Title:Impact of MRI-based Segmentation Artifacts on Amyloid- and FDG-PET Quantitation
Volume: 13
Issue: 5
Author(s): Marcus Högenauer, Matthias Brendel, Andreas Delker, Sonja Därr, Mayo Weiss, Peter Bartenstein, Axel Rominger and Alzheimer’s Disease Neuroimaging Initiative
Affiliation:
关键词:
淀粉正电子发射断层扫描,人工产品,氟脱氧葡萄糖正电子发射断层扫描,掩蔽,核磁共振成像,部分容积效应校正,分割。
摘要: Introduction: Magnet resonance image (MRI)-based segmentations are widely used for
clinical brain research, especially in conjunction with positron-emission-tomography (PET). Although
artifacts due to segmentation errors arise commonly, the impact of these artifacts on PET quantitation
has not yet been investigated systematically. Therefore, the aim of this study was to assess the effect
of segmentation errors on [18F]-AV45 and [18F]-FDG PET quantitation, with and without correction
for partial volume effects (PVE). Material and Methods: 119 subjects with both [18F]-AV45, and
[18F]-FDG PET as well as T1-weighted MRI at baseline and at two-year follow-up were selected from
the ADNI cohort, and their MRI brain images were segmented using PMOD 3.5. MRIs with segmentation
artifacts were masked with the corresponding [18F]-FDG PET standard-uptake-value (SUV) images to elucidate and
quantify the impact of artifacts on PET analyses for six defined volumes-of-interest (VOI). Artifact volumes were calculated
for each VOI, together with error-[%] and root-mean-square-errors (RMSE) in uncorrected and PVE corrected SUV
results for the two PET tracers. We also assessed the bias in longitudinal PET data. Results: Artifacts occurred most frequently
in the parietal cortex VOI. For [18F]-AV45 and [18F]-FDG PET, the percentage-errors were dependent on artifact
volumes. PVEC SUVs were consequently more distorted than were their uncorrected counterparts. In static and longitudinal
assessment, a small subgroup of subjects with large artifacts (≥1500 voxels; ≙5.06 cm³) accounted for much of the
PET quantitation bias. Conclusion: Large segmentation artifacts need to be detected and resolved as they considerably bias
PET quantitation, especially when PVEC is applied to PET data.