Nishio Mizuho, Matsumoto Sumiaki, Seki Shinichiro, Koyama Hisanobu, Ohno Yoshiharu, Fujisawa Yasuko, Sugihara Naoki, Yoshikawa Takeshi, Sugimura Kazuro
Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan; Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
Eur J Radiol. 2014 Dec;83(12):2268-2276. doi: 10.1016/j.ejrad.2014.09.011.
To evaluate the effects of adaptive iterative dose reduction using 3D processing (AIDR 3D) for quantification of two measures of emphysema: percentage of low-attenuation volume (LAV%) and size distribution of low-attenuation lung regions.
Fifty-two patients who underwent standard-dose (SDCT) and low-dose CT (LDCT)were included. SDCT without AIDR 3D, LDCT without AIDR 3D, and LDCT with AIDR 3D were used for emphysema quantification. First, LAV% was computed at 10 thresholds from −990 to −900 HU. Next, at the same thresholds, linear regression on a log–log plot was used to compute the power law exponent (D)for the cumulative frequency-size distribution of low-attenuation lung regions. Bland–Altman analysis was used to assess whether AIDR 3D improved agreement between LDCT and SDCT for emphysema quantification of LAV% and D.
The mean relative differences in LAV% between LDCT without AIDR 3D and SDCT were 3.73%–88.18% and between LDCT with AIDR 3D and SDCT were −6.61% to 0.406%. The mean relative differences in D between LDCT without AIDR 3D and SDCT were 8.22%–19.11% and between LDCT with AIDR3D and SDCT were 1.82%–4.79%. AIDR 3D improved agreement between LDCT and SDCT at thresholds from −930 to −990 HU for LAV% and at all thresholds for D.
AIDR 3D improved the consistency between LDCT and SDCT for emphysema quantification of LAV% and D.
评估使用三维处理的自适应迭代剂量降低技术(AIDR 3D)对两种肺气肿测量指标进行定量分析的效果,这两种指标分别为低衰减体积百分比(LAV%)和低衰减肺区域的大小分布。
纳入52例行标准剂量CT(SDCT)和低剂量CT(LDCT)检查的患者。使用未采用AIDR 3D的SDCT、未采用AIDR 3D的LDCT以及采用AIDR 3D的LDCT进行肺气肿定量分析。首先,在-990至-900 HU的10个阈值处计算LAV%。接下来,在相同阈值下,使用对数-对数图上的线性回归计算低衰减肺区域累积频率-大小分布的幂律指数(D)。采用Bland-Altman分析评估AIDR 3D是否改善了LDCT与SDCT在LAV%和D的肺气肿定量分析方面的一致性。
未采用AIDR 3D的LDCT与SDCT之间LAV%的平均相对差异为3.73%至88.18%,采用AIDR 3D的LDCT与SDCT之间LAV%的平均相对差异为-6.61%至0.406%。未采用AIDR 3D的LDCT与SDCT之间D的平均相对差异为8.22%至19.11%,采用AIDR 3D的LDCT与SDCT之间D的平均相对差异为1.82%至4.79%。对于LAV%,AIDR 3D在-930至-990 HU的阈值下改善了LDCT与SDCT之间的一致性;对于D,在所有阈值下均有改善。
AIDR 3D改善了LDCT与SDCT在LAV%和D的肺气肿定量分析方面的一致性。