Upper limb imaging Flashcards
Why do fractures happen?
- A fracture is the scientific and medical term for a break or crack in a bone
-They occur when there is a transfer of energy through a bone that exceeds what that bone can cope with
-Where a fracture occurs depends on two things – where the bone is weakest and where the majority of the force is applied
-This refers to the method by which an injury occurs
-Fall on outstretched hand, inversion, blunt trauma etc
-Fractures tend to follow patterns so the MOI can give us a hint as to what kind of fracture is most likely to have occurred
What is the SID (source image receptor distance) for upper limb x-rays?
- 100cm is the distance from tube to detector
Do we need to use grids for upper limbs?
- No
- Not a big enough area to generate enough scatter to justify the increased radiation dose
HAND – CLINICAL INDICATIONS
☢ OA/RA
☢ Trauma (Punch injury, FOOSH, stab wounds)
☢ Osteomyelitis
☢ ?Foreign Body (specific views – what are these?)
☢ Follow-up imaging
☢ Congenital abnormalities
Hand projections
Standard:
-DP
-Oblique
-Lateral
Additional
-Finger views
-Thumb
-Ballcatchers (Norgaard method)
Hand: DP patient position
- Patient seated at the side of the x-ray couch
- Elbow flexed; arm relaxed
- Palmer aspect of the hand placed on the image receptor
Hand: DP Centring points
- Central ray vertical to the image receptor
- Head of the 3rd metacarpal
Hand: DP Collimation
Laterally- include skin margins
Proximally- include distal radioulnar joint
Distally- include the tips of the distal phalanges
Fingers: DP Centring point
- Central x-ray vertical to the image receptor
- Between the heads of the two metacarpals (buddy fingers)
Fingers: DP Collimation
Laterally- lateral margins of both fingers and metacarpals
Proximally- include distal radioulnar joint
Distally- include the tips of the distal phalanges
Hand: DP Oblique Patient position
- Patient seated at the side of the x-ray couch
- Elbow flexed; arm relaxed
- Palmar aspect of the hand placed on the receptor image
- Rotate the hand laterally 45 degrees, ensuring the medial aspect of the hand is still in contact with the image receptor
Hand: DP Oblique Centring point
- Central ray vertical to the image receptor
- Head of the 3rd metacarpal
Hand: DP Oblique Collimation
☢Laterally – include skin margins
☢Proximally – include distal radioulnar joint
☢Distally – include the tips of the distal phalanges
Hand: Lateral Patient position
-Patient seated at the side of the x-ray couch
-Lateral aspect of affected hand in contact with the image receptor
-Palmar aspect of the hand 90 degrees to the image receptor
-Slightly abduct the thumb
Hand: Lateral Centring point
☢Central ray vertical to the image receptor
☢Head of the 2nd metacarpal
Hand: Lateral Collimation
Laterally- dorsal and palmar skin margins
Proximally- include distal radioulnar joint
Distally- include the tips of the distal phalanges
Fingers: Lateral Centring point
- Central ray vertical to the image receptor
- Over the proximal interphalangeal joint of the affected finger
Fingers: Lateral Collimation
Laterally- lateral soft tissue margins
Proximally- include metacarpophalangeal joint
Distally- include the tip of the distal phalanx
Hand top tips: Common error- Interphalangeal joint spaces are not clearly demonstrated. Why?
Fingers may be flexed; extend to clear
Hand top tips: Common error- Superimposition of soft tissue outlines of fingers. Why?
Fingers not seperated adequately
Hand top tips: Common error- Patients struggling to hold position, especially on the oblique view. Why?
Assist them with a small 30 degree sponge
Hand top tips: Common error- Extensive superimposition of the metacarpals of the oblique view
The Hand is externally elevated too much
Why is a ball catcher projection performed and what is its centring?
To see a different perspective of the joints.
-Anterior bilateral projection
-Centring: between the two hands at the level of the metacarpophalangeal joints
Thumb: PA Patient position
☢Patient seated at the side of the x-ray couch
☢Elbow extended
☢Posterior aspect of the thumb on the image receptor
Thumb: PA Centring point
- Central ray vertical to the image receptor
- Over 1st metacarophalangeal joint
Thumb: PA Collimation
Laterally- include all skin margins
Proximally- carpometacarpal joint
Distally- distal phalanx
Thumb: Lateral Patient position
☢Patient seated at the side of the x-ray couch
☢Elbow flexed; arm relaxed
☢Palmar aspect of the hand raised off the image receptor (can use pads to assist) so that thumb is lateral
Thumb: Lateral centring point
- Central ray vertical to the image receptor
- Over 1st metacarophalangeal joint
Thumb: Lateral Collimation
Laterally- include skin margins
Proximally- Carpometacarpal joint
Distally- distal phalanx
Wrist- Clinical indications
☢ OA/RA
☢ Trauma (FOOSH)
☢ Osteomyelitis
☢ ? Foreign Body
☢ Follow-up imaging
Wrist- projections
Standard projections
☢ DP
☢ Lateral
Additional projections
☢ Scaphoid projections – oblique/zitters or banana
☢ Oblique Wrist
Wrist- PA Patient position
☢ Patient seated at the side of the x-ray couch
☢ Elbow flexed; arm relaxed
☢ Palmar aspect of the hand placed on the image receptor but place fingers slightly curled (or over the top edge of the image receptor if not using a wallstand)
Wrist- PA Centring point
- Central ray vertical to the image receptor
- Midway between the radial & ulna styloid processes
Wrist- PA Collimation
Laterally- include skin margins
Proximally- distal 1/3 radius and ulna
Distally- heads of metacarpals
Carpal bones
scaphoid
lunate
triquetrum
pisiform
trapezium
trapezoid
capitate
hamate
Wrist: lateral Patient position
☢ From the PA position, externally rotate the arm until the ulnar aspect of the hand/wrist is in contact with image receptor
☢ Extend fingers
☢ Palmar aspect of the hand is perpendicular to the image receptor
Wrist: lateral Centring point
- Central ray vertical to the image receptor
- radial styloid process
Wrist: lateral Collimation
☢ Laterally – dorsal and palmar skin margins
☢ Proximally – distal 1/3 radius and ulna
☢ Distally – heads of metacarpals
PA wrist with ulnar deviation
☢ Position as for a PA wrist.
☢ Ulnar deviation of the wrist (laterally) as far as possible
PA Axial (Zitters/banana projection)
- Position as for PA wrist, angle tube 30degrees towards elbow
- Centre to the anatomical snuff box
- Ensure ulnar deviation
- 10 days after initial presentation – blood supply
Wrist- PA Oblique Patient position
- From the DP position externally rotate arm until ulnar aspect of the hand/wrist is in contact with the image receptor
-Palmar aspect of the hand/wrist 45degrees to the image receptor
- Support with 45degree radiolucent pad if necessary
- Extend fingers
Wrist- PA Oblique Centring point
- Central ray vertical to the image receptor
- Midway between the radial & ulnar styloid processes
Wrist- PA Oblique Collimation
☢ Laterally – include skin margins
☢ Proximally – distal 1/3 radius and ulna
☢ Distally – heads of metacarpals
RADIUS & ULNA – CLINICAL INDICATIONS
☢ Trauma (FOOSH, guarding)
☢ Osteomyelitis
☢ ? Foreign Body
☢ Follow-up imaging
☢ Imaging for fracture alignment
RADIUS & ULNA - PROJECTIONS
Standard projections
☢ AP/PA
☢ Lateral
Additional projections
☢ Joint specific projections if unclear from initial imaging
RADIUS & ULNA – AP Patient position
☢ Patient seated with affected side next to the x-ray couch without placing legs underneath
☢ Affected arm abducted and extended and placed on image receptor
☢ Arm supinated with wrist and elbow and shoulder in same horizonal plane
☢ Humeral epicondyles and styloid processes equidistant from imaging plate
RADIUS & ULNA – AP Centring point
- Central ray vertical to the image receptor
- Midway between the elbow and wrist
RADIUS & ULNA – AP Collimation
Laterally – include skin margins
Proximally – elbow joint
Distally – wrist joint
RADIUS & ULNA – LATERAL Patient position
☢ From the AP position, flex the elbow 90 degrees and medially rotate the arm so that the ulnar aspect is in contact with the imaging receptor
☢ Ensure wrist, elbow and shoulder are in the same transverse plane
☢ Palmar aspect of the hand should be 90 degrees to the image receptor
☢ Humeral epicondyles and styloid processes superimposed
Radius and ulna- lateral Centring point
- Central ray vertical to the image receptor
- Midway between the elbow and wrist
Radius and ulna- lateral Collimation
Laterally – include skin margins
Proximally – elbow joint
Distally – wrist joint
ELBOW – CLINICAL INDICATIONS
☢ OA/RA
☢ Trauma
☢ Pain & swelling
☢ Osteomyelitis
☢ ? Foreign Body
☢ Follow-up imaging
☢ Inability to straighten
ELBOW – PROJECTIONS
Standard projections
☢ DP
☢ Lateral
Additional projections
☢ Radial head views
ELBOW– AP Patient position
☢ Patient seated with their affected side next to the x-ray table without placing legs underneath
☢ Affected arm abducted and extended and placed on image receptor
☢ Arm supinated with wrist, elbow and shoulder in the same horizontal place
☢ Humeral epicondyles equidistant from image receptor
ELBOW– AP Centring point
Central ray vertical to the image receptor
Midway between humeral epicondyles and 2.5cm distally
ELBOW– AP Collimation
Laterally- include all skin margins
proximally- distal 1/3 of humerus
Distally- proximal 1/3 of radius and ulna
Elbow- Lateral Patient position
☢ From the AP position, flex the elbow to 90 degrees and medially rotate the arm so that the ulnar aspect is in contact with the image receptor
☢ Ensure the wrist, elbow and shoulder are in the same transverse plane
☢ Palmar aspect of the hand should be 90 degrees to the image receptor
☢ Humeral epicondyles superimposed
Elbow- Lateral Centring point
Central ray vertical to the image receptor
Over the lateral humeral epicondyle
Elbow- Lateral Collimation
Laterally- include all skin margins
proximally- distal 1/3 of humerus
Distally- proximal 1/3 of radius and ulna
HUMERUS – CLINICAL INDICATIONS
☢ Trauma
☢ Osteomyelitis
☢ ? Foreign Body
☢ Follow-up imaging
HUMERUS – PROJECTIONS
Standard projections
☢ DP
☢ Lateral
Additional projections
☢ Joint specific projections if unclear from initial imaging
HUMERUS – AP Patient position
☢ Patient is stood with their back to the image receptor.
☢ The arm is in the true anatomical position, palm facing forwards
☢ The posterior aspect of the upper arm should be in contact with the image receptor to reduce movement and magnification
HUMERUS – AP Centring point
Central ray horizontal to the image receptor
Middle of the humerus on the anterior aspect of the upper arm, midway between the shoulder and elbow joints
HUMERUS – AP Collimation
Laterally- include skin margins
Superiorly- The skin margin above the glenohumeral joint
Inferiorly- include the distal humerus including the elbow joint
HUMERUS – Lateral (PA) Patient position
☢ Patient is stood facing the image receptor
☢ The elbow is flexed so that the palm of the hand rests on the anterior abdominal wall
☢ The anterior aspect of the upper arm should be in contact with the image receptor to reduce movement and enlargement
☢ The patient should be rotated so that the lateral aspect of the shoulder of the affected side, the upper arm and elbow are all in contact with the image receptor
HUMERUS – Lateral (PA) Centring point
Central ray horizontal to the image receptor
(PA) Middle of the humerus shaft, on the medial aspect of the upper arm, midway between the shoulder and elbow joints
(AP) Middle of the humerus shaft, on the lateral aspect of the upper arm, midway between the shoulder and elbow joints
HUMERUS – Lateral (PA) Collimation
Laterally- include skin margins
Superiorly- The skin margin above the glenohumeral joint
Inferiorly- include the distal humerus including the elbow joint
SHOULDER – CLINICAL INDICATIONS
☢ Trauma
☢ Osteomyelitis
☢ ? Foreign Body
☢ Follow-up imaging
☢ OA
☢ Obvious deformity
☢ Limited ROM
SHOULDER - PROJECTIONS
Standard projections
☢ AP
☢ Axial
Additional projections
☢ Modified Axial
☢ Y-view Scapula
☢ Clavicle
☢ Acromioclavicular joint views
Shoulder- AP Patient position
☢ Patient is stood with their back to the image receptor
☢ The arm is in the true anatomical position with the palm facing forwards
☢ The patient is rotated 5-10 degrees towards the affected side (straight for trauma)
☢ The posterior aspect of the shoulder is in contact with the image receptor to reduce movement and magnification
Shoulder- AP Centring point
Central ray horizontal to the image receptor
Corocoid process
Shoulder- AP Collimation
Laterally- include skin margins
Superiorly- skin margins
inferiorly- include 1/3 of the proximal humerus
SHOULDER – Axial Patient position
☢ Patient is seated with the affected arm nearest to the image receptor
☢ The affected arm is abducted and ”stretched” across the image receptor
☢ The image receptor is underneath the axilla (the gleno-humeral joint over the image receptor)
☢ Legs should not be underneath the image receptor
☢ The head should be tucked towards the unaffected shoulder
SHOULDER – Axial Centring point
Central ray vertical to the image receptor
Head of the humerus
