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[Contrast-enhanced MRA of the carotid arteries using 0.5 Tesla: comparison with selective digital angiography]
1Service d'Imagerie Médicale, Centre Hospitalier Jean Monnet, 3, avenue Robert Schuman, 88021 Epinal Cedex.
Purpose:
To assess the feasability, the imaging quality and the effectiveness of contrast-enhanced MRA (CE MRA) using a 0.5 Tesla MR unit in the evaluation of internal carotid artery (ICA) stenosis. Materials and Methods. 29 patients underwent CE MRA and selective digital substraction angiography (DSA). All data were reviewed in a blinded fashion by 2 independant observers. Imaging quality was graded as good, moderate but interpretable, and insufficient. Stenosis was graded according to the NASCET classification from grade 1 to 4, with the following thresholds:<30%,<70%,<99% and occlusion. Inter and intra- observer agreement was evaluated using the kappa index.
Results:
Imaging quality was good for 79 arteries, moderate for 24 and insufficient for 13 (k MRA=0.72 and 0.64 respectively for the right and left ICAs). Interobserver agreement was good with values for right/left ICA of 0.84/0.94, 0.72/0.74 respectively for CE-MRA and DSA. For the comparison between CE MRA and DSA, agreement was also good, with values of 0.74 and 0.64 for both readers. Sensitivity of CE MRA in the detection of hemodynamically significant stenosis (>70%) was of 0.95 and 0.94 and specifity of 0.91 and 0.89 respectively for reader n degrees 1 and reader n degrees 2.
Conclusion:
CE MRA using a 0.5T MR unit is a valuable technique in the evaluation of ICA stenosis.
Insights
Contrast-enhanced MRA (CE MRA) using a 0.5 Tesla MR unit effectively evaluates internal carotid artery (ICA) stenosis. This imaging technique demonstrates good feasibility, quality, and diagnostic accuracy compared to digital subtraction angiography.
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Imaging
Background:
- Internal carotid artery (ICA) stenosis is a significant risk factor for stroke.
- Accurate non-invasive imaging is crucial for assessing ICA stenosis.
- Contrast-enhanced Magnetic Resonance Angiography (CE MRA) offers potential for evaluating carotid arteries.
Purpose of the Study:
- To evaluate the feasibility, imaging quality, and effectiveness of CE MRA using a 0.5 Tesla (T) MR unit for diagnosing ICA stenosis.
- To compare CE MRA findings with selective digital subtraction angiography (DSA).
- To assess inter- and intra-observer agreement for CE MRA in grading ICA stenosis.
Main Methods:
- 29 patients with suspected ICA stenosis underwent both CE MRA and DSA.
- Imaging quality was graded (good, moderate, insufficient).
- Stenosis was graded using NASCET classification; inter- and intra-observer agreement was assessed using kappa index.
Main Results:
- CE MRA demonstrated good imaging quality for 79 arteries.
- High inter-observer agreement was observed for CE MRA (kappa values up to 0.94).
- CE MRA showed high sensitivity (0.95) and specificity (0.91) for detecting hemodynamically significant stenosis (>70%).
Conclusions:
- CE MRA with a 0.5T MR unit is a feasible and effective technique for evaluating ICA stenosis.
- The technique provides good imaging quality and diagnostic accuracy.
- CE MRA is a valuable tool for non-invasive assessment of carotid artery stenosis.