Introduction to MRSC1150 Diagnostic Radiography Methods 1 2024 PDF

Introduction to MRSC1150 Diagnostic Radiography Methods 1 2024 Peter Stanwell – [email protected] MRSC1150 Assessments In-class invigilated quizzes undertaken during tutorial: Week 3- 20% Week 5- 20% Week 12- 20% Final Examination in formal examination period: 04 Nov. – 15 Nov....

Introduction to MRSC1150 Diagnostic Radiography Methods 1 2024 Peter Stanwell – [email protected] MRSC1150 Assessments In-class invigilated quizzes undertaken during tutorial: Week 3- 20% Week 5- 20% Week 12- 20% Final Examination in formal examination period: 04 Nov. – 15 Nov. 2 Today we will cover 1. Overview of Imaging Modalities 2. General Radiography 3. Imaging fundamentals: Technical Parameters Exposure Density and Contrast Radiation Protection 3 As your training progresses… Aim to learn more about the profession and the role of a radiographer There are many different job descriptions within radiography There are many different modalities used in imaging Once graduated you could all have different career pathways 4 What does a Radiographer do? Produce high quality medical images Uses ionising radiation safely Work in a team of health practitioners in a range of settings 5 What does a Radiographer do? 6 Imaging includes (and for Registration you need to be aware of) General Radiography Computed Tomography (CT) Fluoroscopy Magnetic Resonance Imaging (MRI) Angiography Mammography Ultrasound 7 For program completion and Registration, you need to demonstrate capabilities in: General Radiography Computed Tomography (CT) Fluoroscopy Magnetic Resonance Imaging (MRI) Angiography Mammography Ultrasound 8 General Radiography General Radiography As a student and graduate radiographer, majority of your training will focus on general radiography Plain radiographs will be ordered for various presentations and often look to answer a specific clinical question There are a series of standard and modified projections for each different anatomical region of the body Radiographic technique must account for a wide range of patients of different sizes, ages and mobility levels A list of the series (and projections) most radiographers know can be found below. You will learn majority of these views throughout the program https://radiopaedia.org/articles/general-radiography-curriculum 10 September 3, 20XX 11 Radiography: General Process 12 Radiography depends on density differences  Each anatomical area will have a normal appearance (what is regarded as within normal limits for the patient presentation) Departmental protocols are designed to provide required information using the minimum number of projections These projections complement each other to allow evaluation of the area Each projection (radiograph produced) needs to be evaluated alone and as a part of the protocol (all projections) to determine its value to the examination (Critiquing) Hand X-ray Series Technical Parameters These are the elements of the examination that we use as radiographers to acquire the image. There will be different parameters for each body region, This includes: Positioning of patient and tube- FFD (focus to film distance), tube angle Exposure (kVp and mAs) Collimation Centring Exposure Determined as appropriate by the radiographer Will change when imaging smaller or larger than the average (adult) patient Paediatric patients will receive lower exposure Kilovoltage Peak (kVp) kVp: “Penetration power” Increase kVp: kVp a tube voltage factor that ↑ beam energy radiographers manipulate on the x-ray console ↑ penetration kVp controls acceleration of electrons from ↑ scattering Cathode to Anode ↑ image density It determines the power and strength of the penetration through a body part It determines the quality of the x-ray beam ↓ image contrast 22 Milliampere-Seconds (mAs) mAs: “Number of x-rays” mAs is a factor that radiographers manipulate Increase mAs: on the x-ray console mA controls production of electrons and ↑ in mA will lead to more photons reaching the ↑ ↑ image density detector ↑ number of photons s is a measure of the electrons production ↑ number of interactions duration in the tube; meaning 's' prescribes how long mA will last ↑ patient absorbed dose mAs affects film contrast. If there are not enough x-rays reaching the film mAs = mA x time e.g. 200mA x 0.1sec = 20mAs 23 Tissue Density on Radiographs When a radiographic image is created- this is essentially a ‘map’ of x- rays that have: Passed freely through the body Have been absorbed/scattered by anatomical structures The denser the tissue, the more x-rays are absorbed. And the ‘Whiter” (radiolucent) or more ‘Radiopaque’ the area will be 24 Tissue Density on Radiographs Radiolucent Radiolucent refers to materials or structures that allow the passage of X-rays through them, resulting in a dark or black image on a radiograph. Radiolucent structures have lower density and absorb less radiation compared to radiopaque structures. 25 Tissue Density on Radiographs Radiopaque Radiopaque materials are those that appear white or lighter on an X-ray image. These materials absorb or block X-rays and do not allow them to pass through. Radiopaque materials are typically denser and have a higher atomic number than surrounding tissues, making them more visible on X-ray images. 26 Tissue Density on Radiographs 27 Tissue Density on Radiographs 28 Tissue Density on Radiographs High Density Tissue: Bone absorbs more radiation High density structure “Whiter appearance” Low Density Tissue: Lungs are filled with air Air is a low-density anatomical structure “Darker appearance” 29 High Density Tissue (bone) Low Density Tissue (lung) 30 Describing tissue densities 31 32 33 Why are densities important? We need to see the different densities of anatomical tissues to be able to observe abnormalities These abnormalities could be: Air in an area it shouldn’t be Fluid in an area it shouldn’t be Soft tissue lesions Anything that differs from normal anatomical structures 34 Why are densities important? 35 Radiographic Contrast: The difference in densities between structures that are next to each other 36 High Radiographic Contrast Few densities and greater difference among them More “black and white” 37 Low Radiographic Contrast Many grey tones and less difference between individual densities More “shades of grey” 38 Radiographic Contrast 39 Radiographic Contrast HIGH CONTRAST LOW CONTRAST (low kVp exposure) (high kVp exposure) 40 Why is radiographic contrast important? High contrast (low kVp)= abrupt density differences. Subtle details can be missed or not imaged. Low contrast (high kVp)= more scatter will exit the patient and add unwanted density or fog For each anatomic region there will be an accepted range of kVp that is used to provide the right amount of radiographic contrast. 41 Why is radiographic contrast important? Osteolytic 42 Radiation Protection 43 Radiation Protection ALARA Principle The standard by which all Radiographers must uphold themselves to in our code of conduct. The exposure set should be as low as possible to achieve a diagnostic image for reporting. A = As L = Low A = As R = Reasonably A = Achievable 44 ALARA is achieved by: For the Radiographer: Time = ↓ time spent near radiation source Distance = ↑ distance from radiation source Shielding = lead gown on the radiographer or stand behind the console 45 ALARA is achieved by: For the Patient: Minimal number of projections Appropriate exposure parameters Accurate collimation Immobilisation to reduce possible movement Pregnancy check Gonad shielding- sometimes 46 Radiographer Role Understanding what projections are needed Deciding how to do it Explaining to patient and altering technique if needed Radiation safety Critique of imaging Adapting/adding to protocol if required Self-improvement 47 X-Ray Laboratory Rules You must all remember that you are working with radiation, and this has the potential to do harm if used incorrectly. The x-ray labs on campus are real x-ray units so please always apply the ALARA principle. Always check that the door to the x-ray room is closed, and nobody remains in the room before exposure If there are ever any error messages or you are unsure seek help from your lab supervisor 48 X-Ray Laboratory Rules 1. For the first x-ray that you take in the lab your lab supervisor must check the exposure before you expose. This will be the case in the first few weeks. 2. Make sure you check the door is closed and nobody remains in the room before exposing. If in doubt do not expose and CHECK the room 3. Each member of the group is responsible for each other- if anything dangerous occurs all will be held accountable 4. Report dropped digital detectors or any other equipment faults immediately to your lab supervisor- the machine keeps a log of when it has been dropped so it is better to own up to it 49 X-Ray Laboratory Rules Rules must be followed in the labs as equipment that you are using needs to be used in a manner that will be safe clinically These are simulation labs but are fully operational This will prepare you for when patients, their carers, other health care providers are introduced into the setting while on placement It is the radiographer’s responsibility to ensure radiation safety 50 Any questions? 51