positioning wrist & forearm

why do a AP wrist? (non-routine)

- Advantage: Better view of carpal interspaces as compared to PA projection as carpals are aligned more parallel with divergent beam Disadvantage: May be more difficult for patient to get into that position

medial oblique structures shown

- Best demonstration of lateral sided carpal bones (esp. scaphoid and trapezium) -Medial sided carpals superimposed -Distal radius and ulna and proximal up to half of MC's (at minimum) -Soft tissue & bony trabeculae

PA wrist structures shown

- Frontal view of carpal bones (some slightly superimposed) -Distal radius and ulna up to mid Metacarpals -Wrist joint & radioulnar joints -Soft tissue & bony trabeculae

lateral wrist patient position/part

- Patient seated 90 degrees from table with upper extremity on same plane -Instruct patient to flex elbow at 90 degrees with medial/ulnar side of wrist against the IR (latero-medial lateral) -Adjust wrist so it is truly lateral by palpating distal radius & ulna to ensure they are superimposed (don't let it fall anterior)

medial oblique wrist patient part/postion

- Patient seated 90 degrees from table with upper extremity on same plane -Pronate hand and instruct patient to extend fingers -Laterally rotate wrist 45 degrees from IR until it is semi-pronated (use wedge if needed for support)

why angle the beam 20 degrees

- can be performed with no beam angulation, but this will produce a foreshortened image of the scaphoid -It is preferable to produce a scaphoid image that is either en face (visualizing it's face). -Reason for using beam angulation is clear when you consider the anatomic orientation of the scaphoid in the wrist

lateral oblique wrist structures shown

-Best demonstration of medial carpal bones (pisiform "pops out" and is in profile) -Lateral sided carpals superimposed -Distal radius and ulna up to half of MC's minimum -Soft tissue & bony trabeculae

lateral forearm eval criteria

-Distal radial and ulna superimposed with radial tuberosity facing anteriorly -Elbow flexed 90 degrees and humeral epicondyles superimposed

lateral wrist eval criteria

-Distal radius & ulna truly superimposed (looks like single bone) -Extent of collimation depends on department protocol

AP forearm structures shown

-Frontal view of forearm to include elbow and wrist joints (proximal row of carpals) -Soft tissue and bony trabeculae -Image generally displayed as "hanging from fingers" but heed to dept. protocol

lateral forearm structures shown

-Lateral view of forearm to include elbow and wrist joints (proximal row of carpals minimum) -Soft tissue and bony trabeculae -Image generally displayed as "hanging from fingers" but heed to dept. protocol

lateral wrist structures shown

-Lateral view of superimposed carpals, proximal in MC's, distal radius and ulna -1st metacarpal separated -Soft tissue & bony trabeculae

AP forearm position patient/part

-Patient seated 90 degrees from table with upper extremity on same plane -Adjust forearm into a true AP by palpating humeral epicondyles to ensure they are parallel to plane of IR -Supinate hand and instruct patient to extend fingers using sandbag on palm if needed -IR must be at least 1 ½ -2 inches beyond both wrist and elbow joints to ensure they are included in image (due to divergence of beam)

PA wrist position of patient and part

-Patient seated 90 degrees from table with upper extremity on same plane -Center the wrist joint to center of IR -Pronate hand and instruct patient to flex ("cup") fingers to reduce object to image distance and get carpals a little closer to IR

lateral forearm patient position/part

-Patient seated 90 degrees from table with upper extremity on same plane -Instruct patient to flex elbow at 90 degrees with medial/ulnar side of wrist/forearm against the IR (latero-medial lateral) -Adjust forearm so it is truly lateral by palpating distal radius & ulna to ensure they are superimposed -Ensure humeral epicondyles are perpendicular to IR -IR must be at least 1 ½ -2 inches beyond both wrist and elbow joints to ensure they are included in image (due to divergence of beam

PA axial scaphoid patient position and part (stetcher method)

-Patient seated 90 degrees from table with upper extremity on same plane -Pronate hand with fingers extended -Instruct patient to ulnar deviate wrist to isolate the scaphoid from adjacent carpals

lateral oblique wrist position of patient/part (not routine at CCMC)

-Patient seated 90 degrees from table with upper extremity on same plane -Supinate hand and instruct patient to extend fingers -Medially rotate wrist 45 degrees from IR until it is semi-supinated

lateral forearm CR direction/location

-Perpendicular to enter mid shaft of forearm -Align CR with IR -Collimate side to side only

AP forearm CR direction/position

-Perpendicular to enter mid shaft of forearm -Align CR with IR -Collimate side to side only to include both wrist and elbow joints, and include marker

PA wrist CR direction and location

-Perpendicular to enter mid-carpals -Align CR with midpoint of IR -Collimate side to side; include distal radius/ulna in light field, as well as marker (check dept.protocol)

lateral oblique wrist CR direction/location

-Perpendicular to enter mid-carpals -Align CR with midpoint of IR -Collimate side to side; include distal radius/ulna in light field, as well as marker (check dept.protocol)

medial oblique wrist CR direction and location

-Perpendicular to enter mid-carpals -Align CR with midpoint of IR -Collimate side to side; include distal radius/ulna in light field, as well as marker (check dept.protocol)

lateral wrist CR direction/location

-Perpendicular to enter mid-carpals on lateral side (increase 4-6KVP) -Align CR with midpoint of IR -Collimate side to side; include distal radius/ulna in light field, as well as marker

lateral oblique wrist eval criteria

-Pisiform seen in profile if accurate obliquity -Extent of collimation depends on department protocol

AP forearm eval criteria

-Radial head, neck & tuberosity slightly superimposed over proximal ulna -Partially open elbow joint and open radio-ulnar articulation -Hand is supinated as evidenced by the radius NOT being superimposed over ulna, proximally.

PA axial scaphoid structures shown

-Tightly collimated image of scaphoid without self- superimposition from adjacent carpals -Distal radius and ulna and proximal half of MC's -Soft tissue and bony trabeculation

PA axial scaphoid, why ulnar deviation

-Ulnar deviation of the patient's wrist is important because it rotates the scaphoid parallel to the long axis of the forearm moving it away from the radius -Ulnar deviation rotates the scaphoid marginally in a palmar direction reducing the angle required to achieve an en face image -Ulnar deviated position pulls the scaphoid away from the radius; ulnar deviation also orientates the long axis of the scaphoid such that a tube angled towards the patent's elbow will not be angled across the scaphoid

wrist IR size

10 X 12

routine projections for wrist

PA Medial Oblique Lateral PA Axial for the Scaphoid (Stetcher Method) Lateral Oblique (DCMH only)

PA axial scaphoid eval critera

Scaphoid seen in it's entirety due to angulation of CR and ulnar deviation

for lateral and casts

increase kVP 4-6

shielding

lap shield

wrist/forearm cassette orientation

lengthwise

breathing

turn face away

wrist & forearm SID

40"

where do markers go

center edge lateral border

if a pediatric patient what must be done

AP and Lateral of opposite extremity

collimation

side to side 1/4 inch border

Which bone of the forearm articulates most directly with the humerus

Ulna

PA axial scaphoid CR position and location

-20 degrees towards elbow to enter the scaphoid near the anatomic snuff box -Align CR with midpoint of IR -Collimate tightly to scaphoid, include marker -Option: Use 20 degree angled board and direct CR perpendicularly

medial oblique eval criteria

-Scaphoid and trapezium seen if accurate obliquity -Extent of collimation depends on department protocol

PA wrist eval criteria

-Somewhat open inter-carpal joint spaces (depends on patient condition/ability) -Open wrist/radioulnar joints -Extent of collimation depends on department protocol

forearm IR size

14 X 17

routine projections for forearm

AP Lateral