Cervical Spine - Lateral

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Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Cervical Spine - Lateral supine or erect
Area Covered	The cervical spine from C1 down to the C7-T1 joint space and approximately one-third of T1 the first thoracic vertebra
Pathology shown	Disruption to the 5 lines of stability, indicating possible fracture, arthritis
Radiographic Anatomy	Cervical Spine Radiographic Anatomy
IR Size & Orientation	24cm X 30cm Portrait
Film / Screen Combination	Regular (CR and DR as recommended by manufacturer)
Bucky / Grid	Moving or Stationary Grid
Filter	Can be used when using film
Exposure	70 kVp 20 mAs
FFD / SID	180 cm This larger distance helps overcome the OID (object to image receptor distance) to reduce magnification and improve the sharpness of the image.
Central Ray	Directed to the level of C4 Perpendicular to the IR If the patient has torticollis, a wry neck, then direct the central ray to the inner, concave side to use the diverging rays to help penetrate the intervertebral joint spaces
Collimation	Centre: C4 Shutter A: Open to include the top of the ear superiorly Shutter B: Open to include the soft tissue of the neck anteriorly The collimation may be angled to match the slope of the neck. For example, when the patient stands, C1 is usually more anterior than C7, so the collimation square may be tilted to match this slope.
Markers	Anterior to Cervical Spine clear of perivertebral soft tissues Marker orientation AP
Shielding	Gonadal (check your department's policy guidelines)
Respiration	Suspended respiration on expiration. The shoulders are able to relax downwards on expiration which will maximise the chances of being able to visualise the C7-T1 junction on the image.
Positioning	Ensure the removal of artefacts that may superimpose the anatomy of interest, such as earrings and other jewellery If the patient is erect, The patient is side on to the bucky/IR (usually left side is closest to the IR, however if the patient has torticollis, a wry neck, then direct the central ray to the inner, concave side) Position the midsagittal plane so that it is parallel to the IR Position the interpupillary line so that it is perpendicular to the IR (in an erect patient, this will also be parallel to the floor) Raise the chin slighlty, so that the mandible does not superimposed the cervical spine If the patient is supine, Position the patient so that the bucky/IR is along one side (usually the left side is closest to the IR) Position the midsagittal plane so that it is parallel to the IR. If the patient is on a barouche, then this is easily achieved by moving the bed. Position the interpupillary line so that it is perpendicular to the IR Only raise the chin slightly if the possibility of spinal injury has been ruled out, so that the mandible does not superimpose over the cervical spine Traction on arms may be required to see T1 Where possible ask the patient to relax their shoulders down and move their finger tips in the direction of their toes on expiration, so that as you expose you have the best chance of penetrating the lower cervical spine area
Critique PACEMAN	Positioning No rotation is evidenced by The posterior vertebral bodies are superimposed (see notes below) The zygopophyseal joints are seen open No tilt is evidenced by The intervertebral disc spaces of the cervical spine are all open (see notes below) No superimposition of the mandible over the cervical spine Area Covered All of the cervical vertebrae are shown, including spinous processes and the C7-T1 joint space and 1/3 of T1. Also the anterior soft tissue of the neck and airway are seen. Collimation Centre: C4 Shutter A: Open to show the EAMs superioly and the C7-T1 joint space and 1/3 of T1 inferiorly Shutter B: Open to show the soft tissue of the neck anteriorly, and the spinous processes of the cervical spine posteriorly Exposure Sufficient contrast and density to show the anterior soft tissue of the neck, including the airway. Minimal patient motion and sufficient contrast and density to show sharp, clear cortical margins and bony trabecular markings of the cervical vertebrae
Special Notes	The 5 lines of stability 1. Prevertebral (anterior) soft tissue 2. Anterior vertebral bodies 3. Posterior vertebral bodies 4. Spino-lamina line 5. Tips of spinous processes One line of disruption indicates a stable fracture Two or more lines of disruption indicate an unstable fracture Determining the direction of rotation The posterior vertebral bodies should be superimposed. If this is not the case, to determine the direction of rotation first identify which posterior vertebral body is magnified. This is the side that is furthest from the IR. You can then use this information to correct the positioning. For example, assume the patient is positioned so that the left side is closest to the IR/bucky and the posterior vertebral bodies are not superimposed. The left margin of the posterior vertebral body is sharper and less magnified, as it is closer to the IR. The right margin is further away and posterior. Therefore, correct the patient's position, bring the right side of the patient forward until the midsagittal plane is parallel to the IR/bucky. Intervertebral disc spaces Providing there is no pathology, with good positioning, the intervertebral disc spaces should be open all the way down, from C1 through to C7/T1 open across the vertebral body from anterior to posterior If not, check the position of the midsagittal plane interpupillary line central ray, especially where there is torticollis