Justify tech- Adaptive technique workshop Flashcards
For the AP elbow:
IR without a grid placed vertically against the posterior aspect of the elbow held with an IR holder
With a 10° external angle applied to IR
Horizontal central ray with a 10° posterior angle and a 15° cranial angle. 115cm SID
Centred 2.5cm distal to the midpoint of the medial and lateral epicondyles
Collimated to include the distal ½ of the humerus and proximal ½ of the radius and ulna, medial and lateral borders of arm
9 year old boy
Left elbow x-ray
Clinical history: fall from swing, obvious deformity,
?# distal humerus
IR without a grid placed vertically against the posterior aspect of the elbow held with an IR holder
With a 10° external angle applied to IR
? Supracondylar therefore must not move arm
AP elbow would ideally have the IR in contact with the posterior aspect of the elbow. This can only be achieved without movement by placing the IR vertically, ensuring it is held stable to prevent movement and potential injury to the patient
Arm could be raised on pads, but this would involve movement and the IR can positioned low enough that the medial aspect of the elbow will be demonstrated on the resultant image.
10° external angle of IR matches the external angle of the arm and enables to epicondyles to be equidistant from the IR
No grid is needed due to small volume of tissue being imaged; as only limited scatter is produced not adversely affecting the resultant image
Horizontal central ray with a 10° posterior angle and a 15° cranial angle
10° posterior angle reflects the external angle of the arm and IR
15° cranial angle reflects the abduction of the shoulder to ensure a perpendicular relationship to the arm and IR
Centred 2.5cm distal to the midpoint of the medial and lateral epicondyles
This is the standard centring point for an AP elbow
Collimated to include the distal ½ of the humerus and proximal ½ of the radius and ulna, medial and lateral borders of arm
This is wider collimation than normal, only 1/3s are required normally. The obvious deformity appears to be quite proximal to the shoulder; increasing the AOI will ensure that the fracture is fully demonstrated on the first image hopefully preventing need for repeats
For the lateral wrist:
Wrist placed on a radiolucent pad
IR without a grid placed vertically against the lateral aspect of the wrist held with an IR holder
Horizontal central ray at 115cm SID
Centred over the ulnar styloid process
Collimated to include the distal ½ of the of the radius and ulna, metacarpals, anterior and posterior skin borders of arm
35 year old female
Left wrist x-ray
Clinical history: fall from height.
Obvious deformity and open fracture
Wrist placed on a radiolucent pad
This raises the wrist from the table enabling the anterior aspect of the wrist to be visualised on the IR
IR without a grid placed vertically against the lateral aspect of the wrist held with an IR holder
Due to the open fracture and significant deformity, the patient will not be able to rotate their arm to achieve a standard lateral wrist projection.
Lateral wrist would normally have the IR in contact with the medial aspect of the wrist. However, placing the IR on the lateral aspect will allow more room for movement of the tube without possibly hitting the patient with the tube
A lateral wrist projection will still be obtained as the relationship of the carpal bones and radius and ulna with the IR and Cr are unchanged.
Horizontal central ray at 115cm SID
This ensures a 90° relationship between the IR and central ray
115cm is the standard SID; the IR can be placed in contact with the wrist so there is no need to change SID to prevent magnification
Centred over the ulnar styloid process
Standard centring for a lateral wrist is the medial styloid process; as the IR is on the medial aspect the lateral styloid is used instead
Collimated to include the distal ½ of the of the radius and ulna, metacarpals, anterior and posterior skin borders of arm
Collimation to MCs and skin borders is standard for a lateral wrist and does not need changing for this projection.
It is normal to collimate to the distal 1/3 of the radius and ulna but increasing this to distal ½ will ensure that the entire fracture is demonstrated on one image making it easier to assess alignment.
For the AP ankle:
Pillow removed from under leg
IR without a grid placed flat on the trolley under the ankle, displaced medially.
Medial aspect of IR raised with pads
Vertical central ray with a 20° medial angle at 115cm SID
Centred between the medial and lateral malleoli
Collimated to include the distal ½ of the of the tibia and fibula, tarsus, medial and lateral skin borders
Clinical details
28 year old female
Left ankle x-ray
Clinical history: fall; obvious deformity
For the AP ankle:
Pillow removed from under leg
This ensures a flat surface for the IR to be placed on, more easily enabling a perpendicular relationship with the CR
IR without a grid placed flat on the trolley under the ankle, displaced medially
Medial aspect of IR raised with pads
The patient was obviously unable to rotate their leg internally to bring the malleoli equidistant from the flat IR
A medial angle of the Cr is therefore required to replicate the internal rotation
The medial displacement of the IR ensures the ankle will not be projected off the IR as a medial angle is required.
Raising the medial aspect of the IR will bring it closer to a 90° relationship with the CR once the tube is angled, reducing distortion of the resultant image.
Vertical central ray with a 20° medial angle at 115cm SID
The 20° medial angle replicates internal rotation and ensures a 90° relationship between the malleoli and central ray
No change from standard SID is needed as there will be good contact between the ankle and IR.
Centred between the medial and lateral malleoli
Standard centring for an AP ankle
Collimated to include the distal ½ of the of the tibia and fibula, tarsus, medial and lateral skin borders
Collimation to tarsus and skin borders is standard for an AP ankle and does not need changing for this projection.
It is normal to collimate to the distal 1/3 of the tibia and fibula but increasing this to distal ½ will ensure that the entire fracture is demonstrated on one image making it easier to assess alignment.
