Harald Brodoefel MD, Presenter: Nothing to Disclose

Andreas Korn, Abstract Co-Author: Nothing to Disclose

Benjamin Bender, Abstract Co-Author: Travel support, Bayer AG

Rafeeque A. Bhadelia MD, Abstract Co-Author: Nothing to Disclose

Peter Heiss MD, Abstract Co-Author: Nothing to Disclose

Ulrike Ernemann, Abstract Co-Author: Nothing to Disclose

While technical evolution of CT has primarily been oriented by improvement of speed, volume coverage and image quality, a continued rise in study numbers and heightened public awareness of radiation associated cancer risks have initiated a recent quest for significant reduction of radiation dose. A new CT detector with integrated electric components and shorter conducting pathways has recently been introduced to decrease system inherent electronic noise. The purpose of this study was to assess the potential benefit of such integrated circuit detector (ICD) in head CT by comparing objective and subjective image quality in low-dose exams with a conventional detector design (CDD).  

Using a conventional detector, reduced dose non-contrast head CT (255 mAs, effective dose 1.7 mSv) was performed in 25 consecutive patients. Following transition to ICD on the same CT scanner, 25 consecutive patients were scanned using identical imaging parameters. Data sets in both groups were reconstructed with iterative reconstruction (IR) and filtered-back-projection (FBP). Images were assessed in terms of quantitative (e.g. signal-to-noise ratio, contrast-to-noise ratio or image sharpness) and qualitative image quality (e.g. noise texture, overall image quality, artefacts).

Acquisition of head CT using ICD increased signal-to-noise ratio by 14% and 17% in grey (10.0±1.6 versus 11.4±2.5; p=0.02) and white matter (8.2±0.8 versus 9.6±1.5; p=0.0002). The associated improvement in contrast-to-noise ratio was 12% (2.0±0.5 versus 2.2±0.6; p=0.12). In addition, there was a 51% increase of objective image sharpness (582±85 versus 884.5±191 change in HU/Pixel; p<0.0001). Compared to standard acquisitions, subjective grading of noise as well as overall image quality scores were significantly improved with ICD (2.1±0.3 versus 1.6±0.3, p<0.0001; 2.0±0.5 versus 1.6±0.3, p=0.001). Streak artifacts in the posterior fossa were substantially reduced (2.3±0.7 versus 1.7±0.5; p=0.004).

At the same radiation level, acquisition of head CT with integrated circuit detectors achieves superior objective and subjective image quality.

Improvement of image quality through electronic noise reduction is additive to recent benefits from iterative reconstruction algorithms and the combination of strategies has the potential for further and significant reduction of patient dose.

Brodoefel, H, Korn, A, Bender, B, Bhadelia, R, Heiss, P, Ernemann, U, Performance of Integrated Circuit Detectors in Head CT: Objective and Subjective Image Quality in Comparison to Conventional Detector Design.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003897.html