Figure 3. Imprecision of circulating blood volume obtained by the131I-HSA method in comparison with pulse dye-densitometry (PDD)(nose, left; finger, right). A closer imprecision was found in nose than in finger. The imprecision is almost identical to the bias between the131I-HSA dilution method and in vitro spectrophotometry (Figure 5). RI =131I-HSA method.