- Spontaneous Intracranial Hypotension: A Systematic Imaging Approach for CSF Leak Localization and Management Based on MRI and Digital Subtraction Myelography
Using spinal MR imaging to dichotomize patients with spontaneous intracranial hypotensioninto spinal longitudinal extradural CSF collection positive and negative populations accurately determines the nature of their underlying CSF leak (mechanical dural tear versus CSF venous fistula or nerve root sleeve leak), correctly predicts in whom autologous nondirected and directed epidural blood patch may work and in whom it will fail, and finally prescribes the positioning (prone versus decubitus) for subsequent dynamic myelography providing the most efficient pathway to definitive leak localization and repair. Using this systematic approach, the authors have been able to identify the exact site of CSF leakage in 27 (87%) of 31 consecutive patients referred to their institution with MR imaging evidence of SIH.
- Moving Toward a Consensus DSC-MRI Protocol: Validation of a Low–Flip Angle Single-Dose Option as a Reference Standard for Brain Tumors
DSC-MR imaging using preload, intermediate (60°) flip angle and postprocessing leakage correction has gained traction as a standard methodology. Simulations suggest that DSC-MR imaging with flip angle = 30° and no preload yields relative CBV practically equivalent to the reference standard. Eighty-four patients with brain lesions were enrolled in this 3-institution study. Forty-three patients satisfied the inclusion criteria. DSC-MR imaging (3T, single-dose gadobutrol, gradient recalled-echo–EPI, TE=20–35 ms, TR=1.2–1.63 seconds) was performed twice for each patient, with flip angle = 30°–35° and no preload (P-) or provided preload (P+) for an intermediate flipangle = 60°. Compared with 60°/P+/C+, 30°/P-/C+ had closest mean standardized relative CBV, highest Lin concordance correlation coefficient, and lowest Bland-Altman bias.
- Measuring Glymphatic Flow in Man Using Quantitative Contrast-Enhanced MRI
In this technical report, the authors used MR myelography to demonstrate the feasibility of T1 mapping to quantify contrast concentration to analyze glymphatic flow in man. There is increasing interest in its use as a biomarker and potential therapeutic target in Alzheimer disease.