[Rtk-users] Angular weighting in gated FDK

[MORY, CYRIL]

Hi RTK users,

I'm working on ECG-gated FDK reconstruction, and I'd like to obtain realistic absorption coefficients, because my gated FDK images have to compared to other reconstruction results which do have realistic values. In FDK, projections are weighted by their angular gaps. I have replaced that by a weighting by 1, because some angular gaps are huge in ECG-gated projection data, and there is no reason why a single projection should be weighed ten times as much as the others. But 1 obviously isn't the right value (with a 20%-wide gating window, I'm getting values about ten times too high). I'm experimenting with smarter choices, like the minimum of the angular gaps (this time it's 10 times too low), and I'll keep experimenting until I find something satisfying.

Does anyone know if there is a standard way of weighting the projections in ECG-gated FDK ? I've made a quick search (maybe too quick), but couldn't find anything on this topic.

Regards,
==========================================
Cyril Mory
PhD student at Philips Medisys and CREATIS

Groupement Hospitalier Est
Hôpital Cardiologique Louis Pradel
Laboratoire CREATIS - Bât. B13
CNRS UMR5220, INSERM U1044, INSA-Lyon, Univ. Lyon 1
28, Avenue du Doyen LEPINE
69677 Bron cedex FRANCE

Office : +33 4 72 35 74 12
Cell : +33 6 69 46 73 79


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