* Rad Positioning (Pg. 136) Extremities of Hand and Wrist - 09/15/2025

What is the anatomic position for radiography

Standing upright feet together arms at sides palms forward

Which plane divides the body into equal right and left halves

Midsagittal plane

Which plane divides the body into equal anterior and posterior halves

Midcoronal plane

A plane angled to the long axis is called what

Oblique plane

What plane slices perpendicular to the long axis head-to-toe

Horizontal-transverse-axial plane

What line connects infraorbital margin to external auditory meatus

IOML (aka Reid's baseline)

Define anterior vs posterior

Front of body vs back of body

Define dorsal foot vs plantar surface

Dorsal top of foot vs plantar sole of foot

Palmar surface refers to what

Palm of the hand (anterior in anatomic position)

Supine vs prone

Supine on back vs prone on belly

Right lateral recumbent means what

Lying on right side

Why annotate "erect" or "upright" on chest images

Fluid-level assessment depends on patient posture

Lithotomy position definition

Hips and knees flexed legs abducted for GU access

Modified Sims is used commonly for what radiology task

Tip placement for enemas

How do you name obliques like LPO and RAO

Use side and surface touching the receptor

How do you name a decubitus view

Name by side down with horizontal beam

On decubitus which side do you mark with the R/L marker

Mark the upside

Best setup to show air-fluid levels

Patient upright with horizontal beam

If patient cannot stand how else can you show air-fluid levels

Use lateral decubitus with horizontal beam

PA vs AP chest which minimizes heart magnification

PA chest

Why does PA minimize magnification

Heart is closer to IR and central rays diverge less at object

What increases magnification more OID or SID change

Increased OID increases magnification

Define SID and OID

Source-to-image distance and object-to-image distance

Best way to reduce magnification if AP is unavoidable

Increase SID (e.g. move tube farther)

Define projection in radiography

Path of the beam through the patient to IR

What is an axial projection

Beam angled along the long axis of body part

What is a tangential projection used for

Skimming a curved surface (e.g. zygomatic arch)

Cephalic vs caudad tube angle

Cephalic toward head vs caudad toward feet

Transthoracic lateral humerus is described how

Lateral through thorax naming side against IR

What is the central ray rule for most parts

CR perpendicular to part and IR centered to middle of part

Why center to the middle of the part

Minimizes distortion from diverging side rays

Minimum number of projections for most exams

Two at 90° (one view is no view)

For long bones what should be included

Both adjacent joints when possible

Where should side markers be placed ideally

Lateral side away from anatomy of interest

When should you use a grid for extremities

Not needed if part thickness

Typical SID for upper extremity tabletop

40-48 inches

Define radiolucent vs radiopaque

Radiolucent allows X-rays through vs radiopaque attenuates

Handwashing and patient ID in lab test-outs matter how much

Miss either and it's a zero

Acronym "TB causes PMD WW" stands for what

Technique Bucky Collimate Ask-pregnancy Marker Diabetic Wristband verify Wash hands

Optimal kVp range for hand-wrist digits tabletop

~50-55 kVp

Why might EI/Exposure Index be unreliable on a single finger

Plate not exposed 30-40% so EI not representative

Best way to judge fine detail on digital images

Evaluate on diagnostic PACS monitor with magnification

Immobilization options for shaky extremity patients

Sponges tape radiolucent supports (e.g. pencil edge tissue-box edge)

Do not do what when positioning a painful hand

Do not grab or squeeze the injured area

Which oblique to reduce OID for digits 2-3

Medial rotation from PA

Which oblique to reduce OID for digits 4-5

Lateral rotation from PA

Lateral direction for digits 2-3 vs 4-5

Mediolateral for 2-3 vs lateromedial for 4-5

Why flex adjacent fingers for a single digit PA/oblique

To isolate injured digit and reduce superimposition

PA hand CR location

3rd MCP joint (center of hand)

What must be included on PA hand collimation

Fingertips through carpals with ~1 inch proximal to radiocarpal joint

Hand lateral preferred type and why

Fan lateral to separate phalanges

When to use karate-chop lateral of hand

When patient cannot separate fingers or metacarpal injury emphasized

Typical technique for PA/oblique hand

~2 mAs at 50 kVp (vendor dependent)

Typical technique adjustment for hand lateral

Increase kVp by ~5 (e.g. 2 mAs at 55 kVp)

Thumb lateral easiest sequence

From PA hand roll to lateral then finish with AP

Thumb CR location for dedicated views

First MCP joint

Thumb collimation must include which carpal

Include trapezium at CMC joint

Special view to evaluate 1st CMC (Bennett region)

Robert's view (aka AP thumb with 10-15° proximal angle)

Robert's view CR direction and point

Angle proximally 10-15° into 1st CMC joint

PA wrist finger position tip

Slightly flex fingers to bring carpals closer reduce OID

Wrist lateral alignment tip

Align palmar fat pad with dorsal fat pad true lateral

Orthopedic preference for wrist lateral joint space

Raise fingers ~15° or use 10-15° proximal tube angle

Scaphoid routine is ordered when

After wrist routine if scaphoid fracture is suspected

Scaphoid view 1 name and motion

Ulnar deviation (toward ulna)

How to find CR for scaphoid precisely

~3/4 inch distal to radial styloid then ~3/4 inch medial to that (snuffbox)

Scaphoid view 2 two equivalent options

10-15° proximal tube angle or elevate hand 20° (Stecher method)

Why elevate 20° for Stecher

Produces effective 10-15° angle at scaphoid with ulnar deviation

Do you perform both tube angle and hand elevation for Stecher

No choose one or the other

Define Colles fracture

Distal radius displaced posteriorly

Define Smith fracture

Distal radius displaced anteriorly

Which routine view best shows Colles or Smith displacement

Lateral wrist

Define Barton fracture

Fracture-dislocation of posterior lip of distal radius

Define Bennett fracture

Intra-articular fracture at base of 1st metacarpal

Most commonly fractured carpal in fall on outstretched hand

Scaphoid (navicular)

Why scaphoid fractures risk avascular necrosis

Proximal pole blood supply vulnerable (retrograde flow)

What indicates scaphoid injury on exam

Snuffbox tenderness

What is joint effusion and how best shown in trauma lateral

Fluid within joint capsule shown with horizontal beam or cross-table lateral

Osteoarthritis hallmark on hand X-ray

Joint-space narrowing osteophytes sclerosis

Rheumatoid arthritis hallmark on hand X-ray

Periarticular erosions and joint deformity often ulnar deviation

Bursitis imaging finding near joints

Calcific densities in tendon/bursa with limited ROM

Osteoporosis radiographic appearance

Decreased bone density fewer trabeculae increased lucency

Osteopetrosis radiographic appearance

Diffuse dense "ivory-bone" appearance brittle

Paget disease key technique change

Additive later stage increase technique

Osteomyelitis likely scenario in extremity

Diabetic foot with bone destruction needs prompt management

Pathologic fracture definition

Fracture through abnormal bone (e.g. tumor metastasis)

Metastatic bone disease common primaries

Breast lung prostate (among others)

Stress fractures early imaging pathway

X-ray often negative early consider NM bone scan or MRI

Arthrogram definition and common joint

Contrast study of a joint commonly the shoulder

CT role for wrist trauma

Excellent for occult fractures detail of carpal bones

MRI role for wrist trauma

Best for ligaments Triangular fibrocartilage complex and marrow edema

Nuclear medicine role in bone evaluation

Detects metastases and stress injury by increased uptake

Nørgaard (ball-catcher) view purpose

RA hands when PA cannot flatten fingers (45° semi-supinated both hands)

Rheumatology bilateral hand protocol

PA both hands on one image oblique both on one image lateral both on one image

When performing a PA hand how should fingers be spaced

Slight separation to avoid soft-tissue overlap

Where do you place the lateral side marker on a PA wrist

Thumb side (lateral side)

Why keep IR straight rather than kitty-wampus

Easier standardized reading and labeling

How tight to collimate on small parts like a digit

Collimate to area of interest with slight margin avoid excessive tight cropping

When centering a forearm AP where is CR

Mid-shaft to include wrist and elbow joints

What patient-care question must precede any exposure for women of childbearing age

Ask about pregnancy possibility

What extra history is critical for suspected infection or diabetic foot

Ask about diabetes wounds fever redness drainage