Diagnosing iliofemoral vein occlusion from radionuclide blood pool venography.
There have been reports regarding the efficacy of Tc-99m labeled RBC venograms. The authors have found that potentially dangerous iliac vein occlusions can be missed unless especially careful attention is paid in looking for any asymmetry of the iliac vessels with respect to intensity, thickness, and/or definition, along the whole or at least 50% of one of the vessel's length, and the presence or absence of blood pool activity in the most proximal portion of the left common iliac vein, i.e., whether the activity arises from the IVC or the aorta. Eight (21%) of 38 consecutive labeled RBC venograms performed at this institution over six months produced findings that met criteria and/or. Iliofemoral vein occlusion was confirmed in six of the eight patients (16% of all patients). Thus, while the above criteria are not pathognomonic for iliofemoral vein occlusion, their rigid application has enabled the authors to detect a significant proportion of patients with iliofemoral occlusions which would otherwise have gone undetected. All eight cases were confirmed by further workup with direct injection radionuclide venography or contrast venography.