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Biomedical subjects

J B Ludlow

Publications and source records attributed to J B Ludlow.

62 records · Page 4Linked to original sources
PubMed1988

Vertical tomography of the temporomandibular joint with the use of a dental chair and intraoral x-ray unit.

While designs for tomographic imaging are numerous, there are no reports in the literature of a vertical tomographic device based on a principle of patient movement relative to a fixed x-ray source. A vertical tomographic device was constructed with the use of a conventional dental chair to generate tomographic movement and a variable kilovolt (peak) intraoral x-ray unit as the x-ray generator. The device was assembled with commonly available components and construction elements machined from standard metal stock. Images made with 5 x 7 inch cassettes with RP X-Omat film and regular intensifying screens were compared with similar images produced by a commercial linear tomographic device costing about five times as much. Comparison of images of the temporomandibular joint of a tissue-equivalent skull phantom produced by transcranial technique and prototype and control tomograms demonstrated superior imaging produced with tomographic techniques and similar image quality between prototype and control-generated films.

Dental Equipment↗
PubMed1988

Use of a "sandwich" technique to control image geometry in clinical studies comparing intraoral xeroradiographs and E-speed films.

A method of superimposing a film on a xeroradiographic (XR) cassette for simultaneous intraoral exposure is evaluated for use as an imaging technique in clinical studies comparing Ektaspeed film and XR images. Sandwich images were indistinguishable from those produced by conventional technique. Pilot studies were conducted with 104 patients who had symptomatic dental problems. No significant differences were found in diagnostic usefulness or image quality between XR and film radiographs when sign test analysis was used. The sandwich technique yielded film and XR images with duplicate image geometry while reducing patient exposures to one half of that used in conventional image comparison protocols.

Evaluation Studies as Topic↗
PubMed1987

Diagnostic imaging assessment of experimental intraoral "folded film".

"Folded film" is an experimental technique of film preparation that provides diagnostic imaging of intraoral structures with one-half the radiation required to produce conventional images. In this study, folded film periapical images were compared with similar conventional D- and E-speed film images with the use of 12 criteria for diagnostic visualization. Nineteen examiners judged folded films to be slightly less diagnostic than D-speed film images and somewhat more diagnostic than E-speed films. All systems were judged adequate for diagnostic visualization of bone and teeth.

Radiographic Image Enhancement↗
PubMedDate not supplied

Diagnostic accuracy of intraoral film and direct digital images for detection of simulated recurrent decay.

UNLABELLED: This study compared the diagnostic accuracy of bitewing images for detection of simulated recurrent caries using the following imaging modalities: Ektaspeed Plus film and different digital imaging system technologies comprised of a charge-coupled device (CCD) based digital imaging unit, a photo-stimulable phosphor (PSP) based unit and contrast- and brightness-enhanced PSP images. STUDY DESIGN: Twenty-four extracted posterior teeth with MOD inlay preparations were secured in models simulating a natural arrangement of teeth. Lesions were created in proximal boxes using dental burs of varying sizes. Defects were filled with wax and plaster and preparations were restored with composite or amalgam. RESULTS: Averages of receiver operating curve areas (Az) revealed diagnostic performances of Az = 0.74 for film, Az = 0.80 for CCD, Az = 0.73 for unenhanced PSP and Az = 0.64 for enhanced PSP. The differences between these means were significant (MANOVA p < 0.0001). Unenhanced PSP produced significantly poorer performance than other modalities. CCD performance was not significantly better than enhanced PSP. Lesions under radiopaque composite restorations were easier to detect, followed by those under amalgam and radiolucent composites across imaging modalities and lesion locations. Based on lesion location, those located at the buccal point angle were easiest to detect, followed by those at mid-gingival floor and lingual-point angle sites. CONCLUSIONS: Contrast and brightness-enhanced digital images enabled better signal detection and a comparable performance with film for detection of artificially induced recurrent caries.

Analysis of Variance↗