Ganglionic Eminence Anomalies and Coexisting Cerebral Developmental Anomalies on Fetal MR Imaging: Multicenter-Based Review of 60 Cases.

BACKGROUND AND PURPOSE: The ganglionic eminences are transient fetal brain structures that produce a range of neuron types. Ganglionic eminence anomalies have been recognized on fetal MR imaging and anecdotally found in association with a number of neurodevelopmental anomalies. The aim of this exploratory study was to describe and analyze the associations between ganglionic eminence anomalies and coexisting neurodevelopmental anomalies. MATERIALS AND METHODS: This retrospective study includes cases of ganglionic eminence anomalies diagnosed on fetal MR imaging during a 20-year period from 7 centers in Italy and England. Inclusion criteria were cavitation or increased volume of ganglionic eminences on fetal MR imaging. The studies were analyzed for associated cerebral developmental anomalies: abnormal head size and ventriculomegaly, reduced opercularization or gyration, and abnormal transient layering of the developing brain mantle. The results were analyzed using χ2 and Fisher exact tests. RESULTS: Sixty fetuses met the inclusion criteria (21 females, 24 males, 15 sex unknown). Thirty-four had ganglionic eminence cavitations (29 bilateral and 5 unilateral), and 26 had increased volume of the ganglionic eminences (19 bilateral, 7 unilateral). Bilateral ganglionic eminence cavitations were associated with microcephaly (P = .01), reduced opercularization, (P < .001), reduced gyration (P < .001), and cerebellar anomalies (P = .01). Unilateral ganglionic eminence cavitations were not significantly associated with any particular feature. Bilateral increased volume of the ganglionic eminences showed an association with macrocephaly (P = .03). Unilateral increased volume was associated with macrocephaly (P = .002), abnormal transient layering (P = .001), unilateral polymicrogyria (P = .001), and hemimegalencephaly (P < .001). CONCLUSIONS: Ganglionic eminence anomalies are associated with specific neurodevelopmental anomalies with ganglionic eminence cavitations and increased ganglionic eminence volume apparently having different associated abnormalities.

Sonographic diagnosis of hepatic erosion caused by umbilical catheterization.

The use of umbilical venous catheter (UVC) is common practice in neonatal units. The traumatic injury of the hepatic parenchyma is a rare complication. We present a case of a preterm newborn underwent ultrasound examination revealing a hyperechogenic focal lesion at the confluence of the hepatic veins This finding, according to patient's history, was suspected to be a traumatic injury of the liver parenchyma caused by umbilical catheterization. During sonographic follow-up this lesion gradually reduced until complete resolution. Finally, when focal hyperechogenic hepatic lesion is incidentally detected in newborn with history of UVC placement, the radiologists must consider the traumatic etiology.

Fetal MRI as a complement to US in the evaluation of cleft lip and palate.

PURPOSE: The aim of our study was to investigate the role of fetal magnetic resonance imaging (MRI) as a complement to ultrasound (US) in the evaluation of cleft lip and palate (CLP), whether isolated or in association with syndromic conditions. MATERIALS AND METHODS: We enrolled 24 pregnant women (27 fetuses) (mean gestational age 23.7 weeks) with a level-two US diagnosis of cleft lip (CL) or CLP with or without associated central nervous system (CNS) or facial-bone anomalies. All individuals underwent a fetal MRI examination to study the facial skeleton, CNS and fetal body. For each fetus, the main anatomical facial landmarks and biometric parameters [anteroposterior diameter (APD), biparietal diameter (BPD), inferior facial angle (IFA), frontomaxillary angle (FMA), bi-orbital diameter (BOD), intraorbital diameter (IOD)] were measured. RESULTS: Twenty-five of 27 fetuses had a US diagnosis of CL or CLP. MRI confirmed the diagnosis in 16/25 fetuses and added information about the extent of the cleft and the degree of involvement of the anterior and posterior palate in 8/25 fetuses. MRI ruled out the diagnosis in 1/25 fetuses and identified an alteration of the parameters IFA, FMA and IOD in 6/24 fetuses. CONCLUSIONS: In the study of CLP fetal, MRI is able to define the degree of involvement of the posterior palate and the lateral extent of the cleft with higher diagnostic accuracy than US. Furthermore, MRI provides a complete study of the fetal head and biometric development of the facial bones, thus enabling early detection of potential syndromic conditions.

Role of fetal MRI in the diagnosis of cerebral ventriculomegaly assessed by ultrasonography.

PURPOSE: To evaluate the additional diagnostic value of fetal MRI to evaluate cerebral ventriculomegaly assessed by ultrasonography (US) for the possibility to change the diagnosis, the counseling and the management of pregnancy. MATERIALS AND METHODS: From february 2006 to october 2008, we studied 55 pregnant women by fetal MRI (mean age 28 years), 4 with twin pregnancy, for a total of 59 fetuses with mean gestational age of 27 weeks. The number of fetuses affected by ventriculomegaly assessed by US was 55. All fetuses had a US diagnosis of ventriculomegaly: 29 fetuses with isolated ventriculomegaly and 26 fetuses with ventriculomegaly associated with CNS (central nervous system) abnormalities (18) and with no CNS abnormalities (8). RESULTS: The findings showed that the two techniques are substantially in agreement in defining the degree of VM, with the exception of some cases in which the disagreement could be attributed to the possible progression of the dilatation between the US and MRI examinations, which sway between two days and two weeks. We proved a low correlation between US and MRI in the evaluation of ventriculomegaly associated either with CNS or non-CNS anomalies: in fact while fetal MRI detected 26/55 (47,3%) VM associated with CNS anomalies, US demonstrated only 18/55(32,7%). Referring to VM associated with non-CNS anomalies, MRI diagnosed 10/55 cases (18,2%) compared to 8/55 fetuses (14,5%) showed by US. CONCLUSIONS: Our experience demonstrated that fetal MRI has an important role as adjunctive tool to sonography in the evaluation of cerebral ventriculomegaly for the additional informations given to parents and for the possibility to change the diagnosis, the counseling and the management of pregnancy.

Fetal MRI of the cardiovascular system: role of steady-state free precession sequences for the evaluation of normal and pathological appearances.

PURPOSE: This study aimed to evaluate the feasibility of fetal magnetic resonance imaging (MRI) with steady-state free precession (SSFP) sequences to visualise the normal and pathological appearances of the cardiovascular system. MATERIALS AND METHODS: This is a prospective observational study of 83 pregnant women who underwent fetal cardiac MRI: 43 patients (cases) had echocardiographic suspicion of congenital heart disease; 40 patients (controls) did not. Fetal cardiac MRI consisted of a static phase with multiplanar SSFP sequences and a dynamic phase with real-time SSFP sequences. Two radiologists evaluated the diagnostic quality of the SSFP images in both the controls and cases, the MRI morphological and functional features in the controls and the MRI signs of congenital heart disease in the cases. RESULTS: In both groups, SSFP sequences produced goodquality MR images and good visualisation of morphological features. Functional data appeared to be unavailable due to the current small temporal resolution and the technical impossibility of fetal cardiac triggering. MRI detected direct signs of congenital heart disease in 21 fetuses, indirect signs in six and both signs in 15. CONCLUSIONS: SSFP sequences are effective in demonstrating the morphological features of the cardiovascular system, whereas dynamic SSFP cine-MRI sequences may provide adjunctive albeit suboptimal functional information.

Fetal MRI with diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) assessment in the evaluation of renal development: preliminary experience in normal kidneys.

PURPOSE: The study aimed to investigate the correlation between apparent diffusion coefficient (ADC) and gestational age by applying diffusion-weighted imaging (DWI) in the study of normal fetal kidneys. MATERIALS AND METHODS: We performed magnetic resonance (MR) imaging on 88 fetuses (gestational age range 17-40 weeks) after ultrasound had ruled out urinary system malformations. A multiplanar study of the urinary system was obtained by using conventional T2-weighted sequences and echoplanar imaging (EPI). DW sequences with ADC maps were subsequently acquired, and kidney ADC values were correlated with gestational age by diving the fetuses into six groups according to age. RESULTS: We found a correlation between ADC values and gestational age. The ADC values, ranging from 0.99 to 1.62x10(-3) mm(2)/s [mean 1.22; 95% confidence interval (CI) 1.19-1.25, standard deviation (SD) 0.147], showed a tendency to decrease with increasing gestational age. The relationship between ADC values and gestational age was expressed by a linear regression equation: ADC (mm(2)/s)=1.69-0.0169 (GA) (R(2)=37.7%, R(2) ADJ=37.0%, p<0.005, Pearson correlation=-0.614). CONCLUSIONS: DWI with ADC mapping provides functional information on fetal renal parenchyma development and may thus become a useful tool in the management of pregnancy and treatment of the newborn child.

Assessment of congenital heart disease (CHD): is there a role for fetal magnetic resonance imaging (MRI)?

PURPOSE: To review our experience with fetal magnetic resonance imaging (MRI) to evaluate congenital heart disease (CHD). METHODS: We performed fetal MRI in 32 fetuses with an echocardiographically assessed CHD. Both direct and indirect signs of CHD were investigated. Direct signs considered were: morpho-volumetric abnormalities of the heart; malrotations; ventricular and atrial septal defects; anomalies of the origin, size and course of the great arteries. Indirect signs considered were: difficulty to recognize a "normal" anatomical structures in the reference projections; increase of the vascular size before a stenosis; hypertrophy of the papillary muscles; cardiomegaly and pericardial effusion. All MRI findings were compared with postnatal or autoptic findings. RESULTS: MRI allowed the CHD to be visualised by direct signs in 17 fetuses, indirect signs in 5 and both direct and indirect signs in 9 fetuses, excluding the prenatal echocardiographic suspect of hypoplastic left heart syndrome in 1 fetus. Postnatal echocardiograms or autoptic findings confirmed a normal heart in 1 fetus and CHD in 31 fetuses including a single cardiac anomaly or syndrome in 19 fetuses, 2 associated cardiac abnormalities in 11 and 3 cardiac anomalies in 1 fetus. However, in 2 fetuses MRI detected a ventricular septal defect successively disclosed by gold standard. CONCLUSIONS: MRI is a promising method for further assessment of the cardiovascular pathologies diagnosed by echocardiography, and may be a valuable tool in assessing associated extracardiac anomalies.

Magnetic resonance imaging versus ultrasonography in fetal pathology.

PURPOSE: This paper describes our experience with magnetic resonance imaging (MRI) in the assessment of fetal anatomical structures and major fetal pathologies. MATERIALS AND METHODS: The retrospective study included 128 pregnant women between the 22nd and 38th week of gestation. We used the following imaging protocol: T2-weighted single-shot fast spin-echo sequences for all foetuses and, in selected cases, gradient echo with steady-state free precession (SSFP), T1-weighted spoiled gradient echo [fast low-angle shot (FLASH)] with and without fat saturation, and T2 thick-slab sequences with multiplanar technique. In 32 cases, we performed diffusion-weighted sequences with apparent diffusion coefficient (ACD) maps on the brain, the kidneys and the lungs. RESULTS: We achieved diagnostic-quality images in 125 of 128 patients; MR image quality was unsatisfactory in three cases only. In 16 cases with previous negative ultrasound (US) findings, MRI confirmed the US diagnosis. MRI confirmed the positive US diagnosis in 67 of 109 cases (61.5%); in 11 cases it changed the US diagnosis, and in 31/109 the examination was negative. In addition, MRI identified other anomalies not recognised during US examination. CONCLUSIONS: With its ultrafast sequences, fetal MRI provides good detail of normal fetal anatomy and allows characterisation of suspected anomalies.

Evaluation of normal brain development by prenatal MR imaging.

PURPOSE: The aim of this study was to describe the normal pattern of development and maturation of the foetal brain with respect to gestational age as assessed with magnetic resonance imaging (MRI) and to provide an overview of the possibilities of the technique. MATERIALS AND METHODS: Foetal cerebral MRI was performed on 56 pregnant women between 19 and 37 weeks of gestation. Half-Fourier single-shot turbo spin-echo (HASTE), true fast imaging with steady precession (FISP), T1-weighted fast low angle shot (FLASH) two-dimensional (2D) and diffusion-weighted (DW) sequences with apparent diffusion coefficient (ADC) were obtained. Biometric parameters and developmental areas of the cerebral cortex were correlated to gestational age by using the Spearman rank correlation test. RESULT: We found a negative correlation between the germinal matrix/biparietal diameter ratio and gestational age and a positive correlation between the germinal and cortical matrix when expressed as external intraocular diameter ratio (R=0.452, p=0.02). The cortical mantle was correlated with biometric parameters, such as the biparietal diameter and the frontooccipital diameter, and with gestational age. The interhemispheric fissure, the parietooccipital fissure and the sylvian fissure were detectable by the 22nd week. In the grey matter, the mean ADC values varied from 1.76 x 10(-3) mm(2)/s (at week 19) to 0.89 x 10(-3) mm(2)/s (at week 37), whereas in the white matter, the values varied from 2.03 x 10(-3) mm(2)/s (at week 19) to 1.25 x 10(-3) mm(2)/s (at week 37). CONCLUSIONS: MRI provides a reliable valuation of brain maturation during pregnancy.