Table 1.

Summary of imaging modalities used to image small animal abdominal aortic aneurysms.

Modality	Capabilities		Application		Contrast Agents/ Radionuclide Tracers
	Anatomical	Molecular/ Functional	Benefits	Limitations
Ultrasound	X		Rapid, accurate, low cost, reproducibility, widely available	Limited resolution, image interpretation difficult, artifacts common	Microbubbles
CT	X		Rapid, high resolution, useful for early clinical followup	Ionizing radiation, requires contrast agent	Iodine or Barium
MRI	X		Soft tissue contrast, high resolution	High cost, large equipment required	Gadolinium chelates
		X	Customizable molecular targeting, cell tracking	Limited sensitivity, requires contrast agent	USPIOs or gadolinium chelates
NIRF		X	Low cost, widely available	Photobleaching, low quantum yield, shallow tissue penetration	MMPSense, scVEGF/Cy, RGD-HFn-Cy5.5
Bioluminescence		X	High sensitivity, high specificity	Shallow tissue penetration, requires transgenic modification	Exotic transgenic cells combined with luciferin
SPECT		X	3D imaging, widely available, highly sensitive, simultaneous imaging of multiple processes	Limited temporal resolution, few radionuclide tracers	99TC, 111In, 201Tl, 123I, 131I
PET		X	Quantification of metabolism and blood flow, high sensitivity, many radionuclide tracers available	High cost, limited availability, large equipment required, short tracer half-life, single process evaluation	18F, 11C, 13N, 15O, 82RB