Article Details

* Date : 06-08-2009 - 07:23 PM (5434 days ago), * Characters : 1747, Words : 261, Size : 1.71 Kb.

Specificity of MR Angiography as a Confirmatory Test for Carotid Artery Stenosis: is it valid?

OBJECTIVE. We believe that many studies in the literature show a falsely elevated specificity for carotid MR angiography (MRA) in the detection of high-grade stenosis. The purpose of this study was to test the hypothesis that inclusion of a substantial proportion of normal carotid arteries in a study population will falsely elevate the specificity of MRA for confirming a high-grade carotid artery stenosis.

MATERIALS AND METHODS. Seventy-seven carotid arteries were evaluated in 63 patients suspected of having a high-grade carotid stenosis, and all vessels were evaluated with contrast-enhanced MRA. Two subgroups were created, and the specificity of MRA was calculated for each group using digital subtraction angiography (DSA) as the gold standard. Group 1 included 44 vessels classified as high-grade stenosis on sonography and all were evaluated with DSA. To test our hypothesis, group 2 included the 44 carotid arteries from group 1 plus 33 carotid arteries classified as normal or minimally narrowed on sonography and MRA.

RESULTS. In group 1, the specificity of MRA for accurately confirming a high-grade stenosis was 29% for contrast-enhanced maximum-intensity-projection (MIP) images alone and 75% for contrast-enhanced axially reformatted source images as compared with DSA. When the 33 normal arteries from group 2 were added to the data set, the specificities increased to 70% and 89%, respectively.

CONCLUSION. The calculated specificity of MRA as a confirmatory test for high-grade carotid stenosis is highly dependent on the proportion of normal carotid arteries included in the calculation. Based on our results, the specificity of MRA reported in the literature has likely been overstated because of spectrum bias.

Return to Doctor's Page
Email This Doctor

To Quote this article, you should add: : All rights of Article "Specificity of MR Angiography as a Confirmatory Test for Carotid Artery Stenosis: is it valid?" belongs to Kennith Franklin LAYTON MD and it is published at SuggestADoctor.com (http://www.suggestadoctor.com) Health Articles Library. With this notice, you can quote reasonable amount of text from this article but you have to get permission from its author to republish or redistribute it fully.

Other Articles by Kennith Franklin LAYTON MD: Use Of Covered Stent Grafts İn The Extracranial Carotid Artery: Report Of Three Patients With Follow-Up Between 8 And 42 Months. Percutaneous Sacroplasty Using Ct Fluoroscopy. A Modified Vertebroplasty Approach For Spine Biopsies. Expanding The Treatment Window With Mechanical Thrombectomy İn Acute Ischemic Stroke. Transarterial Coil Embolization Of The Venous Component Of Aggressive Type 4 Dural Arteriovenous Fistulas. The Radial Artery Access Site For Interventional Neuroradiology Procedures. Bovine Aortic Arch Variant İn Humans: Clarification Of A Common Misnomer. Subsequent Vertebral Fractures After Vertebroplasty: Association With Intraosseous Clefts. Acute Vertebral Compression Fractures İn Patients With Multiple Myeloma: Evaluation Of Vertebral Body Edema Patterns On Mr Imaging And The Implications For Vertebroplasty. Vertebral Endplate Fractures: An Indicator Of The Abnormal Forces Generated İn The Spine After Vertebroplasty. Use Of The Ulnar Artery As An Alternative Access Site For Cerebral Angiography. Angioplasty Of An Idiopathic Intracranial Arterial Stenosis. Balloon-Assisted Coiling Through A 5-French System. Outcomes Of Patients Receiving Long-Term Corticosteroid Therapy Who Undergo Percutaneous Vertebroplasty. Vertebroplasty, First 1000 Levels Of A Single Center: Evaluation Of The Outcomes And Complications. Endovascular Treatment Of Epistaxis İn Patients With Hereditary Hemorrhagic Telangiectasia. Balloon-Assisted Coiling Of Intracranial Aneurysms: Evaluation Of Local Thrombus Formation And Symptomatic Thromboembolic Complications. Transorbital Puncture For The Treatment Of Cavernous Sinus Dural Arteriovenous Fistulas. Isolated Third Nerve Palsy Assocaited With A Ruptured Anterior Communicating Artery Aneurysm. Recurrent Intracranial Stenosis Induced By The Wingspan Stent: Comparison With Balloon Angioplasty Alone İn A Single Patient.