Abstract:
HTML
Purpose: To compare the individual results of CTAngiography (CTA) in the
assessment of extracranial carotid stenosis in order to better know the utility
of CTA in this indication, in association with Doppler Ultrasound (DUS) and
Magnetic Resonance Angiography (MRA).
Methods and Materials: In a prospective multicentric trial (CARMEDAS), 118
patients (96 M and 22 F ; age range 46-94) were examined for a suspected
carotid artery stenosis over a period of 20 months. The inclusion criteria was
given by DUS performed in each center by a referent physician. The clinical
status was checked by a neurologist for each patient and each carotid artery.
Among the 236 carotid analyzed, 37 were symptomatic and 193 were asymptomatic ;
2 patients were excluded and the neurological status remained unclear in one
patient. All patients underwent contrast enhanced-MRA, MRA of intracranial
arteries, MRI of the brain and multislices-CTA for the measurement of the
carotid stenosis. A centralized and blinded reading of all CTA was performed
with 3 readers (2 seniors and 1 junior in vascular radiology). The estimation
of the stenosis, using the NASCET criterias, was made on a workstation Theralys
with Multiplanar Reconstructions in the three planes and Volume Rendering
Technique. For estimation of the stenosis 7 grades were used : < 50 %, 50-59
%, 60-69 %, 70-79 %, 80-89 %, 90-99 % and occlusion. A Kappa analysis was
performed.
Results: With a threshold of 50 % (degree of stenosis, NASCET) for the symptomatic
carotid arteries and of 60 % for the asymptomatic carotid arteries, the
interobservers agreements are : Kappa 0.68 between the 2 seniors and
respectively 0.60 and 0.46 between seniors and junior. With a threshold of 80 %
for asymptomatic carotid arteries the interobserver agreement is very good for
seniors (Kappa 0.85), better between one senior and junior (0.77) and remains
mild between the second senior and junior (0.48).
Conclusion: The interobservers agreement of CTA in the assessment of carotid
stenosis is good or very good for senior radiologists trained in vascular
radiology. The experience and the knowledge of various reconstructions
modalities are crucial to obtain a good result in CTA. The place of CTA in the
diagnosis of carotid stenosis must be clarified. (Study supported by a Grant -PHRC- from the French Health
Ministery)
Questions about this event email: michel.nonent@chu-brest.fr
Nonent MD, M,
Interobservers Agreement of CT Angiography in the Estimation of Carotid Artery Stenosis. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3107109.html
