Article Figures & Data
Figures
- Fig 1.
Typical clinical ASL map for a normocapnic 57-year-old patient with mild age-related degenerative changes. Normal CBF is depicted throughout GM with a GM CBF mean of 62.9 mL/100 g/min. The pCO2 measured 38.8 mm Hg.
- Fig 2.
ASL CBF perfusion map in a hypocapnic 58-year-old patient suspected of having an acute infarct. No abnormality was detected on conventional imaging, but the patient had marked global hypoperfusion (mean GM CBF, 25.5 mL/100 g/min). ABG showed pCO2 of 34.4 mm Hg.
- Fig 3.
ASL CBF map performed as part of the MR imaging examination demonstrated markedly increased blood flow in all GM and white matter structures consistent with global hyperperfusion (mean GM CBF, 175.2 mL/100 g tissue/min). Chest radiograph from the same date was significant for emphysema, and ABG analysis revealed a pCO2 of 56.3 mm Hg (normal range, 35–45 mm Hg).
- Fig 4.
Graph demonstrates global rates of CBF (mL/100 g/min) in GM, expressed as mean ± SD, for 3 groups (hypercapnia, normocapnia, and hypocapnia) on the basis of ABG measures of pCO2. The asterisk (*) indicates a statistically significant difference from the normocapnia group. The cross (†) indicates a statistically significant difference between the hypercapnia and hypocapnia groups. Global rates of CBF are 106.1% higher in the hypercapnia group and 38.6% lower in the hypocapnia group compared with normocapnic control subjects.
- Fig 5.
Graph of percent change versus pCO2 for all groups shows a strong linear relationship between global GM CBF and pCO2 with slight differences between male (red) and female (blue) patients.
Tables
Hypercapnia Normocapnia Hypocapnia Age (y) 57.1 ± 22.8 49.9 ± 17.3 59.8 ± 14.4 Sex (n) Male 7 10 9 Female 9 4 6 ABG latency 13.5 ± 11.3 9.7 ± 7.0 10.4 ± 7.0 HCT 29.3 ± 2.7* 34.2 ± 5.2 32.4 ± 5.9 ABG values between groups pCO2 54.4 ± 8.4*† 39.8 ± 3.3 31.6 ± 2.6*† O2 101.5 ± 70.7 95.0 ± 38.1 91.9 ± 24.5 HCO3 28.4 ± 3.9*† 24.1 ± 3.3 23.2 ± 2.4† pH 7.34 ± .06*† 7.40 ± .05 7.48 ± .04*† Note:—ABG indicates arterial blood gas; HCT, hematocrit; pCO2, partial pressure of carbon dioxide; O2, oxygen saturation; HCO3, bicarbonate. All units are expressed as mean ± SD. Units of measurement are hours for ABG latency, % blood volume for HCT, mm Hg for pCO2, % saturation for O2, and mmol/L for HCO3.
* Indicates statistically significant difference from normocapnia group.
† Indicates statistically significant difference between hypercapnia and hypocapnia groups.
Patient Sex Age pCO2 pH O2 HCO3 HCT Hours from MR GM Mean Hypercapnia 1 F 60 76.6 7.30 122.5 37.2 26.0 5.5 168.4 2 M 66 64.4 7.25 71.0 27.3 30.0 2 220.0 3 M 77 60.0 7.26 33.0 25.8 30.6 8 93.0 4 M 56 57.3 7.37 74.4 32.8 28.0 26 184.1 5 F 64 56.3 7.36 70.6 31.4 30.3 36 175.3 6 F 65 55.5 7.24 241.5 23.1 30.9 8 109.6 7 F 59 52.9 7.40 73.8 32.6 28.8 12 133.3 8 F 2 50.7 7.32 45.0 26.6 32.7 18 83.3 9 M 3 50.6 7.32 50.2 26.6 29.3 12 125.7 10 F 62 50.0 7.40 102.6 30.4 31.6 15 149.0 11 M 72 49.4 7.28 64.0 23.1 33.1 7 172.0 12 F 70 47.3 7.30 83.5 23.1 29.3 6 141.0 13 M 46 46.4 7.43 297.0 30.2 30.7 7 116.0 14 F 74 45.4 7.38 80.8 26.6 28.7 2 97.0 15 F 62 62.3 7.28 124.9 28.9 23.5 40 199.9 16 M 76 45.2 7.43 89.2 29.4 24.8 12 117.0 Hypercapnia average 57.1 54.4 7.33 101.5 28.4 29.3 13.5 142.8 Normocapnia 1 F 60 44.8 7.47 98.2 32.2 34.9 17 86.4 2 M 21 43.7 7.39 102 26.4 41 8 63.7 3 F 49 43.0 7.28 36.4 19.8 34.5 1 107.3 4 F 65 42.8 7.33 110.8 22.1 31.1 10 57.0 5 M 31 42.7 7.43 58.9 28 29.9 9 52.3 6 M 34 41.0 7.35 113 22.1 31.6 3 78.5 7 M 54 40.9 7.36 72.6 23 34.5 20 106.3 8 M 57 38.8 7.41 75.3 24.5 37.4 4 62.9 9 M 37 37.8 7.46 80.7 26.3 40.2 10 79.9 10 F 40 37.4 7.42 128.1 23.8 29 11 87.1 11 M 59 37.3 7.40 80.2 22.7 28.1 13 65.4 12 M 72 36.4 7.39 84.8 21.5 40.5 0.5 36.3 13 M 82 35.4 7.37 90.1 20.3 25.3 24 59.0 14 M 37 35.1 7.47 199.5 25 41 5 27.9 Normocapnia average 49.9 39.8 7.40 95.0 24.1 34.2 9.7 69.3 Hypocapnia 1 F 61 34.5 7.46 53.6 23.8 37.4 15 25.7 2 F 58 34.4 7.45 100 23.6 35.3 22 25.6 3 M 85 33.7 7.45 96.2 23.2 25.5 1.5 71.5 4 M 57 33.6 7.43 86.6 22.2 38.6 18 76.1 5 M 40 33.2 7.52 84.3 26.9 35.3 12.5 33.0 6 M 76 32.9 7.45 88.7 22.4 40.9 3 49.0 7 M 56 32.5 7.43 131.6 20.9 27.7 6 49.8 8 M 56 32.4 7.46 63.3 22.5 33.5 4 47.3 9 F 65 32.2 7.50 70.6 24.7 35.4 19 44.5 10 M 25 31.8 7.52 64.2 25.9 32.9 17 60.4 11 M 71 30.6 7.45 88.4 21.1 32.4 16 42.2 12 F 57 29.5 7.56 98.1 26.6 21.4 6 30.0 13 F 71 28.6 7.56 129.6 25.1 38.5 2 23.1 14 M 65 28.4 7.50 132.8 21.7 24.6 9 24.4 15 F 54 25.1 7.47 90.1 17.9 26.9 5 35.0 Hypocapnia average 59.8 31.6 7.48 91.9 23.2 32.4 10.4 42.5 Note:—GM indicates gray matter.
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