Affiliations: Radiological Center, National Defense Medical College
Hospital, Tokorozawa, Saitama, Japan | Division of Health Sciences, Graduate School of
Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan | Department of Radiology, Maebashi Red Cross Hospital,
Maebashi, Gunma, Japan | Department of Radiological Technology, Toranomon
Hospital, Minato-ku, Tokyo, Japan | Department of Radiology, National Defense Medical
College, Tokorozawa, Saitama, Japan
Note: [] Corresponding author: Satoshi Takagi, Radiological Center,
National Defense Medical College Hospital, 3-2, Namiki, Tokorozawa, Saitama,
359-8513, Japan. Tel.: +81 4 2995 1511; Fax: +81 4 2995 0633; E-mail:
rt.stakagi@gmail.com
Abstract: BACKGROUND: The hybrid convolution kernel technique for computed
tomography (CT) is known to enable the depiction of an image set using
different window settings. OBJECTIVE: Our purpose was to decrease the number of artifacts in
the hybrid convolution kernel technique for head CT and to determine whether
our improved combined multi-kernel head CT images enabled diagnosis as a
substitute for both brain (low-pass kernel-reconstructed) and bone (high-pass
kernel-reconstructed) images. METHODS: Forty-four patients with nondisplaced skull fractures were
included. Our improved multi-kernel images were generated so that pixels of
>100 Hounsfield unit in both brain and bone images were composed of CT
values of bone images and other pixels were composed of CT values of brain
images. Three radiologists compared the improved multi-kernel images with bone
images. RESULTS: The improved multi-kernel images and brain images were
identically displayed on the brain window settings. All three radiologists
agreed that the improved multi-kernel images on the bone window settings were
sufficient for diagnosing skull fractures in all patients. CONCLUSIONS: This improved multi-kernel technique has a simple
algorithm and is practical for clinical use. Thus, simplified head CT
examinations and fewer images that need to be stored can be expected.
Keywords: Combined multi-kernel, head computed tomography, reconstruction kernel, window settings
