Annals of Indian Academy of Neurology
IMAGES IN NEUROLOGY
Year
: 2022  |  Volume : 25  |  Issue : 4  |  Page : 710-

The differential arterial flow signal sign: An early brain MRI sign of circulatory arrest


Vikas Bhatia1, Saifullah Khalid1, Raghav Seth1, Atul Saroch2,  
1 Department of Radio-diagnosis and Imaging, PGIMER, Chandigarh, India
2 Department of Internal Medicine, PGIMER, Chandigarh, India

Correspondence Address:
Vikas Bhatia
Neuroradiology Section, Department of Radio-Diagnosis, PGIMER, Chandigarh - 160 012
India




How to cite this article:
Bhatia V, Khalid S, Seth R, Saroch A. The differential arterial flow signal sign: An early brain MRI sign of circulatory arrest.Ann Indian Acad Neurol 2022;25:710-710


How to cite this URL:
Bhatia V, Khalid S, Seth R, Saroch A. The differential arterial flow signal sign: An early brain MRI sign of circulatory arrest. Ann Indian Acad Neurol [serial online] 2022 [cited 2022 Nov 28 ];25:710-710
Available from: https://www.annalsofian.org/text.asp?2022/25/4/710/342611


Full Text



A 52-year-old male with encephalopathy for 5 days, underwent an MRI brain examination. On MRI [Figure 1], there was the loss of signal void in bilateral internal carotid arteries (ICA); however, with preserved flow void in the intracranial arteries on the T2W images. Susceptibility weighted imaging (SWI) showed accentuated susceptibility changes in the intracranial arteries with hyperintense signal in bilateral ICA. We term this sign as a “differential arterial flow signal sign.” The likely cause of hyperintense signal in the ICA in our case is slow/stagnant flow, whereas hypointense signal on T2W/SWI in the intracranial arteries represent the loss of signal due to increased cerebral oxygen extraction and deoxygenated blood representing cerebral autoregulation. The increased susceptibility effect in the intracranial arteries has been reported earlier in a series of brain-dead patients due to hypoxia.[1]{Figure 1}

We also observed prominent medullary and cortical veins on the SWI. This finding has been previously reported to be due to increased oxygen extraction, increased deoxyhemoglobin and/or venous stasis/dilatation after cell death. A similar finding is also seen in stroke, trauma, comatose patients, and brain death.[2] MR angiography and contrast imaging were not done in our case, and the patient was immediately shifted to emergency, where he was declared dead due to cardio-respiratory arrest.

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Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Tsai FY, Lee KW, Kao HW, Chen CY. Susceptibility weighted imaging, an additional tool to diagnose brain death: Initial experience. Neuroradiol J 2012;25:505-8.
2Sohn CH, Lee HP, Park JB, Chang HW, Kim E, Kim E, et al. Imaging findings of brain death on 3-tesla MRI. Korean J Radiol 2012;13:541-9.