Article Figures & Data
Figures
- Fig 1.
Variations of the ASV–ICV junction and its relation to the foramen of Monro. There are a total of 5 venous angle types (IA, IB, IIA, IIB, III).3 Types I and II refer to the relation of the venous angle to the foramen of Monro (adjacent to or located behind, respectively), whereas types A and B differentiate the ASV located at the venous angle (anteriorly) or beyond it (posteriorly). In type III, the ASV is absent.
- Fig 2.
Types of ICV branching patterns. We classified ICV tributaries into 4 types with respect to the main veins draining the basal nuclei. In type 1, only the thalamostriate vein collects blood from the basal nuclei. Types 2 and 3 are characterized by the presence of a suprathalamic or retrothalamic LDV, respectively, which receives tributaries from the striatum. In type 4, the basal vein takes an unusual course and drains the basal nuclei.
- Fig 3.
CTA MIP axial cross-sections of the ICV branching patterns. A, Normal ICV anatomy (type 1) in both the left and right hemispheres. The arrow indicates the TSV; the arrowhead, the medial atrial vein. B, The suprathalamic variants of the lateral direct vein (right hemisphere). The arrow indicates the LDV. Type 1 is present in the left hemisphere. C, The retrothalamic LDV (left hemisphere). The arrow indicates the LDV. Type 1 is shown in the right hemisphere.
- Fig 4.
CTA MIP axial cross-sections of the ICV branching patterns with an LDV and an absent thalamostriate vein. Arrows indicate LDVs. A, The suprathalamic LDV (type 2; left hemisphere). B, The retrothalamic LDV (type 3; right hemisphere).
Tables
ASV Termination Type ASV Termination Total (531 ASVs) Type A Venous angle 383 72.13% Type B ICV: anterior third 76 14.31% ICV: middle third 52 9.79% ICV: posterior third 1 0.19% ICV elongation (absent TSV) 20 3.77% LDV 5 0.94% MAV 15 2.82% Cavernous sinus 1 0.19% Note:—MAV indicates medial atrial vein.
↵a Types A and B refer to the classification of ASV–ICV junction proposed by Türe et al (1997),3 and they differentiate between the ASV located at the venous angle (anteriorly) or beyond it (posteriorly).11
Branching Type LDV Termination Total (110 LDV) Type 2 (a suprathalamic LDV) ICV: anterior third 8 7.27% ICV: middle third 70 63.64% ICV: middle third, as a common stem with an MAV 2 1.82% Type 3 (a retrothalamic LDV) ICV: posterior third 18 16.36% ICV: posterior third, as a common stem with an MAV 8 7.27% Great cerebral vein 2 1.82% Note:—MAV indicates medial atrial vein.
↵a The presence of the LDV characterizes types 2 and 3 of the ICV branching patterns.
