Carotid artery angiography : conventional angiography vs. magnetic resonance angiography (MRA)

Abstract

When patients are admitted to St Luke's Hospital Malta with problems related to the carotid arteries, a Doppler ultrasound is carried. If any abnormality is suspected, these are referred usually for a conventional angiography for a more in depth examination of these arteries, but this examination is quite invasive since a catheter must be inserted inside the patent so that images are obtained. Being an invasive procedure conventional angiography contain a percentage of risks, but it seemed that although there are other non invasive methods by which the carotid arteries can be assessed such as magnetic resonance angiography (MRA), in Malta practitioners still tend to prefer conventional angiography. The researcher being a student in radiography asked why in Malta, invasive procedures are still being preferred over non invasive since through literature it has been reported that .MRA is giving good results and would eventually replace conventional angiography. The research was a non experimental, descriptive correlating study were 12 carotid arteries were assessed with both conventional angiography and MRA. The aims of the study were to identify any differences in image quality between the two modalities, to determine the relationship between the results obtained from both modalities and determine by means of a specific formula, the sensitivity and specificity of the MRA images From the results obtained there was an overall agreement on detecting abnormality between conventional angiography and MRA except for 2 cases were the MRA was done without contrast. It was found that the image quality of conventional angiography is higher than that of MRA in general and also MRA gave 12% underestimation on assessing stenosis. On assessing sensitivity and specificity for MRA. MRA had a sensitivity of 100°% and specificity of 100%. Although the results obtained cannot be generalized because the sample size used was small and may not represent reality, it has been observed from this study that conventional angiography still remains better that MRA in assessing abnormalities of the carotids, but if proper CEMRA examination of the carotid arteries would be done following proper protocols. MRA could be the non invasive examination that would replace conventional angiography in the near future.