Magnetic resonance angiography, digital subtraction angiography and Doppler ultrasonography in detection of carotid artery stenosis: a comparison with findings from histological specimens
Abstract
Patients with internal carotid artery (ICA) stenosis were investigated by digital subtraction angiography (DSA), Doppler ultrasonography (DUS) and magnetic resonance angiography (MRA). Atherosclerotic plaque specimens were transversally cut into smaller segments and histologically processed.
The slides were scanned and specimens showing maximal stenosis were determined; the minimal diameter and the diameter of the whole plaque were measured. DSA, DUS and MRA measurements were obtained in 103 patients.
A comparison between preoperative and histological findings was performed. In addition, correlation coefficients were computed and tested.
Results Results show a significant correlation for each of the diagnostic procedures. Mean differences in the whole cohort between preoperative measurements and the histological measurements are as follows: angiographic measurement of carotid stenosis underestimated histological measurement by 14.5% and MRA by 0.7%, but DUS overestimated by 6.6%.
The results in severe stenosis (GREATER-THAN OR EQUAL TO70%) are as follows: angiographic measurement underestimated the histological measurements by 2.3%, but MRA overestimated by 12.1% and DUS by 11.3%. The results in moderate stenosis (50-69%): angiographic measurement underestimated the histological measurements by 12.3%, but MRA overestimated by 0.2% and DUS by 7.2%.
The results in mild stenosis (30-49%): angiographic measurement underestimated the histological measurements by 24.7% and MRA by 7.6%, but DUS overestimated by 3.3%. Conclusions Our study confirms that DSA underestimates moderate and mild ICA stenosis.
DUS slightly overestimated moderate ICA stenosis and highly overestimated high-grade ICA stenosis. MRA proved to be accurate in detecting moderate ICA stenosis, but slightly underestimated mild stenosis and overestimated high-grade stenosis..