In the past, many authors have measured the PVST thickness on lateral cervical spine radiographs and obtained results that have a large overlap between normal and abnormal findings in patients. To our knowledge, an up-to-date evaluation of the PVST thickness on MDCT images has not been published. With the widespread replacement of standard radiographic evaluation of the cervical spine by MDCT, 4, 7– 10 it is necessary to establish normal values for the thickness of the PVST on MDCT images. In our experience, the normal values based on radiographic studies are commonly used in multidetector CT (MDCT) images, despite the fact that differences in the acquisition of these images could account for significant differences in their normal values. 1– 6 Analysis of the PVST is helpful in detecting subtle osseous or ligamentous injuries that might go unrecognized. The thickness of the prevertebral soft tissue (PVST) has long been considered a valuable radiographic measurement in evaluating possible injury to the cervical spine. We propose the obtained values as the upper limits of normal for PVST thickness on MDCT images in the adult population. The smallest variability and calculated SDs were found at C2 and C3.ĬONCLUSIONS: The thickness of the PVST is important in the detection of underlying injuries to the cervical spine. The upper limit of normal was not determined for C4 and C5 levels due to variable position of the esophagus and larynx. RESULTS: The upper limits of normal for the thickness of the PVST were 8.5 mm at C1, 6 mm at C2, 7 mm at C3, 18 mm at C6, and 18 mm at C7. Exclusion criteria included patients with a congenital or acquired (nondegenerative) abnormality of the cervical spine or PVST. Patients included in the study were not intubated, had an immobilized cervical spine, had normal findings on cervical spine CT, and did not have a diagnosis of osseous or soft-tissue cervical injury. MATERIALS AND METHODS: Thickness of the PVST was measured in 192 patients undergoing screening cervical spine MDCT with multiplanar reconstructions as part of a trauma protocol. Because the standard of care has shifted from radiographs to multidetector CT (MDCT), a re-examination of the PVST on MDCT images is needed to establish normal values for thickness appropriate for this imaging technique. Assessment requires a systematic approach.BACKGROUND AND PURPOSE: Analysis of the prevertebral soft tissue (PVST) is helpful in detecting osseous and ligamentous injuries of the cervical spine. The lateral view is often the most informative image. If the lateral view does not show the vertebrae down to T1 then a repeat view with the arms lowered or a ' Swimmer's view' may be required. In the context of trauma these images are all difficult to acquire because the patient may be in pain, confused, unconscious, or unable to cooperate due to the immobilisation devices. The 3 standard views are - Lateral view - Anterior-Posterior (AP) view - and the Odontoid Peg view (or Open Mouth view). Imaging should not delay resuscitation.įurther imaging with CT or MRI (not discussed) is often appropriate in the context of a high risk injury, neurological deficit, limited clinical examination, or where there are unclear X-ray findings. This is because normal C-spine X-rays cannot exclude significant injury, and because a missed C-spine fracture can lead to death, or life long neurological deficit.Ĭlinico-radiological assessment of spinal injuries should be managed by experienced clinicians in accordance with local and national clinical guidelines. Bones - Cortical outline/Vertebral body heightĬlinical considerations are particularly important in the context of Cervical spine (C-spine) injury.Alignment - Anterior/Posterior/Spinolaminar.Look at all views available in a systematic manner.Clinical considerations are of particular importance when assessing appearances of C-spine X-rays.Normal C-spine X-rays do not exclude significant injury.
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