NORMAL MIDDLE CEREBRAL ARTERY

PULSATILITY INDEX (PI)  

 

GA
(wks)

Pulsatility Index

GA
(wks)

Pulsatility Index

Lower
Limit°

Predicted
Value

Upper
Limit°°

Lower
Limit°

Predicted
Value

Upper
Limit°°

15
16
17
18
19
20
21
22
23
24
25
26
27
28

0.99
1.08
1.16
1.23
1.30
1.35
1.40
1.44
1.48
1.51
1.52
1.54
1.54
1.54

1.57
1.71
1.83
1.95
2.05
2.14
2.22
2.29
2.34
2.38
2.41
2.43
2.44
2.43

2.14
2.33
2.51
2.67
2.81
2.93
3.04
3.13
3.20
3.26
3.30
3.32
3.33
3.32

29
30
31
32
33
34
35
36
37
38
39
40
41
42

1.52
1.50
1.48
1.44
1.40
1.35
1.29
1.22
1.15
1.07
0.98
0.89
0.78
0.67

2.41
2.38
2.34
2.28
2.21
2.13
2.04
1.94
1.82
1.69
1.56
1.40
1.24
1.06

3.30
3.26
3.20
3.12
3.03
2.92
2.79
2.65
2.49
2.32
2.13
1.92
1.70
1.45

GA = Gestational Age.
° = Predicted value - (2 × 0.184 × predicted value).
°° = Predicted value + (2 × 0.184 × predicted value).
 

 

 

REFERENCES

 

Mari G, Deter RL. Middle cerebral artery velocity waveforms in normal and small for gestational age fetuses. Am J Obstet Gynecol 1992;166:1262-1270.