Figure 1
From: Myocardial T2* mapping: influence of noise on accuracy and precision
Plot of SNR vs. Signal intensity for different numbers of coils for root sum of squares combining. As we increase the number of coil elements, the noise bias (which is the signal at an SNR = 0) increases. Cardiac surface coil arrays can have up to 32-elements, however, the use of adaptive coil combining reduces the effective number of coils to one (see arrow) thereby reducing the noise bias.