A study by Dwyer et al [41] that reviewed more than 200 MRVs in suspected cases of pseudotumor cerebri found that 52% of scans showed evidence of venous obstruction in the dominant side of venous circulation. This was statistically higher than in control groups. It is important to note that reversibility of venous outflow obstruction can be seen on MRV in these patients following lumbar puncture, which argues that the presence of venous outflow obstruction could be secondary to the increased intracranial pressure itself [42]. When cerebellar tonsillar ectopia of >5 mm is identified, imaging and clinical consideration of PTCS are warranted to avoid misdiagnosis as Chiari I [43]. In addition to the initial MRV in patients with suspected PTCS, a second MRV following CSF drainage may be helpful. Venous sinus occlusion and arteriovenous fistulas may produce PTCS. MRV is indicated when there is concern for venous sinus thrombosis, especially in children with intracranial extension of infection. Children with mastoiditis are at a particularly high risk for venous sinus thrombosis. Girls using oral contraceptives are also at increased risk for thrombosis. The use of contrast in MRV depends on institutional preferences. Contrast-enhanced MRV may be helpful when evaluating areas such as the sigmoid venous sinuses, a location often degraded by artifact on noncontrast MRVs. Arteriography In patients with evidence for stroke on CT or MRA, arteriography may be helpful for further evaluation, especially when intervention such as thrombolysis or treatment of vascular malformations is considered. Arteriography is also more sensitive in detecting small vessel disease and arterial dissection and may be a useful examination if results of MRA or CTA are unclear and there is strong suspicion for such. Variant 3: Child. Sudden severe headache (thunderclap headache). Initial imaging. Radiography There is no role for radiography in children with sudden severe headache.
Headache Child PCAs. A study by Dwyer et al [41] that reviewed more than 200 MRVs in suspected cases of pseudotumor cerebri found that 52% of scans showed evidence of venous obstruction in the dominant side of venous circulation. This was statistically higher than in control groups. It is important to note that reversibility of venous outflow obstruction can be seen on MRV in these patients following lumbar puncture, which argues that the presence of venous outflow obstruction could be secondary to the increased intracranial pressure itself [42]. When cerebellar tonsillar ectopia of >5 mm is identified, imaging and clinical consideration of PTCS are warranted to avoid misdiagnosis as Chiari I [43]. In addition to the initial MRV in patients with suspected PTCS, a second MRV following CSF drainage may be helpful. Venous sinus occlusion and arteriovenous fistulas may produce PTCS. MRV is indicated when there is concern for venous sinus thrombosis, especially in children with intracranial extension of infection. Children with mastoiditis are at a particularly high risk for venous sinus thrombosis. Girls using oral contraceptives are also at increased risk for thrombosis. The use of contrast in MRV depends on institutional preferences. Contrast-enhanced MRV may be helpful when evaluating areas such as the sigmoid venous sinuses, a location often degraded by artifact on noncontrast MRVs. Arteriography In patients with evidence for stroke on CT or MRA, arteriography may be helpful for further evaluation, especially when intervention such as thrombolysis or treatment of vascular malformations is considered. Arteriography is also more sensitive in detecting small vessel disease and arterial dissection and may be a useful examination if results of MRA or CTA are unclear and there is strong suspicion for such. Variant 3: Child. Sudden severe headache (thunderclap headache). Initial imaging. Radiography There is no role for radiography in children with sudden severe headache.