Purpose: The aim of this study was to investigate the visualization of small venous vessels in the normal human brain at a field strength of 3 Tesla.
Methods: T2*-weighted, three-dimensional gradient-echo images were acquired by exploiting the magnetic susceptibility difference between oxygenated and deoxygenated hemoglobin in the vasculature and microvasculature. The spatial resolution was 0.5 × 0.5 × 1 mm3, and sequence parameters were varied to obtain good vessel delineation. Improved visibility of venous vessels was obtained by creating phase mask images from the magnetic resonance phase images and multiplying these by the magnitude images. Venograms were created by performing a minimum intensity projection over targeted volumes.
Results: Highly detailed visualization of venous structures deep in the brain and in the superficial cortical areas were obtained without administration of an exogenous contrast agent; compared with similar studies performed at 1.5 T, the echo time could be reduced from typically 40–50 ms to 17–28 ms.
Conclusion: Imaging at high-field strength offers the possibility of improved resolution and the delineation of smaller vessels compared with lower field strengths.
Institut für Diagnostische und Interventionelle Radiologie (J. R. Reichenbach, W. A. Kaiser), Friedrich-Schiller-Universität, Jena, Germany, Section of Osteology (M. Barth), Department of Radiodiagnostics, University of Vienna, Vienna, Austria, The Magnetic Resonance Imaging Institute for Biomedical Research (E. Mark Haacke), St. Louis, MO, U.S.A., and Arbeitsgruppe-NMR (M. Klarhöfer, E. Moser), Institut für Medizinische Physik, Universität Wien, Vienna, Austria.
Address correspondence and reprint requests to Dr. J. R. Reichenbach, Institut für Diagnostische und Interventionelle Radiologie, Abteilung Magnetresonanztomographie, Klinikum der Friedrich-Schiller-Universität Jena, Philosophenweg 3, 07743 Jena, Germany. E-mail: firstname.lastname@example.org