Hello,

 

I had the problem already with FS 7.2.0, but since it also occurs in FS 8.1.0, which I currently have installed on UBUNTU 20.24, an answer would be helpful. I am fully aware that FS and Synthseg do not provide exactly the same results when calculating the volumes for the same T1 scan with FS and Synthseg. E.g when I calculate a T1 3D 1mm ISO scan and a FLAIR 3D 2mm ISO scan of the same person both with Synthseg, I also fully understand that the results will not be exactly the same here either. However, what I do not understand is that the results for sub-volumes sometimes deviate by a factor of 1000? I have attached a small table below: row 1 Synthseg T1 scan, row 2 Synthseg FLAIR scan, row 3 FS T1 scan same subject. E.g. for "left lateral ventricle," the Synthseg FLAIR and FS results are about the same, but the Synthseg T1 does not match by a factor of 1000. For "left inferior lateral ventricle," the Synthseg FLAIR result is too large. Where do these deviations come from? Is it a unit problem??? I do not understand what is behind it. These deviations occur in all individuals in this manner.

 

Thank you for your help,

       Jürgen

 

subject	total intracranial	left cerebral white matter	left cerebral cortex	left lateral ventricle	left inferior lateral ventricle	left cerebellum white matter	left cerebellum cortex	left thalamus	left caudate	left putamen	left pallidum	3rd ventricle	4th ventricle	brain-stem	left hippocampus	left amygdala	csf	left accumbens area
Syn= 02_t1_5_13	1581149.5	234530.16	279514.53	28584312	515.05	15703237	62220.02	5994828	3766241	4605884	1485176	1864659	2365228	23305277	3743831	1692543	258776.8	679.45
Syn= 02_flair_5_13	1540067.8	237580.17	278995.16	26533.9	462551	14112386	64456.68	6460912	3999.81	4585682	1717103	1535.82	1356496	26397467	3787048	1596163	211639.08	720396
fs= 02_t1.5.3	1558777.000000	212518.500000	248086.368363	30058.0	1061.2	16326.6	57684.7	5877.0	3879.4	4342.9	1751.2	2113.8	2982.3	20526.8	4015.2	1763.8	374287.9	539.0
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