Selecting connectivity data with injection into particular hemisphere

Hi,

I am trying to filter out unionized connectivity data based on the hemisphere which the injection was made into. For example, both experiments with ids 272699357 and 267029447 were injected into structure with id 795 (Periaqueductal gray). To retrieve data, I make the ProjectionStructureUnionize RMA query in Python, specifying is_injection as True and section_data_set_id as the experiment id. Then I select data by specifying the structure of interest (id 795). This gives:

Exp 272699357

hemisphere_id normalized_projection_volume structure_id max_voxel_x max_voxel_y max_voxel_z
8 1 0.043593 795 9570 3110 5640
43 3 0.689372 795 9570 3110 5640

Exp 267029447

hemisphere_id normalized_projection_volume structure_id max_voxel_x max_voxel_y max_voxel_z
26 2 0.814914 795 8620 3820 5870
44 3 0.814914 795 8620 3820 5870

Why is the projection data in the entry with hemisphere_id = 3 equal to the other entry for one experiment and different for another (identical max voxel coordinates suggest it’s the same injection)? Some of the other experiments I’ve tested do not have entries with hemisphere_id other than 3. How do I make sense of this?

What is the best approach for making sure that the injection sites of several experiments are located in a specified hemisphere?

Thank you!