Equivalent cross-relaxation rate imaging of breast cancer

Purpose: To determine whether equivalent cross-relaxation rate (ECR) imaging is a feasible method for demonstrating breast cancer.

Materials and methods: Fifteen breast cancer patients underwent both ECR imaging, with off-resonance saturation pulses at frequency offsets of 7 and 19 ppm (ECR-7 and ECR-19, respectively) from water resonance, and gadolinium (Gd)-enhanced dynamic magnetic resonance imaging (MRI) of the breast. The mean tumor size was 26.5 mm. The tumor outlines defined by their shape and margin on ECR-7 images were compared with the subtraction images produced by the dynamic study, and the distribution of hyperintensity areas and their shapes on ECR-19 images were assessed. All patients had surgery and pathological findings were compared to ECR images.

Results: The tumor outline of 13/15 (87%) tumors on ECR-7 images was nearly identical to that on subtraction images; ECR-19 images demonstrated the location and degree of fibrosis. The tumor outline of the other two tumors was less clear on ECR-7 images, and internal hyperintensity on ECR-19 images reflected intratumoral fibrotic foci. ECR-7 and -19 imaging findings allowed identification of four distinct tumor types that reflected the tumor growth patterns and their internal structures associated with fibrosis.

Conclusion: ECR imaging is a feasible imaging technique for demonstrating breast cancer.