hepanin els.
pending
There
the
were
no
attainment
cedune. No pnedisposing ered; the patient remains Widlus
et al have
or to treatment bolysis,
of therapeutic
complications
during
cause of the symptoms symptom-free.
shown
that
the
is an important
but
they
infer
wanfanin
that
the
was
pro-
of symptoms should
throm-
be
for
DM,
upper
Venbrux
AC,
extremity
Benenati
arterial
JF, et al.
occlusions.
ms)
20
consid-
ered even with a long-standing history. We entirely agree with this suggestion and confirm that excellent results can be obtained in the patient with a delayed presentation. Reference 1. Widlus
423
(Ti
pni-
for complete
treatment
S low Ti pIxels 30
discov26
duration
indicator such
1ev-
or following
Fibrinolytic
Radiology
\
\
10
:
therapy
1990;
16
175:393-
399.
20
30
after
days U Marrow Transplantation
Repopulation
After
Bone
Marrow
Alterations in lumbar
From: Stephen R. Smith, MRCP, Neil T. Edwards, FRCP Magnetic Resonance Research
P0 Box 147, Liverpool
Roberts,
PhD,
Centre,
and
Richard
University
L69 3BX, United
H.
April
1990
interesting
and
issue
of Radiology,
important
data
nance (MR) characteristics plantation. We have also niques dergoing for
to study lumbar autobogous
refractory
bowed
or
up
nine
Stevens concerning
this
relapsed
bone marrow transplantation
Hodgkin
patients
et al (1) present the magnetic reso-
of vertebral marrow after transused quantitative MR imaging tech-
vertebral bone marrow serially
disease to the
time
in
patients (ABMT)
(2) and
have
of recovery
un-
fobof sta-
ble, normal peripheral blood counts. In our initial study, a decrease in mean lumbar vertebral marrow Ti relaxation time was seen after a chemotherapy-based conditioning regimen. Ti then recovered as hematopoietic engnaftment occurred, sometimes
to bevels
higher
than
those
before
transplantation.
Changes in Tl, measured with use of region of interest (ROI) cursors, mirrored the recovery of peripheral blood neutrophib and platelet counts and presumably reflect alterations in manrow cellularity (2). However, the zone pattern reported by Stevens et al was not observed in any of our patients with use of imaging protocols (repetition time msec/echo time msec, 500/25,
the
relaxation
time
measurements
be viewed with caution due to the use of a method and multisection imaging techrelaxation time measurements made with
use of ROI cursors in heterogeneous
are associated with tissues such as bone
we
use
problems, marrow
multiple
point,
pixel-by-pixel
image
analysis
techniques
with
particularly (3). For these Ti
mapping
in
to monitor
tionship
protocol
provides
reproducible
relaxation
time
data
(4).
in color
of thresholded
means ban
of ABMT. vertebrae
In
these
studies
are
the
The
transplantation
to factors ease prior therapy tioning transplant
and radiation regimen used, was placed,
178
Number
#{149}
2
for
body
can
of area of marrow in a treatment by
all
zones
in
Ti
pixels
consistent
of the
the
of marrow by
the
bum-
zonal
differences
pattern
relaxation
image
analysis
of measuring heterogeneous be monitored
in
regeneration
different
of results
made. Pixel-by-pixel with
reasons
these
after
workers
may
marrow be
related
and the state of previous
of dischemo-
received, the particular condian autobogous or allogeneic presence of graft-versus-host
of all these
comparisons
details
from
time
techniques
is necessary
different
studies are
if mean-
centers
used
are
to be
in conjunction
superior
to ROI
methods
relaxation time data. They enable potentially changes in tissues or tumors after treatment quantitatively.
to
References
I.
Volume
images.
vertebral
in support
therapy whether and the
A knowledge
ingfub
erwood
for the below
low
such as the underlying disease to transplantation, the intensity
JPR,
is used as a Ti threshold distribution of Ti pixels
in
evidence
observed
Jenkins
value spatial
the
to therapy, increase
pattern
3.
This the
an
possible
MR
Smith SR. Williams magnetic resonance
subjects. data, and
within
response
showed
2.
control patient
gray-scale
of engraftment proposed by Stevens et ab (ie, persistent bow Ti pixels in the central area of the vertebral bodies corresponding to zone 4, and a peripheral area of high Ti pixels corresponding to zone 1).
gonithms (Struers
isolate only those pixels that refer to the lumbar vertebral bone marrow. The Ti data are displayed in histogram form, and the Ti value of the 5% probability limit is calculated (423 msec) from the pooled Ti histogram data of 18 age-matched
original
with myeboabbative chemotherapy, followed by a decrease in the number of bow Ti pixels as engraftment occurred. Twelve studies have been performed 40-90 days after ABMT; none of
1.
analysis system then used to
pixels
showed
The boundaries of the lumbar vertebral bodies are identified semiautomatically (less than 5% operator interaction) from proton density MR images with use of line detection alavailable on a Context Vision image Vision AB, Sweden). These masks are
on
then be quantified objectively. The Figure shows the alterations in percentage the bow Ti pixels in zones 1-4 of the vertebral patient with Hodgkin disease before and after
disease.
changes in the lumbar vertebral marrow after ABMT. Ti maps are computed with use of a SUN 3/160 workstation (Sun Microsystems, Mountain View, Cabif) from six spin-echo images acquired with repetition times varying from 2,400 to 250 msec of a single midline sagittal section of the lumbar vertebrae. A 10-mm section thickness is used, and pixel nesolution is 1.88 X 1.88 mm. All MR imaging data were acquired with a 1.5-T Signa system (GE Medical Systems, Milwaukee). The
is displayed
results?
they present must two-point data fit niques. In addition,
conjunction
limit
What
et ab state,
423 msec) ABMT for cortex of zone 4, X zone
The area of these thresholded pixels is then calculated. In particular, with use of morphologic image analysis techniques, the masks are successively shrunk in bands of 5 pixels deep, enabling four separate zones of marrow to be isolated. These range from a peripheral area (zone 1) adjacent to the cortex of the vertebral body to a central area (zone 4). The spatial nela-
250/25).
As Stevens
reasons,
in percentage of area of low Ti pixels (Ti vertebral marrow of patient who underwent refractory Hodgkin disease. Zone i was adjacent to the the vertebral body, moving in through zones 2 and 3 to which occupied the central area of the vertebral bodies. 1, = zone 2, * zone 3, 0 zone 4.
of Liverpool
Kingdom
Editor:
In the
treatment
Stevens 5K, Moore ter transplantation: diology
1990;
plantation
4.
SC, Amylon MR imaging
Repopulation pathologic
of marrow correlation.
afRa-
175:213-218.
CE, Edwards RHT, Davies JM. Quantitative imaging in autologous bone marrow transHodgkin’s disease. Br J Cancer 1989; 60:961-965.
for
Stehling
M,
Quantitative
bodies:
a T1 and
Smith
SR. Williams characterization
ogy
172:805-810.
Sivewright
C,
magnetic
T2 study.
disorders:
1989;
MD. with
Magn
CE, Davies with
Hickey
resonance Reson
JM,
Imaging
Edwards
quantitative
DS,
imaging 1989;
RHT. MR
Hillier
VF,
Ish-
of vertebral 7:17-23.
Bone imaging.
Radiology
marrow Radiol-
581
#{149}