Evaluation of the microstructure, chemical composition, and image quality of different PSP receptors

Abstract

This study aimed to assess the microstructure, chemical composition, and image quality of different photostimulable phosphor plates (PSP). Four PSP systems, Express ® , Digora ® , VistaScan ® , and Apixia, ® were assessed. Five radiographs of a homogeneous acrylic phantom were obtained with the PSP of each system, to acquire a total of 20 images. The images were objectively evaluated for uniformity using mean grey and standard deviation (SD) of their grey values. PSP receptors were analyzed using scanning electron microscopy (SEM) to determine the thickness of the granule layer and the size of the granules. The chemical composition of the PSP receptors was analyzed using total reflection X-ray fluorescence (TXRF). VistaScan showed more uniform and higher density images than the other tested systems (p < 0.05), as well as the lowest SD of grey values (p < 0.05).Regarding the microstructure of the receptors, Digora and VistaScan had thicker granule layers than Express and Apixia, and VistaScan had smaller granules than Digora and Express (p < 0.05). Fourteen chemical elements were detected in the receptors, with barium being the element with the highest concentration in all PSP systems. The microstructure, chemical composition, and image quality varied among all four PSP receptors studied. VistaScan receptors showed the smallest variation in granule size, one of the thickest granule layers, and the most uniform and least noisy images.

Could the radiographic image quality be affected by the excessive use of the photostimulable phosphor plate?

“…A decrease in the mean of gray values calculated on a center ROI covering a wide area of the PSP represents an increase in the radiographic density 11 , 12 . Regarding the contrast variation, these values varied among the acquisitions groups without a pattern of increase or decrease.…”

“…Based on its location, another four ROIs of the same size were symmetrically distributed in the upper and lower corners of the radiograph ( Figure 1 -B). Subsequently, to analyze the overall noise of the image, the average of the standard deviation (SD) of gray values obtained for all ROIs was calculated 11 , 12 . Finally, the macro function available in the software was employed to standardize the position of the ROIs for all images evaluated.…”