摘要
目的评价数字断层融合（DTS）技术及MSCT胸部扫描对肺结节的检出率及辐射剂量水平。方法采用DTS及MSCT分别扫描共置入45个肺模拟结节及热释光剂量计（TLD）的胸部体模，记录并储存图像，测量胸部主要组织器官的吸收剂量并计算有效剂量。采用Fisher确切概率法（样本数小于30）和χ2检验，比较DTS与MSCT扫描对模拟结节检出率的差别；两种检查方法器官吸收剂量的比较采用配对t检验。结果DTS与MSCT对肺结节的检出率分别为66．7％（30／45）和91．1％（41／45），差异有统计学意义（χ2=8．073，P〈0．05）；对CT值为-650HU的磨玻璃结节检出率分别为73．3％（11／15）和93．3％（14／15），差异无统计学意义（P〉0．05）。DTS对CT值为-800HU及直径〈8mm的磨玻璃结节检出率分别为33．3％（5／15）和16．7％（2／12），MSCT的检出率分别为80．0％（12／15）和66．7％（8／12），两者差异均有统计学意义（P〈0．05）。胸部DTS检查各主要组织器官（肺、胸椎、心脏、肝脏、乳腺和甲状腺）的吸收剂量明显低于MSCT，两者差异有统计学意义（上述部位的t值分别为19．69、30．01、16．33、5．06、9．43和8．05，P值均〈0．05）。DTS与MSCT胸部扫描的有效剂量分别为0．65和7．71mSv。结论DTS对于CT值为-650HU的磨玻璃结节检出率与MSCT相近，对极低密度（-800HU）磨玻璃结节及直径〈8mm的磨玻璃结节检出率低。肺部结节检查时，DTS有效剂量低于MSCT，约为MSCT辐射剂量的8．41％。
Objective To compare detection rate of pulmonary nodules and the radiation doses of digital tomosynthesis （DTS） and MSCT chest scanning by using the anthropomorphic chest phantom which contains thermoluminescent dosimeters （ TLD ） and simulated pulmonary nodules. Methods The radiation doses of DTS and MSCT scanning were measured by using the anthropomorphic chest phantom which contains 45 TLD and simulated pulmonary nodules. The radiation doses of major organs were converted into effective dose （ED）. Three radiologists of different clinical experiences independently reviewed and recorded the density, diameter and position of pulmonary nodules. The sensitivity of nodule detection by DTS and MSCT were compared by Fisher exact test and Chi-square test. The paired t test was conducted to analyze the dose levels of DTS and MSCT. Results The sensitivity of detection nodule by DTS and MSCT were 66. 7% （30/45） and 91.1% （41/45） respectively. Statistically significant difference between the two examinations existed （ χ2 = 8. 073, P 〈 0. 05 ）. The sensitivity of detection - 650 HU ground glass opacity pulmonary nodule by MSCT and DTS were 93.3% （14/15） and 73.3% （11/15） respectively. There was no significant difference between DTS and MSCT （ P 〉 0. 05 ）. The sensitivity of detection - 800 HU ground glass opacity nodule and ground glass opacity nodule （d 〈8 mm） by DTS were 33.3% （5/15） and 16. 7% （2/12） respectively, which were lower than those by CT[80. 0% （12/15） and 66. 7% （8/12） ]. The radiation doses of DTS for various organs in the chest were lower than those of CT. Statistical significant difference between DTS and MSCT existed （ lung t = 19.69, thoracic vertebral t = 30. 0!, heart t = 16. 33, liver t = 5.06, breast t = 9.43,thyroid gland t = 8.05 ;P 〈 0. 05 ）. The effective doses of the DTS and MSCT were 0. 65 and 7.71 mSv respectively. Conclusions There is no difference between the DTS and MSCT in the detection rate of -650 HU ground glass opacity nodule. For detecting the ground glass opacity nodule （ - 800 HU） and ground glass opacity nodule （ d 〈 8 mm）, MSCT is superior to DTS. However, the radiation dosage of DTS is 8.41% of the MSCT scanning.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2012年第4期363-366,共4页
Chinese Journal of Radiology
基金
基金项目：重庆市卫生局科研基金资助项目（08-2-29）
