The purpose of this article is to review the imaging of spinal CSF leaks and to assist in the selection of appropriate imaging modalities in this condition. With dynamic CTM, the entire spinal canal can be examined, and spatial resolution is outstanding. These include digital subtraction myelography and dynamic or ultrafast CTM techniques. CSF motion is a combined effect of CSF production rate and Fig. seepage of the CSF visualized only dur-Myelographic Techniques for the Detection of Spinal CSF Leaks in Spontaneous Intracranial Hypotension ... 1Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710. The myelographic appearance of the leaks may vary, however, depending on the cause of the leak, rate of leakage, and imaging modality used. Consequently, intrathecal gadolinium should be used judiciously, and it is typically reserved for cases where first-line myelographic techniques have been unrevealing. 6). In this case, a second more rapid myelographic imaging test may be required to further investigate the site of leak, although information from the initial CTM may help target this investigation. Appearance:Clear and colourless White blood cells (WBC):0 – 5 cells/µL 1. Oleh Habifa. J Neurol Neursurg The recent murders of Black people at the hands of police officers and white vigilantes illustrate how, especially during a worldwide pandemic, systemic injustice and racism remain deeply ingrained in our society. Neither technique possesses the temporal resolution needed for accurately localizing high-flow leaks, making them less useful in this setting. A, Axial CT myelography (CTM) image shows focal contrast material leak (arrowhead) ventral to nerve root. In addition, the biomechanics of the thoracic spine during flexion and extension and the apposition of the dura to the normal kyphotic curvature of the posterior vertebral bodies may also play a role. Imaging at 24-48 -72 hrs to study CSF kinetics and search for ventricular filling or other abnormalities INDICATIONS Diagnosis of Normal (Low) Pressure Hydrocephalus 1 x. T2WI MRI brain showing prominent extra-axial CSF spaces. JOURNAL CLUB: Incidence of Complications Following Fluoroscopically Guided Lumbar Punctures and Myelograms, High-Resolution Single-Slice MR Myelography, Review. 8B —39-year-old woman with findings of high-flow CSF leak on conventional MRI. Agenesis of corpus callosum and frontal encephalocele. Spontaneous CSF leaks can, however, have a variety of appearances depending on their cause and rate of CSF leakage. For fast CSF leaks, then, selection of an imaging modality with high temporal resolution and rapid imaging after introduction of the myelographic agent are key to localizing the actual leak site. B, Image from digital subtraction myelography with patient in prone position shows leakage of contrast material (arrowhead) originating at level of disk space seen in A. B, Axial T1-weighted image with fat suppression after intrathecal gadolinium administration through same level much more clearly shows contrast material leaking along right C8 nerve root (arrowhead). These types of tears are often associated with very rapid CSF leakage and are most commonly found along the ventral surface of the thecal sac in the thoracic or lower cervical spine [17, 19, 20]. Cerebrospinal fluid within the cavities of the brain. Professor of Radiology and Pediatrics Director, Division of Nuclear Medicine October 2009. 1B —40-year-old woman with CSF leak caused by meningeal diverticulum. Medline, Google Scholar Fig. Because digital subtraction myelography best identifies leaks on the dependent surface of the thecal sac, some suspicion as to the leak's location based on prior imaging is helpful to best position the patient [35]. If the leak is fast enough, or imaging is too delayed, diffusion of myelographic contrast material or tracer throughout the leaked epidural CSF pool will render precise localization impossible. ... ranging from slow seepage of the CSF visualized only during Valsalva maneuvers to large rents from which CSF may pour rapidly . 4. C, Image from myelogram performed in right lateral decubitus position shows diverticulum (arrow) and leaked contrast material spreading in epidural space (arrowhead), originating from this site. Fig. 2. 2A —41-year-old man with CSF leak caused by degenerative abnormality. Although the site of CSF leakage can be generally assumed to be located somewhere along the length of the epidural collection, leaked CSF spreads away from the site of the original leak, and thus the precise site of leakage is often not able to be predicted by imaging the epidural collection itself. Broadly, the myelographic findings in patients with SIH are defined by the rate of CSF leakage, with three patterns commonly observed: fast leaks, slow leaks, and cases where no leak is identified (despite the presence of other manifestations of SIH). Fig. In most cases of SIH, CSF leakage originates from a single spinal level. Finite element analysis of periventricular lucency in hydrocephalus: extravasation or transependymal CSF absorption?. Spontaneous intracranial hypotension (SIH) is an increasingly recognized disease caused in nearly all cases by spontaneous spinal CSF leaks. The cingulate gyrus is herniating under the anterior falx and there is obliteration and asymmetry of the ambient cisterns in keeping with transtentorial herniation. No evidence of periventricular CSF seepage. FLAIR is the most sensitive MRI sequence for detection. Idiopathic Intracranial Hypertension: MRI. It is quite useful in the evaluation of high-flow leaks, but because digital subtraction myelography is not generally used to evaluate the entire spine, it is not generally used as the initial myelographic test for SIH. 10A —111In–diethylene triamine pentaacetic acid (DTPA) radionuclide cisternography. (Courtesy of Schievink W, Cedars-Sinai Medical Center, Los Angeles, CA). Several investigators have reported that MR myelography using intrathecal gadolinium is more sensitive for slow-flow or intermittent leaks than CTM, with CSF leaks identified in approximately 20% of patients for whom no leak was identified on prior CTM [30, 45] (Fig. A leak on MRI is shown by identifying fluid signal (marked T2 hyperintensity) in the epidural space (Fig. Extrathecal contrast material may be more conspicuous when digital subtraction is used.