Presentation on theme: "Mobile Radiography (Portables)"— Presentation transcript:
1 Mobile Radiography (Portables) 8/29/2012 Class ed.
2 Principles of Mobile Radiography You bring imaging services to pt using transportable x-ray equipmentWhere are they commonly used?pt roomERICUsurgery and recovery roomsnursery and neonatal unitsWhen was mobile x-ray equipment first used?battlefield WW1 -units were carried to field sites
3 Mobile X-Ray MachinesTrue or false? Portables are as sophisticated as stationary units?FalseTypical unit has what 2 controls?kVp and mAsWhat is the mAs range?Generally 0.04 to 320 mAsWhat is the kVp range?-generally 40 to 130 kVp
4 Two basic types of Mobile X-Ray Machines 1. Battery poweredUses two different sets of batteries (lead-acid, or nickel-cadmium )One powers driving of machineOne set provides power to x-ray tubeFully charged batteries:- can make 10 to 15 exposures- be driven reasonable distances2. Capacitor discharge (obsolete)No batteriesCarries two metal plates that hold electrical chargeCapacitor units must be charged prior to each use
5 Battery-operated Unit Advantages:CordlessProvide constant kVp and mAsDisadvantages:- Heavy- hard to controlWhat is “Deadman” type of brake?stops machine instantly when push-handle released
6 Capacitor Discharge Units Advantages?lightweight, smaller and easier to maneuverrequire much less time to charge than battery unitsDisadvantages?can’t handle thick body parts due to voltage drop during exposuremust be charged prior to each use
7 The Nomad For places with no electricity or chemical processors Mainly for dental x-rays
8 3 important technical factors that must be clearly understood to perform optimum mobile examinations:GridAnode-heel effectSource–to–image receptor (SID)
9 Grid Must be level! X-ray beam must be properly centered to grid Correct focal distance must be used(Best grids for mobile radiography have ratios of 6:1 or 8:1 and a focal range of inches)Make sure grid is fastened to cassette properly (tape)
10 Anode Heel EffectCorrectly place anode-cathode (marked on tube housing) with respect to anatomyAnode should be on thinner part (T-spine)Heel effect increases with short SID, larger field sizes (more common in mobile radiography)Beam travels through thicker part of target on anode side, thus attenuating beam more
11 SID- Mobile Units What is standard SID? 40 Possible problems with greater SID?Need increased mAs, thus longer exposure timeIncreases risk of imaging motionIncreased drain on batteryPossible grid cut-off
12 Performing Mobile Examinations Plan ahead!Gather all necessary devices to take with youIR (bring extras!)GridTapeMarkersSponges
13 Before Beginning Examination Find pt’s x-ray orderLet nurse’s station know of your presence and purposeIdentify pt and introduce yourself with your titleExplain exam and ensure it is appropriate and correctPolitely ask any visitors to leaveObtain assistance when necessary!
14 Interfering DevicesWatch out for orthopedic beds, fracture frames, tubes, wiring, etc., producing artifactsKnow which objects can be moved and which ones you have to work aroundMay have to perform with object in imageAsk if unsure whether an object can be moved
15 Portable PositionIf exam in supine position, move base of machine to middle of bedIf seated upright, base at end of bedLateral and decubitus positions, place base parallel or perpendicular to bed
16 Performing Mobile Examinations Make sure collimation is not open larger than IR sizeCheck CR and IR alignment to prevent distortionUse consistent system for keeping exposed and unexposed IRs separateKeep log of procedures, time of examination, technical factors for image ID
17 Technique Charts and Logs Exposure for optimum exam!Should be available for every machineShould display standard technical factors for all projections performed with machineLogbook of all recent pt exams and techniqueCaliper should also be available for accurate patient measurement
19 Wear film badge at collar or waist outside lead protection Mobile radiography produces some of highest occupational radiation exposure for radiographers!Wear a lead apron!Wear film badge at collar or waist outside lead protectionWhat is single most effective radiation protection measure?Distance!What is minimal safe distance ?6 feet
20 Safest Place to StandLeast exposure is at what angle to pt and primary beam?Right angle
21 When should you shield pt’s gonads? X-raying childrenPerson is of reproductive agePt requestsGonads lie in or near useful beamWhen shield will not interfere with anatomy of interest
22 Radiation Safety cont’d What is minimum source-to-skin distance?12Have visitors leave areaWarn other personnel when you are about to make an exposure
23 Patient Mobility Never move pt or part without: Assessing ability to move or ability to tolerate movementChecking with staff obtain assistance and permission to move a part that has had surgery or fracturedInappropriate movement can further injure pt!
24 Warn pt of potential discomfort from IR ColdHardIR can damage skin of older patientUse cloth or paper cover to reduce risk of injuryProtect IR from contamination by use of appropriate impermeable cover
25 Assess Patient Condition Be aware of any limitations to procedure!AlertnessRespirationAbility to cooperateLanguage comprehensionMobilityFracturesInterfering devicesIf in OR, don’t break sterile field!
26 Isolation Considerations What are two types of pts in isolation?Those who have contagious infectious microorganismsyou want to avoid them!Those who must be protected from exposure to infectious microorganisms-they want to avoid you!This known as?Reverse isolation!
27 Isolation Considerations cont’d Wear all required protective apparel for specific situationWash hands before glovingProtect IR with protective cover
28 Isolation Considerations cont’d After procedure:Discard of protective apparel according to protocolWash hands!Wear clean gloves to clean equipment and use appropriate aseptic techniqueWash hands again after removing gloves
29 Most Common Portable Radiographic Exams ChestAbdomenPelvisFemurCervical spineNeonate
30 AP Chest Elevate head of the bed as pt condition permits Pull pt to head of bed before elevating if condition permitsMake sure pt is not rotatedWhat if pt has respiration assistance?watch pt chest to determine inspiratory phase (or respirator)
31 AP or PA Chest Lateral Decubitus Position Place firm support under pt to elevate body and keep pt from sinking down in bedProtect pt from rolling off of bed!
32 Lateral Decubitus Position Considerations Fluid levels best imaged with?affected side downAir levels seen best with?affected side upHow long should pts be in this position before exposure?5 minutesWhy?to allow fluid or air to settle
33 Orthopedic Examinations How many images required?at least 2 films at right angles to each otherWho do you obtain permission from prior to moving an injured pt?pt’s nurse or physicianHow do you position pts?very carefully!
34 Lateral Cervical Spine Dorsal decubitus positionCR horizontalIf there is a immobilization device when should you remove it?NEVER or until Dr. gives permission
35 Neonate Move arms out of anatomy of interest Bring legs down Who should hold infant in position?Nurse- (provide lead apron)Why do you leave head rotated?to avoid advancing endotracheal tube too farCollimate closelyShield gonads
36 NeonateAP projection of chest and abdomen often ordered and shot in one exposureInfant is supineSome bassinets equipped with tray to hold IRIf IR placed directly under infant- wrap with soft cover
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