01-05-2012 | Magnetic Resonance
Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging of multiple myeloma: initial clinical efficiency results
Published in: European Radiology | Issue 5/2012
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Objectives
To evaluate the effectiveness of the iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) MRI to quantify tumour infiltration into the lumbar vertebrae in myeloma patients without visible focal lesions.
Methods
The lumbar spine was examined with 3 T MRI in 24 patients with multiple myeloma and in 26 controls. The fat-signal fraction was calculated as the mean value from three vertebral bodies. A post hoc test was used to compare the fat-signal fraction in controls and patients with monoclonal gammopathy of undetermined significance (MGUS), asymptomatic myeloma or symptomatic myeloma. Differences were considered significant at P < 0.05. The fat-signal fraction and β2-microglobulin-to-albumin ratio were entered into the discriminant analysis.
Results
Fat-signal fractions were significantly lower in patients with symptomatic myelomas (43.9 ±19.7%, P < 0.01) than in the other three groups. Discriminant analysis showed that 22 of the 24 patients (92%) were correctly classified into symptomatic or non-symptomatic myeloma groups.
Conclusions
Fat quantification using the IDEAL sequence in MRI was significantly different when comparing patients with symptomatic myeloma and those with asymptomatic myeloma. The fat-signal fraction and β2-microglobulin-to-albumin ratio facilitated discrimination of symptomatic myeloma from non-symptomatic myeloma in patients without focal bone lesions.
Key Points
• A new magnetic resonance technique (IDEAL) offers new insights in multiple myeloma.
• Fat-signal fractions were lower in patients with symptomatic myelomas than in those with asymptomatic myelomas.
• The β2-microglobulin-to-albumin ratio also aided discrimination of symptomatic myeloma.
• The fat-signal fraction may provide information about the myeloma cell mass.