Comparison of quantitative [11C]PE2I PET scans acquired on PET/MR and stand-alone PET

• Dedicated PET systems using transmission-based attenuation correction (AC) are regarded as the gold standard for quantitative brain PET. PET/MR systems demanded great efforts for accurate AC but differences in technology, geometry and hardware attenuation may also affect quantitative results. This study compares PET quantitative outcomes between a stand-alone PET and PET/MR scanner. Ten patients with parkinsonism underwent two 80-min dynamic PET scans with the dopamine transporter ligand [11C]PE2I. Images were reconstructed using resolution-matched settings and transmission scans (stand-alone PET) and zero-echo-time (PET/MR) for AC. SUV, relative delivery (R1), and dopamine transporter availability (BPND) were compared on a VOI- and voxel-basis.  Correlations between systems were high (≥ 0.85) for all quantitative parameters. On VOI-basis, striatal BPND was significantly lower on PET/MR than on stand-alone PET (-7%). R1 was significantly overestimated in posterior cortical regions (9%) and underestimated in striatal (-9%) and limbic areas (-6%). SUV showed a similar pattern as R1. Voxel-by-voxel analysis showed significant positive bias of R1 in the auditory cortex. PET/MR significantly underestimated striatal BPND, similar to previously reported [11C]PE2I BPND  test-retest variability. The acoustic noise in the PET/MR environment may attribute to an overestimation of R1 in the auditory cortex, which needs consideration when using PET/MR data.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Radiologi och bildbehandling (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Radiology, Nuclear Medicine and Medical Imaging (hsv//eng)

Nyckelord

Attenuation correction; Dopamine transporter; Hybrid imaging; Acoustic MR noise; parkinsonism

Medicinsk radiofysik

Medical Radiophysics

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