Indications for imaging
Trauma, bone pain, ?rickets, non accidental injury, leg length
assessment.
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Anatomy Demonstrated
Tibia and fibula including the knee and ankle joints.
Rt Tibia & Fibula AP Anatomy
Meschan, I. 1955 An Atlas of Normal Radiographic Anatomy
Saunders, London
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Basic Patient Position
The patient lies supine on the table with the long axis of the
tibia and fibula in line with the long axis of the table. If the
leg is positioned in true anatomical normal position with
neither the knee or ankle joint will be projected in the
"normal " AP position, therefore it is probably best
to position the joint nearest the suspected anomaly in correct
AP position, i.e. when the knee is in true AP position the ankle
will be internally rotated more than normal.
Lt Tibia & Fibula AP Patient Position
Meschan, I. 1955 An Atlas of Normal Radiographic Anatomy
Saunders, London
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Radiation protection
Direct lead rubber gonad protection using a "half
apron".
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Central Ray
The vertical central ray is directed midway between the lateral
and medial skin surfaces in the midshaft position to include
both joints.
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Exposure Factors
| Kv |
mAS |
FFD (cm) |
Grid |
Focus |
AEC |
Cassette |
| 65 |
5 |
100 |
No |
Fine** |
No |
35 x 43 cm* |
** The FFD may need extending to cover the full length with
small anode angles
* The cassette may need to be positioned diagonally to include
both ankle and knee joints.
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Evaluation of the Image
ID and markers must be present and correct in the appropriate
area of the film
Evidence of collimation on four sides equally around the
centering point.
Limits of the examination, superiorly the knee joint inferiorly
the ankle joint laterally and medially the skin surfaces. The
complete tibia and fibula should be demonstrated.
Optimal exposure should penetrate all the bone structures and
contrast should be low enough to visualise fully the bone and
soft tissue structures.
Lt Tibia & Fibula AP, Radiograph
http://www.vh.org/Providers/TeachingFiles/NormalRadAnatomy/Images/
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Related Projections
Tibia and fibula lateral
Knee and Ankle AP and Lateral
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Additional modalities
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