Delineation of temporal bone anatomy: feasibility of low-dose 64-row CT in regard to image quality

Eur Radiol. 2007 Oct;17(10):2638-45. doi: 10.1007/s00330-007-0578-1. Epub 2007 Mar 7.


The aim of our present study was to evaluate the visualization of anatomical landmarks of the temporal bone using a low-dose 64-slice computed tomography (CT) technique. A total of 120 patients were evaluated, 60 patients (mean age 47.1 years; 36 male, 24 female) underwent examination with a 4-slice CT scanner: 180 mAs, 120 kV, 1 s rotation time, 2 x 0.5 mm collimation, 0.5 mm slice thickness. Another 60 consecutive patients (mean age 37.4 years; 43 male, 37 female) were examined using a 64-slice CT low-dose protocol: 140 mAs, 120 kV, 1 s rotation time, 12 x 0.6 mm collimation, 0.6 mm slice thickness. The visibility of 42 landmarks was scored by two blinded radiologists using a five-point quality rating scale. Mean equivalent dose was significantly lower for the 64-slice CT protocol (0.31 mSv +/- 0.12 mSv) compared to the 4-slice CT protocol (0.61 mSv +/- 0.08 mSv). Despite increased image noise, only 19% of the anatomical landmarks were delineated significantly better on the axial sections of the 4-slice CT and only 9.5% of the anatomical landmarks on the reformatted coronal images. The interobserver agreement did not differ significantly between the two modalities. Low-dose 64-slice CT technique facilitates temporal bone imaging with sufficient anatomical detail.

Publication types

  • Comparative Study

MeSH terms

  • Feasibility Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Radiation Dosage
  • Temporal Bone / anatomy & histology*
  • Temporal Bone / diagnostic imaging*
  • Tomography, X-Ray Computed* / methods