Ammar Mallouhi
Vienna Medical University, Austria
Scientific Tracks Abstracts: J Neurol Neurophysiol
Purpose: It has been shown that using variable window width and center level settings facilitates the detection of ischemic brain parenchyma in unenhanced cerebral CT (CCT) by accentuating the contrast between normal and edematous tissue. The aim of this study was to apply color-coded volume rendering to CCT datasets and assess the clinical value of the resulting volume-rendered CCT images in the detection of early infarction signs. Method and Materials: Ethics committee at our institute approved this study. The calculated sample size was 80 patients. Unenhanced CCT datasets of 80 consecutive patients with clinical suspicion of acute stroke were retrospectively evaluated. Utilizing commercially available software, CCT images were reconstructed and a specific color was assigned to each voxel corresponding to its HU value. Two resident doctors, after completion of their neuroradiological training, evaluated source and volume-rendered CCT images. The reference standard was MRI with DWI that proved or ruled out an acute infarction. The diagnostic confidence in the presence of acute brain ischemia was scored by using a 5-point ordinal scale (1, definitely present and 5, definitely absent) and assessed with ROC analysis. Results: All volume-rendered CCT images were of good and diagnostic image quality. On DWI, 57 hyperacute cerebral infarction foci in 43 patients were identified. Volume-rendered CCT images allowed better performance than gray-scale CT images (Az, 0.84 and 0.61, respectively) in detecting early signs of infarction. Mean sensitivity, specificity and accuracy were 79%, 86% and 81%, respectively for volume-rendered images and 53%, 86% and 59%, respectively for source images. Interobserver agreement was substantial for volume-rendered and moderate for gray-scale CT images. Conclusion: Particularly for radiologists in training, color-coded volume-rendered CCT images may facilitate the visualization of ischemic brain parenchyma and augment its diagnostic confidence in the detection of acute stroke.
Ammar Mallouhi has completed his Specialization in diagnostic radiology in Innsbruck, Austria in 2006 and he was awarded a Venia Docendi in 2007 and working as an associate professor in the Department of Neuroradiology at Vienna Medical University in Vienna, Austria since 2010. He has published more than 40 papers and Proceedings in reputed journals and Books. He was awarded with several international scientific awards including three “Certificate of Merit” from the RSNA.
