Magnetic resonance imaging

Magnetic resonance imaging (MRI) is a more sensitive imaging modality than CT but is also more expensive, more technically demanding, and more time consuming. MRI takes approximately 30 to 40 min and requires a co-operative or sedated patient. These constraints generally make MRI impractical in the acute phase of injury. Patients with moderate to severe head injury are frequently uncooperative and require intubation and ventilatory support, making it impossible to obtain MRI scans without the availability of MRI-compatible ventilators. Despite these limitations, MRI is indicated if there is a focal neurological deficit or a prolonged period of unconsciousness not explained by CT. In addition to the conventional T1W and T2W images, other magnetic resonance techniques such as spin echo and gradient echo imaging are available for imaging brain injury. Other techniques of imaging brain injury are under investigation.

MRI is ideal for imaging diffuse axonal injury, which is characterized by multiple small focal areas of damage with increased signal intensity on T2W images. Lesions may be found in the lobar white matter, the corpus callosum, the dorsolateral brainstem, and the internal capsule. MRI is also more sensitive than CT in identifying hemorrhagic and non-hemorrhagic cortical contusions. Another advantage of MRI is its ability to image soft tissue at the skull base and posterior fossa. Imaging brainstem injury is particularly important in patients with prolonged loss of consciousness not explained by CT. In these cases MRI frequently demonstrates shear injury.

Sleep Apnea

Sleep Apnea

Have You Been Told Over And Over Again That You Snore A Lot, But You Choose To Ignore It? Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air?

Get My Free Ebook


Post a comment