TY  - JOUR
A1  - Brumberg, Joachim
A1  - Schröter, Nils
A1  - Blazhenets, Ganna
A1  - Frings, Lars
A1  - Volkmann, Jens
A1  - Lapa, Constantin
A1  - Jost, Wolfgang H.
A1  - Isaias, Ioannis U.
A1  - Meyer, Philipp T.
T1  - Differential diagnosis of parkinsonism: a head-to-head comparison of FDG PET and MIBG scintigraphy
JF  - NPJ Parkinsons Disease
N2  - [\(^{18}\)F]fluorodeoxyglucose (FDG) PET and [\(^{123}\)I]metaiodobenzylguanidine (MIBG) scintigraphy may contribute to the differential diagnosis of neurodegenerative parkinsonism. To identify the superior method, we retrospectively evaluated 54 patients with suspected neurodegenerative parkinsonism, who were referred for FDG PET and MIBG scintigraphy. Two investigators visually assessed FDG PET scans using an ordinal 6-step score for disease-specific patterns of Lewy body diseases (LBD) or atypical parkinsonism (APS) and assigned the latter to the subgroups multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome. Regions-of-interest analysis on anterior planar MIBG images served to calculate the heart-to-mediastinum ratio. Movement disorder specialists blinded to imaging results established clinical follow-up diagnosis by means of guideline-derived case vignettes. Clinical follow-up (1.7 +/- 2.3 years) revealed the following diagnoses: n = 19 LBD (n = 17 Parkinson's disease [PD], n = 1 PD dementia, and n = 1 dementia with Lewy bodies), n = 31 APS (n = 28 MSA, n = 3 PSP), n = 3 non-neurodegenerative parkinsonism; n = 1 patient could not be diagnosed and was excluded. Receiver operating characteristic analyses for discriminating LBD vs. non-LBD revealed a larger area under the curve for FDG PET than for MIBG scintigraphy at statistical trend level for consensus rating (0.82 vs. 0.69, p = 0.06; significant for investigator #1: 0.83 vs. 0.69, p = 0.04). The analysis of PD vs. MSA showed a similar difference (0.82 vs. 0.69, p = 0.11; rater #1: 0.83 vs. 0.69, p = 0.07). Albeit the notable differences in diagnostic performance did not attain statistical significance, the authors consider this finding clinically relevant and suggest that FDG PET, which also allows for subgrouping of APS, should be preferred.
KW  - clinical diagnosis
KW  - F-18-FDG PET
KW  - disease
KW  - dementia
KW  - accuracy
KW  - stimulation
KW  - guidelines
KW  - criteria
KW  - brain
KW  - risk
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230675
VL  - 6
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Blazhenets, Ganna
A1  - Schröter, Nils
A1  - Frings, Lars
A1  - Jost, Wolfgang H.
A1  - Lapa, Constantin
A1  - Meyer, Philipp T.
T1  - Imaging cardiac sympathetic innervation with MIBG: linear conversion of the heart-to-mediastinum ratio between different collimators
JF  - EJNMMI Physics
N2  - Background
The heart-to-mediastinum (H/M) ratio is a commonly used parameter to measure cardiac I-123 metaiodobenzylguanidine (MIBG) uptake. Since the H/M ratio is substantially influenced by the collimator type, we investigated whether an empirical linear conversion of H/M ratios between camera systems with low-energy (LE) and medium-energy (ME) collimator is possible.

Methods
We included 18 patients with parkinsonism who were referred to one of the two participating molecular imaging facilities for the evaluation of cardiac sympathetic innervation by MIBG scintigraphy. Two consecutive planar image datasets were acquired with LE and ME collimators at 4 h after MIBG administration. Linear regression analyses were performed to describe the association between the H/M ratios gained with both collimator settings, and the accuracy of a linear transfer of the H/M ratio between collimators and across centers was assessed using a leave-one-out procedure.

Results
H/M ratios acquired with LE and ME collimators showed a strong linear relationship both within each imaging facility (R\(^2\) = 0.99, p < 0.001 and R\(^2\) = 0.90, p < 0.001) and across centers (H/M-LE = 0.41 × H/M-ME + 0.63, R\(^2\) = 0.97, p < 0.001). A linear conversion of H/M ratios between collimators and across centers was estimated to be very accurate (mean absolute error 0.05 ± 0.04; mean relative absolute error 3.2 ± 2.6%).

Conclusions
The present study demonstrates that a simple linear conversion of H/M ratios acquired with different collimators is possible with high accuracy. This should greatly facilitate the exchange of normative data between settings and pooling of data from different institutions.
KW  - MIBG
KW  - collimator
KW  - heart-to-mediastinum ratio
KW  - linear conversion
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-221675
VL  - 6
ER  -