Acute traumatic aortic injury (ATAI) is a life-threatening injury. CT is the imaging tool of choice, and the knowledge of direct and indirect signs of injury, grading system, and current management ...protocol helps the emergency radiologist to better identify and classify the injury and provide additional details that can impact management options. Newer dual-source CT technology with ultrafast acquisition speed has also influenced the appropriate protocol for imaging in patients with suspected ATAI. This review highlights the imaging protocol in patients with blunt trauma, CT appearance and grading systems of ATAI, management options, and the role of the multidisciplinary team in the management of these patients. We also briefly review the current literature on the definition, treatment, and follow-up protocol in patients with minimal aortic injury.
Two decades have passed since the publication of laboratory studies of satisfaction of search (SOS) in chest radiography. Those studies were performed using film. The current investigation tests for ...SOS effects in computed radiography of the chest.
Sixty-four chest computed radiographs half demonstrating various "test" abnormalities were read twice by 20 radiologists, once with and once without the addition of a simulated pulmonary nodule. Receiver-operating characteristic detection accuracy and decision thresholds were analyzed to study the effects of adding the nodule on detecting the test abnormalities. Results of previous studies were reanalyzed using similar modern techniques.
In the present study, adding nodules did not influence detection accuracy for the other abnormalities (P = .93), but did induce a reluctance to report them (P < .001). Adding nodules did not affect inspection time (P = .58) so the reluctance to report was not associated with reduced search. Reanalysis revealed a similar decision threshold shift that had not been recognized in the early studies of SOS in chest radiography (P < .01) in addition to reduced detection accuracy (P < .01).
The nature of SOS in chest radiography has changed, but it is not clear why.
SOS may be changing as a function of changes in radiology education and practice.
Although a checklist has been recommended for preventing satisfaction of search (SOS) errors, a previous research study did not demonstrate that benefit. However, observers in that study had to turn ...away from the image display to use the checklist. The current study tested a vocalized checklist to avoid this constraint.
A total of 64 chest computed radiographs, half containing various "test" abnormalities, were read twice by 20 radiologists, once with and once without the addition of a simulated pulmonary nodule. Readers used a vocalized checklist-directing search. Receiver operating characteristic (ROC) detection accuracy and decision thresholds were analyzed to study the effects of adding the nodule on detecting the test abnormalities.
Adding nodules induced a substantial reluctance to report the other abnormalities (P < 0.001), as had been the case in the most recent study of the SOS effect in radiography.
The vocalized checklist did not reduce nor eliminate the SOS effect on readiness to report further abnormalities. Although useful for organizing search and reporting, particularly among students, a vocalized checklist does not prevent SOS effects.
We tested whether satisfaction of search (SOS) effects that occur in computed tomography (CT) examination of the chest on detection of native abnormalities are produced by the addition of simulated ...pulmonary nodules.
Two experiments were conducted. In the first experiment, 70 CT examinations, half that demonstrated diverse, subtle abnormalities and half that demonstrated no native lesions, were read by 18 radiology residents and fellows under two experimental conditions: presented with and without pulmonary nodules. In a second experiment, many of the examinations were replaced to include more salient native abnormalities. This set was read by 14 additional radiology residents and fellows. In both experiments, detection of the natural abnormalities was studied. Receiver operating characteristic (ROC) curve areas for each reader-treatment combination were estimated using empirical and proper ROC models. Additional analyses focused on decision thresholds and visual search time on abnormality-free CT slice ranges. Institutional review board approval and informed consent from 32 participants were obtained.
Observers more often missed diverse native abnormalities when pulmonary nodules were added, but also made fewer false-positive responses. There was no change in ROC area, but decision criteria grew more conservative. The SOS effect on decision thresholds was accompanied by a reduction in search time on abnormality-free CT slice ranges.
The SOS effect in CT examination of the chest is similar to that found in contrast examination of the abdomen, involving induced visual neglect.
The purpose of this study was to determine whether there are identifiable factors that dissuade female medical students from entering the field of radiology.
An anonymous survey was completed by ...medical students at the end of their third- or fourth-year radiology clinical clerkships at five institutions. In addition to demographic data and residency choice, respondents ranked 10 factors in order of importance to their choice of career. For respondents who did not consider radiology a possible career, a second set of eight factors was ranked for importance in dissuading them.
Two hundred eighty-eight respondents completed the survey, 152 (53%) men and 136 (47%) women. Both men and women reported direct patient contact and intellectual stimulation as the most important factors in deciding on a specialty. For those who chose radiology, intellectual stimulation and use of emerging technology were significantly (p < 0.05) more important than other factors. The factor that most strongly (96%) dissuaded men and women from a career in radiology was lack of direct patient contact. There was no significant difference between men and women in ranking factors that dissuaded them from applying to radiology residencies; however, nearly one third of the female respondents cited competitiveness of the residency process as important.
Patient contact remains an important factor for medical students choosing a career. To attract high-caliber students, medical schools should expose students to areas of radiology involving patient interaction. Academically qualified women should be identified early during their careers and encouraged to apply for radiology residencies.
Integral to the mission of the National Institutes of Health-sponsored Lung Imaging Database Consortium is the accurate definition of the spatial location of pulmonary nodules. Because the majority ...of small lung nodules are not resected, a reference standard from histopathology is generally unavailable. Thus assessing the source of variability in defining the spatial location of lung nodules by expert radiologists using different software tools as an alternative form of truth is necessary.
The relative differences in performance of six radiologists each applying three annotation methods to the task of defining the spatial extent of 23 different lung nodules were evaluated. The variability of radiologists' spatial definitions for a nodule was measured using both volumes and probability maps (p-map). Results were analyzed using a linear mixed-effects model that included nested random effects.
Across the combination of all nodules, volume and p-map model parameters were found to be significant at P < .05 for all methods, all radiologists, and all second-order interactions except one. The radiologist and methods variables accounted for 15% and 3.5% of the total p-map variance, respectively, and 40.4% and 31.1% of the total volume variance, respectively.
Radiologists represent the major source of variance as compared with drawing tools independent of drawing metric used. Although the random noise component is larger for the p-map analysis than for volume estimation, the p-map analysis appears to have more power to detect differences in radiologist-method combinations. The standard deviation of the volume measurement task appears to be proportional to nodule volume.
Image perception studies have been difficult to perform using clinical images because of the problems associated with obtaining proven abnormalities and appropriate normal controls. The objective of ...this research was to develop and evaluate interactive software that allows the seamless removal, archiving and insertion of abnormal areas from computed tomography (CT) lung image sets for use in image perception research.
The software tools for removing, archiving, and adding lesions are described in detail. The efficacy of the software to remove abnormal areas of lung CT studies was evaluated by having radiologists select the one altered image from a display of four. The software for adding lesions was evaluated by having radiologists classify displayed CT slices with lesions as real or artificial along with their confidence level.
Observers could not reliably detect when images had been altered by the software. In the lesion-removal experiment, the observers correctly identified the altered display in only 15.8 +/- 2.8 of 56 sets. In the lesion-add experiment, the observers correctly identified the artificially placed lesions in 38.2 +/- 3.9 of 77 sets. The frequency distribution of the correct responses did not differ from that expected from chance selection.
The results from both of these experiments demonstrate that radiologists could not distinguish between original and altered images. We conclude that this software can be used with volumetric CT lung images for creating normal control and target data sets for medical image perception research.
Background. To determine the relative utility of positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging with Combidex (MRI-C) in the non-invasive staging of ...non-small cell lung cancer (NSCLC) mediastinal lymph nodes (MLN), we compared the three tests’ individual performance with surgical mediastinal sampling. In contrast to prior studies, cytology was not used.
Methods. The MLN were evaluated using PET and CT in 64 NSCLC patients. MRI-C was performed in 9 of these patients. MLN with a PET standard uptake value greater than or equal to 2.5, or greater than 1 cm in the short axis by CT or lack of MRI-C signal change were considered positive for metastatic disease. All MLN were sampled and subjected to standard pathologic analysis. PET, CT, and MRI-C scans were interpreted blinded to the histopathological results. Sensitivity, specificity, and accuracy for each scan type to appropriately stage MLN was determined using pathologic results as the standard.
Results. Thirty patients had stage I disease, 8 stage II, 9 stage IIIA, 7 stage IIIB, and 10 stage IV. Two-hundred-and-thirty MLN were sampled. Sixteen patients had metastatic mediastinal disease. Compared to the pathological results, PET, CT, and MRI-C had a sensitivity, specificity, and accuracy of 70%, 86%, 84%; 65%, 79%, 76%; 86%, 82%, and 83%, respectively. PET and MRI-C were statistically more accurate than CT (
p < 0.001). In cases where PET and CT did not identify MLN involvement with NSCLC, 8% (2/25) were pathologically positive.
Conclusions. PET and MRI-C are statistically more accurate than CT. However, the differences are small and may not be clinically relevant. No technique was sensitive or specific enough to change the current recommendation to perform mediastinoscopy for MLN staging in NSCLC.
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