Intravoxel incoherent motion diffusion MR and diffusion kurtosis imaging for discriminating atypical bone metastasis from benign bone lesion

Abstract

Objectives: To investigate the feasibility of intravoxel incoherent motion (IVIM) diffusion MR and diffusion kurtosis imaging (DKI) in discriminating atypical bone metastasis from benign bone lesion in patients with tumors. Methods: Patients with bone lesions in lower extremity suspected of metastases were enrolled in this prospective study. IVIM diffusion MR and DKI were performed before biopsy. Apparent diffusion coefficient (ADC), true diffusion (D), perfusion fraction (f) and perfusion-related pseudodiffusion (D*) were generated with IVIM, while mean kurtosis (MK) and mean diffusion (MD) generated with DKI. Two radiologists blinded to pathology results separately measured these parameters for each lesion through drawing region of interest. Intraclass correlation coefficient was used to determine the inter-reader viability in measurement. The patients with pathology-confirmed metastasis or benign lesion were analyzed. The Mann–Whitney test was used to compare IVIM and DKI parameters between metastasis group and benign lesion group. Receiver operating characteristic curves were constructed to evaluate the ability of discrimination. Results: Bone lesions from 28 patients (metastasis, n = 15; benign lesion, n = 13; mean age = 55 years; age range, 34~77) were analyzed with IVIM and DKI. Intraclass correlation coefficient was greater than 0.8 for all parameters. ADC, D and MD were significantly lower in metastases versus benign lesions (p <0.05). MK and f value were significantly higher in metastases versus benign lesions (p<0.05). D* was not significantly different between the two groups (p>0.05). Areas under curve for ADC, D, f, MK and MD were 0.935, 0.939, 0.891, 0.840 and 0.844 respectively. Conclusions: IVIM and DKI derived parameters distinguish between atypical bone metastasis and benign bone lesion in selected patients with tumors. Advances in knowledge: Bone metastasis and benign bone lesion differ in water molecular diffusion. Intravoxel incoherent motion derived true diffusion distinguishes between atypical bone metastasis and benign lesion.

Different Attenuation Models of Diffusion‐Weighted MR Imaging for the Differentiation of Benign and Malignant Musculoskeletal Tumors

“…For K vol , we found a statistically significant difference between benign and malignant tumors in the "all tumors" group and in the nonmyxoid and nonchondroid tumor subgroup. Similar to other studies that assessed the use of K value in differentiating benign and malignant tumors, [16][17][18][19] we found higher K vol and K min values in malignant tumors. Unlike ADC vol , D* vol and K vol appear to be potentially useful for differentiating benign and malignant musculoskeletal tumors when performing volumetric measurements.…”

“…The number of studies that assess the value of IVIM and DK in the differentiation of benign and malignant musculoskeletal tumors is fewer than those using the monoexponential diffusion model. [8][9][10][11][12][13][14][15][16][17][18][19] In this study, we found a statistically significant difference in D ivim-min between benign and malignant tumors in the "all tumors" group and in the nonmyxoid and nonchondroid tumor subgroup. The best cut-off value was 0.999 Â 10 À3 mm 2 s À1 for D ivim-min in both tumor groups.…”

“…19 In one study that assessed the accuracy of IVIM and DK parameters in comparison to monoexponential DWI in patients with bone tumors, authors found a comparable diagnostic performance between mean diffusivity and mean kurtosis parameters and ADC values (AUCs of 0.844, 0.84, and 0.935, respectively). 17 The difference in their results might be due to the difference in the ROI measurement technique during which they placed three ROIs in three consecutive slices where the tumor size was the largest. Further studies with a larger series of patients are needed to optimize the measurement method.…”

“…Several studies have assessed the value of DK imaging in the differentiation of benign and malignanttumors and have shown that K values tend to be higher in malignant lesions compared to benign lesions. [16][17][18][19][31][32][33][34] In a prospective study by Ogawa et al that assessed the value of DK and compared DK with the m-DWI technique, a significant difference was found between K values of benign and malignant tumors (0.49 AE 0.17 vs 1.14 AE 0.30, respectively). 19 In our study, we similarly found a significant difference between benign and malignant tumors for K min (0.66 AE 0.25 vs. 0.99 AE 0.4 and 0.71 AE 0.29 vs. 1.13 AE 0.36 for the "all tumors" group and the nonmyxoid and nonchondroid tumor subgroup, respectively).…”

“…4 DK-derived mean diffusivity (D K ) represents the corrected diffusion coefficient according to such non-Gaussian behavior, and the mean kurtosis (K) value quantifies the deviation of molecular diffusion from the Gaussian distribution. 4 Although a variety of functional imaging techniques, including m-DWI, IVIM and DK, have been used [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in differentiating benign and malignant musculoskeletal tumors, all three techniques have not been studied in the same patient population.…”