Table 1.
MRI sequence protocol.
Table 2.
Patient characteristics, biochemistry, and MRI-derived indices at baseline.
Fig 1.
Boxplot of percentage changes in total diffusion volume (tDV) calculated from whole-body DWI and fat fraction (FF) of lumbar bone marrow by mDixon Quant during two courses of chemotherapy.
At the second examination, tDV is significantly decreased and FF is significantly increased in the CR/VGPR group. The PR/SD/PD group includes patients showing responses to chemotherapy ranging from partial response to progressive disease. *, P < 0.05.
Table 3.
Percentage changes in serological and MRI-derived indices at second MRI.
Table 4.
General linear model examining the influence of clinical indices for predicting achievement of CR/VGPR.
Fig 2.
Receiver operating characteristics (ROC) curve for fat fraction (FF) of lumbar bone marrow by mDixon Quant sequence and serum M protein for predicting achievement of CR/VGPR.
Areas under the ROC curve are 0.964 for FF and 0.847 for M protein.
Table 5.
ROC results of parameters for predicting patients achieving CR/VGPR.
Fig 3.
Whole-body MRI with a diffuse-dominant pattern.
Sagittal T1-weighted images (T1WI, a), whole-body diffusion-weighted MRI (WB-DWI, b), and fat fraction (FF) map (c) at baseline, and corresponding T1WI (d), WB-DWI (e), and FF map (f) at 2 cycles of chemotherapy for a 60-year-old woman with symptomatic myeloma who relapsed after autologous stem cell transplantation. MRI shows diffuse low signal in the spine on T1WI (a) and diffuse high signal in the axial skeleton on WB-DWI (b) at baseline. After 2 cycles of chemotherapy with carfilzomib, lenalidomide, and dexamethasone, total diffusion volume (tDV) has significantly decreased (from 201 ml to 21 ml) and the FF (f) in the lumbar bone marrow has significantly increased (from 2% to 25%), indicating a decrease in the tumor mass.
Fig 4.
Whole-body MRI with a combined diffuse and focal pattern.
Sagittal T1-weighted images (T1WI, a), whole-body diffusion-weighted MRI (WB-DWI, b), and fat fraction (FF) map (c) at baseline, and corresponding T1WI (d), WB-DWI (e), and FF map (f) at 2 cycles of chemotherapy for a 64-year-old woman with symptomatic myeloma who relapsed after chemotherapy with carfilzomib, lenalidomide, and dexamethasone. MRI shows focal bone lesions and heterogeneous low signal in the spinal bone marrow on T1WI (a). After 2 cycles of chemotherapy with pomalidomide and dexamethasone, total diffusion volume has decreased (from 263 ml to 176 ml), but FF in lumbar bone marrow has not shown significant change (from 15% to 16%).
Fig 5.
Whole-body MRI with a focal-dominant pattern.
Sagittal T1-weighted images (T1WI, a), whole-body diffusion-weighted MRI (WB-DWI, b), and fat fraction (FF) map (c) at baseline, and corresponding T1WI (d), WB-DWI (e), and FF map (f) at 2 cycles of chemotherapy for a 70-year-old woman with symptomatic myeloma. MRI shows numerous focal bone lesions throughout the body at baseline. After 2 cycles of chemotherapy with bortezomib and dexamethasone, total diffusion volume does not show any significant change (from 47 ml to 49 ml), but FF in the lumbar bone marrow has decreased by 30% (from 56% to 40%), indicating an increase in diffuse infiltration into bone marrow by myeloma.