Published in:
01-12-2010 | Computed Tomography
Diagnostic value of time-resolved CT angiography for the lower leg
Published in: European Radiology | Issue 12/2010
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Objective
The aim of this study was to test the feasibility of time-resolved computed tomography angiography (TR-CTA) for use in the lower leg.
Methods
Fifty-nine patients with suspected peripheral arterial occlusive disease were examined with a standard CTA (S-CTA) of the lower run-off and with an additional TR-CTA of the calves (12 phases; 2.5 s/phase, 80 kV, 120 mAs, volume of contrast medium 50 mL, flow rate 5.0 mL/s). For seven lower-leg artery segments, arterial contrast and the presence of venous overlay were tested for S-CTA and TR-CTA. Stenoses were classified on a three-point scale separately for S-CTA and TR-CTA, and diagnostic confidence for stenosis assessment was evaluated for both datasets. Contrast arrival times and HU values were evaluated in patients with asymmetric proximal stenoses.
Results
TR-CTA resulted in significantly higher contrast enhancement (P < 0.0001) and less venous overlay as compared to S-CTA (P < 0.05). Diagnostic confidence for stenosis rating was significantly higher in TR-CTA (P < 0.0001). Asymmetric proximal stenoses lead to significantly delayed and diminished contrast enhancement on the stenotic side.
Conclusion
TR-CTA of the calves is feasible and provides higher enhancement and higher diagnostic confidence as compared to monophasic CTA of the lower legs.