Zampieri and colleagues from Brazil report the use of brain ultrasound in two ICU patients who had had hemicraniectomies.
One of the patients had a subarachnoid haemorrhage with hydrocephalus and an infarct due to vasospasm requiring hemicraniectomy, who subsequently deteriorated with decreasing ventricular catheter drainage, raising suspicion of acute hydrocephalus. Brain ultrasonography confirmed moderate hydrocephalus which was seen to improve after catheter desobstruction.

The authors note: ‘standard ultrasonography can be performed through a hemicraniectomy field and may be helpful in a small group of patients. Since decompressive hemicraniectomy is increasingly being used in critical care medicine, bedside evaluation of the brain using the hemicraniectomy as an insonation window could be useful as a noninvasive triage tool and reduce the need for patient transport to the imaging center.’
Use of ultrasonography in hemicraniectomized patients: a report of two cases
Intensive Care Med. 2010 Dec;36(12):2161-2
Not got a hole in the skull? Could try a bony ultrasound window – compare the clear scans above with this scan of an extradural haematoma