MRI brain trauma Flashcards
(21 cards)
What is the primary advantage of CT in diagnosing traumatic brain injuries?
CT is quick and highly accurate in diagnosing fractures, intracranial hemorrhage, brain swelling, and brain herniation.
When is MRI indicated for traumatic brain injuries?
MRI is indicated when CT fails to explain neurologic findings and is preferred for subacute and chronic TBI.
What does FLAIR MRI sequence improve the detection of?
FLAIR improves detection of brain contusions, white matter shearing/diffuse axonal injuries, and subarachnoid hemorrhage.
What does GRE/T2* MRI sequence detect?
GRE/T2* detects blood degradation products and may help evaluate bony structures.
Which MRI sequences are superior for evaluating bony structures?
T1, PD, and/or 3D T1 sequences are superior for evaluating bony structures.
What does STIR MRI sequence identify?
STIR identifies extracranial soft tissue trauma.
Define epidural hematomas.
Epidural hematomas are a space between the inner surface of the skull and dura mater, caused by laceration or tearing of meningeal arteries.
What are the MRI findings for epidural hematomas?
Well-defined biconvex extra-axial mass of variable signal intensity that may cross dural folds but not suture lines.
What characterizes subdural hematomas?
Subdural hematomas occur in the space between pia-arachnoid and dura mater due to tearing of veins.
What are the MRI findings for subdural hematomas?
Peripheral crescent-shaped collection of hemorrhage of variable intensity that may cross suture lines but is limited by falx and tentorium.
What does subarachnoid and ventricular hemorrhage involve?
Bleeding into the CSF subarachnoid space and ventricular system due to rupture of small vessels.
What are the acute MRI findings for subarachnoid hemorrhage?
In acute cases, there may be no abnormal findings as acute hemorrhage is isointense to CSF.
What characterizes brain contusions on MRI?
Ill-defined intra-axial lesions close to the brain surface that may show T2 hyperintensity if edema predominates.
What is diffuse axonal injury caused by?
Diffuse axonal injury results from rapid acceleration head trauma causing shearing injuries.
What are expected MRI findings for diffuse axonal injury?
Hemorrhagic acute lesions, small petechial hemorrhages at gray-white matter junction, best seen on T2*.
What are signs of chronic secondary injury in the brain?
Brain atrophy and gliosis manifesting as T2 and FLAIR hyperintense parenchymal lesions.
What may cause post-traumatic brain ischemia and infarction?
It may occur due to diffuse increased intracranial pressure or focal compressive lesions.
What are the MRI findings suggestive of meningitis?
Meningeal thickening and strong contrast enhancement.
What is tension pneumocephalus?
Tension pneumocephalus is an intracranial accumulation of air that is rapidly progressive and life-threatening.
What are MRI findings for chronic secondary injury in hydrocephalus?
Ventricular dilation of variable severity and focal or multifocal brain parenchymal defects filled with CSF.
What are negative prognostic indicators on MRI for head trauma?
- Degree of midline shift
- Extent of intraparenchymal lesions
- Brain herniation
- Skull fractures
