Cervical - AP ("Wagging Jaw")

Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Cervical - AP ("Wagging Jaw")
Area Covered	Entire cervical spine with the mandible blurred
Pathology shown	Some pathologies of the entire cervical vertebrae including dens and surrounding bony structures of the C1 ring
Radiographic Anatomy	Cervical Spine Radiographic Anatomy
IR Size & Orientation	18 x 24 cm Portrait
Film / Screen Combination	Regular (CR and DR as recommended by manufacturer)
Bucky / Grid	Moving or Stationary Grid
Filter	No
Exposure	65 kVp 8 mA x 2 seconds - exposure time must be long enough to cover several complete excursions of the mandible to enable it to be blurred out
FFD / SID	100 cm
Central Ray	CR perpendicular to IR Directed to the level of C4
Collimation	Centre: C4, collimate to the 18 x 24cm film size Shutter A: Open so that the light of the collimated field just includes the top of the ear. The light will appear to bend around due to the central ray being angled cephalad Shutter B: Open to include the soft tissue of the neck laterally
Markers	Lateral Marker orientation AP
Shielding	Gonadal (check your department's policy guidelines)
Respiration	Suspended
Positioning	In general, Ensure the removal of artefacts that may superimpose the anatomy of interest Only request the patient move into position if the possibility of spinal injury has been ruled out Take care to ensure no rotation of either the head, neck or torso. If the patient is erect, Using the upright bucky, position the patient in an AP position. (This allows the patient to rest their back against the bucky, and may help to minimise patient movement) Position the midsagittal plane so that it is perpendicular to the IR Position the interpupillary line so that it is parallel to the IR (in an erect patient, this will also be parallel to the floor) Raise the chin slighlty, so that the line of the occlusal plane superimposes the base of the skull Mandible must be in continuous motion during exposure Ensure that only the mandible moves ( the head must not move and the teeth must not make contact) If the patient is supine, Position the IR patient so that it is either in the table bucky, or is on the barouche posterior to the cervical spine Position the midsagittal plane so that it is perpendicular to the IR Position the interpupillary line so that it is parallel to the IR Mandible must be in continuous motion during exposure Ensure that only the mandible moves ( the head must not move and the teeth must not make contact)
Critique PACEMAN	Positioning Area Covered Collimation Exposure
Special Notes