Indications for imaging
Evaluation of rib fractures, (note the demonstration of rib fractures without lung trauma rarely alters patient management) evaluation of anomalies seen on another projection, e.g. to localise lesions seen on a chest radiograph. The projection may be useful in the localisation of pleural tumours e.g. mesothelioma, (A rare neoplasm derived from the lining cells of the pleura and peritoneum which grows as a thick sheet covering the viscera.)

Anatomy  Demonstrated
Axillary portion of the upper ribs above the diaphragm.

Basic Position Patient
The patient stands erect facing the bucky, from here the patient is rotated 45degrees with the affected side away from the film, the arm of the affected side is raised and placed across the head which may need to be turned towards the affected side for comfort and ease of positioning.
Ensure the opposite site anterior chest wall is in contact with the bucky to aid immobilisation.
The erect anterior oblique position reduces the dose to breast tissue compared with the  posterior oblique, however the ribs are further from the film which may compromise image quality.

Left Anterior Oblique Chest Position

Meschan, I. 1955 An Atlas of Normal Radiographic Anatomy Saunders, London

Exposure Factors

Evaluation of the Image
ID and markers must be present and correct in the appropriate area of the film.
Limits of examination, superiorly the 1st rib, inferiorly the 12th rib, medially the spine, laterally the distal ends of the ribs and skin surface.
The elongated axillary portion of the ribs being investigated should be clearly seen.
There should be no evidence of respiratory movement.
The exposure should penetrate the cardiac shadow sufficiently to demonstrate detail in the ribs in its shadow, and the ribs below the diaphragm.

Rt Anterior Oblique Ribs