University Hospital Southwest Denmark, Department of Radiology and Nuclear Medicine, Finsensgade 35, 6700 Esbjerg, Denmark.
Radiography (Lond). 2021 May;27(2):453-458. doi: 10.1016/j.radi.2020.10.012. Epub 2020 Nov 4.
Vendors offer intensive care beds with integrated detector trays for bedside radiography, promoting better ergonomics and patient comfort. However, no documentation of the effects on diagnostic image quality has been located. This study examines measured and subjective image quality of supine bedside chest radiographs with and without use of such a detector tray.
A contrast-detail phantom (CDRAD 2.0) was exposed using standard supine chest exposure parameters. Plexiglass plates of 16 and 21 cm were placed in front to simulate patient attenuation for standard and adipose patients. Exposures were repeated with the detector placed in tray and directly in bed. Images were analysed using dedicated software giving a figure-of-merit IQFinv. Results were compared using ANOVA. Then an anthropomorphic chest phantom (Lungman) was exposed using the same parameters, and the same placements of the detector. Exposures were done with and without extra conformal tissue to simulate varying patient sizes, and with and without added typical intensive care equipment. Images were analysed by two radiologists using a three-point scale, on five image quality criteria. Radiologist also stated whether the images were sufficient for diagnosis. Results were compared using Visual Grading Characteristics, using dedicated software, resulting in Areas Under the Curve (AUC-VGC) for each combination and criteria. Inter- and intra-rater reliability were assessed with kappa statistics. Composite Visual Grading Analysis (VGAS) scores were calculated for each image. Both IQFinv and were normalized and compared.
For all criteria both IQFinv and AUC-VGC was significantly better when exposing the detector directly in bed, than with the detector placed in the tray across all exposures. When stratified into thin and adipose patients, IQFinv decreased significantly for thin patients, while VGAS-scores did not. For adipose patients, both figures were significantly lower with the detector in the tray.
Use of detector tray for bedside chest imaging decreases image quality.
Radiographers should critically evaluate image quality and experimentally determine optimal exposure factors, when taking equipment with integrated trays into use.
供应商提供了带有集成探测器托盘的重症监护病床，用于床边放射摄影，以提高更好的人体工程学和患者舒适度。然而，尚未找到有关诊断图像质量影响的文件。本研究检查了使用和不使用这种探测器托盘的仰卧位床边胸部 X 光片的测量和主观图像质量。
使用标准仰卧位胸部曝光参数对对比度细节幻影（CDRAD 2.0）进行曝光。在前面放置有机玻璃板 16 和 21 厘米，模拟标准和肥胖患者的患者衰减。将探测器放置在托盘和直接在床上重复曝光。使用专用软件分析图像，给出度量标准 IQFinv。使用方差分析比较结果。然后使用相同的参数和探测器的相同放置位置对人体胸部幻影（Lungman）进行曝光。使用额外的贴合组织模拟不同的患者体型进行曝光，并使用和不使用添加典型的重症监护设备进行曝光。使用三位评分法，对五个图像质量标准，由两位放射科医生对图像进行分析。放射科医生还表示图像是否足以进行诊断。使用专用软件的视觉分级特征（VGC）比较结果，为每个组合和标准生成曲线下面积（AUC-VGC）。评估了组内和组间的可靠性，并使用kappa 统计量。为每个图像计算了综合视觉分级分析（VGAS）评分。对 IQFinv 和进行了归一化和比较。
对于所有标准，当直接在床上曝光探测器时，IQFinv 和 AUC-VGC 都明显优于将探测器放置在托盘上的所有曝光。在分为瘦和肥胖患者时，IQFinv 对于瘦患者显著降低，而 VGAS 评分则没有。对于肥胖患者，使用托盘时，两个数字都明显较低。
使用探测器托盘进行床边胸部成像会降低图像质量。
放射技师在使用带有集成托盘的设备时，应仔细评估图像质量，并通过实验确定最佳曝光因素。
