Fleischhammer, Julius

[["dc.bibliographiccitation.artnumber","E13"],["dc.bibliographiccitation.firstpage","E13"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Neurosurgical Focus"],["dc.bibliographiccitation.volume","42"],["dc.contributor.author","Solomiichuk, Volodymyr"],["dc.contributor.author","Fleischhammer, Julius"],["dc.contributor.author","Molliqaj, Granit"],["dc.contributor.author","Warda, Jwad"],["dc.contributor.author","Alaid, Awad"],["dc.contributor.author","von Eckardstein, Kajetan"],["dc.contributor.author","Schaller, Karl"],["dc.contributor.author","Tessitore, Enrico"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Schatlo, Bawarjan"],["dc.date.accessioned","2020-12-10T18:44:04Z"],["dc.date.available","2020-12-10T18:44:04Z"],["dc.date.issued","2017"],["dc.description.abstract","OBJECTIVE Robot-guided pedicle screw placement is an established technique for the placement of pedicle screws. However, most studies have focused on degenerative disease. In this paper, the authors focus on metastatic spinal disease, which is associated with osteolysis. The associated lack of dense bone may potentially affect the automatic recognition accuracy of radiography-based surgical assistance systems. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement for thoracolumbar metastatic spinal disease. METHODS Seventy patients with metastatic spinal disease who required instrumentation were included in this retrospective matched-cohort study. All 70 patients underwent surgery performed by the same team of experienced surgeons. The decision to use robot-assisted or fluoroscopy-guided pedicle screw placement was based the availability of the robot system. In patients who underwent surgery with robot guidance, pedicle screws were inserted after preoperative planning and intraoperative fluoroscopic matching. In the \"conventional\" group, anatomical landmarks and anteroposterior and lateral fluoroscopy guided placement of the pedicle screws. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale. Grades A and B (<2-mm pedicle breach) were considered clinically acceptable, and all other grades indicated misplacement. Secondary outcome measures included an intergroup comparison of direction of screw misplacement, surgical site infection, and radiation exposure. RESULTS A total of 406 screws were placed at 206 levels. Sixty-one (29.6%) surgically treated levels were in the upper thoracic spine (T1-6), 74 (35.9%) were in the lower thoracic spine, and the remaining 71 (34.4%) were in the lumbosacral region. In the robot-assisted group (Group I; n = 35, 192 screws), trajectories were Grade A or B in 162 (84.4%) of screws. The misplacement rate was 15.6% (30 of 192 screws). In the conventional group (Group II; n = 35, 214 screws), 83.6% (179 of 214) of screw trajectories were acceptable, with a misplacement rate of 16.4% (35 of 214). There was no difference in screw accuracy between the groups (chi-square, 2-tailed Fisher's exact, p = 0.89). One screw misplacement in the fluoroscopy group required a second surgery (0.5%), but no revisions were required in the robot group. There was no difference in surgical site infections between the 2 groups (Group I, 5 patients [14.3%]; Group II, 8 patients [22.9%]) or in the duration of surgery between the 2 groups (Group I, 226.1 +/- 78.8 minutes; Group II, 264.1 +/- 124.3 minutes; p = 0.13). There was also no difference in radiation time between the groups (Group I, 138.2 +/- 73.0 seconds; Group II, 126.5 +/- 95.6 seconds; p = 0.61), but the radiation intensity was higher in the robot group (Group I, 2.8 +/- 0.2 mAs; Group II, 2.0 +/- 0.6 mAs; p < 0.01). CONCLUSIONS Pedicle screw placement for metastatic disease in the thoracolumbar spine can be performed effectively and safely using robot-guided assistance. Based on this retrospective analysis, accuracy, radiation time, and post-operative infection rates are comparable to those of the conventional technique."],["dc.identifier.doi","10.3171/2017.3.FOCUS1710"],["dc.identifier.eissn","1092-0684"],["dc.identifier.isi","000400609800017"],["dc.identifier.pmid","28463620"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/78315"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Amer Assoc Neurological Surgeons"],["dc.relation.issn","1092-0684"],["dc.title","Robotic versus fluoroscopy-guided pedicle screw insertion for metastatic spinal disease: a matched-cohort comparison"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","428"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Investigative Radiology"],["dc.bibliographiccitation.lastpage","433"],["dc.bibliographiccitation.volume","52"],["dc.contributor.author","Merrem, Andreas"],["dc.contributor.author","Hofer, Sabine"],["dc.contributor.author","Voit, Dirk"],["dc.contributor.author","Merboldt, K.-Dietmar"],["dc.contributor.author","Klosowski, Jakob"],["dc.contributor.author","Untenberger, Markus"],["dc.contributor.author","Fleischhammer, Julius"],["dc.contributor.author","Frahm, Jens"],["dc.date.accessioned","2020-12-10T18:20:12Z"],["dc.date.available","2020-12-10T18:20:12Z"],["dc.date.issued","2017"],["dc.description.abstract","Objective: The aim of this study was to develop a rapid diffusion-weighted (DW) magnetic resonance imaging (MRI) technique for whole-brain studies without susceptibility artifacts and measuring times below 3 minutes. Materials and Methods: The proposed method combines a DWspin-echo module with a single-shot stimulated echo acquisition mode MRI sequence. Previous deficiencies in image quality due to limited signal-to-noise ratio are compensated for (1) by radial undersampling to enhance the flip angle and thus the signal strength of stimulated echoes; (2) by defining the image reconstruction as a non-linear inverse problem, which is solved by the iteratively regularized Gauss-Newton method; and (3) by denoising with use of a modified nonlocal means filter. The method was implemented on a 3 TMRI system(64-channel head coil, 80 mT . m gradients) and evaluated for 10 healthy subjects and 2 patients with an ischemic lesion and epidermoid cyst, respectively. Results: High-quality mean DW images of the entire brain were obtained by acquiring 1 non-DW image and 6 DW images with different diffusion directions at b = 1000 s . mm. The achievable resolution for a total measuring time of 84 seconds was 1.5 mm in plane with a section thickness of 4 mm (55 sections). A measuring time of 168 seconds allowed for an in-plane resolution of 1.25 mm and a section thickness of 3 mm (54 sections). Apparent diffusion coefficient values were in agreement with literature data. Conclusions: The proposed method for DWMRI offers immunity against susceptibility problems, high spatial resolution, adequate signal-to-noise ratio and clinically feasible scan times of less than 3 minutes for whole-brain studies. More extended clinical trials require accelerated computation and online reconstruction."],["dc.identifier.doi","10.1097/RLI.0000000000000357"],["dc.identifier.isi","000403234600006"],["dc.identifier.issn","0020-9996"],["dc.identifier.pmid","28151734"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/75482"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1536-0210"],["dc.relation.issn","0020-9996"],["dc.title","Rapid Diffusion-Weighted Magnetic Resonance Imaging of the Brain Without Susceptibility Artifacts"],["dc.title.subtitle","Single-Shot STEAM With Radial Undersampling and Iterative Reconstruction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]