Temporal bone imaging: comparison of flat panel volume CT and multisection CT

Abstract

Background and purpose: A recent development in radiology is the use of flat panel detectors in CT to obtain higher-resolution images. This technique is known as flat panel volume CT (fpVCT). We sought to compare the image quality and diagnostic value of 2 different flat panel detector-equipped scanners: one is a prototype fpVCT scanner, and the other is a so-called flat panel digital volume tomography (fpDVT) scanner, which is routinely used in clinical setup with current state-of-the-art multisection CT (MSCT) scanners.

Materials and methods: Five explanted temporal bones and 2 whole-head cadaveric specimens were scanned with fpVCT, fpDVT, and MSCT scanners. The image series were blindly evaluated by 3 trained observers who rated 38 anatomic structures with regard to their delineation/appearance.

Results: Although the image quality obtained with fpVCT and fpDVT was rated significantly better compared with MSCT on isolated temporal bones, the differences were not significant when whole cadaveric heads were scanned.

Conclusions: Theoretic and practical advantages exist for flat panel detector-equipped scanners, including improved image quality. However, when imaging whole cadaveric heads, no significant difference could be demonstrated between them and standard-of-care MSCT.

Fig 1.

Images of the incus, ambomalleolar joint, incostapedial joint, and the stapes in explanted temporal bone (TB) and whole-head specimens (WH) obtained by 3 different scanners.

Fig 2.

Images of the cochlea, vestibular duct, cochlear duct, and facial nerve in explanted temporal bone (TB) and whole-head specimens (WH).

Fig 3.

Three different examiners rated image quality with regard to delimitation of 38 different anatomic substructures as viewed in explanted temporal bones (TB) and whole-head (WH) specimens, each specimen being scanned with an MSCT scanner, an fpDVT scanner, and an fpVCT scanner.