Julie Rösch

Optimized angiographic computed tomography with intravenous contrast injection: an alternative to conventional angiography in the follow-up of clipped aneurysms?

OBJECT The purpose of this study was to evaluate the diagnostic accuracy of an optimized angiographic CT (ACT) program with intravenous contrast agent injection (ivACT) in the assessment of potential aneurysm remnants after neurosurgical clipping compared with conventional digital subtraction angiography (DSA). METHODS The authors report on 14 patients with 19 surgically clipped cerebral aneurysms who were scheduled to undergo angiographic follow-up. For each patient, the authors performed ivACT with dual rotational acquisition and conventional angiography including a 3D rotational run. The ivACT and 3D DSA data were reconstructed with different imaging modes, including a newly implemented subtraction mode with motion correction. Thereafter, the data sets were merged by the dual-volume technique, and freely rotatable 3D images were obtained for further analysis. Observed aneurysm remnants were electronically measured and classified for each modality by 2 experienced neuroradiologists. RESULTS Digital subtraction angiography and ivACT both provided high-quality images without motion artifacts. Artifact disturbances from the aneurysm clips led to a compromised, but still sufficient, image quality in 1 case. The ivACT assessed all aneurysm remnants as true-positive up to a minimal size of 2.6×2.4 mm in accordance with the DSA findings. There was a tendency for ivACT to overestimate the size of the aneurysm remnants. All cases without aneurysm remnants on DSA were scored correctly as true-negative by ivACT. CONCLUSIONS By using an optimized image acquisition protocol as well as enhanced postprocessing algorithms, the noninvasive ivACT seems to achieve results comparable to those of conventional angiography in the follow-up of clipped cerebral aneurysms. The authors have shown that ivACT can provide reliable diagnostic information about potential aneurysm remnants after neurosurgical clipping with high sensitivity and specificity, sufficient for clinical decision making, at least for aneurysms in the anterior circulation located distal to the internal carotid artery. These preliminary results may be a promising step to replace conventional angiography by a noninvasive imaging technique in selected cases after aneurysm clipping.

Quiet diffusion-weighted head scanning: Initial clinical evaluation in ischemic stroke patients at 1.5T.

To compare the quality and diagnostic value of routine single‐shot, echo‐planar imaging, diffusion‐weighted imaging (ss‐EPI‐DWI) to those of quiet readout segmented EPI‐DWI (q‐DWI) in magnetic resonance imaging (MRI) of acute stroke.

3T-MRI in patients with pharmacoresistant epilepsy and a vagus nerve stimulator: A pilot study

PURPOSE For safe 3T-MRI of patients with VNS (vagus nerve stimulator), specific conditions are mandatory. However, application of these conditions can lead to a loss of image quality. In this work, we evaluated the diagnostic value of 3T-MRI in VNS patients with pharmacoresistant epilepsy. METHODS Using a transmit-and-receive head coil and adapting our sequences to allow for low SAR (specific absorption rate), we examined 15 patients with pharmacoresistant epilepsy. Diagnostic quality was assessed by comparison of the SNR (signal to noise ratio) and CNR (contrast to noise ratio) of the hippocampus, the grey-white matter contrast and epileptogenic lesions to images of patients without VNS acquired with our routine 3T-MRI protocol and the 32-channel head coil. RESULTS 3T-MRI is feasible in VNS-patients. Image quality is adequate for detection and follow-up of epileptogenic lesions such as ganglioglioma or PNH (periventricular nodular heterotopia). Due to a significant reduction of SNR and CNR, the diagnostic value for subtle lesions may be decreased. Overall, the feasibility of 3T-MRI is beneficial in the diagnostic workup and follow-up of epilepsy-patients with VNS.

Are Flow Diverting Stents a Treatment Option in Acutely Ruptured Complex A1-A2 Junction Aneurysms?

1. A 66-year-old woman was presented with clinical signs of acute SAH (Hunt and Hess score 1) proven by lumbar puncture. Initial magnetic resonance imaging (MRI) did not show SAH, but confirmed a partially thrombosed aneurysm of the right A1-A2 junction. Conventional angiography including 3D-reconstruction showed a fusiform appearing aneurysm, with a saccular part being masked by partial thrombosis (Fig. 1). 2. A 58-year-old woman was presented with aphasia and left facial nerve paralysis. MRI showed SAH and was confirmed by lumbar puncture. Furthermore, MRI disclosed a subacute partial left middle cerebral artery stroke caused by vasospasms (Fig. 2). On request, she reported headache and neck pain lasting for a week. During diagnostic angiography, a fusiform multilobulated left A1-A2 junction aneurysm was detected. 3. A 53-year-old man was presented with acute headache and nuchal rigidity (Hunt and Hess score 2). Computed tomography (CT) confirmed significant SAH (Fisher grade IV) and ventricular enlargement. Digital subtraction angiography (DSA) performed after placement of Introduction