In the example shown, two different microorganisms are tested by both methods against the same antibiotic.
 The MIC of the antibiotic for the susceptible microorganism is 8 µg/ml. 
The corresponding disk diffusion test shows a zone of inhibition surrounding the disk. 
In the second sample, a resistant microorganism is not inhibited by the highest antibiotic concentration tested (MIC > 16 µg/ml) and there is no zone of inhibition surrounding the disk.
 
The diameter of the zone of inhibition is inversely related to the MIC.