Dear Chris and Mike:
Thank you for your responses and I haven't read these articles and
abstracts mentioned in your E-mail yet. I'm still using SPM 96 version.
I have several questions and statement here related to your E-mail.
1). Our NM physicians use the 7% based on ' plenty of NM literature '
that the range of asymmetry in SPEC scans of normal population is from
5% to 10%. They call 7-9 % in borderline and > 9 % as abnormal with
traditional RIO method; I did some phantom studies using Hoffman Brain
Phantom and found there is 5% asymmetry with optimum setting of
acquisition; CERETEC has a 5-10% asymmetry on normal scan according to
Amersham (ECD?). It's almost impossible to get a actual normal pediatric
subject scan and they all come in with some kind of diagnosis. So I
selected these less than 7 % asymmetry as a control group not a normal
baseline.
2). After I read Stamatakis's articles, I may understand more why they
want to use a custom SPECT template instead of a supplied PET template.
Do you think that 'no major differences between a custom SPECT and
supplied PET template for normalization results' can be extended to
pediatric patient (assuming supplied PET made from adult)?
3). When I learnt the SPM from a local spmer, I have been instructed
that I had to do at least Coregister and reslice and Spatial
Normalization (Smooth as an option) on an object image to create a
snr---.img file for Statistics. I have been suggested to use supplied
PET as template then. But I have a impression from your E-mails that the
Coregister step might not be necessary in the process (?).
With regards
Bing Fang, B.M, M.S.
Clinical Instructor
Radiologic Physicist
Dep. of Radiology
Uni. of Texas Houston Medical School
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