Table 1.

Imaging modalities general characteristics

Modality	Physical principle	Spatial resolution	Parameters imaged	Depth	Acquisition time	Cost per scana (US $)
PET	Radioactivity	1–2 mm	Metabolism, immunology	No limit	minutes/hours	$1000–$2000
SPECT	Radioactivity	1–2 mm	Metabolism, immunology	No limit	minutes/hours	$1000–$1500
MRI	Electro-magnetism	< 100 µm	Structure, metabolism	No limit	minutes/hours	$800–$1200
CT	X-ray	< 100 µm	Structure	No limit	seconds	$600–$800

^aCost per scan may vary depending on the injected dose price. Adapted from [52]