Biomedical Engineering Reference
In-Depth Information
trend. of. increasing. percentage. improvement. as. a. function. of. imaging. depth. similar. to. the. other. two.
tissue.cases..Since.the.scattering.coeicient.in.the.brain.is.much.less.than.that.of.muscles,.the.achievable.
imaging.depth.is.deeper.with.equivalent.excitation.power..However,.the.improvement.at.the.maximum.
achievable. depth. with. and. without. AO. compensation. tissues. was. similar. in. all. cases,. ranging. up. to.
about.twofold.in.terms.of.the.maximum.signal.strength..In.a.previous.report,.luorescently.labeled.blood.
plasma.in.wild-type.zebra.ish.was.imaged.[8]..he.aberrations.introduced.by.the.specimens.were.mainly.
astigmatism.254 nm.at.200.μm.imaging.depth,.and.the.luorescence.signal.at.the.center.of.a.blood..vessel.
was. improved. almost. twofold. by. wavefront. correction. with. the. coherence-gated. wavefront. .sensing.
method.. In. our. measurement,. the. main. aberration. was. also. astigmatism. 125 nm. at. 150.μm. imaging.
depth,.and.the..signal.improvement.was.about.the.same,.which.was.comparable.with.the..previous.result.
35
30
25
20
15
10
5
0
20
μ
m
20
μ
m
FIGuRE 16.12
(
See color insert.
). Mouse-brain. images. at. 50. μm. depth. without. and. with. AO. compensation,.
respectively.
160
60000
60000
140
40000
40000
120
20000
20000
100
0
0
80
60
40
400
300
200
100
0
800
600
400
200
0
20
0
50
100
Depth (
μ
m)
150
(a)
(b)
(c)
FIGuRE 16.13
Signal.improvement.ater.AO.compensation..(a,.b).Histograms.for.the.number.of.pixels.accord-
ing.to.their.intensity;.the.
x-
axis.represents.intensity.of.the.pixels,.and.the.
y-
axis.represents.the.number.of.pixels.in.
the.intensity.range..he.let-placed.columns.show.the.number.of.pixels.before.compensation,.and.the.right-placed.
columns.show.the.result.ater.compensation..Each.histogram.was.normalized.to.itself..he.distribution.at.(a).50.μm.
and.(b).150.μm.imaging.depth..he.bottom.igures.of.panels.a.and.b.are.detailed.distributions.in.the.selected.range..
(c).Percentage.improvement.according.to.the.imaging.depth..he.solid.line.with.triangles.shows.the.improvement.
with. background. rejection. (only. the. luorescent. area. was. calculated),. and. the. solid. line. with. squares. shows. the.
improvement.only.with.90-100%.intensity.pixels.
