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The absolute signal-to-noise ratio in MRI acceptance testing

1996; Wiley; Volume: 69; Issue: 827 Linguagem: Inglês

10.1259/0007-1285-69-827-1045

1748-880X

Donald W. McRobbie,

Cardiac Imaging and Diagnostics

Abstract The absolute signal-to-noise ratio (SNR) measurable from images is defined and related to the theoretical fundamental SNR for MRI. Absolute SNR for quadrature head coils was obtained by both measurement and analysis of published data for MRI systems in the range 0.5–1.5 T. Mean absolute SNR for 22 MRI systems was 1.59±0.25 × 104 Hz½ ml−1 T−1 and did not vary significantly with the static field strength or gradient strength and signal bandwidth. This can be related to the fundamental SNR calculated as 2.36 × 104 Hz½ ml−1 T−1 through an effective noise figure with an average value of 3.4 dB for the 22 systems. Use of this methodology is discussed in relation to acceptance testing and performance assessment.