Intracranial aneurysm as an incidental finding.

This report presents an incidental finding of a potentially life-threatening large fusiform aneurysm of the internal carotid artery at the level of the posterior communicating artery in a patient who reported with complaints relating to the presence of a radiolucent lesion in the mandible that was diagnosed as odontogenic keratocyst. This case highlights the need to study a case in detail in preparation for prescribing the appropriate advanced imaging modality examination, and also to carefully evaluate the entire imaged volume for incidental pathology and not just the region of interest. This report assumes significance in the light of widespread use of cone beam CT by dental clinicians for routine diagnostic tasks without a formal interpretation being carried out on all such studies.

Comparison of a photostimulable phosphor system with film for dental radiology.

This study compared the imaging performance of a photostimulable phosphor system with E speed film for dental radiography. The response of each imaging system was measured as a function of radiation exposure. Measurements were also made of imaging performance in terms of the limiting spatial resolution and low contrast detectability. Photostimulable phosphors had a wider dynamic range in comparison with film. The limiting spatial resolution of the photostimulable phosphor was approximately 6.5 lp/mm and independent of image magnification. For film, the limiting spatial resolution was in the range 11 to 20 lp/mm depending on image magnification. At the same radiation exposure, low contrast detectability of the photostimulable phosphor was superior to that of film. Major benefits of photostimulable phosphor systems include the elimination of chemical processing and an improved low contrast detectability performance.

Centralized automated quality assurance for large scale health care systems. A pilot method for some aspects of dental radiography.

President Clinton's Health Security Act proposes the formation of large scale health plans with improved quality assurance. Dental radiography consumes 4% ($1.2 billion in 1990) of total dental expenditure yet regular systematic office quality assurance is not performed. A pilot automated method is described for assessing density of exposed film and fogging of unexposed processed film. A workstation and camera were used to input intraoral radiographs. Test images were produced from a phantom jaw with increasing exposure times. Two radiologists subjectively classified the images as too light, acceptable, or too dark. A computer program automatically classified global grey level histograms from the test images as too light, acceptable, or too dark. The program correctly classified 95% of 88 clinical films. Optical density of unexposed film in the range 0.15 to 0.52 measured by computer was reliable to better than 0.01. Further work is needed to see if comprehensive centralized automated radiographic quality assurance systems with feedback to dentists are feasible, are able to improve quality, and are significantly cheaper than conventional clerical methods.

An imaging standard for dentistry. Extension of the radiology DICOM standard.

No standard exists for electronic communication of dental images. However, maxillofacial radiology, being part of general radiology, does have the advantage of having an applicable standard: The American College of Radiology-National Electrical Manufacturers Association Standard for Digital Imaging and Communications in Medicine (Version 3.0). This standard encourages open systems interconnection of imaging equipment over standard networks while maintaining compatibility with earlier point-to-point connection standards. This standard, to be voted on in 1993, moves the American College of Radiology-National Electrical Manufacturers Association into full conformance with the International Standards Organization reference model for network communications. An object-oriented information model lays the groundwork for harmonization with other medical communications standards. This article outlines the American College of Radiology-National Electrical Manufacturers Association components and discusses the rationale of object-oriented design. The relevance of the standard to dentistry is discussed.

Assessment of the DMF-S index with the use of bitewing radiographs.

A study population of students (ages 14 to 18 years) was examined radiographically (bitewings) and by clinical DMF-S evaluations. Results revealed a clinically detected total DMF-S of 8.31 with a D-S of 4.86. Decay clinically detected on premolars and molars alone was 4.38, whereas an additional 4.88 surfaces were radiographically detected as being carious. It was determined that a multiplying factor of 1.59 should be used in the present study population to better assess the actual total DMF-S figure. Validity of the correction factor was tested and validated.

A follow-up study of a third-party radiographic evaluation system.

A follow-up study was conducted to evaluate the performance of the rating system for third-party carriers which was developed and instituted in 1976. Further, the technical quality of radiographs submitted under the system was evaluated. The conditions and parameters of the second study were identical to those of the original work. Statistical comparison of the data from both studies shows a significant decrease in the frequency of error occurrences over the 3-year span between the studies.

A bitewing radiographic study of a population of diabetic and nondiabetic rhesus monkeys.

A population of 7 diabetic and 13 nondiabetic rhesus monkeys (Macacca mulatta) were examined radiographically using bitewing imaging techniques. Each subject was scored radiographically for bone levels, periodontal ligament (PDL) widening, radiographic calculus, and carious lesions. Prior to examinations blood samples were obtained for fasting blood glucose levels. Results indicated that all clinical variables were generally greater for the diabetic group, with bone loss being the only statistically significant parameter. Calculus levels, however, were found to be greater radiographically in the nondiabetic group. In viewing the study population as a single group of 20 monkeys, decreased bone levels were found to be positively correlated with PDL widening and blood glucose levels suggesting an association of hyperglycemic states with possible decreased resistance to infection. It was concluded that carbohydrate intolerance with hyperglycemia in diabetes mellitus may be associated with the radiographic variable of increased bone resorption using an objective system of measurement for evaluation and scoring. Without a quantitative system of measurement such as devised in this study, other radiographic variables such as PDL widening, calculus deposits, and carious lesions may not be accurately tested against one another or correlated with other experimental clinical parameters.