Foot (medial oblique view)

The medial oblique projection is part of the three view series examining the phalanges, metatarsals and tarsal bones that make up the foot. 

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
• the foot is medially rotated until the planter surface sits at a 45° angle to the image receptor

Technical factors 

• AP oblique projection
• centring point
  • x-ray beam centred to the base of the 3^rd metatarsal
  • the beam will be perpendicular to the image receptor 
• collimation
  • lateral to the skin margins
  • anterior to the skin margins of the distal phalanges
  • posterior to the skin margins of the calcaneum
• orientation  
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure
  • 50-55 kVp
  • 3-4 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

• superimposition is evident at the bases of the of 1^st and 2^nd metatarsals 
• there is no superimposition of the 3^rd to 5^th metatarsal
• base of the 5th metatarsal is free of superimposition from any structure 
• tarsal sinus is visible 
• joint spaces around the cuboid are open and equal
• cuboid is free of superimposition

Practical points

The metatarsal and tarsal bones are the most reliable rotation indicator.

If the foot is over rotated the base of the 5^th metatarsal will be superimposed by the tubercle of the 4^th metatarsal.

If the foot is under rotated the bases of the 4^th and 5^th metatarsals will overlap; the image may have a closer resemblance to the DP projection.