Improving Depiction of Temporal Bone Anatomy With Low-Radiation Dose CT by an Integrated Circuit Detector in Pediatric Patients

Abstract

The purpose of this study was to determine the performance of low-dose computed tomography (CT) scanning with integrated circuit (IC) detector in defining fine structures of temporal bone in children by comparing with the conventional detector.The study was performed with the approval of our institutional review board and the patients’ anonymity was maintained. A total of 86 children <3 years of age underwent imaging of temporal bone with low-dose CT (80 kV/150 mAs) equipped with either IC detector or conventional discrete circuit (DC) detector. The image noise was measured for quantitative analysis. Thirty-five structures of temporal bone were further assessed and rated by 2 radiologists for qualitative analysis. κ Statistics were performed to determine the agreement reached between the 2 radiologists on each image. Mann–Whitney U test was used to determine the difference in image quality between the 2 detector systems.Objective analysis showed that the image noise was significantly lower (P < 0.001) with the IC detector than with the DC detector. The κ values for qualitative assessment of the 35 fine anatomical structures revealed high interobserver agreement. The delineation for 30 of the 35 landmarks (86%) with the IC detector was superior to that with the conventional DC detector (P < 0.05) although there were no differences in the delineation of the remaining 5 structures (P > 0.05).The low-dose CT images acquired with the IC detector provide better depiction of fine osseous structures of temporal bone than that with the conventional DC detector.

Imaging of the temporal bone in children using low‐dose 320‐row area detector computed tomography

“…He et al . showed that the CTDI vol and DLP for 128‐section low‐dose CT with an integrated circuit (80 kV, 150 mAs) were 9.8 mGy and 42 mGy·cm, respectively, in children aged younger than 3 years . A tube voltage of 80 kV was used in both these studies, and has been reported to be associated with higher image contrast for temporal bone CT than a tube voltage of 120 kV and to improve the image quality using the low‐dose protocol .…”

“…There is limited information on low‐dose CT of the temporal bone in children, and our search of the English literature revealed no study assessing the image quality of 320‐row temporal bone CT in clinical practice. We believe that information on the performance of low‐dose temporal bone CT would be helpful for institutions seeking to reduce radiation exposure.…”

“…Since there was no diagnostic reference level for paediatric temporal bone CT, we revised our CT protocol for temporal bone based on the study by Bauknecht et al The tube current was reduced stepwise while maintaining image quality to obtain a low-dose protocol (120 kV, 50 mAs). When reducing the radiation dose, we used the degree of visibility of the stapes and bony lamella of the cochlea as indicators of image quality following the suggestion of Naucer et al 5 There is limited information on low-dose CT of the temporal bone in children, 5,6 and our search of the English literature revealed no study assessing the image quality of 320-row temporal bone CT in clinical practice. We believe that information on the performance of lowdose temporal bone CT would be helpful for institutions seeking to reduce radiation exposure.…”

Imaging of the Pediatric Temporal Bone Abnormalities

“…There is again high signal on T2, in the center of the lesion, with the occasional presence of peripheral low signal rim (►Fig. 4). Faint peripheral enhancement may be seen uncommonly on postcontrast images.…”

“…One such example is the integrated circuit detector that reduces crosstalk between detectors, thereby reducing image noise and improving spatial resolution, and ultimately, offering the potential to reduce dose. 4…”