Harika L, Weissleder R, Poss K, Papisov M I
Department of Radiology, Massachusetts General Hospital, Boston, USA.
Radiology. 1996 Feb;198(2):365-70. doi: 10.1148/radiology.198.2.8596833.
To determine the pharmacokinetic and magnetic resonance (MR) imaging properties of diethylenetriaminepentaacetic acid (DTPA) conjugated with a polyglucose-associated macrocomplex (PGM), which accumulates in lymph nodes.
In 124 normal and 20 tumor-bearing rats, Gd-DTPA PGM was administered intravenously in doses of 2, 10, 20 mumol gadolinium per kilogram of tissue.
Mean blood half-life was 2 hours. Maximum accumulation in peripheral (33.0% injected dose [ID]/g +/- 16.2 [standard deviation]) and central lymph nodes (63.2% ID/g +/- 16.5) was observed within 24 hours after administration. The optimum dose range was 10-20 mumol Gd/kg in rats. At 24 hours after administration of 20 mumol Gd/kg, the signal-to-noise ratio increased from 30.9 +/- 0.4 to 83.2 +/- 5.2 in normal lymph nodes (P < .001). Differentiation between normal and metastatic lymph nodes was improved.
When labeled with Gd-DTPA, the PGM-based graft copolymer significantly increases signal intensity at MR imaging of normal but not metastatic lymph nodes without causing distortion artifacts.
