Question Posted 05/07/15:
I have recently downloaded all the "Early AV45" scans as NiFTI-4D, and I was wondering if the frame duration is consistent across the sites/scanners. I downloaded an exemplar in ECAT format, and I see that Frames 1-4 are 15s, Frames 5-8 are 30s, Frames 9-11 are 1min, frames 12-14 are 2min, and Frames 15-16 are 4min. I haven't been able to locate the early add-on protocol anywhere on this site (or elsewhere), and I'm hoping I don't have to re-download everything in the archived format and re-convert on my own after I survet frame durations. Thanks in advance for any help.
Response posted 05/07/15 by Bob Koeppe:
Yes, all the early AV45 scans were acquired with the same 16 frame, 20-min protocol.

If I am remembering correctly, there may have been one "early" scan that didn't have all 16 frames. If you find one that is missing a frame, the frames that are there, have the same durations