Dynamic contrast-enhanced magnetic resonance imaging: a non-invasive method to evaluate significant differences between malignant and normal tissue

Abstract 

Purpose:

An ever recurring challenge in diagnostic radiology is the differentiation between non-malignant and malignant tissue. Based on evidence that microcirculation of normal, non-malignant tissue differs from that of malignant tissue, the goal of this study was to assess the reliability of dynamic contrast-enhanced Magnetic Resonance Imaging (dcMRI) for differentiating these two entities.

Materials and methods:

DcMRI data of rectum carcinoma and gluteus maximus muscles were acquired in 41 patients.

Using an fast T1-mapping sequence on a 1.5-T whole body scanner, T1-maps were dynamically retrieved before, during and after constant rate i.v. infusion of a contrast medium (CM). On the basis of the acquired data sets, PI-values were calculated on a pixel-by-pixel basis. The relevance of spatial heterogeneities of microcirculation was investigated by relative frequency histograms of the PI-values.

Results:

A statistically significant difference between malignant and normal tissue was found for the mean PI-value (P < 0.001; 8.95ml/min/100g ± 2.45 versus 3.56ml/min/100g ± 1.20). Additionally relative frequency distributions of PI-values with equal class intervals of 2.5ml/min/100g revealed significant differences between the histograms of muscles and rectum carcinoma.

Conclusion:

We could show that microcirculation differences between malignant and normal, non-malignant tissue can be reliably assessed by non-invasive dcMRI. Therefore, dcMRI holds great promise in the aid of cancer assessment, especially in patients where biopsy is contraindicated.

Keywords: Dynamic magnetic resonance imaging, Perfusion, Contrast media, Microcirculation, Rectal carcinoma, Dynamic contrast-enhanced magnetic resonance imaging