Evaluation of low-cost computer monitors for the detection of cervical spine injuries in the emergency room: an observer confidence-based study

Health, social, and economic consequences of neck injuries: a controlled national study evaluating societal effects on patients and their partners

STUDY DESIGN

National register-based matched case-control study.

OBJECTIVE

The aim of this study was to estimate the direct and indirect costs of neck injuries, except fractures, in a national sample of patients and their spouses.

SUMMARY OF BACKGROUND DATA

Despite neck injuries causing significant socioeconomic burdens, there is insufficient information about the time course, as well as the effect on their spouses.

METHODS

Using records from the Danish National Patient Registry 1998-2009, all patients with a diagnosis of neck injury and their spouses were identified and compared with randomly chosen controls matched for age, sex, geographical area, and civil status. Direct costs included frequency of primary and hospital sector contacts and procedures and medication. Indirect costs included the effect on labor supply. Social transfer payments were included to illustrate the effect on national accounts. All cost data were extracted from national databases.

RESULTS

The register contributed 94,224 patients, and 372,341 matched controls were identified. The percentages of married or cohabiting individuals were approximately 47.5% in both groups. Patients with neck injury had significantly higher rates of health-related contacts, medication use, and higher socioeconomic costs than controls. To a lesser extent, they also had lower employment rates, and those employed generally had lower incomes. Furthermore, the patients had already presented negative social- and health-related status up to 11 years before the first diagnosis, which became more pronounced for those with the highest costs. The health effects on costs were present regardless of age group and sex, and it was also seen for the patients' spouses.

CONCLUSION

Neck injuries are associated with major socioeconomic consequences for patients, their spouses, and the society. However, the increased expenses during subsequent years cannot be explained by the injury alone, because these patients already had elevated expenses prior to the injury. This indicates some selection of increased vulnerability for both patients and their spouses.

Comparison of the commercial color LCD and the medical monochrome LCD using randomized object test patterns

Workstations and electronic display devices in a picture archiving and communication system (PACS) provide a convenient and efficient platform for medical diagnosis. The performance of display devices has to be verified to ensure that image quality is not degraded. In this study, we designed a set of randomized object test patterns (ROTPs) consisting of randomly located spheres with various image characteristics to evaluate the performance of a 2.5 mega-pixel (MP) commercial color LCD and a 3 MP diagnostic monochrome LCD in several aspects, including the contrast, resolution, point spread effect, and noise. The ROTPs were then merged into 120 abdominal CT images. Five radiologists were invited to review the CT images, and receiver operating characteristic (ROC) analysis was carried out using a five-point rating scale. In the high background patterns of ROTPs, the sensitivity performance was comparable between both monitors in terms of contrast and resolution, whereas, in the low background patterns, the performance of the commercial color LCD was significantly poorer than that of the diagnostic monochrome LCD in all aspects. The average area under the ROC curve (AUC) for reviewing abdominal CT images was 0.717±0.0200 and 0.740±0.0195 for the color monitor and the diagnostic monitor, respectively. The observation time (OT) was 145±27.6 min and 127±19.3 min, respectively. No significant differences appeared in AUC (p = 0.265) and OT (p = 0.07). The overall results indicate that ROTPs can be implemented as a quality control tool to evaluate the intrinsic characteristics of display devices. Although there is still a gap in technology between different types of LCDs, commercial color LCDs could replace diagnostic monochrome LCDs as a platform for reviewing abdominal CT images after monitor calibration.

Contrast sensitivity of digital imaging display systems: contrast threshold dependency on object type and implications for monitor quality assurance and quality control in PACS

The American Association of Physicists in Medicine Task Group 18 has published standards and quality control (QC) guidelines to ensure consistency and optimal quality for digital image display systems (DIDSs). In many of these recommended QC tests, static test patterns that contain low-contrast objects are often used to assess and validate the quality of a DIDS. These low-contrast objects often have the shape of circular disks or squares with sharp edges, neither of which resemble most of the diagnostic findings in medical images. On the other hand, circular objects with fuzzy boundaries bear a closer resemblance to lung nodules in chest radiography and masses in mammography; thus, they may be more clinically relevant in assessing display system quality. In this article human observers' contrast sensitivities of circular objects with sharp edges and those with fuzzy ones were investigated. The contrast thresholds of human viewers using a consumer-grade color LCD monitor and a medical-grade monochrome LCD monitor were measured for objects of various sizes displayed against uniform backgrounds with various luminance levels. Contrast-detail curves for circular objects with sharp edges and those with fuzzy boundaries were measured and compared. It was found that contrast thresholds for objects with fuzzy boundaries were higher (i.e., the objects were more difficult to detect) than those with sharp edges. Objects with fuzzy boundaries were potentially more sensitive in distinguishing quality differences among image display devices and thus may be a better QC measurement in detecting subtle deterioration in image display devices.