Flat-panel CT versus 128-slice CT in temporal bone imaging: Assessment of image quality and radiation dose

We compared the image quality and radiation dose of flat-panel CT (FPCT) and multi-slice CT (MSCT) performed respectively with an angiographic unit and a 128-slice CT scanner. We investigated whether the higher spatial resolution of FPCT translated into higher image quality and we sought to eliminate inter-subject variability by scanning temporal bone specimens with both techniques.

Fifteen temporal bone specimens were imaged with FPCT and MSCT. Two neuroradiologists experienced in otoradiology evaluated 30 anatomical structures with a 0-2 score; 18 structures important from a clinical perspective were assigned a twofold value in calculation of the overall score. The radiation dose was calculated through the use of an anthropomorphic phantom.

The image quality was significantly higher for FPCT than MSCT for 10 of the 30 anatomical structures; the overall score was also significantly higher for FPCT (p = 0.001). The equivalent dose of the two techniques was very similar, but with different effective doses to the organs.

FPCT performed on an angiographic unit provides higher image quality in temporal bone assessment compared to MSCT performed on a 128-slice CT scanner thanks to its higher spatial resolution, with comparable equivalent doses but different effective doses to the organs.