Figure 1From: Role of positron emission tomography in lung cancerAn illustration of how the detection of small tumours by PET is not determined by spatial resolution. The text on the left is displayed with high spatial resolution but is unable to detect the hidden message ‘CANCER’. Even though the text on the right is blurred (low resolution), the hidden message is revealed by labelling the letters that are functionally different (i.e. they carry the hidden message).Back to article page