VARIABILITY IN MEASUREMENT OF ABDOMINAL AORTIC-ANEURYSMS
VARIABILITY IN MEASUREMENT OF ABDOMINAL AORTIC-ANEURYSMS
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DOI：
10.1016/s0741-5214(95)70222-9
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发表时间：
1995-06-01
影响因子：
4.3
通讯作者：
ANSEL, HJ
中科院分区：
文献类型：
--
作者：
LEDERLE, FA;WILSON, SE;ANSEL, HJ
目的：本研究的目的是报告在一项大型、多中心、随机试验中观察到的腹主动脉瘤（AAA）直径的CT测量在观察者之间和观察者内部的变异性，以及CT和超声检查之间的一致性。方法：将参与中心的AAA直径的CT测量结果与中心实验室的相同扫描结果进行比较。对随机选择的CT扫描子集进行盲法中心再测量，以评估观察者内部的变异性。还评估了30天内CT和超声测量AAA的一致性。结果：对于观察者间对AAA直径的局部和中心CT测量（n = 806）， 65%的对差异为0.2 cm或更小，但17%的对差异至少为0.5 cm。对于中心CT重新测量的观察者对（n = 70）， 90%的误差在0.2 cm以内，70%在0.1 cm以内，只有一个误差在0.5 cm以内。在258对超声测量和中心CT中，44%的差异小于0.2 cm， 33%的差异大于0.5 cm。超声测量值比中央CT测量值平均小0.27 cm （p < 0.0001）。局部CT和超声测量显示明显倾向于记录半厘米。结论：CT测量AAA直径具有较高的精度，但由于测量技术的差异，在实际应用中可能无法达到这种精度。成像方式之间的差异进一步增加了可变性。AAA测量值0.5 cm或以上的变化并不罕见，在管理决策中应考虑到这一点。减少测量差异的努力是有必要的，可能包括(1)寻求外科医生和放射科医生就AAA直径的精确定义达成一致，(2)限制测量AAA的放射科医生的数量，(3)使用卡尺和放大镜进行CT测量。
Purpose: The purpose of this study was to report interobserver and intraobserver variability of computed tomography (CT) measurements of abdominal aortic aneurysm (AAA) diameter and agreement between CT and ultrasonography observed in the course of a large, multicenter, randomized trial on the management of small AAAs.Methods: CT measurements of AAA diameter from participating centers were compared with measurements made from the same scan by a central laboratory. Blinded central remeasurement of a randomly selected subset of these CT scans was used to assess intraobserver variability. Agreement between AAA measurements by CT and ultrasonography done within 30 days of each other was also assessed.Results: For interobserver pairs of local and central CT measurements of AAA diameter (n = 806), the difference was 0.2 cm or less in 65% of pairs, but 17% differed by at least 0.5 cm. For intraobserver pairs of central CT remeasurements (n = 70), 90% differed by 0.2 cm or less, 70% were within 0.1 cm, and only one differed by 0.5 cm. Of 258 ultrasound-measured and central CT pairs, the difference was 0.2 cm or less in 44% and at least 0.5 cm in 33%. Ultrasound measurements were smaller than central CT measurements by an average of 0.27 cm (p < 0.0001). Local CT and ultrasound measurements showed a marked preference for recording by half centimeter.Conclusions: A high degree of precision is possible in CT measurement of AAA diameter, but this precision may not be obtained in practice because of differences in measurement techniques. Differences between imaging modalities increase variability further. Variations in AAA measurement of 0.5 cm or more are not uncommon, and this should be taken into account in management decisions. Efforts to reduce variation in measurement are warranted and might include (1) seeking agreement between surgeons and radiologists on a precise definition of AAA diameter, (2) limiting the number of radiologists who measure AAAs, and (3) use of calipers and magnifying glass for CT measurements.