PT - JOURNAL ARTICLE AU - Deborah Tout AU - Ludovic Le Meunier AU - Sivakumar Muthu AU - Jérôme Declerck AU - Xiao-bo Pan AU - Christine Tonge AU - Parthiban Arumugam TI - Dose reduction in 3D Rb-82 cardiac PET perfusion imaging DP - 2012 May 01 TA - Journal of Nuclear Medicine PG - 1786--1786 VI - 53 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/53/supplement_1/1786.short 4100 - http://jnm.snmjournals.org/content/53/supplement_1/1786.full SO - J Nucl Med2012 May 01; 53 AB - 1786 Objectives PET systems operating in 3D mode offer a significant increased sensitivity compared to 2D systems and thus the opportunity to reduce injected dose while preserving image quality. This work studies the impact of a lower injected Rb-82 dose on the perfusion image quality in 3D cardiac imaging. Methods 40 patients referred for rest/stress Rb-82 myocardial perfusion scans were acquired on a Siemens mCT with TrueV (4 rings). 20 patients (BMI=31.1±5.3) were injected with 40 mCi (1480 MBq) and 20 patients (BMI=28.4±5.1) with 30 mCi (1110 MBq). Static and 8-bin ECG-gated perfusion images were reconstructed. Semi-quantitative scoring of image quality was performed by 2 experienced blinded observers. Wall/cavity contrast and contrast-to-noise ratio (CNR), and maximum to defect contrast were computed. Ejection fraction (EF) was also estimated with automatic quantification. Results Semi-quantitative analysis showed no difference in visual image quality for 40 mCi and 30 mCi studies. There was no significant difference in contrast and CNR between the 2 groups. The average contrast in static images (ECG-gated images in brackets - end diastolic frame) was 2.54±0.49 (2.96±0.57) for the 40 mCi group, and 2.60±0.43 (3.12±0.68) for the 30 mCi group (p=NS). The average CNR in static (gated) images was 4.30±0.96 (8.12±1.90) for the 40 mCi group and 4.58±1.95 (7.87±2.47) for the 30 mCi group (p=NS). Neither the maximum to defect contrast (1.63±0.27 with 40 mCi, 1.57±0.36 with 30 mCi) or the EF (70±16% with 40 mCi, 67±10% with 30 mCi) were significantly different between the 2 groups. Conclusions Administered activity can be reduced from 40 mCi to 30 mCi in clinical Rb-82 cardiac PET when using the Siemens mCT PET scanner, thereby reducing the effective dose to the patient by 25%, with no reduction in diagnostic quality of static and ECG-gated perfusion images