Although supine oblique views detected many subluxations, they produced numerous false-negative and false-positive results. Significant differences in diagnostic accuracy were detected between the horizontal lateral and the supine oblique views to detect malalignment. The data for each projection were compared using alternative free-response operator characteristic and free-response forced-error methodologies. Blinded to experimental conditions, six observers evaluated every intervertebral level on each lateral and oblique image in isolation. Since each intervertebral level (C2-T1) was individually evaluated, the study sample consisted of 150 intervertebral segments. In the remaining 22 sets, there were 43 intervertebral segments with an abnormal anteroposterior displacement. Twenty-five sets of radiographs were obtained, of which three were normal. A normally aligned dry cervicothoracic vertebral specimen and the same specimen with varying degrees of subluxation at one or more levels were radiographed in anteroposterior, lateral, and 45° oblique projections, in a simulated supine position. This allows for discrepancies in the tilt of the head (flexion/extension of the cervical spine).To determine whether supine 45° oblique radiographs of the cervical spine can accurately detect and quantify anteroposterior intervertebral plane displacements, an observer performance study was performed. To achieve the best angle, the central ray should be directed at an angle that parallels the plane of the mandible and then directed to just below the hyoid bone. An excessive or insufficient angle can distort these disc spaces. To project the intervertebral disc spaces open, the central ray should be directed perpendicular to the long axis of the vertebral column 3, 4. This angle can and will vary between 5-20° depending on the position of the head. For this reason, a cephalic angle is required to project through the long axis of the vertebral column. Correcting tube angle errors and head tilt errorsĪ lordotic curvature exists in the cervical spine. The spinous process will rotate toward the pedicle of the side farther from the image receptor 3. The spinous process should be midline of the vertebral body, equidistant from both pedicles 3. Any deviation from the midline indicates rotation is present. Rotation can be detected by looking at the spinous processes in relation to the pedicles. make sure that any removable artifacts such as earrings, glasses or metal dentures are removed to avoid obscuring the anatomy of interest.spinous processes should be midline, equidistant to the pedicles, indicating that there is no rotation.cervical spine intervertebral disk spaces should be open 2.superiorly to include C2 and inferiorly to include T2. ![]() laterally to include the entire cervical spine.the central ray is midline centered at the level of C4 to enter immediately below the hyoid bone.chin should be raised to align the lower margin of the upper incisors to the mastoid tips/base of the skull (unless trauma when the patient is placed in a cervical collar).patient shoulders should be at equal distances from the image receptor to avoid rotation.patient positioned erect in AP position (unless trauma when the patient will be supine). ![]() This projection helps to visualize pathology relating to C3-C7 in the anatomical position, demonstrating any compression fractures, clay-shoveler fractures and herniated nucleus pulposus (HNP) 1.
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