Click on image to view larger version.
FIGURE 1. Sample PET images from patient PH226 (Table 1) with pulmonary edema. (A) Transmission image. Scale is in arbitrary units, where higher numbers indicate greater attenuation of activity (i.e., greater tissue density). Scan is comparable with typical CT scan, except with approximately 1/10th the spatial resolution. Scan is used to identify lung regions (white outlines). (B) PBF image. Units are mL/min/100 mL lung. (C) Lung water concentration (LWC) image. Units are mL H2O/100 mL lung. Normal upper limits for LWC by these methods are approximately 25 mL H2O/100 mL lung. Note dorsal predominance of lung water accumulation. Also note general concordance between regional blood flow and lung water distributions (i.e., there is no appreciable perfusion redistribution away from regions of increased LWC [pulmonary edema]).
