Measurement of renal blood flow by phase-contrast magnetic resonance imaging during septic acute kidney injury: a pilot investigation.

Objective: In septic patients, decreased renal perfusion is considered to play a major role in the pathogenesis of acute kidney injury. However, the accurate measurement of renal blood flow in such patients is problematic and invasive. We sought to overcome such obstacles by measuring renal blood flow in septic patients with acute kidney injury using cine phase-contrast magnetic resonance imaging.

Ciné phase-contrast magnetic resonance imaging for the measurement of renal blood flow.

During critical illness, reductions in renal blood flow (RBF) are believed to be a major cause of kidney dysfunction, and therapy is often aimed at restoration of RBF. Despite this, our ability to measure RBF during critical illness has been limited by the invasiveness of the available techniques. Ciné Phase-Contrast Magnetic Resonance Imaging (CPC-MRI) represents an entirely noninvasive, contrast-free method of measuring blood flow with the potential of enabling the measurement of blood flow to major organs including the kidney.

Assessment of suitability of thrombolysis in middle cerebral artery infarction: a proof of concept study of a stereologically-based technique.

Background: The extent of cerebral ischemia, assessed by the Alberta Stroke Program Early CT Score (ASPECTS) method and unaided visual determination of the CT Summit Criterion, correlates with increased risk of intracerebral hemorrhage following rt-PA administration. Concerns about the accuracy of the unaided visual assessment in the estimation of infarct size and the conservative nature of the ASPECTS method led us to develop a new method (MCAGrid) based on stereological grid counting and a digital atlas of the middle cerebral artery (MCA) infarct territory.

Methods: We tested the hypotheses that the stereological method increases the accuracy of infarct estimation and that the number of patients deemed eligible for thrombolysis is greater with this method than with existing methods.

The ASPECTS template is weighted in favor of the striatocapsular region.

The extent of cerebral infarction correlates with increased risk of intracerebral hemorrhage (ICH) following recombinant tissue plasminogen activator (rt-PA) administration. The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used, validated method which assesses involvement of 10 selected regions of the MCA territory. An ASPECTS score >7 is associated with a higher risk of ICH following thrombolysis than lower scores.

Hypertensive encephalopathy.

The case report of a patient with hypertensive encephalopathy is presented here. The findings of reversible bilateral thalamic changes on T2-weighted MR imaging is an atypical manifestation of the reversible posterior leucoencephalopathy syndrome (RPLS), which is the neuroradiological correlate of hypertensive encephalopathy. The importance of prompt and accurate diagnosis of hypertensive encephalopathy / RPLS is stressed.