Introduction
Methods
Patient and scan information
Software packages
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MIM Software’s MIMneuro (https://www.mimsoftware.com/nuclear_medicine/mim_neuro)
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Syntermed’s NeuroQ (https://www.syntermed.com/neuroq)
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Hermes Medical Solutions’ BRASS (https://www.hermesmedical.com/neurology/)
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GE Healthcare’s CortexID (https://www.gehealthcare.com/courses/aw-cortex-id)
– | MIM software’s MIMneuro | Syntermed’s NeuroQ | Hermes medical solutions’ BRASS | GE healthcare’s CortexID |
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CE/FDA status | CE Mark and FDA 510(k) | CE Mark and FDA 510(k) | FDA 510(k) | FDA 510(k) |
Imaging requirements | PET, optional MRI or CT | PET, optional MR or CT | PET, optional MRI or CT | PET, optional MRI or CT |
Normative database | 54 controls | 25 controls | 80 controls [48] | > 100 controls |
QC procedure | Visual QC for registration quality | |||
Partial volume correction | Not performed | |||
Spatial normalisation | Standard space (MNI) | |||
Attenuation correction | Required for image acquisition and processing | |||
Reference regions | Customizable e.g. pons, whole cerebellum, cerebellar cortex | Pons, whole cerebellum | Pons, whole cerebellum, cerebellar cortex | Pons, whole cerebellum, cerebellar cortex |
Target regions available in addition to harmonised mask | Customizable e.g. Left/right hemisphere for: anterior cingulate gyrus, inferior medial frontal gyrus, lateral temporal lobe, posterior cingulate gyrus, precuneus, and superior parietal lobule | Left/right hemisphere for all (except midbrain and vermis): frontal cortex, sensorimotor cortex, broca’s region, anterior cingulate, posterior cingulate, caudate nucleus, lentiform nucleus, thalamus, parietal cortex, parietotemporal cortex, lateral temporal cortex, medial temporal cortex, primary visual cortex, associative visual cortex, midbrain, and vermis | Left/right hemisphere for all: frontal cortex, anterior cingulate, occipital cortex parietal cortex, lateral temporal cortex, precuneus/posterior cingulate, | Left/right hemisphere for all: Prefrontal, anterior cingulate, precuneus/posterior cingulate, parietal, lateral/mesial temporal, occipital, sensorimotor |
Metrics reported | SUVr, z-score, Centiloid* | SUVr, z-score | SUVr, z-score | SUVr, z-score |
Normative database demographics
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Cortex ID The [18F]flutemetamol normal database of 100 amyloid negative scans spans the age range from 30 to 85 years with the majority of the subjects being 55 years old and above. Amyloid load as measured by amyloid PET in amyloid negative controls has a very weak association with subject age and thus no age correction of the normal database was deemed necessary
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BRASS database of 80 subjects is a subset of the 100 contained in CortexID
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NeuroQ normal data base consists of [.18F]flutemetamol scans from 25 cognitively unimpaired subjects (10 < 55 years and 15 > 55 years) [46]
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MIMneuro The [18F]flutemetamol normal database contains 54 exams from AIBL. Exams were classified as normal according to AIBL criteria and have a negative amyloid scan upon visual assessment. Ages span from 60 to 84 years old.
Image processing
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BRASS using v2.10.1.0, by HP/PT (GE Healthcare, Amersham, UK). The BRASS GUI loads in DICOM folders, the correct tracer/reference region must be selected and then registration initiated. Registrations were visually checked and quantitative results were then exported for analysis.
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CortexID using v2.1 Ext. 6, by VP (GE Healthcare, Marlborough, USA). The CortexID GUI requires DICOM import, image registration automatically follows and quality was checked visually. SUVr results were then exported for analysis.
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MIMneuro using vMIM-7.2.1 LA21-01, by WB/KH (MIMSoftware, Ohio, USA). The MIMneuro GUI requires DICOM import. The tracer is detected automatically from DICOM headers, and the reference region is selected based on the tracer. Registration is both rigid and deformable. Registrations were checked visually and results exported for analysis.
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NeuroQ using v3.80, by HP/PT (GE Healthcare, Amersham, UK). The NeuroQ GUI requires import of patient’s DICOM, and selection of reference region and appropriate tracer database. Both rigid and nonlinear registration were then performed and visually quality checked. Next, composite SUVr was generated and databased.
Pilot data processing
Validation data processing
Statistical analysis
Assessment of SUVr(pons) values relative to visual inspection
Results
Pilot data compatibility
– | SW 2 Original | SW 4 Original | SW 4 ∆ SW 2 Original | SW 3 Original | SW 3 ∆ SW 2 Original | SW 3 Harmonised | SW 3 ∆ SW 2 Harmonised | SW 1 Original | SW 1 ∆ SW 2 Original | SW 1 Harmonised | SW 1 ∆ SW 2 Harmonised |
---|---|---|---|---|---|---|---|---|---|---|---|
Mean composite SUVr | 0.663 | 0.639 | − 0.024 | 0.724 | 0.061 | 0.660 | − 0.003 | 0.735 | 0.073 | 0.689 | 0.026 |
Pilot data with harmonized cortical mask
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Software 3 vs Software 2
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original masks = 0.061
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harmonized masks = -0.003, a 0.064 reduction in mean composite SUVr difference
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Software 1 vs Software 2
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original masks = 0.073
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harmonized masks = 0.036, a 0.047 reduction in mean composite SUVr difference
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Validation data
Reliability
Kappa scores around binary threshold classification
Software package pair | Cohen’s Kappa |
---|---|
1 vs 2 | 1 |
1 vs 3 | 0.92 |
1 vs 4 | 0.97 |
2 vs 3 | 0.92 |
2 vs 4 | 0.97 |
3 vs 4 | 0.90 |
Agreement
Discordant patient | Composite SUVr | |||
---|---|---|---|---|
Software 1 | Software 2 | Software 3 | Software 4 | |
#1 | 0.61 | 0.61 | 0.57 | 0.61 |
#2 | 0.51 | 0.48 | 0.65 | 0.46 |
#3 | 0.62 | 0.62 | 0.61 | 0.58 |
#4 | 0.52 | 0.51 | 0.64 | 0.51 |