Watershed infarction

Clinical:

  • A 16 years old boy
  • Underlying liver failure
  • Presented with poor GCS
  • Also had one episode of hypotensive and bradycardia
MRI of brain in axial planes; (A) T1WI, (B) T2WI, (C) DWI and (D) ADC sequences.

MRI findings:

  • Areas of restricted diffusion in white matter at and above level of lateral ventricles, extending from frontal to parietal lobe conforming to anterior and posterior borderzone area
  • The changes are hypointense on T1, hyperintense on T2 and FLAIR and show restricted diffusion on DWI sequence
  • The changes are bilateral, almost symmetrical with confluent lesions in rosary pattern
  • No blooming artifact to suggest bleed

Diagnosis: Acute bilateral borderzone (watershed) infarction.

Discussion:

  • Border zone or watershed infarction is also known as hypotensive cerebral infarction
  • It is infarction resulting from insufficient cerebral blood flow to meet metabolic demands
  • Location: 2 types
    • Borderzone between the major arterial territories-typically at gray white matter junction
    • Borderzone between perforating arteries-
  • Morphology
    • Cortical based wedge shaped abnormality between vascular territories
    • deep white matter-rosary or string of pearl/beads appearance, multiple round foci in linear orientation within centrum semiovale, can be unilateral
  • Pseudolaminar necrosis= curvilinear, gyriform T1-hyperintense regions
  • Diffuse supratentorial abnormality following global asphyxia (white cerebellar or reversal sign)

 

 

Author: radhianahassan