摘要
目的探讨多层螺旋 CT(MSCT)容积再现技术(VRT)显示肺气肿组织最佳的重组阈值区间,及其作为肺减容术(LVRS)靶区(拟行切除的肺气肿组织)显示手段的价值。方法对56例拟行 LVRS 的肺气肿患者行呼气相肺部扫描,按照 CT 检查时间的先后将患者分为 A 组和 B 组。以-1024～-960 HU、-1024～-910 HU 分别作为 LVRS 手术靶区的重组阈值区间,对 A 组的原始薄层图像行 VRT 重组,并将2种重组阈值的 VRT 图像分别与轴面图像、多平面重组(MPR)图像对比,确定显示 LVRS 靶区的最佳重组阈值区问。B 组根据 A 组选定的重组阈值区间进行 VRT 重组,计数并对比 VRT 与二维图像中直径≥3 cm 的肺大泡在各肺叶的分布,应用配对 t 检验验证2种计数结果。结果 A 组中以-1024～-960 HU 作为肺气肿重组阈值区间的 VRT 图像对 LVRS 手术靶区显示较佳,与相对正常肺组织对比较鲜明,病变的程度、范围与二维图像符合程度高。B 组中 VRT 图像与原始图像分析结果一致,对肺大泡的定位及计数结果与原始图像基本一致,肺右上、右中、右下、左上、左下叶计数对比,二维图像分别显示:(4.22±2.09)、(4.44±2.59)、(2.18±0.92)、(3.54±2.03)和(4.40±2.42)个;VRT 分别显示:(4.12±2.12)、(4.44±2.59)、(2.18±0.87)、(3.50±1.99)和(4.28±2.28)个(t 值分别为1.98、0.00、1.77、1.76、1.81,P 值均>0.05)。结论以-1024～-960 HU 作为肺气肿组织的重组阈值,VRT 成像可以准确显示肺气肿的分布类型,立体直观的显示 LVRS 手术靶区,为术前形态评估和术后效果预测提供了新方法。
Objective To investigate the optimal volume rendering technique（VRT） reconstruction threshold intervals using multislice spiral computed tomography （MSCT） , by which target areas of lung volume reduction surgery （LVRS） were well displayed. Methods Fifty-six patients with scheduled LVRS were examined using MSCT during expiration and subsequently divided into group A and group B. With reconstruction threshold intervals of- 1024 to -960 HU and - 1024 to -910 HU, respectively, VRT was applied to group A. Then the optimal threshold interval for target areas in LVR was determined. The determined threshold intervals of group A was applied to VRT reconstruction in group B and subsequently we counted and located bullae with diameters more than 3 cm on the resultant VRT images, analyzed the emphysema distribution types, and compared them with the findings on axial and multiple planar reform （MPR） images. Finally, the paired t- test was employed to assess the difference of bulla counting results between VRT and two-dimensional images. Results VRT reconstruction threshold intervals of - 1024 to - 960 HU was optimal in displaying the target areas in LVRS in group A. In group B, the distribution types of emphysema, the count and location of bullae on the resulting VRT images correlated well with source images （t = 1.98, 0. 00, 1.77, 1.76 and 1.81 ;P 〉0. 05 ）. The number of bullae in different lung lobes were ： 2 dimensional imges ： （ 4. 22 ± 2. 09）, （4.44 ± 2. 59 ）, （ 2. 18 ± O. 92）, （ 3.54 ± 2. 03 ） and （ 4. 40 ± 2.42） ,respectively ; VRT： （4. 12 ± 2. 12）,（4.44 ± 2.59）,（2. 18 ± 0.87） ,（3.50 ± 1.99）,（4.28 ± 2. 28）, respectively. The resultant VRT findings of LVRS patients were verified in operation. Conclusion VRT reconstruction threshold intervals of -1024 to -960 HU well displayed distribution types of emphysema and the target areas in LVRS, which provided a novel method of preoperative evaluation and postoperative outcome prediction.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2007年第11期1176-1179,共4页
Chinese Journal of Radiology
基金
湖北省科技厅科研基金(2003AA301C07)
关键词
肺气肿
肺切除术
体层摄影术
X线计算机
成像
三维
Pulmonary emphysema
Pneumonectomy
Tomography, X-ray computed
Imaging,three-dimensional
