TIME-OF-FLIGHT INTRACRANIAL MR VENOGRAPHY - EVALUATION OF THE SEQUENTIAL OBLIQUE SECTION TECHNIQUE

PURPOSE: To implement a time-of-flight MR angiographic technique using the oblique acquisition of thin gradient-echo sections to evaluate th e intracranial venous system, and to assess the feasibility of applica tion of this technique in a routine clinical setting. METHODS: The MR angiographic technique consisted of a two-dimensional gradient-echo te chnique with sequential overlapped sections obtained with an oblique o rientation, angled from the sagittal toward the coronal plane. Paramet ers were evaluated during 41 measurements in 21 healthy volunteers wit h the section orientation varying from direct sagittal to direct coron al, followed by 64 examinations in 53 patients with an angle of obliqu ity of 15 degrees to 20 degrees from the sagittal toward the coronal p lane. Confirmation of MR venographic findings was through correlation with clinical data and imaging studies. RESULTS: The Volunteer data de monstrated optimal visibility of the smaller midline structures with a n angle of obliquity of 15 degrees or greater. Patient examinations wi th this angle demonstrated sinus obstruction or thrombosis (n = 11), s inus compression (n = 2), and apparent sinus stenosis (n = 1). CONCLUS IONS: Oblique-acquisition time-of-flight MR venography seems to provid e a rapid, robust technique for intracranial Venous examination and ca n be applied as a useful adjunct to parenchymal MR in the evaluation o f suspected venoocclusive disease. This oblique technique demonstrated improved vessel contrast over direct sagittal acquisition, required s ignificantly fewer sections and thus a shorter acquisition time than d irect coronal acquisition, and was applied without difficulty in the v ast majority of patients in the clinical setting.