The purpose of this study was to assess the diagnostic accuracy of dynamic computed tomographic angiography (dyn-CTA) in patients with critical lower leg ischemia.
A population of 29 patients with known peripheral arterial occlusive disease (Fontaine stage III or IV) was examined with a combined CTA protocol consisting of a standard CTA (s-CTA) of the lower leg runoff from the diaphragm to the toes and dyn-CTA of the calves (scan range, 48 cm; 8 phases; 3.5 seconds per phase, 100 kV; 120 mAs; contrast volume, 50 mL; flow rate, 5.0 mL/s). Digital subtraction angiography was performed on all patients and served as a reference standard. For each of seven lower leg artery segments, arterial contrast and diagnostic confidence for stenosis assessment (3-point scale) were tested for s-CTA and dyn-CTA. Similarly, stenoses of calf-segments were classified on a 3-point scale separately for s-CTA and dyn-CTA and were compared with digital subtraction angiography to assess diagnostic accuracy.
Compared with s-CTA, dyn-CTA resulted in significantly higher arterial contrast enhancement (68% vs 46% optimal contrast; P < 0.01) and higher diagnostic confidence (64% vs 48% fully confident, respectively, P < 0.05). Dyn-CTA had a slightly higher sensitivity for the detection of significant stenosis (98.0% vs 96.6%), and for the detection of occlusion (95.4% vs 94.4%). Specificity for dyn-CTA was higher than for s-CTA, both for detection of stenosis (97.1% vs 92.2%) and especially for the detection of vessel occlusions (99.3% vs 94.4%; P < 0.05).
Compared with s-CTA, dyn-CTA provides improved arterial contrast enhancement, higher diagnostic confidence, and increased diagnostic accuracy for the detection of stenoses and occlusions in peripheral arterial occlusive disease patients.
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From the Departments of *Clinical Radiology and †Surgery, University Hospitals-Grosshadern, Ludwig-Maximilians University, Munich, Germany.
Received June 12, 2011, and accepted for publication, after revision, November 27, 2011.
Conflicts of interest and sources of funding: none declared.
Reprints: Wieland H. Sommer, MD, Department of Clinical Radiology, University of Munich, Grosshadern Campus, Marchioninistr 15, 81377 Munich, Germany. E-mail: firstname.lastname@example.org.
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