Fig. 1
From: A gamma-distribution convolution model of 99mTc-MIBI thyroid time-activity curves
The top left panel (a), shows a region of interest (ROI) drawn over a right thyroid lobe of an example one-minute image from a 99mTc-MIBI gamma camera image sequence. The top right panel (b) shows the ROIs time-activity curve (TAC). Panel (c) shows the same right thyroid lobe TAC as in panel (b) with time on a logarithmic scale to better display the rapidly changing curve at early times. Superimposed is the fit of a gamma distribution convolution (GDC, solid red line) scaled to the TAC showing a good fit to the TAC (open circles). Panel (d) shows graphical representations of the GDfast, the fast vascular gamma distribution (F, orange); GDWO, the washout gamma distribution (W, green) and the GDC; the convolution of GDfast and GDWO (G, blue). For clarity, the vertical axis has an arbitrary scale to superimpose the GDfast function with the other two functions on one graph. Note that although the GDWO eventually converges to the GDC model, this takes a long time to occur