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[en] Purpose: Evaluation of the emphasis of themes pertaining to radiation dose and dose reduction at the Meeting of the German Radiological Society from 1998-2008 in comparison to international data. Materials and Methods: Retrospective analysis of 9440 abstracts with documentation of study presentation character, type of imaging, and examined body region. Abstracts stating radiation dose or primarily dealing with radiation dose/dose reduction were documented. Results were compared with a Pubmed query. Results: The percentage of purely scientific presentations sank in the observation period from 88 to 66%. While contributions dealing with MRI sank from 48 to 34%, those dealing with CT rose from 30 to 34%. The percentage of abstracts dealing with radiation dose rose from 7 to 10%, while that of work primarily pertaining to dose/dose reduction grew from 4 to 6% and 2 to 4%, respectively. Of all abstracts concerning CT, 15% touched on radiation dose, while 9% and 6% primarily dealt with dose and dose reduction. The respective numbers for cardiac CT, whose relative share of all CT abstracts rose from 3% in 1998 to 12% in 2008, were 10%, 7%, and 5%. An online query produced 137,791 publications on CT, and 2% of these abstracts mentioned radiation dose and 0.5% mentioned dose reduction. Conclusion: The number of presentations dealing with dose at the Meeting of the German Radiological Society has risen with time and is higher than the international number. On the other hand, >90% of all presentations and >85% of all CT abstracts do not mention radiation dose. In light of increasing public concern relating to radiation exposure, more intensive research of these themes is warranted. (orig.)
[en] Purpose: Assessment of the knowledge of non-radiological physicians concerning radiation exposure during radiological procedures on the thorax. Material and Methods: 124 non-radiological physicians from the departments of surgery, internal medicine, anesthesiology, and neurology at a university hospital were questioned during a four-week period using a standardized questionnaire as to the effective dose (ED) of different radiological procedures on the thorax. The interviewees were asked to estimate the ED of chest X-rays and CT examinations and to compare these with the ED of other radiological methods. Length of professional experience, field of clinical training, and hierarchical position were also documented. The T-test and chi-square test were used for statistical analysis. Results: 119/124 (96.0 %) physicians with an average work experience of 8.2 years (0.3 - 32 years) were willing to participate. 47/119 (39.5 %) correctly estimated the ED of conventional chest X-ray (0.01 - 0.1 mSv), and 40/119 (33.6 %) correctly gauged the ED of adult chest CT (1 - 10 mSv). The ED of cardiac CT and pediatric chest CT without dose reduction (10 - 100 mSv) were correctly judged by 31/119 (26.1 %) and 32/119 (26.9 %), respectively. The correct ratio of the ED of chest X-ray to that of chest CT (factor 100 - 1000) was given by 28/119 (23.5 %), while 86/119 (72.3 %) underestimated the ratio. 50/119 (42.0 %) and 35/119 (29.4 %) correctly stated that the ED of pediatric chest CT without dose reduction and that of cardiac CT are greater than that of adult chest CT. 24/119 (20.2 %) and 10/119 (8.4 %) thought that the ED of low-dose chest CT is smaller than that of chest X-ray or chest MRI, respectively. The length of professional experience, field of clinical training, and hierarchical position of the participants did not have a significant influence on the test results. (orig.)
[en] Purpose: To evaluate the performance of conventional radiographs (CR) for the assessment of pedicle screws in comparison with CT including MPR. Materials and Methods: Comparison of CR and CT for the evaluation of screw length, extracorporal perforation (grade A: 0 - 2 mm, B: 3 - 4 mm, C: 5 - 6 mm, D: > 6 mm, relevant: grade C and D), screw contact/loosening, and subjective image quality (1: excellent to 4: non-diagnostic). The sensitivity (SE), specificity (SP), positive (PPV) and negative predictive value (NPV), and overall accuracy (OA) were calculated with 4 x 4 contingency tables. The subjective image quality was evaluated using the Wilcoxon test (p < 0.05). Results: 411 screws were evaluated. The relevant medial perforation was diagnosed with CR/CT in 53(13 %)/ 11(3 %) screws, while the relevant lateral perforation was found in 3(1 %)/ 43(11 %) screws. Pedicle screw contact was diagnosed by CR/CT in 10(2 %)/ 18(4 %) cases and incorrect length was confirmed in 80(20 %)/ 90(22 %) screws. A diagnosis of loosening was established in 10(2 %) screws by CR and in 7(2 %) screws by MDCT. In summary, CR demonstrated SE, SP, PPV, NPV, and OA for the following variables: relevant medial perforation = 64 / 89 / 13 / 99 / 88 %, relevant lateral perforation = 4 / 99 / 67 / 90 / 90 %, screw contact = 11 / 98 / 20 / 96 / 94 %, incorrect screw length = 86 / 58 / 89 / 51 / 81 %, and screw loosening = 71 %/ 99 %/ 50 %/ 100 %/ 98 %. The subjective image quality of CR was significantly lower compared to CT (2.19 ± 0.84 and 1.11 ± 0.31; p < 0.001). Conclusion: CR evaluation of pedicle screws following dorsal instrumentation of the spine demonstrated an OA ≤ 90 % for relevant medial and lateral perforation and for incorrect screw length compared to CT. Thus, reliable evaluation of pedicle screws based solely on CR does not seem feasible.
[en] Purpose: Retrospective analysis of vertebral fractures in patients with ankylosing spondylitis (AS) for the evaluation of associations with mortality, concurrent neurological deficits, and other complications. Materials and Methods: Image analysis (conventional radiographs, CT, MRI) was applied to all patients with AS admitted between 1997 and 2007 due to vertebral fractures to determine fracture location and classification. Patient characteristics, trauma mechanism, neurological symptoms, and other complications were documented. Results: 66 patients (54 male, age 64 ± 11 years) were enrolled in the study. 74 % of patients suffered from minor trauma. 51 % and 56 % had cervicothoracic and thoracolumbar fractures, respectively, while 8 % had multi-level fractures. 63 % of patients suffered combined vertebrodiscal fractures. 70 % revealed neurological symptoms, significantly correlating with spinal stenosis (p 0.024; Odds ratio 4.265) and hyperlordosis (p = 0.014; OR 4.806). 68 % developed complications with non-combined fractures (p =.042; OR 4.954) and paravertebral hematomas (p =.009; OR 16.969) representing independent risk factors. The female gender (p = 0.005; OR 15.617) and conservative therapy (p = 0.040; OR.094) exerted significant influence on the mortality rate. Conclusion: Vertebral fractures frequently occur in patients with AS after minor trauma and often lead to neurological symptoms, which in turn are associated with spinal stenosis and hyperlordosis. Paravertebral hematomas and non-combined fractures are accompanied by higher incidences of other complications. The female gender entails a higher mortality rate. (orig.)