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Peter D Schellinger

Publications and source records attributed to Peter D Schellinger.

38 records · Page 3Linked to original sources
PubMed2002

Diffusion-weighted imaging in acute stroke--a tool of uncertain value?

The concept of a mismatch between the lesion volume in diffusion- and perfusion-weighted magnetic resonance imaging (MRI) indicating 'tissue at risk of infarction' is based on the assumption that tissue with diffusion slowing in diffusion-weighted MRI (DWI) or decreased values of the apparent diffusion coefficient represents irreversibly damaged tissue. Recent experimental as well as clinical studies, however, have shown that tissue with diffusion slowing may well normalize if the hypoperfusion is moderate or transient. We will interpret these findings in the light of experimental data and suggest a way for the interpretation of different time courses of lesion development in DWI within a clinical MRI protocol. MR stroke imaging delivers important information in acute stroke, particularly in defining the 'tissue at risk of infarction'.

Brain Ischemia↗
PubMed2002

Comparison of CT and CT angiography source images with diffusion-weighted imaging in patients with acute stroke within 6 hours after onset.

BACKGROUND AND PURPOSE: Although stroke MRI has advantages over other diagnostic imaging modalities in acute stroke patients, most of these individuals are admitted to emergency units without MRI facilities. There is a need for an accurate diagnostic tool that rapidly and reliably detects hemorrhage, extent of ischemia, and vessel status and potentially estimates tissue at risk. We sought to determine the diagnostic accuracy of the combination of non-contrast-enhanced CT, CT angiography (CTA), and CTA source images (CTA-SI, showing early parenchymal contrast enhancement) in comparison with a multiparametric stroke MRI protocol in patients with acute stroke within 6 hours after onset. METHODS: Non-contrast-enhanced CT, CTA, stroke MRI including diffusion-weighted imaging (DWI), and MR angiography (MRA) were performed in patients with symptoms of acute stroke within 6 hours after onset. We analyzed infarct volumes on days 1 and 5 as shown on CTA-SI, DWI, and T2-weighted images (Wilcoxon, Mann-Whitney, Spearman tests), estimated the collateral status, and assessed clinical outcome (modified Rankin Scale, Barthel Index, National Institutes of Health Stroke Scale, Scandinavian Stroke Scale). RESULTS: We analyzed the data of 20 stroke patients who underwent CT and MRI scanning within 6 hours (mean, 2.83 and 3.38 hours, respectively). Vessel occlusion was present in 16 of 20 patients. CTA-SI volumes did not differ from DWI volumes (P=0.601). Furthermore, the CTA-SI lesion volumes significantly correlated with the initial DWI lesion volumes (P<0.0001, r=0.922) and with outcome lesion volumes (P=0.013 r=0.736). Patients with poor collaterals experienced infarct growth (P=0.0058) and had a significantly worse clinical outcome (all P<0.012); patients with good collaterals did not (P=0.176). CONCLUSIONS: The combination of non-contrast-enhanced CT (exclusion of intracranial hemorrhage), CTA (vessel status), and early contrast-enhanced CTA-SI (demarcation of irreversible infarct) allows diagnostic assessment of acute stroke with a quality comparable to that of stroke MRI. Furthermore, it is possible to distinguish patients at risk of infarct growth from those who are not according to the collateral status, in analogy with the stroke MRI mismatch concept.

Acute Disease↗