Situs anomalies on prenatal MRI

Objective

Situs anomalies refer to an abnormal organ arrangement, which may be associated with severe errors of development. Due regard being given to prenatal magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US), this study sought to demonstrate the in utero visualization of situs anomalies on MRI, compared to US.

Materials and methods

This retrospective study included 12 fetuses with situs anomalies depicted on fetal MRI using prenatal US as a comparison modality. With an MRI standard protocol, the whole fetus was assessed for anomalies, with regard to the position and morphology of the following structures: heart; venous drainage and aorta; stomach and intestines; liver and gallbladder; and the presence and number of spleens.

Results

Situs inversus totalis was found in 3/12 fetuses; situs inversus with levocardia in 1/12 fetuses; situs inversus abdominis in 2/12 fetuses; situs ambiguous with polysplenia in 3/12 fetuses, and with asplenia in 2/12 fetuses; and isolated dextrocardia in 1/12 fetuses. Congenital heart defects (CHDs), vascular anomalies, and intestinal malrotations were the most frequent associated malformations. In 5/12 cases, the US and MRI diagnoses were concordant. Compared to US, in 7/12 cases, additional MRI findings specified the situs anomaly, but CHDs were only partially visualized in six cases.

Conclusions

Our initial MRI results demonstrate the visualization of situs anomalies and associated malformations in utero, which may provide important information for perinatal management. Using a standard protocol, MRI may identify additional findings, compared to US, which confirm and specify the situs anomaly, but, with limited MRI visualization of fetal CHDs.     

MRI as complementary tool added to ultrasound in the diagnosis of fetal renal abnormalities – any added value?

Purpose

To assess the potential role of magnetic resonance imaging (MRI) as a complementary diagnostic tool to ultrasonography (US) in the diagnosis of fetal renal anomalies in pregnant women with oligohydramnios in the absence of amniotic membrane rupture.

Methods

Ninety pregnant women, with oligohydramnios were prospectively evaluated using both US and MRI. Prenatal findings were correlated with the babies’ outcome.

Results

MRI studies of diagnostic quality were obtained in all fetuses. The US and MRI findings were concordant in 79 (87.8%) of the fetuses. MRI modified and changed the diagnosis in 11 fetuses (12.2%), these were five fetuses in which US diagnosis was inconclusive, five cases in which the diagnosis changed from bilateral renal agenesis to unilateral agenesis with the other kidney multicystic dysplastic kidney (MCDK), and in the remaining fetuses the modification was from bilateral renal agenesis to unilateral agenesis with the other kidney structurally normal.Concordant findings for the prenatal US and MRI scans were seen in 100% of the autosomal recessive polycystic kidney disease (APCKD), 96% of MCDK, and 92.9% of bilateral normal kidneys.

Conclusion

MRI is of value in cases of oligohydramnios in limited circumstance when US findings were inconclusive.     

Magnetic resonance imaging versus Ultrasound examination in detection of prenatal fetal brain anomalies

Purpose

Evaluation of the role of MR Imaging in detection of fetal brain anomalies versus 2D and 4D Ultrasound examination.

Study design

This study included 23 pregnant females who were suspected to have fetus with congenital brain anomalies over a period of one year using ultrasound. MRI was done within one week following 2D and 4D US examination. The maternal age ranged from 18 to 39 years. The gestational age ranged from 16 to 36 weeks (mean age = 26 weeks). Antenatal Ultrasound and magnetic resonance findings were compared with postnatal MRI findings.

Results

We reported different types of congenital brain anomalies including eight cases of isolated central nervous system anomalies. MRI and ultrasound showed concordant findings in six cases. MRI changed the diagnosis in 14 cases and provided additional information in two cases. Ultrasound was superior to magnetic resonance imaging in one case at second trimester due to fetal motion.

Conclusion

Our results showed that fetal MR imaging is useful in detection of fetal central nervous system anomalies as well as a complementary modality to 2D/4D Ultrasound in diagnosis of fetal central nervous system anomalies.     

Prenatal MR imaging of Dandy-Walker complex: midline sagittal area analysis

Objective

To measure the mid-sagittal areas of vermis (VA) and of posterior fossa (PFA) and determine their differences among fetuses with various Dandy-Walker (DW) entities and control subjects.

Methods

We reviewed data in 25 fetal patients with a MR diagnosis of DW complex including hypoplastic vermis (HV), HV with rotation (HVR), and mega cistern magna (MCM), and in 85 fetal controls with normal CNS. PFA and VA of each subject were manually traced on mid-sagittal MR images. Regarding each of VA and PFA, after age correction, we determined statistically significant differences among HVR, HV, MCM, and control groups.

Results

The mean VA residue of MCM was greater than that of the control, which was in turn greater than those of HVR and HV. The mean PF residue of the control was smaller than all other groups.

Conclusion

Fetuses with HVR or HV had smaller VA than fetuses with MCM or control subjects. Fetuses with MCM, HVR, or HV had larger PFA than control subjects. These results may be an early step leading to better understanding of the confusion about the PF anomalies in future.     

Diagnostic value of four dimensional ultrasound in detection of fetal causes of oligohydraminos: An observational study

Purpose

To evaluate the role of 3-dimensional (3DUS) and 4-dimensional ultrasound (4DUS) in detection of fetal causes of oligohydraminos.

Actual imaging time in fetal MRI

Objective

Safety issues in magnetic resonance imaging (MRI) are important, especially in fetal MRI. However, since basic data with respect of the effective exposure time in fetal MRI are not available, this study aimed to determine the actual imaging time during a fetal MRI study.

Methods

100 fetal MRI studies of singleton pregnancies performed on a 1.5 T system were analysed with respect to study duration (from starting the survey scan until the end of study), the number of sequences acquired, and the actual imaging time, which was calculated by adding up scan time of each sequence. Furthermore, each sequence type was analysed regarding the number of acquisitions, specific absorption rates (SAR), and duration.

Results

Mean study duration was 34.6 min (range: 14–58 min; standard deviation (SD): 9.7 min), the average number of sequences acquired was 26.6 (range: 11–44, SD: 6.6). Actual scan time averaged 11.4 min (range: 4–19 min, SD: 4.0 min). Ultrafast T2-weighted and steady-state free-precession sequences accounted for 62.3% of actual scan time, and were distributed over the whole duration of the study.

Conclusion

Actual imaging time only accounts for 33% of total study time and is not continuous. The remaining time is consumed by the preparation phases of the scanner, and is spent with planning sequences and the eventual repositioning of the coil and/or pregnant woman. These data may help to more accurately estimate the exposure to radiofrequency deposition and noise during fetal MRI studies.     

The effect of nuchal cord on nuchal fold thickness measured in the second trimester

Purpose

To find out whether nuchal cord causes an effect on the nuchal skin fold thickness (NFT) measurements, or not.

Patients and methods

A total of 242 fetuses with normal outcomes that had undergone detailed second trimester US scan between 18 and 24 weeks of gestation were included in the study. NFT measurements were made on axial cranial US images passing through the cerebellum and cavum septi pellucidum. To detect nuchal cord, color Doppler imaging was performed on the axial views of the fetal neck. To investigate the differences in NFT measurements of the fetuses with or without nuchal cord, statistical analysis was performed using Mann–Whitney test. P < 0.05 was considered statistically significant.

Results

The study group was divided into two groups: nuchal cord (+) (n: 26) and nuchal cord (−) (n: 216) fetuses. Mean NFT measurements were 4.66 ± 0.64 mm and 4.36 ± 0.79 mm for nuchal cord (+) and nuchal cord (−) fetuses, respectively. Median NFT measurement for nuchal cord (+) fetuses was 4.6 mm, whereas it was 4.4 mm for nuchal cord (−) fetuses. Statistically significant difference was denoted between two groups, in terms of NFT measurements (P = 0.049).

Conclusion

NFT measurements of fetuses with nuchal cord are higher than the NFT measurements of fetuses without nuchal cord. One can conclude that the nuchal cord (+) fetuses with no other anomalies but increased NFT should be re-scanned to see if the increased NFT resolves in the absence of nuchal cord.     

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.     

A prospective observational study of early fetal growth velocity and its association with birth weight,gestational age at delivery,preeclampsia, and perinatal mortality

Objectives

We aimed to measure early fetal growth velocity and to correlate this with the birth weight, gestational age at delivery, and with the incidence of adverse pregnancy outcomes specifically preeclampsia and perinatal mortality.

Methods

A data based prospective observational study, wherein sonographic biometry data and specific pregnancy outcome related data were collected from pregnant women's records, starting soon after their first antenatal visit. Early fetal growth velocity was measured using BPD growth between 11 and 14 weeks scan and anomaly scan and standardizing this by Z scoring.

Results

Out of 607 fetuses, 41 (6.7%) were slow growing, 531 (87.4%) normally growing, and 35 (5.7%) fast growing (Z scoring <10th^, 10–90th, and >90th percentiles respectively). As fetal growth velocity increased, the mean birth weight decreased from 2958.7 ± 388.9 (<10th centile), 2742.1 ± 576.6 (10–90th centile), to 2339.3 ± 729.4 (>90th centile); and gestational age at delivery decreased from 38.5 ± 1.3 (<10th centile), 37.5 ± 2.1 (10–90th centile), to 36.4 ± 2.2 (>90th centile), and both these trends were statistically significant (p < 0.001).Faster growing fetuses had a higher risk of preterm delivery(spontaneous + indicated) compared to other 2 groups [OR 4.42 (2.18,8.98)], and slower growing fetuses had a higher risk of postdated deliveries compared to other 2 groups [OR 3.042 (1.44, 6.45)].We found no significant association between early fetal growth velocity and incidence of small for gestational age at birth/low birth weight at term, preeclampsia, and perinatal mortality.

Conclusions

Early fetal growth velocity between first and second trimesters, may be one of the important factors influencing ultimate birthweight and gestational age at delivery.     

Tumor disease and associated congenital abnormalities on prenatal MRI

Objective

Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI.

Materials and methods

This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI.

Results

There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head–neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis.

Conclusion

Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases.     

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.     

Coronary artery anomalies: Role of contrast enhanced MDCT coronary angiography

Objective

The purpose of this study is to evaluate the role of MDCT in the depiction of coronary artery anomalies.

Patients and methods

Sixteen patients were included in this study. Retrospectively gated coronary CT angiography was performed in 11 patients and prospectively gated CT coronary angiography was performed in 5 patients. Post-processing techniques as maximum-intensity projection, curved multiplanar reconstruction, and volume rendering were applied to assess the origin and course of the coronary vessels.

Results

Origin and course anomalies of the central coronary artery segments were seen in 11 patients (67%), anomalies of only coronary artery origin in 2 patients (13%), origin and course anomalies of the peripheral coronary segments in 2 patients (13%) and coronary arterio-venous fistula in one patient (7%). The origin and course anomalies of the central coronary artery segment were more common in the left coronary artery involving 8 patients (73%). Malignant inter-arterial course between aortic root and pulmonary artery or the right ventricle outflow tract was seen in 3 anomalous arteries.

Conclusion

MDCT coronary angiography can precisely depict the origin and course coronary artery anomalies and is recommended in young patients and before cardiac intervention or surgery to prevent possible complications.     

Role of three-dimensional ultrasound in the diagnosis of double uterine cavity anomalies and concordance with laparoscopic and hysteroscopic diagnosis

Objectives

To determine whether three-dimensional (3D) ultrasound can replace combined hysteroscopic–laparoscopic role in differentiating bicornuate, septate and arcuate uterus.

Patient(s)

Seventy-two patients with history of infertility, recurrent abortions or preterm labor with hysterosalpingographic and/or two dimensional ultrasound diagnosis of double uterine cavity anomaly were included in this study.

Intervention(s)

Three-dimensional ultrasound (3D US) was done to all patients. Laparoscopy was done to differentiate bicornuate, septate and arcuate uterine anomalies. Simultaneous hysteroscopic metroplasty was done in patients with septate uteri.

Results

There was absolute concordance between 3D ultrasound and combined laparoscopic and hysteroscopic gold-standard in differentiation between bicornuate, septate and arcuate uteri in all our seventy two patients.

Conclusion(s)

3D US can differentiate septate, bicornuate and arcuate uteri and can eliminate the need for invasive laparoscopic diagnosis of these uterine anomalies.     

Revisit to congenital anomalies of the inner ear: The spectrum of aplastic/dysplastic labyrinthine malformations (ADLM). A new concept for classification

Aim

The aim of this work is to establish a new radiological classification system for the congenital anomalies of the inner ear depends on congenital gross morphological changes that occur in the bony labyrinth as seen with today’s multi-slice CT imaging technology.

Material and methods

This study was conducted on 26 congenitally deaf ear showing gross morphological changes of the bony labyrinth as seen with today multi-slice CT machines. The concept of ADLM radiological classification system depend on that both aplastic and dysplastic congenital anomalies of the bony labyrinth are linked. One or more component(s) of the labyrinth may be aplastic and other(s) may be dysplastic.

Results

The cochlea was the most common component of bony labyrinth prone to aplasia appeared in 7 ears (26.9%) followed by semicircular canals (19.23%). The vestibule was the most common component of the bony labyrinth resistant to aplasia and on the other hand it was the most common labyrinthine component that was prone to dysplasia.

Conclusion

ADLM is a numerical system that gives a total idea to the referring physician about the status of the bony labyrinth in a short simplified way. It could entail these anomalies with high degree of compliance.     

The value of 16-slice multidetector computed tomographic angiography in preoperative appraisal of vascular anatomy in potential living renal donors

Background

Comprehensive preoperative appraisal of potential living renal donors is the key for selecting a proper donor and a suitable kidney.

Objective

To prospectively assess the diagnostic value of 16-slice multidetector computed tomography (MDCT) in preoperative appraisal of vascular anatomy in potential living renal donors.

Materials and methods

Preoperative angiography using a 16-slice MDCT scanner was performed in 68 consecutive potential living renal donors. The MDCT angiography included unenhanced and contrast-enhanced multiphasic scans. The MDCT images were reviewed for the number and branching pattern of the renal arteries and for the number and presence of major or minor variants of the renal veins. The results were compared with the actual anatomy at the open donor nephrectomy as the diagnostic standard of reference.

Results

The sensitivity and the specificity of MDCT angiography for the detection of various anatomic variants of renal arteries as well as renal venous anomalies were 100%. The anatomic variants of renal arteries included accessory arteries (n = 7) and early arterial branching (n = 10). Whereas, the detected venous anomalies were of major category of the circumaortic left renal vein anomaly (n = 2). No minor renal venous anomaly was identified in any subject.

Conclusion

16-Slice MDCT angiography is highly accurate for preoperative assessment of diverse anomalies of the renal vascular anatomy in potential living renal donors; in consequence, it markedly affects the surgical planning.     

Imaging of the uterovaginal anomalies

Objective

To assess the role of different imaging modalities including ultrasonography, hysterosalpingogram, and magnetic resonance imaging in detection of variable Müllerian anomalies. Preoperative proper diagnosis data about Müllerian anomalies necessary for clear indications of how and when to operate.

Patients and methods

A retrospective MRI study of 34 patients was done in the period from February 2008 to February 2010, their age ranging from 3 months to 38 years (mean 24 years), with uterovaginal anomalies. Ultrasonography was performed for all cases; HSG was performed in 16 cases before MRI imaging.

Results

MRI is the most reliable method for evaluating uterovaginal anomalies, particularly in pediatrics and virgins. MRI is an accurate examination for identification and categorization of MDAs and should be carried out prior to any surgery, in this study MRI allowed correct diagnosis of 34 uterine anomalies (accuracy 100%) whereas US was correct in 30 out of 34 cases (accuracy 88%). HSG had a limited role as cannot be preformed for virgins, and cannot identify non-communicating horns in unicornuate cases.

Conclusion

MRI is the examination of choice in uterovaginal anomalies. Endovaginal ultrasound cannot be preformed for children or females who have never had sexual intercourse. TAUS have not proved completely reliable in Müllerian duct anomalies.     

Imaging of coronary artery anomalies using ECG-gated 64-row computed tomography angiography

Objective

To shed light on coronary artery anomalies among cardiac patients using ECG-gated 64-row MDCTA during assessment of coronary arteries.

Patients and methods

Study included 840 patients out of whom twenty-one patients have congenital coronary artery anomalies. Patients were examined using ECG gated 64-row MDCT; 80–100 ml contrast agent, followed by a 50 ml saline chaser injected at 5 ml/s, 350 ms gantry rotation time, 0.65 mm detector collimation, ECG tube current modulation and 100–120 kV. Post-processing was done on second workstation including 3D VR, MPR and CMPR images.

Results

Anomalies of the coronary arteries were diagnosed in twenty-one patients. The prevalence of congenital anomalies in this study was 2.5% and included: anomalous origin of right coronary artery in 4 cases (0.48%), anomalous origin of left circumflex artery in 3 cases (0.36%), myocardial bridging of LAD in 12 cases (1.4%) and coronary artery fistula in 2 cases (0.24%).

Conclusion

Coronary artery anomalies are not uncommon among cardiac patients. Myocardial bridging is the most common followed by anomalous origin and proximal course and lastly coronary artery fistula. 64-Row MDCTA is an excellent promising modality and should be the first non-invasive diagnostic tool to rule out such anomalies.     

Multidetector computed tomography (MDCT) angiography of thoracic aortic coarctation in pediatric patients: Pre-operative evaluation

Objective

The purpose of this study was to evaluate the reliability of 64-slice multi-detector computed tomographic (MDCT) angiography in pre-operative assessment of coarctation of thoracic aorta of pediatric age groups using 64 multislice CT scanner.

Materials and methods

Twenty four patients with clinical suspicion of coarctation of the thoracic aortic anomalies who underwent both Doppler echocardiography and MDCT angiography were included in the study. MDCT angiography findings were compared with both Doppler echocardiography and surgical results.

Results

The overall sensitivity of the MDCT angiography for diagnosis of the extra-cardiac aortic anomalies was 100% which was higher than that of Doppler echocardiography (92%). The overall sensitivity of MDCT angiography for the assessment of cardiac defects was 85% which was lower than that of Doppler echocardiography (100%).

Conclusion

We concluded that MDCT angiography with multiplanar and three dimensional techniques can be considered the modality of choice for pre-operative assessment of coarctation of the thoracic aorta in pediatric patients.     

Egyptian children with congenital sensorineural hearing loss candidates for cochlear implant: Is MRI evaluation necessary?

Objectives

Evaluating the value of MRI for assessing congenital anomalies of the inner ear in children with congenital sensorineural hearing loss (SNHL) before cochlear implantation.

Schizencephaly revisited

Purpose

In this paper, I will report the range of appearances of schizencephaly in children and fetuses by reviewing a 10-year experience from a single centre and detail classification systems for the different forms of schizencephaly. This will lead to re-assessment of possible aetiological and mechanistic causes of schizencephaly.

Methods

All cases of pediatric and fetal schizencephaly were located on the local database between 2007 and 2016 inclusive. The studies were reviewed for the presence, location and type of schizencephaly, as well as the state of the (cavum) septum pellucidum, the location of the fornices and the presence of other brain abnormalities.

Results

The review included 21 children and 11 fetuses with schizencephaly. Schizencephaly (type 1) was found in 9% of children but no fetuses, schizencephaly (type 2) was present in 67% of the pediatric cases and in 45% of fetuses, whilst schizencephaly (type 3) was present in approximately 24% of children and 55% of fetuses. Other brain abnormalities were found in 67% of children and 55% of fetuses.

Conclusion

I have proposed a new system for classifying schizencephaly that takes into account all definitions of the abnormality in the literature. Using that approach, I have described the appearances and associations of pediatric and fetal cases of schizencephaly from a single centre. Review of the current literature appears to favour an acquired destructive aetiology for most cases of schizencephaly, and I have proposed a mechanism to explain the cortical formation abnormalities found consistently in and around areas of schizencephaly.