Positioning Unit 4-5: Upper Extremity + Shoulder

patient prep

patient prep

remove rings, watches, bracelets that will be in field of view; document when a patient is unable/unwilling to remove items

when positioning a patient, what should you NEVER do?

force movement; ask a patient what they are able to do, encourage them

where should the CR be for extremities?

joint space (varies depending on exam)

what should collimation include?

the desired anatomy, and the anatomy immediately proximal and distal

casts and their mAs adjustments

fiberglass cast— no adjustment

dry plaster— 2x mAs (or more)

wet plaster— 3-5x mAs (or more)

PA hand recipe

• hand flat on IR, fingers separated

• include ~1” of distal radius and ulna

• CR at 3rd MCP joint

• 55-60 kVp, 1.2-2.0 mAs

oblique hand recipe

• 45° rotation of entire hand, fingers straight

• CR at 3rd MCP joint

• 3, 4, 5 MC shafts close, but do not overlap

• 55-60 kVp, 1.2-2.0 mAs

lateral hand recipe

• hand, wrist, and distal radius + ulna should all be completely lateral

• proximal MCs superimposed

• fingers spread; “fan”

• CR at 2nd MCP joint

• 55-60 kVp, 1.2-2.0 mAs

finger recipe

• same positioning as hand, and same views

• FOV to include finger of interest and distal MC

• CR at PIP joint of desired finger

• 55-60 kVp, 1.2-2.0 mAs

• the less OID the better, so keep desired finger as close to the IR as possible

thumb recipe

• AP (preferred)/PA, oblique (PA hand = oblique thumb), lateral

• CR at 1st MCP joint

• 55-60 kVp, 1.2-2.0 mAs

• FOV to include trapezium

what size focal spot should be used on a finger?

small focal spot

ball catchers recipe

• both hands in AP oblique position, fingers extended but relaxed

• 60 kVp, 2.0 mAs

• to evaluate for rheumatoid arthritis

PA wrist recipe

• curl fingers under to form loose fist so wrist is flat against IR

• CR at mid-carpals (center of wrist)

• FOV should include distal forearm, all carpals, and some of MCs

• 60 kVp, 1.5-2.0 mAs

oblique wrist recipe

same as PA wrist, but rotate to 45° angle

lateral wrist recipe

• elbow bent and level with wrist

• radius and ulna superimpose

• 60 kVp, 2.0 mAs

• CR at center of wrist

  • FOV from mid-MCs to distal forearm

radial deviation

hand deviates toward the radius, which opens up the medial wrist joint

ulnar devation

hand deviates toward ulna, which opens up lateral wrist joint for a “scaphoid view”

PA scaphoid recipe

ulnar deviation with CR perpendicular to wrist

PA axial scaphoid recipe

ulnar deviation with 15° CR angle proximally (toward elbow)

modified Stecher recipe

• ulnar deviation with hand elevated 20°

• CR perpendicular to scaphoid

• 60 kVp, 2.0 mAs

  • in cases of severe pain, perform view without ulnar deviation (everything else stays the same)

carpal tunnel (Gaynor-Hart) recipe

• CR 1” above base of 3rd MC with a 25-30° tube angle (in line with long axis of hand)

• tangential view (skims surface of anatomy)

• if patient is unable to keep hand vertical, give them a towel/pillowcase to hold in position

• 60 kVp, 2.0 mAs

AP forearm recipe

• arm fully extended, with shoulder, elbow, hand all in same plane

• elbow AP, supinate hand

• FOV: from just above crease of elbow and past wrist

• CR at center of forearm

• 60-65 kVp, 2.0-3.2 mAs

lateral forearm recipe

• shoulder, elbow, hand all in same plane

• lateral elbow bent at 90°, wrist lateral with distal radius and ulna superimposed

• CR at center of forearm

• 60-65 kVp, 2.0-3.2 mAs

AP elbow recipe

• arm fully extended (shoulder, elbow, hand all in same plane)

• CR at humeroulnar joint space (elbow crease)

• there should be partial (1/3-½) overlap of radius and ulna, and the humerus should be end-to-end with radius

• 65-70 kVp, 2.5-4.0 mAs

external oblique (laterally rotated) elbow recipe

• humerus at 45° external rotation so capitulum is profile

• there should be NO overlap of radius and ulna

• CR at humeroulnar joint space

• 65-70 kVp, 2.5-4.0 mAs

internal oblique (medially rotated) elbow recipe

• pronate palm so humerus is at 45° internal rotation and trochlea & coronoid process are in profile

• FOV to include mid-humerus to mid-radius/ulna

• CR at humeroulnar joint space

• 65-70 kVp, 2.5-4.0 mAs

lateral elbow recipe

• shoulder, elbow, hand all in same plan

• elbow at 90°, wrist lateral

• humeral condyles should be superimposed

• CR at humeroulnar joint space

• 65-70 kVp, 2.5-4.0 mAs

• FOV to include proximal radius & ulna, and distal humerus

lateral elbow image analysis criteria

shoulder-elbow: distal borders of capitulum and trochlea within trochlear notch; about half (±) of radius over coronoid process

elbow-wrist: anterior borders of capitulum and trochlea within trochlear notch; head of radius aligned with inner coronoid process

Coyle view

an alternate internal and external oblique view for trauma patients, or for when a patient is unable to extend elbow; CR angled to move radius relative to ulna

external Coyle recipe

• CR 45° toward shoulder (tube in front of patient), aligned at humeroulnar joint

• 90° flexion of elbow (with elbow, shoulder, hand all in same plane) to project radius free of ulna

• 65-70 kVp, 2.5-4.0 mAs

internal Coyle recipe

• CR 45° away from shoulder (tube behind patient), aligned at humeroulnar joint

• 90° flexion of elbow (with elbow, shoulder, hand all in same plane) to project radius fully onto ulna

• 65-70 kVp, 2.5-4.0 mAs

partial flexion elbow

for when a patient is unable to fully extend elbow to get true AP, instead perform an AP proximal forearm + AP distal humerus

AP humerus recipe

• 70-80 kVp, 4-12 mAs

• CR at center of humerus

• AP elbow with epicondyles parallel to IR, and externally rotated shoulder

• FOV to include glenohumeral joint (humerus in shoulder socket), elbow joint, and proximal radius & ulna

lateral humerus recipe

• 70-80 kVp, 4-12 mAs

• CR at center of humerus

• elbow lateral with epicondyles perpendicular to IR and internally rotated shoulder (more than one way to achieve this position, do whatever is most comfortable for patient)

• FOV to include glenohumeral joint, elbow joint, and proximal radius & ulna

fracture (fx)

a break in bone or cartilage; can be traumatic or pathologic

fat pad sign

negative: anterior fat pad is visible flat against distal humerus, but posterior fat pad is not visible

positive: anterior fat pad is elevated away from distal humerus, and posterior fat pad is visible; caused by joint effusion and is evidence there is likely a radial head/neck fx (even if it isn’t visible)

bursitis

inflammation and swelling of bursa due to accumulation of fluid

dislocation (luxation)

an abnormal separation in the joint

subluxation

partial dislocation

osteoarthritis

degeneration of the joint cartilage resulting in bone rubbing against bone, and bone and joint erosion and deformation

osteopenia

loss of bone mass (precedes osteoporosis)

osteoporosis

significant loss of bone mass; bones become radiolucent on films (subtractive pathology, ½x mAs)

which demographic is osteoporosis more commonly found in?

post-menopausal women

osteopetrosis (“marble bone”)

bone is more dense than normal due to abnormal volume of bone growth; bones appear bright, “glowing” white on radiographs (additive pathology, 2-3x mAs)

AP neutral shoulder recipe

• patient is AP with shoulder “as is”

• CR 1” inferior to coracoid process

• perform in cases of suspected trauma when patient is unable to rotate humerus

• 70-85 kVp, 6-20+ mAs

AP internal shoulder recipe

• patient AP with shoulder internally rotated (have patient place back of hand against thigh)

• CR 1” interior to coracoid process

• humerus should be lateral, glenoid should be oblique, which causes overlap of humeral head and glenoid

• 70-85 kVp, 6-20+ mAs

AP external shoulder recipe

• patient AP with shoulder externally rotated (have patient supinate palm)

• humerus should be AP, glenoid should be oblique, which causes overlap of humeral head and glenoid

• 70-85 kVp, 6-20+ mAs

Grashey/Posterior oblique recipe

• patient rotated 35-45 degrees toward afflicted side, which puts the glenoid into profile

• should NOT be overlap of glenoid and humeral head so glenohumeral space can be clearly seen

• humerus should be:

  • neutral per textbook, ARRT

  • external rotation in dept

• 70-85 kVp, 6-20+ mAs

inferosuperior axillary shoulder recipe

• patient is supine with cassette above shoulder with arm abducted 90 degrees externally (helps hold cassette also)

• CR 25-30 degrees to axilla/humeral head

• 70-80 kVp, 6-16 mAs

superoinferior axillary shoulder recipe

• patient sitting with cassette under armpit, arm abducted 90 degrees externally

• CR 25-30 degrees to axilla/humeral head

• 70-80 kVp, 6-16 mAs

scapular Y (PA/anterior oblique) shoulder recipe

• patient angled 45-60 degrees toward side of interest in order to get scapular body perpendicular to IR

• medial margin aligned with acromion/humeral head

• 75-85 kVp, 10-40 mAs

scapular Y (AP/posterior oblique) shoulder recipe

• patient angled 45-60 degrees toward side of interest in order to get scapular body perpendicular to IR

• acromion/humeral head aligned with lateral margin

• 75-85 kVp, 10-40 mAs

outlet/Neers view recipe

• done PA with scapula lateral

  • same patient positioning as lateral/scapular Y view

• CR 10-15 degrees caudad

• demonstrates the coracoacromial arch

• should look like a scapular Y with humeral head lower to see through the outlet

• 75-85 kVp, 10-40 mAs

AP scapula recipe

• abduct humerus 90 degrees and supinate hand (rest on top of head if more comfortable for patient) to move lateral portion of scapula away from ribs

• elbow against IR to get scapula flat

• CR midscapula

• 70-85 kVp, 10-25 mAs

lateral scapula recipe

• same view as scapular Y for shoulder exam but humerus must NOT be over body of scapula

AP clavicle recipe

• 0 degree tube angle with CR at jugular notch

• FOV collimated down around borders of clavicle

• 70-85 kVp, 6-40 mAs

AP axial clavicle recipe

• CR 15-30 degrees cephalad

• medial end of clavicle projected up to 1st rib, but most of clavicle is free of ribs

• expose at the end of full inspiration

• 70-85 kVp, 6-40 mAs

PA axial clavicle recipe

• patient PA

• CR 15-30 degrees caudad

• decreases OID (increases detail and decreases magnification)

• 70-85 kVp, 6-40 mAs

AC joint recipe

• standing at 72” SID

• CR level with AC, centered at jugular notch

• each exam has two images: one with weights, one without weights (MUST label which is which)

• include both AC joints on each image

• if patient is very broad-shouldered, do PA instead of AP

• done to look for AC joint separation

• 70-85 kVp, 6-40 mAs

transthoracic lateral shoulder recipe

• this view is done when patient is unable to move arm (neutral)

• affected side is closest to IR

• CR perpendicular to level of affected surgical neck

• 70-85 kVp, 20+ mAs with free breathing (4-5 second exposure preferred)

dislocated shoulder

humeral head is not sitting in glenoid fossa

which views help determine whether a shoulder dislocation is anterior or posterior?

Y-view, axillary

acromioclavicular separation

tearing of the ligaments of the AC joint, causing the bones to separate

osteoarthritis

degeneration of the joint cartilage resulting in bone rubbing on bone, and bone and joint erosion and deformation