Karabulut Nevzat, Törü Mustafa, Gelebek Veli, Gülsün Meltem, Ariyürek O Macit
Department of Radiology, Hacettepe University Medical Center, Ankara, Turkey.
Eur Radiol. 2002 Nov;12(11):2764-9. doi: 10.1007/s00330-002-1368-4. Epub 2002 Apr 18.
The purpose of this study was to investigate the diagnostic accuracy of low-dose helical computed tomography by comparing the number of nodules detected at low- and standard-dose CT. The prospective study included 25 patients who were referred to CT scan for the assessment of pulmonary metastases. All patients underwent CT examinations at both standard- (200 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation) and low-dose (50 mA, 120 kV, collimation 5 mm, table feed 10 mm per rotation). The number of nodules detected at each protocol was recorded. The size of the nodules was measured electronically and categorized as <3, 3-4.9, 5-6.9, 7-9.9, and >/=10 mm. Finally, the nodules detected at only standard- or low-dose CT were assessed for the underlying causes of discrepancy. In 25 patients, 533 nodules were detected at standard-dose, whereas 518 nodules were observed at low-dose CT. There were no statistically significant differences in the number of nodules detected at standard- or low-dose CT ( p>0.05). Four hundred ninety-one (87.7%) nodules were detected at both standard- or low-dose CT, 42 (7.5%) nodules were observed only at standard-dose CT, and 27 (4.8%) nodules were seen only at low-dose CT. The sensitivity of low-dose CT was 92.5% for all nodules, 88.1% for nodules <5 mm, and 97.4% for nodules >/=5 mm. No significant image artifact interfering with nodule detection was observed at low-dose CT. The low-dose CT protocol used in this study provided images of adequate quality; thus, it can be used reliably in the detection or exclusion of pulmonary nodules.
本研究的目的是通过比较低剂量和标准剂量CT检测到的结节数量，探讨低剂量螺旋计算机断层扫描的诊断准确性。这项前瞻性研究纳入了25例因评估肺转移而接受CT扫描的患者。所有患者均接受了标准剂量（200 mA，120 kV，准直5 mm，每旋转床进10 mm）和低剂量（50 mA，120 kV，准直5 mm，每旋转床进10 mm）的CT检查。记录每个方案检测到的结节数量。通过电子方式测量结节大小，并将其分类为<3、3 - 4.9、5 - 6.9、7 - 9.9和≥10 mm。最后，对仅在标准剂量或低剂量CT上检测到的结节进行差异潜在原因评估。在25例患者中，标准剂量CT检测到533个结节，而低剂量CT观察到518个结节。标准剂量或低剂量CT检测到的结节数量在统计学上无显著差异（p>0.05）。491个（87.7%）结节在标准剂量和低剂量CT上均被检测到，42个（7.5%）结节仅在标准剂量CT上观察到，27个（4.8%）结节仅在低剂量CT上被看到。低剂量CT对所有结节的敏感性为92.5%，对<5 mm结节的敏感性为88.1%，对≥5 mm结节的敏感性为97.4%。在低剂量CT上未观察到干扰结节检测的明显图像伪影。本研究中使用的低剂量CT方案提供了质量足够的图像；因此，它可可靠地用于肺结节的检测或排除。
