Doenças Neurovasculares

Prévia do material em texto

27/02/2016 
1 
 
A. Glioma 
B. AVM 
C. Infarct 
D. Meningioma 
27/02/2016 
2 
 CT findings 
 Vascular tangles are serpiginous and hyperdense 
without contrast from the blood pool effect. 
 AVMs may contain punctate or curvilinear 
calcification. 
 AVMs will enhance 
 
 
Unenhanced and enhanced axial CTs of brain 
shows a large, serpiginous AVM adjacent to 
the tentorium 
 
 A. Right parietal mass 
 B. Acute subdural hematoma 
 C. Chronic intraparenchymal hemorrhage 
 D. Subacute subdural hematoma 
 Findings: Axial CT scan demonstrates that there is a large R 
parietal subdural hematoma isodense to the brain. There is 
associated mass effect with effacement of the right lateral 
ventricle. Enhanced images delineate the exact margins of the 
hemorrhage. 
 Acute hemorrhage on CT scan appears as bright on CT scan. Over 
a period of time, the blood becomes darker. Attenuation 
decreases by 1.5 HU per day on average. There is a point when 
the blood becomes isodense to the brain parenchyma. 
 Contrast enhancement can help separate the clot and brain 
parenchyma since there is enhancement of displaced cortical 
vessels. 
 Subdural hematomas are usually crescentic shaped and have the 
capability of crossing the cranial sutures. 
 The etiology of a subdural hemorrhage occurs from a tearing of 
the bridging veins in the subdural space. 
 Subdural hematomas can be lethal with mortality rates ranging 
from 50-85%. 
27/02/2016 
3 
 36 year-old with severe headache 
 
A. Epidural hematoma 
B. Subdural hematoma 
C. Glioblastoma multiforme 
D. Diffuse axonal injury 
E. Subarachnoid hemorrhage 
 Bleeding into the subarachnoid space, 
between the pia mater and the arachnoid 
Most commonly occurs between ages of 25 to 
65, increasing in frequency with age 
Most common causes are rupture of an 
intracranial aneurysm or head trauma 
 
 Unenhanced CT of the brain is the study of choice for establishing presence of SAH 
 Acute hemorrhage is most evident 2-3 days after the acute bleed 
 CT angiography and MRA have replaced conventional angiography in most 
institutions for the identification and location of the aneurysm itself 
 Acute hemorrhage appears as high-attenuation (white) material that fills the 
normally black subarachnoid spaces, which include 
 The basilar cisterns 
 Especially the suprasellar cistern 
 The sulci 
 Especially the Sylvian fissures 
 Over the convexities of the brain, SAH produces white, branching densities 
representing the normally black sulci filled with blood 
 During the subacute period (days to weeks after acute bleed), look for 
 Decreased visualization of the normally “black” fluid within the sulci and basal cisterns 
 Enlargement of the ventricles 
 From communicating hydrocephalus 
 False positives may occur by mistaking normal visualization of the falx cerebri 
and tentorium cerebelli for SAH 
 MR angiography is useful in identifying the location of aneurysms 
 Cerebral angiography is used for the detection of intracranial aneurysms 
 Such features as aneurysm size and shape can help determine which aneurysm has bled 
 Still considered the “gold” standard for diagnosis of intracranial aneurysm 
 
Subarachnoid hemorrhage 
(SAH). There is high-
attenuation blood in the 
Sylvian fissures (blue arrows) 
and the interhemispheric 
fissure (red arrow) seen on 
this non-contrast enhanced 
CT of the brain. Do not 
confuse normal, physiologic 
calcifications (white and 
black arrows) for blood. 
27/02/2016 
4 
 
A. Choroid plexus cysts 
B. Pinealomas 
C. Meningiomas 
D. Neurofibromas 
 Cyst-like spaces that occur in the choroid in 
approximately 1-6% of fetuses between 13 and 
24 weeks gestation 
 Majority are small and incidental, disappearing 
by 26 weeks gestation 
 Thought to represent entrapment of 
cerebrospinal fluid within an in-folding of 
neuroepithelium 
 
 Two images form an unenhanced axial CT of the 
brain show ring-like calcifications in the region 
of the choroid plexus representing choroid 
plexus cysts 
 
Newborn with bump on head following 
difficult delivery 
27/02/2016 
5 
A. Subgaleal hemorrhage 
B. Epidural hematoma 
C. Cephalohematoma 
D. Skull fracture 
E. Down Syndrome 
 Usually develops after delivery using instruments 
 Subperiosteal hematoma 
 No associated skull fracture 
 Limited by suture lines 
 Large cephalohematomas may occur with vitamin K 
deficiency in the newborn 
 
 Imaging Findings 
 Visible on conventional radiography as soft tissue 
subperiosteal elevation 
 Usually over parietal bones, then occipital, and lastly 
frontal 
 Sharply demarcated soft tissue density 
 Outer border may calcify as a rim 
 The skull may appear thickened at the site of the 
hematoma for years 
Cephalohematoma. On the frontal skull radiograph on the left, these is a soft 
tissue mass (white arrow) in the soft tissues of the scalp. Notice how the mass 
does not cross beyond the saggital suture line (black arrow). The lateral view 
shows the soft tissue mass is located in the parietal region (white arrow). 
 42 year-old with chronic headaches 
 
27/02/2016 
6 
Unenhanced axial CT scans of head 
T1 and T2 FLAIR MRI images of brain 
A. Normal pressure hydrocephalus 
B. Menigioma 
C. Bullet wound 
D. Metastases 
E. Colloid cyst of the 3rd ventricle 
 Benign, epithelium-lined cysts 
Most common tumor of the third ventricle 
but rare overall 
Usually found in adults in their 40s or 50s 
 Arise from anterosuperior aspect of 
3rd ventricle near the foramina of Monro 
 Cysts are usually filled with a thick mucus-
like material although some are filled with 
thinner, serous fluid 
 
CT or MRI may be used to diagnose a 
colloid cyst 
CT 
 Round mass in anterior 3rd ventricle with high 
attenuation 
 Hydrocephalus 
MRI 
 Imaging characteristics of the cyst are variable 
 Most commonly, they are hyperintense on T1 
and isointense to hypointense on T2 
 They do not enhance 
Colloid Cyst of the Third Ventricle. There is a high attenuation mass in the 
anterior aspect of the third ventricle (white arrow) causing obstruction at 
the foramina of Monro with resultant hydrocephalus, left (yellow arrow) 
frontal horn worse than right (blue arrow) on the axial CT scans (above). The 
bodies of the lateral ventricles are dilated (green arrows). 
27/02/2016 
7 
Below, the mass is hypoattenuating on T1 FLAIR image (white arrow) and 
hyperattenuating on T2 FLAIR image (yellow arrow). 
 BRANT, William E.; HELMS, Clyde A. 
(Ed.). Fundamentals of diagnostic 
radiology. Lippincott Williams & Wilkins, 
2012. 
 JUHL, John H.; CRUMMY, Andew B.; 
KUHLMAN, Janet E. Interpretação 
radiológica. Interpretação radiológica, 2000. 
 
 
GAILLARD, F. Appendicolith; Radiopaedia. 
org. 2014. 
William Herring. LEARNING RADIOLOGY, 2014