Post Treatment Surveillance

MRA is often used to evaluate patients following treatment for vascular disease. Again, the major area of evaluation is in patients with carotid atherosclerotic disease. Determination of possible restenosis after carotid endarterectomy is an indication for cervical carotid MRA. Techniques for this type of study are identical with those for pre-operative carotid vascular evaluation. Images can detect and quantify restenosis and help determine the need for further interventional therapy.

Although still largely investigational, endovas-cular treatment of carotid stenosis is becoming more accepted in recent years. A number of patients have received treatment with carotid angio-plasty without stenting. Evaluation of these patients is also similar to that of patients following carotid endarterectomy. Patients with prior carotid stent placement, however, present added problems. Safety considerations due to possible magnetic attraction of the intravascular stent must be considered. Most stents are not attracted in a magnetic field and therefore are generally safe to image. To be absolutely certain, since most often one is not aware of the exact stent type used, we generally limit MR imaging of post-stented patients for any reason to imaging only after the stent has been in place for a minimum of six weeks. This is to ensure that there is adequate scarring and endotheliaza-tion around the stent, which will help stabilize the device should there be any magnetic field attraction. In terms of evaluation for possible restenosis, local artifacts due to magnetic susceptibility from the metallic stent material may interfere to varying degrees with evaluation of the vessel lumen. In the case of significant artifact, evaluation for restenosis with MRA is impossible. CTA may then be a better alternative although this too may have difficulty due to interference with the CT visualization of the vessel lumen inside the stent. In these cases, catheter angiography may be the only viable alternative for evaluating vessel lumen status.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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