![]() A total of 80 mL Isovue 350 were injected at a rate of 4.0 to 4.5 mL/s, with a 17-second delay or the use of Smart Prep at the pulmonary artery. Intravenous access was via an antecubital vein by using an 18-or 20-gauge angiocatheter. The CTA images were obtained from the C6 level to skull vertex by helical HS mode at 0.9 mm slice thickness, 0.5 pitch, 22 cm FOV and 512 × 512 matrix and 0.43 mm voxels (120 kVp, 350 mA). GE and Philips Medical Systems were used for the CTA examinations. IDX IMAGECAST FULLExaminations were excluded because of inadequate coverage and/or technical errors precluding full evaluation of the cervical carotid arteries. Examinations were not included if the purpose of imaging was due to trauma, dissection, vascular anomaly/malformation, tumor evaluation, or primary evaluation of the posterior circulation. Examinations from 29 patients (16 males, 13 females, median age of 65) with known carotid artery stenotic disease that received CT angiography studies followed by CA were entered into the study. Nevertheless, to our knowledge this is the first literature work evaluating the exact relationship between CTA and CA measurement at the stenotic segment hypothesizing distensibility induced underestimation of the degree of stenosis secondary to hand injection induced vascular distensibility on CA.Įxaminations were retrospectively collected from a single institution from August 2010 through October 2014 after IRB approval and HIPAA compliance no patient consent was required. A number of publications compared the percent carotid stenosis between CTA and CA, quantified the degree of stenosis according to the NASCET criteria on CTA and evaluated the relation between the volume of calcification in the mural plaques and the degree of vascular stenosis. , where Q = Flow, ΔP = Pressure loss, π = Mathematical constant Pi, r = Radius of pipe, μ = Dynamic viscosity and L = Length of pipe). However, the iatrogenic hand injection of contrast material on conventional angiography is expected to distend the vessel beyond what is expected under physiologic conditions secondary to the increase in pressure according to the Hagen-Poiseuille equation ( The decreased carotid distensibility in carotid atherosclerotic disease is expected to affect the blood flow and blood volume under normal physiologic condition, which is the case on CT angiography. The same observations applied to the coronary arteries can be applied to the carotid arteries in the neck. Functional impairment of the arterial wall may occur earlier than the structural abnormalities of the vessel wall. Mural plaque calcium does not affect the degree of stenosis on CTA.Īrterial Distensibility, Carotid Stenosis, Catheter Angiogramĭecreased arterial distensibility of a diseased vessel as a risk factor for coronary vascular disease (CVD) is well studied in the cardiology literature. ![]() Conclusions: There is insufficient evidence to suggest that intra-arterial hand-injection contributes to vessel distention and underestimation of percent stenosis during CA in this study. The difference in lumen diameter did not depend on our calcium grading (p = 0.484). Percentage stenosis using the NASCET criteria differed between the 3 measurements, post hoc analysis showed significant difference between CA and axial CTA (p 0.99). There is insufficient evidence that intra-arterial hand-injection during CA leads to underestimation of the degree of stenosis. Results: Accounting for repeated measurements, the likelihood that the lumen diameter from CA will be larger than CTA was higher at stenosis than distal to it but the difference in lumen diameters at stenosis was similar to CTA. Mural plaque calcium content was graded on axial CTAs. Curved sagittal MPRs mirroring the carotid artery on CA were used to measure the diameter at stenosis and at the distal lumen. CA and CTA were obtained for each patient. Methods: CA and CTA of the carotid artery from 29 patients were retrospectively studied. Purpose: During catheter angiogram (CA) there is momentary increase in intravascular volume and pressure due to intra-arterial injection that can potentially cause vascular distention at the stenotic site, whereas on CT angiogram (CTA) is unlikely due to intravenous administration. Received: SeptemAccepted: NovemPublished: November 30, 2017 IDX IMAGECAST LICENSEThis work is licensed under the Creative Commons Attribution International License (CC BY 4.0). ![]() ![]() Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USAĬopyright © 2017 by authors and Scientific Research Publishing Inc. ![]()
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