In the emergency setting, if a brain tumor is suspected, CT without IV contrast can be performed initially; however, a contrast-enhanced study may be indicated if it is not possible to perform an MRI scan of the brain. In patients with thunderclap headache, subarachnoid hemorrhage (SAH) from a ruptured aneurysm or arteriovenous malformation must be excluded; therefore, a noncontrast CT scan of the head is the imaging modality of choice as it is superior to MRI in detecting acute SAH [20]. If subarachnoid or parenchymal hemorrhage is detected, further evaluation for aneurysm or vascular malformation must be performed. This evaluation can be accomplished by CT angiography (CTA), conventional arteriography, or MR angiography (MRA) [21,22]. MRV MR venography (MRV) is the study of choice in children with suspected venous outflow stenosis, such as those with pseudotumor cerebri, or those with venous sinus thrombosis, such as mastoiditis. MRV can be performed with or without IV contrast. MRV with contrast can be helpful in the detection of intracranial sinovenous stenosis that can go undetected because of artifactual flow voids in the transverse sinuses on traditional noncontrast (time- of-flight) MRV [24]. CTV If MRV is not possible, or in cases in which the results of MRV are ambiguous, imaging with contrast-enhanced CT venography (CTV) has been found to be a fast, widely accessible alternative approach with high sensitivity and specificity in detecting venous sinus thrombosis [25]. MRV is generally preferred over CTV because of radiation concerns. MRA If subarachnoid or parenchymal hemorrhage is detected, further evaluation for aneurysm or vascular malformation must be performed. This evaluation can be accomplished by MRA, CTA, or conventional arteriography [21,22]. MRA can be performed without IV contrast and is easily added to a standard MRI study if a stroke or hemorrhage is detected.
Headache Child PCAs. In the emergency setting, if a brain tumor is suspected, CT without IV contrast can be performed initially; however, a contrast-enhanced study may be indicated if it is not possible to perform an MRI scan of the brain. In patients with thunderclap headache, subarachnoid hemorrhage (SAH) from a ruptured aneurysm or arteriovenous malformation must be excluded; therefore, a noncontrast CT scan of the head is the imaging modality of choice as it is superior to MRI in detecting acute SAH [20]. If subarachnoid or parenchymal hemorrhage is detected, further evaluation for aneurysm or vascular malformation must be performed. This evaluation can be accomplished by CT angiography (CTA), conventional arteriography, or MR angiography (MRA) [21,22]. MRV MR venography (MRV) is the study of choice in children with suspected venous outflow stenosis, such as those with pseudotumor cerebri, or those with venous sinus thrombosis, such as mastoiditis. MRV can be performed with or without IV contrast. MRV with contrast can be helpful in the detection of intracranial sinovenous stenosis that can go undetected because of artifactual flow voids in the transverse sinuses on traditional noncontrast (time- of-flight) MRV [24]. CTV If MRV is not possible, or in cases in which the results of MRV are ambiguous, imaging with contrast-enhanced CT venography (CTV) has been found to be a fast, widely accessible alternative approach with high sensitivity and specificity in detecting venous sinus thrombosis [25]. MRV is generally preferred over CTV because of radiation concerns. MRA If subarachnoid or parenchymal hemorrhage is detected, further evaluation for aneurysm or vascular malformation must be performed. This evaluation can be accomplished by MRA, CTA, or conventional arteriography [21,22]. MRA can be performed without IV contrast and is easily added to a standard MRI study if a stroke or hemorrhage is detected.