Wrist/Forearm

Body/Shaft of Radius

Radial Tuberosity

Narrowing

Radial Neck

Radial head

Body of Ulna

Ridge

Coronoid process

The End

Olecranon process

Distal Humerus

Radius articulates with humerus on lateral aspect with 

Capitulum

Ulna articulates with 

Trochlea

What is on lateral aspect 

Lateral epicondyle 

What is on medial aspect

Medial epicondyle

Dark spot ( indent so less bone) ( more radiolucent) (posterior aspect of humerus) 

Olecranon fossa

Radius 

• Bigger on distal aspect on lateral 

Ulna

• Bigger on proximal aspect on lateral 

Humerus

On lateral we cannot see

Radial Tuberosity

• lives on medial aspect 

Radial neck

Radial head

Olecranon process

(blue) 

Coronoid process

Where Coronoid process and Olecranon process meet and also indentation 

Trochlear notch / Semilunar notch 

Shaft of Humerus 

Red- Trochlear notch Blue is what you are looking at 

Capitulum , Trochlea , & Trochlear sulcus 

• Superimposing in three circles

Good forearm

• Wrist and an elbow included with soft tissue

Ulna on left side & Radius on right side → No rotation

• slight overlap on AP

Ulna on left side & Radius on right side → Lateral rotation on AP

Right AP forearm

• Separation not touching/no overlap

Ulna on left side & Radius on right side → Medially rotated on AP 

This is right forearm AP

• Lots of overlap

• Coronoid process moved medially

How to tell it’s a good AP → No rotation

Distal Portion 

• Nice separation on metacarpals

• evaluation of  carpal bones → they are all laid out 

• Distal Radioulnar joint → No overlap 

Proximal Portion 

• Slight overlap of Radial head, neck and tuberosity with the Ulna

Medial/internal Rotation in AP

Distal Portion:

• Overlap of carpal bones they are coming together → See medial aspect better than lateral

• Pisiform separating from other carpal bones

• 4th and 5th metacarpal no overlap of the heads , space b/w shafts are closer and slight overlap of the bases

• Distal radioulnar joint starts to overlap 

Proximal Portion:

• Lots of overlap of Radial head, neck and tuberosity with the Ulna

External/Lateral rotation in AP

Distal Portion:

• 3rd-5th metacarpals start to overlap

• Trapezium and scaphoid you can see better

• Overlap of the Distal Radioulnar joint

Proximal portion:

• Very little superimposition of the radius and ulna 

4th and 5th big metacarpal separation

• Medially rotated cause it’s an AP

If you have lateral rotation in the wrist you will see

Radial tuberosity on the anterior aspect

• radius and ulna CAN appear superimposed

Fat pad sits adjacent to the

Joint capsule

Why do we want to see the fat stripe? 

So if the joint is swelling due to Joint effusion (joint fluid)

• It’s gonna press on that fat stripe and make it noticeable to the doctor

What deviation is this

Ulnar deviation

• We see the scaphoid better

What deviation is this?

Radial deviation

• We see the Lunate , Triquetrum, Pisiform and Hamate better

Wrist Exam Criteria 

Multiple: 

• PA & 45 degree oblique ( 8×10 CW)

• Lateral 8×10 LW

Single:

• 1 on 1 8×10 LW

PA or PA Axial Scaphoid

• 8×10 LW

kV: 60-70

SID: minimum 40 inches 

Another reason for Ulnar Deviation

• Flattens the scaphoid as it is naturally tilted

Why use angle or sponge for navicular view?

• Foreshortened if no angle

• Allows to see scaphoid ( ← angled and tilted in wrist ) properly

Why do we curl our fingers during PA wrist

wrist and carpal area gets closer to IR

• CR perpendicular to midcarpals

45 degree lateral oblique wrist criteria

• CR to midcarpals

• Anatomy: Distal radius, ulna , carpals and metacarpals.

• Support wrist to eliminate motion 

Wrist special projections ?

Scaphoid projections:

• PA axial w/ ulnar deviation 

• Modified stretcher method 

Tangential-carpal canal 

PA axial w/ ulnar deviation

• Angle tube 10-15 degrees proximally towards elbow

• ulnar deviation 

• CR to scaphoid ( ¾ inch distal and medial to radial styloid process) 

If you can’t angle or patient can’t deviate → Modified stretcher method ( Hand elevated 20 degrees no deviation)

• CR perpendicular to scaphoid

If you can’t angle → Modified stretcher method ( Hand elevated 20 degrees with deviation)

• CR perpendicular to scaphoid

Tangential-carpal canal method ( Tangential , Inferosuperior projection)

• CR 25-30 degrees to hand

• Rotate hand & wrist 10 degrees towards radius → so Pisiform and Hamate aren’t superimposed

• Pull back with tape so fingers aren’t in the way of central ray 

• Center proximal to base of 3rd metacarpal 

• 8×10 IR 

Olecranon Fossa is part of ?

Humerus

Olecranon Process is part of ?

Ulna

In AP position the Trochlear notch is in b/w

Coronoid process and Olecranon process

Ulna indent is what

Trochlear notch

Humerus indent

Trochlear Sulcus

Trochlear Sulcus ( groove) is part of the 

Humerus

Trochlear notch is holding part of

the humerus that is sitting in the notch

Trochlear notch/Semilunar notch is part of the

Ulna

Radial head is the most

proximal part of the radius

Radial Tuberosity lives

Medially and slightly anterior on Radius

Radius articulates w/ distal Humerus on the

Lateral aspect

Positioning of Forearm exam criteria 

• 2 exposures on one IR or 1 on 1 

• 11×14 lw for smaller patients ( This depends on length of bones ) 

• 14×17 lw for large patients 

• Collimation: include min 1 inch beyond wrist and elbow joints

• SID : 40 inches

• Non-grid

• kV: 65-75

AP forearm 

• shoulder, elbow and wrist same plane 

• Hand supinated 

• Humeral epicondyles parallel to IR ( DON’T FOCUS WE WILL LEARN LATER) 

• elbow and wrist joints included

• CR to mid forearm 

• Don’t forget we naturally medially rotate our arms when reach out so lean on side of interest

AP forearm image analysis Criteria : Position

Position:

• Long axis of forearm aligned with long axis of IR

• No rotation → look at Radial head , neck and tuberosity → Should be slightly superimposed by the Ulna ( no more than quarter of an inch)

• Olecranon process situated w/ olecranon fossa ← Just telling us if arm is extended

AP forearm image analysis Criteria : Collimation & CR

Collimation:

• Collimation to skin margins along length of forearm

• Include both wrist and elbow joints (1-1.5 inches)

• CR to midpoint of forearm (radius & ulna)

Lateral Forearm

• Shoulder , wrist and elbow on same plane

• Epicondyles perpendicular to IR

• Elbow 90 degrees

• Wrist true lateral

• CR to mid forearm

On Lateral Position → Radius is ___________ on distal aspect 

Ulna is ___________  on proximal aspect 

Bigger

Ap forearm we mark the 

Lateral side and position that first

Lateral forearm image analysis Criteria : Position

• 90 degrees

• everything on same plane 

• No rotation: head of ulna superimposed over the radius ( that’s the wrist ) 

• Radial head superimposed with coronoid process

Lateral forearm image analysis Criteria : Collimation & CR

• Collimation to skin margins along length of forearm

• Include both wrist and elbow joints (1-1.5 inches)

• CR to midpoint of forearm (radius & ulna)

What rotation is this? 

Lateral/external rotation 

• if you have external rotation in wrist you will most likely see the radial tuberosity

• pisiform is popping out and anterior to scaphoid 

What projection/position is this?

PA wrist (right)

What projection/position is this?

PA external oblique wrist (left)

This is an oblique wrist what rotation does it have ? Not a good image

Medially rotated like PA

corrective action: externally rotate wrist to 45 degrees

What rotation does it have? ( Lateral wrist)

Medially rotated

• relationship of ulna and radius

• scaphoid anterior to pisiform

corrective action: Externally rotate to 90 degree angle

What rotation does it have? ( Lateral wrist)

Medially rotated

• relationship of ulna and radius

• scaphoid anterior to pisiform

corrective action: Externally rotate to 90 degree angle

What rotation does it have? ( Lateral wrist)

Externally rotated

• pisiform anterior to scaphoid

• relationship of ulna and radius

• 5th metacarpal anterior to 2nd metacarpal

Corrective action: medially rotate to 45 degree angle

Carpal canal radiograph what are the bones

a.

d.

e.

f.

h.

A. scaphoid

d. Pisiform

e. Trapezium

F. trapezoid

h. hamulus