Automatically Identifying Fusion Events between GLUT4 Storage Vesicles and the Plasma Membrane in TIRF Microscopy Image Sequences

Figure 3

Four typical identification results compare to ground truth. Relationship between the variety of total instensity, intnesity at weighted centroid, and spot radius during vesicle movement. The integral average radius is also calculated (red dashed line) as a threshold for identifing diffusion initiation (>1.2 times, black asterisk) and fusion event (>2 times). (c) A nonfusion at the edge of cell is mistakenly identified as a fusion event, mainly due to unsymmetrical background. All values are normalized to the initiation of fusion pore opening.

(a) A genuine fusion event is correctly identified (TP)

(b) A genuine fusion event is mistakenly identified as a nonfusion event (FN)

(c) A nonfusion event is mistakenly identified as a fusion event (FP)

(d) A nonfusion event is correctly identified (TN)