A hypervascular "hot spot" intramyoma nodule was the diagnostic clue in a clinical context of hematogenous tumor spread of thyroid origin (increased thyroglobulin level).
The % of Tg rise = [serum Tg on day-4 - baseline serum Tg]/[baseline serum Tg] * 100 while the nodule shrinkage as measured by volume reduction ratio (VRR) = [baseline volume - volume at 6-month]/[baseline volume] * 100.