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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

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 · SEMESTER ONE Dental Equipment CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Dental Equipment using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Learning objectives Dental radiograph: A photographic image produced on film by the passage of x-rays through teeth and related structures. Dental Equipment Why dental radiograph? Root length determination of teeth prior to endodontic therapy. Monitoring the progress of orthodontic treatment and dental disease. X-RAY MACHINE component part (A) control panel, (B) extension arm, and (C) tubehead. Control Panel and circuitry Extension Arm Leaded-Glass Housing Cathode The cathode includes the following: Anode In the production of dental x-rays, three transformers are used to adjust the electrical circuits: Radiographic film Indirect-action or screen film, so-called because it is used in combination with intensifying screens in a cassette. Digital receptors; Electricity and Electrical Currents Rectification is the conversion of AC to DC. The filament circuit uses 3 to 5 V, regulates the flow of electrical current by the milliampere settings. RADIOLOGY AND IMAGING EQUIPMENT Dental x-ray machine Learning objectives Student should be able to describe the components and functions of dental equipment Dental radiograph: A photographic image produced on film by the passage of x-rays through teeth and related structures. Dental radiography: The production of radiographs of the teeth and adjacent structures by the exposure of an image receptor to x-rays. Dental radiographer: Any person who positions, exposes, and processes dental x-ray image receptors. COMPONENT AND FUNCTIONS OF DENTAL EQUIPMENT Dental Equipment Dental imaging is the creation of digital, print, or film representations of anatomic structures of the teeth for the purpose of diagnosis. Dental X-rays (radiographs) are used with low levels of radiation to capture images of the interior of teeth and gums to limit the amount of radiation to patients. Why dental radiograph? Detection of pathology associated with the teeth and their supporting structures such as caries, periodontal disease and periapical pathology. Detection of anomalies/injury associated with the teeth, their supporting structures, the maxilla and the mandible. Determination of the presence/absence of teeth and the localisation of any unerupted teeth. Root length determination of teeth prior to endodontic therapy. Detection of the presence/absence of radio-opaque salivary calculi and foreign bodies. Detection of anomalies/injury/pathology of adjacent facial structures. Evaluation of skeletal and /or soft tissues prior to orthodontic treatment. Monitoring the progress of orthodontic treatment and dental disease. The preoperative assessment of skeletal and soft-tissue patterns prior to orthognathic surgery. Assessment of bone levels prior to implant placement. Monitoring the healing and effectiveness of surgical treatment of the patient postoperatively. Dental Equipment Dental radiography involves techniques in which the image receptor is placed either inside the mouth (intraoral radiography) or outside the mouth (extraoral radiography).Extraoral X-rays show teeth, but their main focus is the jaw and skull. X-RAY MACHINE X-rays are produced in the dental x-ray machine. The dental x-ray machine can be divided into four study areas: (1)The component parts (2) The x-ray tube (3)Image receptors (4) The x-ray generating apparatus. component part This includes conventional dental X-ray units, panoramic X-ray machines, and cone beam computed tomography (CBCT) units. There are several conventional dental x-ray units available from various manufactures. They vary in appearance, complexity and cost,but all consist of three main visible components; (Figure 1) (A) control panel, (B) extension arm, and (C) tubehead. B C A Control Panel and circuitry The control panel of the dental x-ray machine contains an on-off switch and indicator light, an exposure button and control devices (time, kilovoltage, and milliamperage selectors) to regulate the x-ray beam. The control panel is plugged into an electrical outlet and appears as a panel or a cabinet mounted on the wall outside the dental operatory. Extension Arm The wall-mounted extension arm suspends the x-ray tubehead and houses the electrical wires that extend allows for movement and positioning of the tubehead. Tubehead The x-ray tubehead is a tightly sealed, heavy metal housing that contains the x-ray tube that produces dental x-rays. The component parts of the tubehead include the following; Dental Equipment A: Metal housing, or the metal body of the tubehead that surrounds the x-ray tube and transformers and is filled with oil-protects the x-ray tube and grounds the high-voltage components. B:Insulating oil, or the oil that surrounds the x-ray tube and transformers inside the tubehead- prevents overheating by absorbing the heat created by the production of x-rays. Dental Equipment C:Tubehead seal, or the aluminum or leaded-glass covering of the tubehead that permits the exit of x-rays from the tubehead-seals the oil in the tubehead and acts as a Filter to the x-ray beam. (Figure 2) Dental Equipment Also known as the heart of the x-ray generating system it is critical to the production of x-rays and warrants a separate discussion from the rest of the x-ray machine. The x-ray tube is a glass vacuum tube from which all the air has been removed. The x-ray tube used in dentistry measures approximately several inches long by 1 inch in diameter. X-ray tube The component parts of the x-ray tube include a leaded-glass housing, negative cathode, and positive anode (Figure 3). Leaded-Glass Housing The leaded-glass housing is a leaded-glass vacuum tube that prevents x-rays from escaping in all directions. One central area of the leaded-glass tube has a “window” that permits the x-ray beam to exit the tube and directs the x-ray beam toward the aluminum disks, lead collimator, and Position-indicating device (PID).Figure 4 Cathode The cathode, or negative electrode, consists of a tungsten wire filament in a cup-shaped holder made of molybdenum. The purpose of the cathode is to supply the electrons necessary to generate x-rays. In the x-ray tube, the electrons produced in the negative cathode are accelerated toward the positive anode. The cathode includes the following: The tungsten filament, or coiled wire made of tungsten, which produces electrons when heated. The molybdenum cup, which focuses the electrons into a narrow beam and directs

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Component of Conventional X-ray equipment and their function CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Component of Conventional X-ray equipment and their function using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Introduction X-ray machine PARTS OF THE CONVECTIONAL X-RAY MACHINE X -ray tube X ray tube insert Cathode Filament WITHOUT FOCUSING CUP High voltage Anode Anode heel effect Factors affecting anode heel effect Anode angle Target-to-film distance Field size Positioning Stationary and Rotating Anode tubes Rotating vs Stationary anode tube Tube envelope Tube housing Features of x ray tube Housing The oil Collimation Collimators Filters and Filtration Filters Compensation filters METHODS FOR COOLING THE X ray tube cooling methods Tube cooling methods X Ray Tube Support System X ray Tube Stand Features of an Xray tube stand X ray tube Movements Intro. to the x ray circuit Component of convection x-ray equipment and their function Introduction X-ray are ionizing electromagnetic radiation from a highly evacuated hight-voltage tube. Inner orbital electrons in the target anode are stimulated to emit radiation via bombardment by a stream of electrons from heated cathode X-ray , like gamma rays, are penetration and carry enough energy to ionize atoms in their path. X-ray require shielding to reduce their intensity and minimize the danger of tissue damage. It can cause severe radiation burs and deep tissue damage and can lead to various cancers X-ray machine is the type imaging modality that use x-ray to produce a two-dimensional image of the inside of the body A conventional system uses an intensifying screen to create a latent image on x-ray film. The film is then processed, creating a manifest image that can be interpreted by a physician. It is later stored in the file room. PARTS OF THE CONVECTIONAL X-RAY MACHINE X-ray has three main components; Operating console High frequency generator X-ray tube –internal -external Other parts Collimator Patient table Grid bucky X-ray Film X RAY TUBE X -ray tube Within an X -ray tube. Each component part of the X -ray tube has been designed with the desire to produce electrons, supply them with energy and enable an efficient as possible interaction with a target This tube consists of a cathode and an anode enclosed within an evacuated glass or metal envelope This is all contained within lead – shielded housing X-ray tubes X ray tube insert A vacuumed tube which comprises the cathode and anode. Cathode The cathode is the negatively charged electrode, where electrons are released into the X -ray tube by thermionic emission. This is the start of the X -ray production process and consists of two parts: A filament. A focusing cup. The filament is a coil of wire, which is about 2 mm in diameter. It is tightly coiled, similar to the heating element in a bar heater or a toaster, in order to increase the surface area of the metal. Tungsten is a good material for this purpose Filament This means that it can heat and cool quickly, allowing it to be heated rapidly for thermionic emission, and it can withstand high temperatures without becoming damaged. The cathode has its filament circuit that supplies it with necessary filament current to heat it up The rate at which the electrons are emitted by the cathode is directly related to the tube current. WITHOUT FOCUSING CUP WITH FOCUSING CUP High voltage The tube current flows from the cathode to the positively charged anode. A high voltage is supplied across the tube in order to accelerate the electrons and increase their kinetic energy. This voltage is the kilovolt (kV) setting of the tube and is supplied by a source, which is separate from the X -ray tube. Anode The anode is the positively charged electrode, directly opposing the cathode. It consists of a high – density metal target, embedded in a copper disc. The electrons from the cathode hit the target area of the anode and interact. Tungsten is usually chosen as a target material. Anode Tungsten is usually chosen as a target material. This is due to the useful properties of this material. It has a high density, which increases the number of interactions per projectile electron. It also has a high melting point, allowing the target to become very hot without becoming damaged, It has a high thermal conductivity. This means the heat generated in the target is quickly dissipated to the surrounding copper, which acts as a heat sink for the anode. Anode heel effect This is the variation of the intensity of X-rays emitted by the anode along the anode-cathode axis. Occurs due to attenuation of produced beam by the anode. X-rays emitted towards the cathode are in general more intense than those emitted towards the anode. Factors affecting anode heel effect Anode angle Target-to-film distance Field size Positioning Anode angle By increasing the angle, the amount of target material perpendicular to the anode is decreased resulting in less resorption of x-rays produced. Increased anode angle Decreased anode angle Target-to-film distance Increase in distance reduces heel effect by allowing more divergence of the beam which produces a more uniform image. Field size The field will be more uniform at the center (i.e. smaller field size) due to the collimator absorbing the peripheral variations. SMALL field size LARGE field size Positioning By aligning higher attenuating material towards the cathode and lower attenuating material towards the anode the resulting field is more uniform. Stationary and Rotating Anode tubes X ray tube can either has a stationary or rotating anode Most tubes have a rotating anode. This is to increase the efficiency of removing heat from the target area during the production of X – rays, which makes it possible to produce a higher -intensity beam without damaging the area of the anode struck by the projectile electrons. Dental x-ray units, some low-output mobile x-ray machines and mobile fluoroscopy systems

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Room Design CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Room Design using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Introduction Equipment The type of equipment is very important for the following reasons: Usage Surrounding areas Remember we must shield against three sources of radiation Walls Floor Ceiling Control room Doors Labeling and Warning signs Windows X-ray Machine installment General recommendations for the design of a radiology room Room Design Questions Radiography room design Introduction The location, structural design and equipment layout of X‑ray rooms must be carefully considered from a radiation protection perspective. The practical requirements for radiation protection depend on the type of X ray equipment, usage, as well as the workload and adjacent occupancy. Radiography room design ensures radiation safety for patients, staff, visitors, and the public. Equipment What equipment is to be used? General radiography Fluoroscopy (with or without radiography) Dental (oral, cephalometric, or OPG) Mammography CT The type of equipment is very important for the following reasons: where the X Ray beam will be directed the number and type of procedures performed the location of the radiographer (operator) the energy (kVp) of the X Rays Usage Different X Ray equipment have very different usage. For example, a dental unit uses low mAs and low (~70) kVp, and takes relatively few X Rays each week A CT scanner uses high (~130) kVp, high mAs, and takes very many scans each week. Surrounding areas The X Ray room must be designed with knowledge of the location and use of all rooms which adjoin the X Ray room Obviously a toilet will need less shielding than an office Obtain a plan of the X Ray room and surroundings (including level above and below) Remember we must shield against three sources of radiation In decreasing importance, these are: scattered radiation (from the patient) primary radiation (the X Ray beam) leakage radiation (from the X Ray tube) Use a reasonable, worst case scenario (conservatively high estimates), since under-shielding is worse than over-shielding Anything which separates one area from another is called a barrier. Any barrier which may be in the direct X Ray beam is called a primary barrier. If the X Ray beam will never be directed towards a barrier, it is called a secondary barrier. In practice, some barriers will have the primary beam directed at them part of the time only, and the rest of the time they will be a secondary barrier. This must be taken into account in the calculations. Walls The walls shall be constructed using concrete blocks with density of 2.35g/cm3 of at least 30 cm thickness; Lead-Shielding equivalent to atleast 1mm lead Protection needs to extend from the floor to a height of not less than 2m and be continuous. Paint -Smooth (washable paint or easy clean-up) Color –cool color Note ; shielding must be calculated by a physicist or radiation expert Floor Material used is Vinyl floor Vinyl Conductivity-Non-conductive, which is safer around electrical equipment. Absorb rays Fire resistant Slip resistant Shiny Easily cleaned The flooring should be able to bear a load of heavy machines. Shielding equivalent atleast 1mm lead Ceiling Concrete is basic construction material used in floors and ceilings. The radiation attenuation effectiveness of a concrete barrier depends on its thickness, density and composition. using an average density concrete of 2.35gcm-3, a thickness of atleast 150mm and 100mm is ideal for ceiling and for floor respectively. The minimum ceiling height should be 2.5m. Control room There should be a control cubicle/room constructed by using concrete blocks 30 cm thick with a wall height of at least 2.4 m from the floor to the ceiling; The cubicle should have a patient viewing window of a size of at least 60 cm x 70 cm. The viewing window should be installed with a radiation shielding glass (lead glass) preferably of 2.7 mmPb/150 kV thickness or 2.1mmPb/110kV. The lower margin of the window should be at 120 cm from the floor; The control room has to be of adequate size to accommodate computers, image reader(s), printer(s) and personnel. Doors All doors leading to examination room should be shielded with at least 2 mm of lead sheet or 4 mm iron sheet and overlap of atleast 10 cm each side of the door The door(s) leading to the X-ray room are shielded to ensure that radiation leakage through the shutters and frames of the door(s) do not exceed 0.5 μSv/hr; All door should have handles and locks on the inside and the outside so that they may always be closed during exposures thus controlling access. Labeling and Warning signs The public and workers should be aware of the presence of radiation in any room. Therefore, standard radiation warning signs and notices at all entrances with a standard radiation sign must be displayed. The labelling or notices shall be in English and any other language. The redlight showing x-ray machine is in use must be installed at the top of each door leading to the x-ray room. Windows The windows are avoided to reduce the penetration of radiation in the surrounding area. Windows are not preferred in the x-ray room, but if there are installed they must be atleast 2.4m above the floor from the outside and access must be prevented Air conditioning machine is advised for cooling purposes of the X-ray machine. X-ray Machine installment The x-ray machines must be installed in the corner so that there is enough moving space Any x-ray equipment must be installed adequately shielded rooms to ensure that workers and the public in the vicinity oof the x-ray installation are not unduly exposed to x-ray radiation. Exposure button; remain atleast 6 feet( 2 meters) away from an x-ray radiation source. General recommendations for the design of a radiology room The equipment should be positioned so that the primary radiation beam is not directed at

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Accessories for Radiological Investigations CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Accessories for Radiological Investigations using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Learning Objective: Imaging Accessories: Grids, filters, contrast media injectors. Grids: Improve image contrast by reducing scatter radiation. Radiolucent Tables: Ensure minimal interference with imaging. Sandbags Personal Protective Equipment (PPE): Lead aprons, gloves, thyroid collars. PACS: Streamlines storage and retrieval of imaging data Grids: Verify correct placement to reduce scatter radiation Transducer Selection: Choose based on the targeted anatomy (e.g., vascular, abdominal) Inspect all accessories for wear and tear. Enhance Imaging Quality: Categorizing and organizing accessories is essential for optimizing radiological practices. Accessories for Radiological Investigation Learning Objective: At the end of this session student must be able to: Identify accessories for radiological investigation. Organize different accessories for different radiological examination. Perform accessories preparations for different radiological investigation. Introduction Imaging Accessories: Grids, filters, contrast media injectors. Patient Positioning Devices: Radiolucent tables, immobilizers, supports (Foam wedges, sandbags, and straps). Safety Equipment: Lead aprons, shields, radiation dose monitors. Software Tools: PACS, image processing software. Categories of Radiological Accessories Grids: Improve image contrast by reducing scatter radiation. Filters: Enhance clarity for specific imaging needs. Contrast Media Injectors: Precise delivery with features like automatic flow rate control. Imaging Accessories Radiolucent Tables: Ensure minimal interference with imaging. Immobilizers: Provide stability for precise imaging. Adjustable Cushions: Enhance patient comfort and positioning. Patient Positioning Devices Sandbags foam wedge Head rest Patient Positioning devices strap Personal Protective Equipment (PPE): Lead aprons, gloves, thyroid collars. Radiation Shields: Mobile and fixed barriers. Radiation Dose Monitors: Real-time feedback for exposure optimization. Safety Equipment Lead shields How to wear lead aprons and collar shield PACS: Streamlines storage and retrieval of imaging data Advanced Image Processing Tools: AI-enhanced clarity, 3D reconstructions Software Tools Grids: Verify correct placement to reduce scatter radiation Lead Shields and Aprons: Inspect for defects, ensure availability Positioning Aids: Set up foam wedges, straps, and sandbags as needed Film Holders/Markers: Organize for proper identification and positioning Preparing Accessories for Radiological Investigations Transducer Selection: Choose based on the targeted anatomy (e.g., vascular, abdominal) Gel Warmers: Prepare and ensure availability for patient comfort. Sterile Covers: Ready for procedures requiring sterility (e.g., biopsies). Patient Positioning: Arrange pillows or supports for optimal imaging angles. Preparation for Ultrasound Imaging Inspect all accessories for wear and tear. Confirm functionality of electronic devices (e.g., injectors, monitors). Organize and label accessories for easy identification. Ensure compliance with safety and hygiene standards. Checklist for Accessory Preparation Enhance Imaging Quality: Reduce noise and artifacts Optimize diagnostic accuracy Improve Safety: Minimize radiation exposure Ensure patient comfort Increase Operational Efficiency: Faster workflow Reduce equipment downtime(Extended lifespan of accessories and equipment) Importance of Accessories in Radiology Categorizing and organizing accessories is essential for optimizing radiological practices. Ensure the right accessory is available for each specific examination. Promote a culture of efficiency, safety, and quality in radiology. Proper preparation of accessories is vital for successful radiological investigations. Conclusion Any Question ???.. ← 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 Electrical Gadgets and Plugs CRT04104 · Radiology and Imaging Equipment START READING NOTES Study Electrical Gadgets and Plugs using the sections below. Use the topic navigation to continue through Radiology and Imaging Equipment. Contents of This Topic Electrical Gadgets and Plugs Plugs and Power Connections: These are the physical connectors and wiring that supply power to the gadgets. Key Safety Measures: 1. Inspect Power Cords and Plugs: 3. Check Power Indicators: Additional Steps: Technicians: Conduct daily checks and basic functionality testing. Electrical Gadgets and Plugs Electrical Gadgets and Plugs Electrical Gadgets: These include all essential powered devices in the radiology suite that are essential for imaging and diagnostic procedures. Examples include: Imaging Machines, Computers and Monitors, Control Panels. Definitions Plugs and Power Connections: These are the physical connectors and wiring that supply power to the gadgets. They ensure that devices have a stable power source, essential for consistent and accurate operation. Definition cont… Electrical Gadgets and Plugs Radiology relies on high-powered machines and precision electronics thus faulty connections or devices can lead to inaccurate diagnostics, safety risks, or equipment downtime. Impact on Patient Safety: Protects patients from potential electrical hazards and Ensures equipment operates at optimal capacity. NB: In radiology, maintaining these electrical gadgets and their plugs is crucial to prevent equipment malfunction, ensure patient safety, and uphold accurate diagnostic standards. Importance of Electrical Safety in Radiology Key Safety Measures: Always turn off equipment before checking plugs or connections. Use insulated gloves if handling potentially faulty cables or plugs. Maintain dry conditions to reduce electrical hazards. Ensure all high-voltage areas are clearly marked. Safety Precautions 1. Inspect Power Cords and Plugs: Look for signs of wear, fraying, or damage. Confirm plugs fit securely in sockets without excessive force. Test Functionality: Power on the device to check basic functions. Ensure no unusual sounds or lights indicating faults. Step-by-Step SOP – Daily Checks 3. Check Power Indicators: Ensure all indicator lights display normal operating status. Document Findings: Record any issues in the maintenance log. Report major issues to the biomedical engineering team immediately. Daily checks cont…. Additional Steps: Perform a deeper inspection with specialized tools if necessary. Check internal components (if authorized and trained). Test connections with a multimeter or circuit tester. Monthly Detailed Inspections Technicians: Conduct daily checks and basic functionality testing. Biomedical Engineering: Handles detailed inspections, repairs, and replacement of faulty components. Supervisors: Ensure SOPs are followed and documented correctly. Roles and Responsibilities ← 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