Fig 1.
Semi-automated segmentation of myeloma lesions and measurement of fat fraction on MR images.
(A) Coronal maximum intensity projection image acquired by diffusion-weighted imaging with a computed b-value of 1000 s/mm2. For estimation of whole-body volumetric tumor burden by measurement of apparent diffusion coefficient (ADC), voxels showing an ADC between 0.55 ×10−3 and 2.0 ×10−3 mm2/s are extracted (indicated in orange) as an estimate of total diffusion volume, as a surrogate marker for tumor burden. (B) Coronal fat fraction map obtained by modified Dixon Quant sequence. The region of interest (white rectangle) for measuring fat fraction is placed on the L3 vertebral body on a midcoronal image. The region of interest cannot be placed from L1 to L3 on a single image because the mid-coronal level of each vertebral body is different due to lumbar lordosis.
Table 1.
Patient characteristics and biochemistry results.
Table 2.
Comparison of MRI-derived indices according to their response to mobilization.
Table 3.
Predictive factors significantly associated with relatively poor mobilization by multivariate analysis.
Fig 2.
Receiver-operating characteristic (ROC) curve for median apparent diffusion coefficient.
The area under the ROC curve is 0.784.
Fig 3.
Representative whole-body diffusion-weighted imaging (DWI) for the patient classifications of mobilizer and relatively poor mobilizer.
Left image, mobilizer: Whole-body DWI of a 47-year-old man with symptomatic myeloma who had an adequate number of collected CD34+ cells (4.4×106 CD34+ cells/kg). Median ADC of the total diffusion volume was 0.78×10−3 mm2/s. Right image, relatively poor mobilizer: Whole-body DWI of a 59-year-old woman with symptomatic myeloma who had an inadequate number of collected CD34+ cells (3.8×106 CD34+ cells/kg). Median ADC of the total diffusion volume was 1.53×10−3 mm2/s.