Dynamic Cerebral Contrast-enhanced Perfusion MRI - Biomedical Signal Analysis: Contemporary Methods and Applications - page 315

1 2 3 4

rCBF: 0.04
rCBV: 0.68
MTT : 18.44

rCBF: 0.01
rCBV: 0.13
MTT : 18.54

rCBF: 0.05
rCBV: 1.00
MTT : 21.15

rCBF: 0.03
rCBV: 0.52
MTT : 16.73

5 6 7 8 rCBF: 0.01

rCBV: 0.22
MTT : 19.25

rCBF: 0.01
rCBV: 0.14
MTT : 16.72

rCBF: 0.01
rCBV: 0.11
MTT : 20.03

rCBF: 0.02
rCBV: 0.50
MTT : 20.26

9 10 11 12

rCBF: 0.01
rCBV: 0.11
MTT : 19.13

rCBF: 0.02
rCBV: 0.42
MTT : 19.69

rCBF: 0.01
rCBV: 0.22
MTT : 17.66

rCBF: 0.01
rCBV: 0.21
MTT : 20.84

13 14 15 16 rCBF: 0.00

rCBV: 0.08
MTT : 16.90

rCBF: 0.01
rCBV: 0.12
MTT : 20.44

rCBF: 0.02
rCBV: 0.34
MTT : 18.74

rCBF: 0.02
rCBV: 0.33
MTT : 17.78

Figure 11.9
Cluster-specific concentration-time curves for the “neural gas” network of a
dynamic perfusion MRI study in a control subject without evidence of
cerebrovascular disease. Cluster numbers correspond to figure 11.8. The X-axis is
the scan number, and the Y-axis is arbitrary.

data set #1, representing the minimal rCBV obtained by the minimal
free energy VQ, and the values of the three cluster validity indices de-
pending on cluster number. The cluster-dependent curve for the rCBVs
was determined based on the minimal obtained rCBV value as a re-
sult of the clustering technique for fixed cluster numbers. For each of
the twenty runs of the partitioning algorithms, the minimal codebook-
specific rCBV was computed separately. The cluster whose CTC showed
the minimal rCBV was selected for the plot. The MTT of this CTC is