More articles from Functional
- Acute Ischemic Stroke or Epileptic Seizure? Yield of CT Perfusion in a “Code Stroke” Situation
CTP patterns helped to differentiate acute ischemic stroke from epileptic seizure in a “code stroke“ situation. The results indicate that a hyperperfusion pattern, especially if not restricted to a vascular territory, may suggest reconsideration of intravenous thrombolytic therapy.
- Neurite Orientation Dispersion and Density Imaging for Assessing Acute Inflammation and Lesion Evolution in MS
Neurite orientation dispersion and density imaging (NODDI) assesses microstructural features of neurites contributing to diffusion imaging signals. Twenty-one subjects with MS underwent serial enhanced MRIs including NODDI, the key metrics of which are the neurite density and orientation dispersion index. Twenty-one age- and sex-matched healthy controls underwent unenhanced MR imaging with the same protocol. NODDI is a promising tool with the potential to detect acute MS inflammation. The observed heterogeneity among lesions may correspond to gradients in severity and clinical recovery after the acute phase.
- Recent Administration of Iodinated Contrast Renders Core Infarct Estimation Inaccurate Using RAPID Software
Patients who received IV iodinated contrast in proximity (<8 hours) to CTA/CTP as part of a separate imaging study had a much higher likelihood of core infarct underestimation with RAPID software compared with contrast-naive patients. Over-reliance on RAPID postprocessing for treatment disposition of patients with extended window emergent large-vessel occlusion should be avoided, particularly in cases with recent IV contrast administration.
- Variability of T2-Relaxation Times of Healthy Lumbar Intervertebral Discs is More Homogeneous within an Individual Than across Healthy Individuals
Using prospectively acquired T2-relaxometry data from 606 intervertebral discs in 101 volunteers without back pain in a narrow age range (25–35 years), the authors calculated intra- and intersubject variation in T2 times of IVDs graded by 2 neuroradiologists on the Pfirrmann scale. Intrasubject variation of IVDs was assessed relative to other healthy IVDs (Pfirrmann grade, #2) in the same individual. Multiple intersubject variability measures were calculated using healthy extraneous references ranging from a single randomly selected IVD to all healthy extraneous IVDs, without and with segmental stratification. They conclude that the study demonstrates a significantly higher variation in the T2 times of IVDs across subjects, and suggests that normative measures based on the T2 times of healthy lumbar IVDs from the same individual are likely to provide the most discriminating means of identifying degenerated IVDs on the basis of T2 relaxometry.
- Monro-Kellie Hypothesis: Increase of Ventricular CSF Volume after Surgical Closure of a Spinal Dural Leak in Patients with Spontaneous Intracranial Hypotension
Nineteen patients with spontaneous intracranial hypotension with a proved spinal CSF leak were investigated between July 2014 and 2017. Brain MR imaging-based volumetry at baseline and after surgery was performed with FreeSurfer. In addition, the spontaneous intracranial hypotension score, ranging from 0 to 9, with 0 indicating very low and 9 very high probability of spinal CSF loss, was calculated. The authors conclude that the study demonstrated a significant increase in ventricular CSF volume in the early follow-up after surgical closure of the underlying spinal dural breach, and may provide a causal link between spinal CSF loss and spontaneous intracranial hypotension. The concomitant decrease in the spontaneous intracranial hypotension score postoperatively implies the restoration of an equilibrium within the CSF compartment.