Failure to label red blood cells adequately in daily practice using an in vivo method: methodological and clinical considerations

Abstract

This study was conducted to evaluate the frequency and possible causes of poor red blood cell (RBC) labelling when performing equilibrium gated blood pool (GBP) radionuclide angiography at rest with an in vivo method. The influence of the mode of administration on tagging efficiency was studied by investigating the image quality in 160 patients referred for evaluation of left ventricular (LV) function prior to or after coronary angiography, while using a roughly standardized administration protocol. The patients were subclassified into four groups according to the way both molecules involved in the tagging procedure were administered. When poor image quality was found (in 9.4% of the patients), the labelling efficiency was quantified and the frequency of failed tagging in each group was calculated. A significant association was found between poor labelling and the use of a Teflon catheter or butterfly needle for the injection of the stannous agent. In another 737 patients, in order to avoid the problems observed in the first group, a strict administration protocol was applied to analyse the frequency of poor tagging and its possible causes. Suboptimal image quality was present in 88 patients (11.9%). Quantitatively confirmed poor tagging was present in 36 of the 88 (40.9%, or 4.9% of the whole group); the remaining 52 patients showed borderline normal labelling (> 80% bound fraction). Drug interference was studied by comparing the medications used by the 36 patients showing poor binding with those used by 44 control patients. A significant relationship was found between the use of heparin or chemotherapy and the tagging. The influence of several clinical factors on the labelling was also investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal Biodistribution on 99mTc-Red Blood Cell–Labeled Multigated Acquisition in the Presence of Suspected Cold Agglutinin Disease

“…Cold agglutinin disease may also be secondary to infections such as HIV. Although there are some well-known explanations for alterations in 99m Tc-RBC radiopharmaceutical biodistribution (2), no reports in the literature directly link an abnormal 99m Tc-RBC distribution to cold agglutinin disease. However, in view of a similar incident reported in the literature (1), we suspected cold agglutinin disease as the likely culprit in this nondiagnostic multigated acquisition.…”

Preparation of 99mTc-Nanocoll for use in sentinel node localization: Validation of a protocol for supplying in unit-dose syringes

“…Administration through an intravenous cannula is known to affect the quality of certain 99m Tc radiopharmaceuticals [15][16][17]. The technique of using a non-return R-Lock to simplify the injection of dye after the 99m Tc-Nanocoll therefore had the potential to affect the quality of the radiopharmaceutical by either adsorption of 99m Tc onto some component of the R-Lock or destabilization of the colloid.…”

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

“…Tc-99m-RBC, either in vitro or in vivo, or combined in vivo/in vitro, is the method of choice for routine radionuclide ventriculography. Nevertheless, Tc-99m-HSA still have its role, particularly in some clinical conditions when poor RBC labeling could be expected (7), especially in view of unsuccessful efforts to get a radiopharmaceutical that can be prepared as easily as Tc-99m-HSA, but with better retention in the vascular compartment (12,37). Some preliminary studies in the field appear to be quite promising (22,38).…”