"type 1: dural tear"
"type 2: lateral leak"
"type 3: CSF-venous fistula 16,24,26,35,36"
"type 4: distal nerve root sleeve leaks 28"
"Off-label warning: The use of gadolinium-based contrast agents for intrathecal administration is not approved by regulatory agencies such as the FDA. Read more: intrathecal gadolinium"
"type 1: dural tear"
"type 2: lateral leak"
"type 3: CSF-venous fistula"
"Nuclear medicine myelography can also be employed, using intrathecal 111Indium-DTPA, with images obtained typically at 1, 2, 4, 24, and in some instances even 48 hours post-injection 9. Localisation can be seen as a focal accumulation of activity. In some cases, only indirect evidence of a leak being present somewhere is available, which is only really useful in instances where the diagnosis of CSF leak remains uncertain. Indirect evidence includes 9:"
"Targeted epidural blood or fibrin glue patches for ventral dural leaks can either be performed using a translaminar approach, as for initial non-targeted injections, or aimed at entering the ventral epidural space using a transforaminal approach at one or more levels and potentially from both sides 20. For lateral dural leaks from nerve root sleeves or meningeal diverticula, a transforaminal approach can be used to target the dural defect. For CSF-venous fistulas, a good clinical response to fibrin glue is more likely when the spread of injectate is concordant with the location(s) of the draining veins of the fistula as shown by myelography 37."
"primary: usually referred to as spontaneous intracranial hypotension (SIH)"
"Intracranial hypotension results from a CSF leak somewhere along the neuraxis, usually below the hydrostatic indifference point, resulting in alterations in the equilibrium between the volumes of intracranial blood, CSF, and brain tissue (Monro-Kellie hypothesis). A decrease in CSF volume leads to compensatory dilatation of the vascular spaces, mostly the venous side due to its higher compliance."
"Off-label warning: The use of gadolinium-based contrast agents for intrathecal administration is not approved by regulatory agencies such as the FDA. Read more: intrathecal gadolinium"
"B. either or both of the following:"
"As not all patients with SIH experience headache, some authors modify these diagnostic criteria to include patients whose symptoms are best explained by SIH but who do not have headache 31."
"It should be noted that most patients with SIH do not, in fact, have low opening pressures at lumbar puncture. In one study, only 34% patients had pressures"
"C1-C2 false localising sign"
"A particular example of this is pooling of contrast/CSF at the C1/2 level posteriorly. This can be incorrectly attributed to a local leak, when in fact this is not the case. This is referred to as the C1-C2 false localising sign 10-12."
"A useful mnemonic to remember some of the aforementioned features is SEEPS."
"In 2025 SIH-RADS (Spontaneous Intracranial Hypotension Reporting and Data System) has been proposed to standardise reporting of dynamic CT myelography in the setting of suspected spontaneous intracranial hypotension 58."
"Off-label warning: The use of gadolinium-based contrast agents for intrathecal administration is not approved by regulatory agencies such as the FDA. Read more: intrathecal gadolinium"
"MR myelography"
Expected headings
"Imaging strategy"
"MRI brain with contrast"
"MRI spine"
"Myelography"
"Dynamic CT myelography"
"Digital subtraction myelography"
"Fluoroscopic myelography"
"MR myelography"
"Nuclear medicine myelography"
"The typical presentation is postural (orthostatic) headache which is relieved by lying in a recumbent position, usually within 15-30 minutes 12. This is, however, not always the case and the orthostatic quality of the headache may subside in the long term. Some patients report headaches that are not relieved by lying down, others have headaches that develop slowly during the course of the day (“second half of the day” headaches) 26 or are precipitated by the Valsalva manoeuvre. Other symptoms include nausea, vomiting, neck pain, visual and hearing disturbances including tinnitus, and vertigo 17,26."
"weakness of upper limbs, with normal power in the face, neck and lower limbs (i.e. a person-in-a-barrel syndrome)"
"intracranial venous thrombosis is a well-recognised, albeit uncommon, complication and may involve the cortical veins and/or dural venous sinuses 19"
"As understanding, technology and techniques have evolved so too have recommended imaging strategies. These will also depend on the local expertise. Generally, the approach should consist of:"
"It also enables the calculation of the Bern score, a predictive score that stratifies patients into high, intermediate or low probability of finding a spinal CSF leak/CSF-venous fistula at myelography 33,46,48. This in turn can help guide further investigations."
"If further localisation of a leak is required then a variety of myelographic techniques are useful. Which is chosen depends what the initial imaging of the brain and spine have shown 25 as well as on local preference, policies and available equipment and expertise."
"trauma (e.g. penetrating injury)"
"iatrogenic (e.g. lumbar puncture, surgery)"
"The most common qualitative finding is pachymeningeal thickening and enhancement followed by dural venous engorgement, tonsillar herniation, and subdural collection; however, these features are not always present, which is why quantitative findings are very helpful in making a more accurate diagnosis on MRI."
"pachymeningeal enhancement (most common finding): becomes less prevalent over time after the onset of symptoms; hence, in patients with a chronic duration of symptoms in whom clinically the headache pattern also changes from orthostatic to atypical constant headache, the absence of dural enhancement may hinder the diagnosis of intracranial hypotension 15"
"prominence of enlarged intercavernous sinuses is not a sensitive or specific finding; however, it is important to recognise that in cases of intracranial hypotension, should not be mistaken for a pituitary lesion 14"
"Ideally this can be performed at the same time as the MRI brain but need not consist of a full mulitparameter study; heavily T2 weighted fat saturated sequences through the spinal canal and adjacent soft tissues suffice 25. These can be performed as 3D sequences (ideally) or multiplanar 2D sequences."
"The purpose of MRI spine is not to localise the site of the leak, as this is seldom possible by non-invasive means, but rather to determine the most likely type of spinal CSF leak. This is based on the presence or absence of epidural fluid, known as a spinal longitudinal epidural collection (SLEC). This then determines what type of myelography to perform in order to localise the leak. When epidural fluid is shown on MRI (a so-called 'wet leak') then a dural defect and a type 1 or type 2 leak is present. In the absence of epidural fluid (a 'dry leak'), a CSF-venous fistula is most likely to be the cause (or rarely a far lateral nerve root sleeve tear or CSF-lymphatic fistula)."
"There are five main options each with pros and cons:"
"Unlike traditional CT myelography where intrathecal contrast is introduced a significant time prior to the CT, often in the fluoroscopy room, allowing the contrast to mix evenly throughout the CSF, in dynamic CT myelography, contrast is introduced with the patient already positioned in the CT scanner, either prone or decubitus depending on the likely cause of CSF leak (i.e. prone if ventral leak, and decubitus if lateral leak or CSF-venous fistulas) and dense contrast visualised to identify the site of leakage 24,25. This usually requires multiple acquisitions, and thus can have high radiation doses 48."
"Nuclear medicine myelography can also be employed, using intrathecal 111Indium-DTPA, with images obtained typically at 1, 2, 4, 24, and in some instances even 48 hours post-injection 9. Localisation can be seen as a focal accumulation of activity. In some cases, only indirect evidence of a leak being present somewhere is available, which is only really useful in instances where the diagnosis of CSF leak remains uncertain. Indirect evidence includes 9:"