Diffusion-Weighted Imaging of Malignant Breast Tumors

Abstract

The authors used breast diffusion-weighted imaging (DWI) to diagnose breast cancer and identify cancer extension. Isotropic DWI was performed with EPI. The apparent diffusion coefficient (ADC) value was calculated and displayed on an ADC map. The authors compared between the distribution of low ADC values and pathologic cancer extension. The mean ADC value of breast cancer was 1.12 +/- 0.24 x 10(-3) mm/s, which was lower than that of normal breast tissue. The ADC value for invasive ductal carcinoma was lower than that of noninvasive ductal carcinoma. The sensitivity of the ADC value for breast cancer using a threshold of less than 1.6 x 10(-3) mm/s was 95%. Seventy-five percent of all cases showed precise distribution of low ADC value as cancer extension. The causes of underestimation were susceptibility artifact from bleeding and the limit of spatial resolution. Benign proliferative change showed a low ADC value. The authors conclude that DWI has a potential for clinical appreciation in detecting breast cancer.

Correlation of the apparent diffusion coefficiency values on diffusion-weighted imaging with prognostic factors for breast cancer

“…A decrease in the ADC is expected with increased intracellular tissue caused either by cell swelling or increased cellular density rather than vascular perfusion. HER2-positive expression had a more malignant phenotype accompanied by cell proliferation, invasion and metastasis [1,2,8]. However, in our study, no statistically significant difference was observed between the negative and positive group of IDC NOS.…”

“…In vivo, the ADC value is affected not only by microscopic motion from diffusion but also perfusion. The perfusion effect would cause significantly greater artificially increased ADC in malignant lesions owing to increasing microvessel count of tumour angiogenesis [1,2,22,28]. According to several studies, the ADC value was significantly lower in malignant than in benign lesions, indicating that this effect might be mainly owing to the effect of high cell density overcoming the opposite effects of perfusion [1,5,14].…”

“…Water diffusion is greatly influenced by factors such as cellularity, fluid viscosity, intra-and extracellular membrane permeability, active transport, flow and structural directionality [1,9,22]. Several studies have reported that malignant tumours usually show higher signal intensity on DWI, compared with benign lesions and normal fibroglandular tissue, resulting in lower ADC values [2,3,5,7,[9][10][11][12]21]. It has been suggested that the decreased ADC value in malignant tumours may be due to their increased cellularity, larger nuclei with more abundant macromolecular proteins, and less extracellular space [5,20].…”

“…The ADC is a quantifiable value that provides a measurement of signal attenuation and is affected by microscopic motion, including molecular diffusion of water and blood microcirculation in the capillary network [1][2][3][19][20][21]. Water diffusion is greatly influenced by factors such as cellularity, fluid viscosity, intra-and extracellular membrane permeability, active transport, flow and structural directionality [1,9,22].…”

“…Breast MRI is an established supplemental technique to mammography and ultrasonography for evaluation of suspicious breast lesions. Diffusion-weighted MRI (DWI) has recently been integrated into the standard breast MRI for discrimination of benign and malignant breast lesions obtained with dynamic contrast-enhanced MRI [1][2][3][4][5][6][7][8][9][10][11][12][13]. DWI is a non-invasive technique that represents the biological character of the mainly Brownian movement of protons in bulk water molecules in vivo.…”