Quantitative Diffusion-weighted Imaging of the Bone Marrow: An Adjunct Tool for the Diagnosis of a Diffuse MR Imaging Pattern in Patients with Multiple Myeloma

Abstract

Purpose To evaluate the apparent diffusion coefficients (ADCs) of magnetic resonance (MR) imaging patterns in the bone marrow of patients with multiple myeloma (MM) and to determine a threshold ADC that may help distinguish a diffuse from a normal pattern with high accuracy. Materials and Methods This prospective study was approved by the ethics review board, and informed consent was obtained. Ninety-nine patients with newly diagnosed, untreated MM and 16 healthy control subjects underwent spinal MR imaging including diffusion-weighted imaging, and bone marrow ADCs were calculated. Pattern assignment was based on visual assessment of conventional MR images. The Kruskal-Wallis H test, the Mann-Whitney test, and the one-way analysis of variance were used to compare ADCs between patient subsets and control subjects, and a receiver operating characteristic analysis was performed. Results Mean ADCs ± standard deviation in patients with MM for the normal, focal, and diffuse MR imaging patterns were 0.360 × 10 mm/sec ± 0.110, 1.046 × 10 mm/sec ± 0.232, and 0.770 × 10 mm/sec ± 0.135, respectively. There were significant differences in ADCs between diffuse and normal (P < .001), diffuse and focal (P < .001), and focal and normal (P < .001) patterns. Patients with a diffuse pattern had more features of advanced disease, higher international staging system score, increased incidence of high-risk cytogenetics, and higher revised international staging system score. ADCs greater than 0.548 × 10 mm/sec showed 100% sensitivity (26 of 26) and 98% specificity (48 of 49) for the diagnosis of a diffuse (vs normal) MR imaging pattern, whereas an ADC greater than 0.597 × 10 mm/sec showed 96% sensitivity (25 of 26) and 100% specificity (49 of 49). Conclusion ADCs of MR imaging patterns in patients with MM differ significantly. A diffuse MR imaging pattern can be distinguished more objectively from a normal MR imaging pattern by adding quantitative diffusion-weighted imaging to standard MR imaging protocols. RSNA, 2016 Online supplemental material is available for this article.

Applications of PET‐MRI in musculoskeletal disease

“…Incorporation of DWI results in superior lesion conspicuity compared with conventional STIR and contrast‐enhanced MRI, and ADC values can be used with excellent accuracy (90% sensitivity and 93% specificity) to differentiate diseased and normal marrow . Quantitative ADC analysis has shown particular value in determining diffuse involvement; a bone marrow ADC greater than 0.548 × 10 −3 mm 2 /s has been shown to be 100% sensitive and 98% specific for diagnosing a diffuse marrow pattern …”

MRI biomarkers in osseous tumors

“…Variable low ADCs have been reported in osteosarcoma (OS), Ewing sarcoma, plasmacytoma, multiple myeloma (MM), lymphoma, and bone metastases . Among them, small round cell tumors like Ewing sarcoma, plasmacytoma, MM, and lymphoma tend to have somewhat consistently lower values around 0.9 × 10 −3 mm 2 /s, with some overlapping with the range of normal red marrow . In OS, variable ADC can be measured according to histological features (Fig.…”

“…ADC has been used in patients with MM to differentiate the focal type from the diffuse type, which is associated with an advanced disease and worse prognosis . They found higher ADC in the focal type than in the diffuse type (1.05 ± 0.23 vs. 0.77 ± 0.14 × 10 −3 mm 2 /s) of myeloma.…”

“…36 Among them, small round cell tumors like Ewing sarcoma, plasmacytoma, MM, and lymphoma tend to have somewhat consistently lower values around 0.9 × 10 −3 mm 2 /s, with some overlapping with the range of normal red marrow. 29,[34][35][36][37][38][39][40][41][42] In OS, variable ADC can be measured according to histological features 43 (Fig. 5).…”

Diffusion magnetic resonance imaging: A molecular imaging tool caught between hope, hype and the real world of “personalized oncology”

“…DWI is also found to have a diagnostic value in evaluating patients with multiple myeloma. The reported mean ADCs for normal marrow, focal, and diffuse marrow involvement pattern is 0.360 × 10 -3 mm 2 /s ± 0.110, 1.046 × 10 -3 mm 2 /s ± 0.232, and 0.770 × 10 -3 mm 2 /s ± 0.135, respectively[91]. …”