Anteroposterior View of Vertebral Arteriogram (Arterial Phase with Subtraction) :

The vertebral artery ascends through the foramina transversaria of the upper six cervical vertebrae, passes behind the lateral mass of the atlas and enters the cranial cavity through the foramen magnum where it joins the opposite vertebral artery to form the basilar artery, at the inferior border of the pons. Two spinal arteries arise from the vertebral artery in the region of the medulla oblongata. The anterior spinal artery descends in front of the medulla oblongata to unite with its fellow from the opposite side. This common trunk then passes inferiorly on the anterior aspect of the spinal cord and is very important in the cord's blood supply. The posterior inferior cerebellar artery (PICA) passes around the medulla oblongata posteriorly, and then ascends behind the origins of the glossopharyngeal and vagus nerves to the lower border of the pons, where it turns downwards to pass along the inferolateral border of the fourth ventricle. It then passes under the lower lateral edge of the cerebellar tonsil and divides into a medial and lateral branch. The PICA is of considerable importance in the diagnosis of posterior fossa lesions since it shows the anatomy of the brain stem, fourth ventricle and base of cerebellum.

   Antero-posterior View of Vertebral Arteriogram (Venous Phase with Subtraction) :

The veins of the posterior fossa have played an increasingly important role in neuroradiology in the last few years, as their distinct anatomy has become more widely known. They are constant in position and their displacement is used in determining the size and shape of posterior fossa tumours. The veins are divided into three groups. The superior group consists of the precentral cerebellar vein, superior vermian veins, and posterior and lateral mesencephalic veins. These drain into the great cerebral vein. The anterior group consists of the petrosal cerebellar vein, the anterior pontomesencephalic vein, the transverse pontine veins, and several superior and inferior hemispheric veins. This group drains to the superior or inferior petrosal sinuses. The last collection of veins is the posterior group which includes some superior and inferior hemispheric veins, inferior veins of the vermis and the medial superior cerebellar veins. This group drains into the transverse sinus.

   Lateral View of Vertebral Arteriogram (Arterial Phase with Subtraction) :

The posterior inferior cerebellar artery is again seen on this view with its characteristic contour visualized. There is a wide variation in the course and distribution of this artery and occasionally it may be absent. The superior cerebellar artery arises near the termination of the basilar artery and passes laterally below the oculomotor nerve. It then passes round the cerebral peduncle to reach the superior surface of the cerebellum. It anastomoses with branches from the inferior cerebellar arteries and also gives branches to the pons, the pineal, the superior medullary velum and the tela choroidea of the third ventricle. The posterior cerebral arteries are the terminal branches of the basilar artery. They curve round the cerebral penduncles to pass through the tentorium and reach the inferior surface of the temporal lobe. Two major divisions of these arteries are the posterior temporal and internal occipital, the latter dividing again into the calcarine and parieto-occipital arteries. Note that the posterior cerebral arteries supply the visual area of the cerebral cortex.

   Lateral View of Vertebral Arteriogram (Venous Phase with Subtraction) :

The precentral cerebellar vein is small and is easily recognized on this lateral projection. It passes upwards between the superior vermis of the cerebellum and the tectum of the midbrain, across the quadrigeminal cistern, to lie dorsal to the midbrain. This is therefore an important structure as tumours in the region of the pineal, upper vermis, aqueduct and the fourth ventricle will cause characteristic displacements of its position. The vein drains into the great cerebral vein. The petrosal vein is also of considerable importance as it runs within the cerebellopontine angle and can help in the evaluation of tumours in this region.

   Selective Spinal Cord Arteriogram :

Note the arteria radicularis magna or artery of Adamkiewicz supplying the dorsolumbar cord. It usually arises from a left dorsal branch of the posterior intercostal arteries of T9-T12. It may arise at the level of T9 on the left. Therefore, beware the level of around T10 for performing aortography with pressure injection, as spinal cord damage may result.

   Orbital Venogram with Subtraction :

This technique is performed by injection of soluble contrast medium into the frontal vein, usually under local anaesthetic. A compression band is placed around the hairline to prevent reflux of contrast into the superficial skull veins. The facial veins are also occluded by pressure. In this manner, the venous system of the orbits is demonstrated. Both superior ophthalmic veins fill from this single frontal vein injection, so that it is possible to compare the two sides. The radiological diagnosis of orbital tumours depends on three main features: first, displacement of veins; second, a pathological circulation; and, third, non-filling of the superior ophthalmic vein due to compression or thrombosis. The superior ophthalmic vein is the largest of the two draining veins and is divided into three parts: the first part along the inner wall of the orbit, the second part passing posteriorly and laterally under the superior rectus muscle and above the optic nerve. The third part runs posteriorly and slightly medially to pass through the superior orbital fissure. The other draining vein of the orbit is the inferior ophthalmic vein, which begins at the venous plexus in the floor of the orbit; it drains to the cavernous sinus either separately or having previously joined the superior ophthalmic vein.

   Bronchogram of Right Lung :

The trachea bifurcates into the right and left main bronchi at the level of the sternal angle or the vertebral level of T4/T5. The right main bronchus descends at a sharper angle than the left due to the left atrium, and gives off the right upper lobe bronchus after about 2.5 cm. This bronchus then divides into the three segments of the upper lobe: apical, posterior and anterior. Note this right upper lobe bronchus is the only bronchus to arise above its accompanying pulmonary artery. The right bronchus then continues and gives off the middle lobe bronchus, which divides into two segments: lateral and medial. The apical bronchus of the lower lobe originates at the same level as the middle lobe bronchus. The right bronchus continues, forming the four basal segments: medial, anterior, lateral and posterior, of which the posterior is the largest. Note that the right main bronchus is larger than the left due to the fact that the right lung is larger than the left (60%: 40%).

   Bronchogram of Left Lung :

There are several differences between the left and right lung. On the left side there are two lobes divided by the oblique fissure. The left main bronchus is 3.5 cm in length and divides into the left upper lobe and left lower lobe bronchi. The left upper lobe bronchus bifurcates into an upper lobe proper and a lingular segment in about 80% of cases. In 20% there is a trifurcation with the anterior segmental bronchus coming between the upper lobe proper and the lingula below. The left upper lobe has four main bronchopulmonary segments: apicoposterior, anterior, superior lingular and inferior lingular. Notice that the apicoposterior bronchus quickly divides into the apical and posterior subsegments. The lingula on the left is the equivalent of the middle lobe on the right.