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Small‐scale heterogeneities within the seafloor such as glacial boulders, concretions, or unexploded ordnance are of major scientific and economic interest. Because of their small size, such objects are hardly imageable by conventional seismic methods since they produce only faint diffractions. Despite the growing interest, reliable and efficient object detection methods are still not established. So, a marine acquisition system to image objects in the size range 0.3–4.1 m in the near‐surface has been designed and workflows have been developed. Source signals with a central frequency of ∼1,000 Hz are necessary to generate diffractions for the object size range. Performing beam pattern analyses, a rigid tow frame with the dimensions 8 × 3 m and attached hydrophones was designed. A synthetic aperture approach is realized to improve the resolution. Reflection events are suppressed in Normal‐Move‐Out corrected shot gathers by the muting of high singular values to enhance the diffractions. The diffractions are imaged with a beamforming algorithm with a high efficiency, as a total swath angle of about 80° in across‐track direction is covered. The processing of synthetic data sets allows an optimization and validation of the workflow and sensitivity analyses. Ground truthing is achieved with 1–2 m large boulders on the seafloor in 22 m depth, which were identified in a Multi‐Beam Echo Sounder data set. Although diffractions are only weak events in seismic data sets, 3D object detection with seismic beamforming has been found to be an efficient and reliable method to perform derisking for offshore infrastructure installations, drillings, or geologic interpretation. Plain Language Summary: Buried glacial boulders and other small, nonferrous objects like unexploded ordnance are hardly detected with standard geophysical methods. However, those objects are of special relevance being indicators for glacial processes and posing risks for infrastructure installations. So, we designed a marine acquisition system and a processing scheme to exploit the seldom used diffracted wavefield of a seismic record. The system includes a sound source emitting an acoustic signal with a dominant frequency of 1,000 Hz to the water, a rigid tow frame of 8 × 3 m with attached underwater sound recorders and 3D positioning. As a first step, the digital data processing aims to enhance the diffractions, which are the waves scattered by small‐scale objects. Second, beamforming is used to detect the objects building on the constructive interference of the sound recorded and combined at calculated time shifts. As a swath of the seafloor greater than twice the depth of the water can be investigated in a single pass, our proposed method is very efficient. In this study, we show the development and validation of the method with computer models. Also, the practical feasibility is proven with the detection of 1–2 m large boulders on the seafloor of the North Sea in about 20 m depth. Key Points: Ultra‐High Resolution seismic data beamforming is used to perform efficient 3D diffraction imaging in the near‐surface including ground truthingBoulders and other small‐scale objects in the sub‐seafloor can be detected by diffraction imagingDensely spaced receivers on a rigid frame for accurate positioning and an Ultra‐High Resolution seismic source are proposed for acquisition [ABSTRACT FROM AUTHOR]

PURPOSE OF THE STUDY Pelvic trauma causes severe threats especially to polytraumatized patients. Not only it is in itself a possible cause for significant bleeding, but it also indicates a high risk for intra-abdominal injuries. The initial treatment of patients with pelvic trauma follows the ATLS principles of priority-oriented treatment. To examine the value of this highly standardized concept and to evaluate the effect of different patient collectives on early outcome parameters, two large collectives from Germany and Qatar were analyzed regarding injury parameters and early outcomes. MATERIAL AND METHODS Patients were recruited in Hamad General Hospital, Doha, Qatar (HGH) and BG Trauma Center Ludwigshafen, Germany (BG). All patients that were treated with a pelvic fracture between 2013 and 2016 were included in this retrospective analysis. Demographic parameters were collected as well as type of injury and the frequency of complication parameters as pneumonia, acute kidney failure, ARDS, sepsis and amount of blood transfusion. 1436 patients with pelvic fracture (645 from BG and 791 from HGH) were recruited. The mean age was 57.4 years in the BG and 33.6 years in the HGH group (p<0.000). The mean ISS was 17.81 in the BG and 15.88 in the HGH group (p=0.009). The mean pelvic AIS was 2.65 in the BG and 2.25 in the HGH group (p<0.000). RESULTS The mean frequency of complications was 9.3% in the BG and 9.9% in the HGH group (p=0.128). The mean frequency of ARDS was significantly higher in the BG group than in the HGH group (5.6% vs. 1.8%, p<0.000). The mean frequency of blood transfusion was significantly lower in the BG group than in the HGH group (28.8% vs. 39.2%, p<0.000). CONCLUSIONS Despite significant differences in the two collectives, this analysis shows comparable results regarding early outcome parameters in patients with pelvic injuries. In total, pelvic injuries are accompanied by a relatively high complication risk and need to be evaluated and treated according to priority-based algorithms. [ABSTRACT FROM AUTHOR]

Background: Navigational techniques in orthopaedic trauma surgery have developed over the last years leaving the question of really improving quality of treatment. Especially in marginal surgical indications, their benefit has to be evident. The aim of this study was to compare reduction and screw position following 3D-navigated and conventional percutaneous screw fixation of acetabular fractures. The study hypothesis postulated that better fracture reduction and better screw position are obtained with 3D navigation. Materials and methods: Preoperative and postoperative CT scans of 37 acetabular fractures treated by percutaneous screw fixation (24 3D-navigated, 13 conventional) were evaluated. Differences in pre- and postoperative fracture gaps and steps were compared in all reconstructions as well as the screw position relative to the joint and the fracture. Results: The differences in fracture gaps and fracture steps with and without 3D navigation were not significantly different. Distance of the screw from the joint line, angle difference between screw and ideal angle relative to the fracture line, length of the possible corridor used and position of the screw thread did not show any significant differences. Conclusion: Comparison of 3D-navigated and conventional percutaneous surgery of acetabular fractures on the basis of pre- and postoperative CTs revealed no significant differences in terms of fracture reduction and screw position. [ABSTRACT FROM AUTHOR]

Anatomic reconstruction of articular fractures is one of the critical factors in later achieving good functional outcome. Intraoperative 3D imaging has been shown to offer better evaluation and therefore can significantly improve the results. The purpose of this study was to assess the difference between intraoperative three-dimensional fluoroscopy (3D) and intraoperative computed tomography (iCT) imaging regarding fracture reduction, implant placement and articular impressions in a distal humeral fracture model. AO type 13-B2 fracture pattern were created in upper extremity cadaver specimens. Articular step-offs, intra-articular screw placement and intraarticular impressions of different degrees of severity were created. All specimens had imaging performed. For each articular pattern 3D fluoroscopy in standard (3Ds) and high quality (3Dh) were performed (Arcadis Orbic, Siemens, Germany) as well as an intraoperative CT scan (iCT, Airo, Brainlab, Germany). Three observers evaluated all imaging studies regarding subjective and objective parameters. iCT is more precise than 3D fluoroscopic imaging for detection of articular impressions. Articular step-offs and intraarticular screw placement are similar for iCT and 3D. Subjective imaging quality is the highest for iCT and lowest for 3Ds. Intraoperative CT may be particularly useful in assessing articular impressions and providing a good subjective image quality for the surgeon. [ABSTRACT FROM AUTHOR]

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Copyright of Der Unfallchirurg is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Patients who died of a melanoma thinner than 1.5mm within 96 months (group 1, n=60) were compared with those having a tumor of the same thickness who had not died in this time period (Group 2, n=300). Both groups were investigated with respect to differences in patients sex and age and to thickness, diameter, exophytic growth, and site of the melanoma as well as the number of mitoses/mm of tumor area. Relatively speaking, more men than women died of a thin melanoma: in Group 1 (deceased) there were 32 men and 28 women, in Group 2 (alive) 58 men and 242 women. The better survival rate of females did not depend on the difference in the predominating melanoma locations (♀face and legs; ♂ trunk): in both sites, on the legs and on the trunk, women had a significantly higher 8-year survival rate than men with equally thick tumors. Furthermore, melanomas on the arms and legs of females had a better prognosis than those on the trunk and face. Both the patient's sex and the tumor site seem to influence the survival of melanoma patients. Only in men was the median of mitoses/mm of tumor area found to be higher in the first group (2.2) than in the second group (0.75). In women, no marked difference in the mitotic count was found (Group 1:1.1; Group 2:1.15). [ABSTRACT FROM AUTHOR]