When performed in the decubitus position, 2 separate contrast injections may be required due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44]. Variant 5: Adult. Chronic daily headache from suspected intracranial hypotension with negative initial brain and spine imaging, but with history and clinical examination suggesting CSF leakage. Next imaging study. Negative initial imaging should not preclude continued diagnostic workup in a patient with clinically suspected SIH [4,53]. Approximately 20% of initial brain MRIs and 46% to 67% of initial spine imaging in patients with clinically suspected SIH may have normal results [4]. Of note, CSF-venous fistulas and slow meningeal diverticular leaks are often subtle imaging findings that may not be readily detectable using conventional imaging techniques with limited temporal resolution and may require follow-up imaging with more advanced imaging procedures to definitely identify or exclude a more subtle spinal CSF leak source [7,53,68-70]. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the subsequent imaging of suspected SIH. The spine has been shown to represent the anatomical source of most symptomatic CSF leaks and venous fistulas, such that the imaging investigation of leak source should be directed primarily toward the spine and not intracranially [22]. CT Myelography Dynamic Complete Spine Dynamic CT myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [37,38]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic CT myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,37- 39].
Imaging of Suspected Intracranial Hypotension PCAs. When performed in the decubitus position, 2 separate contrast injections may be required due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44]. Variant 5: Adult. Chronic daily headache from suspected intracranial hypotension with negative initial brain and spine imaging, but with history and clinical examination suggesting CSF leakage. Next imaging study. Negative initial imaging should not preclude continued diagnostic workup in a patient with clinically suspected SIH [4,53]. Approximately 20% of initial brain MRIs and 46% to 67% of initial spine imaging in patients with clinically suspected SIH may have normal results [4]. Of note, CSF-venous fistulas and slow meningeal diverticular leaks are often subtle imaging findings that may not be readily detectable using conventional imaging techniques with limited temporal resolution and may require follow-up imaging with more advanced imaging procedures to definitely identify or exclude a more subtle spinal CSF leak source [7,53,68-70]. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the subsequent imaging of suspected SIH. The spine has been shown to represent the anatomical source of most symptomatic CSF leaks and venous fistulas, such that the imaging investigation of leak source should be directed primarily toward the spine and not intracranially [22]. CT Myelography Dynamic Complete Spine Dynamic CT myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [37,38]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic CT myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,37- 39].