Contrast agents and temporal resolution in breast MR imaging.

The article summarizes the technique of dynamic Gd-enhanced breast magnetic resonance (MR) imaging and the established clinical indications to this examination. The main features of the four different non-selective Gd-chelates today available for contrast-enhanced MR breast imaging are described. Their typical two-compartment (vascular/interstitial) distribution is related to the temporal resolution used for the MR acquisition; the gain in specificity obtained increasing the temporal resolution during the first phase after the contrast intravenous injection (using both, rapid T1-weighted sequences or ultrafast T2*-weighted perfusion imaging) is discussed. Moreover, a survey of new contrast agents is supplied, including a high T1-relaxivity Gd-chelate, blood pool agents, and lymph node targeted agents. In conclusion, future directions are delineated.