Haematologica 2003 - Supplements

191
Volume localized in vivo proton magnetic resonance
spectroscopy (MRS) of the spine in multiple myeloma:
variation of fat-water ratio in patients receiving
chemotherapy.
Oriol A, Capellades Jº, Valverde D*, Cabañas M*, Ribera
JM, Arús C*.
Hematology Service, Hospital Universitari Germans Trias i
Pujol,ºInstitut de Diagnòstic per la Imatge, Hospital Universitari
Germans Trias i Pujol, and *Biochemistry and Molecular Biology
Department, Faculty of Sciences, Universitat Autònoma de
Barcelona.
Introduction. Magnetic resonance imaging (MRI) has become the
method of choice over other imaging modalities in the
noninvasive evaluaton of bone marrow disease. By sampling a
large volume of bone marrow, it provides information that
complements bone marrow aspiration or biopsy in the diagnosis
and staging of multiple myeloma (MM). In the post-treatment
evaluation of patients with MM, bone marrow MRI may provide
important information but assessment of the degree of response is
highly subjective. Proton nuclear magnetic resonance
spectroscopy (1H MRS) may be able to measure the ratio of
water to lipid proton resonance signal intensities and thus reflect
the relative percentages of cellular and fatty bone marrow within
a defined three-dimensional volume (voxel). These measurements
could be used to quantify the degree of cytoreduction in MM
patients.
Patients and methods. Twelve subjects (six male, median age 76
years, range 57-82) with a newly diagnosed multiple myeloma
underwent MRI and 1H MRS of the fifth lumbar vertebral body.
Six of them could be re-evaluated after completing six cycles of
chemotherapy (2 of them had progressed, 1 presented a partial
response and 3 had achieved a complete response). All measures
were performed with a 1.5-T system (Gyroscan Intera, Philips).
Voxel imaging parameters included repetition time of 5000 msec
and echo time of 40 msec, voxel size of 2x2x2 cm, 32
measurements were acquired with a spectral bandwidth of 1000
Hz. Spectra at diagnosis and after-treatment of the six patients
who completed the study were compared for differences in peak
intensities, peak areas and lipid to water ratios (LWR). Agematched
individuals submitted to MRI for reasons not related to
bone or bone marrow pathology were used as controls. A
McNemar signs test was used to assess statistical significances of
the spectral changes.
Results. The initial water peak intensity was initially high in all
patients when compared to age-matched reference values and it
significantly decreased after treatment (p=0.028). A decrease of
the water peak intensity < 50% after treatment was associated to
progression (2 cases) or partial response (1 case). Measurements
of the water resonance as peak area correlated well with intensity
measurements (r=0.93, p