Session Information
Date: Wednesday, June 22, 2016
Session Title: Parkinson's disease: Neuroimaging and neurophysiology
Session Time: 12:00pm-1:30pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To investigate the differences between visual and automated analyses of brain dopamine transporter (DAT) SPECT scans.
Background: Clinical evaluation of DAT SPECT scans typically relies on visual evaluation of striatal tracer binding in combination with an automated semiquantitative region-of-interest (ROI) –based method. The interpretation of the result is complicated in cases that show disagreement between the two methods on the borderline of abnormality. The prevalence and clinical characteristics of these cases are unknown.
Methods: Automated ROI analyses (BRASS software) and independent visual evaluations by two experienced nuclear medicine physicians, blinded to automated ratings, were performed for 120 parkinsonism patients scanned with [123I]FP-CIT SPECT. The scans were selected to represent the large range of tracer binding and they were evenly distributed across ages and genders. Agreement between visual and automated analyses was investigated with Cohen’s kappa. Cases with discrepant results were identified and the clinical characteristics of these patients were studied in detail.
Results: Inter-rater agreement between the visual evaluations was excellent (κ=0.81) and the agreement between visual and automated analyses was good (κ=0.66 and κ=0.72). However, twelve patients (10%) showed discrepancy between the two methods. Nine were visually evaluated as abnormal while automated analysis categorized them as normal, and vice versa in three cases. Patients with discrepant findings had 17.6% lower mean striatal tracer binding compared to normal scans (p=0.003) and 62.7% higher binding compared to abnormal scans (p<0.0001). These patients were older compared to patients with non-discrepant normal findings (72.6 vs. 62.4 years, p=0.023) and after a clinical follow-up of 4.5 years, none of them developed neurodegenerative dopaminergic parkinsonism (one case was lost to follow-up).
Conclusions: Clinical DAT SPECT scans show discrepancy between visual and automated analyses in 10% of cases. The disagreement is mostly due to visual evaluations interpreted as abnormal without tracer binding reductions in the ROI analysis. The majority of the patients with discrepant analyses are older patients. Importantly, patients with discrepant imaging findings do not seem to develop degenerative parkinsonism syndromes.
| Discrepancy | No. | Age | Sex | Clinical reason for imaging | Symptom duration and predominant side of motor symptoms | Current diagnosis | Cognitive defect |
| Brass normal, visual abnormal | 1 | 59 | M | Suspected parkinsonism plus sdr | 2 years, Left side | Alzheimer’s disease | Yes |
| 2 | 70 | F | Re-evaluation of PD diagnosis | 11 years, Right side | Undetermined parkinsonism | No | |
| 3 | 73 | F | Differential diagnosis between PD and DIP | 0.5 years, Right side | DIP (Risperidone 2 mg/day) | Yes | |
| 4 | 80 | F | Differential diagnosis between PD and DIP | 5 years, Right side | DIP (Prochlorperazine, dose unknown) | Yes | |
| 5 | 84 | F | Suspected PD | 0.5 years, Right side | DIP (Perfenazine 8 mg/day) | Yes | |
| 6 | 82 | F | Differential diagnosis between PD and DIP | 1.5 years, Symmetrical | DIP (Risperidone, dose unknown) | Yes | |
| 7 | 74 | M | Unclear Parkinsonian sdr | 5 years, Symmetrical | Essential tremor | No | |
| 8 | 76 | F | Re-evaluation of PD diagnosis | 5 years, Symmetrical | Unknown | No | |
| 9 | 80 | M | Unclear Parkinsonian sdr | 1 year, Right side | Vascular parkinsonism | Yes | |
| Brass abnormal, visual normal | 10 | 60 | M | Unclear Parkinsonian sdr | 1 year, Symmetrical | Cervical degenerative disease | No |
| 11 | 64 | M | Unclear Parkinsonian sdr | 30 years, Right side | Essential tremor | No | |
| 12 | 69 | M | Differential diagnosis between PD and ET | 10 years, Right side | Essential tremor | No |
To cite this abstract in AMA style:
E. Mäkinen, J. Joutsa, J. Johansson, M. Mäki, M. Seppänen, V. Kaasinen. Visual vs. automated analysis of [123I]FP-CIT SPECT scans in patients with parkinsonism [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/visual-vs-automated-analysis-of-123ifp-cit-spect-scans-in-patients-with-parkinsonism/. Accessed June 15, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/visual-vs-automated-analysis-of-123ifp-cit-spect-scans-in-patients-with-parkinsonism/