The use of in utero MRI to supplement ultrasound in the foetus at high risk of developmental brain or spine abnormality

Comparison of ultrasound and magnetic resonance imaging findings in evaluation of fetal congenital anomalies: A single-institution prospective observational study

Background

This study aimed to compare the ultrasound (USG) and fetal magnetic resonance imaging (MRI) findings in the evaluation of congenital fetal anomalies and to determine whether the management is changes significantly if MRI is combined with USG.

Methods

In this prospective observational cohort study, we performed fetal MRI in 90 consecutive cases of fetuses diagnosed or suspected as having congenital anomalies on a prior level II USG scan. We then compared the USG and MRI findings of each anomaly according to the diagnostic information yielded by each modality.

Results

Of 90 fetuses examined during 1 year study period, MRI and USG findings were equivalent in 13.3% of cases. MRI provided additional information in 68.8% cases, of which pregnancy management was changed in 5.6% cases. MRI provided additional information but did not change management in 63.3% of cases. USG provided additional information but did not change pregnancy management in 17.8% of cases. The difference was statistically significant with a p value of .000.

Conclusion

Fetal MRI is a significantly better modality than USG for detecting additional findings in anomalies of specific organ systems. Because of its high diagnostic yield for central nervous system (CNS) anomalies, it can be combined with USG for this subgroup. For non-CNS anomalies of genitourinary system, thorax, or in syndromic/complex malformations/conjoint twin pregnancy, it may be used as an adjunct to USG on a case to case basis. MRI has the potential to change the pregnancy management in few cases, but benefit is small to advocate a complete integration of MRI and USG for fetal anomaly scanning at present.

Added value of fetal MRI as a complementary method to antenatal ultrasound in the assessment of non-CNS fetal congenital anomalies

Background

Birth defects and congenital anomalies are different words used to describe developmental abnormalities that occur at birth. Congenital anomalies diagnosis during pregnancy is a difficult topic to which ultrasonography has made significant contributions. The availability of a generally safe, independent technique in the evaluation of prenatal anomalies would be a welcomed clinical and scientific alternative. Ultrasound (US) is the predominant modality for evaluating disorders related to fetus and pregnancy. In most situations, this examination by a professional operator offers sufficient information about fetal morphology, surroundings, and well-being. The abnormalities revealed by ultrasound can be subtle or inconclusive at times. MRI has been demonstrated to be useful in such circumstances in various studies. So the effective use of fetal MRI in the evaluation of non-CNS abnormalities of the body is a reason for adopting fetal MRI as an adjunct to US in obstetric imaging. This study aimed to examine the role of fetal MRI as a complementary method to the antenatal US in assessing non-CNS anomalies and how it changed or modified the diagnosis of anomalies.

Results

By analyzing the data of 30 pregnant females with fetal non-CNS congenital anomalies, the diagnostic accuracy of prenatal ultrasound alone in the detection of congenital anomalies was 76%, with a sensitivity of about 76%. And diagnostic accuracy of MRI alone was 96.6%, with a sensitivity of approximately 96.6%. Moreover, the diagnostic accuracy of combined prenatal US and prenatal MRI in the detection of congenital anomalies was 100%, with sensitivity about 100% and PPV about 100%.

Conclusion

Fetal MRI raises confidence in non-CNS malformation assessment. Compared to US, MRI overcomes many of the obstacles faced by the antenatal US. MRI is superior to the US in refining, changing, or adding more diagnostic information about the disease.

Fetal brain imaging: A comparison between fetal ultrasonography and intra uterine magnetic resonance imaging (a systematic review and meta-analysis)

OBJECTIVE

The aim of this study was to compare ultrasound (US) and intra uterine MRI (IUMRI) of the brain in the diagnosis of fetal brain abnormalities.

METHODS

The present systematic review is done based on guidelines for preferred reporting items for systematic reviews and meta-analysis. All major articles comparing fetal US with IUMRI in fetuses with suspected brain abnormalities were qualified. Articles published before 2010 were excluded from the study. An I²  > 20% was considered as a sign of significant change. The statistical analysis was done using STATA -15 and Meta-Disk 1.4 applications.

RESULTS

Five articles were considered for meta-analysis. The sensitivity of US and IUMRI in diagnosing fetal abnormalities were 86% and 95%, respectively. The corresponding rates for specificity were 77% and 80%. IUMRI and US were concordant in 72.5% (95% CI: 68%-77%) of diagnoses. However, IUMRI added information in 21.7% of cases, while US added value was only 1.48.

CONCLUSION

Our results approved the good diagnostic performance of both US and IUMRI in confirming fetal brain normal development and emphasized that US is an appropriate screening technique in pregnancy. In cases of detected abnormalities in US, IUMRI is suggested as it was the most accurate imaging method and added information about the diagnosis in 22.2% of cases.

Fetal brain MRI: how it added to ultrasound diagnosis of fetal CNS anomalies-1 year experience

Background

Central nervous system (CNS) anomalies are the most commonly diagnosed abnormalities of all fetal malformations and are usually primarily discovered on routine prenatal ultrasonography (US). Fetal magnetic resonance imaging (MRI) is a non-invasive technology with high soft tissue contrast that is documented to increase the diagnostic accuracy for detection of fetal brain anomalies.

The aim of our study is to analyze the value of adding magnetic resonance imaging (MRI) of the fetal brain to antenatal ultrasound in the diagnosis of fetal central nervous system (CNS) anomalies.

Results

We diagnosed various CNS anomalies including twelve cases with infra- and supra-tentorial arachnoid cysts, six cases had Dandy-Walker malformation (DWM) and its variants, 1 case with mega cisterna magna, 2 cases of holoprosencephaly, 1 case of hydranencephaly, 2 cases with supratentorial hydrocephalus, 1 case of craniopharyngioma, 6 cases with corpus callosum (CC) agenesis, 1 case of extradural hematoma, and 8 cases with Meckel-Gruber syndrome (MGS). MRI diagnosis confirmed the ultrasound finding, without additional information in 23 cases (57.5%%), added an extra finding in 11 cases (27.5%), differentiated between 2 pathologies in 3 cases (7.5%), and changed the diagnosis in 3 cases (7.5 %).

The 40 pregnancies resulted in 27 births (67.5%), 2 died directly after birth (5%), 7 terminations (17.5%), and 4 intrauterine fetal deaths (IUFD) (10 %).

Conclusion

Ultrasound is the gold standard imaging modality for anomaly scan in the second and third trimesters; however, MRI of the fetal brain might be a clinically valuable complement especially when ultrasound examination is inconclusive due to maternal obesity, severe oligohydramnios, or in complicated cases with unclear diagnosis.

Apert syndrome diagnosed by prenatal ultrasound combined with magnetic resonance imaging and whole exome sequencing: A case report

BACKGROUND

Most cases of Apert syndrome (AS) are found after birth. Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging (MRI) and whole exome sequencing (WES) during pregnancy are rare.

CASE SUMMARY

We present the case of a 34-year old female patient (gravida 2, para 1) whose fetus was diagnosed with AS during pregnancy. Fetal ultrasound performed at 30, 2/7 wk of pregnancy showed abnormalities. MRI and three-dimensional ultrasound performed at 31, 1/7 wk of pregnancy showed the possibility of AS. Chromosome examination and core family WES were conducted at 31, 5/7 wk of pregnancy. The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide, and AS was confirmed.

CONCLUSION

This case highlights the importance of imaging examinations. Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately, which can be confirmed by WES.

"He looks gorgeous" - iuMR images and the transforming of foetal and parental identities

The MERIDIAN study examined whether in-utero MRI (iuMRI) improves the accuracy of diagnosis of foetal brain abnormalities, when used as an adjunct to ultrasound anomaly scanning. A diagnostic iuMRI differs from routine ultrasound screening because of its infrequent use and scanning procedure. Nested within this trial, this sociological study explored the acceptability of iuMRI as a technology and its contribution to parental decision-making. Our sociological interpretation of the role of iuMR images in prenatal diagnosis draws on narrative interviews with women (and some partners) who underwent MRI imaging at three different centres. Overall, participants found iuMRI helpful in decision-making because it either confirmed or disconfirmed previous results, or provided additional information. Expectant couples experienced the iuMR imaging process as informative, but also as having emotive and practical value. Our paper extends the existing sociological literature on antenatal testing and visualising the foetus, by using iuMR diagnostic imaging to further explore the concept of the unborn entity. Our data suggest that alongside the iuMR images, the 'parental gaze' and accompanying commentary are used by parents to construct and transform foetal and parental identities despite ongoing uncertainties about, and shifting social contexts to their pregnancy.

Diagnostic accuracy of ultrasonography and magnetic resonance imaging for the detection of fetal anomalies: a blinded case-control study

OBJECTIVES

To compare the accuracy of two-dimensional ultrasound (2D-US), three-dimensional ultrasound (3D-US) and magnetic resonance imaging (MRI) for the diagnosis of congenital anomalies without prior knowledge of indications and previous imaging findings.

METHODS

This was a prospective, blinded case-control study comprising women with a singleton pregnancy with fetal congenital abnormalities identified on clinical ultrasound and those with an uncomplicated pregnancy. All women volunteered to undergo 2D-US, 3D-US and MRI, which were performed at one institution. Different examiners at a collaborating institution performed image interpretation. Sensitivity and specificity of the three imaging methods were calculated for individual anomalies, based on postnatal imaging and/or autopsy as the definitive diagnosis. Diagnostic confidence was graded on a four-point Likert scale.

RESULTS

A total of 157 singleton pregnancies were enrolled, however nine cases were excluded owing to incomplete outcome, resulting in 148 fetuses (58 cases and 90 controls) included in the final analysis. Among cases, 13 (22.4%) had central nervous system (CNS) anomalies, 40 (69.0%) had non-CNS anomalies and five (8.6%) had both CNS and non-CNS anomalies. The main findings were: (1) MRI was more sensitive than 3D-US for diagnosing CNS anomalies (MRI, 88.9% (16/18) vs 3D-US, 66.7% (12/18) vs 2D-US, 72.2% (13/18); McNemar's test for MRI vs 3D-US: P = 0.046); (2) MRI provided additional information affecting prognosis and/or counseling in 22.2% (4/18) of fetuses with CNS anomalies; (3) 2D-US, 3D-US and MRI had similar sensitivity for diagnosing non-CNS anomalies; (4) specificity for all anomalies was highest for 3D-US (MRI, 85.6% (77/90) vs 3D-US, 94.4% (85/90) vs 2D-US, 92.2% (83/90); McNemar's test for MRI vs 3D-US: P = 0.03); and (5) the confidence of MRI for ruling out certain CNS abnormalities (usually questionable for cortical dysplasias or hemorrhage) that were not confirmed after delivery was lower than it was for 2D-US and 3D-US.

CONCLUSIONS

MRI was more sensitive than ultrasonography and provided additional information that changed prognosis, counseling or management in 22.2% of fetuses with CNS anomalies. False-positive diagnoses for subtle CNS findings were higher with MRI than with ultrasonography. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Central Nervous System Anomalies Detected by Magnetic Resonance Imaging: A Two-Year Experience

BACKGROUND

Magnetic resonance imaging (MRI) is gradually becoming more common for thorough visualization of the fetus than ultrasound (US), especially for neurological anomalies, which are the most common indications for fetal MRI and are a matter of concern for both families and society.

OBJECTIVES

We investigated fetal MRIs carried out in our center for frequency of central nervous system anomalies. This is the first such report in southern Iran.

MATERIALS AND METHODS

One hundred and seven (107) pregnant women with suspicious fetal anomalies in prenatal ultrasound entered a cross-sectional retrospective study from 2011 to 2013. A 1.5 T Siemens Avanto scanner was employed for sequences, including T2 HASTE and Trufisp images in axial, coronal, and sagittal planes to mother's body, T2 HASTE and Trufisp relative to the specific fetal body part being evaluated, and T1 flash images in at least one plane based on clinical indication. We investigated any abnormality in the central nervous system and performed descriptive analysis to achieve index of frequency.

RESULTS

Mean gestational age ± standard deviation (SD) for fetuses was 25.54 ± 5.22 weeks, and mean maternal age ± SD was 28.38 ± 5.80 years Eighty out of 107 (74.7%) patients who were referred with initial impression of borderline ventriculomegaly. A total of 18 out of 107 (16.82%) patients were found to have fetuses with CNS anomalies and the remainder were neurologically normal. Detected anomalies were as follow: 3 (16.6%) fetuses each had the Dandy-Walker variant and Arnold-Chiari II (with myelomeningocele). Complete agenesis of corpus callosum, partial agenesis of corpus callosum, and aqueductal stenosis were each seen in 2 (11.1%) fetuses. Arnold-Chiari II without myelomeningocele, anterior spina bifida associated with neurenteric cyst, arachnoid cyst, lissencephaly, and isolated enlarged cisterna magna each presented in one (5.5%) fetus. One fetus had concomitant schizencephaly and complete agenesis of the corpus callosum.

CONCLUSIONS

MRI is superior to ultrasound and physical exam of live births in detection of CNS anomalies. In this investigation within a single referral center in southern Iran, anomalies included Dandy-Walker variant and Arnold-Chiari II as the most common findings. Other findings with lower incidence were complete and partial agenesis of corpus callosum, aqueductal stenosis, anterior spina bifida, schizencephaly, arachnoid cyst, lissencephaly, and isolated enlarged cisterna magna.

Analysis of supratentorial cystic abnormalities using in utero MR imaging

OBJECTIVE

Our anecdotal experience from foetal neuroimaging studies suggests that there are often significant disagreements between the findings of ultrasonography (USS) and in utero MR (iuMR) imaging in cases of antenatally detected supratentorial extra-axial cysts. Although this is a relatively rare clinical situation, it warrants further investigation because of the high risk of other intracranial abnormalities that are likely to cause long-term neurodevelopmental problems.

METHODS

We reviewed 957 consecutive referrals for iuMR of the foetal brain over a 3.5-year period and studied all cases where the referral from USS described supratentorial extra-axial cysts in the foetus. The iuMR imaging was reviewed, and a comparison between the results of the two examinations was made.

RESULTS

Supratentorial extra-axial cysts were an unusual referral for iuMR occurring in only 13/957 (1.4%) of cases. The findings on USS and iuMR imaging were conflicting in all 13 cases with intracranial pathology being excluded on iuMR imaging in 4 cases and more significant pathology being shown in 9 cases. Abnormalities of the corpus callosum were recognized in association with a cyst in eight cases, and this was recognized in only two cases on USS. Six of those cases also had abnormalities of cortical formation.

CONCLUSION

iuMR imaging should be used in the assessment of pregnancies in which a supratentorial extra-axial cyst has been detected on USS. This is based on the improved primary diagnosis and a high rate of associated brain abnormalities not detected on USS.

ADVANCES IN KNOWLEDGE

Our retrospective observational study examines a range of foetal intracranial abnormalities which are better defined using iuMRI. This is a previously described spectrum of neurodevelopmental anomalies which we suggest would benefit from MRI.

Pattern-based approach to fetal congenital cardiovascular anomalies using the transverse aortic arch view on prenatal cardiac MRI

Fetal echocardiography is the imaging modality of choice for prenatal diagnosis of congenital cardiovascular anomalies. However, echocardiography has limitations. Fetal cardiac magnetic resonance imaging (MRI) has the potential to complement US in detecting congenital cardiovascular anomalies. This article draws on our experience; it describes the transverse aortic arch view on fetal cardiac MRI and important clues on an abnormal transverse view at the level of the aortic arch to the diagnosis of fetal congenital cardiovascular anomalies.

The Reliability of Fetal MRI in the Assessment of Brain Malformations

Objectives: To assess the inter- and intraobserver reliability of different fetal MRI measurements in cases of fetal brain malformations and to examine the concordance between ultrasonography (US) and MRI findings. Methods: Fetal brain MRIs and US findings of 56 pregnant women were retrieved from the institutional database. Standardized fetal brain MRI measurements were performed by 4 observers, and the inter- and intraobserver reliability was determined. Additionally, US and MRI findings were retrospectively compared. Results: The interobserver intraclass correlation coefficient (ICC) was above 0.9 for the cerebellum and posterior horn of the lateral ventricle. The measurements regarding the third ventricle (0.50), the fourth ventricle (0.58), and the corpus callosum (0.63) showed poor reliability. Overall, the intraobserver reliability was greater than the interobserver reliability. US and MRI findings were discordant in 29% of the cases with MRI rendering an extended diagnosis in 18%, a change of diagnosis in 3.6%, and excluding pathological findings suspected on US in 7.1%. Conclusions: Fetal MRI is a valuable complement to US in the investigation of fetal brain malformations. The reliability of most parameters was high, except for the measurements of the third and fourth ventricles and the corpus callosum.

Accuracy of neurosonography and MRI in clinical management of fetuses referred with central nervous system abnormalities

OBJECTIVE

To assess the accuracy of expert neurosonography (two- and three-dimensional NSG) in the characterization of major fetal central nervous system (CNS) anomalies seen at a tertiary referral center and to report the differential clinical usefulness of magnetic resonance imaging (MRI) used as a second-line diagnostic procedure in the same cohort.

METHODS

This was a retrospective analysis of all 773 fetuses with confirmed CNS abnormalities referred to our center between 2005 and 2012. The following variables were analyzed: gestational age at NSG and MRI, NSG and MRI diagnoses, indication for MRI (confirmation of NSG findings; diagnostic doubt; search for possible additional brain anomalies), association with other malformations, diagnostic accuracy of NSG vs MRI (no additional clinical value for either MRI or NSG; additional information with clinical/prognostic significance on MRI relative to NSG; additional information with clinical/prognostic significance on NSG relative to MRI, NSG and MRI concordant but incorrect) and final diagnosis, which was made at autopsy or postnatal MRI/surgery.

RESULTS

CNS malformations were associated with other anomalies in 372/773 (48.1%) cases and were isolated in the remaining 401 (51.9%) cases. NSG alone was able to establish the diagnosis in 647/773 (83.7%) cases. MRI was performed in 126 (16.3%) cases. The indication for MRI was: confirmation of NSG diagnosis in 59 (46.8%) cases; diagnostic query (in the case of inconclusive or uncertain finding on NSG) in 20 (15.9%) cases; search for possible additional brain anomalies in 47 (37.3%) cases. NSG and MRI were concordant and correct in 109/126 (86.5%) cases. Clinically relevant findings were evident on MRI alone in 10/126 (7.9%) cases (1.3% of the whole population) and on NSG alone in 6/126 (4.8%) cases; in all six of these cases, MRI had been performed at < 24 weeks of gestation. In one case, both NSG and MRI diagnoses were incorrect. The main type of malformation in w ich MRI played an important diagnostic role was space-occupying lesions, MRI identifying clinically relevant findings in 42.9% (3/7) of these cases.

CONCLUSIONS

(1) In a tertiary referral center with good NSG expertise in the assessment of fetal CNS malformations, MRI is likely to be of help in a limited proportion of cases; (2) MRI is more useful after 24 weeks of gestation; (3) the lesions whose diagnosis is most likely to benefit from MRI are gross space-occupying lesions.