Purpose
This work focuses on the validation and further development of a new MR imaging technique - BOLD venography - to improve the anatomic visualization of the cerebral venous vasculature in volunteers and in patients with venous malformations, patients suffering from multiple sclerosis, and patients with primary brain tumors or brain metastases.
Methods and Materials
THEORYThe underlying principle of the method is due to frequency shifts caused by the bulk magnetic susceptibility effect (BMS) arising from compartmentalization of paramagnetic species, such as the deoxyhemoglobin molecules in a vein. BMS effects associated with objects of simple geometry, like cylinders, spheres or disks, and homogeneous magnetic susceptibility, cint , embedded in an external medium of magnetic susceptibility, cext , have been described in detail by Springer et al. [1]. Figure 1 illustrates the BMS effects, displayed as the difference field DB =...
Results
The following images are intended to illustrate the potential of the technique. The images are also representative of the highly detailed venous vascular information that can be obtained with BOLD venography in clinical applications. The findings suggest that the smallest vessels visible on the images have a diameter of about 100-200m, as has been inferred from comparison with radiographic atlases. Figure2 shows a typical venogramof a volunteer, which was processed by using the phase mask prior to the mIP operation. The image demonstrates exquisite detail...
Conclusion
Images obtained with high-resolution BOLD venography demonstrate exquisite detail for small deep white matter veins and cortical veins in the brain. Detailed venous vascular information is obtained in clinical applications, whereas arteries are suppressed and in most cases not evident on these images.The present study aims to refine physiological issues, which are fundamental for a deepened understanding of diseased brain states. The success of this research will offer a means to study even small variations in the microvasculature throughout the lesion that could prove valuable...
References
[1] Springer CS. Physicochemical principles influencing magnetopharmaceuticals. In: NMR in physiology and biomedicine, Gillies RJ (ed.). Academic: New York, 1994;75-99.[2] Weisskoff RM, Kiihne S. MRI susceptometry: Image-based measurement of absolute susceptibility of MR contrast agents and human blood. Magn Reson Med. 1992;24:375-383.[3] Weiss Ch, Jelkmann W. Funktionen des Blutes. In Physiologie des Menschen, Schmidt RF, Thews G (eds.). Springer-Verlag: Berlin, 1997; 411-447.[4] Reichenbach JR, Venkatesan R, Schillinger DJ, Kido DK, Haacke EM. Small vessels in the human brain: MR venography with deoxyhemoglobin as an intrinsic...
Personal Information
Jrgen R. Reichenbach, Ph.D.Clemens Fitzek, M.D.Dieter Sauner, M.D.Hans-Joachim Mentzel, M.D.Werner A. Kaiser, M.D., M.S.Institute of Diagnostic and Interventional Radiology Friedrich-Schiller University Jena, Germanye-mail:
[email protected] work was supported by the ECR Research and Education Fund 2002 (Nycomed Amersham Research Fellowship Grant to J.R.R.).