Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign

Schmidt M, Engelhorn T, Marxreiter F, Winkler J, Lang S, Kloska S, Gölitz P, Dörfler A (2017)

Publication Type: Journal article

Publication year: 2017

Journal

BMC Neurology BMC

Book Volume: 17

Journal Issue: 1

DOI: 10.1186/s12883-017-0975-2

Abstract

BACKGROUND: The loss of the swallow-tail sign of the substantia nigra has been proposed for diagnosis of Parkinson's disease. Aim was to evaluate, if the sign occurs consistently in healthy subjects and if it can be reliably detected with high-resolution 7T susceptibility weighted imaging (SWI). METHODS: Thirteen healthy adults received SWI at 7T. 3 neuroradiologists, who were blinded to patients' diagnosis, independently classified subjects regarding the swallow-tail sign to be present or absent. Accuracy, positive and negative predictive values (PPV and NPV) as well as inter- and intra-rater reliability and internal consistency were analyzed. RESULTS: The sign could be detected in 81% of the cases in consensus reading. Accuracy to detect the sign compared to the consensus was 100, 77 and 96% for the three readers with PPV reader 1/2/3 = 1/0.45/0.83 and NPV = 1/1/1. Inter-rater reliability was excellent (inter-class correlation coefficient = 0.844, alpha = 0.871). Intra-rater reliability was good to excellent (reader 1 R/L = 0.625/0.786; reader 2 = 0.7/0.64; reader 3 = 0.9/1). CONCLUSION: The swallow-tail sign can be reliably detected. However, our data suggest its occurrence is not consistent in healthy subjects. It may be possible that one reason is an individually variable molecular organization of nigrosome 1 so that it does not return a uniform signal in SWI.

Authors with CRIS profile

Manuel Schmidt Department of Neuroradiology Tobias Martin Engelhorn Department of Neuroradiology Franz Marxreiter Department of Molecular Neurology Jürgen Winkler Professur für Molekulare Neurologie Stephan Kloska Department of Neuroradiology Philipp Gölitz Medizinische Fakultät Arnd Dörfler Department of Neuroradiology

Additional Organisation(s)

Interdisziplinäres Zentrum für Klinische Forschung

How to cite

APA:

Schmidt, M., Engelhorn, T., Marxreiter, F., Winkler, J., Lang, S., Kloska, S.,... Dörfler, A. (2017). Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign. BMC Neurology, 17(1). https://doi.org/10.1186/s12883-017-0975-2

MLA:

Schmidt, Manuel, et al. "Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign." BMC Neurology 17.1 (2017).

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