Cluster analysis as a function of the number of clusters.

<p>Results from cluster analysis (cluster centres and voxel counts) as a function of k (number of clusters), and percentage reduction after induction chemotherapy (IC) for the combination of primary tumours and lymph nodes. In total, 2179 voxels were considered in the analysis, from which 1435 were measured at baseline and 744 post-IC, with a global percentage reduction of 48%. Asterisks indicate significant two-tailed p-values (p < 0.05) from the Wilcoxon signed-ranks test, comparing the number of voxels pre and post-treatment. IAUGC60 (initial area under the gadolinium curve integrated over 60 s) is expressed in units of mmol·s, ADC (apparent diffusion coefficient) in units of ×10⁻³ mm²/s.</p><p>Cluster analysis as a function of the number of clusters.