Adrenal lesions: attenuation measurement differences between CT scanners.
Adrenal lesions: attenuation measurement differences between CT scanners.
复制标题
肾上腺病变：CT 扫描仪之间的衰减测量差异。
作者：
P. Hahn;M. Blake;G. Boland
目的
回顾性比较使用两个不同制造商的多探测器扫描仪获得的相同肾上腺病变的未增强计算机断层扫描，以评估衰减测量是否存在差异。
材料和方法
该研究得到了当地伦理委员会的批准，并放弃了患者的同意，并且是按照 HIPAA 进行的。电子搜索显示，2000 年 1 月至 2004 年 9 月期间，使用西门子 16 探测器行扫描仪和 GE 医疗系统 8 台多探测器行扫描仪之一对患有肾上腺结节的患者进行了扫描，未使用静脉造影剂。通过使用组织学结果、脂肪含量或大小稳定性来表征病变。除非两次扫描是在 21 天内获得的，否则需要 6 个月的尺寸稳定性。两名放射科医生独立测量病灶衰减以进行回归分析。分别分析一次扫描中被认为是良性（<或= 10 HU）的病变和另一次扫描中被认为是不确定（> 10 HU）的病变，并比较扫描的技术参数。
结果
47 名患者（27 名男性，20 名女性；年龄范围，40-86 岁；平均年龄，64 岁）有 4 个转移瘤、42 个腺瘤和 1 个骨髓脂肪瘤（长轴长度，10-85 mm；平均年龄，24 mm）。 GE 扫描是通过四探测器行扫描仪 (n = 32)、八探测器行扫描仪 (n = 2) 和 16 探测器行扫描仪 (n = 13) 获得的。对于西门子和 GE 扫描衰减测量，两个读数器之间的相关性均为 0.99。两个读者绘制 GE 衰减（y 轴）与西门子衰减（x 轴）的回归线的斜率小于 1，这表明 GE 扫描的衰减比西门子扫描的衰减有轻微但具有统计学意义的趋势。对于两位读者，西门子扫描中存在更多的不确定病变（> 10 HU），但 GE 扫描中的良性病变（< 或 = 10 HU）多于相反情况（麦克尼马尔检验，对于读者 1，P < .02，对于读者 2 不显着）。平均西门子和GE扫描技术参数相似。
结论
使用不同扫描仪获得的扫描测量的肾上腺结节的衰减仅存在轻微差异。
PURPOSE
To retrospectively compare unenhanced computed tomographic scans of the same adrenal lesion obtained with two different manufacturers' multidetector scanners to assess whether there are differences in attenuation measurements.
MATERIALS AND METHODS
The study was approved by the local ethical committee, which waived patient consent, and was conducted in compliance with HIPAA. Electronic searching revealed patients with adrenal nodules scanned with both a Siemens 16-detector row scanner and one of eight GE Medical Systems multi-detector row scanners between January 2000 and September 2004 without the use of intravenous contrast material. Lesions were characterized by using histologic findings, fat content, or size stability. Size stability for 6 months was required unless both scans were obtained within 21 days of each other. Two radiologists independently measured lesion attenuation for regression analysis. Lesions considered benign (< or = 10 HU) on one scan and indeterminate (> 10 HU) on the other were separately analyzed, and technical parameters of scanning were compared.
RESULTS
There were 47 patients (27 men, 20 women; age range, 40-86 years; mean age, 64 years) with four metastases, 42 adenomas, and one myelolipoma (long-axis length, 10-85 mm; mean, 24 mm). GE scans were obtained with four-detector row scanners (n = 32), an eight-detector row scanner (n = 2), and 16-detector row scanners (n = 13). Correlation between the two readers was 0.99 for both Siemens and GE scan attenuation measurements. The slope of regression lines for both readers plotting GE attenuation (y-axis) against Siemens attenuation (x-axis) was less than 1, which indicated a slight but statistically significant tendency for GE scans to have lower attenuations than do Siemens scans. For both readers, there were more lesions indeterminate (> 10 HU) on Siemens scans but benign (< or = 10 HU) on GE scans than the reverse (McNemar test, P < .02 for reader 1, not significant for reader 2). Average Siemens and GE scan technical parameters were similar.
CONCLUSION
There are only slight differences in attenuation of adrenal nodules measured on scans obtained with different scanners.