Table 2.
Cerebral hemodynamics measurements using CDUS, MRI, and TCD.
| Young |
Middle age |
Old |
p-value |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Variables | Men | Women | Men | Women | Men | Women | Age | Sex | Age × Sex |
| Color-coded duplex ultrasonography: CDUS | |||||||||
| Total CBF (mL/min) | 633 ± 76 | 654 ± 81 | 583 ± 82 | 544 ± 85* | 533 ± 73 | 516 ± 76*† | <0.001 | 0.316 | 0.125 |
| ICA (mL/min) | 482 ± 80 | 494 ± 73 | 441 ± 72 | 406 ± 70* | 396 ± 66 | 385 ± 73*† | <0.001 | 0.301 | 0.223 |
| VA (mL/min) | 151 ± 32 | 160 ± 31 | 143 ± 39 | 137 ± 46 | 137 ± 40 | 131 ± 38* | 0.018 | 0.885 | 0.542 |
| nCBF (mL/100 g/min) | 46 ± 6 | 51 ± 6 | 43 ± 6 | 46 ± 7* | 41 ± 5 | 44 ± 6* | <0.001 | <0.001 | 0.479 |
| CVR (mmHg/mL/min) | 0.14 ± 0.02 | 0.12 ± 0.02 | 0.16 ± 0.03 | 0.17 ± 0.03* | 0.18 ± 0.03 | 0.17 ± 0.04* | <0.001 | 0.520 | 0.165 |
| nCVR (mmHg/mL/100 g/min) | 1.90 ± 0.32 | 1.57 ± 0.21 | 2.13 ± 0.36 | 1.95 ± 0.33* | 2.28 ± 0.40 | 2.02 ± 0.37* | <0.001 | <0.001 | 0.479 |
| ICA (mmHg/mL/min) | 0.18 ± 0.04 | 0.16 ± 0.03 | 0.21 ± 0.04 | 0.22 ± 0.05* | 0.24 ± 0.05 | 0.24 ± 0.06*† | <0.001 | 0.707 | 0.183 |
| VA (mmHg/mL/min) | 0.60 ± 0.17 | 0.52 ± 0.12 | 0.69 ± 0.25 | 0.74 ± 0.34* | 0.76 ± 0.30 | 0.74 ± 0.28* | <0.001 | 0.598 | 0.443 |
| Phase contrast magnetic resonance imaging: PC-MRI | |||||||||
| Total CBF (mL/min) | 603 ± 73 | 692 ± 97 | 548 ± 89 | 578 ± 112* | 513 ± 80 | 521 ± 72*† | <0.001 | 0.003 | 0.063 |
| ICA (mL/min) | 461 ± 67 | 513 ± 74 | 411 ± 71 | 440 ± 82* | 389 ± 73 | 400 ± 65* | <0.001 | 0.008 | 0.365 |
| VA (mL/min) | 142 ± 36 | 179 ± 37 | 137 ± 40 | 138 ± 53* | 125 ± 37 | 121 ± 39* | <0.001 | 0.080 | 0.024 |
| nCBF (mL/100 g/min) | 44 ± 5 | 54 ± 7 | 41 ± 7 | 49 ± 9* | 39 ± 6 | 45 ± 6* | <0.001 | <0.001 | 0.133 |
| Arterial spin labeling: ASL (mL/100 g/min) | |||||||||
| Cortex perfusion | 47 ± 9 | 55 ± 8 | 46 ± 8 | 49 ± 8 | 41 ± 10 | 49 ± 10* | 0.002 | <0.001 | 0.212 |
| Global brain perfusion | 43 ± 8 | 52 ± 7 | 43 ± 7 | 47 ± 8 | 39 ± 9 | 46 ± 9* | 0.003 | <0.001 | 0.242 |
| Transcranial Doppler: TCD | |||||||||
| CBF velocity (cm/s) | 55 ± 6.2 | 62 ± 6.3 | 52 ± 7.4 | 57 ± 9.0* | 46 ± 8.5 | 51 ± 8.7*† | <0.001 | <0.001 | 0.692 |
| CVRi (mmHg/cm/s) | 1.59 ± 0.26 | 1.29 ± 0.16 | 1.78 ± 0.34 | 1.57 ± 0.32* | 2.07 ± 0.39 | 1.74 ± 0.32*† | <0.001 | <0.001 | 0.516 |
| PI (a.u) | 0.79 ± 010 | 0.80 ± 0.12 | 0.87 ± 0.12 | 0.90 ± 0.09* | 1.00 ± 0.10 | 1.03 ± 0.11*† | <0.001 | 0.241 | 0.786 |
| EtCO2 (mmHg) | 39 ± 3 | 38 ± 4 | 39 ± 3 | 38 ± 3 | 36 ± 4 | 37 ± 5* | 0.007 | 0.367 | 0.677 |
CBF: cerebral blood flow; ICA: internal carotid artery; VA: vertebral artery; nCBF: normalized total CBF by total brain mass. CVR: cerebrovascular resistance; nCVR, normalized CVR. GM: gray matter; WM: white matter; CVRi: CVR index; PI: pulsatility index; EtCO2: end-tidal CO2. Data are mean ± standard deviation. Bold values represent p < 0.05. Results from one-way analysis of variance p < 0.05 * vs young; p < 0.05 † vs. middle age. p < 0.05 * vs young; p < 0.05 † vs. middle age. Global brain perfusion was calculated by gray and white matter perfusion. No calculation of CVR for PC-MRI and ASL due to no blood pressure assessment on the visit or during MRI.