FIGURE 1.
An example of bone marrow (BM) segmentation in multiple myeloma (MM) patient. An oval regions of interests (ROIs) of 100 mm2 was drawn at the central slice of sagittal vertebral bodies L1−L5 in different virtual calcium subtraction (VNCa) images and the corresponding location was manually displayed on the axial apparent diffusion coefficient (ADC) map. (A) calcium-suppressed (CaSupp) index 25, (B) CaSupp index 55, (C) CaSupp index 85, (D) CaSupp index95, (E) magnification of (C), (F) ADC map.
FIGURE 2.
Flow chart of patients’ selection.
DLCT = low-dose dual-layer spectral CT; MM = multiple myeloma
TABLE 1.
Patient characteristics
| Characteristics | n |
|---|---|
| Age* | 57.9 ± 8.1 |
| Sex# | |
| Males | 26 (55.3%) |
| Females | 21 (44.7%) |
| Myeloma subtypes# | |
| IgG | 32 (68.1%) |
| IgA | 10 (21.3%) |
| Light chain | 5 (10.6%) |
| Plasma cell infiltration ratio obtained from the wing of ilium* | 0.54 ± 0.30 |
| Kappa/lambda SFLC ratio# | |
| High (< 0.01 or > 100) | 27 (57.4%) |
| Low (0.01−100) | 20 (42.6%) |
| Cytogenetic status# | |
| HRC | 26 (55.3%) |
| SRC | 21 (44.7%) |
FIGURE 3.
Heat map of Pearson’s correlation r and p value between CT numbers (combined different calcium-suppressed [CaSupp] indices with measured locations) and apparent diffusion coefficient (ADC) values.
TABLE 2.
Means and standard deviations of MRI apparent diffusion coefficient (ADC) and CT numbers in virtual calcium subtraction (VNCa) images for all measured locations
| L1 | L2 | L3 | L4 | L5 | Averaged L1−L5 | |
|---|---|---|---|---|---|---|
| ADC | 554.12±177.42 | 520.02±171.74 | 546.19±179.75 | 523.20±175.14 | 524.3±173.17 | 536.30±163.93 |
| CaSupp 25 | −236.58±77.07 | −227.60±73.00 | −217.83±83.35 | −225.40±82.36 | −244.67±79.27 | −221.19±78.89 |
| CaSupp 35 | −138.15±46.58 | −131.15±43.86 | −127.11±51.4 | −133.38±49.30 | −143.10±48.23 | −128.84±47.37 |
| CaSupp 45 | −82.04±30.19 | −77.33±28.86 | −75.38±34.45 | −81.01±31.32 | −85.24±31.31 | −76.42±30.10 |
| CaSupp 55 | −45.12±20.87 | −41.925±20.70 | −41.32±24.80 | −46.57±20.95 | −47.08±21.44 | −41.92±19.91 |
| CaSupp 65 | −18.50±16.35 | −16.38±17.05 | −16.79±19.89 | −21.71±15.83 | −19.71±16.14 | −17.07±14.58 |
| CaSupp 75 | 2.03±15.39 | 3.29±16.53 | 2.12±18.3 | −2.58±14.9 | 1.42±14.54 | 2.08±13.26 |
| CaSupp 85 | 18.63±16.60 | 19.22±17.75 | 17.45±18.93 | 12.93±16.52 | 18.55±15.37 | 17.61±14.59 |
| CaSupp 95 | 32.46±19.15 | 32.46±20.12 | 30.25±20.75 | 25.98±19.16 | 33.00±17.41 | 30.59±17.20 |
[i] CaSupp = calcium-suppressed index
FIGURE 4.
Bivariate correlation between CT number (averaged L1−L5 at calcium-suppressed [CaSupp] index 85) and plasma cell infiltration rate (PCIR) confirmed by bone marrow biopsy. The Pearson’s r yields 0.835 with p value < 0.001.
FIGURE 5.
Receiver operating characteristic curves for CT number (averaged L1−L5 at calcium-suppressed [CaSupp] index 85) to predict “high serum-free light chains (SFLC) ratio” (A) and “cytogenetic status” (B).