Unusual imaging of varicose veins after radiolabeling of autologous low-density lipoproteins.

LDL-radiolabeling with various isotopes (123I, 125I, 131I, 111In, 99mTc and 67Ga, among others) has been used for imaging the arterial wall, monitoring the LDL-kinetics and in particular to assess vascular surface lining and foam cell content. From 286 patients studied with 111In-LDL scintigraphy, only 9 patients presented clinical varicosis. In 2 of these 9 patients a predominant imaging of varicose veins has been shown with scintigraphy, while in the other 7 patients no positive scintigraphic imaging could be detected. In vitro and in vivo perfusion experiments did not reveal an explanation for this unusual results. The reason for that positive LDL-uptake into varicose veins is unknown. These findings indicate that localized LDL-uptake has to be interpreted carefully in order to avoid potential false positive results.