Table 1 Molecular imaging for breast cancer

Radionuclide imaging

Positron emission tomography

Detection

Wide range of molecular imaging probes

Limited spatial resolution (improved with use of non-contrast computed tomography)

Response evaluation

Tumor characterization

Tracer imaging without perturbing biologic system

Some radiation exposure

Positron emission

mammography

Detection

Tumor characterization

More sensitive for smaller tumors

Higher spatial resolution

Increased radiation dose

Visualization of posterior lesions

Variable uptake of

¹⁸F-fluorodeoxyglucose (FDG) in small

and less metabolically active tumors

Breast-specific gamma imaging

Detection

More sensitive for smaller tumors

Heavy compression of breast tissue

not required

Associated with radiation exposure

Best combined with anatomic imaging

(mammography) for optimal screening Longer imaging time

Some radiation exposure

Magnetic resonance

Magnetic resonance imaging

(MRI), especially dynamic

contrast-enhanced MRI and

targeted contrast agents

Tumor characterization

Quantification of tumor perfusion

and tumor capillary permeability

Confined space

Contrast design limited by need for

magnetic atom

Magnetic resonance spectroscopy

Tumor characterization

Can measure wide range of molecules

No contrast necessary

Limited spatial resolution

Challenging to obtain high-quality

spectra in routine imaging

Ultrasound, especially with

contrast enhancement

Detection

Tumor characterization

Highly portable, inexpensive

Molecular microbubble agents possible

Operator dependence

Contrast agents confined to vascular

space thus far

Optical imaging

Tumor characterization

Inexpensive, highly portable, and does

not necessarily require a contrast agent

Limited depth penetration, challenging

spatial localization, and operator

dependence