Chapter 15: Trauma, Mobile, and Surgical Radiography
C-arm Orientation and Exposure Patterns
30 deg. c-arm tilt - increased exposure to face and neck by a factor of FOUR
Dislocation
Displacement of bone from the joint, no longer in contact with its normal articulation - movement painful and must be avoided - imaged in 2 planes: -- Shoulder dislocation -- Other common: fingers, patella, hip
Boxers fx
Distal 5th metacarpal, seen on lateral, punching
Anatomic apposition
End to end contact
Lack of apposition
Ends to aligned but separated
Trauma principle 2
Entire structure or trauma area on IR - initial long bone studies require that BOTH joints be demonstrated for each projection - follow-up studies usually require ONLY the joint nearest the injury
Mallet or baseball fx
Injury is caused by forcibly flexing the DIP joint during active extension. Striking the fingertip when attempting to catch a ball
Contusion
A "bruise" type injury without a fracture or break in the skin
lateral humerus
CR parallel to epicondyles
AP shoulder
CR perpendicular to shoulder joint
Varus angulation
Toward midline, apex angulation lateral
Butterfly
two oblique fracture lines meeting to create a large triangular or wedge-shaped fragment located between the proximal and distal fracture fragments, and resembles a butterfly wing
non sterile field
where the technologist as well as other non sterile surgical personnel such as the anesthesiologist and the circulation is located
external fixation
fracture-stabilizing device permits bone healing without the immediate requirement for internal fixation - severe open fractures, comminuted closed fractures, arthrodesis, infected joints, and major alignment and length deficits - ilizarov device: correct length deficit - pelvic external fixator
Depressed fx
ping-pong fx. fx of skull where a fragment is depressed
Smiths fx
(reverse colles) fx anterior displacement
Complete fractures
- (Two pieces) - transverse fracture - oblique fracture - spiral fracture
Trauma adaptation positioning: principle 1
- 2 projections 90 deg. from each other - often with no patient movement -adapt CR angles and IR placement to minimize further injury or discomfort to the patient
Trauma AP skull
- AP: 0 deg., CR parallel to OML, CR to glabella - AP "reverse caldwell" : CR 15 deg cephalic to OML, CR to nasion
AP and and lateral knee
- AP: no CR angle for average patient - Lateral: Horizontal CR parallel to epicondyles
Lumbar laminectomy/fusion
- C-arm set up for AP projection (patient prone) - C-arm alignment for lateral projection
HIp pinning procedures
- C-arm setup with fx table - Shower curtain separates sterile from non sterile areas - C-arm alignment for lateral hip (recommended c-arm position, intensifier near surgeon) - C-arm alignment with X-ray tube near surgeon (not recommended)
Trauma AP axial projection
- CR 30 deg caudal to OML - CR to level of EAMs
Modified AP waters
- CR parallel to LML - CR enters acanthion - Petrous ridges in mid aspect of maxillary sinuses - best demonstrates floor of orbits and entire orbital rims
AP reverse waters
- CR parallel to MML - CR enters acanthion - Petrous ridges just below maxillary sinuses
Trauma lateral skull
- CR: 2 inches superior to EAM - No tilt or rotation - No suspected C-spine injury - w/o head manipulation
AP supine abdomen
- CR: at iliac crest
Lateral Scpaular Y
- CR: cross angled if required - grid crosswise
AP humerus
- CR: perpendicular to epicondyles - Include both joints
Alternative imaging modalities
- CT: fast, accurate, 3D capabilities - Ultrasound: blunt injury, free air/fluid, pregnancy/ectopic - Nuclear medicine: PE, blood flow - Angiography and interventional procedures: AO arch, embolize hemorrhage
Trimalleolar fx
- Common in accidents where a huge force is applied on the ankle, like skiing sports or an automobile accident - common in aging populations, who are active - Osteoporosis also increase the risk
Incomplete fracture
- Fracture does not transverse through entire bone - Examples: Torus, greenstick, plastic
Transthoracic lateral proximal humerus
- Horizontal CR to surgical neck and centerline of grid - Raise unaffected arm above head, elevating the unaffected shoulder
Trauma axiolateral projections of elbow
- Projection for radial head- CR: angled 45 deg. toward shoulder - Projection for coronoid process- CR: angled 45 deg. away from shoulder
Stellate fracture
- This # occurs in the flat bones of the skull and patella - Fracture lines run in various directions from one point - Star like
Principle 1 exceptions
- barriers to true AP and lateral (splints, traction bars, etc.) - Exceptions to true CR-part-IR alignment
Hutchinson fx
- chauffeur's fx -radial styloid process (hand cranked cars)
General types of fractures
- complete - comminuted - impacted
Horizontal beam projections
- divergency of xray beam - ensure that body part is not projected off IR
Evaluation criteria: OC
- entire biliary ducts filled and demonstrated - no motion - optimal exposure factors
Stress or fatigue fx
- non-trauma - overuse or repetitive activity injury - occurs when muscles become fatigued and are unable to absorb added shock - eventually, fatigued muscle transfers the overload of stress to the bone causing a tiny crack - marching: Midshaft of metatarsals (or knee) - running: distal shaft of tibia possibly hip
Radiation protection with C-arm
- place X-ray tube under table to reduce head and neck exposure to operator - minimize use of boost exposure - minimize distance between anatomy and image intensifier - provide lead aprons for those remaining inure not behind lead shields
Scrub
- prepares and maintains sterile surgical field and instruments - gowns members of surgical team
Surgical Attire Technologist
- scrubs - shoe covers - non sterile gloves - protective apron - head cover - surgical mask
Left lateral decubitus
- support board or sufficient pads - CR 1-2 in. above iliac crest - NO R. lateral - arms above head - Allows determination of air- fluid levels and possible free intra-abdominal air
Lateral decubitus chest
- to determine air-fluid levels - radiolucent pads under shoulders and hips - arms above head - CR: 3-4 in. below jugular notch, level of T7
Mobile and trauma radiography
- trauma patient on stretcher - mobile (portable) chest procedure
Dorsal decubitus (lateral) projection
- useful projection to rule out possible abdominal aortic aneurysm - CR: iliac crest
Protecting the sterile environment: 3 methods
1. draping c-arm 2. draping patient 3. shower curtain
3 cardinal principles of radiation
1. distance 2. time 3. shielding
Types of proximal femur fractures
1. femoral neck 2. comminuted subtrochanteric 3. intertrochanteric
Surgical team
1. surgeon 2. Certified surgical tech (CST) 3. Radiologic technologist 4. Scrub (CST or RN)
Fracture
A break in the bone
Splintered
A comminuted fracture characterized by shattered fragments of sharp bone
Potts fracture
Ankle fracture of distal fibula with frequent fracture of medial malleolus. Major injury and ligament tears - common term for bimalleolar fx
Bennetts fx
Base of 1st metacarpal, CMC jt
mobile (portable) xray equipment: Type 1
Battery powered, battery driven - 10-16 rechargeable 12V batteries - speed 2.5 to 3 mph (maximum incline 7 deg.) - recharged with 110V or 120V source - 8 hours to charge if fully discharged
Avulsion fractures
Bone attached to tendon or ligament pulls the piece of bone away
Lateral Elbow
CR: parallel to interepicondylar plane
PA elbow
CR: perpendicular to interepicondylar plane
Operative Cholangiogram
Conventional mobile x-ray unit positioned for AP projection - centering point indicated by surgeon
Apposition
Describes how the fragmented ends of the bone make contact with each other - types: Anatomic, Lack of apposition, bayonet
Colles fx
Distal radius, posterior displacement, usually forward fall
internal fixation
During open education fractures, a variety of compression plates, screws, pins, intramedullary rods, nails, or wires applied to reduce or realign the fracture - these devices are left in place and the skin is closed around the device
Sprain
Forced wrenching or twisting of a joint, resulting in partial rupture or tearing of supporting ligaments
Bayonet apposition
Fragments overlap, shafts make contact, not ends
C-arm Orientation and Exposure Patterns
Horizontal - Increased exposure at xray tube end
Angulation
Loss of alignment
Trauma principle 3
Maintain the safety of the patient, health care workers, and the public - all equipment returned to original position (or better!) - never exposure with unshielded person in vicinity of primary beam - ALARA applies to everyone
mobile (portable) xray equipment: Type 3
Mobile C-arm Fluoro - induces: -- c-arm with xray tube and image intensifier -- TV monitors (2) - features: -- digtal imaging and storage -- image hold feature -- image enhancement, masking, and subtraction
Impacted fracture
One fragment driven into another (ends of bones)
Subluxation
Partial dislocation of joint - C-spine (C5 vertebra displaced posteriorly) - Nursemaids elbow: an example of partial dislocation of radial head (kids)
mobile (portable) xray equipment: Type 2
Standard power - source (110 or 220 V) - capacitor discharge (not common) - much lighter, usually not motor driven - stores electrical charge for greater electrical power upon making exposure
Segmental fracture
The bone is broken in two places, which leaves at least one bone segment floating and unattached
Comminuted fractures
Two or more fragments - segmental - butterfly - splintered
Compression fracture
Vertebral body collapses or is crushed
C-arm Orientation and Exposure Patterns
Vertical AP orientation (left) - should be avoided, increased exposure to head and neck
C-arm Orientation and Exposure Patterns
Vertical PA (right) - least exposure to operator
Valgus angulation
away from midline, apex angulation medial
Simple fracture
bone does not break through skin (closed fracture)
Compound fracture
bone protrudes through skin
Attributes of the Surgical Technologist
confidence, mastery, problem-solving skills, communication
Retrograde urography
conventional cystic table and x-ray unit - nonfunctional examination of the urinary system during which contrast medium is introduced directly retrograde (backward, against the flow) into pelvicalyceal system via catheterization - performed to determine the location of undetected calculi or other types if obstruction in urinary system
Apex angulation
describes the direction or angle of the apex of the fracture - Varus - Valgus
Baseball fx
distal phalanx, ball hitting fingers
Bartons fx
distal radius
Pathologic fx
fracture due to bone disease process - osteoporosis - bone cancer
intramedullary fixation
intermedullary rods and nails are inserted within the shaft of long bones to stabilize fractures - this technique is popular for reducing shaft fractures of the humerus, tibia and femur
Hip fractures and pinning
internal fixation of fractured hip with cannulated screws (for nondisplaced femoral neck fractures)
Chip fx
like avulsion but no tendon involvement
Sterile field
patient, surgical field, surgeon and surgical assistants, surgical equipment, tables and carts
Hangman fx
pedicles of C2
Monteggia fracture
proximal ulna along with dislocation of radial head, from defensive move of raising forearm
Weak, ill and injured patients
requires adaption in positioning and care - mobile - immobilized-backboard, splints, collars - often done supine - stationary grids
Surgical asepsis
separation between sterile and non sterile areas