Fig 1.
3D rendering of magnetic resonance angiography acquisition of the rostral part of the mouse head.
The mouse head is seen from above (the back of the head has been removed in post-processing). The anterior confluence of the median olfactory sinus (thin arrow) with the paired rostral rhinal veins (arrowhead) and the beginning of the superior sagittal sinus (thick arrow) is shown. Extracranially the supraorbital vein is visible.
Fig 2.
Axial silicon-microcomputed tomography of the rostral rhinal vein.
(A-D) Four consecutive axial silicon- microcomputed tomography slices in cranio-caudal sequence showing the drainage of each rostral rhinal vein, which, after an intraosseus course, joins with the ipsilateral superficial temporal vein, through the frontal foramen.
Fig 3.
3D rendering of magnetic resonance angiography acquisition of the mouse head.
3D rendering of magnetic resonance angiography acquisition of the caudal part of the mouse head, as seen laterally from a postero-superior angle. The confluence of the left caudal rhinal vein with the ipsilateral transverse sinus, as well as the junction of the superior petrosus sinus, are shown.
Fig 4.
Single axial magnetic resonance angiography partition and 3D rendering of mouse head.
(A)Single axial magnetic resonance angiography partition at the mid-level of the brain hemispheres ((B) mid-sagittal T2w slice used as a reference) and (C) 3D rendering of magnetic resonance angiography acquisition of a mouse head, as seen from above, The position of the superior sagittal sinus and inferior sagittal sinus is clearly shown as well as the connections of the former on the dorsal surface of the brain.
Fig 5.
Magnetic resonance angiography and 3D of the caudal part of confluence of sinuses, and the deep brain venous system.
(A) Maximum Intensity Projection of axial magnetic resonance angiography partitions at the mid-level of the brain hemispheres ((B)mid-sagittal T2w slice used as a reference,) and 3D rendering of magnetic resonance angiography acquisition of the caudal part of a mouse head, ((C)lateral view; (D) view from above), The confluence of sinuses, and the deep brain venous system (internal cerebral veins, Galeno vein, straight sinus, inferior sagittal sinus) can be easily appreciated as it resembles the configuration in humans.
Fig 6.
Magnetic resonance angiography with 3D of the confluence of sinuses and connections of the transverse sinuses.
(A) Maximum Intensity Projection of axial Magnetic resonance angiography partitions, (B) at the occipito-cerebellar border (mid-sagittal T2w slice used as a reference), and (C) 3D rendering of magnetic resonance angiography acquisition of that region as seen from above. The confluence of sinuses and the connections of the Transverse sinuses are depicted.
Fig 7.
Magnetic resonance angiography of the transverse sinus.
(A), (B), Single axial magnetic resonance angiography partitions at two levels showing (A) the tributaries of the transverse sinus and its lateral bifurcation into the straight sinus and (B) petrosquamosal sinus.
Fig 8.
Magnetic resonance angiography with 3D rendering and silicon-computed tomography angiography of the petrosquamosal fissure.
Upper row: Maximum Intensity Projection of axial magnetic resonance angiography partitions (slab at the occipito-cerebellar border (B) mid-sagittal T2w slice used as a reference,) and 3D rendering of silicon-enhanced computed tomography angiography as seen from (C) inside and (D) outside of the skull. (E), (F), (G) Lower row: Axial computed tomography slices in caudo-cranial sequence showing the exit from the brain of most of the transverse sinus blood through the petrosquamosal fissure (arrows), then joining the external jugular system.
Fig 9.
3D magnetic resonance angiography of external jugular vein.
3D magnetic resonance angiography rendering of the extracranial vasculature as seen (A) in a frontal-inferior view and (B) in a lateral view. The main facial venous trunks are well-shown, running caudally to join together to form the external jugular vein.
Fig 10.
Magnetic resonance angiography with 3D rendering acquisition of the orbital region.
Upper row: (A) axial and (B) coronal computed tomography slice. Lower row: 3D rendering of magnetic resonance angiography acquisition of the left orbital region ((C) antero-lateral view,). 3D rendering of silicon-enhanced computed tomography angiography ((D)lateral view,).(A), (B),The large retro-orbital venous plexus (white arrow) is clearly visible as well its drainage into the posterior facial vein ((C), (D) white arrow).(D)The superficial temporal vein is also shown in.
Fig 11.
Axial computed tomography of the middle cranial fossa.
Axial computed tomography slices at the level of the middle cranial fossa of the basicranium; (A) = 1mm-thick “MIP-ped” slab; (B)-(I) consecutive 0.05mm-thick slices in a cranio-caudal sequence showing the confluence of small vessels in the hypothalamic region (B), (C), (D) toward a large intraosseus median inter-cavernous sinus (E), (F) which bilaterally exits the brain (G), (H) to join the external jugular vein system (arrow in (I)).
Fig 12.
Magnetic resonance angiography with 3D rendering of the neck vessels.
3D rendering of the magnetic resonance angiography acquisition of the neck vessels (right anterior oblique view), showing the external jugular vein, the internal jugular vein and the common carotid artery.
Fig 13.
Eco-color Doppler examination.
Craniocaudal scans performed with transverse planes of the upper and middle third of the mouse neck. (A) At the level of the upper third of the neck the external carotid artery runs anteriorly. (B-D) At level of middle third of the neck arterial and venous vessels are detectable. (B) The blood flow of anterior jugular veins is directed toward the external jugular veins. (C-D) The internal jugular veins are thin and in the typical position, anteriorly and laterally to the carotid artery.
Fig 14.
Magnetic resonance angiography of the internal jugular veins.
Axial magnetic resonance angiography partitions at the level of the posterior cranial fossa showing some tributaries (e.g. cerebellar veins) of the internal jugular veins, which, differently from humans, is clearly hypotrophic in respect to the external jugular vein.
Fig 15.
Magnetic resonance angiography of the lower part of the cerebellum and occipital plexus.
(A) Single axial Magnetic resonance angiography partition at the level of the lower part of the cerebellum ((B) mid-sagittal T2w slice used as a reference) showing the occipital plexus. V: External Jugular Vein, IJV: Internal Jugular Vein, CA: Carotid Artery.
Fig 16.
Magnetic resonance angiography of external jugular vein and internal jugular vein with size measurements.
(B) Single axial magnetic resonance angiography partition at the middle level of the neck ((A) mid-sagittal T2w slice used as a reference,) showing the relative size (area, diameter, etc) of the external jugular vein and internal jugular vein.
Fig 17.
Eco-color doppler with pulsed doppler analysis of veins.
(A)The internal jugular vein waveform is characterized by a monophasic pattern and low pulsatility index. (B)The external jugular vein is characterized by three-phasic pattern with high pulsatility. (C) In the small inset on the left the spectral analysis of the carotid artery blood flow is shown.
Fig 18.
Eco-Color Doppler of vein collaterals.
Collateral vein that connect external jugular vein and vertebral plexus. The flow is directed from vertebral plexus to the right external jugular vein.
Fig 19.
Cerebral areas with different venous drainage.
Brain areas can be identified and divided according to the dominant venous drainage. The olfactory bulbs and frontal and parieto-temporal lobes drain mainly in the external jugular veins. The occipital lobe and cerebellum drain mainly in the internal jugular veins (modified from Dorr 2007 [27]).