Info
🌱 來自: Huppert’s Notes
Imaging🚧 施工中
Imaging
Non-contrast head computed tomography (NCHCT)
• Description: CT scanning is particularly useful for evaluation of bony defects, metallic objects, calcifications, hemorrhage, and hydrocephalus
• Common indications: Acute stroke (to exclude hemorrhage), tumor, hydrocephalus, trauma, subarachnoid hemorrhage, bony or sinus disease
• Pitfalls: Insensitive for early ischemic stroke changes and posterior fossa and spinal cord lesions, among others
Magnetic resonance imaging (MRI)
• Description: MRI does not involve ionizing radiation and provides superior soft tissue sensitivity
• Common indications: Stroke, tumor, parenchymal pathology (ischemia, demyelinating, lesions, edema, infection, etc.) of the brain or spinal cord
• Sequences:
- T1: Gray matter is gray, white matter is white, CSF is black
- T2: Gray matter is white, white matter is gray, CSF is white
- T2/FLAIR: Same as T2 except CSF is black
- Pearl: T1 is usually helpful for anatomy only. On T2, because CSF is white (water), then edema is also white, which means pathology appears bright and is typically easier to see. T2/FLAIR subtracts the bright CSF signal to make pathology even easier to appreciate