Diagnostic imaging assessment of the cervical spine is a challenge for even the experienced radiologist or practitioner. Patients may present with a broad spectrum of pathologies, including potentially catastrophic injuries requiring considerable interpretive prowess. While typical imaging modality use may identify most of the pathologies with which patients will present, particular attention to detail and use of multiple procedures may be required to identify complex or occult injuries. The ideal imaging tool would have perfect sensitivity and specificity to simplify this process, but no singularly superior diagnostic imaging tool exists. Rather, reasoning based on the patient history and most likely clinical scenarios dictate the decision making as to the diagnostic test of first choice and perhaps subsequently.
From a lateral view or in sagittal slices, gentle lordotic curves of the anterior and posterior margins of the vertebral bodies are to be present, forming a reference for continuity of the vertebrae and the connecting tissues. The anterior and posterior spinal lines allow basic comparison for vertebral positioning. The junctions of the laminae and spinous processes, representing the posterior border of the central canal, define the spinolaminar line and a third curvilinear reference. The vertebral bodies are rectangular with smooth, curved margins. The disk spaces are consistent and reveal like patterns of signal intensity on magnetic resonance imaging (MRI). The anterior aspects of spinous processes are in alignment, and the posterior tips of the spinous processes should be pointed in the same general direction (Mintz, 2004; Imhof and Fuchsjäger, 2002; Richards, 2005). The tips of the spinous processes form a fourth curvilinear reference, albeit used less frequently. The facet joints are paired at each level with the joint margins congruent and their spaces evident. The distance between the dens and anterior arch of the atlas remains consistent whether the image is in neutral or in a position of flexion or extension. Similarly, the aforementioned relationships of vertebra and disks remain relatively uniform throughout the spine with no disruption of the gradual curve regardless of position in the sagittal plane (Maus, 2002; Imhof and Fuchsjäger, 2002; Richards, 2005; Greenspan, 2000) (Figures 3–1 and 3–2).
A lateral view conventional radiograph of the cervical spine in a 37-year-old woman.
A sagittal slice MR demonstrating a normal-appearing cervical spine.
From anteroposterior (AP) or in coronal plane views, the vertebral bodies are aligned in a relatively vertical column. The uncinate processes and, thus, the uncovertebral joints are clearly visible. The spinous processes are positioned in the midline. Features such as the facet joints, transverse processes, and the pedicles are often difficult to distinguish on plain radiographs, but are similarly aligned, if visible (Maus, 2002; Imhof and Fuchsjäger, 2002; Richards, 2005...