10502015
Description
Flashcards by Rebecca Jones, updated more than 1 year ago
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Created by Rebecca Jones
about 7 years ago
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| Question | Answer |
| What is the filament of the cathode made of and why? | Thoriated Tungsten - because it provides for higher thermionic emission than other metals |
| Why is the focusing cup of the cathode negatively charged? | So that it electrostatic ally confines the electron beam to a small area of the anode |
| What 3 functions does the anode perfume in an x-ray tube? | 1. It is an electrical conductor 2. It provides mechanical support for the target 3. It acts as a good thermal radiator |
| Why is the disc or a rotating anode made of tungsten alloyed with rhenium, as opposed to being made solely of tungsten? | Because it gives the disc added mechanical strength to withstand the stresses of high-speed rotation |
| What are the 2 principal components of an induction motor? | Stator windings Rotor |
| Define 'image matrix' and 'pixel' | Image matrix - a layout of cells in rows and columns Pixel - each separate cell of an image matrix is a picture element/pixel |
| State the function of an image intensifier tube | It converts the pattern of the x-ray beam into a bright, visible light image |
| What is the envelope of the X-ray tube made of? | Glass or metal |
| What is the target of a stationary anode made of? | Tungsten alloy metal |
| If you were to alter the target angle, what else would you be altering? | The size of the effective focal spot |
| Define fluorescence | Light emission starts when the exciting radiation starts and stops when the exciting radiation stops |
| What two effects comprise luminescence? | Phosphorescence Luminescence |
| Define quantum mottle | is defined as the variation in density of a uniformly exposed radiograph that results from the random spatial distribution of the x-ray quanta absorbed in the screen. It is obvious when quantity (amount) of x-ray photon are less/low mAs |
| Define radiographic noise | Produced by the random interaction of x-rays with an intensifying screen. This effect is more noticeable when very high kVp is used |
| Define the term 'latent image' | the image produced on the film after exposure but prior to development |
| Name two advantages to automatic processing over manual processing | Time - more films processed per hour Lower water consumption Reduce film wastage Space saving |
| What does DICOM stand for and what is it? | Digital Imaging and Communication in Medicine It is the standard for image transmission |
| Are CR plates more sensitive to scatter radiation than film/screen combinations? | yes |
| What is the structure of a CR imaging plate? | Protective layer Phosphor layer Light reflection layer Conductive layer Support Light shielding layer Backing layer / barcode label |
| What are 3 advantages to CR and PACS? | rapid image access rapid film filing and retrieval Post processing image manipulation Reduction of storage space required Ability to view the same image at 2 different sites simultaneously |
| Electrons are released during the exposure, where are they held and for how long are the held there? | Excited electrons are trapped in the F centres They can be held there for days |
| What happens to the electron when the laser strikes the phosphor? | They are released from the traps and emit light |
| What are 5 pieces of accessory equipment you might find in any x-ray room? | Chairs, grids, pen and paper, sandbags, NOPs, weights, steps, sellotape, pillows, filters |
| What is the purpose of a grid? | to reduce the amount of scatter radiation that reaches the IR in order to improve image contrast |
| Define 'grid ratio' | The height of the strips divided by the width of the interspace material Grid ratio = h/d |
| Define grid frequency | The number of grid lines per cm |
| What are 4 types of grids? | parallel focused moving cross hatched |
| Name the material used for the grid lines | lead |
| Name the material used for the interspace in a grid | Aluminium Carbon fibre Plastic fibre |
| Name 1 major disadvantage that accompanies the use of a grid | increased patient dose |
| What advantage do moving grids have over stationary grids? | the grid lines are blurred out |
| Name 3 main methods of x-ray tube support | Ceiling support system Floor to ceiling support system C arm support system |
| What is the function of the protective housing of the x-ray tube? | To guard against excessive radiation exposure and electrical shock To provide mechanical support for the tube and protect the tube from damage due to rough handling |
| What are the two primary parts to the cathode? | filament focusing cup |
| Is the cathode the positive or negative side of the x-ray tube? | negative |
| Name five parts that make up an x-ray tube | Protective housing, envelope, cathode, anode, filament, induction motor, focussing cup, target, anode stem, bearings |
| What are the 3 methods by which the x-ray tube / anode cools? | Convection Conduction Radiation |
| Why is the filament considered to be a thermionic device? | Cause it emits electrons when it is heated |
| For what 3 reasons is tungsten the material of choice for the target? | High atomic number Thermal conductivity nearly equal to copper High melting point |
| What 2 things does a rotating anode permit? | Higher tube currents Shorter exposure times |
| What is the target? | the area of the anode struck by the electron from the cathode |
| What are age 3 main sections of the x-ray imaging system? | x-ray tube operating console high voltage generator |
| Name 2 pieces of accessory equipment you should find in the mobile machines | lead lead gowns exposure chart NOP cushioned cassette holder |
| What are the 3 basic radiation protection principles? | Justification (of the practice) Optimisation (of protection) Limitation (of individual dose risk) |
| What is justification? | No practice shall be adopted unless its introduction produces a positive net benefit to the exposed individual or to society |
| What is optimisation? | In relation to a particular practice, the magnitude of individual doses, the number of people exposed and the likelihood of incurring exposure shall be kept as low as reasonably achievable, economic and social factors being taken in account |
| What is limitation? | The risks either from a dose or a potential dose to a class of individuals shall not exceed the limits set for that class |
| What is the effective dose limit for radiation personnel? | An effective dose of 20mSv per year averaged over any 5 year period and 50mSv in any one year |
| What are the equivalent dose limits for radiation personnel? | 500 mSv to the skin in any 1 year 150mSv to the lens of either eye in any 1 year 500mSv to the hands and feet in any 1 year |
| What is the dose limit for women who declare themselves pregnant? | 1mSv at the surface of the abdomen for the remainder of the pregnancy |
| What are the equivalent dose limits for non-radiation personnel? | 50 mSv to the skin in any 1 year 15mSv to the lens of either eye in any 1 year 50mSv to the hands and feet in any 1 year |
| What is the effective dose limit for non-radiation personnel? | An effective dose of 1mSv in any one year |
| Describe radiation personnel | people who are employed are an x-ray facility whose work directly and centrally involves the use of x-rays |
| Describe non-radiation personnel | people who are employed at an x-ray facility but whose work does not directly and centrally involve the use of x-rays e.g: reception staff, nurses |
| Describe an equivalent dose | is the absorbed dose averaged over that tissue or organ and weighted for the radiation quality of interest |
| Describe an effective dose | is the weighted equivalent dose in all the tissues and organs in the body |
| You are x-raying a little kid who won't stay still and the mother is pregnant. Who do you get to hold the child? | Not an MRT, reception staff, nurse or orderly or another family member if present |
| If you are on mobiles, do you really need to wear a lead gown or could you just rely on the distance principle? | Yes you do need to wear a gown, both CSP5 and Wellington Hospital protocols state to do so |
| For persons performing general radiography, where should their radiation badge be worn? | On their trunk between chest and waist level |
| What are 3 ways to minimise the need for repeats as stated by CSP5? | ensuring all radiation personnel are appropriately qualified Ensuring all equipment complies with the code of safe practice Ensuring all equipment and facilities are part of a QA programme |
| What are 5 ways of minimising patient dose as stated by CSP 5? | Collimate beam tightly Use additional filtration where possible Use highest kVp possible Fastest film/screen combo Longest FFD practicable Antiscatter grids only when necessary Gonad shielding where practicable Number of views in exam kept low Film processors monitored in QA prog Observe pt during exposure |
| Why is stricter justification of paediatric x-rays important? | Longer life expectancy so greater potential for manifestation of harmful effects of radiation Less co-operative, breathe faster increasing chance of repeats |
| Your paediatric pelvis pt comes into the room with 6 siblings and a mother at her wits end. She will only get your pt undressed to their nappy & ribbed singlet. What will you tell her to persuade her to remove the nappy? | CSP5 states that as clothing and nappies may produce artefacts on the film, especially with young children, all clothing should be removed from the body part to be examined |
| If your attempts of strapping a screaming child to the bed are not successful, what other method can you try and why is it worthwhile? | Try to establish rapport with patient. This is important because although it is time consuming it decreases radiation dose and produces a successful examination |
| What 3 features shall an LBD have? Briefly describe each one. | Accuracy – alignment of light field with x-ray field Delineation – cross-hairs indicating centre of x-ray beam Illumination – brightness of the light beam |
| What 2 things can you say about warning lights on the x-ray control panel? | Shall be a light on the control panel that is illuminated when machine is ‘on’ Shall be a light illuminated in prep mode Shall be a light illuminated in exposure mode |
| How thick should a primary barrier be? | Shall have a lead equivalence of 2.0 mm |
| How thick should a secondary barrier be? | Should have a lead equivalence of 1.0 mm |
| Without relying on your e.s.p, what is one way of knowing that: A) a room is used for x-raying patients & B) x-rays are in process? | A) Sign on door of room B) Light above the door outside the room that is illuminated in prep and exposure mode |
| If you were put in charge of making exposure charts for the new x-ray room in your dept, what would you use as a guide to ensure patients were not being over-exposed? | Annex 2 of CSP5 sets out quality criteria for the highest dose examination |
| What do individual dose limits represent? | The boundary between unacceptable doses and doses that are tolerable |
| How much lead shielding should be placed over a pregnant women’s abdo if her foot is being x-rayed? | Apron or similar with a lead equivalence of not less than 0.5 mm |
| What is the permissible focus-skin distance as set by NRL? | Focus-skin distance shall not be less than 400 mm and should not be less than 500 mm |
| What is the minimum permissible FFD for chests and other body part imaging according to CSP5? | Chest radiography – FFD should not be less than 150 cm Remaining x-ray procedures – FFD should not be less than 100 cm |
| If a 17 yr old mum comes in with her 3 month old baby who is having a CXR, can the mother hold her baby if she is definitely not pregnant? | No – no young persons under the age of 18 yrs shall do any holding of patients |
| What are 2 of the 4 early effects of radiation on humans? | Acute radiation syndrome Local tissue damage Hematologic depression Cytogenic damage |
| What are 2 of the 5 late effects of radiation on humans? | Leukaemia Other malignant diseases Shortening of the lifespan Local tissue damage Genetic damage |
| What are 3 of the 5 effects of foetal irradiation? | Prenatal death Neonatal death Congenital malformation Childhood malignancy Diminished growth and development |
| What molecule in the human body is primarily radiosensitive? | DNA |
| What are 3 ways of identifying your patient? | DOB Address Full Name Another family member Nurse/Doctor Bradma on hospital bracelet |
| Explain the 3 cardinal rules with regard to radiation protection? | Time – time of exposure to radiation should be as short as possible Distance – maintain a large distance between source of radiation and exposed person (Inverse square law) Shielding – Should be shielding where possible between source and exposed person |
| What trimester is considered to be the most radio-sensitive? Why? | The first trimester because it is the time when organogenesis is occurring |
| Would you say that a tape measure on the machine that lets you measure the FFD could be considered as a tool of radiation protection? | Yes |
| In NZ, who monitors the occupational radiation doses of radiation personnel? | National Radiation Laboratory (NRL) in Christchurch |
| Why is it important that film badges are worn the right way round? | Because radiation that enters the back of the badge indicates higher exposures since the x-rays would have penetrated through the body before interacting with the film badge |
| What metal are the filters found inside a film badge generally made of? | Aluminium and Copper |
| Describe a stochastic effect. | Effects occur at random and are unrelated to a specific radiation dose. No threshold limit exists. Chance of developing a stochastic effect increases with increasing number of exposures |
| Describe a non-stochastic/deterministic effect. | Effects that can be related to a specific radiation dose. A threshold limit exists, below which the effect will not occur |
| Give an example of a stochastic and non-stochastic effect. | Stochastic – Leukaemia Non-Stochastic – Erythematic, Sterility, Cataracts, Life shortening, congenital malformations |
| What should the total filtration of the incident primary x-ray beam be? | Shall not be less than 2.5 mm Aluminium |
| Explain your obligations with respect to informed consent. | Explain the procedure/examination Explain possible risks involved/side effects Should be done in a non-threatening environment |
| True/False: the use of a compensatory filter reduces the dose to the patient? | True |
| Does increasing the kVp increase or decrease the skin dose to the patient? | Decreases the skin dose to the patient because the beam will have more penetrating ability and so will be able to pass through the body and not be absorbed by the skin |
| What function related to CR has the ability to decrease the patient dose? | The post-process function |
| What ‘bad habit’ is important to monitor with CR as it may increase the dose to the patients? | Exposure Creep |
| Bones can be classified into what 4 categories? | Long Short Flat Irregular |
| Give 2 examples of a short bone and 2 examples of a long bone? | Short – Carpal bones, Tarsal bones Long – Humerus, Femur |
| How much movement would you expect from a synarthrodial (fibrous)joint? | eg. skull suture, syndesmosis, gomphosis None – it’s an immovable joint. |
| How much movement would you expect from an amphiarthrodial (cartilaginous) joint? | eg. pubic symphsis, interveteral disc Very little – the joint has limited movement. |
| How much movement would you expect from a diarthrodial (synovial) joint? | eg. ball&socek ,hinge bursa and tendon sheaths Lots – a freely moveable joint. |
| Define ‘arthrology’ | The study of joints or articulations |
| What level does the vertebra prominens landmark correspond with? | C7/T1 |
| What landmark could be used to locate the stomach, gallbladder or upper abdo? | Xiphoid process of sternum |
| What level does the inferior costal margin landmark correspond with? | Stomach, Gallbladder, ribs |
| What is the difference between hyposthenic, hypersthenic and sthenic body habitus? | Sthenic - average Hypersthenic – short and wide Hyposthenic – tall and thin |
| Radiographic anatomy of the chest is divided up into which 3 sections? | Bony thorax Respiratory system proper Mediastinum |
| Draw or describe the pathway that air travels from the trachea into each lung. | Trachea – carina – Lt and Rt primary bronchus – secondary bronchus – bronchioles – terminal bronchioles – alveoli. |
| Food and FB’s are more likely to get stuck in which primary bronchus and why? | The right because it is more vertical, shorter and wider than the left |
| How many lobes in the left and right lungs? | Left – 2 lobes Right – 3 lobes |
| What 4 radiographically important structures are located within the mediastinum? | Thymus gland Heart and great vessels Trachea Esophagus |
| What are the 4 types of pneumonia? | Aspiration Broncho(staphylococcus bacteria) Lobar(confine 1 or 2 lobes) Interstitial (viral inflammation of alvoli) |
| What is a pneumothroax? | An accumulation of air in the pleural space resulting in partial or complete collapse of that lung and SOB and chest pain |
| What does RDS stand for and what is it? | Respiratory Distress Syndrome Alveoli and capillaries of the lung are injured or infected resulting in leakage of fluid and blood between/within alveoli result in collapse of the alveoli - density throughout lung in a granular patten “air-bronchogram” |
| Name 3 occupational lung diseases and comment on each. | Silicosis – caused by inhaling silicon dust Anthracosis – caused by inhaling deposits of coal dust Asbestosis – caused by inhaling asbestos dust |
| What are 3 possible types of pleural effusion? | fluid Empyema – pus Chylothroax – milky fluid(lymph) Haemothroax – blood |
| What is a pleural effusion? | A condition of abnormal accumulation of fluid in the pleural cavity 400 mL of fluid must be present before a pleural effusion will be seen on plain films |
| What is pneumonia? | An inflammation of the lungs resulting in accumulation of fluid within certain sections of the lungs |
| What is chronic Obstructive pulmonary disease COPD and what other abbreviations can be used to describe it? | A from of persistent obstruction of airway as caused by emphysema or bronchitis. Smoking is the main cause. COAD, CORD, COPD, CORD |
| List 5 pathologies that might be seen on a CXR. LVF failure Pneumothorax Pleural effusion Dextra Cardia Pneumonia Pulmonary oedema Atelectesis Pleurisy Bronchitis Emphysema COPD TB | LVF failure, Pneumothorax, Pleural effusion, Dextra Cardia, Pneumonia, Pulmonary oedema, Atelectesis, Pleurisy, Bronchitis, Emphysema, COPD, TB |
| What is haemoptysis? | Coughing up blood |
| What are the 3 parts that constitute the small bowel? | Duodenum Jejunum Ileum |
| Draw the large bowel to show: | Caecum Ascending colon Hepatic Flexure Transverse colon Splenic Flexure Descending colon Sigmoid colon |
| Name 3 accessory organs of digestion located in the abdomen. | Pancreas Liver Gall bladder |
| What structures make up the urinary system? | Bladder Ureters x2 Urethra Kidneys x2 |
| What are the 4 quadrants of the abdomen? | RUQ RLQ LLQ LUQ |
| What is ascites? | Abnormal accumulation of fluid in the peritoneal cavity. |
| What is a pneumoperitoneum? | Refers to gas or air within the peritoneal cavity |
| What is intersussception? | The telescoping of a section of the bowel into another loop |
| What is a volvulus? | The twisting of a loop of intestine, creating an obstruction |
| Name the carpal bones? | Scaphoid Lunate Triquetral Pisiform Hamate Capitate Trapezoid Trapezium |
| What are the 4 indicators of OA? | Subchondral cysts Decreased joint spaces Osteophytic lipping Sclerotic (hardening) margins |
| Name the tarsal bones? | Navicular Talus Cuboid 1st cuneiform 2nd cuneiform 3rd cuneiform Calcaneus |
| True/False: the fibular is a weight-bearing bone? | False |
| Name the type of osteochondritis that is related to an avulsion # of the tibial tuberosity? | Osgood Schlatters |
| Name the 3 parts to the pelvis. | Ilium Ischium Pubis |
| List the 3 differences between a female and male pelvis. | Male – narrow and deep general shape Acute angle of pubic arch Heart shaped pelvic inlet Female – shallow & wide general shape Obtuse angle of pubic arch Round shaped pelvic inlet |
| What 2 pathologies does shenton’s line help to diagnose? | # DDH SUFE |
| What does SUFE stand for? | Slipped upper femoral epiphysis |
| What are the 3 parts to the vertebral column? | Cervical Thoracic Lumbar |
| What is lordosis? | The increased swayback curvature of the spine |
| Draw the 9 abdomen quadrants | R. & L. hypochondriac R. & L. lumbar R. & L. inguinal Epigastric Hypogastric Pubic |
| What is kyphosis? | Abnormal or exaggerated thoracic humpback curvature with increased convexity |
| What is scoliosis? | Abnormal or exaggerated lateral curvature |
| What is spondylitis? | Inflammation of the vertebrae |
| What is ankylosing spondylitis? | Systemic illness involving the spine and larger joints. Results in pain and stiffness as a result of inflammation, calcification and ossification of the spinal joints. AKA bamboo spine. |
| Describe spondylolisthesis. | Forward slipping of one vertebrae over another due to defect of pars interarticularis. Usually at L5/S1 junction. |
| What is spina bifida? | A congenital condition in which the posterior arches of the vertebrae fail to develop, exposing part of the spinal cord. |
| What is osteomyelitis? | A localised infection of bone/bone marrow. The infection may be caused by bacteria from a penetrating trauma, post-op surgery or # complications. |
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