Size matters... but how do I know what size it is

One of the challenges that doctors, nurses, and technologists in the field of neurointervention face is the differing definitions regarding the sizes of the materials we use, or more specifically the nomenclature by which these sizes are communicated. In this field, where practitioners have grown accustomed to ‘odd’ units of measurement, such as mm Hg for blood pressure and cm H2O for intracranial pressure, the neurovascular device industry has provided an even bigger challenge with the many different denominations for the sizes of the devices we work with. During the formative years, neurointerventionists in training become increasingly accustomed to sizes of materials commonly used in the angiography suite. When a 4 F diagnostic catheter is requested, it is uncommon to convert this to the metric system, rather a common understanding of the required size is already established. Unfortunately, in the field of minimally invasive medicine, where sheaths, guide catheters, microcatheters, wires, and needles are used to deliver coils, stents, flow diverters, and liquid embolics, there is a trend to not only use the French scale but many other scales for sizing, such as ‘Inch’, ‘Gauge’, ‘Charrière’, and ‘mm’. To complicate matters further, the different scales do not measure changes in a commensurate manner—for example, the diameter increases with every unit in the French scale but decreases with the units in the Gauge scale. These unnecessarily obscure size definitions, in a field that requires an accuracy of micrometers, can only increase the risks of each procedure

High resolution magnetic susceptibility mapping of the substantia nigra in Parkinson's disease

Purpose: To determine if tissue magnetic susceptibility is a more direct marker of tissue iron content than other MR markers of iron. This study presents the first quantitative, in vivo measurements of the susceptibility of the substantia nigra in patients with Parkinson's disease. Materials and Methods: Nine patients and 11 controls were studied at 7 Tesla. Susceptibility maps were created by inverting the filtered phase maps associated with T2* weighted images. Results: On average, patients showed an increase in susceptibility of the pars compacta compared with controls, which correlates with the predicted increase in brain iron in Parkinson's disease. A rostral–caudal gradient in susceptibility was also observed in controls and patients. Conclusion: Susceptibility mapping may provide a new tool for studying the development of Parkinson's disease

Thrombectomy using the EmboTrap device: core laboratory-assessed results in 201 consecutive patients in a real-world setting

Neuro Imaging Researc

Very Late Leptomeningeal Collaterals-Potential New Way to Subdivide Modified Thrombolysis in Cerebral Ischemia (mTICI) 2B.

BACKGROUND: Studies have shown that the modified thrombolysis in cerebral ischemia (mTICI) 2B score is associated with better functional outcome; however, 50-99% reperfusion is a large range and there may be factors which can differentiate this further. The effects of very late leptomeningeal collaterals (VLLC) on mTICI-2B patients were studied. METHOD: A prospectively collected registry of anterior circulation AIS patients treated with the EmboTrap revascularization device from 2013 to 2016 was evaluated. Imaging parameters and timings, including the mTICI score were verified by an external core laboratory blinded to the clinical data. The final angiogram was examined for the appearance of VLLC in predicting 3‑month outcomes including excellent functional outcomes, defined as modified Rankin scale (mRS) 0-1, bleeding risk and mortality. RESULTS: A total of 177 consecutive anterior circulation stroke patients were included in the analysis. Of these 94 (53.1%) achieved only mTICI-2B reperfusion, 16/94 (17.0%) patients achieved excellent functional outcomes at 3 months and 26 (27.7%) had hyperdensity on follow-up computed tomography (CT). On univariate analysis, the presence of VLLC was inversely associated with excellent functional outcomes at 3 months and positively associated with mortality in patients with mTICI-2B reperfusion. On multivariate analysis VLLC was inversely associated with excellent outcomes (odds ratio 0.075, 95% confidence interval 0.007-0.765, P = 0.029) but not associated with mortality. CONCLUSION: The mTICI-2B grade may be further refined by secondary radiological markers. The VLLC sign is associated with the loss of excellent functional outcomes at 3 months. It is a simple sign to discriminate mTICI-2B into different grades but should be verified in larger populations from other centers.status: accepte

Posterior communicating and anterior communicating arteries on pre-thrombectomy computed tomography scans are associated with good outcomes irrespective of leptomeningeal collateral status

Neuro Imaging Researc