Analysis of red cell mass and plasma volume in patients with polycythemia.

Context: Polycythemia describes an increased proportion of red blood cells in the peripheral blood. In absolute polycythemia, there is increased red cell mass (RCM) with normal plasma volume, in contrast with apparent polycythemia, in which there is increased or normal RCM and decreased plasma volume. In order to deliver the appropriate treatment it is necessary to differentiate between the two.

Areolar-cutaneous "junction" injections to augment sentinel node count activity.

Purpose: The authors report on a modified lymphoscintigraphy protocol for increasing activity in the sentinel node (SN) through a specific technique (LymphoBoost). It consists of an areolar-cutaneous "junction" injection, using a very shallow, high-volume, high-specific-activity injection of 100% filtered Tc-99m sulfur colloid, as an adjunct to their standard protocol.

Materials And Methods: Results from a previously optimized protocol (group 1, n = 28) were compared with those from their new protocol (group 2, n = 85), which consisted of two sets of consecutively applied (within 12 to 20 minutes) injections: group 2A composed of perilesional and intradermal injections (similar to the previous group 1) followed by group 2B LymphoBoost injections within 12 to 20 minutes in the same patients.

Effect of high specific-activity sulfur colloid preparations on sentinel node count rates.

Purpose: Preliminary results by other investigators suggest that increasing the specific activity of Tc-99m nanocolloid preparations increases the measured counts in sentinel nodes compared with lower specific-activity (SA) preparations using the same initial injected dose. The authors set out to determine whether a similar result could be perceived with Tc-99m sulfur colloid (SC) preparations.

Methods: Twenty-three consecutive patients (low SA group) with successful visualization of sentinel nodes by lymphoscintigraphy before our standard protocol was changed to a higher SA preparation were compared with 28 patients (high SA group) just after the switch.

Scintigraphic evaluation of Tc-99m-low-density lipoprotein (LDL) distribution in patients with Gaucher disease.

Gaucher disease (GD) is frequently associated with reduced plasma levels of low density lipoproteins, presumably due to increased catabolism of LDL. The purpose of this study was to determine the distribution of Tc-99m LDL (Tc-LDL) in Gaucher patients, and compare the findings to bone marrow distribution. Four patients with non-neuropathic Gaucher disease (type 1) underwent baseline whole body imaging at 4 and 24 h after injection of dialyzed autologous LDL labeled with 10-20 mCi Tc-99m-pertechnetate.