Intravoxel incoherent motion diffusion‐weighted MRI at 3.0 T differentiates malignant breast lesions from benign lesions and breast parenchyma

Abstract

Purpose To study the differentiation of malignant breast lesions from benign lesions and fibroglandular tissue (FGT) using apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) parameters. Materials and Methods This retrospective study included 26 malignant and 14 benign breast lesions in 35 patients who underwent diffusion-weighted MRI at 3.0T and nine b-values (0–1000 s/mm2). ADC and IVIM parameters (perfusion fraction fp, pseudodiffusion coefficient Dp, and true diffusion coefficient Dd) were determined in lesions and FGT. For comparison, IVIM was also measured in 16 high-risk normal patients. A predictive model was constructed using linear discriminant analysis. Lesion discrimination based on ADC and IVIM parameters was assessed using receiver operating characteristic (ROC) and area under the ROC curve (AUC). Results In FGT of normal subjects, fp was 1.1 ± 1.1%. In malignant lesions, fp (6.4 ± 3.1%) was significantly higher than in benign lesions (3.1 ± 3.3%, P = 0.0025) or FGT (1.5 ± 1.2%, P < 0.001), and Dd ((1.29 ± 0.28) × 10−3 mm2/s) was lower than in benign lesions ((1.56 ± 0.28) × 10−3 mm2/s, P = 0.011) or FGT ((1.86 ± 0.34) × 10−3 mm2/s, P < 0.001). A combination of Dd and fp provided higher AUC for discrimination between malignant and benign lesions (0.84) or FGT (0.97) than ADC (0.72 and 0.86, respectively). Conclusion The IVIM parameters provide accurate identification of malignant lesions.

Statistical assessment of bi-exponential diffusion weighted imaging signal characteristics induced by intravoxel incoherent motion in malignant breast tumors

“…IVIM parameters of pseudo-diffusion coefficient (D*), true diffusion coefficient (D) and pseudodiffusion fraction (f) can be determined by fitting DWI signal decay with b-factors to a bi-exponential function. In a number of studies, it has been observed that diffusion signal decay in breast tumors is better fitted by bi-exponential function with smaller residual errors (14)(15)(16).…”

“…Original Article Statistical assessment of bi-exponential diffusion weighted imaging signal characteristics induced by intravoxel incoherent motion in malignant breast tumors such a non-invasive means for simultaneous assessment of tumor diffusivity and vascularity in breast cancer (14,15). According to IVIM principle, diffusion weighted imaging (DWI) signal is not only influenced by true water diffusion in tissue due to the thermal Brownian motion, but also affected by micro-circulation of blood in the randomly structured capillary network, named pseudo-diffusion effect.…”

Diagnostic Significance of Apparent Diffusion Coefficient Values with Diffusion Weighted MRI in Breast Cancer: a Meta-Analysis

“…DWI is capable of differentiating between tissue types on the basis of differences in the ADC and it has been indicated that BC showed restricted diffusion on DWI and had significantly lower ADC values compared with normal and benign breast tissues (Woodhams et al, 2005;Inoue et al, 2011;Lehman, 2012). It is widely accepted that the ADC is related with tissue cellularity and is generally lower in malignant cancers, in which water diffusion is more restricted for the fact that cell density is increased and extracellular space is reduced compared to the normal tissue (Choi et al, 2012;Bokacheva et al, 2013). As we all know, the speed of isotropic, random extracellular movement of water molecules, quantified by DWI as the ADC, is partially affected by the ratio between the volume occupied by cells and the extension of the extracellular space: the higher the ratio the slower the pace of extracellular water movement (Fornasa et al, 2012).…”

Modelling Vascularity in Breast Cancer and Surrounding Stroma Using Diffusion MRI and Intravoxel Incoherent Motion

“…The intravoxel incoherent motion (IVIM) model separates vascular pseudodiffusion from diffusion in the extravascular tissue and has recently been used to model the diffusion signal from breast tumors [4,5], demonstrating a pseudodiffusive contribution to the signal of 6-10% for malignant tissues. This component was less than 2% in noncancerous fibroglandular tissue (FGT), but the regions analysed were in the contralateral breast or at a distance from the tumor.…”

“…A lower bound of 0 was used for all parameters and upper bound of 5x the unweighted signal for S 0 , no bound for ADC or D t and 1 for f p . The data have low sensitivity to D p , so it was fixed at 2 x 10 -2 mm 2 /s similar to previous work [4,5]. The AIC indicates information lost by fitting while accounting for model complexity (lower values indicate less loss) and was calculated by…”