[MINC-users] dcm2mnc & frames times

[Jérôme Redouté]

Hello all,

we have noticed that frames times for dynamic PET volumes from our 
Siemens PET scanner are strangely extracted during dcm2mnc conversion:

here is an example of the time variable given by mincinfo:

> -0.021253439619000346478
> 29.978746560380997721
> 59.978746560380997721
> 89.97874656037998875
> 119.91498685595000495
> 179.91498685594999074
> 239.91498685594996232
> 299.91498685594996232
> 359.91498685594996232
> 419.91498685594996232
> 479.23494067776994143
> 659.23494067776994143
> 839.23494067776994143
> 1019.2349406777999548
> 1199.2349406778000684
> 1379.2349406778000684
> 1559.2349406778000684
> 1739.2349406778000684
> 1919.2349406778000684
> 2097.8751627063998058
> 2397.8751627063998058
> 2697.8751627063998058
> 2997.8751627063998058
> 3297.8751627063998058
> 3597.8751627063998058
> 3897.8751627063998058
> 4197.8751627064002605
> 4497.8751627064002605
> 4797.8751627064002605
> 5097.8751627064002605

of course we expect integers!

we can try to correct this in our processing scripts, but you can notice 
that for the 10th frame, removing the decimal part leads to an error of 
1 sec ...

> 8th: 299.91498685594996232 => 300 to 360 (60 sec duration)
> 9th: 359.91498685594996232 => 360 to 420
> 10th: 419.91498685594996232 => 420 to *480*
> 11th: 479.23494067776994143 => *479 to 549*

Any ideas?

I can provide a dataset for testing if you need

Thanks

Jerome


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Jérôme Redouté
Ph.D. - Ingénieur de Recherche - Université Claude Bernard - Lyon1
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