MRI Detection of Small Calcium Crystals in Air Bubble-free Agarose Phantoms: Potential Applications to Imaging Microcalcifications in Breast Cancer

Introduction: Clusters of calcium oxalate (CaOX) and hydroxyapatite (CaHA) crystals are generally associated with benign and malignant breast lesions, respectively. Such microcalcifications (microcalcs) are useful radiological indicators of early-stage, breast carcinoma. This study tests the detectability of these microcalcs by MRI, compared to conventional x-ray imaging methods, for potential clinical applications in improved breast cancer detection. Novel air bubble-free, ultra-pure agarose phantoms were specifically developed for these MR imaging studies. Such phantoms may be easily modified for other imaging applications. Herein, MR images of microcals embedded in air bubble-free agarose phantoms were collected at high (9.4 Tesla) and at low (1.5 Tesla) field strengths, for comparison with traditional x-ray mammograms. Both calcium types were detectable and distinguishable on MR images, most likely due to unique susceptibility artifacts, while they appeared similar on x-ray mammograms.