Purpose: To evaluate the capability of venography based on MR phase-sensitive imaging (PSI) in the visualization of internal cerebral veins (ICV) and their tributaries, and to concurrently describe their anatomical variants.
Patients and methods: A total of 100 consecutive patients underwent PSI MR examination. A minimum intensity projection image from PSI was generated and evaluated by two radiologists. Veins included in this study were ICV, thalamostriate veins (TSV), septal veins (SV), anterior caudate nucleus veins, medial atrial veins and lateral direct veins.
Results: With PSI-based venography, we clearly delineated ICV, SV, TSV, anterior caudate nucleus veins, medial atrial veins and lateral direct veins in 100, 98.5, 100, 92.5, 92 and 32% of 200 sides, respectively, within a group of 100 patients. In 80.5% of the sides, the TSV-SV-ICV junction was located adjacent to the posterior margin of the foramen of Monro; in 19.5% the junction was located beyond the foramen of Monro; and in 70.8%, the anterior caudate nucleus veins drained into TSV. In 21.6% of the sides, the SV, TSV and anterior caudate nucleus veins joined together to form the ICV. In 7.6% of the sides, the anterior caudate nucleus veins and TSV separately conjoined with SV or ICV. The pattern that the anterior caudate nucleus veins drain into SV or ICV is more frequent in the sides with TSV-SV-ICV in the posterior location. Of the 64 lateral direct veins, 59.4% of the sides were accompanied by an insufficient development of the TSV and 40.6% sides were normal. Enlarged direct lateral veins frequently accompany an insufficient development of TSV.
Conclusions: Phase-sensitive imaging-based venography showed its extraordinary detectability in demonstrating the anatomy and variants of ICV and their tributaries. The advantages of this technique are a relatively short examination time, and a non-invasive and contrast-free procedure. We propose that PSI-based venography may be a promising method to study the anatomy of subependymal veins, especially the tiny and tortuous ones.