Cervical spine imaging in trauma: Does the use of grid and filter combination improve visualisation of the cervicothoracic junction?

Abstract

Purpose To evaluate the usefulness of filter and anti-scatter grid combination in demonstrating the cervicothoracic junction in lateral cervical spine radiographs performed for trauma patients. Methods Following a change in departmental protocol in our hospital, anti-scatter grid and filter are routinely used for lateral cervical spine radiograph in all trauma patients with immobilised cervical spine. A retrospective study was done to compare the efficacy of lateral cervical spine radiographs in demonstrating the cervicothoracic junction for a period of three months before and after the implementation of the change. All images were independently evaluated by two observers. Results 253 trauma patients had a lateral cervical spine radiograph done in January to March 2003 without using the anti-scatter grid and filter while 309 patients in January to March 2007, using filter and grid. Inter-observer variability between the two observers was calculated using Cohen’s Kappa which showed good and very good agreement for 2003 and 2007 respectively. 126 (49.8%) images adequately demonstrated the cervicothoracic junction without using filter and grid while 189 (61.1%) were adequate following their use. This was statistically significant (Fischer exact test, p value = 0.0081). Conclusion The use of filter and anti-scatter grids improves the visualisation of cervicothoracic junction in lateral cervical spine imaging and reduces the need to repeat exposure.