Dual-Energy CT Angiography in Peripheral Arterial Occlusive Disease

Abstract

We sought to study the accuracy of dual-energy computed tomographic angiography (DE-CTA) for the assessment of symptomatic peripheral arterial occlusive disease of the lower extremity by using the dual-energy bone removal technique compared with a commercially available conventional bone removal tool. Twenty patients underwent selective digital subtraction angiography and DE-CTA of the pelvis and lower extremities. CTA data were postprocessed with two different applications: conventional bone removal and dual-energy bone removal. All data were reconstructed and evaluated as 3D maximum-intensity projections. Time requirements for reconstruction were documented. Sensitivity, specificity, accuracy, and concordance of DE-CTA regarding degree of stenosis and vessel wall calcification were calculated. A total of 359 vascular segments were analyzed. Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%. Best results for both postprocessing methods were achieved in the vascular segments of the upper leg. In severely calcified segments, sensitivity, specificity, and accuracy stayed above 90% by the dual-energy bone removal technique, whereas the conventional bone removal technique showed a substantial decrease of sensitivity, specificity, and accuracy. DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.

Assessment of occlusive disease of lower extremity arteries on the basis of anatomic region: Value of 128-slice multidetector CT angiography in comparison with digital subtraction angiography

“…Evaluation of axial and cross-sectional images is critical in grading the severity of stenotic disease in patients with diabetes and chronic renal failure due to extensive calcifications, which can often make standard reconstructive views deceptive. 7,11,21 Radiologists are familiar with cross-sectional images, and with appropriate window adjustment it is possible to evaluate the patency and degree of stenosis even in small calcified tibial vessels.…”

“…All segments that were adequately evaluated with both techniques were included in the comparative analysis. Analysis of steno occlusive disease was performed using a lesion-based approach rather than an arterial segment-based approach, as has been used in other studies (6)(7)(8) (homogeneity analysis) was used between MDCTA and DSA measurement, and the probability of type I error was set at 0.05. Calculations of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the detection of the degree of all stenotic lesions were made by using DSA findings as the reference standard.…”

Critical limb ischemia: an update for interventional radiologists

“…CT angiography scans are now largely done with the aid of the multi detector-row computed tomography (MDCT) technique, with sensitivities and specificities ranging from 90%-99% (23). Additionally, helical acquisition MDCT allows for better calculation of blood velocities and can produce extremely accurate images with high resolution 128-slice 3D reconstruction (24).…”

Dual-Energy CTA in Patients with Symptomatic Peripheral Arterial Occlusive Disease: Study of Diagnostic Accuracy and Impeding Factors

“…The two observers had sensitivities of 98.0 % and 93.9 % and specificities of 75.0 % and 66.7 % for detecting stenoses of > 50 % of the lower extremity arteries. Two other comparable studies have been published with smaller collectives, in which DE-CTA was evaluated in comparison to DSA [12,13]: In the study of Brockmann et al, almost equivalent sensitivity of 97.2 % was achieved. The reported specificity of 94.1 % was higher than that of the readers of our study.…”

“…Several studies have given recommendations for optimal contrast material concentration, amount, and injection rate as well as CT acquisition parameters that lead to improved, artifactdeprived image quality [19,20]. In our study, rather low volumes of contrast agent were applied in a fixed protocol in comparison to other studies [12,21]. The DE-CTA technique allows for reduced contrast material concentrations utilizing the abundant photoelectric effect at lower tube voltages [22].…”