radiation
X-Ray Tube
Damage to x-ray tubes can occur if unnecessary anode prep times are used and repeated preparation of the tube before exposures occur. Damage to x-ray tubes/shorten their lifespan can occur if unnecessary anode prep times are used and repeated preparation of the tube before exposures occur.
Image receptor
Digital radiography & Computed Radiography cassette and cassette-less systems Image receptor intercepts the x-ray photons that exit the patient
Digital Cassette-less Systems
Direct Capture Amorphous selenium (a-Se) Resolution X-ray photons are absorbed by the coating material and immediately converted electric signal The DR plate has a radiation conversion material or scintillator made of amorphous selenium (a-Se) The Resolution of digital images are determined by the individual size of each pixel Dc can capture 1 million + pixels and be converted into an image in less than 1 second
Pregnant Students
Dose limit for a declared pregnant woman is .5 rem (5 mSv) NCRP also recommends a limit of .05 rem (.5 mSv) per month
Organizational Chart Changes
Economic Hardships have forced hospitals to reorganize/restructure. Obama Care: Accountability!!! Focus on Quality or Patient Safety: Undergoes a Cultural Revolution Social and economic conditions of the late 1980s and early 1990s caused vast changes in health care organizations, forcing them to alter their organizational structures. Development of new technologies, changes in reimbursement, and a greater focus on utilization review processes contributed to a decline in inpatient use during the 1980s.
Scatter Radiation
Non-diagnostic radiation. along the way an x ray photon may interact with the body's matter in such a way that the resulting photon continues its travel in a different direction.
External Agencies
Nuclear Regulatory Commission (NRC) NRC regulates the use of ionizing radiation including medical and nuclear applications. These regulating groups conduct inspections and levy fines for noncompliance with regulations, which vary from state to state.
Radiation Monitoring
Optically Stimulated Luminescence (OSL) dosimeter The OSL dosimeter comprises of a strip of aluminum oxide , copper filter, tin filte, and imaging filter The device is sealed in a tamper proof plastic blister pack Laser light stimulates the aluminum oxide causing it to become luminescent in proportion to the amount of radiation exposure, which determines the occupational worker's exposure
Indirect Action
***ON TEST*** Indirect action of ionizing radiation is most prevalent and most harmful to the human body
Early Effects of Radiation Exposure
1) Prodormal Acute radiation syndrome has 3 stages Prodormal stage- (NVD) nausea-vomiting-diarrhea
Reciprocity
100 mA X 1/10 = 10 mAs 200 mA X 1/20 = 20 mAs 300 mA X 1/30 = 30 mAs Reciprocity- any combination of mA and time producing equivalent exposures and therefore densities
Early Effects of Radiation Exposure
2) Latent Period Latent period- the organism feels biological changes during this period
Two Types of Radiation
Natural or Background Radiation Human-made Radiation
X-Ray Interacting with Matter
2) Photoelectric Interaction The atom having lost an electron is positively charged and referred to as the photoelectron In this interaction all of the photon's enegy is absorbed by the atom Because the energy is completely absorbed, this constitutes the GREATEST HAZARD to patients in diagnostic radiography
X-Ray Interacting with Matter
3) Compton Scattering Compton scattering is when the x-ray photon strikes a target atom and uses a portion of its energy to eject an outer shell electron The remaining energy proceeds in a different direction This interaction is important because Compton scatter produces most of the worker's exposure radiation
Early Effects of Radiation Exposure
3) Manifest Stage Manifest stage- final stage, the organism feels full effects of the exposure, leading to recovery or death- (4th step)
X-Ray Interacting with Matter
4) Pair Production-negatron and positron Pair Production occurs whenever there is 1.02 Mev of energy. Diagnostic radiology does not have energies that high. However, radiation therapy does. Typical radiation therapy machines use energies in the 6-18 Mev range.
Standards for Regulation of Exposure
ALARA -Studies indicate an individual's dose should be kept as low as resonably achievable -annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem) -formual goes 5(n-18), N=age of worker, or 1 rem x N, 1 rem = 10 mSv
Control Console
Allows the radiographer to turn the system on and off, select the x-ray exposure factors, initiate and terminate the exposure, and provide an audible and visual indication of x-ray exposure. All systems will allow the radiographer to turn the system on and off, select the x-ray exposure factors, initiate and terminate the exposure, and provide an audible and visual indication of x-ray exposure.
Radiation Sources
Also called background radiation Background radiation comes from the sun and other planetary bodies and naturally occurring radioactive substances present on earth (uranium and radium) Occurs
X-Ray Tube Support Design
Chest radiographs and upright abdominal studies are performed using upright cassette holder or Bucky. Chest radiographs and upright abdominal studies are performed using upright cassette holder or Bucky.
Additional Protction
Filtration X-ray beam filtration material in the path off the x-ray beam absorbs the low energy x-rays that only add to the patient's entrance dose
Shape Distortion
If the object of interest is superimposed on another object, the resulting image is difficult to elevate. Rotate or oblique the body so that the object can be projected free from the interference of the overlying object
Radiosensitivity of Cells
In 1906, these researchers determined that cells are most sensitive to radiation during division and structure and function Rapidly dividing and undifferentiated cells demonstrate the injury sooner
Primary Beam
Kiloelectron volts (keV) The x-ray beam ,measured in keV, is directed toward the patient through a window in the tube The x-ray beam ,measured in keV, is directed toward the patient through a window in the tube
Early Effects of Radiation Exposure
Last step after manifest stage
Image Receptor Systems
Latent image radiograph The image that is stored in the emulsion until it is processed, this is the invisible image, aka the latent image Radiograph- the image produced by x-ray photons on a piece of film
Shielding
Lead aprons lead aprons protect the user from scattered and secondary radiation Demonstrate the photoelectric effect
Image Production
Milliampere-seconds (mAs) Quantity Quantum mottle or noise Parameter that controls the amount of x-radiation produced by the x-ray tube, milliamps (mA) multiplied by seconds Milliamps-the measure of electrical current passing through the x-ray tube, it also controls the IR exposure Time <seconds> duration of exposure, its expressed in milliseconds or fractions Quantum mottle or noise- when insufficient light is emitted form the phosphors, it produces an image that grainy
Hospital Mission Statement
Mission Statement: The driving and guiding force that outlines the organization's reason for existence and defines what should be done and how it should be done Helps keep an Organization focused on the goals ...Provide service in terms of the intended recipients of service, the type of care or services, and the level of quality and cost expected...
Computed Radiology
Photostimulable Phosphor Technology Commonly referred to as computed radiography, PSP imaging uses a reusable imaging plate. PSP detectors capture the energy of the remnant beam and store it for a period of time in "electron traps." These electron traps represent the latent image. PSP Technology the x-ray exposure is contained in "Electron Traps" in the phosphor layer
PACS
Picture archive and communication systems (PACS) became widely accepted as a digital alternative to film-screen imaging devices in the late 1990s. The most noted benefit of a PACS is that it allows a health care provider to access digital imaging information anytime and anywhere care is being provided.
Radiation Types
Primary radiation Remnant radiation Scatter Radiation Primary - The beam of photons that exit the x-ray tube and hit the patient's body , the amount of photons lessens as they pass through matter Remnant- the resulting beam that exits from the patient SCATTER- photons that interact with the body's matter and travel in a different direction
ATTENUATION
Primary radiation is changed as it travels through the patient, the beam attenuates differently depending upon the material it comes in contact with (EX bone, tissue, cartilage)
Units of Measure
Radiation Absorbed Dose (rad) Gray Rad measures the amount of energy absorbed in any medium 100 ergs of energy absorbed in 1 g of absorbing material 1 Gy = 100 rad In the SI system, rad has been replaced the gray (Gy) [1 J (joule) of energy absorbed in 1 kg of material],
Units of Measure
Radiation Equivalent Man (rem) Rem measures the effect of alpha particles, neutrons, and beta particles upon living tissue, it accurately expresses the biologic response of exposed individuals to the same quantity of differing radiations Quality factor varies upon radiation being used X-rays) 1 rad x 1 = 1 rem Fast neutrons ) 1 rad x 10 = 10 rem, neutrons are 10 times as biologically damaging as x-rays when their dose equivalents are compared Rem has been replaced by sievert (Sv) in SI system 1 Sv = 100 rem
Xrays always come with biological risks
Radiographer has to use sound judgment Always try to minimize the quantity of radiation to patient and others
Image Production
Radiolucent- material allowing x-rays to pass through relatively easily, like light going through glass, or air in the body Radiopaque- materials not easily traversed by x-ray photons, like tinted glass or bone
Fluoroscopic Examinations
Real-time images are created dynamic action of the human body showing internal activities and processes Known as Fluoroscopy gastrointestinal (GI) movement and structure, blood vessels, genitourinary functionality, and joint mobility For study of the dynamic action of the human body, real-time images are created, showing internal activities and processes. Known as fluoroscopy, this method is used to create images that are continuous and demonstrate vital processes such as gastrointestinal (GI) movement and structure, blood vessels, genitourinary functionality, and joint mobility, just to mention a few.
jrcert
Requires students to have a mandetory 36 competencies minimum 6 general patient care 15-30 elective competencies
X-Ray production requirements
Source of electrons Force to move them rapidly An object to stop the movement rapidly
Guidelines
Students must adhere to ARRT standards and HIPPA rules Students must follow appearance guidelines Pregnancy- female students must declare their pregnancy to the program official in writing
For study of the dynamic action of the human body, real-time images are created, showing internal activities and processes. Known as fluoroscopy, this method is used to create images that are continuous and demonstrate vital processes such as gastrointestinal (GI) movement and structure, blood vessels, genitourinary functionality, and joint mobility, just to mention a few. Manipulation of Fluoroscopic Equipment
The C-Arm is typically used to perform Fluoroscopy in Surgery C-ARM is used in Surgery
didactic
The classroom portion of the curriculum
Collimator Assembly
The collimator controls the size and shape of the x-ray field coming out of the x-ray tube. Attached directly below the x-ray tube is an x-ray beam-limiting device called a collimator (Fig. 8-2). The collimator controls the size and shape of the x-ray field coming out of the x-ray tube. The radiographer determines the size of the x-ray field by adjusting two controls on the front or sides of the collimator, one for the length and one for the width of the rectangular x-ray field.
Milliampere-Seconds
The milliamperage indicates the amount of current supplied to the x-ray tube. The seconds indicates the x-ray exposure time. The milliamperage indicates the amount of current supplied to the x-ray tube. The product of mA and Seconds creates mAs otherwise known as the quantity of the beam.
Milliampere-seconds (mAs)
The parameter that controls the amount of x-radiation produced by the x-ray tube; it is the product of milliamperage (mA) multiplied by seconds. It dorectly controls the quantity of x-ray photons produced. Milliamperage is a measure of the electrical current passing through the x-ray tube.
Kilovolt Peak
The penetration power of an x-ray beam is determined by its voltage and is expressed as kilovolt peak (kVp). As kVp increases, so does penetration. Known as Quality of the Beam. Can also affect quantity The penetration power of an x-ray beam is determined by its voltage and is expressed as kilovolt peak (kVp). As kVp increases, so does penetration. Known as Quality of the Beam.
Milliampere-Seconds
The product of mA and seconds creates mAs otherwise known as the quantity of the beam. Use shortest exposure time to minimize patient motion. Shortest exposure time minimizes patient motion
Radiology Organization
The radiology department has the same focus on the hospital mission to serve patients and has needs similar to those of the larger organization Broken into different modalities The radiology department has the same focus on the hospital mission to serve patients and has needs similar to those of the larger organization—personnel, information, supplies, equipment, space, electricity, plumbing, and maintenance.
exit or Remnant Radiation
The resulting beam that is able to exit from the patient
X-Ray Tube Support Designs
The tube stand or the overhead tubecrane assembly allows the x-ray tube to be moved in different directions The component that supports and permits the x-ray tube to be moved in different directions
Pocket Dosimeters
These are used when an immediate reading of occupational dose is desired
2) Thermionic Emission
Tungsten filament Filament is composed of thoriated tungsten for better durability
4 Needs to Produce X-Rays
Vacuum tube Filament Vacuum tube removes all air so that gas will not interfere with the production of x-ray Filament provides source of electrons
4 Needs to Produce X-Rays
Voltage Target Voltage accelerates the electrons by electrically charging them The target or patient stops the electrons, then x-ray photons are produced Less than 1% of this production is actual x-ray, the remaining 99% is heat
Anode
When electrons exit the cathode and hit the anode, they convert into x-rays and heat
X-Ray Tube
X-Ray Tube produces radiation, is made of Pyrex glass (to withstand heat), and it's primary components are the Anode and the Cathode. The x-ray tube is the part of the radiographic system that produces the x-rays. It is made of Pyrex glass and is encased in a sturdy metal housing, with large high-voltage electrical cables attached at each end. The x-ray tube's primary components are the anode and the cathode
1) Source of Electrons
X-ray tube The tube is composed of a cathode (negative terminal) and an anode (positive terminal), enclosed in a special glass envelope to maintain the vacuum seal necessary for x-ray production
Source to image distance (SID)
distance between the point of x-ray emission in the x ray tube (the focal spot) and the image receptor.
Kivovolt peak (kVp)
is a measure of the electrical pressure (potential difference) forcing the current through the tube. it controls penetrating ability of the beam and primarily affects the quality but also the quantity of the x-ray photons produced.
Primary radiation
the beam of photons before it interacts with the patients body
Attenuation
the process by which the nature of the primary radiation is changed, partially absorbed or scattered as it travels through the patient.
