PT  - JOURNAL ARTICLE
AU  - Pascal Koepfli
AU  - Thomas F. Hany
AU  - Christophe A. Wyss
AU  - Mehdi Namdar
AU  - Cyrill Burger
AU  - Alexander V. Konstantinidis
AU  - Thomas Berthold
AU  - Gustav K. von Schulthess
AU  - Philipp A. Kaufmann
TI  - CT Attenuation Correction for Myocardial Perfusion Quantification Using a PET/CT Hybrid Scanner
DP  - 2004 Apr 01
TA  - Journal of Nuclear Medicine
PG  - 537--542
VI  - 45
IP  - 4
4099  - http://jnm.snmjournals.org/content/45/4/537.short
4100  - http://jnm.snmjournals.org/content/45/4/537.full
SO  - J Nucl Med2004 Apr 01; 45
AB  - In routine PET, a 10- to 20-min transmission scan with a rotating 68Ge 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: 13N-labeled NH3 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 68Ge 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 68Ge 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 68Ge AC was compared with emission reconstructed with CT AC at any of the different tube currents. Only emission without any correction differed significantly from 68Ge 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 68Ge ACFBP was compared with 68Ge ACIT (RC = 0.218) and when CT ACFBP was compared with CT ACIT (RC = 0.227). Even better reproducibility (lower RC) was found when 68Ge ACFBP was compared with CT ACFBP (RC = 0.130) and when 68Ge ACIT was compared with CT ACIT (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 68Ge AC provides accurate results.