Objective: To evaluate the most reliable measurement method of the head circumference (HC) in brain magnetic resonance imaging (MRI).

Material and Methods: The MR images of 84 pediatric brain protocols with both axial T2-weighted image (T2-WI) and sagittal T1-weighted image (T1-WI) were retrospectively reviewed. The HC was independently measured in axial T2-WI and sagittal T1-WI by two radiologists before the data analyses. The reference method was obtained by semi-automatic software from the reconstructive images.

Results: Eighty-four patients were included. Both measurement methods had a strong positive correlation (r=0.981, 0.984) with the reference method. The mean difference between all methods was lower than the accepted value of error (2 cm). The second method, called 2D-axial with sagittal measurement, was more accurate than the first method, called 2D-axial measurement, compared with the reference method with a mean difference of 1.52 in radiologist 1 and 1.24 in radiologist 2. The interobserver agreement was good for all measurement methods with ICC of first and second methods being 0.98 and 0.99, respectively.

Conclusion: The second method, called 2D-axial with sagittal measurement, is more reliable than the first method, named 2D-axial measurement, to determine the head size in MR images using a simple application formula. Moreover, both methods are reliable to determine the head size in MR images with no limitation of the software.

Keywords: Head circumference; Magnetic resonance imaging

DOI: 10.35755/jmedassocthai.2022.11.13696

Received 24 January 2022 | Revised 26 September 2022 | Accepted 4 October 2022