In vitro investigation of poor cerebrospinal fluid suppression on fluid-attenuated inversion recovery images in the presence of a gadolinium-based contrast agent

Cerebrospinal fluid (CSF) enhancement on fluid-attenuated inversion recovery (FLAIR) images obtained post-gadolinium (Gd)-based agent injection is described in stroke and multiple sclerosis. Blood brain barrier (BBB) disruption with contrast agent extravasation into CSF shortens T(1) relaxation times, reducing fluid suppression. Reduced fluid suppression on FLAIR images was investigated in vitro in the presence of escalating gadopentetate dimeglumine (Gd-DTPA) concentrations mixed with artificial CSF. Low Gd-DTPA concentrations impair fluid suppression of FLAIR imaging in association with progressively reduced T(1) values. At higher concentrations, the prevalent T(2) shortening effect can explain signal intensity (SI) reduction. Post-Gd FLAIR may be useful in detecting subtle BBB leakage.