Results of quantitative analysis in 34 patients who had lesions in the MCA territory (mean ± SD)
| b = 1000 (1NEX) | b = 2000 (2NEX) | |||
|---|---|---|---|---|
| Lesion | Contralateral | Lesion | Contralateral | |
| Mean Vol. (ml) | 22.1 ± 27.9 | NA | 32.5 ± 36.5* | NA |
| Signal Intensity | 440.2 ± 96.8 | 342.3 ± 62.3 | 286.4 ± 87.5* | 189.6 ± 42.5* |
| Noise | 11.6 ± 2.1 | 9.0 ± 1.9* | ||
| SNR | 38.7 ± 9.8 | 30.0 ± 6.4 | 32.3 ± 8.1* | 21.6 ± 4.8* |
| CNR | 8.7 ± 6.4 | 10.7 ± 6.5* | ||
| ADC (10−4 × mm2/s) | 6.0 ± 1.3 | 7.6 ± 1.5 | 4.6 ± 0.9* | 6.1 ± 0.7* |
Abbreviations—NEX; number of excitation, Contralateral; contralateral normal area corresponding to the ischemic lesion. Vol.; volume, NA; not available, SNR; signal to noise ratio defined as SROI/σ (SROI = signal intensity at the region of interest, σ = standard deviation of background signal intensity), CNR; contrast to noise ratio defined as the difference of SNR between the lesion and corresponding contra-lateral normal area, ADC; apparent diffusion coefficient,
* statistical difference between b = 1000 and b = 2000 images (paired samples t test, P < 0.001).