[Fracture diagnosis with digital luminescence radiography]

Digital Luminescence Radiography and Conventional Radiography in Abdominal Contrast Examinations

In 326 patients abdominal contrast radiographs were compared to digital luminescence radiographs (DLR) and conventional screen-film system ones. The digital exposure dose was 50% of the conventional. In DLR, 2 different types of postprocessed images were obtained from each data set. A display with low spatial frequency enhancement filtered to look like a conventional radiograph was compared to a display with high spatial frequency enhancement. Conventional and DLR images were evaluated randomly and separately by 4 radiologists by means of a questionnaire. DLR proved to be diagnostically equivalent to the conventional technique with the exception of a slightly diminished visibility of the mucosal pattern. High spatial frequency enhancement did not provide additional diagnostic information and should be dispensed with in abdominal examinations.

Comparison of computed radiography and conventional film-screen radiography of the equine stifle

Major advantages of computed radiography are the potential reduction of dose and the possibility of postprocessing. In our study, we compared conventional radiographs to digital radiographs of the equine stifle by subjective evaluation of diagnostic quality when using a decreasing photon flux (mAs). Twelve equine stifle joints from horses of different weight and size were examined. Conventional and digital radiographs were performed identically in a caudocranial projection with the tube angled 15 degrees. A series of four radiographs was performed in each technique with an increasing photon flux starting with 2.5 mAs and going up to 5, 10, and 20 mAs. All radiographs were evaluated subjectively in a blinded fashion by seven readers in terms of contrast, bone structure, and diagnostic value and were graded using a 1-5 scale. Results from conventional and digitized radiographs were compared, and differences between the individual observers were analyzed statistically. Contrast, bone structure, and diagnostic value from digital images were rated significantly better than from conventional images (p < .001). For both techniques, a decrease in ranking was found with a decrease of photon flux. There was only slight interobserver variability. A dose reduction up to a factor of 4 compared to a 100 speed film-screen system seems to be possible without loss of information. Weight and size of the horse are not major influences.

Detection of porcine bone lesions and fissures: comparing digital selenium, digital luminescence, and analog film-screen radiography

OBJECTIVE

The purpose of our study was to compare the diagnostic performance of a digital selenium detector (Thoravision) with that of analog film-screen systems and digital luminescence radiography in skeletal radiography for the detection of fissures and lesions in porcine bones.

MATERIALS AND METHODS

One hundred bones taken from domestic pigs (50 ribs and 50 femurs) were divided into two equal groups. Fissures and bone lesions were created in 50 bones and 50 served as controls. The bones were examined using film-screen systems, digital luminescence radiography, and digital selenium radiography at various doses. Digital selenium radiography exposure values were adapted to the image geometry differing from the reference methods with a detector focus distance of 2.15 m. Four radiologists independently evaluated image quality and detectability of fissures and lesions on a five-point scale of confidence. Statistical evaluation was based on receiver operating characteristic curve analysis.

RESULTS

Fissures and bone lesions were detected most reliably using the mammography film-screen system, but the difference in the results of the analog and digital reference images did not achieve statistical significance.

CONCLUSION

Compared with analog film-screen systems, the lower spatial resolution of the digital selenium and digital luminescence radiography systems does not affect detectability of fissures and bone lesions in porcine bone. Selenium is effective in skeletal radiography for detecting fissures and bone lesions. With digital selenium and digital luminescence radiography, the surface dose can be cut to half that required for 200-speed film-screen systems without losing any diagnostically relevant information.

[Primary diagnosis of osseous carpal area injuries--a comparison of conventional examination methods with digital luminescence radiography]

Despite recent progress in improving diagnostic methods carpal bone lesions are still a major problem of primary diagnosis. Diagnostic imaging with digital luminescence radiography (DLR) allows the reliable presentation of traumatologically relevant carpal structures. In this study on 39 patients with suspected carpal bone injuries individually worked over DLR images were superior to "standard" DLR and conventional X-ray film/screen images. Though "standard" DLR images were inferior to film images edge-enhanced DLR images showed definite advantages in the demonstration of soft tissues. Fractures undetectable in conventional X-rays could not be recognized by digital imaging. In our experience bone-scanning remains the most reliable method for definite exclusion of carpal bone fractures after standard and digital X-ray methods are exhausted.