Ga-Eun Park MD, Presenter: Nothing to Disclose

Won-Hee Jee MD, Abstract Co-Author: Nothing to Disclose

So-Yeon Lee MD, Abstract Co-Author: Nothing to Disclose

Jin-Kyeong Sung MD, Abstract Co-Author: Nothing to Disclose

Robert Grimm, Abstract Co-Author: Employee, Siemens AG

Kee-Yong Ha, Abstract Co-Author: Nothing to Disclose

Joon-Yong Jung MD, Abstract Co-Author: Nothing to Disclose

: To retrospectively determine the value of adding axial diffusion-weighted imaging (DWI) to standard magnetic resonance imaging (MRI) to differentiate between skeletal multiple myeloma from metastases at 3.0 T, using mean ADC (ADCmean), minimum ADC (ADCmin), and volume ADC (ADCvolume).

The institutional review board approved this HIPAA-compliant study, and informed consent was waived. The authors retrospectively analyzed 3.0 T MRI including DWI with high b value in 43 patients with treatment-naïve bone metastases or multiple myeloma. Two radiologists independently interpreted MR images for the presence of multiple myeloma by using standard MRI alone and standard MRI and axial DWI combined. ADCmean, ADCmin, and ADCvolume from ADC histograms on volume of interests were measured by two independent reviewers. Mann-Whitney U test was performed. Area under the Receiver operating characteristic curve (AUC) was obtained for the differentiation of multiple myeloma from metastases. 

There were 25 patients with bone metastases and 18 patients with multiple myeloma: 38 metastases and 36 multiple myeloma lesions. ADCmean, ADCmin and ADCvolume of multiple myeloma were significantly lower than those of metastases; 752 µm2/sec (interquartile range, 619, 849), 704 (587, 773) and 747 (636, 860) for multiple myeloma; 1081 µm2/sec (813, 1248), 835 (709, 1089) and 933 (718, 1322) for metastases (P < .05).With standard MRI alone, the sensitivity, specificity and accuracy were 61%, 88%, and 77%, respectively for reader 1, and 61%, 96%, and 81% for reader 2. With standard MRI and DWI combined, the sensitivity, specificity and accuracy were 100%, 92%, and 95% for reader 1, and 94%, 96%, and 95% for reader 2. Diagnostic performance of both readers improved significantly after additional review of DWI: AUCs improved from 0.762 to 0.953 and from 0.706 to 0.950 (P <.005) for two readers. AUC of ADCvolume (0.668) was significantly lower than those of ADCmean and ADCmin (P < .005). Interobserver agreements were fair to good for ADCmean (ICC = 0.741) and excellent for ADCmin (ICC = 0.821).

The addition of axial DWI to a standard MRI improved the diagnostic accuracy in the differentiation of skeletal multiple myeloma from metastases, particularly using ADCmean and ADCmin.

DWI should be added to standard MRI in clinical routine to help differentiate between skeletal multiple myeloma and metastases.  

Park, G, Jee, W, Lee, S, Sung, J, Grimm, R, Ha, K, Jung, J, Differentiation of Skeletal Multiple Myeloma and Metastases Using Addititive Axial Diffusion-weighted MR Imaging to Standard MR Imaging: Use of ADCmean, ADCminimum, and ADCvolume at 3.0 T.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003587.html