Torel Ogur MD, Presenter: Nothing to Disclose

Patrick T. Norton MD, Abstract Co-Author: Nothing to Disclose

Klaus D. Hagspiel MD, Abstract Co-Author: Research Grant, Siemens AG

To evaluate the effect of automatic bone and plaque removal on image quality and grading of stenoocclusive lesions in peripheral arterial disease (PAD) patients undergoing dual energy CT angiography (DE-CTA) of the lower extremity (LE) and to compare with digital subtraction angiography (DSA) as the reference standard.

Twenty one PAD patients underwent both DE-CTA and DSA (13 men, 8 women, mean age 62.8 years; range 40–91). DE-CTA (Siemens Somatom Definition Flash, Siemens Medical Solutions, Forchheim, Germany) was performed within a month of the intraarterial DSA (Axiom Artis Siemens Medical Systems, Forchheim, Germany). We compared the results of image interpretation based on axial source images and MPR images without (SIMPR) and with dual energy bone and plaque removal (DEBPR) with DSA. Fifteen arterial segments per lower extremity were analyzed with the segments classified into 3 groups - inflow, outflow and runoff. The sensitivity (SE), specificity (SP) and diagnostic accuracy (ACC) for the detection of relevant stenosis (>69%) or occlusions for each set of images were calculated against DSA findings as the reference standard.

A total of 323 segments for 21 patients (25 LE arteries) were evaluated. For inflow vessels; SE, SP, and ACC were 83.33%, 98.18% and 96.72%, respectively for SIMPR, and 100% for all three for DEBPR. For outflow vessels SE, SP, and ACC were 76.19%, 94.12% and 89.88% for SIMPR, and 100%, 91.18% and 93.25% for DEBPR. For runoff vessels we found 67.24%, 80.87% and 76.30% for SIMPR, and 91.38%, 70.43% and 77.45% for DEBPR.

DECT based plaque and bone removal improves the sensitivity, specificity and accuracy of lower extremity CTA, particularly for the inflow and outflow vessels. The automated plaque removal tool improves luminal assessment and the automated bone removal tool allows reliable segmentation of bone.

Dual energy based automated bone and plaque subtraction allows to improve the sensitivity, specificity and accuracy of lower extremity CTA over conventional CTA, particularly in the iliofemoral and popliteal arteries.

Ogur, T, Norton, P, Hagspiel, K, Dual-Energy CT Angiography for the Assessment of Lower Extremity Peripheral Arterial Disease.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015226.html