Comparison of monoexponential and biexponential models of diffusion-weighted imaging in differential diagnosis between benign and malignant lesions of primary bone tumors
10.3781/j.issn.1000-7431.2014.02.011
- Author:
Xiao-Ying SHI
1
Author Information
1. Department of Magnetic Resonance Imaging
- Publication Type:Journal Article
- Keywords:
Biexponential model;
Bone neoplasms;
Diffusion-weighted imaging;
Monoexponential model
- From:
Tumor
2014;34(2):163-168
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To compare the value of monoexponential model with single b-factor and biexponential model with extended b-factor range (based on the theory of intravoxel incoherent motion) of diffusion-weighted imaging (DWI) in differential diagnosis of benign and malignant lesions of primary bone tumors. Methods: A total of 29 patients with primary bone tumors underwent DWI based on single b-factor (b values of 0 and 800 s/mm2) and multi-b-factor (b values of 0, 30, 50, 100, 150, 200, 300, 400, 500, 600, 700 and 800 s/mm 2). The subjects were divided into 2 groups according to the pathological results. Benign lesions were found in 13 cases (benign group), while malignant lesions were 16 (maglinant group). The contralateral normal bone marrow of the same patient was used as a control (contral group). Paired comparison of apparent diffusion coefficient (ADC), ADCslow, ADC fast and ffast values among the 3 groups were separately performed. The best thresholds of ADC, ADCslow, ADCfast and ffast were calculated by the receiver operating characteristic (ROC) curve. The diagnostic efficiencies of parameters in the monoexponential model and the biexponential model were compared. Results: The ADC values were (1.97 ± 0.52) × 10-3 mm2/s and (1.28 ± 0.39) × 10-3 mm2/s in the benign group and the malignant group, respectively; there was a significant difference between the benign group and the malignant group (P < 0.05). The ADCslow value of the benign group was also higher than that of the malignant group [(1.82 ± 0.63) × 10-3 mm2/s vs (0.75 ± 0.34) × 10-3 mm2/s, P < 0.05]. There were no significant differences in ADCfast and ffast values among the benign group, malignant group and the control group (P > 0.05). The areas under the ROC curves of ADC, ADCslow, ADCfast and f fast were 0.85, 0.92, 0.69 and 0.44, respectively. For distinguishing the benign and malignant bone tumors, the specificities of ADC, ADC slow, ADCfast and ffast were 87.5%, 93.7%, 57.1% and 37.5%, respectively, and the sensitivities were 76.9%, 84.6%, 46.2% and 84.6%, respectively. Conclusion: The ADC value of monoexponential model and the ADCslow value of biexponential model can provide a certain value for differential diagnosis between benign and malignant lesions of primary bone tumors. The diagnostic efficiency of ADCslow is the best. Copyright © 2014 by TUMOR.
