MR angiography of the head and neck: value of two-dimensional phase-contrast projection technique
| Autor: | G R Applegate, S L Talagala, L J Applegate |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Phase contrast microscopy law.invention Arteriovenous Malformations Vascularity law medicine Humans Radiology Nuclear Medicine and imaging Prospective Studies Projection (set theory) Head and neck Vascular Patency Observer Variation medicine.diagnostic_test business.industry Mr angiography General Medicine Cerebral Arteries Intracranial Embolism and Thrombosis Control subjects Cerebral Veins Magnetic Resonance Imaging Cerebral Angiography Cerebrovascular Disorders Angiography Radiology medicine.symptom business Superior sagittal sinus |
| Zdroj: | American Journal of Roentgenology. 159:369-374 |
| ISSN: | 1546-3141 0361-803X |
| Popis: | MR angiography is commonly performed by using two- and three-dimensional time-of-flight and three-dimensional phase-contrast techniques. These procedures require long examination times and processing of imaging data by computing maximum intensity projections. Two-dimensional phase-contrast projection angiography has neither of these disadvantages. We analyzed the value of this technique for head and neck MR angiography in 84 patients and 15 control subjects. Patients were examined to resolve specific clinical questions such as the presence of arteriovenous malformations (20 cases), patency of carotid and vertebral arteries (35 cases), patency of the superior sagittal sinus (14 cases), patency of saphenous vein bypass grafts (11 cases), and vascularity of masses (four cases). Conventional angiograms were available for correlation in 22 patients. Two-dimensional phase-contrast projection angiograms were generated by using a gradient-recalled-echo sequence sensitized to flow with the use of flow-encoding gradients. Projection MR angiograms were obtained in approximately 3.5 min by combining images obtained with flow-encoding gradients applied along the axes defining the image plane. MR angiograms were subjectively evaluated by three observers without reference to routine MR images or conventional angiograms. High-quality studies were obtained in 93% of control subjects and 90% of patients examined. The findings based on phase-contrast angiography were confirmed with conventional angiography in 21 of 22 patients for whom conventional angiograms were available. Evaluation of vascular grafts and of the patency of major cranial vessels was easily done with two-dimensional phase-contrast angiography and was useful in postoperative follow-up examinations. We also advocate its use for superior sagittal sinus thrombosis and follow-up examinations in patients with arteriovenous malformations. |
| Databáze: | OpenAIRE |
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