Characterization of T1 relaxation and blood-myocardial contrast enhancement of NC100150 injection in cardiac MRI

A new ultrasmall superparamagnetic iron oxide (Clariscan; NC100150 Injection) was studied in domestic farm pigs. The T1 effects were characterized for blood and myocardium and the blood-myocardial contrast was measured in T1-weighted cine images. The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured at baseline and contrast doses of 1 and 5 mg Fe/kg body weight (bw) at end diastole and late systole. The T1 values for blood and myocardium were reduced by 97 and 43%, respectively, from baseline to 5 mg Fe/kg bw. The CNR was significantly improved with contrast at end diastole and late systole. The maximum improvement shown was 202% at 5 mg Fe/kg bw in late systole. The percent SNR enhancement was significantly higher in blood than myocardium at late systole. NC100150 Injection is an effective T1 shortening agent and can be used to improve blood-myocardial contrast in cine images of the heart.