T2-Sampling Perfection With Application-Optimized Contrasts by Using Flip Angle Evolution (SPACE) Protocol MRI: A Safe, Minimally Invasive Screening Tool for Spinal CSF Leak Causing Spontaneous Intracranial Hypotension

Abstract

Spontaneous intracranial hypotension (SIH) due to a spinal cerebrospinal fluid (CSF) leak is secondary cause of headache with potentially devastating consequences. Its diagnosis is complicated owing to the lack of a reasonable, minimally invasive screening test. This results in many patients remaining undiagnosed for years after the headache onset. Current testing approaches are either overly invasive, namely the CSF infusion protocol or both invasive and insensitive viz. lumbar puncture (LP) with an opening pressure (OP) or computed tomography myelogram (CTM). These diagnostic methods are frequently employed in a clinical setting since they require access to the thecal space; they unfortunately have a dearth of sensitivity. CTM will not document a leak if it is intermittent or very slow and in the setting of a spinal CSF leak, the OP on LP may be high, low, or normal. A potential remedy for this state is the T2-sampling perfection with application-optimized contrasts by using flip angle evolution (SPACE) protocol spinal magnetic resonance imaging (MRI). We present two cases that demonstrate its potential value as a screening tool. It is well known for its high sensitivity for identifying spinal pathology and is minimally invasive, making it a good choice for a screening modality when diagnosing possible SIH cases.

Keywords: ds myelogram; screening tool; spinal csf leak; spontaneous intracranial hypotension (sih); t2-space protocol mri.

Figure 1. The thoracolumbar longitudinal and cross-sectional T2-SPACE MR myelogram images.

(A and B) At the T11-T12 level, green arrows indicate fluid outside thecal space associated with a possible CSF leak. (C) DS myelogram confirms the localization of the CSF leak. Dye escaping the thecal sac can be observed at the level T12 to L1 (blue oval circle). The image is taken from Daripa B, Lucchese S: T2-SPACE protocol MRI: a safe, minimally invasive screening tool for spinal CSF leak causing spontaneous intracranial hypotension (P0253). J Headache Pain. 2021, 22:1-153. MR: magnetic resonance; CSF: cerebrospinal fluid; DS: digital subtraction

Figure 2. The thoracolumbar sagittal and cross-sectional T2 MR myelogram imaging.

(A and D) At the T12 level, green arrows indicate an area of fluid outside the thecal space. (C) The DS myelogram image shows dye extravasation visualized in the black oval ring. (B) A 3D-reconstruction image illustrates the leak site localization at T12 (thick green arrow). The image is taken from Daripa B, Lucchese S: T2-SPACE protocol MRI: a safe, minimally invasive screening tool for spinal CSF leak causing spontaneous intracranial hypotension (P0253). J Headache Pain. 2021, 22:1-153. MR: magnetic resonance; CSF: cerebrospinal fluid; DS: digital substraction