Perception of anatomical structures in digitally filtered and conventional panoramic radiographs: a clinical evaluation

Abstract

Objectives: The aims of the study were to compare subjective image quality of clinical images obtained with a storage phosphor plate (SPP)-based digital and conventional filmbased panoramic system for the visualization of various anatomical structures and to evaluate the effect of various processing algorithms on image interpretation. Methods: Panoramic radiographs were taken in 42 patients both with film and with a SPP system. SPP images were treated with shadow, sharpen, negative, greyscale sigma and greyscale exponential filters. Four observers subjectively evaluated films and unfiltered and filtered SPP images for the visibility of anatomical structures with various radiodensities as well as for overall image quality on a three-point rating scale. The statistical methods used were Kruskal-Wallis, odds ratio analysis and Cohen's kappa. Results: No statistically significant difference was found between film and unfiltered digital images except for low-contrast structures (P . 0.05). Film images were preferred for the visibility of low-contrast structures (P , 0.05). Best overall image quality was obtained with sharpened images (P , 0.05) followed by films and unfiltered digital images. Among all filtered images, sharpened ones received the highest ratings for the visibility of all anatomical structures (P , 0.05). The intra-and interobserver agreement ranged between moderate and substantial and between fair and moderate, respectively. Conclusions: Film and unfiltered SPP-based panoramic images performed equally well in terms of overall quality; however, films were best for the perception of low-contrast structures. The sharpening filter may be recommended for enhancing SPP panoramic images to improve the visual perception of most of the anatomical structures as well as overall quality.

Influence of cone beam CT enhancement filters on diagnosis ability of longitudinal root fractures

“…13 One possible explanation for these contradictions may be that the effectiveness of the filters varies depending on the type of filter being used. 11,15 Instead of contributing to the visualization of fractures, certain enhancement filters have masked the ability to visualize by increasing the digital image noise, whereas others have not improved the diagnosis. 22 A recent study comparing high-resolution and standard zoom imaging modes in CBCT for the detection of longitudinal root fracture showed no significant differences among the diagnostic values of the two image modes used in the diagnosis of root fracture or in the presence of root canal restorations.…”

“…[9][10][11][12][13] Other studies have evaluated the effect of different digital image filters on various relevant anatomical structures. 14,15 Some other studies have evaluated effects of sharpen filters on CBCT images to detect transverse root fractures and external root resorption. 16,17 However up to now, there is a lack of studies on the influence of these enhancement filters on diagnosis ability of longitudinal root fractures.…”

Evaluation of oral mucosal diseases: inter‐ and intra‐observer analyses

“…Inter‐ and intra‐observer differences are important when visual parameters play a crucial diagnostic role. This issue has been studied in other fields of medicine and dentistry involving subjective visual diagnoses such as dermatology (13) and oral radiology (14). Subjective histopathologic evaluation of oral biopsies by oral pathologists has been studied with repeated findings of inter‐ and intra‐observer differences (15).…”

The ‘Sharpen’ filter improves the radiographic detection of vertical root fractures

“…Az values for the original and filtered imagesNascimento et al Diagnosis of root fractures using digital filters International Endodontic Journal, 48, 428-434, 2015 appearance of depth based on the relative densities of the original image, enhancing the borderlines of the structures(Baksi et al 2010). Both 3D Emboss and Shadow can be used to visualize paths of structures that pass through dark and light regions of an image, such as endodontic files for length measurement, or root fractures and similar pathology.…”