Diffusion-Weighted Imaging in the Setting of Diffuse Cortical Laminar Necrosis and Hypoxic-Ischemic Encephalopathy

Alexander M. McKinney; Mehmet Teksam; Ross Felice; Sean O. Casey; Ronald Cranford; Charles L. Truwit; Stephen Kieffer

Article Figures & Data

Figures

Tables

Download figure
Open in new tab
Download powerpoint
Fig 1.
Patient 1. A 54-year-old comatose man experienced an episode of apnea and hypoxia during surgery, with subsequent cardiopulmonary arrest and resuscitation.
A, CT scan obtained 4–5 hours after surgery does not show any significant abnormalities and was interpreted as normal.
B, T2-weighted MR image (windowed at 700/500) obtained 48–72 hours after the hypoxic-ischemic episode illustrates mildly pronounced gray–white matter differentiation of the cerebral hemispheres and gyral swelling.
C, TurboFLAIR image (windowed at 650/400) demonstrates similar findings as those on the T2-weighted image, with mildly pronounced gray–white matter differentiation.
D, DW image with initial window/level (improper window/level of 1000/400) that is not in keeping with our usual window/level (250/150) shows that the diffuse cortical abnormality is obscured. Although improperly windowed, there is pronounced gray–white matter differentiation, not usually present on DW images (see Fig 2).
E, The abnormality is more distinct on this properly windowed DW image (windowed at 250/150), which shows diffuse uniform cortical and caudate hyperintensity with accentuation of the gray–white matter interface.
F, ADC map demonstrates severe, uniform, cortical restricted diffusion (mean ADC value, 0.31 × 10⁻³ mm²/s as measured in the perirolandic cortex in this patient) that was interpreted as cortical laminar necrosis. Electroencephalogram obtained the next day (3 days after cardiorespiratory arrest) was interpreted as electrocerebral silence, and support was withdrawn per request of the patient’s family.
Download figure
Open in new tab
Download powerpoint
Fig 2.
Patient 5. Improper versus properly windowed DW images in a patient with HIE versus a properly windowed DW image in a neurologically normal 41-year-old man; all images were obtained with the same MR system. The 41-year-old patient underwent MR imaging approximately 48 hours after a global hypoperfusion-hypoxic event secondary to attempted suicide by hanging. CT scan (not shown) obtained 2 hours after the injury was interpreted as normal.
A and B, Properly windowed (250/150) DW image (A) versus an improperly windowed (850/400) DW image (B) in patient 5. Note the prominent gray–white matter differentiation even on the improperly windowed DW image in B.
C, Properly windowed DW image in a neurologically normal 40-year-old man for comparison shows that the gray–white matter differentiation is usually not so accentuated on DW images in a neurologically normal patient.
Download figure
Open in new tab
Download powerpoint
Fig 3.
Patient 6. A 40-year-old comatose man underwent MR imaging (performed with the 3.0-T magnet) approximately 3 days after cardiac arrest to aid in determining neurologic prognosis. CT scan (not shown) obtained within 4 hours after the arrest and anoxic insult was interpreted as normal.
A, T2-weighted image (windowed at 700/500) illustrates mildly pronounced gray–white matter differentiation of the cerebral hemispheres and gyral swelling.
B, TurboFLAIR image (windowed at 650/400) demonstrates similar findings as those on the T2-weighted image, with mildly pronounced gray–white matter differentiation.
C, Improper window/level (1150/650) obscures the diffuse cortical abnormality on this DW image. Although improperly windowed, there is accentuated gray–white matter differentiation, not usually present on DW images (as in Figs 1 and 2).
D, DW image with proper window/level of 250/150 shows that the cortical abnormality is more evident. The caudate nucleus (although slightly hyperintense) did not demonstrate as severely restricted diffusion as that in patient 1.
E, ADC map further illustrates the symmetric and uniform cortical restricted diffusion, with less prominent diffusion abnormality in the deep gray nuclei.

Tables

Figures

View popup

TABLE 1:

History, CT (or other imaging) timing/findings, DW MR timing, and outcome

Age/Gender	Brief history	Time of EEG after insult and findings	Time of CT/other imaging after inciting event and finding	Time of DW MR (days)	Outcome after support withdrawn
#1	Apneic episode during surgery, resuscitated.	1 day: burst suppression	CT: 4–5 hours, No significant abnormality.	3 days	BD
52/M	Apneic episode during surgery, resuscitated.	3 days: low voltage with diffuse slowing	CT: 4–5 hours, No significant abnormality.
		4 days: electrocerebral silence
#2	Cardiac arrest, hypokalemia, resuscitated.	2 days: electrocerebral silence	None performed.	1.5 days	BD
44/F	Cardiac arrest, hypokalemia, resuscitated.	2 days: electrocerebral silence
#3	Presumed head trauma & cardiac arrest, resuscitated	None performed	CT: less than 2 hours, Small amount of SAH in sylvian fissure	1.5 days	BD
34/F	Presumed head trauma & cardiac arrest, resuscitated
			NMBF: 4 days, no intracranial perfusion
#4	Acute intestinal bleed, hypovolemia, apnea, asystole, resuscitated	None performed	None performed	5 days	PVS
56/M
#5	Hanging/suicide with cerebral hypoperfusion	7 days: slow spike & periodic burst suppression	CT: within 2 hours, no significant abnormality	2 days	PVS
41/M	Hanging/suicide with cerebral hypoperfusion	7 days: slow spike & periodic burst suppression	CT: within 2 hours, no significant abnormality
#6	Cardiac arrest, resuscitated	3 days: electrocerebral silence	CT: within 4 hours, no significant abnormality	3 days	BD
40/M		3 days: electrocerebral silence	CT: within 4 hours, no significant abnormality

Note.—DW indicates diffusion-weighted; NMBF, nuclear medicine blood flow study; SAH, subarachnoid hemorrhage; BD, Brain Death; PVS, permanent vegetative state.