cedune. No pnedisposing ered; the patient remains Widlus
et al have
or to treatment bolysis,
cause of the symptoms symptom-free.
is an important
of symptoms should
JF, et al.
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
S low Ti pIxels 30
days U Marrow Transplantation
Alterations in lumbar
From: Stephen R. Smith, MRCP, Neil T. Edwards, FRCP Magnetic Resonance Research
P0 Box 147, Liverpool
L69 3BX, United
nance (MR) characteristics plantation. We have also niques dergoing for
to study lumbar autobogous
bone marrow transplantation
et al (1) present the magnetic reso-
of vertebral marrow after transused quantitative MR imaging tech-
vertebral bone marrow serially
disease to the
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
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,
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
particularly (3). For these Ti
of ABMT. vertebrae
to factors ease prior therapy tioning transplant
and radiation regimen used, was placed,
of area of marrow in a treatment by
of marrow by
of measuring heterogeneous be monitored
made. Pixel-by-pixel with
and the state of previous
received, the particular condian autobogous or allogeneic presence of graft-versus-host
of all these
relaxation time data. They enable potentially changes in tissues or tumors after treatment quantitatively.
therapy whether and the
for the below
such as the underlying disease to transplantation, the intensity
is used as a Ti threshold distribution of Ti pixels
to therapy, increase
Smith SR. Williams magnetic resonance
subjects. data, and
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).
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
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
analysis system then used to
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
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
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
they present must two-point data fit niques. In addition,
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-
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.
Stevens 5K, Moore ter transplantation: diology
SC, Amylon MR imaging
of marrow correlation.
CE, Edwards RHT, Davies JM. Quantitative imaging in autologous bone marrow transHodgkin’s disease. Br J Cancer 1989; 60:961-965.
a T1 and
SR. Williams characterization
CE, Davies with
of vertebral 7:17-23.