Humerus (AP view)

The AP view of the humerus is part of the humerus series and is usually taken in a standing position. However, it can also be obtained in a supine position.

The projection demonstrates the humerus in its natural anatomical position allowing for adequate radiographic examination of the entire humerus and its respected articulations. 

Indications

Humerus views are often done to exclude large humeral shaft fractures or suspected symptomatic metastatic lesions ¹. If an occult fracture is suspected at either the proximal or distal end, it is best to do a separate elbow or shoulder series. 

Patient position

• the patient is preferably erect
• the patient's back is against the image receptor
• the affected arm is abducted and centered to the upright detector, if possible, the arm is slight externally rotated to mimic the true anatomical position

Technical factors

• anteroposterior projection
• centering point
  • mid humerus shaft
• collimation
  • superior to the skin margins above the glenohumeral joint
  • inferior to include the distal humerus including the elbow joint
  • lateral to include the skin margin 
  • medial to include skin margin 
• orientation  
  • portrait
• detector size
  • 35 cm x 43 cm
• exposure
  • 60-70 kVp
  • 7-15 mAs
• SID
  • 100 cm
• grid
  • yes (this can vary departmentally)

Image technical evaluation

The humerus is positioned AP, evidenced by the medial and lateral epicondyles seen in profile and the greater tuberosity being seen on the lateral aspect of the humerus. The shaft is abducted away from the patient's body, minimizing superimposition

Practical points

It is best to show the patient how you want their arm to rest for the projection. Often, you will have to rotate the light beam diaphragm to be aligned with the long axis of the humerus.