Severe sudden headaches can be associated with SAH and intracranial hemorrhage that may occur with aneurysms or other vascular malformations, such as AVMs and cavernomas. Neuroimaging of children with severe or unusual head pain who have a first-degree relative with an aneurysm or other vascular abnormality is indicated, as these vascular pathologies can be familial but are otherwise uncommon [39]. The cornerstone for the diagnosis of SAH is a noncontrast CT scan; however, the use of MRI techniques such as proton-density-weighted imaging, susceptibility-weighted imaging (SWI)/gradient-recalled echo (GRE) imaging, or T2-weighted fluid- attenuated inversion recovery (FLAIR) imaging improves the diagnosis of acute SAH, as conventional sequences are insensitive to the finding [21]. A study by Mitchell et al [49] found that sensitivity to SAH varied among MR sequence from 50% to 94% in acute SAH and from 33% to 100% in subacute SAH. The most sensitive sequences were FLAIR and SWI/GRE. It is important to note that signal in the sulci on the FLAIR sequence can be artifactually increased in children receiving propofol and supplemental oxygenation and can mimic SAH. Meningitis can also give this appearance. CT In the acute setting, noncontrast CT is indicated in the evaluation of acute thunderclap headache. The sensitivity of CT for the detection of acute SAH is greater than MRI at 98% with a specificity of 99% [50]. CT is often the initial imaging study of choice because of availability and lack of need for sedation. CTV Except in cases of thunderclap headache related to an AVM, CTV is usually not indicated in patients with thunderclap headache. MRV Except in cases of thunderclap headache related to an AVM, MRV is usually not indicated in patients with thunderclap headache. The use of contrast in MRV depends on institutional preferences.
Headache Child PCAs. Severe sudden headaches can be associated with SAH and intracranial hemorrhage that may occur with aneurysms or other vascular malformations, such as AVMs and cavernomas. Neuroimaging of children with severe or unusual head pain who have a first-degree relative with an aneurysm or other vascular abnormality is indicated, as these vascular pathologies can be familial but are otherwise uncommon [39]. The cornerstone for the diagnosis of SAH is a noncontrast CT scan; however, the use of MRI techniques such as proton-density-weighted imaging, susceptibility-weighted imaging (SWI)/gradient-recalled echo (GRE) imaging, or T2-weighted fluid- attenuated inversion recovery (FLAIR) imaging improves the diagnosis of acute SAH, as conventional sequences are insensitive to the finding [21]. A study by Mitchell et al [49] found that sensitivity to SAH varied among MR sequence from 50% to 94% in acute SAH and from 33% to 100% in subacute SAH. The most sensitive sequences were FLAIR and SWI/GRE. It is important to note that signal in the sulci on the FLAIR sequence can be artifactually increased in children receiving propofol and supplemental oxygenation and can mimic SAH. Meningitis can also give this appearance. CT In the acute setting, noncontrast CT is indicated in the evaluation of acute thunderclap headache. The sensitivity of CT for the detection of acute SAH is greater than MRI at 98% with a specificity of 99% [50]. CT is often the initial imaging study of choice because of availability and lack of need for sedation. CTV Except in cases of thunderclap headache related to an AVM, CTV is usually not indicated in patients with thunderclap headache. MRV Except in cases of thunderclap headache related to an AVM, MRV is usually not indicated in patients with thunderclap headache. The use of contrast in MRV depends on institutional preferences.