acoustic neuroma scan sequence
------------------------------

These are ANALYZE images, all 256 by 256 pixel, 3mm slice thickness,
25 slices, 1mmx1mm pixel size according to ANALYZE header, but 
the original dicom said that they were .898mmx.898mm.  Some z
normalisation has taken place to ease any rendering and anlysis.

There are 5 sequences:  T1 vol (t1), T1 vol + contrast (t1c), 
proton density (pd), T2 (t2), and inversion recovery (ir).

pd and t2 are perfectly correlated (same acquisition sequence).
pd, ir, and t2 are pretty close (same original position and slice number).
t1 and t1c are pretty close (same identical scan, but much time in
between).
all are closely coregistered, but probably not perfect.  The t1
images were scanned using 50 slices originally, but I tried my best to 
get them lined up.

Therefore, all of them should be reasonably alligned and reasonably
constant in intensity range within each sequence.  


Oh, yeah, the tumour...It's a 3cm one on the left side.  Can't miss
it.  It's between slices 7 and 16.


