provides information about computerized tomography (CT) scans. It defines CT scanning as a medical imaging method that generates 3D images of internal organs from a series of 2D X-ray images taken around a single axis of rotation. The history section describes how the first commercially viable CT scanner was invented in the 1970s in the UK and how subsequent innovations improved scanning speed and image quality. The document also summarizes different generations of CT scanners and their technical specifications.
Computed tomography (CT scan) is a medical imaging procedure that uses computer-processed X-rays to produce tomographic images or 'slices' of specific areas of the body. These cross-sectional images are used for diagnostic and therapeutic purposes in various medical disciplines.
Physical principle of Computed Tomography (Scanning principle & Data acquisit...ThejaTej6
Computed tomography (CT) uses x-rays and computer processing to produce cross-sectional images of the body. CT scanners are composed of an x-ray tube, detectors, and a rotating gantry. During a scan, the gantry rotates around the patient as they pass through, emitting a narrow x-ray beam and detecting the transmitted x-rays. The detected data is used to construct tomographic images, or slices, of the body. CT images provide more detailed information than conventional x-rays by measuring the attenuation of x-rays through tissues.
CT scanners produce cross-sectional images of the body by using X-rays from different angles to reconstruct tomographic slices. CT scanners rotate an X-ray tube and detector array around the patient, measuring attenuation profiles along rays. These projection data are reconstructed using filtered back projection to produce images with improved contrast compared to radiography but some artifacts. Advances like spiral CT allow faster full-volume imaging but increase patient dose. CT provides anatomical detail but cannot replace modalities like MRI for all clinical needs.
CAT/CT scans use X-rays and computers to create cross-sectional images of the body. They can be used to diagnose many conditions by detecting abnormalities in soft tissues and bones. During a scan, an X-ray tube rotates around the patient, emitting a thin beam that is combined with readings from an array of detectors to construct images of the body's internal structures and organs. CT scans provide more detailed information than plain X-rays and have largely replaced conventional radiography for many diagnostic tasks.
The document contains questions and answers about various topics related to CT scans. It includes definitions and explanations of ring artifacts, HRCT techniques, image reconstruction methods, CT numbers, scintillation detectors, pixels, radiation profile width in CT collimators, CT number, resolution types, mass attenuation coefficient, parallel multi-hole collimators, low dose CT scans, CT guided biopsies, and CT artifacts. The document consists of questions from several students on technical aspects of computed tomography imaging.
Patient data acquisition and treatment verification.pptxJuliyet K Joy
1) Patient data acquisition involves obtaining 3D models from CT, MRI, or ultrasound scans to represent patient anatomy and tumours for treatment planning. CT numbers provide information on tissue density.
2) Treatment verification is important to ensure accurate radiation dose delivery and can involve portal films, electronic portal imaging, or cone-beam CT to check patient positioning.
3) Cone-beam CT acquires multidirectional x-ray images using on-board imaging systems to reconstruct 3D volumetric images for treatment guidance and avoiding critical structures.
This document discusses oncology imaging techniques. It begins by introducing advances in diagnostic imaging that allow visualization of macroscopic disease. It then summarizes key aspects of several major imaging modalities used in oncology, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and conventional radiography. For each modality, it describes the basic imaging principles, contrast mechanisms, applications in oncology, and considerations for clinical interpretation.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Basic physics of multidetector computed tomography ( CT Scan) - how ct scan works, different generations of ct, how image is generated and displayed and image artifacts related to CT Scan.
This document provides an overview of computed tomography (CT) and magnetic resonance imaging (MRI). It discusses the history and development of CT from the early 1970s to present day, including the evolution from first to fifth generation CT scanners. Key aspects of CT technology covered include the basic principles, components like the x-ray tube and detectors, and types of scans like conventional tomography and cone beam CT. The document also briefly introduces magnetic resonance imaging.
The document provides an overview of the basic principles of CT scanning. It discusses key differences between radiography and CT imaging, including that CT produces cross-sectional images without overlaying structures. It describes the CT scanning process where an X-ray beam passes through the patient and is measured to construct voxel values and pixels. CT numbers represent attenuation coefficients measured in Hounsfield units. The document also covers topics like polychromatic beams, volume averaging effects, raw vs image data, and different scan modes like step-and-shoot and helical scanning.
Computed Tomography and Spiral Computed Tomography JAMES JACKY
1. Computed Tomography / Spiral Computed Tomography
2. Clinical and Principle Operation of Computed Tomography
3. Law and Regulation in Malaysia
4. Radiation Dose
Lecture 3 & 4 anam sanam chick ldkfdlsfldfjdlsjfdlks .pptxfaiz3334
Computed tomography (CT) scans create cross-sectional images of the body by using X-rays and computer processing. An X-ray tube rotates around the body and produces multiple images from different angles, which are used to reconstruct cross-sectional slices using back projection. These slices can be combined to create 3D images. CT scans provide more detailed images than basic X-rays due to their ability to distinguish between different tissue densities and visualize structures throughout the body.
Computed tomography (CT) provides cross-sectional images of the body using X-rays. CT has evolved through several generations with advances in technology. Modern multi-detector CT allows acquisition of multiple slices simultaneously, reducing scan time. Helical or spiral CT involves continuous table movement and X-ray rotation, allowing whole organ or body coverage with minimal artifacts. Pitch relates the table speed to beam width and affects radiation dose and anatomic coverage. CT has advantages over conventional radiography including better contrast resolution and ability to distinguish between tissues.
Computed tomography (CT) uses rotating X-rays and computer processing to create cross-sectional images of the body. CT provides advantages over conventional radiography like distinguishing between tissues with similar densities and detecting differences as small as 0.5% contrast. Modern CT systems use multiple detector rows to acquire multiple slices simultaneously during each rotation, improving coverage and reducing scan time. Advanced techniques like multiplanar reformation and 3D rendering provide additional diagnostic information from CT images. Artifacts can arise from factors like the helical acquisition and differences between detector rows.
Computed tomography (CT) uses computer-processed X-rays to create cross-sectional images of the body. CT works by rotating an X-ray tube and detectors around the patient, acquiring multiple transmission measurements at different angles to reconstruct a 3D image. Image reconstruction involves algorithms like back projection and filtered back projection that use the transmission data to calculate the attenuation coefficients of different tissues and generate tomographic images representing slices of the body. CT numbers, measured in Hounsfield units, provide standardized values related to tissue density and visibility.
its about the CT scan and generations in the form of PPT explaining each of first generation , second generation, third generation, fourth generation, fith generation and sith generation
This document discusses various types of artifacts that are commonly encountered in clinical CT imaging. It describes ring artifacts, noise, beam hardening, scatter, motion artifacts, cone-beam artifacts, and metal artifacts. For each type of artifact, it explains the potential causes, appearance, and techniques for reducing the artifacts, such as increasing mAs, iterative reconstruction methods, and dual energy CT. Modern scanners have implemented various corrections but artifacts still occur and understanding their causes is important for accurate image interpretation.
This document provides information about computerized tomography (CT) scans. It defines CT scanning as a medical imaging method that generates 3D images of internal organs from a series of 2D X-ray images taken around a single axis of rotation. The history section describes how the first commercially viable CT scanner was invented in the 1970s in the UK and how subsequent innovations improved scanning speed and image quality. The document also summarizes different generations of CT scanners and their technical specifications.
Computed tomography (CT scan) is a medical imaging procedure that uses computer-processed X-rays to produce tomographic images or 'slices' of specific areas of the body. These cross-sectional images are used for diagnostic and therapeutic purposes in various medical disciplines.
Physical principle of Computed Tomography (Scanning principle & Data acquisit...ThejaTej6
Computed tomography (CT) uses x-rays and computer processing to produce cross-sectional images of the body. CT scanners are composed of an x-ray tube, detectors, and a rotating gantry. During a scan, the gantry rotates around the patient as they pass through, emitting a narrow x-ray beam and detecting the transmitted x-rays. The detected data is used to construct tomographic images, or slices, of the body. CT images provide more detailed information than conventional x-rays by measuring the attenuation of x-rays through tissues.
CT scanners produce cross-sectional images of the body by using X-rays from different angles to reconstruct tomographic slices. CT scanners rotate an X-ray tube and detector array around the patient, measuring attenuation profiles along rays. These projection data are reconstructed using filtered back projection to produce images with improved contrast compared to radiography but some artifacts. Advances like spiral CT allow faster full-volume imaging but increase patient dose. CT provides anatomical detail but cannot replace modalities like MRI for all clinical needs.
CAT/CT scans use X-rays and computers to create cross-sectional images of the body. They can be used to diagnose many conditions by detecting abnormalities in soft tissues and bones. During a scan, an X-ray tube rotates around the patient, emitting a thin beam that is combined with readings from an array of detectors to construct images of the body's internal structures and organs. CT scans provide more detailed information than plain X-rays and have largely replaced conventional radiography for many diagnostic tasks.
The document contains questions and answers about various topics related to CT scans. It includes definitions and explanations of ring artifacts, HRCT techniques, image reconstruction methods, CT numbers, scintillation detectors, pixels, radiation profile width in CT collimators, CT number, resolution types, mass attenuation coefficient, parallel multi-hole collimators, low dose CT scans, CT guided biopsies, and CT artifacts. The document consists of questions from several students on technical aspects of computed tomography imaging.
Patient data acquisition and treatment verification.pptxJuliyet K Joy
1) Patient data acquisition involves obtaining 3D models from CT, MRI, or ultrasound scans to represent patient anatomy and tumours for treatment planning. CT numbers provide information on tissue density.
2) Treatment verification is important to ensure accurate radiation dose delivery and can involve portal films, electronic portal imaging, or cone-beam CT to check patient positioning.
3) Cone-beam CT acquires multidirectional x-ray images using on-board imaging systems to reconstruct 3D volumetric images for treatment guidance and avoiding critical structures.
This document discusses oncology imaging techniques. It begins by introducing advances in diagnostic imaging that allow visualization of macroscopic disease. It then summarizes key aspects of several major imaging modalities used in oncology, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and conventional radiography. For each modality, it describes the basic imaging principles, contrast mechanisms, applications in oncology, and considerations for clinical interpretation.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
MATATAG CURRICULUM: ASSESSING THE READINESS OF ELEM. PUBLIC SCHOOL TEACHERS I...NelTorrente
In this research, it concludes that while the readiness of teachers in Caloocan City to implement the MATATAG Curriculum is generally positive, targeted efforts in professional development, resource distribution, support networks, and comprehensive preparation can address the existing gaps and ensure successful curriculum implementation.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
1. The structures in a CT image are represented by
varying shades of gray.
The creation of these shades of gray is based on the
attenuation (degree to which a beam is reduced).
An x-ray photon may pass through a structure,
may be scattered(redirected) by a structure,
absorbed by a given structure in varying amounts,
depending on
- the strength (average photon energy) of the x-ray
beam
- the characteristics of the structure in its path.
2. X-ray photons that pass through objects are
represented by a black area on the image.
These areas on the image are commonly
referred to as having low attenuation.
An x-ray beam that is completely absorbed by
an object cannot be detected; the place on the
image is white and the object is said to have
high attenuation.
3. The number of the photons that interact
depends on the thickness, density, and atomic
number of the object that the beam is passing
through.
Density can be defined as the degree to which
matter is crowded together, or concentrated.
The number of photons that interact increases
with the density, thickness, and atomic number
of the object
4. The amount of the x-ray beam that is scattered
or absorbed per unit thickness of the absorber
is expressed by the linear attenuation
coefficient, represented by the Greek letter μ.
For example, if a 125-kVp x-ray beam is used,
the linear attenuation coefficient for water is
approximately 0.18/cm, meaning that about
18% of the photons are either absorbed or
scattered when the x-ray beam passes through
1 cm of water
5. If the kVp is kept constant, the linear
attenuation coefficient will be higher for bone
than it would be for lung tissue.
That is, bone attenuates more of the x-ray beam
than does lung, allowing fewer photons to
reach the CT detectors.
this results in an image in which bone is
represented by a lighter shade of gray than that
representing lung
6. Differences in linear attenuation coefficients
among tissues are responsible for x-ray image
contrast.
In CT, the image is a direct reflection of the
distribution of linear attenuation coefficients
7. metallic objects and bone are represented on
the CT image as white areas.
Air (gas) has very low density, so it has little
attenuation capacity.
Air-filled structures (such as lungs) are
represented on the CT image as black areas.
To differentiate an object on a CT image from
adjacent objects, there must be a density
difference between the two objects.
8. An oral or intravenous administration of a
contrast agent is often used to create a
temporary artificial density difference between
objects.
9. In CT we are able to quantify the beam
attenuation capability of a given object.
Measurements are expressed in Hounsfield
units (HU), named after Godfrey Hounsfield,
one of the pioneers in the development of CT.
These units are also referred to as CT numbers.
Hounsfield units quantify the degree that a
structure attenuates an x-ray beam
10. Hounsfield arbitrarily assigned distilled water
the number 0
He assigned the number 1000 to dense bone
and −1000 to air.
Objects with x-ray beam attenuation less than
that of water have an associated negative
number.
Substances with an attenuation greater than
that of water have a proportionally positive
Hounsfield value
11. Using the system of Hounsfield units, a
measurement of an unknown structure that
appears on an image is taken and compared
with measurements of known structures. It is
then possible to approximate the composition
of the unknown structure
12. In general, the smaller the object being
scanned, the thinner the CT slice required.
As an example lung nodules; the chest is sliced
and examined , some slices contain nodules
and others do not.
If the slices are thick, it increases the possibility
that even though a given slice contains a
nodule, it will be obscured by the normal lung
tissue. If the slices are thin, the likelihood of
missing a nodule decreases, but the total
number of slices increases.
13. Thinner slices result in a higher radiation dose
to the patient.
In addition, if the area to be scanned is large, a
huge number of slices are produced.
Scanning procedures are designed to provide
the image quality necessary for diagnosis at an
acceptable radiation dose
14. If the structures being investigated are very small
(coronary arteries) and the region to be scanned is
not extensive (the heart versus the entire
abdomen), then slice thickness can be quite thin.
Conversely, scan protocols that span a longer
anatomic region (such as the abdomen and pelvis)
typically use a slice thickness of 5 to 7 mm.
In addition, spiral-scanning techniques have
allowed options for using data sets to
retrospectively adjust the slice thickness when
circumstances dictate.
15. The terms scan data and raw data are used
interchangeably to refer to computer data
waiting to be processed to create an image.
The process of using the raw data to create an
image is called image reconstruction.
Once raw data have been processed so that
each pixel is assigned a Hounsfi eld unit value,
an image can be created.
16. The reconstruction that is automatically
produced during scanning is often called
prospective reconstruction.
The same raw data may be used later to
generate new images. This process is referred
to as retrospective reconstruction.
17. Step-and-Shoot Scanning:
The scanning systems of the 1980s operated
exclusively in a “step-and-shoot” mode. In this
method:
1) the x-ray tube rotated 360° around the patient to
acquire data for a single slice,
2) the motion of the x-ray tube was stoped while the
patient was advanced on the CT table to the location
appropriate to collect data for the next slice,
3)Steps one and two were repeated until the desired
area was covered.
18. The step-and-shoot method was necessary
because the rotation of the x-ray tube entwined
the system cables, limiting rotation to 360°.
Consequently, gantry motion had to be
stopped before the next slice could be taken,
this time with the x-ray tube moving in the
opposite direction so that the cables would
unwind
19. Many technical developments allowed for the
continuous acquisition scanning mode most
often called spiral or helical scanning.
Key among the advances was the development
of a system that eliminated the cables and
thereby enabled continuous rotation of the
gantry.
This, in combination with other improvements,
allowed for uninterrupted data acquisition that
traces a helical path around the patient
20. Anterior and ventral refer to movement forward
Posterior and dorsal --the back surface of the body.
Inferior and caudal –down
Superior or cranial or cephalic toward the head
(up)
Lateral refers to movement toward the sides of the
body.
Medial refers to movement toward the midline of
the body
Distal (away from) or towards the end of an
extremity and proximal (close to)near a point
21.
22. CT scanners are similar in that they consist of a
scanning gantry, table, x-ray generator,
computer system, operator’s console, and
physician’s viewing console
The process includes data acquisition, image
reconstruction, and image display.
23. ▪ Components are mounted on a rotating scan frame.
▪ Gantries vary in total size as well as in the diameter of the
opening, typically 70 to 90 cm.
▪ The CT gantry can be tilted either forward or backward as
needed with the degree of tilt ±15° to ±30° is usual.
▪ The gantry also includes a laser light that is used to position
the patient within the scanner.
▪ Control panels located on either side of the gantry opening
allow the technologist to control the alignment lights, gantry
tilt, and table movement.
▪ In most scanners, these functions may also be controlled via
the operator’s console.
▪ A microphone is embedded in the gantry to allow
communication between the patient and the technologist
throughout the scan procedure
24.
25. Early CT scanners used recoiling system cables
to rotate the gantry frame.
Current systems use electromechanical devices
called slip rings.
Slip rings use a brushlike apparatus to provide
continuous electrical power and electronic
communication across a rotating surface.
They permit the gantry frame to rotate
continuously, eliminating the need to
straighten twisted system cables
26. High-frequency generators are currently used in CT.
They are small enough so that they can be located
within the gantry
Generators produce high voltage and transmit it to the
x-ray tube. The power capacity of the generator is
listed in kilowatts (kW).
The power capacity of the generator determines the
range of exposure techniques (i.e., kV and mA settings)
available on a particular system.
CT generators produce high kV (generally 120–140 kV)
to increase the intensity of the beam, which will
increase the penetrating ability of the x-ray beam and
thereby reduce patient dose.
27. Compensating filters are used to shape the x-ray
beam.
They reduce the radiation dose to the patient and
help to minimize image artifact.
The radiation beam emitted by CT x-ray tubes is
polychromatic. Filtering the x-ray beam helps to
reduce the low energy range of x-ray photons.
These photons are absorbed by the patient,
therefore they do not contribute to the CT image
but do contribute to the radiation dose to the
patient.
28. The compensating filters used in CT are often
called bowtie filters because of their shape.
The filter is thinnest at the central ray of the beam
and thicker toward the edges of the fan beam.
Thus the thinnest part of the filter is in line with
the thickest path length through the patient’s body
as the gantry rotates, and the thicker part of the
filter is in line with the thinner peripheral
anatomy. The filter partially compensates for the
patient’s body thickness contour
The bowtie filter is selected by the scanner and
switched into the beam path automatically based
on the scan setup chosen by the operator.
29. A beam composed of different photon energies passing through one half-
value layer of absorber will have a lower intensity (fewer photons) and a
higher average energy in the transmitted beam, because the low-energy
photons are more easily absorbed and the high-energy photons are better able
to penetrate the absorber.
30. Collimators restrict the x-ray beam to a specific
area, thereby reducing scatter radiation.
Scatter radiation reduces image quality and
increases the radiation dose to the patient.
Reducing the scatter improves contrast
resolution and decreases patient dose.
Collimators control the slice thickness by
narrowing or widening the x-ray beam
31. The source collimator is located near the x-ray
source.
Because it acts on the x-ray beam before it
passes through the patient it is sometimes
referred to as pre-patient collimation.
The source collimator affects the slice thickness.
In MDCT systems, slice thickness is also
influenced by the detector element
configuration.
32.
33.
34. Some CT systems also use pre-detector
collimation.
This is located below the patient and above the
detector array.
Because this collimator shapes the beam after it
has passed through the patient it is sometimes
referred to as post-patient collimation.
The primary functions of pre-detector
collimators are to ensure the beam is the proper
width as it enters the detector and to prevent
scatter radiation from reaching the detector.
35. As the x-ray beam passes through the patient it
is attenuated to some degree.
To create an x-ray image we must collect
information regarding the degree to which
each anatomic structure attenuated the beam.
We use detectors to collect the information
The detector array comprises detector elements
situated in an arc or a ring, each of which
measures the intensity of transmitted x-ray
radiation along a beam projected from the x-
ray source to that particular detector element
36. Detectors can be made from different substances,
each with their own advantages and
disadvantages.
The optimal characteristicsof a detector are as
follows:
1) high detector efficiency, defined as the ability of
the detector to capture transmitted photons and
change them to electronic signals;
2) low, or no, afterglow, defined as a brief, persistent
flash of scintillation that must be taken into
account and subtracted before image
reconstruction;
3) high scatter suppression;
4) high stability, which allows a system to be used
without the interruption of frequent calibration
37. Detector efficiency can be measured as
- geometric efficiency, defined as the amount of
space occupied by the detector collimator plates
relative to the surface area of the detector;
- Absorption efficiency refers to the number of
photons absorbed by the detector and is dependent
on the physical properties of the detector face (e.g.,
thickness, material)
- Response time is the time required for the signal
from the detector to return to zero after
stimulation of the detector by x-ray radiation so
that it is ready to detect another x-ray event
38. The relative
placement, shape, and
size of the detectors
affect the amount of
scatter radiation that
reaches the image.
A deep, narrow
detector design will
accept less scatter
than short, wide
detectors Low scatter acceptance is desirable
39. Solid-state detectors are also called scintillation
detectors because they use a crystal that fluoresces
when struck by an x-ray photon
These detectors use crystals composed of fast
scintillator ceramics such as cadmium telluride
and gadolinium oxysulfide.
The crystals convert x-rays to light pulses whose
intensity is proportional to the total energy of
photons striking the crystal.
The light is converted to electrical current which in
turn is detected as digital data for use by the
reconstruction system.
40. Detectors are separated using spacing bars. This
allows the detectors to be placed in an arc or circle.
Ideally, detectors should be placed as close
together as possible, so all x-rays are converted to
data.
The size of the detector opening is called the
aperture.
A small detector is important for good spatial
resolution and scatter rejection.
Maximum utilization and small aperture are
desirable
41. Detector arrays continue to grow as individual
detector elements remain small, providing
small pixel size with ever-greater anatomic
coverage.
Common detector arrays accommodate
scanning of 80 to 160 mm of coverage in a
single tube rotation, with resolution of 0.5 to
0.6 mm, so that entire sections of patient
anatomy can be captured in a single revolution
of the CT scanner’s rotating frame, taking less
than 1 second.
42. Computed Tomography for Technologists. Louis
E. Romans
Principles of CT: Multislice CT, Lee W. Goldman,
Journal of Nuclear medicine Technology
Scan Acquisition Settings - Trade Offs Between
Speed, Resolution and Dose, James M. Kofler,
Ph.D., Radiology, Mayo Clinic Rochester,
Minnesota
http://xrayphysics.com/ctsim.html
Radiologykey.com
Radiopedia.org