Ts. Desser et al., Interstitial MR and CT lymphography with Gd-DTPA-co-alpha,omega-diaminoPEG(1450) and Gd-DTPA-co-1,6-diaminohexane polymers: Preliminary experience, ACAD RADIOL, 6(2), 1999, pp. 112-118
Rationale and Objectives, The authors assessed the efficacy of two gadolini
um-based polymers used as lymphotrophic contrast media for computed tomogra
phy (CT) and magnetic resonance (MR) imaging.
Materials and Methods. Two gadolinium-based polymers, gadolinium diethylene
triaminepentaacetic acid (DTPA)-co-1,6-diaminohexane (NC 22181) and Gd-DTPA
-co-alpha, omega-diamino-polyethylene glycol(1450) (NC-66368), were formula
ted at a concentration of 80 mmol/L gadolinium. Doses of 0.1, 0.25, 1.0, or
2.0 mL per paw were administered subcutaneously into the hindpaws of norma
l rabbits. Spin-echo T1-weighted MR imaging (1.5 T) of rabbit popliteal and
iliac nodes was performed before and immediately, 10 minutes, 2-3 hours, a
nd 24 hours after injection. CT was performed 2-3 hours after injection of
the high doses only.
Results. MR imaging revealed prompt enhancement of the popliteal nodes with
both polymers at doses of 0.25 mL and above. For doses of 1.0 mL or less p
er paw, nodal percentage enhancement was maximal at 2 hours and then declin
ed at 24 hours. At the highest doses, however, a reservoir of subcutaneous
contrast material remained at the injection site and resulted in peak enhan
cement at 24 hours. At CT, popliteal node enhancement was faintly visible 2
-3 hours after the administration of NC 22181. At lower doses, no enhanceme
nt was appreciable at CT.
Conclusion. At 80 mmol/L formulations, the two gadolinium-based polymers pr
ovide excellent popliteal nodal enhancement on MR images. In addition, high
doses of one polymer (NC 22181) were sufficiently concentrated. In poplite
al nodes to be visible on CT scans. Thus, this agent may be useful for both
CT and MR lymphography.