MULTIMODALITY COMPARATIVE STUDY: QUANTITATIVE ASSESSMENT OF MRI CONTRAST AGENT DOSE REDUCTION

Abstract

Contrast agents are used in 30–40% of diagnostic MRI scans. These agents are expensive and cause adverse effects in some patients. One way to reduce the amount of contrast agent needed would be to improve the signal-to-noise ratio (SNR). We hypothesized that pre-magnetizing samples of the paramagnetic contrast agent gadodiamide before scanning would increase the SNR. Samples of gadodiamide in saline were magnetized with a permanent magnet before being placed in a phantom and scanned in either a closed 1.5 T MRI or an open 0.35 T MRI. Samples were scanned 0–5 hours after magnetization. Samples of gadodiamide that had not been magnetized were also scanned. In the 1.5 T instrument, we found an increase in SNR in pre-magnetized samples that was highest three hours after magnetization, up to a 1.8-fold increase at low concentrations of gadodiamide. The improvement in SNR was more modest in the low-field MRI scanner, peaking two hours after magnetization. This relatively simple method has the potential to reduce the amount of contrast agents needed for diagnostic MRI scans.