Michele Anzidei MD, Presenter: Nothing to Disclose

Alessandro Napoli MD, Abstract Co-Author: Nothing to Disclose

Carlo Catalano MD, Abstract Co-Author: Nothing to Disclose

Roberto Passariello MD, Abstract Co-Author: Nothing to Disclose

To measure the T1 trend in blood after the administration of Gadobenate Dimeglumine (Gd-BOPTA, MultiHance®, Bracco Spa, Milan - Italy) in humans.

In a pilot study for parameters optimization, the T1-shortening induced by the injection of a single dose (0.1 mmol/kg body weight) of the MR contrast agent MultiHance® was measured at B0=1.5 T as a function of time. In four sessions, T1 measurements were performed in the carotid artery of 10 volunteers up to 30 min after injection. T1 times were measured using 2D IR-FLASH sequences: 10 images acquired with different TI were used to evaluate the T1 before contrast administration, while three 2D IR-FLASH with different TI (130, 800 and 3000 ms) were performed for each time point after contrast agent injection.

The 2D IR-FLASH measurements showed T1 times of about 130 ms immediately after injection, which gradually increased to 400 ms at 30 min. The time curve of the R1=1/T1 averaged over all volunteers could be described with a bi-exponential decay with time constants C1 = 380+/-70 s and C2 = 5600+/-126 s, amplitude A1= 4.3+/-0.3 s-1 and A2=2.7+/-0.3 s-1 respectively, and a constant offset of R1(0)=0.5+/-0.2 s-1. Mean relaxation values are in excellent agreement with theoretical predictions.

An analytical expression for the initial T1-shortening of MultiHance® was derived which can now be used for optimization of the pulse sequence parameters in clinical studies.

The trend of T1 values of blood during the administration of Multihance® can be used to optimize sequence protocols for MR-angiography.

Anzidei, M, Napoli, A, Catalano, C, Passariello, R, In Vivo Measurements of Human Blood T1 Trend after the Administration of Gadobenate Dimeglumine.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8006775.html