Pulsed Doppler sonographic determination of normal values of blood flow velocities in the anterior cerebral artery in premature and newborn infants

In 384 healthy prematurely born infants, full-term newborns and older infants (conceptional age: 26 to 60 weeks; weight at investigation: 720 g to 5800 g) the flow in the anterior cerebral arteries was measured by pulsed doppler-sonography. All infants were investigated with a 5 MHz probe (ATL Mark 600 and Acuson 128). The following parameters were measured from the flow profile: The maximal systolic velocity, the end-systolic and end-diastolic velocity as well as the mean flow velocity, the pulsatility-index and the resistance-index. For all parameters the relationship to the conceptional age and weight were analysed. All flow velocities increased with increasing conceptional age: There was an exponential increase of the flow velocities with the conceptional age, whereas the relationship between the weight and the flow velocities was linear. In contrast to this neither the pulsatility-index nor the resistance-index changed with increasing conceptional age and weight. As flow velocities in the anterior cerebral arteries increase with increasing conceptional age and weight both parameters must be taken into consideration when pathologic flow velocities are measured.     

Doppler sonographic flow measurement in the anterior cerebral artery and celiac trunk in infants with coarctation syndrome in comparison with healthy infants

15 infants (gestational age 47 +/- 11 weeks; weight 3180 +/- 1082 g) with angiocardiographically proven coarctation of the aorta and 53 healthy infants (gestational age 39 +/- 8 weeks; weight 2830 +/- 1418 g) were investigated by echocardiography and pulsed doppler sonography. In all children pulsed doppler recordings were obtained in the anterior cerebral artery (prestenotic reference vessel) and the truncus coeliacus (poststenotic reference vessel). Nine variables were measured from each doppler signal: The maximal systolic velocity, the endsystolic and enddiastolic velocity, the pulsatility-index, the acceleration slope (peak rate of acceleration), the deceleration slope (peak rate of deceleration), the antegrade flow time and the acceleration and deceleration time. The healthy infants showed a pulsatile flow profile in the anterior cerebral artery and the truncus coeliacus. In normal subjects the maximal systolic velocity and the acceleration slope in the truncus coeliacus were always higher than in the anterior cerebral artery. There was no difference in the endsystolic and enddiastolic velocity, the pulsatility-index, the flow times and the deceleration slope. In children with coarctation of the aorta a decreased and nonpulsatile flow in the truncus coeliacus could be shown. The following variables were significantly lower than in the healthy control group: The maximal systolic velocity, the pulsatility-index, the acceleration and deceleration slope and the antegrade flow time and acceleration time. In the anterior cerebral arteries of children with coarctation the maximal systolic and enddiastolic velocity were significantly higher than in the healthy control group. Pulsed doppler recordings were obtained in 9 patients after surgical correction: The maximal systolic and endsystolic velocity, the pulsatility-index, the acceleration and deceleration slope in the truncus coeliacus increased significantly although these values were lower than in the healthy control group. The flow parameters in the anterior cerebral arteries postoperatively showed no significant difference from the preoperative values. Pulsed dopplersonography of the flow in the anterior cerebral artery and the truncus coeliacus is a good method for diagnosis of coarctation of the aorta and postoperative controls.     

Doppler sonographic flow parameter of the anterior cerebral artery in patent ductus arteriosus of the newborn infant compared to a healthy control sample

33 premature infants (age: 32 +/- 3 weeks; birth weight 1,268 +/- 535 gs) with the clinical signs of patent ductus arteriosus Botalli (PDA) and a control group of 96 healthy infants (age: 37 +/- 4 weeks; birth weight 2 348 +/- 944 gs) were investigated. Pulsed doppler recordings were obtained in the anterior cerebral arteries (ACA) and compared with the flow pattern in the truncus coeliacus (TC). In all children the maximal systolic velocity (Vs), the endsystolic (Ves) and the enddiastolic velocity (Ved) and the pulsatility-index (PI) were measured. The 96 healthy premature born infants showed the following velocities: Vs: 41 +/- 12 cm X sec-1; Ves: 19 +/- 7 cm X sec-1; Ved: 10 +/- 4 cm X sec-1. The pulsatility-index was 0.74 +/- 0.08. In children with PDA all velocities were significantly lower than in the healthy control group: Vs: 31 +/- 10 cm X sec-1; Ves: 7 +/- 6 cm X sec-1; Ved: -1 +/- 5 cm X sec-1. Ved was more decreased than Vs resulting in a significant increase in PI (1.04 +/- 0.14). 22 infants with surgically proven large PDA (age: 31 +/- 3 weeks; birth weight: 1,160 +/- 467 gs) showed significant lower velocities (Vs: 34 +/- 8 cm X sec-1; Ves: 4 +/- 4 cm X sec-1; Ved: -4 +/- 4 cm X sec-1) in comparison with the healthy control group and the 11 children with small PDA (age: 33 +/- 4 weeks; birth weight: 1,494 +/- 621 gs).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulsed Doppler sonographic measurement of normal values for the flow velocities in the intracranial arteries of healthy newborns

121 healthy premature born infants and full term newborns (corrected gestational age 29 to 45 weeks, weight at investigation 1070 to 3750 g) were investigated by pulsed Doppler sonography with a 5 MHz transducer. In all infants pulsed Doppler recordings were obtained from the internal carotid arteries (ICA), the basilar artery (BA) and both anterior cerebral arteries (ACA). From the flow profile the maximal systolic velocity (V_s), the endsystolic velocity (V_es) and the enddiastolic velocity (V_ed), the time average velocity (TAV) and the time average maximal velocity (TAMX) as well as the resistance-index (RI) and the pulsatility-index (PI) were measured. For all parameters the relationship to the gestational age was analysed and normal values were established. There was a linear increase of all flow velocities with increasing gestational age. V_s in the ICA was about 20% higher than in the ACA and BA whereas V_es and V_ed were not significantly different in the three arteries. The TAV in the ICA was 9% higher than in the ACA and 15% higher than in the BA. The TAMX in the ICA was 10% higher than in the ACA and 14% higher than in the BA. In contrast to the increase of the flow velocities neither the RI nor the PI showed a significant age dependency. For the RI in the ICA 0.77±0.08, in the ACA 0.73±0.08 and in the BA 0.72±0.09 were measured. The PI in the ICA was 3.0±0.08, in the ACA 2.7±0.09 and in the BA 2.7±0.7. Because of the age dependency of the flow velocities in the cerebral arteries the corrected gestational age must be taken into consideration when pathologic flow velocities are analysed. Presented at the ESPR meeting in Montreux 1988. Selected for publication by an International Group of the ESPR.     

Detection of reduced flow velocities in the anterior cerebral artery in premature and newborn infants and in older infants with cerebral hemorrhages using pulsed Doppler sonography

34 infants with intracerebral haemorrhage (intraventricular haemorrhage 26; subdural haemorrhage 2; epidural haemorrhage 2; subarachnoidal haemorrhage 4) were investigated by pulsed Doppler-sonography. Absolute flow velocities were measured in the anterior cerebral arteries in infants with intracranial haemorrhage and compared with the flow velocities of a healthy control group of identical gestational age, actual age and weight. All flow velocities were significantly reduced in premature and full-term infants with intracranial haemorrhage, whereas the pulsatility-index was significantly increased. 10 infants with severe intracranial haemorrhage developed a shunt-depending posthaemorrhagic hydrocephalus. These children showed a significant reduction of all flow velocities in the anterior cerebral arteries in comparison to the healthy control group. The diastolic forward flow was more reduced than the maximal systolic velocity resulting in a significant increase of the pulsatility index. In rapidly progressive hydrocephalus, often no diastolic flow or even a retrograde diastolic flow could be found. After shunt-implantation normalisation of the flow velocities could be observed. Reduced flow velocities could be observed. Reduced flow velocities in the anterior cerebral arteries in infants with subdural, epidural and subarachnoidal haemorrhage were associated with a bad outcome: 1 infant died, 1 infant developed severe leucomalacia, and 1 infant showed atrophy of one cerebral hemisphere. Normal flow velocities in the intracranial arteries in subdural, epidural and subarachnoidal were associated with a favourable prognosis. Absent or even retrograde diastolic flow indicates a dramatic decrease of cerebral perfusion. The longer the pathologic flow patterns were demonstrable the worse was prognosis.     

Doppler sonographic detection of increased flow velocities in the celiac trunk and superior mesenteric artery in infants with necrotizing enterocolitis

Fourteen infants (gestational age 28.4±4.4 weeks; birth weight 1170±910 g) with clinical and radiological signs of necrotizing enterocolitis (NEC) were investigated by pulsed Doppler sonography. Pulsed Doppler recordings were performed in the celiac trunk and the superior mesenteric artery at an age of 15±10 days. The peak systolic, end-systolic, end-diastolic and time average velocities were measured and compared with the flow velocities of a healthy control group. Infants with NEC showed a significant increase in peak systolic and time average velocity within the celiac trunk and the superior mesenteric artery in comparison with healthy infants.     

Doppler sonographic measurement of normal values of flow velocities in the internal carotid artery of premature infants, newborn infants and infants

In 121 healthy premature born infants, full-term newborns and older infants (gestational age: 29 to 45 weeks; weight at investigation: 1070 g to 3750 g), the flow velocities in the internal carotid arteries were measured by pulsed doppler sonography. All infants were investigated by computer sonography (Acuson 128) with a 5 MHz transducer. The following parameters were measured: The maximal systolic velocity, the end-systolic and end-diastolic velocity as well as the mean flow velocities, the pulsatility-index and the resistance-index. For all parameters the relationship to the gestational age and weight were analysed. All flow velocities increased linearly with increasing gestational age and weight. In contrast to the flow velocities neither the pulsatility-index nor the resistance-index changed with increasing gestational age and weight. As flow velocities in the internal carotid arteries increase with increasing gestational age and weight these parameters must be taken into consideration when pathologic flow velocities are analysed.     

Prognostic value of Doppler ultrasound blood flow measurements in the anterior cerebral artery of premature infants

The relationships between doppler-sonographic determination of systolic, diastolic flow velocity and pulsation index in the A. cerebri anterior and developmental outcome at 12 month of age were studied by means of multivariate variance and discriminance analysis. The study involves 92 preterm infants, in whom flow measurement were performed in the first 3 days and the second week of life. The influence of additional perinatal risk factors like Apgar score, blood gas values and type of intensive care were taken in consideration: Doppler-sonographic flow parameters were found to be necessary coefficients of statistically significant discriminant functions, which differentiate between infants with normal or delayed psycho-motoric development or cerebral palsy. However, in comparison to the other risk factors their weight for differentiation is low. Parameters of immediate postnatal adaptation like apgar score and blood gas values decide quality of developmental outcome in infants with as well as without ultrasonographically proven neonatal brain damage. In infants with neonatal ventricular hemorrhages only a distinct influence of immaturity was observed additionally.     

Non invasive measurement of the cerebral blood flow in infants with hydrocephalus

The present study was undertaken to verify by a non invasive Doppler technique the effect of ventricular dilatation on cerebral blood flow in infants with hydrocephalus. The measurement of pulsatile flow in cerebral arteries is also a valuable parameter for determination of optimal timing of corrective intervention.     

Aneurysms of the distal anterior cerebral artery in infants

Cerebral aneurysms in infants are rare. Of those cases that are reported, only 7 have been identified within the anterior cerebral artery circulation. We report a case of a 7-week-old female who presented with subarachnoid hemorrhage, intracerebral hemorrhage and seizure secondary to a saccular aneurysm of the distal anterior cerebral artery. At surgery, a 1.5-cm thrombosed aneurysm was excised. Postoperatively the child has done well achieving normal milestones at the age of 1 year. We present this case plus a review of the limited number of similar cases found in the literature stressing the presenting signs and symptoms, surgical considerations and outcomes.     

Position dependent changes of cerebral blood flow velocities in premature infants

The supine or prone positioning of infants has been a cause of much controversy. Recently it has been postulated that the position dependent hypoperfusion of the brainstem represents a possible cause of sudden infant death. To demonstrate position dependency and maturational changes of cerebral perfusion in premature newborn infants we investigated cerebral blood flow velocities (CBFV) in the main supratentorial and brainstem cerebral arteries. Measurements of CBFV were done with transfontanellar colour-coded Doppler sonography in the internal carotid artery (ICA), basilar artery (BA), and vertebral artery (VA) in the prone (head centered-baseline) and supine positions (maximal rotation to both sides) in 23 premature infants aged between 3-5 days of life. We performed follow-up measurements in 17 infants 7-10 days later and in 16 infants at the corrected age of 1 month. There was no difference in mean CBFVs between the prone and supine position at the first investigation. At the third investigation, CBFVs were significantly higher in the supine compared to the prone position. The CBFVs of the ICA were higher than in the BA and VA. This difference was not influenced by the body position but increased with post-natal age more in the VA (159%) than in the BA (129%) and ICA (128%). Position dependency was not seen in the ICA perfusion. In the prone position, five infants showed an incomplete steal effect in the contralateral VA. There was no significant side difference in the CBFVs of the ICA and VA, but in the resistance indices in the VA (left > right). Conclusion: in premature newborns, position dependent changes of cerebral blood flow velocity develop with maturation and are most pronounced in the vertebrobasilar system. These changes are possibly due to compression of the vertebral artery by neck movement and suggest an individual risk of brainstem perfusion deficits that may be aggravated with age and head rotation in a prone position.     

Increased cerebral blood flow velocities in newborn infants of smoking mothers

Cerebral blood flow velocities (CBFV) were measured by the pulsed Doppler method in 41 infants of smoking mothers and in 59 apparently healthy control infants. Although gestational age, birth weight, and systolic blood pressure were lower in infants exposed to tobacco smoke prenatally, systolic (65±11 vs. 47±12 cm/s, mean ±SD;P<0.001), mean (36±6 vs. 25±6 cm/s;P<0.001), and diastolic (17±4 vs 13±4 cm/s;P<0.001) CBFVs in the anterior cerebral artery were significantly higher when compared to control infants. Similar differences were seen in the internal carotid and in the basilar arteries. Multiple regression analysis did not reveal differences other than maternal smoking to explain these observations. We conclude that prenatal tobacco smoke exposure is related to increased CBFVs in newborn infants. Further studies should determine whether this relation is not only statistical but causal and whether increased CBFVs are an indicator of prolonged effects of prenatal tobacco smoke exposure.     

Blood flow velocities in the cerebral arteries and descending aorta in small-for-dates infants

Resistive indices (RI) in the anterior cerebral artery (ACA), basilar artery (BA), middle cerebral artery (MCA) and descending aorta (DA) were obtained in 15 small-for-dates (SFD) infants who were, growth retarded because of maternal pregnancy-induced hypertension and in 20 appropriate-for-dates (AFD) infants matched for gestational age between 24 h and 48 h after birth. The RIs in the MCA, ACA and BA were significantly lower, while the RI in the DA was significantly higher, in the SFD infants than in the AFD infants. These changes in RIs in the SFD infants might be similar to the brain sparing effect as reported in growth-retarded fetuses.     

Doppler flow velocities in cerebral arteries in relation to intravenous phenobarbital in premature infants weighing between 500 and 1,500 g

In very premature ventilated infants (GA 25-30 weeks, BW 575-1420 g) values for heart frequency, mean arterial blood pressure and pCO2 were obtained, and also Doppler-sonographic measurements of the right internal carotid artery were performed to assess cerebral haemodynamics, before and 5-10 min after the intravenous injection of 20 mg/kg phenobarbitone (study I/n = 10) or 5 mg/kg phenobarbitone (study II/n = 10). There were no significant changes in any of these parameters. Therefore phenobarbitone does not have seem to have any significant effect on cerebral haemodynamics up to a dosage of 20 mg/kg, so that there is no apparent effect on the risk of cerebral haemorrhage. On the other hand this study confirms that phenobarbitone can be used in very low birth weight preterm infants with this dosage without causing any substantial haemodynamic risk.     

Pulsed Doppler ultrasound blood flow measurements in the superior mesenteric artery of the newborn

In 25 healthy newborns transcutaneous Doppler ultrasound measurements (Duplex-Scan) of flow velocities in the superior mesenteric artery were performed to define normal values and to investigate the response of intestinal blood flow to feeding. The diameter of the vessel was measured from real-time and M-mode imaging: mean value 3.2 mm. The analysis of the flow patterns before and after feeding revealed a significant change of the blood flow with increase of the peak velocity (Vp) (from 57±3.1 cm/sec to 97±11.5 cm/s) and the mean velocity (Vm) (from 22±1.6 cm/s to 41±4.1 cm/s). The pulsatility index decreased from 0.85 in the fasting baby to 0.73 45 min after feeding. The Vm was correlated with the post natal age and depended upon the quantity and quality of the meals. Neonates when fed only with tea/glucose 5% or small amounts of milk in the first 24h, showed a fasting Vm of about 17–18 cm/s. Neonates older than two days who were fed with increasing amounts of milk showed a mean pre feeding Vm of 30±3.8 cm/s.     

Significance of pCO2 for cerebral blood flow in neonatology. A Doppler sonographic study

Range-gated pulsed Doppler-ultrasonographic blood flow measurements of 3 cerebral arteries (a. cerebri anterior, a. carotis interna, a. basilaris) were performed during acute pCO2-changes in 16 neonates treated in an intensive care unit. Pulsatility index, peak systolic and end diastolic flow velocity, and mean velocity were evaluated. Mean velocity in the a. carotis interna and the a. basilaris depends on the pCO2, and increases resp. decreases by 5.6% per mm Hg of rise resp. fall of the pCO2. Assuming no pCO2-dependent diameter changes of the large cerebral arteries volume flow would increase resp. decrease by a proportional amount. When obtaining qualitative or semiquantitative informations about volume flow by Doppler-ultrasonography anatomic conditions must be considered carefully.