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1.
The initial reports on radiologic examinations in 618 consecutive patients with midfacial injuries were compared with the final clinical diagnoses. Alcohol had to some degree been imbibed by 31 per cent of the patients. Influence of alcohol was 3 times more common outside than within office hours. Radiographic analysis included estimation of blurring, errors in straightness, angulation, beam centering and limitation. Image quality was scored as visibility of 'the imaginary lines of bony continuity'. There was no statistically significant correlation between the degree of inebriety and image quality or diagnostic performance with the radiographic technique used, with the patient supine. There is no need to postpone midfacial radiography in inebriate patients.  相似文献   

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OBJECTIVE: To compare the clinical effectiveness of computed tomography (CT) with conventional radiography in midfacial fractures. METHODS: The conventional radiographs (CM) and CT scans of 40 consecutive patients with complex midfacial fractures were assessed independently by two examiners. The number and site of fractures of the orbit, zygoma and maxilla were compared by the Wilcoxon Matched Pairs Signed Rank test. The best method for classification of the fracture was determined. RESULTS: Coronal CT (CCT) proved superior in the diagnosis of orbital fractures (P<0.001). There was no significant difference between any of the imaging methods for fractures of the zygoma. Axial CT (ACT) was the most effective method in imaging of maxillary fractures (ACT-CM; P<0.001, ACT-CCT; P<0.01). CCT was the most useful in classification of orbital and maxillary fracture. CONCLUSION: CCT is superior to CM for the assessment of complex midface fractures  相似文献   

4.
The physical characteristics of a direct amorphous Selenium (a-Se) digital fluoroscopy and radiography system were investigated. Pre-sampled modulation transfer functions (MTF) were measured using a slit method. Noise power spectra were determined for different input exposures by fast Fourier transform of uniformly exposed samples. The MTFs of direct digital radiography systems showed significantly higher values than those of indirect digital radiography and screen-film systems. The direct digital radiography systems showed higher noise levels compared with those of indirect systems under roughly the same exposure conditions. Contrast-detail analysis was performed to compare detection by direct digital radiography systems with that of the screen-film (FUJI HG-M2/UR2) systems. The average contrast-detail curves of digital and film images were obtained from the results of observation. Image quality figures (IQF) were also calculated from the individual observer performance tests. The results indicated that digital contrast-detail curves and IQF are, on average, are equal those of the screen-film system.  相似文献   

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The purpose of this retrospective study was to intra-individually compare the image quality of computed radiography (CR) and low-dose linear-slit digital radiography (LSDR) for supine chest radiographs. A total of 90 patients (28 female, 62 male; mean age, 55.1 years) imaged with CR and LSDR within a mean time interval of 2.8 days ± 3.0 were included in this study. Two independent readers evaluated the image quality of CR and LSDR based on modified European Guidelines for Quality Criteria for chest X-ray. The Wilcoxon test was used to analyse differences between the techniques. The overall image quality of LSDR was significantly better than the quality of CR (9.75 vs 8.16 of a maximum score of 10; p < 0.001). LSDR performed significantly better than CR for delineation of anatomical structures in the mediastinum and the retrocardiac lung (p < 0.001). CR was superior to LSDR for visually sharp delineation of the lung vessels and the thin linear structures in the lungs. We conclude that LSDR yields better image quality and may be more suitable for excluding significant pathological features of the chest in areas with high attenuation compared with CR.  相似文献   

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Image processing is a critical part of obtaining high-quality digital radiographs. Fortunately, the user of these systems does not need to understand image processing in detail, because the manufacturers provide good starting values. Because radiologists may have different preferences in image appearance, it is helpful to know that many aspects of image appearance can be changed by image processing, and a new preferred setting can be loaded into the computer and saved so that it can become the new standard processing method.Image processing allows one to change the overall optical density of an image and to change its contrast. Spatial frequency processing allows an image to be sharpened, improving its appearance. It also allows noise to be blurred so that it is less visible. Care is necessary to avoid the introduction of artifacts or the hiding of mediastinal tubes.  相似文献   

7.
The large difference in transmission between the mediastinum and the part of the chest mainly containing lungs causes major problems in chest radiography. A system for advanced multiple beam equalization radiography has been evaluated. Evaluation of image quality has been performed both using standard phantoms and from clinical radiographs. Measurements of radiation dose burden to the patient have been made both in clinical examinations and using an anthropomorphic phantom. The image quality, in areas with low transmission, is substantially increased using the equalization system. In parts of the chest mainly containing lung tissue, conventional systems show an equal or slightly better image quality. The radiation dose burden to the patient is increased by 25 percent using the equalization system, as compared to a low-dose air-gap system. In our opinion, the slight increase in radiation dose burden is well motivated by the high overall quality of the radiographs produced.  相似文献   

8.
In a retrospective approach the medical records and radiographs of 618 patients with midfacial trauma were reviewed by radiologists who were classified into four groups according to the length of their training and experience. Initially reported diagnoses were compared with discharge diagnoses, and the impact of training and experience on diagnostic performance was assessed. The same parameters were also investigated in a prospective study. Neither of the investigations revealed any statistically significant improvement in diagnostic performance with increased training and experience. After the basic radiologic education, innate perceptive and cognitive abilities seem to have a larger influence on radiologic diagnostic performance than training and experience.  相似文献   

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Image quality in radiography of middle face trauma was compared within and outside office hours on the basis of the visibility of diagnostically important structures, and an evaluation of the major patient- and technician-related factors influencing image quality. Image quality was statistically significantly better within than outside office hours. This was due to the technician-related factors of patient positioning, X-ray beam limiting and centering. Since the analysis of variance revealed that alcohol intoxication (three times more common outside than within office hours) had no statistically significant effect on image quality, the difference must have been due to the only remaining variable--radiologist supervision, which was present only within office hours.  相似文献   

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This is a report on the testing of a novel system of radiography of the thorax consisting of a combination of moving-slit radiography with a slot-type image intensifier (proximity focussed linear image intensifier), being thus a variant of rotational scanography (or a swinging slot x-ray machine), the image scale being 1:1. The system was compared with conventional x-ray film/foil technique using a group of 115 patients. Special features of the new system are a very low irradiation exposure dose and a 100 x 100 mm size image. It is shown that the imaging method is highly efficient in respect of the examined nine classes of findings and that the image quality of large-size thorax x-ray films is very nearly attained. The low exposure dose, low running cost and advantages in storing and indexing can serve as counter-arguments against the well-known reserved attitude in respect of a medium-size format. The system opens good future possibilities especially with regard to follow-up and monitoring of selected patient groups (e.g. blood donors, medical personnel).  相似文献   

11.
计算机摄影在胸部创伤中的临床应用   总被引:3,自引:1,他引:2  
胸部创伤是临床上常见的胸外科疾病,包括肋骨骨折、气胸、血胸、血气胸及肺挫伤等。X线胸片对胸部创伤的各种改变大都能够显示,但传统X线胸片易受投照因素的影响,其清晰度及对比度较差,某些胸部外伤病变例如肋骨骨折,特别是膈下肋骨容易漏诊,而CR是数字化摄影,其图像可以调节,对胸部创伤的诊断有很大的优越性。  相似文献   

12.
The results of chest radiography in 581 patients with blunt minor thoracic trauma were reviewed. Frontal and lateral views of the chest indicated pathology in 72 patients (12.4%). Pneumothorax was present in 16 patients; 4 had hemothorax. The physical examination and the results of chest radiography were not in accordance because in 6 (30%) of the 20 patients with hemo/pneumothorax the physical examination was normal. Consequently there is wide indication for chest radiography after minor blunt chest trauma.  相似文献   

13.
The purpose of the study was to evaluate the diagnostic value of pelvic radiography in the initial trauma series when compared to multidetector CT (MDCT) findings in serious blunt trauma. Inclusion criteria were blunt trauma and pelvic radiography in the initial trauma series, followed by a whole-body MDCT. A total of 1386 patients (874 male, 512 female, age 16–91 years, mean 41 years) met the inclusion criteria. Imaging studies were evaluated retrospectively by anatomical region and classified, when possible, using the Tile classification. Based on MDCT, a total of 629 injuries occurred in 226 (16%) of these 1386 patients. Radiography depicted 405 fractures in these 226 patients, giving an overall sensitivity of 55%. In 24 patients (11%) radiography was false-negatively normal. The sensitivity of radiography was mainly good in the anteroinferior parts of the pelvis, fair in the acetabulum and ileum, and poor in the posterior ring. By MDCT 141 (62%) patients were classified using the Tile classification and by radiography 133 patients (59%) were classified. MDCT and radiography showed the same type of pelvic injury in 72 patients (59%) and the subtype in 17 patients (14%). In 48 patients (40%) the pelvis was shown to be stable by radiography but unstable by MDCT. In conclusion, the sensitivity of pelvic radiography is low, and it is not reliable for determining if the pelvic injury is stable or not.  相似文献   

14.
The objective of this work was to evaluate the influence of the postprocessing tool Diamond View® (Siemens AG Medical Solutions, Germany) on image quality in conventional chest radiography. Evaluation of image quality remains a challenge in conventional radiography. Based on the European Commission quality criteria we evaluated the improvement of image quality when applying the new postprocessing tool Diamond View® (Siemens AG Medical solutions, Germany) to conventional chest radiographs. Three different readers prospectively evaluated 102 digital image pairs of chest radiographs. Statistical analysis was performed with a p value <0.05 considered as significant. Images were evaluated on basis of the modified imaging Quality Criteria by the Commission of the European Communities. Each of the 11 image quality criteria was evaluated separately using a five point classification. Statistical analysis showed an overall tendency for improved image quality for Diamond View® (DV) for all criteria. Significant differences could be found in most of the criteria. In conclusion DV improves image quality in conventional chest radiographs.  相似文献   

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Treatment goals in severe midfacial trauma are restoration of function and appearance. Restoration of function is directed at multiple organ systems, which support visual acuity, airway patency, mastication, lacrimation, smelling, tasting, hearing, and facial expression. Victims of blunt facial trauma expect to look the same after surgical treatment as before injury. Delicate soft tissues of the midface often make cosmetic reconstructive surgery technically challenging. Generally, clinical evaluation alone does not suffice to fully characterize facial fractures associated with extensive swelling, and the deeper midface is not accessible to physical examination. Properly performed computed tomography (CT) overcomes most limitations of presurgical examination. Thus, operative approaches and sequencing of surgical repair are guided by imaging information displayed by CT. Restoration of function and appearance relies on recreating normal maxillofacial skeletal anatomy, with particular attention to position of the malar eminences, mandibular condyles, vertical dimension and orbital morphology. Due to its pivotal role in surgical planning, CT scans obtained for the evaluation of severe midfacial trauma should be designed to easily depict the imaging information necessary for clinical decision making. Learning objectives: 1. Understand the facial skeletal buttress system; 2. Understand how the pattern of derangement of the buttress system determines the need for and choice of operative approach for repair of fractures in the middle third of the face; 3. Understand the role and importance of CT and CT reformations in the detection and classification of the pattern of buttress system derangement.  相似文献   

17.
Computed radiography (CR) is emerging as a digital imaging modality for use in conventional radiography. An advantage of CR over film-screen systems is the separation of image acquisition, processing and display. Selection of many different image display characteristics are possible. The system is also able to alter or enhance image details after the radiographic examination has been completed.  相似文献   

18.
Conventional radiography contributes for the majority of examinations in radiology departments. Based on the European Commission Quality Criteria we evaluated the effects on image quality when applying the new post-processing tool Diamond View (Siemens AG Medical Solutions, Germany) to conventional lumbar spine radiographs. 100 digital image pairs in two directions in two planes of lumbar spine radiographs were prospectively evaluated by two radiologists. Statistical analysis was performed with a p-value<.05 considered as significant. Images were evaluated on basis of the modified imaging Quality Criteria by the Commission of the European Communities, rated on a five-point scale. Statistical analysis showed an overall tendency for improved image quality of Diamond View (DV) for all criteria. Significant differences could be found in most of the criteria. Additional phantom analyses supported the advantage of DV. In conclusion DV improves image quality in conventional lumbar spine radiographs.  相似文献   

19.
Blackmore CC  Zelman WN  Glick ND 《Radiology》2001,220(3):581-587
PURPOSE: To determine the resource costs of the technical component of cervical spine radiography in patients with trauma and the factors that drive resource costs, to provide a model for resource cost estimation, and to compare resource costs with other methods of cost estimation. MATERIALS AND METHODS: Direct measurement was made of technologist labor and supply costs of a cohort of 409 consecutive patients with trauma who underwent cervical spine radiography. Probability of cervical spine injury was determined by reviewing emergency department medical records. An animated simulation model was used to combine cost and injury probability estimates to determine resource costs. Sensitivity analysis explored factors that determined costs and estimated uncertainty in model estimations. Comparison was made with other cost estimates. RESULTS: The average technical resource cost for cervical spine radiography was $49.60. Both direct labor ($19.60 vs $13.33; P <.005) and film ($8.39 vs $6.76; P <.005) costs were greater in patients with high probability of injury than in those with low probability of injury. Overall costs in patients with high probability of injury exceeded those in patients with low probability of injury by 33%. Resource costs exceeded Medicare resource-based relative value unit reimbursements for all patients with trauma. CONCLUSION: Resource costs of the technical components of cervical spine radiography varied with patient probability of injury and were higher than Medicare reimbursements.  相似文献   

20.
OBJECTIVE: To evaluate image quality of a large-area direct-readout flat-panel detector system in chest radiography, we conducted an observer preference study. A clinical comparative study was conducted of the flat-panel system versus the storage phosphor and standard film-screen systems. MATERIALS AND METHODS: Routine chest radiographs (posteroanterior) of 30 patients that were obtained using flat-panel, storage phosphor, and film screen systems were compared. The visibility of 10 anatomic regions and the overall image quality criteria were rated independently by three radiologists using a 5-point scale. The significance of the differences in diagnostic performance was tested with a Wilcoxon's signed rank test. Dose measurements for the three modalities were performed. RESULTS: The flat-panel radiography system showed an improved visibility in most anatomic structures when compared with a state-of-the-art conventional film-screen system and an equal visibility when compared with a storage phosphor system. The flat-panel system showed the greatest enhancement in the depiction of small detailed structures (p < 0.05) and achieved this with a reduction in overall radiation dose of more than 50%. CONCLUSION: The visibility of anatomic structures provided by this flat-panel detector system is as good as if not better than that provided by conventional or storage phosphor systems while emitting a reduced radiation dose.  相似文献   

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