Lambruschi G, Tagliagambe A, Palla L, Torri T, D'Alessandro F, Pastori R, Barbieri L
Istituto di Radiologia, Ospedale Civile di Carrara.
Radiol Med. 1993 Jan-Feb;85(1-2):59-64.
Conventional and digital mammographic images obtained with storage phosphors were compared. The digital images were acquired with high-resolution 3rd-generation (HR III) screens and specifically adapted algorithms. The experience was made both on a phantom and in vivo. The phantom study was carried out by comparing conventional with digital radiographs acquired with: a) same kV (28) and same mAs; b) same kV (24) and same mAs; c) 28 kV with 30% mAs reduction, in digital images only. The results obtained upon counting the amount of recognizable details per image demonstrated slight loss of information in digital radiographs only when mAs was reduced by 30%. Two hundred patients were studied; they were divided into four groups according to the type of breast (medium inherent contrast or solid breast) and to exposure factors. After conventional mammography, an additional digital radiograph was performed using one of the three techniques previously employed on the phantom. Separately, 10 ductogalactographies and 10 magnification radiographs of microcalcifications were compared; the same exposure factors were used in these images too. The radiographs were viewed by three expert mammographic radiologists; contrast quality and spatial resolution were investigated and a score was given to each image on a 3-grade scale (insufficient, sufficient, good). The comparison of the mean values obtained showed higher contrast and better enhancement of nodular lesions on digital images, on which, however, the depiction of microcalcifications was worse than on conventional radiographs, especially with lower radiation doses, even though the number of detected microcalcifications was the same.
对使用存储磷光体获得的传统乳腺钼靶图像和数字乳腺钼靶图像进行了比较。数字图像是使用高分辨率第三代(HR III)屏幕和专门适配的算法采集的。在体模和体内均进行了相关实验。体模研究通过比较以下方式获得的传统射线照片和数字射线照片来进行:a)相同千伏(28)和相同毫安秒;b)相同千伏(24)和相同毫安秒;c)仅在数字图像中采用28千伏且毫安秒降低30%。通过计算每张图像中可识别细节的数量得出的结果表明,仅当毫安秒降低30%时,数字射线照片中的信息会有轻微损失。对200名患者进行了研究;根据乳房类型(中等固有对比度或实性乳房)和曝光因素将他们分为四组。在进行传统乳腺钼靶检查后,使用之前在体模上采用的三种技术之一额外进行了一次数字射线摄影。另外,对10例导管造影术和10例微钙化放大射线照片进行了比较;这些图像也使用了相同的曝光因素。由三位专业乳腺钼靶放射科医生查看这些射线照片;研究了对比度质量和空间分辨率,并以三级量表(不足、足够、良好)对每张图像进行评分。所得平均值的比较显示,数字图像上结节性病变的对比度更高且增强效果更好,然而,数字图像上微钙化的显示比传统射线照片差,尤其是在较低辐射剂量下,尽管检测到的微钙化数量相同。