Syngo x workplace

The system automatically transferred the acquired data to the workstation (syngo X-Workplace; Siemens Healthcare GmbH, Forchheim, Germany) for postprocessing using commercially available imaging software (syngo Neuro PBV; Siemens AG Healthcare Sector, Germany). PBV reconstruction was visualized in the form of colored multiplanar reconstruction images, in which the pseudocolor corresponded to blood volume. The kidney volume and the mean density of CM of the whole kidney were measured using the syngo volume task card tool. The data of all patients were analyzed by the same engineer from Siemens AG.

All fluoroscopic and C-arm CT data were acquired on a biplane flat-panel detector angiography system (AXIOM Artis or Artis Q biplane, Siemens Healthcare GmbH, Forchheim, Germany). Reconstructions of the C-arm CT images and post-processing of the 3D-DSA images were performed on the system’s workstation (syngo X Workplace, Siemens Healthcare GmbH, Forchheim, Germany). Images were generated with a slice matrix of 256 × 256 (one case 512 × 512), an edge-enhanced reconstruction kernel, and an isotropic voxel size of 0.2–0.4 mm. 3D-DSA image data were acquired at the beginning and end of each procedure. Pre-procedural 3D-DSA images of the aneurysm and parent vessels were used for planning the procedure and selecting the stent. At the end of the procedure, fused images (syngo DualVolume, Siemens Healthcare GmbH, Forchheim, Germany) were used to confirm the coiling, the obliteration of the aneurysm, and the stent placement in the parent artery. These images consisted of non-contrast 3D images (mask images) fused with the 3D-DSA images of the vessels, resulting in 3D-DSA vessel images that included coils and stent markers.

Two experienced neuroradiologists analyzed the MRI datasets on a syngo X-workplace (Siemens, Erlangen, Germany) to allow interactive reconstruction and interpretation. Both raters were blinded for time point and injection information (experimental group versus sham). All major basal cerebral arteries (anterior cerebral artery, middle cerebral artery, internal carotid artery and the basilar artery) were evaluated for the presence of caliber variations indicating VSP. Ischemia was defined as a new hyperintense lesion on T2 weighted MR images. The vessel diameter measurements were performed after reconstruction of the dataset of the TOF-sequence in 3mm MIP. We measured all vessels and, in case of a caliber change, we measured the most severe stenosis of the affected vessel. The median diameter of the internal carotid artery on the MRA on day 1 was 0.7mm, of the anterior cerebral artery, middle cerebral artery and basilar artery 0.6mm. Because we did not perform MRI on day 1 in all rats, we compared the measurements on day 2 and day 5 with the median diameter of the vessels on day 1. For grading the VSP severity, the vessel diameter of these arteries was measured (Fig 1). The baseline data served as reference values for the diagnosis of VSP. A vessel narrowing of 25–50% was classified as mild VSP, of 50–75% as moderate VSP and of >75% as severe VSP.