Hi Bruce,

As per this paper: https://elifesciences.org/articles/29285#abstract (Figure 1—figure supplement 4), Local GI is ratio of two quantities and as per this http://en.citizendium.org/wiki/Gyrification, GI is also ratio of two quantities.

So both GI and LGI should be 'unitless' as per these papers. But again, e.g. http://www.sciencedirect.com/science/article/pii/S2213158215000856 indicates GI in 'mm'.

Are there any typos or I am misunderstanding something here?

Thanks.

On Fri, Dec 22, 2017 at 8:45 PM, Bruce Fischl fischl@nmr.mgh.harvard.edu wrote:

Are you confusing GI with LGI?

On Dec 22, 2017, at 4:33 PM, Martin Juneja mj70481@gmail.com wrote:

Hi,

I came across several papers e.g. http://www.sciencedirect. com/science/article/pii/S2213158215000856 where gyrification index (GI) is indicated in 'mm'.

By definition GI is the ratio of two quantities: inner contour/outer contour (http://en.citizendium.org/wiki/Gyrification), therefore, shouldn't GI be 'unitless' then?

I am not sure which way is this correct?

Thanks.

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