CRT04104 Radiology and Imaging Equipment

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Film Cassette CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Film Cassette using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic FILM CASSETTES FILM CASSETTE X-RAY CASSETTES FEATURE OF THE IDEAL CASSETTE Cassette design and construction should include CONSTRUCTION Back of the cassette : A large number of synthetic materials are used in the construction of the cassette to make them lightweight Metal (e.g. aluminium), plastic laminate or carbon fibre are material commonly used in cassette front construction Materials used in cassette construction TYPES OF X-RAY CASSETTE ii) Double screen cassettes: Similarly, films which are separated by 10mm of spacing materials will bear images of separate body layers 10 mm apart. CASSETTES AND AUTOMATIC EXPOSURE DEVICES CARE OF X-RAY CASSETTE CASSETTE MAINTANANCE LOADING AND UNLOADING CASSETTE OTHER TYPES OF CASSETTE FILM CASSETTE FILM CASSETTES This is a container for exposed & unexposed film They are used to hold x-ray film and intensifying screen in close contact and uniformity with one another FILM CASSETTE A cassette is a light proof rigid holder that contains screens and film Cassettes are usually hinged (latches) on one side and can be opened from the other side. The side which is having the latches is the back side and other side facing the patient is called front side. The front side is made of material of low atomic number, like plastic or carbon fiber. This is to maximize the transmission with low attenuation. Carbon fiber (Z = 6) absorbs only 50% of X-rays compared to aluminum. Cassette with carbon fiber can be operated with low radiographic techniques, resulting in lesser patient dose. The back side is usually made of heavy metals (lead), having high atomic number, to minimize back scatter. CASSETTE X-RAY CASSETTES FUNCTIONS Protect film from exposure to light Protect film from bending and scratching during use. Contain intensifying screens, keeps film in close contact to screen during exposure. Exclude dust and dirt from the sensitive screen FEATURE OF THE IDEAL CASSETTE Strong and rigid to withstand daily wear and tear Lightweight to facilitate easy handling and carrying Easy to open and close, under low light conditions The cassette front must provide minimal beam attenuation be of uniform thickness and hence on irregularities which might be visible on radiograph No sharp edges and corners which might injure patients or staff Have a strong aperture for use in patient’s identification system Cassette design and construction should include feature contributing to close contact between film and screen e.g. Foam sponges Some similar materials covered front providing warmth to touch Should be available in range of film size Be sold with same guarantee of quality CONSTRUCTION Consist of a FRONT and BACK hinge at one long edge Attached to the inside back of the cassette is a thin sheet of lead foil and attached to a plastic foam pressure pad and an intensifying screen Front of the cassette : Cassette well containing the front intensifying screen and short lead blocker for patient identification May incorporate an additional foam pressure pad underneath the front intensifying screen Back of the cassette : May incorporate, in one corner, a recess and sliding aperture for with patient identification camera Locking methods e.g. spring clips, sliding locking bars, all serves to exclude all light when in locked position The foam pressure pad maintain close and uniform contact between the film and screen All internal metal or plastic surface are given a black coating in order to prevent the possibility of internal light reflection A large number of synthetic materials are used in the construction of the cassette to make them lightweight Cassette front Should be uniform in thickness and density and have no irregularities which might be made visible on the be made visible on the radiograph In order to minimize beam attenuation cassette front should confront the British standard (Bs 4302 1968) states that the cassette front, if metal, should have an Al equivalent of no more than 1.6 mm when used at 60 kVp or, if plastic, no more than 0.2mm Al equivalent. Materials used in cassette construction Metal (e.g. aluminium), plastic laminate or carbon fibre are material commonly used in cassette front construction All these material have the following advantages Light in weight Low beam absorption Strength and stiffness N/B The use of carbon fibre cassettes reduce patient dose significantly due to their lower beam attenuation Cassette front Materials used in cassette construction Cassette back: May be made of metal or plastic construction and lined with lead foil in order to protect film from radiation scattered backwards from a buck tray or other surface The BS recommendation states that it should have a lead equivalent of at least 0.12 mm when used with equipment operating at 150kV constant potential Cassette back Materials used in cassette construction Cassette fitting Clip or fastener – usually stainless steel Hinge metal or Plastic Pressure pad plastic foam sponge TYPES OF X-RAY CASSETTE (i) Single screen cassette : Have single intensifying screen and are designed to be used with single – sided emulsion film Their principal application is in mammography ii) Double screen cassettes: Have screen on both sides have intensifying screen on both sides and are designed to be used with double– sided emulsion film Used in general radiography TYPES OF X-RAY CASSETTE CURVED CASSETTE: There are of two types The first used when the necessary close object / cassette contact cannot be achieved with a conventional flat cassette e.g. intercondylar projections of the knee with the joint flexed The second used to obtain panoramic views of the mandible and maxilla in orthodontic radiography ( orthopantomography) Film Cassette (a) is used where the necessary close contact between object and cassette cannot be achieved with a conventional flat cassette, e.g. intcrcondylar views of the flexed knee joint; (b) is used to obtain panoramic views of the mandible (orthopantomography). CURVED CASSETTE TYPES OF

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 CRT04104 Radiology and Imaging Equipment Notes Browse 19 study topics in Radiology and Imaging Equipment, NTA Level 4, Semester 1. Imaging Modalities Care Of Radiology Equipments Equipment Cleaning Tube Warming And Calibration Equipment Knobs Electrical Gadgets and Plugs Accessories for Radiological Investigations Room Design Component of Conventional X-ray equipment and their function Dental Equipment Film Cassette Intro To Equipment Mains Voltage Compensation Radiology Equipment: Operating Principles Rectification 2Nd Module Rectifiers The high tension source What are the component of Conventional x ray machine X-ray Tube Stand ← PREVIOUS MODULENEXT MODULE →SEMESTER NOTESNTA LEVEL 4 NOTESALL NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE X-ray Tube Stand CRT04104 · Radiology and Imaging Equipment START READING NOTES Study X-ray Tube Stand using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. X-RAY TUBE STAND It is part of the x ray set which support the x ray tube so that it can be applied for radiological examinations TYPES OF TUBE STAND Floor x ray tube stand Floor to wall x ray tube stand Ceiling x ray tube stand Ceiling rails REQUEREMENTS OF X RAY TUBE STAND The x ray tube support should be adequately rigid so that vibration of x ray tube is avoided. All movements of the support and x ray tube about it should be smooth, unrestricted and easy to perform. It must be possible to make certain precise angulations of the x ray tube It must be possible to direct the x ray tube parallel to the floor as well as in a perpendicular direction The controls providing for the tube movements should be easily readily accessible. X-RAY TUBE STAND The x ray tube stand consists of a column of heavy gauge steel which is amounted on a carriage for movements between tracks on the floor and ceiling On the vertical column a cross- arm supports the x ray tube. The cross- arm can be moved up and down the column, at right angle to the column, and in the rotational motion about the vertical axis of the column. X-RAY TUBE STAND The x ray tube can be rotated up on the cross-arm and can be tilted about an axis parallel to itself. These movements made for the following excursion of x ray tube Longitudinal travel ( parallel to the x ray tube) Horizontal travel at right angle Vertical travel and down the column Rotation travel about the vertical column Rotation on an axis parallel to the cross- arm of 180 degree to 180 degree Rotation round the tube’s own long axis. ← PREVIOUS TOPICVIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE What are the component of Conventional x ray machine CRT04104 · Radiology and Imaging Equipment START READING NOTES Study What are the component of Conventional x ray machine using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Here are the key components of a conventional X-ray machine and their functions: X-ray Tube: Function: This is the heart of the machine. It generates X-rays by accelerating electrons from the cathode to the anode. High Voltage Generator: Function: Provides the extremely high voltage (typically tens to hundreds of kilovolts) needed to accelerate the electrons within the X-ray tube. Control Panel: Function: Allows the radiographer to adjust settings like: Kilovoltage Peak (kVp): Controls the energy and penetrating power of the X-rays. Milliamperage (mA): Controls the number of electrons flowing from the cathode, influencing the X-ray beam's intensity. Exposure Time: Determines how long the X-ray beam is produced. Collimator: Function: Restricts the size and shape of the X-ray beam, minimizing the area of the patient exposed to radiation. This reduces scatter radiation and improves image quality. Patient Table: Function: Supports the patient during the examination. It can be adjusted to various positions (e.g., upright, tilted) to obtain the desired image. Image Receptor: Function: Captures the X-ray image. This could be: Traditional X-ray film: (older technology) Digital detectors: (more modern, allowing for faster image acquisition and processing) Cooling System: Function: The X-ray tube generates a significant amount of heat during operation. The cooling system (often involving oil circulation) helps to dissipate this heat and prevent damage to the tube. Let me know if you'd like a more detailed explanation of any of these components! ← PREVIOUS TOPICNEXT TOPIC →VIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE The high tension source CRT04104 · Radiology and Imaging Equipment START READING NOTES Study The high tension source using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic COMPONENTS AND CONTROL IN X RAY CIRCUIT The x-ray tube circuit comprises the following components and controls:- The high tension source: CONTRUCTION OF A TRANSFORMER For an ideal transformer the induced voltage in each turn is the same. On combining the two equations we get:- WINDINGS Step-down transformer AUTO TRANSFORMER There is only one winding Filament Circuit The components in the filament circuit The Autotransformer; Contains an iron core and a single winding or wire, supplies power to the filament transformer. Filament Transformer mA selector The voltage stabilizer: Absorbs or cancels out any voltage fluctuation which may occur in the filament circuit. Control COMPONENTS AND CONTROL IN X RAY CIRCUIT 15-Nov-17 The x-ray tube circuit comprises the following components and controls:- The high tension source The kilo voltage control Filament circuit and milliamperage control Timer The mains supply, and The x-ray tube as shown in the diagram below The high tension source: The source of high voltage which is used to drive electrons fast across an x-ray tube is a high tension transformer. The high tension transformer transforms the voltage of the main supply up to the range of voltage from about 20,000 to 100,000 volts (20kV to 100kV). The function of high tension transformer is to transform the voltage from the main supply up to thousands of volts required to operate the x-ray tube. (step up transformer) The high tension source: Grounded metal box filled with oil electrical insulator Also contains rectifier circuit changes alternating current into direct current CONTRUCTION OF A TRANSFORMER Materials used are soft ion and copper wires. The soft ion core is wound with copper wire on it as indicated on the diagrams below:- The high tension source The step-up transformer has many numbers of turns in the secondary winding compared to the primary winding, while the step-down transformer has less number of turns on the secondary winding. For an ideal transformer the induced voltage in each turn is the same. Therefore the total primary voltage is the voltage in each turn multiplied by the number of turns. Thus: Vp = V x Np or Vp/Np = V Similarly for the secondary: Vs = V x Ns or Vs/Ns = V On combining the two equations we get:- Vp /Np = Vs/Ns By cross multiplication we get: Vs/Vp = Ns/Np WINDINGS The primary winding receives electricity from the mains supply. It has few number of turn compared to the secondary winding. It is shorter and thicker because carries very high current (it may be 200 Amps). The secondary winding supplies kilovoltage and mill amperes for the x-ray tube. Supplies power in form of low current at very high voltage. This is the reason to why it is made of thin wire. It is long compared to the primary winding. Step-down transformer This is a type of transformer steps down high volts to low volts e.g. the filament transformer. It steps down the mains voltage which used by the filament. This type of transformer has few number of turn on the secondary winding. AUTO TRANSFORMER Is the type of transformer which has one winding wound around a soft iron core. There is only one winding The primary and secondary circuits are in metallic connection with each other. This fact makes an auto transformer unsuitable for transforming high voltages from one value to another or for stepping up voltages to high values. Filament Circuit The circuit which supplies power to the filament of the x-ray tube X RAY TUBE FILAMENT CIRCUIT The components in the filament circuit An autotransformer mA Selector Filament transformer Voltage stabilizer Frequency compositor The Autotransformer; Contains an iron core and a single winding or wire, supplies power to the filament transformer. The step-down transformer; Decreases voltage from primary to the secondary coil and increases current in the same proportion. Has more turns in the primary than in the secondary coil. Used in the filament portion to increase current flow to the cathode. Filament Transformer Intended to lower voltage and increase current Allows for thermionic emission to occur at the filament Ultimately, provides the electrons necessary for x-ray production. Tube current measured in mA. The high tension source The mA selector: Used for selecting the amount of current flowing in the filament circuit by varying resistors. The amount of filament current determines how hot the filament wire gets.(More current more heat more electrons boiled off the filament wire Higher mA). mA selector Allows for adjusting of the filament current Precision resistors The voltage stabilizer: Absorbs or cancels out any voltage fluctuation which may occur in the filament circuit. It receives voltage from the autotransformer and supplies to the mill ampere selector. The space charge compensator: Compensates any selected low kilo voltage which will be less able to attract electrons out of the space charge The mA meter: Indicates the tube current Control Factor Electrical Device and Location in Circuit kVp Selection kVp Level Autotransformer (between incoming line and exposure switch) mA Selection Filament Current Variable resistor (in filament circuit between incoming line and step-down transformer) Time Selection Length of exposure Timer circuit (between exposure switch and step-up transformer) Rotor Switch Speed of rotating anode Stator (separate circuit from stator of anode motor) Exposure Switch Moment of exposure Switch (between autotransformer and timer circuit) Filament Circuit ← PREVIOUS TOPICNEXT TOPIC →VIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? 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DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Rectifiers CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Rectifiers using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic RECTIFERS SOLID-STATE RECTIFIER OR SEMI-CONDUCTORS HOW P-Type Silicon is created N Type Semiconductors Junction Barrier FORWARD BIAS. The positive and negative terminals of the bias battery are connected to P-type and N-type respectively Neutralizing ions on both sides of the barrier, decreases its width. REVERSE BIAS Rectifiers a) The collector is connected to high negative voltage with respect to base i.e. Vbc is very high. So the holes in emitter layer are attracted by negative terminal of Vbe and thus, they cannot cross the junction. NPN JUNCTIONS Note the following important points:- Emitter layer is heavily doped. It has largest number of charges (electrons). Forward Biasing Hence, we conclude that collector current (Ic) is the function of base current ADVANTAGE OF SOLD STATE HIGH TENSION RECTIFIERS OVER THERMIONIC DIODE VALVES RECTIFERS Thermionic diode valves Earlier rectifiers used Consists two electrodes and a glass envelope enclosing a vacuum Passes current through a vacuum in one direction and blocks any reverse flow Sold state rectifiers (semi conductors) Are modern rectifiers to thermionic diode valves Passes electrons through sold material as opposite to vacuum. SOLID-STATE RECTIFIER OR SEMI-CONDUCTORS SOLID- STATE RECTIFIER: Is a solid – state device that serves as an electronic rectifying element. It is made of a combination of P-Type layer and N-Type layer. HOW P-Type Silicon is created To make P-Type silicon, trivalent impurities such as Boron, Indium, Aluminum and Gallium are added or mixed with Silicon (Si). Covalent bond occurs between Silicon and the trivalent atoms. In process of bonding, a vacant hole is created within the covalent bond between one trivalent atom and a neighboring Silicon (Si) atom. The holes are considered to be positive charge carriers. Graphic Representation of P-Type silicon mixed with Boron. N Type Semiconductors If Pentavalent impurities such as phosphorus, arsenic, antimony, and bismuth is added to Silicon (Si) Valence electrons of phosphorus are locked up in covalent bond with valence electrons of four neighboring Silicon (Si) atoms The 5th valence electron of phosphorus atom does not find a binding electron and thus remains free to float. Junction Barrier When p-type and N-type are joined together, the electrons in the N material diffuse across the junction into the P material and fill some of the holes. At the same time, the holes in the P material diffuse across the junction into the N material and are filled by N material electrons. The loss of an electron from the N-type material created a positive ion in the N material, while the loss of a hole from the P material created a negative ion in that material. FORWARD BIAS. If an external voltage applied to a PN junction is call BIAS. A battery is used to supply bias to a PN junction and is connected so that its voltage opposes the junction field, it will reduce the junction barrier and, therefore, aid current flow through the junction. This type of bias is known as forward bias, and it causes the junction to offer only minimum resistance to the flow of current The positive and negative terminals of the bias battery are connected to P-type and N-type respectively The positive potential repels holes toward the junction where they neutralize some of the negative ions The negative potential repels electrons toward the junction where they neutralize some of the positive ions. Neutralizing ions on both sides of the barrier, decreases its width. This allows flow of electrons across the junction. REVERSE BIAS The negative battery terminal is connected to the P-type material. The positive battery terminal to the N-type material The negative potential attracts the holes away from the edge of the junction barrier on the P side. The positive potential attracts the electrons away from the edge of the barrier on the N side. Rectifiers This action increases the barrier width because there are more negative ions on the P side of the junction, and more positive ions on the N side of the junction. This increase in the number of ions prevents current flow across the junction PNP JUNCTIONS FORWARD BIAS a) The collector is connected to high negative voltage with respect to base i.e. Vbc is very high. So c-b junction is reverse biased. The base is connected to low negative voltage with respect to emitter i.e. Veb is low. Also Vbc is always greater than Veb. When Veb is greater than or equal to potential barrier voltage of e-b junction, the transistor is forward biased. Rectifiers Now large number of holes in emitter layer is repelled by positive terminal of Veb and they flow towards e-b junction. They cross the junction and enter into small base layer. Here some electrons combine with holes, some of them are attracted by negative terminal of Veb and remaining large number of holes flow into collector layer, crossing b-c junction. The resident holes of collector are repelled by these (guest) holes and thus, all the holes are attracted by negative terminal of Vbc Rectifiers Thus, all these holes complete their journey back into emitter layer and thus, produce currents in the transistor as shown in the above circuit. Reverse bias a)The collector is connected to high negative voltage with respect to base i.e. Vbc is very high. So b-c junction is reverse biased. The base is connected to low positive voltage with respect to emitter i.e. Vbe is low. Also Vbc is always greater than (–Veb)*. Since battery Vbe is connected in opposite direction, the emitter-base junction is now reverse biased. So the holes in emitter layer are attracted by negative terminal of Vbe and thus, they cannot cross the junction. So there are no holes that can produce base current. Ib = 0. So collector current Ic = 0 and emitter current Ie = 0. Rectifiers

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Rectification 2Nd Module CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Rectification 2Nd Module using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Voltage Rectification RECTIFICATION Self Rectified Circuit Self-rectification Disadvantages Halfwave Rectifier Circuit Halfwave Rectified Circuit Fullwave Rectifier Full-Wave Rectification Pulsed Radiation Three-Phase Generators Ripple Ripple Example Ripple Typical Values Wave Forms of Different Generator Types Filament Transformer Step-up Transformer Autotransformer RECTIFICATION OF HIGH TENSION Voltage Rectification Transformers operate with alternating current. X-ray tubes operate on direct voltage ( electron moving in one direction). To convert AC to DC we use rectifiers. RECTIFICATION changing alternating current into direct current. The device used is called a rectifier. A symbol for rectifier RECTIFICATION … Methods of rectification Self rectification Half wave rectification Full wave rectification Three phase full wave rectification Self Rectified Circuit Secondary of High Voltage Transformer mA waveform The x ray tube is direct connected to secondary winding of the high tension transformer. X-Ray tube acts as rectifier Current only flows from cathode to anode cathode is source of free electrons Rarely seen Voltage applied to tube Self-rectification Disadvantages hot anode can emit electrons accelerate & can destroy filament half of electrical cycle wasted Voltage applied to x-ray tube mA waveform Used Wasted X-Rays Produced Halfwave Rectifier Circuit + X-ray tube connected to secondary of high voltage transformer through diode rectifiers Alternating voltage applied to secondary of high voltage transformer Voltage applied to tube Halfwave Rectifier Circuit + X Second Half Cycle: Diodes open No voltage applied to tube No tube current (mA) + First Half Cycle: Diodes closed Voltage applied to tube Tube current (mA) results – Halfwave Rectified Circuit Secondary of High Voltage Transformer 60 pulses per second only positive half cycle of high tension transformer used inefficient negative half cycle wasted Blocked (not used) Applied to x-ray tube Output of High Tension Transformer Applied to X-ray Tube Fullwave Rectifier Four diodes 120 pulses/second exposure times half of halfwave circuit Secondary of High Voltage Transformer Voltage applied to tube (also mA waveform) Fullwave Rectifier + X First Half Cycle Second Half Cycle Voltage applied to tube (also mA waveform) X + Full-Wave Rectification Rectifiers Four diode “bridge” configuration used with single phase both + & – half cycle of high tension transformer used efficient circuit reverses negative half cycle & applies to x-ray tube Applied to X-ray Tube Output of High Tension Transformer Tube Pulsed Radiation single phase input power results in pulsed radiation Disadvantages inefficiency of radiation production due to the pulsating waveform not providing enough voltage to produce x-rays for a portion of the time. the inability to select short exposure times. Applied to X-ray Tube Radiation Waveform Three-Phase Generators Commercial power generally delivered as 3 phase phases 120o apart Single Phase Power Three Phase Power Three-Phase Generators Rectifier circuit Inverts negative voltage sends highest of 3 phases to x-ray tube To X-Ray Tube Input 3 Phase Voltage Rectified Three-Phase Generators much higher tube ratings than single phase more efficient than single phase shorter exposures lower exposure Three Phase Output Single Phase Power Ripple variation of kilovoltage from maximum usually expressed as percentage of maximum kV Ripple Ripple Example Ripple = 80 – 72 = 8 kVp OR 8 / 80 = .1 = 10% 80 kVp 72 kVp Ripple Typical Values single phase always 100 % (kV ranges from zero to maximum) three phase 4-13% constant potential 0 % Medium / high frequency very low; approx 0. Three Phase Output Single Phase Output Constant Potential or High Frequency Output Wave Forms of Different Generator Types As the ripple effect decreases, the efficiency increases. There is one more type of generator. It uses is called stored energy. The X-ray Circuit Filament Transformer Intended to lower voltage and increase current Allows for thermionic emission to occur at the filament Ultimately, provides the electrons necessary for x-ray production. Tube current measured in mA. Step-up Transformer This transformer is responsible for producing the high voltages necessary for x-ray production. Turns ratio of 500:1 or 1000:1 Autotransformer The autotransformer works on the principle of self-induction. It has a single core and is responsible for varying the voltage. Because of its ability to adjust voltage, the autotransformer can be either a step-up or step-down transformer. ← PREVIOUS TOPICNEXT TOPIC →VIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Radiology Equipment: Operating Principles CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Radiology Equipment: Operating Principles using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic OBJECTIVES Determine care of different radiology and imaging equipment. Understand operation of fluoroscopic machine to examine patient. INTRODUCTION X RAY IMAGING Radiology Equipment: Operating Principles Origin of X-ray Source remains same for all x-ray imaging devices Bone APPLICATION OF X RAY Advantage of x ray imaging ULTRASOUND IMAGING IMAGE FORMATION IN ULTRASOUND APPLICATION OF ULTRASOUND Advantage of ultrasound 2. Non-invasive Approach 3. PAINLESS 4. NO RECOVERY TIME 5. COST SOFT TISSUE DETAILS DIFFERENCE BETWEEN X RAY AND ULTRASOUND FLUOROSCOPY X RAY MACHINE Fluoroscopy Mammography A) Dental (Intra-oral x-ray examination) CT SCAN Bone Mineral Densitometry Equipment RADIOLOGY AND IMAGING EQUIPMENT OBJECTIVES Expected learning outcomes: At the end of the course/module students will be able to: Identify different radiology and imaging modalities. Component of convectional x ray and their functions Describe component and functions of dental equipment Determine care of different radiology and imaging equipment. Identify accessories for radiological investigations To understand operation of x ray machine to examine patients To understand operation of dental x ray machine to examine patient. Understand operation of fluoroscopic machine to examine patient. Understand conducting quality control procedures for x ray machine. Understand conducting of basic quality control procedures for dental x ray machine. To maintain record events of all equipment for maintenance and servicing. INTRODUCTION Medical imaging plays a crucial role in diagnosing and monitoring a wide range of medical conditions. Among the most common imaging techniques are X-ray, ultrasound, CT scan MRI, and radionuclide scan X ray modality can be classified into Dental x ray Mammography Fluoroscopy x ray machine X RAY IMAGING X-ray imaging, uses ionizing radiation to produce detailed images of the body's interior. X-ray Machine: A machine emits a controlled amount of X-ray radiation through the body. Absorption: Dense structures, like bones and tumors, absorb more X-rays, resulting in white areas on the X-ray image. Image Capture: X-rays that pass through the body are captured on a detector, creating an image. Radiology Equipment: Operating Principles Medical imaging of the human body requires some form of energy (radiation). In imaging techniques used in radiology, the energy used to produce the image must be capable of penetrating tissues. In diagnostic X-ray imaging, images are formed by the interaction of the X-ray beam with the patient. As the X-ray beam passes through the patient, the photons interact with the body tissues and are absorbed/scattered by the patient. The degree of absorption is related to the density of the material that is in the beam’s path. Dense objects (such as bone and metal) have a high degree of photon absorption, while less dense objects (such as fat and water) absorbs less photons. The differential absorption of photons by different materials in the photons' path results in the beam exiting the patient with different intensities. This is known as transmitted beam. A detector is used to measure the intensity variation, thus providing information on the different densities in the beam’s path. Origin of X-ray Source remains same for all x-ray imaging devices i.e X-ray tube Evacuated glass tube Target Filament Radiology Equipment: Operating Principles Radiography X-ray equipment has an x-ray tube on one side and an x-ray detector on the other side of the patient. A short duration pulse of x-rays is emitted by the x-ray tube, a large fraction of the x- rays interacts in the patient, some of the x-rays pass through the patient (transmitted x-rays) and reach the detector. These transmitted x-rays form the radiographic image on the film/detector. In radiography, the image is formed with screen-film system, CR cassette or with digital detectors. In screen-film radiography, areas of high intensity (thus low material absorption) within transmitted beam result in more blackening of the film, while areas of low intensity (thus high material absorption) will result in less blackening of the film. The film will remain white in areas with no photons. Human body is made up of tissues with varying densities, in the film black corresponds to tissues with little attenuation (such as air) and white corresponds to tissue with a high degree of attenuation (such as bone). Bone Air Soft tissue X Primary collimation Film, fluorescent screen or image intensifier Beam intensity at detector level « Latent » radiological Image formed Antiscatter Grid Scattered radiation X-ray Image Formation APPLICATION OF X RAY Orthopedics: X-rays are commonly used to detect fractures, bone diseases, and joint problems. Dental: Dental X-rays are essential for diagnosing oral health issues. Chest Imaging: It helps diagnose lung conditions like pneumonia and lung cancer. Mammography: X-ray mammography is used for breast cancer screening. Advantage of x ray imaging noninvasively and painlessly help to diagnose disease and monitor therapy; support medical and surgical treatment planning; and Guide medical personnel as they insert catheters, stents, or other devices inside the body, treat tumors, or remove blood clots or other blockages ULTRASOUND IMAGING Ultrasound imaging, also known as sonography, relies on sound waves to create real-time images of the body's internal structures. IMAGE FORMATION IN ULTRASOUND Sound Waves: A small handheld device called a transducer emits high-frequency sound waves into the body. Reflection: When these sound waves encounter different tissues and organs, they bounce back (reflect) at varying speeds depending on the density of the tissues. Image Formation: The transducer collects the reflected waves and sends them to a computer, which processes the data to create dynamic images on a screen APPLICATION OF ULTRASOUND Obstetrics: Ultrasound is commonly used during pregnancy to monitor fetal development. Abdominal Imaging: It helps diagnose conditions in the liver, gallbladder, pancreas, and other abdominal organs. Cardiac Imaging: Echocardiograms use ultrasound to assess heart function. Musculoskeletal Imaging: It aids in diagnosing soft tissue injuries and joint conditions. Small parts imaging: it helps diagnose conditions of the breast, scrotum, neck and

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Mains Voltage Compensation CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Mains Voltage Compensation using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic MAIN VOLTAGE COMPANSATION Manually adjusted mains voltage compensator Mains Voltage Compensation Automatic adjusted mains voltage compensator LINE DROP COMPENSATOR. MAIN VOLTAGE COMPANSATION Objectives Describe main voltage compensation Explain the factors that lead to main voltage fluctuation Name the components used in main voltage compensation Explain the methods through which main voltage compensation is achieved MAIN VOLTAGE COMPANSATION…… Describe: The manually adjusted mains voltage compensator Automatic mains voltage compensator. Describe the main voltage compensation under the headings: Manual mains voltage compensation Automatic mains voltage compensation MAIN VOLTAGE COMPANSATION…… Describe the effects on the radiograph following the change in compensation devices under the following headings: Tube kilo voltage Tube current The supply of the filament transformer Other components of the x ray set timer, monitors, and relays. MAIN VOLTAGE COMPANSATION The changes that occur in the mains voltage are caused by: Slow changes over a period of time due to differences in demand on the supply at various periods in a day. Rapid changes because some equipment on the line draws a heavy current for short interval. The fall in the main voltage caused by x ray set itself drawing current for radiographic exposure. MAIN VOLTAGE COMPANSATION … The main voltage compensator can not prevent the main voltage changes (above) from taking place. What it can do is to maintain voltage output from the autotransformer of the x ray unit. MAIN VOLTAGE COMPANSATION … This may be manually or automatically adjusted. It acts to maintain a constant volts per turn ration on the autotransformer of the x ray set so that the voltage out put of the autotransformer is not changed by alteration in the input voltage. It compensates for slow voltage changes occurring outside the x ray exposure Manually adjusted mains voltage compensator Consist of tappings on the autotransformer at one end of the winding. The tappings can be on either primary side or on the secondary side. There is also a line voltage compensator meter which is connected across a fixed number of tappings of the autotransformer. It is main function is to indicate any change in the main voltage supply. Mains Voltage Compensation For any change in main voltage supply, the main voltage compensator is manually adjusted by the radiographer whether to increase or decrease the number of turns. ( towards A or towards C) Automatic adjusted mains voltage compensator This type of compensator has an adjustor with special contactor called a sledge which is driven by an electric motor to obtain a constantly balanced output voltage from the autotransformer. LINE DROP COMPENSATOR. This is a special transformer in series with the autotransformer. It functions to provide a voltage to superimpose on the line voltage in such a way that the extra voltage is matched to the fall in the line voltage which occurs when the load current flows against mains resistance. This compensator compensates only for the mains drop caused by the x ray set itself ← PREVIOUS TOPICNEXT TOPIC →VIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Intro To Equipment CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Intro To Equipment using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Intro To Equipment RADIOGRAPHIC & IMAGING EQUIPMENT Equipment What is radiology? Radiology comes from two words Radio- meaning radiation -logos; means ‘science’ or ‘study of’ Radiology is a branch of medicine that uses imaging technology to diagnose and guide treatment of diseases. The main branches of radiology include Diagnostic radiology (diagnose diseases) Interventional radiology (guide treatment) Nuclear medicine; makes use of small amounts of radioactive materials (radiopharmaceuticals) to examine organ function and structure. Radiotherapy Uses controlled doses of radiation to treat diseases, primarily cancer. Doctors that specialize in interpretation of medical images are called radiologists. What is radiography? Radiography comes from two words Radio- meaning radiation Graphy- means ‘to record’ or ‘take a picture’ or ‘create an image’ Therefore; Radiography is the use of high energy radiation to create medical images of inside the human body.What is diagnostic radiography? Diagnosis; is the process of identifying a disease, condition or injury. Diagnostic radiography; is the process of creating medical images of inside the human body for the purpose of identifying a disease, condition or injury. Health care professionals or technologists who deal with creating medical images are called radiographers. What is a radiograph? A radiograph is an image or picture produced on a film or sensitive plate after exposing patient to high energy radiation. A radiograph is the end product of radiography. Medical Imaging Equipment There are several equipment used in medical imaging X-ray machine Dental x-ray machine Ultrasound CT scanner MRI Mammography Fluoroscopy  Gamma Camera PET SPECT Each equipment uses a different technology to create medical images.X-ray Machine An x-ray machine is a medical imaging device that uses xrays to create images of internal structures of the body. X-ray images are useful in assessing the skeletal system (bones) and even some soft tissues especially lungs. X-ray images are two dimensional (2D).Types of X-ray Machines There are three types of x-ray equipment based on their image acquiring systems. Conventional radiography makes use of screen/film imaging system. after exposure, a latent image is created on the film. the film is then processed chemically to produce a manifest image which can be interpreted by a physician. screen and film are placed in a cassette at a very close contact A conventional x-ray machine has the following components; X-ray tube; produces the x-rays X-ray table; used for positioning the patient. Film/Screen; interacts with x-rays to form an image. Control panel; permits the selection of exposure factors (mA, kV and time) and initiation of exposures High-voltage generator; modifies incoming voltage and current to provide x-ray tube with the power needed to produce an x-ray beam of desired peak-kilo-voltage (kVp) and current (mA). Components of high-voltage generator Computed radiography (CR) makes use of cassette based phosphor imaging plates (PSP) to create a digital image. a cassette containing a phosphor imaging plate is exposed then scanned by computerized system (a reader) to obtain a digital image. It is also a form of digital radiography due to production of a digital image. Direct Digital Radiography (DDR) Involves translating x-ray energy into electric signal that is in turn converted into digital data to form a digital image. This is achieved by the use of detectors. A digital x-ray machine has the following components; X-ray tube X-ray table Image receptor Control panel High-voltage generatorX-ray ImagesEquipment Preparation How do I prepare an x-ray machine for an investigation? (i) Wipe the x-ray table, the vertical Bucky and x-ray tube handles with antiseptic solution to avoid cross infection. (iii) Switch on the x-ray generator and the control console. (iv) Warm up the x-ray tube machine at the beginning of the day. (v) Enter patient details ready for exposure.Dental X-ray Machine This is an x-ray machine used by dentists to create medical images of teeth, jaws and other parts of the mouth to diagnose patient’s oral condition. There are two main types of dental x-rays; Intraoral; the film is put inside the mouth. Extraoral; the film is placed outside the mouth. Extraoral X-ray UnitsComponents of Dental X-ray Machine Tubehead; contains the x-ray tube which produces the x-rays. Control panel; permits the selection of exposure factors (mA, kV and time) and initiation of exposures Film; interacts with x-rays to form an image. Support arms; offers mechanical support to the tube head.Dental ImagesUltrasound Machine An ultrasound machine uses high frequency sound waves to create images of inside the body. Ultrasound frequencies in diagnostic radiology range from 2 megahertz (2 MHz) to approximately 15 MHz. The sound humans hear has a frequency range of 20 hertz (20 Hz) to 20,000 Hz.  A healthcare professional or technologist who specializes in ultrasound only is called a sonographer.Ultrasound Images Equipment Preparation How do I prepare an ultrasound machine for an investigation? (i) Make sure an ultrasound probe to be used is connected to its port on the machine. (ii) Connect the ultrasound machine to the source of power if it is not battery charged. NB; It is best to connect the machine to the UPS (Uninterruptible Power Supply) to avoid damage to the machine incase off power outage/cut.(iii) Switch on the ultrasound machine ready for use.CT SCAN The word CT stand for computed tomography. A CT scan uses x-rays to obtain detailed internal images of the body in form of slices/sections. A CT scan also produces 3 dimensional images. Equipment Preparation How do I prepare a CT-scan machine for an investigation? (i) Wipe the CT table with antiseptic solution to avoid cross infection. (ii) Switch on the control console. (iii) Warm up the CT-scan machine at the beginning of the day.MRI MRI stands for magnetic resonance imaging. MRI is a machine which uses magnetic field and radio waves to create detailed images of organs and tissues within the body.MR ImagesMammography Mammography is a radiographic equipment which uses