FIGURE 2. (A) Diagrammatic representation on logarithmic scale of approximate ranges of particle size of different 99mTc-labeled colloids for lymphoscintigraphy, as derived from various sources (manufacturers, publications). Discrepant data (indicated by additional lines in graph) are occasionally reported by different authors for some radiopharmaceuticals, depending on factors such as measurement method, stability of agent after radiolabeling, and in-house modifications of reconstitution procedure. The 2 ranges represented for filtered sulfur colloid refer to presumed ranges obtained after filtration through 100- or 220-nm filter. (B) Examples of variable estimates of particle size distribution for 99mTc-antimony sulfide and 99mTc-rhenium sulfide when assessed by different methods. HSA = human serum albumin; MF = membrane filtration; PCS = photon correlation spectroscopy; TEM = transmission electron microscopy (modified from Tsopelas (70)).
