Potential Pitfalls When Differentiating Hemorrhage and Calcium on Susceptibility-Weighted Images

The imaging phase data captured by MR susceptibility-weighted imaging (SWI) can provide biochemical information not currently evaluable by other MR imaging techniques, such as distinguishing between calcium and hemorrhage. We presented a case that illustrates the use of internal controls within filtered phase images, such as intracranial veins and pineal and/or choroid calcifications, to improve the reliability of using phase images to differentiate calcium and blood products. We also described how to avoid pitfalls in interpreting susceptibility-driven phase aliasing and dipole field effects.