(A) Maximum-intensity projection shows mild residual activity along tubing and catheters, with focus of intense activity at stopcock junction. (B) Mild residual activity at bottom of v-vial. (C) Intense residual activity clearly localized to stopcock junction. (D) Stopcock junction as shown on low-dose CT. Volume of interest is encircled. MTV = metabolic tumor volume; S = stopcock junction; V = v-vial. Color version of this figure is available as supplemental file at http://tech.snmjournals.org.