Reproducibility

Cardiac PET

Statistics

Cardiology

Radiology

Coronary artery disease

Mathematics

Medicine

Nuclear medicine

Positron emission tomography

Journal of Nuclear Medicine

104 null Objectives: null null Cardiorespiratory and gross patient motion (GPM) during coronary PET imaging has a detrimental effect on quantitative uptake measurements. The combination of these different motion patterns can translate the lesions as much as 3cm. In this study, we present a novel triple motion correction method (3xMC) and evaluate the coronary PET quantitative test-retest reproducibility with and without 3xMC technique. null null Methods: null null The 3xMC technique utilized 4 ECG and 4 respiratory gates of coronary PET imaging with sodium fluoride (18F-NaF), while the number of GPM frames were acquisition dependent. Both respiratory and GPM were detected using data-driven techniques employing only the acquired PET list data. The motion was detected from center-of-mass evaluations (in 3D) of single-slice rebinned sinograms created for every 200ms of the acquisition. The respiratory motion was extracted from the diaphragm only, while the GPM was evaluated for the entire PET field-of-view. For evaluation, 20 patients with coronary artery disease who underwent repeated hybrid 18F-NaF PET/CTA imaging within 3 weeks were analyzed with and without 3xMC technique. Two datasets were reconstructed, a standard end-diastolic dataset with 25% of the total counts (Standard) and a 3xMC dataset. Coronary lesions were identified on CTA images in arteries with diameter ≥2mm, with stenosis of >25% in the coronary segment and no prior stents. Lesion uptake was quantified from spherical Volume of Interests (VOIs) (radius=5mm), while background activities were obtained in the right atrium using a cylindrical VOI (length=15mm, radius=10mm). Lesions with Target to background (TBR) ≥1.25 were considered 18F-NaF avid, while lesions with TBR <1.25 were considered 18F-NaF negative. We report TBR and signal to noise ratios (SNR) for all image sets. Test-retest reproducibility of TBR was assessed by Bland-Altman analysis and coefficient of reproducibility. null Results: null null A total of 47 unique coronary lesions (15 18F-NaF-avid) were identified on CTA. Increased TBR values were reported for all lesions (Standard = 1.18±0.48, 3xMC=1.20±0.48, p=0.12) and in sub-analyzes of 18F-NaF-avid lesions only (Standard=1.65±0.38, 3xMC=1.68±0.29, p=0.26), though non-significant. Reduced noise (increased SNR) was reported for all lesions datasets following 3xMC (Standard = 10.95±6.00, 3xMC = 13.23±9.51, p 10mm following corrections reproducibility was improved by 53.8% (coefficient of reproducibility: standard= 0.745, 3xMC= 0.484). In addition, 4 lesions were reclassified following 3xMC (Figure 2). null null Conclusions: null null Combined corrections for cardiac, respiratory and gross patient motion improve test-retest reproducibility of coronary 18F-NaF PET.

Triple motion correction including cardiorespiratory and gross patient motion: application in coronary plaque imaging using PET