Entwicklung einer performanten Volume Rendering Komponente für das Operationsplanungssystem MOPS 3D

Computergestützte Planung von chirurgischen Eingrien gehört in der heutigen Zeit zum klinischen Alltag. Besonders in der Neurochirurgie ist ein hohes Maÿ an Präzision erforderlich, so dass es hilfreich ist, die räumlichen Gegebenheiten des individuellen Gehirns, die für die Operation von Bedeutung sind, schon im Voraus zu kennen. MOPS 3D ist ein Operationsplanungssystem, das imstande ist, verschiedene medizinische Bilddaten einzulesen und dem Chirurgen eine dreidimensionale Darstellung des Körperinneren zu präsentieren. Statt mit der herkömmlichen Oberflächendarstellung kann dieses seit Kurzem auch mit Hilfe von Volumenvisualisierung (Volume Rendering) dargestellt werden, da das Volume Rendering Framework Voreen prototypisch in MOPS 3D integriert wurde. In der nachfolgenden Arbeit wird diese prototypische Integration auf Schwachstellen im Verhalten und auf Verbesserungspotential von Performanz und Stabilität untersucht. Danach werden entsprechende Verbesserungen und funktionale Neuerungen konzipiert und in der Volume Rendering Komponente implementiert

Capillary Transit Time Heterogeneity Is Associated with Modified Rankin Scale Score at Discharge in Patients with Bilateral High Grade Internal Carotid Artery Stenosis.

BACKGROUND AND PURPOSE:Perfusion weighted imaging (PWI) is inherently unreliable in patients with severe perfusion abnormalities. We compared the diagnostic accuracy of a novel index of microvascular flow-patterns, so-called capillary transit time heterogeneity (CTH) to that of the commonly used delay parameter Tmax in patients with bilateral high grade internal carotid artery stenosis (ICAS). METHODS:Consecutive patients with bilateral ICAS ≥ 70%NASCET who underwent PWI were retrospectively examined. Maps of CTH and Tmax were analyzed with a volumetric approach using several thresholds. Predictors of favorable outcome (modified Rankin scale at discharge 0-2) were identified using univariate and receiver operating characteristic (ROC) curve analysis. RESULTS:Eighteen patients were included. CTH ≥ 30s differentiated best between patients with favorable and unfavorable outcome when both hemispheres were taken into account (sensitivity 83%, specificity 73%, area under the curve [AUC] 0.833 [confidence interval (CI) 0.635; 1.000]; p = 0.027). The best discrimination using Tmax was achieved with a threshold of ≥ 4s (sensitivity 83%, specificity 64%, AUC 0.803 [CI 0.585;1.000]; p = 0.044). The highest AUC was found for left sided volume with CTH ≥ 15s (sensitivity 83%, specificity 91%, AUC 0.924 [CI 0.791;1.000]; p = 0.005). CONCLUSION:The study suggests that CTH is superior to Tmax in discriminating ICAS patients with favorable from non-favorable outcome. This finding may reflect the simultaneous involvement of large vessels and microvessels in ICAS and underscore the need to diagnose and manage both aspects of the disease

Tmax and CTH maps for three patients.

<p>Each row shows the most representative images of one patient. The first column depicts Tmax, the second CTH maps. Color-coded bars show Tmax and CTH values in seconds, respectively. The first patient (a, b) had perfusion abnormalities in the same region for Tmax and CTH with differing parts of that region being most severely affected. The second patient (c, d) shows a severe Tmax restriction while only slightly elevated CTH values can be seen. In the third patient (e, f) the profile for both Tmax and CTH seems to be comparable in the anterior and posterior middle cerebral artery border zone, while it is different in the temporoparietal region.</p

Parameters of ROC-curve (AUC, standard error, CI) and univariate analysis (in median and [IQR]) for all perfusion parameters with significant differences.

<p>Parameters of ROC-curve (AUC, standard error, CI) and univariate analysis (in median and [IQR]) for all perfusion parameters with significant differences.</p

Additional file 1: Figure S1. of Time-dependent parameter of perfusion imaging as independent predictor of clinical outcome in symptomatic carotid artery stenosis

CT Angiography of the patient shown in Fig. 2. (TIF 1426 kb

Contributions to the development of a multi-stage flash/fluidized bed evaporator (msf/fbe)

Mechanical Maritime and Materials Engineerin