Skull and Blood Supply to the Brain Flashcards
for radiology of the head, ____ is most commonly available; it is most commonly requested for screening in trauma (for fractures, radiopaque intracranial foreign bodies)
x-ray
materials s/a stone, cement, metal w/c are very dense
radiopaque materials
invisible in x-ray; ex: wood, glass, plastics
radiolucent materials
- for examination of brain trauma, stroke, and intracranial pathologies
- superior than MRI in detecting fractures, foreign bodies, and calcifications
- cheaper than MRI
CT scan
_____ for bones and _____ for soft tissue (new growth)
CT scan
MRI
- reserved for mass lesions
- cannot detect intracranial calcifications
- metallic foreign bodies and implants will affect imaging and cause artifacts
MRI
involves direct injection of dye and mapping of blood vessels
angiography
- Pt lying on the table; x-ray coming from the front; casette is under the table
- One of the most commonly requested projection of the skull (together w/ lateral view)
skull AP view (frontal projection)
- Side of interest/trauma should be indicated
- Pathology should be closest to the film/indicator
- Requested together w/ the skull AP
skull lateral view
- For occipital bone
2. Similar to AP view but X-ray is tangential
towne’s view (AP axial)
- For trauma or fractures to the zygomatic arch
2. Pt’s neck is hyperextended
submentovertex view (zygomatic arch)
- Technique for paranasal sinuses and facial bones
2. For examination of sinuses when suspecting sinusitis
water’s view
for paranasal sinuses, include the ____ through opened mouth
sphenoid sinus
- For injuries to the frontal bone
2. Frontal bone is in direct contact w/ the film
caldwell’s view (frontal bone)
- An interventional procedure for the dx and/or tx of intracranial pathology
- Uses a catheter, x-ray imaging guidance and an injection of contrast material to examine blood vessels in the brain for abnormalities s/a aneurysms & disease s/a atherosclerosis (plaque)
cerebral angiography
gold standard in evaluation of cerebral arteries
cerebral angiography
cerebral angiography indications
- Evaluate arteries of the head and neck before surgery
- Provide additional information on abnormalities seen on MRI or CT of the head, such as the blood supply to a tumor
- Prepare for other medical tx, s/a in the surgical removal of a tumor
- Preparation for minimally invasive tx of a vessel abnormality
CEREBRAL ANGIOGRAPHY
- Involves insertion of long catheter from ____ to the ____
- Intracranial angiography demonstrates the cerebral blood vessels by injection of radiopaque material into the circulation of the carotid and vertebral arteries
- When the roentgenographic exposure is made during or immediately after the injection of contrast medium, an ___ is obtained
- A ___ is obtained when the roentgen film is exposed 3 or 4 sec later
- Under normal conditions, only blood vessels of the injected side are visible
- Vertebral angiography is technically difficult and not often indicated
- femoral artery; carotid artery
- arteriogram
- venogram
CEREBRAL ANGIOGRAPHY INDICATIONS
- Dx and tx of ___
- Investigation of ___
- Confirming brain death
- aneurysms, acute ischemic stroke, vascular abnormalities, cerebral vangiospasms post subarachnoid hemorrhage, meningioma (preoperative embolization)
- reversible cerebral vasoconstriction syndrome; moya-moya syndrome
- Noninvasive technique that allows visualization of the internal and external carotid arteries and vertebral arteries
- Can include just the intracranial compartment or also extend down to the arch of the aorta
- Overaching goal of this examination is an optimal enhancement of the carotid arteries w/ little to no venous component
CT angiography of the cerebral arteries (CTA carotids)
CT angiography of the cerebral arteries (CTA carotids) indications
- Ischemic stroke to detect occlusion and thrombosis
- Transient ischemic attack to detect carotid artery stenosis
- Subarachnoid hemorrhage for detection of aneurysms
- Cerebral parenchymal hemorrhage to assess for the presence of a vascula malformation or ongoing bleeding (spot sign)
CT angiography of the cerebral arteries (CTA carotids) contraindications
- Previous severe rxn to iodinate
2. Non-compliance
CT angiography of the cerebral arteries (CTA carotids) advantages
- Ability not only to evaluate the vessels from their origin (aortic arch to intracranial portion), but also assess non-vascular neck structures and brain parenchyma
- Less expensive and at a low risk
CT angiography of the cerebral arteries (CTA carotids) disadvantages
- Inability to select a single vessel and the fact that it images the vessel at only one time does limit the ability to evaluate flow-related features of complex malformations
- Has lower resolution than catheter angiography, making the assessment of subtle wall changes s/a those seen in dissection or vasculitis, making it difficult to identify
- Compared to MR angiography, its main disadvantage is the need for both ionizing radiation and IV contrast