Imaging recommendation · Vascular

Acute limb ischemia (pain, pallor, paresthesia, paralysis)

Q: What's the alternative imaging for acute limb ischemia (pain, pallor, paresthesia, paralysis) when iodinated contrast contraindicated?

MRI — MR Angiography Aorta and Runoff (iv contrast).

Recommended: CTA Aorta and Lower Extremity Runoff is the preferred imaging study for acute limb ischemia (pain, pallor, paresthesia, paralysis). Rutherford classification guides revascularization urgency.

Recommended study

CTA Aorta and Lower Extremity Runoff

CT IV contrast Preferred Vascular Emergency Reviewed 2026-05

Rutherford classification guides revascularization urgency. Embolic vs thrombotic distinction important.

If the default doesn't apply

Iodinated contrast contraindicated

MRI MR Angiography Aorta and Runoff IV contrast

On-table imaging during intervention

Catheter DSA IV contrast

Watch-outs

Rutherford IIb (immediate threat)

Sensory loss + motor deficit — revascularization within 6 hours; do not delay for full work-up.

Rutherford III (irreversible)

Paralysis, profound sensory loss, absent Doppler — limb is not salvageable; amputation planning.

Pearls

Six P's: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia.
Embolic: cardiac source (AF) — abrupt onset, no collaterals, contralateral pulses present.
Thrombotic: chronic PAD with acute exacerbation — more gradual onset, collaterals present.