The use of ultrasound to characterize neurologic conditions in critically ill patients offers a unique window into cerebral physiology. Whether it is imaging the optic nerve sheath as a surrogate of intra-cranial pressure, trans-cranial Doppler for cerebrovascular arrest, or B-mode ultrasonography for midline shift, ultrasound offers a look into the brain that the clinical exam may not offer.

This section will explore the use of neurological ultrasound to explore pathophysiology and hemodynamics to explore a variety of clinical problems. While we will discuss these techniques in the context of critical illness, they are as applicable in a cross section of patients in the emergency department, operating room, or even in flight.