RESUMO
PURPOSE: Dark band (DB) artifact in head and neck computed tomography (CT) is caused by beam hardening (BH), and decreased CT values in the X-ray target become a problem. Therefore, we investigated whether it is possible to reduce DB artifact in the head and neck with a compensation filter. METHODS: We made 2 types of filters with alcohol and water. We set each of these filters in front of the chest phantom's clavicle and evaluated DB artifact. The evaluation method measured CT values in the DB artifact area and background (BG) area by changing each compensation filter thickness and the distance between the chest phantom's surface and each compensation filter. In addition, we measured average standard deviation (SD) in the BG area by the presence of each compensation filter. RESULTS: CT values in the DB artifact area were approximate to those in the BG area by setting the thickness of each compensation filter to more than 30 mm. Furthermore, these CT values were decreased by separating the distance between the chest phantom's surface and each compensation filter. Average SD in the BG area showed no significant difference between no filter and each compensation filter. CONCLUSION: It was possible to reduce DB artifact by a compensation filter for DB.