使用PET/CT混合扫描仪进行心肌灌注定量的CT衰减校正。

CT attenuation correction for myocardial perfusion quantification using a PET/CT hybrid scanner.

作者信息

Koepfli Pascal, Hany Thomas F, Wyss Christophe A, Namdar Mehdi, Burger Cyrill, Konstantinidis Alexander V, Berthold Thomas, Von Schulthess Gustav K, Kaufmann Philipp A

机构信息

Nuclear Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland.

出版信息

J Nucl Med. 2004 Apr;45(4):537-42.

PMID:15073247

Abstract

UNLABELLED

In routine PET, a 10- to 20-min transmission scan with a rotating (68)Ge source is commonly obtained for attenuation correction (AC). AC is time-consuming using this procedure and could considerably be shortened by instead using a rapid CT scan. Our aim was to evaluate the feasibility of CT AC in quantitative myocardial perfusion PET using a hybrid PET/CT scanner.

METHODS

(13)N-labeled NH(3) and PET were used to measure myocardial blood flow (MBF) (mL/min/g) at rest and during standard adenosine stress. In group 1 (n = 7), CT scans (0.5 s) of the heart area with different tube currents (10, 40, 80, and 120 mA) were compared with a standard (68)Ge transmission (20 min) and with no AC. In group 2 (n = 3), the repeatability of 8 consecutive CT scans at a tube current of 10 mA was assessed. In group 3 (n = 4), emission was preceded and followed by 3 CT scans (10 mA) and 1 (68)Ge scan for each patient. For reconstruction, filtered backprojection (FBP) was compared with iterative reconstruction (IT).

RESULTS

For group 1, no significant difference in mean MBF for resting and hyperemic scans was found when emission reconstructed with (68)Ge AC was compared with emission reconstructed with CT AC at any of the different tube currents. Only emission without any correction differed significantly from (68)Ge AC. For group 2, repeated measurements revealed a coefficient of variance ranging from 2% to 5% and from 2% to 6% at rest and at stress, respectively. For group 3, similar reproducibility coefficients (RC) for MBF were obtained when (68)Ge AC(FBP) was compared with (68)Ge AC(IT) (RC = 0.218) and when CT AC(FBP) was compared with CT AC(IT) (RC = 0.227). Even better reproducibility (lower RC) was found when (68)Ge AC(FBP) was compared with CT AC(FBP) (RC = 0.130) and when (68)Ge AC(IT) was compared with CT AC(IT) (RC = 0.146).

CONCLUSION

Our study shows that for the assessment of qualitative and quantitative MBF with a hybrid PET/CT scanner, the use of CT AC (with a tube current of 10 mA) instead of (68)Ge AC provides accurate results.

摘要

未标记

在常规正电子发射断层扫描（PET）中，通常使用旋转的（68）锗源进行10至20分钟的透射扫描以进行衰减校正（AC）。使用此程序进行AC很耗时，而改用快速CT扫描可以大大缩短时间。我们的目的是评估在使用PET/CT混合型扫描仪进行定量心肌灌注PET中CT AC的可行性。

方法

使用（13）N标记的氨和PET来测量静息和标准腺苷负荷状态下的心肌血流量（MBF）（毫升/分钟/克）。在第1组（n = 7）中，比较了不同管电流（10、40、80和120毫安）下心脏区域的CT扫描（0.5秒）与标准的（68）锗透射扫描（20分钟）以及不进行AC的情况。在第2组（n = 3）中，评估了在10毫安管电流下连续8次CT扫描的可重复性。在第3组（n = 4）中，对每位患者在发射扫描之前和之后分别进行3次CT扫描（10毫安）和1次（68）锗扫描。对于重建，将滤波反投影（FBP）与迭代重建（IT）进行了比较。

结果

对于第1组，在任何不同管电流下，当将用（68）锗AC重建的发射图像与用CT AC重建的发射图像进行比较时，静息和充血扫描的平均MBF均无显著差异。只有未进行任何校正的发射图像与（68）锗AC有显著差异。对于第2组，重复测量显示静息和负荷状态下的变异系数分别为2％至5％和2％至6％。对于第3组，当比较（68）锗AC（FBP）与（68）锗AC（IT）时（RC = 0.218）以及当比较CT AC（FBP）与CT AC（IT）时（RC = 0.227），获得了相似的MBF重现性系数（RC）。当比较（68）锗AC（FBP）与CT AC（FBP）时（RC = 0.130）以及当比较（68）锗AC（IT）与CT AC（IT）时（RC = 0.146），发现重现性更好（RC更低）。