Wrong conversion factor for CosMx

[AlbertoFabbri93]

The CellChat document Frequently Asked Questions when analyzing spatially resolved transcriptomics datasets states:

For CosMx data, the spatial coordinates are in pixels and the conversion factor of converting spatial coordinates from Pixels to Micrometers is 0.18. Because CosMx does not include the uniform cell size like 10X Visium and Slide-seq, users can compute the minimum cell centroid-to-centroid distance via computeCellDistance and use its half value as the tolerance factor. Of note, CellChat does not need an accurate tolerance factor, which is used for determining whether considering the cell-pair as spatially proximal if their distance is greater than interaction.range but smaller than “interaction.range + tol”.

But on the NanoString blogpost Comparing AtoMx™ SIP flat files with the legacy format they state:

The pixel edge length is 120 nm. Thus, to convert to microns multiply the pixel value by 0.12028 µm per pixel.

And, according to my tests, this is the only factor that gives distances that make sense. Can you please update your documentation?