The dorsoplantar view is part of a three view series examining the phalanges, metatarsals and tarsal bones that make up the foot.
On this page:
Indications
This view demonstrates the location and extent of fractures in the foot, joint space abnormalities, soft tissue effusions and is the frontal view for the examination of foreign bodies.
Patient position
the patient may be supine or upright depending on comfort
the affected leg must be flexed enough that the plantar aspect of the foot is resting on the image receptor
Technical factors
AP projection
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centering point
x-ray beam centered to the base of the 3rd metatarsal
the beam must be angled approximately 10° posteriorly towards the calcaneum to mimic the arch of the foot, this may change if the arch is high or flat
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collimation
lateral to the skin margins
anterior to the skin margins of the distal phalanges
posterior to the skin margins of the calcaneum
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orientation
portrait
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detector size
18 cm x 24 cm
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exposure
50-55 kVp
3-4 mAs
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SID
100 cm
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grid
no
Image technical evaluation
1st metatarsal has even concavity
the spaces between the 2nd to 5th metatarsal are equal, yet the bases are overlapping
intertarsal space between the medial and intermediate cuneiform should be open
Practical points
The bases of the metatarsals and the tarsal bones are the most reliable rotation indicator on the DP view.
If the foot is over rotated externally, the metatarsal bases will be heavily superimposed whilst the tuberosity of the navicular bone can be seen in profile.
Over rotation internally will open up the metatarsal bases and the resultant image will bear close resemblance to the medial oblique projection.
In the scenario where the DP is ordered to query a foreign body, do not angle the x-ray beam to mimic the arch as this will result in elongation of the foreign body in question.
In trauma, the patient may not be able to flex the affected knee to the desired angle. In this case, a triangular wedge can be placed under the foot. The same principle of angling posteriorly to mimic arch applies. With the foot resting at 10-15° less of an angle is required.