In case of trauma, the standard UK protocol is to have a CT scan of the skull instead of projectional radiography. A skeletal survey including the skull can be indicated in for example multiple myeloma. Other axial skeleton The spine (that is, the vertebral column. A projectional radiograph of the spine confers an effective dose of approximately 1.5 mSv, comparable to a background radiation equivalent time of 6 months. Cervical spine: The standard projections in the UK AP and Lateral. Peg projection with trauma only. Obliques and Flexion and Extension on special request. In the US, five or six projections are common; a Lateral, two 45 degree obliques, an AP axial (Cephalad), an AP "Open Mouth" for C1-C2, and Cervicothoracic Lateral (Swimmer's) to better visualize C7-T1 if necessary. Special projections include a Lateral with Flexion and Extension of the cervical spine, an Axial for C1-C2 (Fuchs or Judd method), and an AP Axial (Caudad) for articular pillars. Thoracic Spine - AP and Lateral in the UK. In the US, an AP and Lateral are basic projections. Obliques 20 degrees from lateral may be ordered to better visualize the zygapophysial joint. Lumbar Spine - AP and Lateral +/- L5/S1 view in the UK, with obliques and Flexion and Extension requests being rare. In the US, basic projections include an AP, two Obliques, a Lateral, and a Lateral L5-S1 spot to better visualize the L5-S1 interspace. Special projections are AP Right and Left bending, and Laterals with Flexion and Extension. Pelvis - AP only in the UK, with SIJ projections (prone) on special request. Sacrum and Coccyx: In the US, if both bones are to be examined separate cephalad and caudad AP axial projections are obtained for the sacrum and coccyx respectively as well as a single Lateral of both bones. Ribs: In the US, common rib projections are based on the location of the area of interest. These are obtained with shorter wavelengths/higher frequencies/higher levels of radiation than a standard CXR. Anterior area of interest - a PA chest X-ray, a PA projection of the ribs, and a 45 degree Anterior Oblique with the non-interest side closest to the image receptor. Posterior area of interest - a PA chest X-ray, an AP projection of the ribs, and a 45 degree Posterior Oblique with the side of interest closest to the image receptor. Sternum. The standard projections in the UK are PA