Knowledge about extracardiac anomalies (ECA) in fetal congenital heart disease (CHD) can improve our understanding of the developmental origins of various outcomes in these infants. The prevalence and spectrum of ECA, including structural brain anomalies (SBA), on magnetic resonance imaging (MRI) in fetuses with different types of CHD and at different gestational ages, is unknown. The purpose of this study was to evaluate ECA rates and types on MRI in fetuses with different types of CHD and across gestation. A total of 429 consecutive fetuses with CHD and MRI between 17 and 38 gestational weeks were evaluated. ECA and SBA rates were assessed for each type of CHD and classified by gestational age (<25 or ≥25 weeks) at MRI. Of all 429 fetuses with CHD, 243 (56.6%) had ECA on MRI, and 109 (25.4%) had SBA. Among the 191 fetuses with normal genetic testing results, the ECA rate was 54.5% and the SBA rate 19.4%. Besides SBA, extrafetal (21.2%) and urogenital anomalies (10.7%) were the most prevalent ECA on MRI in all types of CHD. Predominant SBA were anomalies of hindbrain-midbrain (11.0% of all CHD), dorsal prosencephalon (10.0%) development, and abnormal cerebrospinal fluid spaces (10.5%). There was no difference in the prevalence or pattern of ECA between early (<25 weeks; 45.7%) and late (≥25 weeks; 54.3%) fetal MRI. ECA and SBA rates on fetal MRI are high across all types of CHD studied, and ECA as well as SBA are already present from midgestation onward.

Purpose: To investigate the reproducibility of radiomics features extracted from two-dimensional regions of interest (2D ROIs) versus whole lung (3D) ROIs in repeated in-vivo fetal magnetic resonance imaging (MRI) acquisitions. Methods: Thirty fetal MRI scans including two axial T2-weighted acquisitions of the lungs were analysed. 2D (lung at the level of the carina) and 3D (whole lung) ROIs were manually segmented using ITK-Snap. Ninety-five radiomics features were extracted from 2 and 3D ROIs in initial and repeat acquisitions using Pyradiomics. Radiomics feature intra-class correlation coefficients (ICC) were calculated between 2 and 3D ROIs in the initial acquisition, and between 2 and 3D ROIs in repeated acquisitions, respectively. Results: MRI data of 11 (36.7%) female and 19 (63.3%) male fetuses acquired at a median 25 + 0 gestational weeks plus days (GW) (interquartile range [IQR] 23 + 4 − 27 + 0 GW) were assessed. Median radiomics feature ICC between 2 and 3D ROIs in the initial MRI acquisition was 0.733 (IQR 0.313–0.814, range 0.018–0.970). ICCs between radiomics features extracted using 3D ROIs in initial and repeat acquisitions (median 0.908 [IQR 0.824–0.929, range 0.335–0.996]) were significantly higher compared to 2D ROIs (0.771 [0.699–0.835, 0.048–0.965]) (p < 0.001). Conclusion: Fetal MRI radiomics features extracted from 3D whole lung segmentation masks showed significantly higher reproducibility across repeat acquisitions compared to 2D ROIs. Therefore, fetal MRI whole lung radiomics features are robust diagnostic and potentially prognostic tools in the image-based in-vivo quantitative assessment of lung development.

Introduction: Fetal tumors are rare and usually followed by poor outcome. We describe our single‐center experience with fetal tumors evaluated by ultrasound and magnetic resonance imaging (MRI). Our aims were to evaluate mortality and morbidity including long‐term outcome and to determine which ultrasound and MRI characteristics were helpful for pre‐ and perinatal management.Material and methods: We conducted a retrospective analysis on prenatally diagnosed tumors between 1998 and 2018. Poor outcome included fetal or neonatal death and survival with serious illness. MRI addressed tumor morphology (sacrococcygeal teratomas), compromise of surrounding structures (head and neck tumors) and early depiction of brain alterations specific to tuberous sclerosis (rhabdomyomas).Results: Of 68 pregnancies, 15 (22%) were terminated and eight children (8/53, 15%) died pre‐ or postnatally. Of the 45 survivors (45/68, 66%), 24 (24/45, 53%) were healthy, eight (8/45, 18%) had a minor illness and 13 (13/45, 29%) a serious illness. Diffusion‐ and T1‐weighted MRI reliably predicted tumor morphology in teratomas. To detect head and neck tumors critical to airway obstruction, MRI was superior to ultrasound in delivery planning. Rhabdomyomas were frequently associated with tuberous sclerosis, regardless of their number or size in ultrasound; MRI could depict specific brain alterations from the early third trimester onwards. For several rare tumors, MRI provided critical differential diagnoses that could not be clearly displayed in ultrasound.Conclusions: The rate of survivors with serious long‐term illness among fetuses with prenatal diagnosis of a tumor was high. MRI is specifically helpful for risk stratification in fetal teratomas and delivery planning in head and neck tumors.

Congenital heart disease is associated with an increased risk of smaller brain volumes and structural brain damage, and impaired growth of supratentorial brain structures in utero has been linked to poor neurodevelopmental outcomes. However, little is known on brainstem and cerebellar volumes in fetuses with congenital heart disease. Moreover, it is not clear whether impaired infratentorial growth, if present, is associated with only certain types of fetal cardiac defects or with supratentorial brain growth, and whether altered biometry is already present before the third trimester. This study aimed to investigate brainstem and cerebellar volumes in fetuses with congenital heart disease and to compare them to infratentorial brain volumes in fetuses with normal hearts. Secondarily, the study aimed to identify associations between infratentorial brain biometry and the type of cardiac defects, supratentorial brain volumes, and gestational age. In this retrospective case-control study, 141 magnetic resonance imaging studies of 135 fetuses with congenital heart disease and 141 magnetic resonance imaging studies of 125 controls with normal hearts at 20 to 37 gestational weeks (median, 25 weeks) were evaluated. All cases and controls had normal birthweight and no evidence of structural brain disease or genetic syndrome. Six types of congenital heart disease were included: tetralogy of Fallot (n=32); double-outlet right ventricle (n=22); transposition of the great arteries (n=27); aortic obstruction (n=24); hypoplastic left heart syndrome (n=22); and hypoplastic right heart syndrome (n=14). First, brainstem and cerebellar volumes of each fetus were segmented and compared between cases and controls. In addition, transverse cerebellar diameters, vermian areas, and supratentorial brain and cerebrospinal fluid volumes were quantified and differences assessed between cases and controls. Volumetric differences were further analyzed according to types of cardiac defects and supratentorial brain volumes. Finally, volume ratios were created for each brain structure ([volume in fetus with congenital heart disease/respective volume in control fetus] × 100) and correlated to gestational age. Brainstem (cases, 2.1 cm³ vs controls, 2.4 cm³; P<.001) and cerebellar (cases, 3.2 cm³ vs controls, 3.4 cm³; P<.001) volumes were smaller in fetuses with congenital heart disease than in controls, whereas transverse cerebellar diameters (P=.681) and vermian areas (P=.947) did not differ between groups. Brainstem and cerebellar volumes differed between types of cardiac defects. Overall, the volume ratio of cases to controls was 80.8% for the brainstem, 90.5% for the cerebellum, and 90.1% for the supratentorial brain. Fetuses with tetralogy of Fallot and transposition of the great arteries were most severely affected by total brain volume reduction. Gestational age had no effect on volume ratios. The volume of the infratentorial brain, which contains structures considered crucial to brain function, is significantly smaller in fetuses with congenital heart disease than in controls from midgestation onward. These findings suggest that impaired growth of both supra- and infratentorial brain structures in fetuses with congenital heart disease occurs in the second trimester. Further research is needed to elucidate associations between fetal brain volumes and neurodevelopmental outcomes in congenital heart disease.

BACKGROUND AND PURPOSE: On the basis of a single multidynamic multiecho sequence acquisition, SyMRI generates a variety of quantitative image data that can characterize tissue-specific properties. The aim of this retrospective study was to evaluate the feasibility of SyMRI for the qualitative and quantitative assessment of fetal brain maturation. MATERIALS AND METHODS: In 52 fetuses, multidynamic multiecho sequence acquisitions were available. SyMRI was used to perform multidynamic multiecho–based postprocessing. Fetal brain maturity was scored qualitatively on the basis of SyMRI-generated MR imaging data. The results were compared with conventionally acquired T1-weighted/T2-weighted contrasts as a standard of reference. Myelin-related changes in T1-/T2-relaxation time/relaxation rate, proton density, and MR imaging signal intensity of the developing fetal brain stem were measured. A Pearson correlation analysis was used to detect correlations between the following: 1) the gestational age at MR imaging and the fetal brain maturity score, and 2) the gestational age at MR imaging and the quantitative measurements. RESULTS: SyMRI provided images of sufficient quality in 12/52 (23.08%) (range, 23 + 6–34 + 0) fetal multidynamic multiecho sequence acquisitions. The fetal brain maturity score positively correlated with gestational age at MR imaging (SyMRI: r = 0.915, P < .001/standard of reference: r = 0.966, P < .001). Myelination-related changes in the T2 relaxation time/T2 relaxation rate of the medulla oblongata significantly correlated with gestational age at MR imaging (T2-relaxation time: r = –0.739, P = .006/T2-relaxation rate: r = 0.790, P = .002). CONCLUSIONS: Fetal motion limits the applicability of multidynamic multiecho–based postprocessing. However, SyMRI-generated image data of sufficient quality enable the qualitative assessment of maturity-related changes of the fetal brain. In addition, quantitative T2 relaxation time/T2 relaxation rate mapping characterizes myelin-related changes of the brain stem prenatally. This approach, if successful, opens novel possibilities for the evaluation of structural and biochemical aspects of fetal brain maturation.

BACKGROUND AND PURPOSE: Although “corpus callosum agenesis” is an umbrella term for multiple entities, prenatal counseling is based reductively on the presence (associated) or absence (isolated) of additional abnormalities. Our aim was to test the applicability of a fetal MR neuroimaging score in a cohort of fetuses with prenatally diagnosed isolated corpus callosum agenesis and associated corpus callosum agenesis and correlate it with neurodevelopmental outcomes. MATERIALS AND METHODS: We performed a single-center retrospective analysis of a cohort of cases of consecutive corpus callosum agenesis collected between January 2011 and July 2019. Cases were scored by 2 raters, and interater agreement was calculated. Outcome was assessed by standardized testing (Bayley Scales of Infant and Toddler Development, Kaufman Assessment Battery for Children) or a structured telephone interview and correlated with scores using 2-way ANOVA. RESULTS: We included 137 cases (74 cases of isolated corpus callosum agenesis), imaged at a mean of 27 gestational weeks. Interrater agreement was excellent (0.98). Scores were higher in associated corpus callosum agenesis (P < .0001) without a significant score difference between complete and partial corpus callosum agenesis (P = .38). Outcome was assessed in 42 children with isolated corpus callosum agenesis and 9 with associated corpus callosum agenesis (mean age, 3.1 years). MR imaging scores correctly predicted developmental outcome in 90.7% of patients with isolated corpus callosum agenesis, improving neurodevelopmental risk stratification in corpus callosum agenesis. CONCLUSIONS: The scoring system is very reproducible and can differentiate isolated corpus callosum agenesis and associated isolated corpus callosum agenesis (significantly higher scores) but not between partial and complete corpus callosum agenesis. Scores correlated with outcome in isolated corpus callosum agenesis, but there were too few associated postnatal cases of isolated corpus callosum agenesis to draw conclusions in this group.