Abstract
Panoramic radiography using a slit beam and film/screen receptor is standard for the emergency room evaluation of mandibular fractures and also in dentistry. This study compared the spatial resolution, area distortion factors, and the dosage considerations for a panoramic system where standard film/screen and a charge-coupled device were alternatively employed as the image receptor. Resolution and image contours were determined using a lead resolution grid positioned at selected beam projection angulations. Exposure measurements were carried out using a RANDO® average man phantom and a 3 cc beryllium-windowed ionization chamber. The maximum spatial resolution with film approached 5 lp mm−1 whereas with the CCD the maximum resolution was just above 4 lp mm−1. Consequently, the image layer was reduced slightly in width when using the CCD receptor. The use of the CCD resulted in a skin exposure reduction exceeding 70%.
Key words: Charge-coupled device (CCD), distortion, dosimetry, image layer, panoramic radiography, resolution
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