Markedly Increased Volume of Distribution of Gadolinium in Cardiac Amyloidosis Demonstrated by T1 Mapping

PurposeTo perform myocardial T-1 mapping pre- and post-gadolinium (Gd) administration and determine the volume of distribution of Gd (Vd(Gd)) in patients with cardiac amyloidosis to assess extracellular space expansion from amyloid protein deposition. Materials and MethodsT(1) mapping was performed before contrast and 20 minutes following bolus administration of 0.15 mmol/kg of gadopentetate dimeglumine (Magnevist) in five subjects with cardiac amyloidosis and in eight healthy volunteers using previously validated 3-5 Modified Look-Locker Inversion (MOLLI) pulse sequence. The partition coefficient () and Vd(Gd) were determined and compared between groups. ResultsBefore contrast the T-1 of the blood and myocardium are longer in amyloidosis as compared to controls (1665 vs. 1509 msec; P = 0.03 and 1144 vs. 963 msec; P < 0.001, respectively). Postcontrast blood T-1 was also significantly longer in amyloidosis (486 vs. 408 msec; P = 0.003) with a trend towards shorter T-1 in the myocardium (503 vs. 544 msec; P = 0.15). The Vd(Gd) was 83% higher in amyloidosis than in controls (0.51 vs. 0.28; P = 0.005). ConclusionMyocardial Vd(Gd) is markedly increased in cardiac amyloidosis, reflecting the increased extracellular space occupied by amyloid proteins. The precontrast T-1 of blood and myocardium are increased in amyloidosis extending diagnostic utility in patients who cannot receive Gd. J. Magn. Reson. Imaging 2013;38:1591-1595. (c) 2013 Wiley Periodicals, Inc.