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Assessment of the cochlear implant (CI) electrode array position using flat-detector computed tomography (FDCT) to test dependence of postoperative outcome on intracochlear electrode position.A total of 102 patients implanted with 107 CIs underwent FDCT. Electrode position was rated as 1) scala tympani, 2) scala vestibuli, 3) scalar dislocation and 4) no deconvolution. Two independent neuroradiologists rated all image data sets twice and the scalar position was verified by a third neuroradiologist. Presurgical and postsurgical speech audiometry by the Freiburg monosyllabic test was used to evaluate auditory outcome after 6 months of speech rehabilitation.Electrode array position was assessed by FDCT in 107 CIs. Of the electrodes 60 were detected in the scala tympani, 21 in the scala vestibuli, 24 electrode arrays showed scalar dislocation and 2 electrodes were not placed in an intracochlear position. There was no significant difference in rehabilitation outcomes between scala tympani and scala vestibuli inserted patients. Rehabilitation was also possible in patients with dislocated electrodes.The use of FDCT is a reliable diagnostic method to determine the position of the electrode array. In our study cohort, the electrode position had no significant impact on postoperative outcome except for non-deconvoluted electrode arrays.

In 3D digital subtraction angiography, the propagation of iodine-based contrast agent in cerebral vessels implies a delayed enhancement of soft tissue, i.e. parenchyma, which causes inconsistencies across the acquired projection images that impair the quality of the reconstructed volumes. In order to cope with this issue, we perform an estimation of contrast-enhanced parenchyma in projection images. The estimation is based on a vessel segmentation and an iterative interpolation of segmented vessel pixels. The estimated parenchyma is subsequently separated from the projection images. Thus, only contrast-enhanced vessels remain and data inconsistencies due to late-enhancing parenchyma will be reduced. The method is applied to two datasets of cerebral vasculatures. The image series are compared prior and post to parenchyma subtraction. Reconstructed volumes show minor noise in background voxels. An average increase of 37% in signal-to-noise ratio is achieved.

In C-arm CT 3D liver imaging, breathing leads to motion artifacts due to the relatively long acquisition time. Often, even with breath-holding residual respiratory motion can be observed. These artifacts manifest in blurring and interfere clinical investigations such as liver tissue imaging. For 3D medical image reconstruction a respiratory motion estimation and compensation is required. In this work, the motion was estimated by tracking the motion of the diaphragm and of a vessel bifurcation. The motion signals were integrated into a Thin-Plate-Spline that was used for intra-scan motion compensated reconstruction. This approach was applied to clinical C-arm CT data of the liver and showed improved image quality. Reduced artifacts allow a more precise visual depiction of the liver tissue for liver imaging.

In current clinical practice, examinations of the carotid artery bifurcation are commonly carried out with Computed Tomography Angiography,(CTA) or contrast-enhanced Magnetic Resonance Angiography (ce, MRA). Quantitative information about vessel morphology, extracted from segmentations, is promising for diagnosis of vessel pathologies. However, both above-mentioned techniques require the administration of contrast media. In contrary, non-ce MRA methods such as Time-of-Flight,(TOF) provide fully non-invasive imaging without any exogenous contrast agent. The diagnostic value of TOF MRA, however, for assessment of the carotid bifurcation area can be hampered due to its susceptibility to irregular blood flow patterns. Conventional methods for lumen segmentation are very sensitive to such signal voids and produce inaccurate results. In this work, a novel, fully automatic 3D segmentation algorithm is proposed which uses prior knowledge about irregular flow patterns. The presented technique has been successfully tested on eleven volunteer datasets as well as in a patient case, offering the comparison to CTA images. The sensitivity could be increased by 29.2% to 85.6% compared to standard level set methods. The root mean squared error in diameter measurements was reduced from 4.85,mm to 1.44,mm.

The unfavorable application-to-tumor-dose-ratio is a drawback of conventional systemic chemotherapy, implying an often insufficient drug dose in the tumor being associated with severe side effects for the patient. The use of chemotherapeutics bound to magnetic nanoparticles offers several advantages. On the one hand it is possible to concentrate the chemotherapeutics in the tumor region by the use of magnetic fields, like it is done in Magnetic Drug Targeting (MDT). On the other hand magnetic particles can serve as contrast agent for magnetic resonance imaging (MRI) that is bound to the therapeutics. Hence, the particles possibly are opening an insight into drug distribution in the tumor region directly after administration.

Glaucoma is associated with axonal degeneration of the optic nerve leading to visual impairment. This impairment can progress to a complete vision loss. The transsynaptic disease spread in glaucoma extends the degeneration process to different parts of the visual pathway. Most of glaucoma diagnosis focuses on the eye analysis, especially in the retina. In this work, we propose a system to classify glaucoma based on visual pathway analysis. The system utilizes diffusion tensor imaging to identify the optic radiation. Diffusion tensor-derived indices describing the underlying fiber structure as well as the main diffusion direction are used to characterize the optic radiation. Features are extracted from the histograms of these parameters in regions of interest defined on the optic radiation. A support vector machine classifier is used to rank the extracted features according to their discrimination ability between glaucoma patients and healthy subjects. The seven highest ranked features are used as inputs to a logistic regression classifier. The system is applied to two age-matched groups of 39 glaucoma subjects and 27 normal controls. The evaluation is performed using a 10-fold cross validation scheme. A classification accuracy of 81.8% is achieved with an area under the ROC curve of 0.85. The performance of the system is competitive to retina based classification systems. However, this work presents a new direction in detecting glaucoma using visual pathway analysis. This analysis is complementary to eye examinations and can result in improvements in glaucoma diagnosis, detection, and treatment.

LA: beginnende glaukomatose Optikusatrophie mit V.a. Nervenfaserdefekt bei 5 h V.a. Normaldruckglaukom; RA: eher vitale Papille Keine Voroperationen Negative Familienanamnese bezuglich Glaukomerkrankung T: RA 16 mmHg appl.; LA 17 mmHg appl. T max.: RA 25 mmHg; LA 24 mmHg Visus: RA sc = 0,6 p; ccs = 1,25 p; LA sc = 0,7 p; ccs = 1,25 p Papillenflache: RA 1,8 mm2, LA 1,9 mm2 Pachymetrie der Hornhaut: RA 535 µm; LA 530 µm Arterielle Hypertonie: Therapie mit Metoprolol und Ramipril Zentralfeld-Schwellentest: fleckformige Gesichtfeldausfalle beidseits temporal W-w-Perimetrie (Mean Defect): RA -1,0 dB; LA 3,0 dB Frequency Doubling Technique (FDT): Dauer: RA 38 sec; LA 41 sec, Klassifikation: normal kraniale 3-Tesla-Kernspin-Untersuchung (MRI): masig ausgepragte globale Mikroangiopathie, Zeichen einer Mikroangiopathie in der Sehstrahlung kraniale 3-Tesla-Kernspin-Untersuchung (Diffusion Tensor Imaging [DTI] mit Darstellung der Sehbahn): beidseits grenzwertig schmachtige Sehstrahlung

CBT („Computer-basiertes Training“) verfolgt die unmittelbare Verknupfung von Video- und Audiosequenzen, Bilddarstellungen und Texten auf CD-ROM und den jederzeitigen Zugriff auf einzelnen Multimediakomponenten (MMK). Auf der vorliegenden CD-ROM werden auf ca. 200 Informationskarten alle Aspekte der Carotis-Chirurgie behandelt. Besondere Beachtung findet die Vermittlung operativ-technischer Details, die auf 60 Minuten Videofilm und ca. 250 Bilddarstellungen erfolgt. Insgesamt last die Entwicklung von CBT-Modulen eine Verbesserung und Intensivierung der (gefas)chirurgischen Aus- und Weiterbildung, des Studenten-Unterrichts und/oder eine lernfreundlichere Form der Wissensvermittlung erwarten.

Bei 56 Patienten wurde im Median 14 Tage nach einem nicht-invalidisierenden Schlaganfall eine Carotis-TEA mit einer perioperativen Minor-Apoplexrate von 3,6% durchgefuhrt. Auch grosere Infarkte im CCT waren kein Ausschluskriterium, sofern die Patienten sich neurologisch gebessert hatten („neurologisches Plateau“). Unsere Daten deuten darauf hin, das die fruhe Carotis-TEA (