The use of ROI overlays and a semi‐automated method for measuring cortical area in ImageJ for histological analysis

A major part of histologic studies is the use of high resolution imaging for data collection and analysis. ImageJ, a freely available software from the NIH designed for image analysis, has many features that are not well‐known among bone histologists and can be incredibly beneficial in terms of stream‐lining data collection and maximizing limited resources. The aims of this technical note are twofold: (a) to describe methods for image annotation and measurement using region of interest overlays in ImageJ, and (b) to present a new code for a semi‐automated method of measuring cortical bone areas from high resolution cross‐sectional images also using ImageJ.