Advertisement

A comparison between NASCET and ECST methods in the study of carotids

Evaluation using Multi-Detector-Row CT angiography

      Abstract

      Purpose

      NASCET and ECST systems to quantify carotid artery stenosis use percent diameter ratios from conventional angiography. With the use of Multi-Detector-Row CT scanners it is possible to easily measure plaque area and residual lumen in order to calculate carotid stenosis degree. Our purpose was to compare NASCET and ECST techniques in the measurement of carotid stenosis degree by using MDCTA.

      Methods and material

      From February 2007 to October 2007, 83 non-consecutive patients (68 males; 15 females) were studied using Multi-Detector-Row CT. Each patient was assessed by two experienced radiologists for stenosis degree by using both NASCET and ECST methods. Statistic analysis was performed to determine the entity of correlation (method of Pearson) between NASCET and ECST. The Cohen kappa test and Bland–Altman analysis were applied to assess the level of inter- and intra-observer agreement.

      Results

      The correlation Pearson coefficient between NASCET and ECST was 0.962 (p < 0.01). Intra-observer agreement in the NASCET evaluation, by using Cohen statistic was 0.844 and 0.825. Intra-observer agreement in the ECST evaluation was 0.871 and 0.836. Inter-observer agreement in the NASCET and ECTS were 0.822 and 0.834, respectively. Agreement analysis by using Bland–Altman plots showed a good intra-\inter-observer agreement for the NASCET and an optimal intra-\inter-observer agreement for the ECST.

      Conclusions

      Results of our study suggest that NASCET and ECST methods show a strength correlation according to quadratic regression. Intra-observer agreement results high for both NASCET and ECST.

      Keywords

      To read this article in full you will need to make a payment

      References

        • Thom T.
        • Haase N.
        • Rosamond W.
        • Rosamond W.
        • Howard V.J.
        • Rumsfeld J.
        • et al.
        American heart association statistics committee and stroke statistics subcommitee. Heart disease and stroke statistics—2006 update a report from the American heart association statistics committee and stroke statistics subcommittee.
        Circulation. 2006; 113: 85-151
        • Takaya N.
        • Yuan C.
        • Chu B.
        • Saam T.
        • Polissar N.L.
        • Jarvik G.P.
        • et al.
        Presence of intraplaque hemorrhage stimulates progression of carotid atherosclerotic plaques: a high-resolution magnetic resonance imaging study.
        Circulation. 2005; 111: 2768-2775
        • Nandalur K.R.
        • Baskurt E.
        • Hagspiel K.
        • Douglas Philips C.
        • Kramer C.M.
        Calcified Carotid Atherosclerotic plaque is associated less with ischemic symptoms than is non calcified plaque on MDTC.
        Am J Roentgenol. 2005; 184: 295-298
        • North American Symptomatic Carotid Endarterectomy Trial Collaborators
        Beneficial effect of carotid endarterectomy in symptomatic patients high with grade stenosis.
        N Engl J Med. 1991; 325: 445-453
        • European Carotid Surgery Trialists’ Collaborative Group
        Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST).
        Lancet. 1998; 351: 1379-1387
        • Saba L.
        • Caddeo G.
        • Sanfilippo R.
        • Montisci R.
        • Mallarini G.
        CT and US in the study of ulcerated carotid plaque compared with surgical results. Advantages of multi-detector-row CT angiography.
        AJNR Am J Neuroradiol. 2007; 28: 1061-1066
        • Rothwell P.M.
        • Gibson R.
        • Warlow C.P.
        Interrelation between plaque surface morphology and degree of stenosis on carotid angiograms and the risk of ischemic stroke in patients with symptomatic carotid stenosis.
        Stroke. 2000; 31: 615-621
        • Naghavi M.
        • Libby P.
        • Falk E.
        • Casscells S.W.
        • Litovsky S.
        • Rumberger J.
        • et al.
        From Vulnerable claque to vulnerable patient: a call for new definitions and risk assessment strategies. Part I.
        Circulation. 2003; 108: 1664-1672
        • Asymptomatic Carotid Atherosclerosis Group
        Endarterectomy for asymptomatic carotid artery stenosis.
        JAMA. 1995; 273: 1421-1428
        • Eliasziw M.
        • Rankin R.N.
        • Fox A.J.
        • Haynes R.B.
        • Barnett H.J.
        Accuracy and prognostic consequences of ultrasonography in identifying severe carotid artery stenosis. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group.
        Stroke. 1995; 26: 1747-1752
        • Kagawa R.
        • Moritake K.
        • Shima T.
        • Okada Y.
        Validity of B-mode ultrasonographic findings in patients undergoing carotid endarterectomy in comparison with angiographic and clinicopathologic features.
        Stroke. 1996; 27: 700-705
        • Modaresi K.B.
        • Cox T.C.
        • Summers P.E.
        • Jarosz J.M.
        • Verma H.
        • Taylor P.R.
        • et al.
        Comparison of intra-arterial digital subtraction angiography, magnetic resonance angiography and duplex ultrasonography for measuring carotid artery stenosis.
        Br J Surg. 1999; 86: 1422-1426
        • El-Saden S.M.
        • Grant E.G.
        • Hathout G.M.
        • Zimmerman P.T.
        • Cohen S.N.
        • Baker J.D.
        Imaging of the internal carotid artery: the dilemma of total versus near total occlusion.
        Radiology. 2001; 221: 301-308
        • Walker L.J.
        • Ismail Á.
        • McMeekin W.
        • Lambert D.
        • Mendelow Ad
        • Birchall D.
        Computed tomography angiography for the evaluation of carotid atherosclerotic plaque: correlation with histopathology of endarterectomy specimens.
        Stroke. 2002; 33: 977-981
        • Marks M.P.
        • Napel S.
        • Jordan J.E.
        • Enzman D.R.
        Diagnosis of carotid artery disease: preliminary experience with maximum-intensity-spiral CT angiography.
        Am J Roentgenol. 1993; 160: 1267-1271
        • Leclerc X.
        • Godefroy O.
        • Pruvo J.P.
        • Leys D.
        Computed tomographic angiography for the evaluation of carotid artery stenosis.
        Stroke. 1995; 26: 1577-1581
        • Link J.
        • Brossmann J.
        • Grabener M.
        • Mueller-Hulsbeck S.
        • Steffens J.C.
        • Brinkmann G.
        • et al.
        Spiral CT angiography and selective digital subtraction angiography of internal carotid artery stenosis.
        Am J Neuroradiol. 1996; 17: 89-94
        • Seemann M.D.
        • Englmeier K.
        • Schuhmann D.R.
        • Minx C.
        • Furst H.
        • Heuck A.
        • et al.
        Evaluation of the carotid and vertebral arteries: comparison of 3D SCTA and IA-DSA—work in progress.
        Eur Radiol. 1999; 9: 105-112
        • Cinat M.
        • Lane C.T.
        • Pham H.
        • Lee A.
        • Wilson S.E.
        • Gordon I.
        Helical CT angiography in the preoperative evaluation of carotid artery stenosis.
        J Vasc Surg. 1998; 28: 290-300
        • Saba L.
        • Mallarini G.
        MDCTA in the study of carotid plaque stenosis degree: evaluation of inter-observer agreement.
        AJR Am J Roentgenol. 2008; 190: W41-W46
        • Landis J.R.
        • Koch G.G.
        The measurement of observer agreement for categorical data.
        Biometrics. 1977; 33: 159-174
        • Bland J.M.
        • Altman D.G.
        Statistical methods for assessing agreement between two methods of clinical measurement.
        Lancet. 1986; 1: 307-310
        • Staikov I.N.
        • Arnold M.
        • Mattle H.
        • Remonda L.
        • Sturzenegger M.
        • Baumgartner R.W.
        • et al.
        Comparison of the ECST, CC, and NASCET grading methods and ultrasound for assessing carotid stenosis.
        J Neurol. 2000; 247: 681-686
        • Rothwell P.M.
        • Gibson R.J.
        • Slattery J.
        • Sellar R.J.
        • Warlow C.P.
        Equivalence of measurements of carotid stenosis: a comparison of three methods on 1001 angiograms. European Carotid Surgery Trialists Collaborative Group.
        Stroke. 1994; 25: 2435-2439
        • Donnan G.A.
        • Davis S.M.
        • Chambers B.R.
        • Gates P.C.
        Surgery for prevention of stroke.
        Lancet. 1998; 351: 1372-1373
        • Rothwell P.M.
        • Gutnikov A.
        • Warlow C.P.
        • for the European Carotid Surgery Trialists Collaborator
        Reanalysis of the final results of the European carotid surgery trial.
        Stroke. 2003; 34: 514-523
        • Gagne P.J.
        • Matchett J.
        • MacFarland D.
        • Hauer-Jensen M.
        • Barone G.W.
        • Eidt J.F.
        • et al.
        Can the NASCET technique for measuring carotid stenosis be reliably applied outside the trial?.
        J Vasc Surg. 1996; 24: 339-356
        • Vanninen R.
        • Manninen H.
        • Kovisto K.
        • Tulla H.
        • Partanen K.
        • Puranen M.
        Carotid Stenosis by digital subtraction angiography: reproducibility of the European carotid surgery trial and the North American Symptomatic Carotid Endarterectomy Trial measurement methods and visual interpretation.
        Am J Neuroradiol. 1994; 15: 1635-1641
        • Zhang Z.
        • Berg M.H.
        • Ikonen A.E.
        • Vanninen R.L.
        • Manninen H.I.
        Carotid artery stenosis: reproducibility of automated 3D CT angiography analysis method.
        Eur Radiol. 2004; 14: 665-672