The trouble with quality filtering based on relative Cramér-Rao lower bounds.

Kreis, Roland (2015). The trouble with quality filtering based on relative Cramér-Rao lower bounds. Magnetic resonance in medicine, 75(1), pp. 15-18. Wiley-Liss 10.1002/mrm.25568

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Cramér Rao Lower Bounds (CRLB) have become the standard for expression of uncertainties in quantitative MR spectroscopy. If properly interpreted as a lower threshold of the error associated with model fitting, and if the limits of its estimation are respected, CRLB are certainly a very valuable tool to give an idea of minimal uncertainties in magnetic resonance spectroscopy (MRS), although other sources of error may be larger. Unfortunately, it has also become standard practice to use relative CRLB expressed as a percentage of the presently estimated area or concentration value as unsupervised exclusion criterion for bad quality spectra. It is shown that such quality filtering with widely used threshold levels of 20% to 50% CRLB readily causes bias in the estimated mean concentrations of cohort data, leading to wrong or missed statistical findings-and if applied rigorously-to the failure of using MRS as a clinical instrument to diagnose disease characterized by low levels of metabolites. Instead, absolute CRLB in comparison to those of the normal group or CRLB in relation to normal metabolite levels may be more useful as quality criteria. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

Item Type:

Journal Article (Review Article)


04 Faculty of Medicine > Department of Radiology, Neuroradiology and Nuclear Medicine (DRNN) > Institute of Diagnostic, Interventional and Paediatric Radiology > DCR Magnetic Resonance Spectroscopy and Methodology (AMSM)

UniBE Contributor:

Kreis, Roland








Christoph Hans Boesch

Date Deposited:

08 Apr 2015 16:37

Last Modified:

07 Nov 2016 15:35

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PubMed ID:


Uncontrolled Keywords:

Cramér Rao minimum variance bounds, MR spectroscopy, errors, quality control, quality filtering




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