Stability of a dry laser imaging system.

Laser imagers are the method of choice for creating hard copies of electronic images, such as computed tomograms and computed radiographs. New dry laser imagers use heat processing rather than wet chemical processing. This article describes tests assessing the stability and reproducibility of dry-processed laser images under normal conditions. The authors conclude that dry laser images compare favorably with wet laser images, although testing under extreme conditions is needed.

Entrance skin exposure in PA chest radiography.

To determine whether entrance skin exposure during chest radiography is related to the thickness of the patient's chest, the authors used a dose-area product meter to record ESE during posteroanterior chest examinations of adult male patients. Manual adjustment of collimation and automatic exposure control were used. Analysis of the results showed a weak correlation between radiation exposure and chest thickness. The equivalent chest thicknesses of anthropomorphic phantoms are thinner than the chest thicknesses of most adult patients. Therefore, if it is necessary to measure the entrance skin exposure to a patient, it should be measured directly or computed from the actual technique used. An examination of the distribution of recorded dose-area product shows that this parameter can be a quality control criterion for limiting the field size in manual collimation.

Measurement of skin entrance exposure with a dose-area-product meter at chest radiography.

Skin entrance exposure measurements obtained with a dose-area-product meter and thermoluminescent dosimeters were compared at posteroanterior and lateral chest radiography in 52 adult male patients. In a linear regression analysis of data collected in both views, values of 1.23 +/- 0.02 and 1.26 +/- 0.01 (r = .98 and .99) were found for the ratios of thermoluminescent-dosimeter and dose-are-product exposures, respectively. Skin entrance exposures from 16 mR (4.13 microC/kg) to 150 mR (38.7 microC/kg) in the posteroanterior view and 24 mR (6.19 microC/kg) to 475 mR (123 microC/kg) in the lateral view were found. Dose-area-product meters offer a rapid and accurate means to measure skin entrance exposure when the radiography field size is known.

The role of radiology in the Oklahoma City bombing.

PURPOSE: To evaluate the role of radiologic services in the assessment of injuries and identification of deceased victims of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Okla. MATERIALS AND METHODS: In cooperation with the Oklahoma University Health Sciences Center Disaster Studies Group, all victims of the Oklahoma City bombing who were treated in hospitals were evaluated. All radiologic studies performed in these patients during a 4-week period after the bombing were recorded. Major injuries incurred by the victims were noted but were not documented. In addition, assistance provided by radiologic services to the medical examiner's office for identification of deceased victims was assessed. RESULTS: On the day of the bombing, 99% (480 of 485) of the imaging studies performed were either plain radiography, primarily of the extremities and chest, or computed tomography (CT), half of which were of the head. Six deceased victims were identified solely by means of characteristics on radiographs. CONCLUSION: Almost all bombing-related radiologic studies were either plain radiography or CT. Other modalities had only limited roles. In deceased victims, plain radiography aided identification, and in many other victims it allowed localization of materials that were potential pieces of evidence.

Tympanic membrane temperature during experimental otitis media due to Streptococcus pneumoniae in chinchillas.

The relationship between tympanic membrane temperature and acute purulent otitis media was investigated using thermistor probes to measure surface temperature of the tympanic membrane in chinchillas with experimental unilateral otitis media due to Streptococcus pneumoniae. Sedated animals were kept on a thermally insulated surface during the procedure to avoid hypothermia. Although the animals' core temperature rose during middle ear infection, direct measurement of tympanic membrane temperature did not show a significant difference between the infected and uninfected contralateral ears.