Thomas R Kleinfelder, BS, graduated with a bachelor of science degree in medical radiation science from Curtin University in Perth, Australia. He currently works for Royal Perth Hospital.
Curtise KC Ng, PhD, SFHEA, is a senior lecturer for the department of Medical Radiation Science at Curtin University in Perth, Australia.
Radiol Technol. 2022 Jul-Aug;93(6):544-554.
To investigate the effects of image postprocessing functions (ie, edge enhancement, noise reduction, and sharpening) that are available on digital radiography systems, including computed radiography (CR) and direct digital radiography (DDR), for detection of wooden, soft tissue foreign bodies.
Dorsoplantar and lateral porcine foot radiographs with 4 lengths of wooden foreign bodies (no foreign bodies, 2 mm, 5 mm, and 10 mm) placed 1 mm (superficial) and 1 cm (deep) below the skin were acquired by CR and DDR systems using 10 exposure factors. Images were postprocessed to produce 960 images, including original CR, original DDR, sharpened CR, sharpened DDR, edge-enhanced DDR, and noised-reduced DDR images. Contrast-to-noise ratios (CNR) were used for objective assessments of foreign body visibility on the images. Six Australian radiologic technologists were recruited to review selected images. Australia allows radiologic technologists to provide initial comments on plain radiographs with the supervision of a radiologist. Technologists rated the visibility of foreign bodies using a 4-point scale to determine diagnostic performances of different image receptor and postprocessing types. Means, standard deviations, analyses of variance, and intraclass correlation coefficients were calculated for statistical analyses.
Among the CR and DDR images with and without postprocessing, the edge-enhanced DDR images had the highest overall mean CNR value (3.39, = .003) and sensitivity (35.13%). The sensitivity of the edge-enhanced DDR images for detecting the 10 mm foreign body was 43.33%.
Edge-enhanced DDR can be considered an additional tool for suspected wooden, soft tissue foreign body diagnoses in rural areas where digital radiography is the only available imaging modality. This would allow some patients in rural areas to avoid long-distance travel to access sonography or computed tomography to detect foreign bodies, which could minimize emotional, financial, and social costs.
This study shows that the image postprocessing function of the DDR system can detect wooden, soft tissue foreign bodies. Edge enhancement, specifically, can improve wooden, soft tissue foreign body detection, especially for large foreign bodies (≥ 10 mm).
研究数字射线摄影系统（包括计算机射线摄影（CR）和直接数字射线摄影（DDR））上可用的图像后处理功能（例如边缘增强、降噪和锐化）对检测木质、软组织异物的影响。
使用 10 种曝光因子，通过 CR 和 DDR 系统获取 4 个长度的木质异物（无异物、2mm、5mm 和 10mm）的背跖位和侧位猪足 X 光片，异物分别放置在皮肤下 1mm（表浅）和 1cm（深部）处。对图像进行后处理，生成 960 张图像，包括原始 CR、原始 DDR、锐化 CR、锐化 DDR、边缘增强 DDR 和降噪 DDR 图像。对比噪声比（CNR）用于客观评估图像上异物的可见度。招募了 6 名澳大利亚放射技师来审查选定的图像。澳大利亚允许放射技师在放射科医生的监督下对普通 X 光片进行初步评论。技师使用 4 分制对异物的可见度进行评分，以确定不同图像接收器和后处理类型的诊断性能。计算平均值、标准差、方差分析和组内相关系数进行统计分析。
在有和没有后处理的 CR 和 DDR 图像中，边缘增强的 DDR 图像具有最高的总体平均 CNR 值（3.39， =.003）和灵敏度（35.13%）。边缘增强的 DDR 图像检测 10mm 异物的灵敏度为 43.33%。
边缘增强的 DDR 可被视为在数字射线摄影是唯一可用成像方式的农村地区怀疑存在木质、软组织异物时的一种额外工具。这将使农村地区的一些患者避免长途旅行去接受超声或计算机断层扫描来检测异物，从而最大限度地减少情感、经济和社会成本。
本研究表明，DDR 系统的图像后处理功能可以检测木质、软组织异物。具体来说，边缘增强可以提高木质、软组织异物的检测，特别是对于较大的异物（≥10mm）。
