ARRS Case of the Week


Case Author: Megan K. Strother, MD, Vanderbilt University Medical Center


21-year-old woman with chronic headaches.

Imaging Findings

Axial T2-weighted MR image (A) shows a rounded hyperintense filling defect in the right transverse sinus. Axial CT angiogram (B) shows the round filling defect. The transverse sinus otherwise appears normal. Anteroposterior cerebral angiogram (C) shows the contrast-opacified transverse sinus with a rounded filling defect (arrow).

  • Arachnoid granulation
  • Dural arteriovenous fistula
  • Dural venous sinus thrombosis
  • Transverse sinus hypoplasia


Arachnoid granulation

Teaching Points

In 96% of cases, arachnoid granulations are associated with a vein. Arachnoid granulations are isointense to CSF in all MRI sequences. Most arachnoid granulations are incidental findings, although they have rarely been reported to cause symptoms due to venous hypertension.

Suggested Readings

Leach JL, Jones BV, Tomsick TA, Stewart CA, Balko MG. Normal appearance of arachnoid granulations on contrast-enhanced CT and MR of the brain: differentiation from dural sinus disease. AJNR 1996; 17:1523–1532
Lianga L, Korogia Y, Sugaharaa T, et al. Normal structures in the intracranial dural sinuses: delineation with 3D contrast-enhanced magnetization prepared rapid acquisition gradient-echo imaging sequence. AJNR 2002; 23:1739–1746

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