By two-echo methods to individual water- and fat MR signals with symmetrical sampling to yield in- and opposed-phase data, identification of water and fat can be ambiguous (water-fat swaps) due to B0 inhomogeneity [48]. examined with 3-T MRI in 11 patients with asymptomatic myeloma and 24 patients with symptomatic myeloma. The fat-signal portion was calculated from your ratio of the signal intensity in the excess fat image divided by the signal intensity of the corresponding ROI in the in-phase IDEAL image. The test was used to compare the asymptomatic and symptomatic groups. ROC curves were constructed to determine the ability of variables to discriminate between symptomatic and asymptomatic myeloma. Results Univariate analysis showed that 2-microglobulin and bone marrow plasma cell percent (BMPC%) were significantly higher and fat-signal portion was significantly lower with symptomatic myeloma than with asymptomatic myeloma. Areas under the curve were 0.847 for 2;-microglobulin, 0.834 for fat-signal fraction, and 0.759 for SC-26196 BMPC%. Conclusion The fat-signal portion as a biomarker for multiple myeloma enables discrimination of symptomatic myeloma from asymptomatic myeloma. The fat-signal portion offers superior sensitivity and specificity to BMPC% of biopsy specimens. Introduction Asymptomatic multiple myeloma is an asymptomatic proliferative disorder of plasma cells with high risk of progression to symptomatic multiple myeloma. This risk is usually estimated at 10% per year during the first 5 years [1C3]. Progression represents the most severe clinical problem of patients with asymptomatic myeloma. Several groups [2, 4, 5] have SC-26196 therefore proposed different score systems to distinguish between patients with slowly and rapidly progressive asymptomatic myeloma. However, these systems require complex or expensive tools such as multiparametric circulation cytometry of bone marrow plasma cells or gear for comparative genomic hybridization, limiting the feasibility of such methods in clinical practice. Considering the high rate of TPT1 progression of asymptomatic myeloma to symptomatic myeloma, several reports have analyzed the value of early treatment. However, none of these studies have exhibited any clear benefit for patients in terms of overall survival when treated in the absence of symptoms [6C9]. At present, in the absence of reliable elements to predict disease progression, the standard of care for asymptomatic myeloma patients remains close follow-up without treatment until myeloma symptoms develop [3]. Regarding the relationship between findings on magnetic resonance imaging (MRI) and the prognosis of multiple myeloma, St?bler et al. [10] assessed the correlation between MR infiltration pattern, biopsy findings, and a clinical staging system. They recognized five infiltration patterns using T1-weighted and opposed gradient-recalled echo images and demonstrated that this infiltration pattern on unenhanced MRI correlated with the Durries/Salmon staging system. They concluded that high-grade plasma cell infiltration with replacement of excess fat cells caused a pronounced decrease in transmission intensity on T1-weighted imaging. Furthermore, they used the opposed-phase gradient-recalled echo sequence on the basis that a shift in the fat-water ratio results in increased transmission intensity, allowing bone-marrow infiltrating processes SC-26196 to be detected using opposed-phase sequences [10]. However, this kind of qualitative approach lacks objectivity. For example, they differentiated MR infiltration patterns by transmission intensity on T1-weighted images and opposed-phase gradient-recalled echo images SC-26196 in correlation to the intervertebral discs, which might have been subjects to degenerative switch. Therefore, this could have had an influence on the result which showed that MR infiltration pattern had correlation to the clinical staging system. Separation of excess fat and water on MR images based on their chemical shift was originally discussed by Dixon in 1984 [11]. SC-26196 The original two-point technique with one in-phase and one opposed-phase image was later extended to multi-point methods [12C14]. Many spin-echo (SE) or fast SE (FSE) methods acquire three echoes shifted symmetrically about the SE, creating time-dependent phase shifts caused by water-fat chemical shift [13,15,16]. This work demonstrates that symmetrically acquired echoes cause artifacts that degrade image quality. The noise overall performance of any water-fat separation method is dependent on the proportion of water and excess fat within a voxel, and the position of echoes relative to the SE. IDEAL combines asymmetrically acquired echoes with an iterative least-squares decomposition algorithm to maximize noise overall performance [17]. In recent years,.