Series metadata image laterality

Hello, I am currently making segmentations in a Tomosynthesis series of images and I would like to know which series is the left breast or the right breast. That’s when I looked for the series metadata. Then I found “PatientOrientation” which says for example “[2] P, FL”. Is that related to left and right? Or which one of the metadata is the one that provides me the laterality of the image? Thank you.

It may vary depending on how the vendor implemented the standard, but PatientOrientation should describe only the relationship of the patient to the scanner (Patient Position Attribute – DICOM Standard Browser), while Laterality (Laterality Attribute – DICOM Standard Browser) should be used to describe which side of the body is being imaged.

The laterality information (which breast) is distinct from the orientation information (which direction the rows and columns of the image point relative to the patient).

For the Breast Tomosynthesis IOD, which is of the enhanced multi-frame family, such anatomical information is in the Frame Anatomy Sequence in Frame Laterality, which is usually in the Shared Functional Group Sequence, since all frames in a single instance are (usually) of the same breast.

I.e., it is not in the top level dataset, and not in Laterality or Image Laterality (the later being used for ordinary, non-tomographic mammography images).

There are examples in IDC such as this one, and you can use the Tag Browser in OHIF to see the Frame Laterality.