New Formula for Calculating the Hounsfield Unit in CT Scan of Hard Tissue from Grey Scales in CBCT
Article Type:
Research/Original Article (دارای رتبه معتبر)

HU is a standard numbering system in CT, which is proportional to x-ray attenuation and an indicator of relative tissue density. In CBCT, the x-ray  attenuation degree is demonstrated with the grayscale. The present study aimed to  determine the correlation between the grayscale in CBCT and HU (Hounsfield Unit) in MDCT.

Materials and Methods

This descriptive-analytical study was approved under the ethics code of IR.GUMS.REC.1398.451. A human dry mandible was immersed in a transparent cylindrical container to simulate soft tissue attenuation. The sample was scanned at three separate imaging centers using three CBCT units with the same brand. The scans were carried out once with standard irradiation conditions and once with high-resolution conditions. The mandible was scanned with a CT scan unit. The grayscale and HU of the enamel, dentin, cortical, and spongy bone were evaluated and compared with each other. Pearson’s correlation coefficient was used for data analysis at a significance level of 5% (P<0.05).


In two standard and high-resolution conditions, there was a significant correlation (P<0.001) between the grayscale and HU. Given the positive values of the mean differences, it could be concluded that the gray level in CBCT has a positive correlation with HU in MDCT.


The grayscale in CBCT and HU in MDCT had a positive correlation, and according to this study, it is possible to calculate the HU from the gray level.

Journal of Dentomaxillofacil Radiology, Pathology and Surgery, Volume:11 Issue: 4, Autumn 2022
7 to 11  
دانلود و مطالعه متن این مقاله با یکی از روشهای زیر امکان پذیر است:
اشتراک شخصی
با عضویت و پرداخت آنلاین حق اشتراک یک‌ساله به مبلغ 990,000ريال می‌توانید 70 عنوان مطلب دانلود کنید!
اشتراک سازمانی
به کتابخانه دانشگاه یا محل کار خود پیشنهاد کنید تا اشتراک سازمانی این پایگاه را برای دسترسی نامحدود همه کاربران به متن مطالب تهیه نمایند!
  • حق عضویت دریافتی صرف حمایت از نشریات عضو و نگهداری، تکمیل و توسعه مگیران می‌شود.
  • پرداخت حق اشتراک و دانلود مقالات اجازه بازنشر آن در سایر رسانه‌های چاپی و دیجیتال را به کاربر نمی‌دهد.
In order to view content subscription is required

Personal subscription
Subscribe for 50 € euros via PayPal and download 70 articles during a year.
Organization subscription
Please contact us to subscribe your university or library for unlimited access!