Accuracy of multislice CT angiography for the assessment of in-stent restenoses in the iliac arteries at reduced dose: a phantom study

Abstract

Objective: We investigated the potential of low-dose CT angiography for accurate assessment of in-stent restenoses (ISRs) of the iliac artery. Method: A Rando anthropomorphic phantom (Alderson Research Labs, Stanford, CA), custom-made wax simulating hyperplastic tissue and a nitinol stent were used to simulate a patient with clinically relevant iliac artery ISRs. The cylindrical lumen was filled with a solution of iodine contrast medium diluted in saline, representing a patient's blood during CT angiography. The phantom was subjected to standard-and low-dose angiographic exposures using a modern multidetector (MD) CT scanner. The percentage of ISR was determined using the profile along a line normal to the lumen axis on reconstructed images of 2 and 5 mm slice thickness. Percentage ISRs derived using the standard-and low-dose protocols were compared. In a preliminary study, seven patients with stents were subjected to standard-and low-dose MDCT angiography during followup. The resulting images were assessed and compared by two experienced radiologists. Results: The accuracy in measuring the percentage ISR was found to be better than 12% for all simulated stenoses. The differences between percentage ISRs measured on images obtained at 120 kVp/160 mAs and 80 kVp/80 mAs were below 6%. Patient image sets acquired using low-exposure factors were judged to be of satisfactory diagnostic quality. The assessment of ISR did not differ significantly between image sets acquired using the standard factors and those acquired using the low-exposure factors, although the mean reduction in patient effective dose was 48%. Conclusion: A reduction in exposure factors during MDCT angiography of the iliac artery is possible without affecting the accuracy in the determination of ISRs.

Extracellular Volume Fractions in Chronic Myocardial Infarction

“…31 Because of technical limitations, the density of calcified plaques was limited to 1000 HU compared with in vivo values ranging up to 1900 HU. 31 Compared with Perisinakis et al, 22 not only circular in-stent stenosis but also more complex stenoses with inhomogeneous plaques were simulated.…”

Dual-Source CT Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

“…A recent study shows the feasibility of a low-dose protocol for detecting in-stent restenoses of iliac artery stents [25]. …”

“…The effect of high pitch protocols on coronary artery stent imaging has been investigated [ 24 ]; results for iliac artery stents remain to be published. A recent study shows the feasibility of a low-dose protocol for detecting in-stent restenoses of iliac artery stents [ 25 ].…”

Diagnostic Accuracy of Multi-Detector CT Angiography in Evaluation of Lower Limb Arterial Diseases : Comparative Study with Conventional Angiography

“…Perisinakis et al (11) stated that the use of 16-slice MDCT systems or higher has increasingly gained approval of the radiology community as a valuable non-invasive alternative to conventional angiography for the follow-up of stents in lower limb arteries.…”