@article{LinsenmannMaerzDufneretal.2021,
  author    = {Linsenmann, Thomas and M{\"a}rz, Alexander and Dufner, Vera and Stetter, Christian and Weiland, Judith and Westermaier, Thomas},
  title     = {Optimization of radiation settings for angiography using 3D fluoroscopy for imaging of intracranial aneurysms},
  series = {Computer Assisted Surgery},
  volume    = {26},
  journal   = {Computer Assisted Surgery},
  number    = {1},
  doi       = {10.1080/24699322.2021.1894240},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259251},
  pages     = {22-30},
  year      = {2021},
  abstract  = {Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. We recently reported its use for imaging cerebral vascular malformations and aneurysms. This study was conducted to evaluate various radiation settings for the imaging of cerebral aneurysms before and after surgical occlusion. Eighteen patients with cerebral aneurysms with the indication for surgical clipping were included in this prospective analysis. Before surgery the patients were randomized into one of three different scan protocols according (default settings of the 3D fluoroscope): Group 1: 110 kV, 80 mA (enhanced cranial mode), group 2: 120 kV, 64 mA (lumbar spine mode), group 3: 120 kV, 25 mA (head/neck settings). Prior to surgery, a rotational fluoroscopy scan (duration 24 s) was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac(R) workstation, subtracted and reconstructed using OsiriX(R) MD 10.0 software. The procedure was repeated after clip placement. The image quality regarding preoperative aneurysm configuration and postoperative assessment of aneurysm occlusion and vessel patency was analyzed by 2 independent reviewers using a 6-grade scale. This technique quickly supplies images of adequate quality to depict intracranial aneurysms and distal vessel patency after aneurysm clipping. Regarding these features, a further optimization to our previous protocol seems possible lowering the voltage and increasing tube current. For quick intraoperative assessment, image subtraction seems not necessary. Thus, a native scan without a contrast agent is not necessary. Further optimization may be possible using a different contrast injection protocol.},
  language  = {en}
}
@article{WestermaierLinsenmannHomolaetal.2016,
  author    = {Westermaier, Thomas and Linsenmann, Thomas and Homola, Gy{\"o}rgy A. and Loehr, Mario and Stetter, Christian and Willner, Nadine and Ernestus, Ralf-Ingo and Soymosi, Laszlo and Vince, Giles H.},
  title     = {3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms - assessment of feasibility and image quality},
  series = {BMC Medical Imaging},
  volume    = {16},
  journal   = {BMC Medical Imaging},
  number    = {30},
  doi       = {10.1186/s12880-016-0133-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146381},
  year      = {2016},
  abstract  = {Background Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms. Materials and methods Twelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency. Results Image acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants. Conclusion This technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.},
  language  = {en}
}