Prenatal assessment of the cardiovascular structure and brain development of fetuses with tetralogy of Fallot on fetal MRI / 中华放射学杂志

Objective:To explore the value of prenatal MRI in assessing the cardiovascular structure and brain development of fetuses with tetralogy of Fallot (TOF).Methods:From August 2011 to April 2021, 30 fetuses of TOF with gestational age (GA) 18-33 (25±3) weeks were retrospectively enrolled in Shanghai Children′s Medical Center, School of Medicine, Shanghai Jiao Tong University. Sixty normal fetuses were selected with matched GA of TOF fetuses as control group. In 30 fetuses with TOF, the GA of 17 fetuses were less than 25 weeks and of 13 fetuses were more than 25 weeks. The balanced fast field echo sequence MRI was performed to measure the diameter of the aortic arch isthmus (AoI), the main pulmonary artery (MPA) and the ratio was calculated (MPA/AoI). The size of ventricular septal defect (VSD) was measured in TOF group. The single-shot turbo spin echo sequence MRI was performed to measure fetal brain biparietal diameter (BBD), brain frontal-occipital length (BFOL), skull biparietal diameter (SBD), skull fronto-occipital diameter (SOD) and head circumference (HC). The Pearson analysis was used to evaluate the correlation of the above indicators with GA. The independent sample t test was used to compare the differences in various indicators between TOF and control groups in both GA≤25 and GA>25 weeks. Results:The sizes of VSD in TOF fetuses were (3.5±1.1) mm (GA≤25 weeks) and (4.4±0.6) mm (GA>25 weeks). The AoI, MPA, BBD, BFOL, SBD, SOD, HC were positively associated with GA (TOF group: r=0.80, 0.50, 0.92, 0.93, 0.91, 0.84, 0.91, MPA P=0.005, others all P<0.001; control group: r=0.90, 0.87, 0.96, 0.95, 0.93, 0.95, 0.96, all P<0.001). For fetuses with GA≤25 weeks, there were 17 fetuses in TOF group and 34 fetuses in control group, and the AoI in TOF group was larger than that in control group ( t=10.00, P<0.001), the MPA, MPA/AoI, BFOL were smaller than those in control group (all P<0.05). No statistical significant differences of BBD, SBD, SOD, HC were found between the groups (all P>0.05), For fetuses with GA>25, there were 13 fetuses in TOF group and 26 fetuses in control group, and the AoI in TOF group was larger than that in control group ( t=3.36, P=0.002) and MPA, MPA/AoI, BBD, BFOL, SOD, HC were smaller than those in control group (all P<0.05). No statistically significant difference of SBD was found between groups ( P=0.068). Conclusions:MRI is feasible to measure the cardiovascular structure and the brain development of fetuses with TOF. Fetuses with TOF have varying degrees of VSD, MPA stenosis and AoI dilation. An altered brain growth of fetuses with TOF appears in the second trimester of pregnancy.

MRI measurements for normal fetal aortic arch isthmus diameter and ductus arteriosus diameter between 20 to 36 gestational weeks / 中华围产医学杂志

Objective:To investigate the feasibility of MRI measurement for normal fetal aortic arch isthmus diameter and ductus arteriosus diameter between 20 to 36 weeks of gestation and analyze its relationship with gestational age.Methods:This retrospective study enrolled 257 pregnant women with an unclear fetal four-chamber view in prenatal ultrasonography, whose following fetal MRI examination results showed no structural cardiac abnormalities, in Shanghai Children's Medical Center Affiliated to the Medical College of Shanghai Jiaotong University from June 2018 to June 2020. Postnatal echocardiography confirmed cardiac structures were normal in all cases. MRI images were reviewed to measure the diameter of the aortic arch isthmus, defined as the aortic arch isthmus's central diameter, in the transverse section of the aortic arch in steady-state free precession sequence imaging and the diameter of ductus arteriosus near the descending aorta. The average values were calculated after repeating each measurement three times. The 5th, 50th and 95th percentiles and their 95% CI of the aortic arch isthmus diameter and the ductus arteriosus diameter corresponding to different gestational age and the mean value and its 95% CI of the ratio of the aortic arch isthmus diameter to the ductus arteriosus diameter were calculated. Pearson correlation analysis and regression analysis were used to evaluate the relationship of the aortic arch isthmus diameter and the ductus arteriosus diameter with gestational age. Results:The regression equation between the aortic arch isthmus diameter and gestational age was as follows: the aortic arch isthmus diameter (mm) =-2.85+0.22×gestational age (weeks), and there was a positive linear correlation between them ( R2=0.737, P<0.001). The 50th percentile of the aortic arch isthmus diameter was 1.8-3.5 mm at 20-28 weeks and 3.5-5.0 mm at 28-36 weeks. The regression equation between the diameter of ductus arteriosus and gestational age was as follows: the diameter of ductus arteriosus (mm) =-2.17+0.19×gestational age (weeks), and a positive linear correlation between them was revealed ( R2=0.606, P<0.001). The 50th percentile of the diameter of ductus arteriosus was 2.0-3.5 mm at 20-28 weeks and 3.2-4.8 mm at 28-36 weeks. The 95% CI for the ratios of the aortic arch isthmus diameter to the ductus arteriosus diameter at 20, 22, 24, 26, 28, 30, 32, 34 and 36 weeks of gestation were 0.8-1.1, 0.8-1.0, 0.8-1.0, 0.8-1.3, 0.8-1.5, 0.9-1.5, 0.9-1.7, 0.9-1.1 and 1.0-1.3, respectively, and were all close to 1. Conclusions:It is feasible to measure fetal aortic arch isthmus diameter and ductus arteriosus diameter at 20-36 weeks of gestation in MRI, and both measurements have a linear correlation with gestational age.

Clinical value of prenatal MRI in the diagnosis and differential diagnosis of fetal bronchopulmonary sequestration / 中华妇产科杂志

Objective To investigate the clinical value of prenatal MRI in the diagnosis and differential diagnosis of congenital bronchopulmonary sequestration (BPS). Methods From January 2009 to December 2014, 16 fetuses with BPS were diagnosed by fetal MRI in Huzhou Maternity and Child Care Hospital and Shanghai Children′s Medical Center Affiliated to Shanghai Jiaotong University School of Medicine. The clinical data of these cases were analyzed retrospectively. All were singleton pregnancy, and MRI was carried out within 24-48 hours after routine prenatal ultrasound. All the neonates underwent postnatal enhanced CT scan or surgical biopsy after birth, and the results were compared to prenatal MRI diagnosis. Results (1)With prenatal MRI, 16 cases were diagnosed BPS. The lesions located in left lung in 10 cases, and right lung in 6 cases. As the scope of the lesion, 3 cases located in the whole left lung, 6 cases limited to the left lower lobe, and 1 case was subdiaphragmatic on the left side. 2 cases located in the whole right lung and 4 cases limited to the right lower lobe. One case complicated oligoamnios, and one had pleural effusion. Supplying vessels could be found in 14 cases.(2)When the postnatal results were compared with prenatal MRI, 15 cases were comfirmed as BPS (15/16), including 10 intralobar cases 5 extralobar cases. One that was diagnosed as BPS by prenatal MRI was confirmed to be congenital cystic adenomatoid malformation (CCAM) by pathology. The accuracy of prenatal MRI diagnosis of BPS was 15/16. Prenatal ultrasound missed one case and misdiagnosed two cases, as one was mistakened as CCAM and the other as cystic teratoma. Conclusion Prenatal MRI has good clinical value in the diagnosis and differential diagnosis of fetal BPS.

The image analysis of prenatal ultrasound and MRI of fetal right congenital diaphragmatic hernia / 中华医学超声杂志（电子版）

Objective To summarize the image features of prenatal ultrasound and MRI of fetal right congenital diaphragmatic hernia (CDH). Methods Between June 2007 and December 2014, eight fetuses with suspicious right pleural abnormalities diagnosed by conventional prenatal ultrasound received MRI examination within 24 to 48 hours after ultrasonography at Shanghai Children′s Medical Center. The imaging sequences included steady-state free-precession (SSFP) sequence, single-shot turbo spin echo (SSTSE) sequence and T1-weighted imaging (T1WI) sequence. Prenatal ultrasound and MRI findings were compared with postnatal imaging diagnoses, surgery or autopsy. The image features of prenatal ultrasound and MRI of fetal right CDH were analyzed. Results Among the eight cases of fetal prenatal ultrasound, 7 cases presented right pleural abnormal heterogeneous echo, 1 case showed right pleural effusion. Fetal prenatal MRI showed seven cases of right-sided pleural abnormalities, included a portion of the liver in 2 cases, a portion of the bowel in 2 cases, a portion of the liver and the bowel in 3 cases. One case was with bilateral pleural abnormalities, the liver and the bowel in right thoracic cavity, a portion of the bowel in left thoracic cavity. Prenatal ultrasound and MRI findings were compared with postnatal upper gastrointestinal tract barium contrast, enhanced chest CT, surgery or autopsy. Prenatal ultrasound correctly diagnosed 4 cases of fetal right CHD, misdiagnosed right CHD as right pleural mass in 2 cases, missed 1 case of right CHD, and misdiagnosed 1 case of bilateral CHD as right CHD. MRI correctly diagnosed 7 cases of fetal right CHD and 1 case of bilateral CHD. Conclusions Prenatal ultrasound couldn′t identify the detailed contents herniated into the fetal thoracic cavity of right CDH, especially when the liver herniated into the fetal thoracic cavity. However, prenatal MRI could clearly show the hernia contents in the fetal thoracic cavity, and make the correct diagnosis of fetal right CHD as well as the hernia contents in the fetal thoracic cavity. Both SSFSE and T1WI sequences can distinguish detailed contents herniated into the thoracic cavity.

MRI findings of tuberous sclerosis complex combined with cardiac rhabdomyomas in fetuses and infants / 中华放射学杂志

Objective To improve the understanding,the incidence and imaging findings of tuberous sclerosis complex (TSC) combined with cardiac rhabdomyomas (CRs) in fetuses and infants.Methods The imaging findings of 9 infants with TSC combined with CRs and 4 fetuses with TSC combined with CRs from our hospital between June,2006 and November,2013 were retrospectively reviewed.Results The brain MRI of 9 with TSC combined with CRs showed bilateral subependy-mal nodules,subcortical white matter and cortical tubers.Subependymal nodules were isointense or hypointense on spin-echo T1WI and hypointense or hyperintense on spin-echo T2WI.Subcortical white matter and cortical tubers were hypointense or hyperintense on T1WI and hypointense or hyperintense on T2WI.There was varying contrast enhancement.Three of 9 infants presented single cardiac tumor and 6 of 9 infants presented multiply cardiac lesions.CRs on contrast cardiac MRI showed round solid masses in ventricular septums,ventricular outflow tract,ventricle or atrial free walls.The masses were isointense relative to the cardiac muscles on T1WI,T2WI and B-TFE sequence.There was varying contrast enhancement.Four fetuses with TSC on ultrafast MRI showed bilateral multiply subependymal nodules,the nodules were isointense or hyperintense on TFE T1WI and isointense or hypointense signals on SSTSE or B-FFE sequence,Four fetuses with CRs showed isointense to hyperintense solid masses in ventricular septums on ultrafast MRI,ventricle or atrial free walls on B-FFE sequence and SSTSE sequence images.Conclusions TSC in infant and fetus is a kind of neurocutaneous syndrome,usually combines with CRs.Fetal ultrafast and routine MRI is a useful method to make a definite diagnosis for cranial and cardiac lesions.The development of MRI might improve the timeliness and accuracy of the assessment for this disease.

MRI assessment of fetal autosomal recessive polycystic kidney disease / 中华放射学杂志

Objective To explore the value of MRI on fetal autosomal recessive polycystic kidney disease (ARPKD).Methods Sixteen pregnant women,aged from 28 to 38 years (average 30 years) and with gestation age from 22 to 36 weeks (average 25 weeks) underwent MR scanning with a 1.5 T MR unit within 24 to 48 hours after ultrasound examinations.The imaging sequences included steady-state free-precession (SSFP) sequence,single-shot turbo spin echo (SSTSE) sequence and T1-weighted fast imaging sequence.Prenatal US and MR imaging findings were compared with autopsy or pathological results.Results A total of 16 cases of ARPKD showed bilateral markedly enlarged kidneys and diffuse high signal small cysts in renal medulla on SSTSE sequence.Among the 16 cases,11 cases were with oligohydramnios,1 1 cases were with pulmonary hypoplasia,and 6 cases were with hepatic fibrosis.Eleven cases of pulmonary hypoplasia and 6 cases of hepatic fibrosis were all missed by US.For the diagnosis of the renal anomalies,US missed one case.MRI diagnosis was correct in all these cases.Conclusions MRI shows great advantages on the diagnosis of fetal ARPKD,and it is not affected by the amount of amniotic fluid.It can be used to evaluate kidney and lung abnormalities accurately.

Diagnosis of horseshoe lung with multi-slice helical CT / 中华放射学杂志

Objective To study the multi-slice helical CT (MSCT) features of horseshoe lung and to improve its diagnostic ability. Methods The clinical and imaging data were retrospectively reviewed in 5 patients. All of them underwent plain MSCT scan, and 4 patients also had enhanced MSCT scan and threedimensional reconstruction. Results In horseshoe lung, the basal segments of the right and left lungs were fused together by a isthmus of pulmonary parenchyma, across the midline behind the pericardium and before the esophagus, descending aorta and spine. All patients were companied with bronchopulmonary dysplasia,anomalous origin of the central bronchi, anomalous arterial supply. Anomalous pulmonary venous return to inferior vena cava and congenital cardiovascular malformations were also found in 4 cases. Conclusion MSCT and three-dimensional reconstruction are valuable for identification of horseshoe lung.

Diagnosis of fetal neural tube defects by MRI / 中华放射学杂志

Objective To explore the diagnostic value of MRI on fetal neural tube defects.Methods Ten pregnant women,aged from 25 to 35 years(average 28 years)and with gestation from 20-39 weeks(average 33 weeks)were studied with a 1.5 T superconductive MR unit within 24 to 48 hours after ultrasound(US)studies.The imaging protocol included fast-imaging employing steady-state acquisition,single-shot FSE and T_1-weighted fast inversion recovery motion insensitive sequences in the axial,frontal,and sagittal planes relative to the fetal brain,thorax,abdomen,and spines.Prenatal US and MRI findings were compared with postnatal MRI diagnoses(3 fetuses)or autopsy(7 fetuses).Results Ten pregnant women(9 with a single fetus and 1 with twin fetuses)were examined.For all cases,the diagnoses established by MRI were correct when compared with postnatal diagnosis or autopsy.In 7 cases,US and MRI findings were in complete agreement with postnatal diagnoses.US missed the diagnosis in 1 case and misdiagnosed in 2 cases.Ten neural tube defects in this study included anencephaly(1 case),exencephaly (1 case),meningoencephalocele associated with amniotic band sequence(1 case),meningocele(1 case),thoracic myelomeningocele(1 case),lumbar spinal bifida(1 case),sacroiliac myelomeningocele(2 cases),sacroiliac large cystic spinal meningocele(1 case),sacroiliac spinal bifida(1 case).Conclusions Prenatal MRI is effective in the assessment of fetal neural tube defects.It can exactly discriminate herniated contents and locate the spinal lesion level.

MRI diagnosis of fetal congenital diaphragmatic hernia / 中华放射学杂志

Objective To explore the diagnostic value of MRI on fetal congenital diaphragmatic hernia(CDH).Methods Fourteen pregnant women with gestation from 16 to 39 weeks were studied with a 1.5 T superconductive MR unit within 24 to 48 hours after ultrasound studies.Fast-imaging employing steady-state acquisition(FIESTA),single-shot fast spin echo(SSFSE)and T_1-weighted fast inversion recovery motion insensitive(FIRM)sequences were employed on the axial,coronal and sagittal planes of the fetal brain,thorax and abdomen,especially the thorax.Prenatal US and MR imaging findings were compared with postnatal diagnoses(13 fetuses)or autopsy(1 fetus).US,MR imaging and surgery were used for postnatal evaluation.Results Fourteen pregnant women(12 with a single fetus and 2 with twin fetuses)were studied.There were 12 fetuses(in 2 cases,being one of twins)with a left-sided and 2 with right-sided diaphragmatic hernias.For all cases,the prenatal MRI diagnosis Was correct when compared with postnatal diagnosis or autopsy.Two CDHs were missed and 2 were misdiagnosed by US.Intrathoracic herniated organs in 12 left CDH included the colon(n=1),the stomach(n=1),the bewel(n=5),or both the stomach and bowel(n=5).Intrathoracic herniated organs in 2 right CDH included the bowel(n=1),or the bowel and the right lobe of the liver(n=1).Conclusion Prenatal MRI is effective in the assessment of fetal congenital diaphragmatic hernia.

Diagnosis of fetal congenital limb deformities by MRI / 中华放射学杂志

Objective To explore the diagnostic value of MRI on fetal congenital limb deformities.Methods Sixteen pregnant women,aged from 22 to 40 years (average 29 years) and with gestation from 22 to 39 weeks (average 29 weeks) were studied with a 1.5 T superconductive MR unit within 24 to 48 hours after ultrasound studies. Acquisitions consisted of coronal, sagittal, and axial slices relative to the fetal brain, spine, thorax, abdomen, especially limbs using 2D FIESTA sequences. Prenatal US and MR imaging findings were compared with postnatal diagnoses (4 fetuses) or autopsy (12 pregnant women,13 fetuses). Postnatal evaluation included US, MR imaging, computed tomography, and physical examination. Results Of the sixteen pregnant women (15 with a single fetus and 1 with twin fetuses) ,17 fetuses were found. Those limb deformities of sixteen pregnant women included congenital both upper extremities amelia (1 case), sirenomelia sequence (1 case), micmmelia (5 cases, 1 of which were twins),bilateral clenched hands (2 cases), right pelydactyly (1 case), simple right ectrodactyly (1 case), right dactylolysis(1 case), simple club foot (2 cases), hydrocele spinalis with club foot (2 cases), 1 of the 2 cases with bilateral clinodactyly. In 14 of 16 cases, the diagnoses established by MR imaging were correct when compared with postnatal diagnosis, and prenatal MR diagnosis was inaccurate in 2 cases. Conclusion Prenatal MRI is effective in the assessment of congenital limb deformities of fetuses, it can yield information additional to that obtained with US, and further correct US diagnosis.