Fetal Intraventricular Hemorrhage Due to Antiphospholipid Syndrome: A Case Report.

Obstetric Antiphospholipid Syndrome (OAPS) is an autoimmune disease characterized by certain pregnancy complications in association with persistent antiphospholipid antibodies. These antibodies are generally known for their prothrombotic characteristics and may affect mother and fetus during the entire pregnancy. The clinical criteria for OAPS, including recurrent fetal loss, intra-uterine growth restriction and premature birth due to severe preeclampsia, all suggest uteroplacental vascular insufficiency. Although rare, thrombotic complications have been described in neonates born to mothers with OAPS, mainly ischemic stroke. We report on the first case of extensive fetal intraventricular hemorrhage related to OAPS. We share our diagnostic search and analysis for this unusual antenatal event, including cranial ultrasound findings and postmortem MRI images. We will also present a short review of the etiology and prognosis of antenatal intraventricular hemorrhage. We suggest that women with severe or early preeclampsia and/or a history of pregnancy loss should be evaluated for OAPS and carefully monitored throughout pregnancy. Further, we advise to test mothers for OAPS in the case of idiopathic fetal hemorrhage.

The CHOPIn Study: a Multicenter Study on Cerebellar Hemorrhage and Outcome in Preterm Infants.

Cerebellar hemorrhage (CBH) is a frequent complication of preterm birth and may play an important and under-recognized role in neurodevelopment outcome. Association between CBH size, location, and neurodevelopment is still unknown. The main objective of this study was to investigate neurodevelopmental outcome at 2 years of age in a large number of infants with different patterns of CBH. Of preterm infants (≤ 34 weeks) with known CBH, perinatal factors, neuro-imaging findings, and follow-up at 2 years of age were retrospectively collected. MRI scans were reassessed to determine the exact size, number, and location of CBH. CBH was divided into three groups: punctate (≤ 4 mm), limited (> 4 mm but < 1/3 of the cerebellar hemisphere), or massive (≥ 1/3 of the cerebellar hemisphere). Associations between pattern of CBH, perinatal factors, and (composite) neurodevelopmental outcome were assessed. Data of 218 preterm infants with CBH were analyzed. Of 177 infants, the composite outcome score could be obtained. Forty-eight out of 119 infants (40%) with punctate CBH, 18 out of 35 infants (51%) with limited CBH, and 18 out of 23 infants (78%) with massive CBH had an abnormal composite outcome score. No significant differences were found for the composite outcome between punctate and limited CBH (P = 0.42). The risk of an abnormal outcome increased with increasing size of CBH. Infants with limited CBH have a more favorable outcome than infants with massive CBH. It is therefore important to distinguish between limited and massive CBH.

Symmetrical Thalamic Lesions in the Newborn: A Case Series.

Although bilateral injury to the thalami is often seen in (near)term infants with hypoxic ischemic encephalopathy (HIE), symmetrical thalamic lesions (STL) is a different, very rare condition, seen both in full-term and preterm infants often after an antenatal insult, although the history is not always clear. These lesions are usually first detected using cranial ultrasound (cUS). They may not always be seen on the first (admission) scan, but become apparent in the course of the 1st week after birth. Clinically, these infants present with hypo- or hypertonia, absence of sucking and swallowing reflexes, and they may have contractures and facial diplegia. Neuropathology commonly demonstrates a thalamic lesion with additional and variable involvement of basal ganglia and brainstem. The prognosis is very poor, the condition often leads to severe disabilities and/or death within the first years of life. The clinical course and neuroimaging findings of 13 patients with symmetrical thalamic lesions (STL) are reported.

Cranial ultrasonography of the immature cerebellum: Role and limitations.

Cranial ultrasonography (CUS) is a reliable and non-invasive tool to detect frequently occurring brain abnormalities and to monitor brain development and maturation in high risk neonates. Standard CUS views are obtained through the anterior fontanel. However, evaluation of the posterior fossa is often suboptimal with this approach. Cerebellar injury occurs frequently in preterm infants and has important prognostic consequences. Early detection is therefore important. This review focuses on techniques that optimize the performance of CUS when studying the preterm cerebellum, including the use of the mastoid fontanel and the adaptation of focus points and scan frequencies. For illustration, CUS images of the normal posterior fossa anatomy as well as examples of abnormalities that may be encountered in preterm infants are included. We also discuss the limitations of CUS and the role of magnetic resonance imaging.

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI.

OBJECTIVES: We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard. METHODS: In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated. RESULTS: Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16% and 99%. Adding MF views increased the sensitivity of US to 82%. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57% and 95%. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS. CONCLUSIONS: PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates. KEY POINTS: • Posterior fossa abnormalities are a frequent finding in high-risk term infants. • Adding mastoid fontanelle views improves ultrasound detection of clinically relevant abnormalities. • Hypoxic-ischemic injury and small posterior fossa haemorrhages are better detected with MRI. • Cranial ultrasound examination should include mastoid fontanelle views in high-risk term neonates.

Echogenicity changes in the fetal brain, a 6-year follow-up study.

OBJECTIVE: To asses the relation between echogenicity changes in the fetal brain and neurodevelopmental outcome until 6 years of age. METHODS: Fetuses (n = 124) from pregnancies affected by hypertensive disorders (n = 64) or preterm labor (n = 60) at risk for preterm birth (26-34 weeks gestation) were studied. Moderate echogenicity changes (periventricular grade IB, II; intraventricular grade II-III; local basal ganglia/thalami) in the fetal and neonatal brain were related to neurological outcome and Griffiths mental developmental scales quotients at 1, 2 and 6 years. Multiple regression analysis tested the influence of moderate echogenicity changes and perinatal clinical characteristics on composite outcome (death or abnormal neurodevelopment). RESULTS: Moderate echogenicity changes were present in 37/124 (30%) fetuses. Median gestational age and weight at birth were respectively 31 weeks (range 26-43), 1314 g (range 550-4330), mortality was 19%, follow-up loss 10%. Composite outcome was abnormal in 47/124 (38%). Fetal and neonatal moderate intraventricular echodensities were related to cerebral palsy at 6 years (p < 0.04). In the multiple regression analysis only gestational age was related to composite outcome (p = 0.005). CONCLUSIONS: Moderate intraventricular echodensities in the fetal brain related to cerebral palsy at 6 years of age. Gestational age at birth was the main predictor of abnormal composite outcome.

Placental histology related to fetal brain sonography.

BACKGROUND: Chronic hypoxia and inflammatory processes can induce placental disturbances that may indirectly lead to perinatal brain injury. OBJECTIVE: To study histological features of the placenta in relation to echogenicity changes in the periventricular white matter, ventricular system and basal ganglia/thalami of the fetal brain. DESIGN: Prospective study of 77 fetuses between 26 and 34 weeks gestational age with their placentas. The pregnancies were complicated by hypertensive disorders (n=42) or preterm labour (n=35). RESULTS: Of the placentas 79% showed uteroplacental hypoperfusion, inflammation or a combination. Transvaginal ultrasound examination of the brain revealed echogenicity changes in 73% of the fetuses (44 mild, 29 moderate). Moderate brain echogenicity changes (periventricular echodensity (PVE) grade IB: increased echogenicity brighter than choroid plexus, intraventricular echodensity (IVE) grade II and III: echodensity filling ventricle respectively <50% and ≥50%; basal ganglia/thalamic echodensity (BGTE): locally increased echogenicity within basal ganglia/thalami) were equally distributed over cases with uteroplacental hypoperfusion and inflammatory features in the placenta. PVE grade IB was always associated with placental pathology. The sensitivity and negative predictive value of placental pathology for moderate echogenicity changes were high (0.91 and 0.88, respectively), while the specificity and positive predictive value were low (0.27 and 0.34, respectively). CONCLUSIONS: Normal placental histology predicted no or mild echogenicity changes, supporting the view that the latter are physiological. Placental pathology was always present in cases with grade IB PVE, presumed to represent mild or early forms of white matter injury. Both uteroplacental hypoperfusion and inflammatory features were seen in placentas from pregnancies with hypertensive disorders.

Fetal general movements and brain sonography in a population at risk for preterm birth.

BACKGROUND: General movements (GMs) assessed three months post term are related to brain injury and neurological outcome. AIMS: To study GMs in fetuses and their predictive value for echogenicity changes in the fetal brain. STUDY DESIGN: Prospective study of fetal GMs (classified as normal or abnormal) and echogenicity changes in the periventricular, basal ganglia/thalami area, and ventricular system (classified as absent, mild or moderate). SUBJECTS: 121 fetuses from pregnancies affected by hypertensive disorders and/or preterm labour, at risk for preterm birth (26-34weeks gestational age). OUTCOME MEASURES: Prevalence of abnormal GMs, GM parameters (amplitude, speed and complexity), and moderate echogenicity changes in the fetal brain (periventricular >or=IB, intraventricular grade II/III, and basal ganglia/thalamus locally increased). Predictive values of GMs for clinical parameters and moderate echogenicity changes. RESULTS: GMs were abnormal in 58%, with amplitude affected in 96%, and speed and complexity in 59%. Abnormal GMs correlated with oligohydramnios (p=0.002) and hypertensive disorders (p=0.015). Echogenicity changes of the brain were absent, mild and moderate in 27%, 39% and 31%, respectively. The sensitivity of GMs for moderate echogenicity changes in the three areas combined was 0.65, and the periventricular area 0.85, specificity both 0.44, negative predictive values 0.73 and 0.96 respectively. CONCLUSIONS: Qualitative abnormal GMs are frequent in fetuses of compromised pregnancies, and correlate with hypertensive disorders and oligohydramnios. The amplitude of GMs was most frequently affected. Abnormal GMs relate to moderate echogenicity changes especially in the periventricular area of the fetal brain, while normal GMs predict absence of moderate echogenicity changes.

Lenticulostriate vasculopathy in very preterm infants.

OBJECTIVE: To assess for lenticulostriate vasculopathy (LSV) on cranial ultrasound (cUS) scans of very preterm infants: incidence and aetiology, evolution during neonatal period, association with clinical parameters, and MRI equivalent. DESIGN: Prospective study. SETTING: Tertiary neonatal referral centre. PATIENTS: Very preterm infants (<32 weeks) underwent sequential cUS throughout the neonatal period and MRI around term age. cUS were evaluated for LSV and other changes, and MRI for changes in signal and myelination in deep grey matter. LSV was divided into early-onset (7 postnatal days). Perinatal clinical parameters were collected for all infants and compared between groups. RESULTS: In 22/111 (20%) infants LSV was detected: early-onset in 5 and late-onset in 17. LSV mostly presented some weeks after birth and persisted for several months. There were no associations between LSV and other changes on cUS or deep grey matter changes on MRI. Infants with late-onset LSV were younger and smaller at birth than infants with early-onset LSV. Postmenstrual age at first detection was comparable for both LSV groups. There were no associations between LSV and perinatal clinical parameters, but infants with LSV had less episodes of hypotension than infants without LSV. CONCLUSIONS: LSV is a frequent finding on cUS in very preterm infants, but does not show on MRI. The postmenstrual age, rather than gestational and postnatal age, seems important in LSV development. LSV is not associated with clinical parameters. When encountered in otherwise healthy preterm infants, LSV is probably a benign temporary phenomenon.

Do apparent diffusion coefficient measurements predict outcome in children with neonatal hypoxic-ischemic encephalopathy?

BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) permits early detection and quantification of hypoxic-ischemic (HI) brain lesions. Our aim was to assess the predictive value of DWI and apparent diffusion coefficient (ADC) measurements for outcome in children with perinatal asphyxia. MATERIALS AND METHODS: Term neonates underwent MR imaging within 10 days after birth because of asphyxia. MR imaging examinations were retrospectively evaluated for HI brain damage. ADC was measured in 30 standardized brain regions and in visibly abnormal areas on DWI. In survivors, developmental outcome until early school age was graded into the following categories: 1) normal, 2) mildly abnormal, and 3) definitely abnormal. For analysis, category 3 and death (category 4) were labeled "adverse," 1 and 2 were "favorable," and 2-3 and death were "abnormal" outcome. Differences in outcome between infants with and without DWI abnormalities were analyzed by using chi(2) tests. The nonparametric Mann-Whitney U test analyzed whether ADC values in visible DWI abnormalities correlated with age at imaging. Logistic regression analysis tested the predictive value for outcome of the ADC in each standardized brain region. Receiver operating characteristic analysis was used to find optimal ADC cutoff values for each region for the various outcome scores. RESULTS: Twenty-four infants (13 male) were included. Mean age at MR imaging was 4.3 days (range, 1-9 days). Seven infants died. There was no difference in outcome between infants with and without visible DWI abnormalities. Only ADC of the posterior limb of the internal capsule correlated with age. ADC in visibly abnormal DWI regions did not have a predictive value for outcome. Of all measurements performed, only the ADC in the normal-appearing basal ganglia and brain stem correlated significantly with outcome; low ADC values were associated with abnormal/adverse outcome, and higher ADC values, with normal/favorable outcome (basal ganglia: P = .03 for abnormal, P = .01 for adverse outcome; brain stem: P = .006 for abnormal, P = .03 for adverse outcome). CONCLUSIONS: ADC values in normal-appearing basal ganglia and brain stem correlated with outcome, independently of all MR imaging findings including those of DWI. ADC values in visibly abnormal brain tissue on DWI did not show a predictive value for outcome.

Is there a way to predict outcome in (near) term neonates with hypoxic-ischemic encephalopathy based on MR imaging?

BACKGROUND AND PURPOSE: It has previously been demonstrated that comparison of signal intensity (SI) between selected brain structures on T1-weighted images enables distinction between the absence or presence of hypoxic-ischemic (HI) brain injury in young infants. The aim of the present study was to assess whether this method of brain structure T1-weighted SI comparison also enables prediction of outcome. MATERIALS AND METHODS: Survivors of a group of 57 children with neonatal HI encephalopathy (HIE) grade 2 or 3 according to Sarnat and Sarnat and controls who underwent neonatal MR imaging were retrospectively assigned to 1 of 3 outcome groups at 5 years of age, depending on developmental outcome: 1) normal, 2) mildly abnormal, and 3) definitely abnormal. Gestational age was not significantly different between the HIE group (range, 35 + 5-42 + 5 weeks; mean, 39 + 4 weeks) and control group (range, 35 + 0-42 + 1 weeks; mean, 39 + 2 weeks). We calculated the predictive values of the neonatal clinical HIE classification according to Sarnat and Sarnat for outcome (neonatal death and developmental outcome in survivors). We assessed which brain structure T1-weighted SI comparison scored best for outcome prediction. Predictive values of that comparison for outcome were calculated for the entire group and for the HIE grade 2 group only, a patient group with highly variable outcome. RESULTS: Of the 57 children, 6 died. Outcome group 1 consisted of 31; group 2, of 14; and group 3, of 6 children. The positive predictive value of the neonatal clinical classification for adverse outcome (outcome group 3 and death) was 52%; and negative predictive value, 100%. These were respectively 45% and 0% in children with HIE grade 2. Of all brain structure T1-weighted SI comparisons, that of the posterior limb of the internal capsule versus the posterolateral putamen scored best for outcome prediction. The positive predictive value for adverse outcome was 69%; and negative predictive value, 98%. In children with HIE grade 2, the positive predictive value and negative predictive value for adverse outcome were 67% and 88%. CONCLUSIONS: Brain structure T1-weighted SI comparisons are helpful to predict outcome in (near) term neonates with HIE. This finding adds to the current knowledge and clinical practice. If the SI in the posterolateral putamen is less than the SI in the posterior limb of the internal capsule, favorable outcome is very likely, whereas if the SI in the posterolateral putamen is equal to or greater than the SI in the posterior limb of the internal capsule, adverse outcome is very likely. In neonates with HIE grade 2 according to Sarnat and Sarnat, prediction of outcome is substantially improved by using these brain structure T1-weighted SI comparisons.

Changes in echogenicity in the fetal brain: a prevalence study in fetuses at risk for preterm delivery.

OBJECTIVES: To study the incidence of echodensities in the periventricular white matter, ventricular system, basal ganglia and thalamus of the brain in fetuses at risk for preterm delivery. METHODS: This was a prospective study of 124 fetuses with a gestational age between 26 and 34 weeks in pregnancies affected by either pregnancy-induced hypertensive disorders or preterm labor. Transvaginal ultrasound examination of the fetal brain in coronal and sagittal planes was performed weekly until delivery and the neonatal brain was examined within 24 h after delivery. RESULTS: In 66% of all fetuses, echodensities were found in one or more areas of the brain. They were present in the periventricular area in 52% of cases, the intraventricular area in 18% and in the basal ganglia and thalamus area in 28%. Changes in echogenicity were seen throughout the entire gestational-age period studied. Of the periventricular echodensities that exceeded in echodensity that of the choroid plexus, at least 50% persisted after delivery; at least 38% of the intraventricular echodensities and at least 32% of the basal ganglia and thalamus echodensities persisted after delivery. CONCLUSIONS: In high-risk fetuses, echodensities are a frequent finding in several areas in the brain. How far these echodensities are related to future outcome of the infant needs to be investigated.

Differentiating normal myelination from hypoxic-ischemic encephalopathy on T1-weighted MR Images: a new approach.

BACKGROUND AND PURPOSE: Hypoxic-ischemic cerebral changes can be difficult to distinguish from normal myelination on T1-weighted images. We hypothesized that comparing signal intensity (SI) of brain structures on T1-weighted images enables differentiation of myelination from hypoxic-ischemic brain damage. MATERIALS AND METHODS: T1-weighted images, obtained in 57 infants aged 1-104 days and born after a gestational age of 35 weeks or older, were retrospectively evaluated. Subjects were assigned to a patient (n = 23, with perinatal hypoxic-ischemic encephalopathy [HIE] stage 2/3) or a control group (n = 34). In each subject, an SI score was assigned to 19 brain structures on the basis of pairwise comparisons with the other 18 structures. In both groups, mean total SI scores were calculated for the 19 structures. Independent samples t tests assessed whether the mean total score of a structure differed significantly between the 2 groups. Logistic regression assessed which comparison was best to distinguish between the groups and to predict the presence of hypoxic-ischemic injury. RESULTS: In patients, mean total SI scores for posterolateral putamen (PP) and peri-Rolandic cortex (PC) were significantly higher (P = .000 for both). Mean total SI scores of the posterior limb of internal capsule (PLIC) and the corona radiata (CR) were significantly lower in patients (P = .000 and 0.005, respectively). Two comparisons (PLIC versus CR, PP versus PC) were best to distinguish patients and controls and to predict absence or presence of HIE (P < .0001). CONCLUSION: SI changes due to hypoxia-ischemia can be differentiated from normal myelination by comparing SI of 4 brain structures on T1-weighted images.

Hyperechogenicity of the thalamus and basal ganglia in very preterm infants: radiological findings and short-term neurological outcome.

Cerebral ultrasound of preterm infants may show diffuse, bilateral, hyperechogenic "haze" over the thalami and basal ganglia (hyperechogenicity BGT). We explored whether this could be a pathological phenomenon. All cerebral ultrasound examinations performed in 2001 on infants < 35 weeks of age were reviewed. This resulted in a hyperechogenicity and non-hyperechogenicity group. The character of the hyperechogenicity BGT and the presence of concomitant brain lesions were noted. Detailed clinical and follow-up data from a selected group of infants < 32 weeks were reviewed and compared between the 2 groups. The incidence of hyperechogenicity BGT was 11 % (39/359) in infants < 35 weeks and 26 % (37/143) in infants < 32 weeks. Birth weight and gestational age were significantly lower and clinical course was more complicated in the hyperechogenicity group. Concomitant brain lesions were always present. In 12/39 infants with hyperechogenicity BGT, MRI (always performed for other reasons) was available, showing signal intensity changes in thalamic region in 5 infants. The neurological outcome at term was less favorable in the hyperechogenicity group, but similar at 1 year. Thus hyperechogenicity BGT mainly occurred in very small, sick infants and was always associated with cerebral pathology. MRI did not consistently show abnormalities in the thalamic region. It was not associated with a poorer outcome at 1 year.

Peri- and intraventricular cerebral sonography in second- and third-trimester high-risk fetuses: a comparison with neonatal ultrasound and relation to neurological development.

OBJECTIVES: To determine whether periventricular leukomalacia (PVL) and peri- and intraventricular hemorrhages can be detected in fetuses at risk for preterm birth and to establish the clinical significance of this finding. METHODS: Prenatal cerebral sonography was performed in 26 fetuses at risk for uteroplacental insufficiency on the day of inclusion into the study and weekly until delivery. Neonatal cerebral ultrasound examination was performed within 24 h of birth and biweekly until discharge. The infants underwent standardized neurological examinations. RESULTS: During 30 observations, 21/26 fetuses presented in a cephalic position. Successful visualization in the coronal and sagittal planes was significantly correlated with that of a control population (r = 0.615; 95% CI, 0.390-0.771). In 20/21 fetuses at least one observation was adequate for analysis. Eleven cerebral abnormalities were found in nine fetuses, periventricular echodensities in four, intraventricular hemorrhage in two, and localized thalamic densities in five. In six of these infants ultrasound abnormalities persisted after birth. Neurological follow-up at 24 months demonstrated abnormalities in three infants, two infants were normal and one was lost to follow-up. The three infants with normal ultrasound results after birth had a normal follow-up. Five infants with normal antenatal ultrasound results showed ultrasound abnormalities during the neonatal period; four of them developed PVL Grade 1 and one developed PVL Grade 2. The follow-up of two of these infants was normal, two died and one developed spastic tetraplegia. Abnormal antenatal brain sonography was significantly correlated with gestational age at birth (r = 0.487; P = 0.029). CONCLUSION: Peri- and intraventricular echodensities can be detected reliably before birth in fetuses at high risk for uteroplacental insufficiency. When abnormalities persist, there is a high risk for an adverse outcome.

Dietary supplementation of long-chain polyunsaturated fatty acids in preterm infants: effects on cerebral maturation.

AIM: To study the influence of dietary-supplied long-chain polyunsaturated fatty acids on structural brain maturation in preterm infants and to investigate parameters of functional brain development, relating them to structural maturation. Other studies have suggested that dietary supplementation of long-chain polyunsaturated fatty acids in preterm infants may enhance their visual development. The influence on structural brain development has never been evaluated. METHODS: In a prospective, double-blind study, 42 formula-fed premature infants were randomized to be fed either a standard preterm formula without long-chain polyunsaturated fatty acids or an identical formula supplemented with docosahexaenoic acid (0.015 g/100 ml) and arachidonic acid (0.031 g/100 ml). Infants with significant cerebral damage, retinopathy, chronic disease or feeding problems were excluded. Follow-up was focused on assessment of cerebral myelination by MRI. Psychomotor, mental and visual development was analysed and flash-visual evoked potentials were recorded. RESULTS: It was found that progress of myelination, mental and motor development and latencies of visual evoked potentials were not positively influenced by supplementation of long-chain polyunsaturated fatty acids. At each test age, visual acuity was slightly better in the supplemented infants than in the non-supplemented infants, but the difference never reached significance level CONCLUSION: Supplementation of long-chain polyunsaturated fatty acids did not have a demonstrable positive influence on structural brain maturation. Related to this finding, in this small cohort of preterm infants without significant neurological damage, sample size being restricted by strict inclusion criteria and MRI procedures, no significant positive effects were found on psychomotor, mental and visual development.

[Diagnostic imaging of brain maturation in premature infants]. / Beeldvorming van de hersenontwikkeling bij te vroeg geborenen.

In 3 studies brain maturation in 42 preterm infants with no or minor cerebral deviations was examined with MRI. With a scoring system 5 stadia in gyral development were recognized, which corresponded to the gestational age (duration of amenorrhoea of the pregnant woman). At a gestational age between 30 and 34 weeks, myelin was present in many brain stem, diencephalic and cerebellar structures, but only in a few hemispheric structures. Little progress in myelination was noticed up to the gestational age of 46 weeks. Remnants of the germinal matrix formed a sharp contrast with the immature unmyelinated periventricular white matter and had a characteristic appearance on MR images before term age. Broad periventricular zones with subtle change of signal intensity were also physiological in this age group. Zones with more outspoken signal intensity change compared with the rest of the cerebral white matter were, however, not physiological and represent mild ischaemic change of the periventricular white matter.

Ultrasonography of the peri- and intraventricular areas of the fetal brain between 26 and 36 weeks' gestational age; a comparison with neonatal ultrasound.

OBJECTIVES: To determine to what extent the peri- and intraventricular areas of the fetal brain can be visualized in coronal and sagittal planes using high-frequency transvaginal ultrasound. DESIGN: In a longitudinal study, fetuses of 30 low-risk pregnancies were studied at 26, 28, 30, 32, 34 and 36 weeks' gestational age. The neonates were examined within the first week of life. Visualization of the peri- and intraventricular areas was systematically scored in six coronal and five sagittal planes. The degree of echogenicity of the periventricular area was assessed. Inter- and intra-observer agreements were calculated. RESULTS: For fetuses in the cephalic position, the highest percentages of visualization of the planes were obtained between 26 and 32 weeks' gestational age (> 70% in four coronal and three sagittal planes). Transient periventricular echodensities were observed at 26 and 28 weeks' gestational age in 6/39 observations in the cephalic position. Small choroid plexus cysts were found in three fetuses with the changes persisting in two until after birth. Seven neonates developed mild periventricular echodensities/translucencies not present during fetal development. The mean interobserver agreement was 0.77 (95% confidence interval (CI) 0.73-0.81). The intra-observer agreement varied between 0.48 and 0.72 (mean 0.6, 95% CI 0.47-0.75). CONCLUSIONS: Transvaginal ultrasonography can be applied as a diagnostic tool to evaluate the peri- and intraventricular areas of the fetal brain. Transient periventricular densities can be encountered between 26 and 28 weeks. Term low-risk neonates may develop transient periventricular densities or translucencies.

Early MR features of hypoxic-ischemic brain injury in neonates with periventricular densities on sonograms.

BACKGROUND AND PURPOSE: In the early 1980s, diagnosing periventricular leukomalacia (PVL) in neonates by using cranial sonography was possible for the first time. Our purpose was to investigate the possibility of diagnosing PVL in the acute stage by using MR imaging. We evaluated early MR features of hypoxic-ischemic brain injury in neonates with periventricular densities (flares) on cranial sonograms to determine the added value of MR imaging over sonography alone for early diagnosis of brain damage. METHODS: In a prospective study, infants who showed flares and/or cysts on sonograms underwent MR imaging during the (sub)acute stage. RESULTS: Fifty infants were classified according to the highest sonographic grade up to the day of MR imaging: 23 infants had sonographic grade 1 (flares < 1 week), 15 had sonographic grade 2 (flares > or = 1 week), four had sonographic grade 3 (small localized cysts), and eight had sonographic grade 4 (extensive periventricular cysts); none had sonographic grade 5 (multicystic leukomalacia) on the day of MR imaging. Overall, the additional information provided by MR imaging (over sonography alone) consisted of the depiction of hemorrhagic lesions in 64% of the infants. Extent and severity of the hemorrhages varied from isolated punctate lesions to extensive hemorrhages throughout the white matter; the latter were followed by cystic degeneration at autopsy in two infants. In nine of the 12 infants with cystic PVL, MR images showed more numerous or more extensive cysts. In addition, in two infants, MR images showed cysts not present on sonograms. In 32% of the infants, MR imaging provided no additional information; in these children, all but one had flares on sonograms whereas MR images showed no abnormalities or a zone of mild periventricular signal change. CONCLUSION: MR imaging can depict the precise site and extent of hypoxic-ischemic brain injury at an earlier stage and allows a wider differentiation of lesions as compared with sonography alone. Hemorrhagic PVL is considered to be rare, but was present in 64% of our study population.

Predictive value of neonatal MRI as compared to ultrasound in premature infants with mild periventricular white matter changes.

A follow-up study was performed in 42 premature infants in whom serial neonatal ultrasound and a single neonatal MRI of the brain was normal, or showed mild periventricular white matter changes. The aim of the study was to evaluate the clinical significance of periventricular signal intensity changes on MRI and to compare the predictive value of neonatal MRI with that of ultrasound. The infants underwent repeated standardised motor assessments and developmental tests. MRI was repeated at the corrected age of 12 months. Pronounced periventricular signal intensity changes on neonatal MRI and periventricular echodensities (flaring) on ultrasound were associated with a high incidence of transient motor problems during infancy. The degree of echogenicity carried the highest predictive value, as compared to duration of flaring on ultrasound and degree of periventricular signal intensity change on MRI. It is concluded that signal intensity changes on neonatal MRI represent the same ischaemic change of the periventricular white matter as flaring on ultrasound and that routine neonatal MRI screening is not warranted in premature infants without clinical evidence of neurological problems and with normal or mildly abnormal ultrasound scans. Recording of the degree of echogenicity should become a routine procedure in neonatal cerebral ultrasonography.