Prenatal Imaging Diagnosis Research Articles

Limitations of fetal ultrasonography and magnetic resonance imaging in prenatal diagnosis of congenital cerebral arteriovenous malformations with hemorrhagic onset

A fetus at 30 gestational weeks was observed on fetal ultrasonography to have a dilated right lateral ventricle. After delivery, the entity was diagnosed as a prenatal intracerebral hemorrhage (ICH) due to a ruptured arteriovenous malformation (AVM). Ultrasonography and MRI examinations performed before birth indicated a cerebral aneurysm in the territory of the right middle cerebral artery. However, digital subtraction angiography revealed an intracystic hemorrhage due to a ruptured cerebral AVM. Arteriovenous malformations in children are rare, difficult to diagnose, and result in permanent sequelae after delayed treatment. Patient prognosis depends on early and accurate diagnosis and intervention. Outcomes can be improved if an AVM in a child is detected at the onset of ICH for young infants in the prenatal or early postnatal periods. Early AVM diagnosis is limited to fetal ultrasonography and MRI, and special consideration through invasive examination including neonatal digital subtraction angiography is urged unless a correct and clear diagnosis is made at an early stage. Prenatal ICH due to an AVM is rare. The authors discuss their observations and findings.

Prenatal diagnosis of ‘isolated’ Dandy–Walker malformation: imaging findings and prenatal counselling

The purpose of this article is to improve prenatal imaging diagnosis and counselling for cases of 'isolated' Dandy-Walker malformation (DWM) in the light of recent literature, which has demonstrated a potential good clinical and intellectual outcome of fetuses presenting with DWM characterised by partial vermian agenesis (identification of two fissures and three lobes) and absence of associated anatomical anomalies. This is a retrospective observational study of six consecutive prenatal cystic posterior fossa malformations, diagnosed as DWM, encountered in a national reference centre for posterior fossa malformations over a 2-year period. In all cases, DWM was diagnosed as isolated (without any associated central nervous system or extra-central nervous system malformations and normal standard karyotype). Despite good-quality imaging, including fetal magnetic resonance imaging (MRI), prenatal analysis of the vermis was impossible because of limited identification of fissuration and lobulation. In three cases, a cytogenetic anomaly was found, including 6p subtelomeric deletion (n = 2) and partial 4 qter deletion associated with partial 7p trisomy (n = 1). One fetus with 6p deletion was terminated. In four of the five postnatal cases, MRI confirmed the diagnosis of DWM but provided only limited information for vermian analysis. In one case, postnatal MRI showed a large Blake's pouch cyst with rotated but complete vermis associated with a marked mass effect on the distal part of the tentorium. Of the four babies born with postnatal diagnosis of DWM, all required ventriculoperitoneal shunting because of early postnatal hydrocephalus. When fetal MRI is necessary to exclude additional cerebral lesions in the diagnosis of DWM, we highlight the inaccuracy of magnetic resonance for anatomical analysis of the vermis. We also emphasise the potential high incidence of subtelomeric anomalies in isolated DWM, especially 6p deletion. In the postnatal period, paediatricians should look for postnatal hydrocephalus even if the ventricular size is normal or slightly dilated on prenatal imaging.

Three‐dimensional high‐definition flow imaging in prenatal diagnosis of a true umbilical cord knot

Three‐dimensional high‐definition flow imaging in prenatal diagnosis of a true umbilical cord knot

Ultrasonography and magnetic resonance imaging in prenatal diagnosis of tumour of the foetal head and neck

Foetal tumours are relatively rare; prenatal diagnosis enables additional diagnostics, and thus the decision on the continuation of pregnancy and planning of delivery. The paper presents prenatal ultrasound diagnostics of foetal head tumour with additionally analyzed magnetic resonance imaging (MRI). On ultrasound imaging, in a 27-year-old nullipara, a tumour of the foetal head was suspected at the 22nd gestational week. By consultative ultrasound, a 45 x 41 x 50 mm echogenic soft tissue tumour with hypoechogenic areas was confirmed, which originated from the left side of the skull spreading towards the neck on the left behind the ear. On colour Doppler no vascularisation was seen within the tumour but several vessels were seen along the border-line and on the surface. The scan showed no associated abnormalities. Karyotype was 46, XY. MRI scan using triplanar SSFSE and HASTE sequences was done at 26 weeks and confirmed a 84 x 45 x 71 mm tumour originating from the scalp, spreading along the endocranium over the entire surface of the fronto-temporal sqama and left parietal bone. The tumour did not disturb the integrity of the internal tabula, and did not spread intracranially. Based on these findings, the diagnosis of haemangioma was made. At 38 weeks gestation, a 3810 g male infant was delivered by Caesarean section. A bluish, well-defined, non-pulsatile tumour arising from the left frontoparietal region was seen, thus confirming the diagnosis of haemangioma. MRI improved delineation of the tumour facilitating better planning of postnatal management and mode of delivery, with the information on the postnatal course and prognosis. In the prenatal period, MRI following an ultrasound diagnosed foetal tumour, is an additional part of diagnostic examinations, and is not contraindicated during pregnancy.

Clinical significances of magnetic resonance imaging in prenatal diagnosis of vasa previa in a woman with bilobed placentas

We report a case of a pregnant woman diagnosed as having vasa previa by magnetic resonance imaging (MRI). A parous woman was referred to our hospital at 31 weeks of gestation due to suspicion of placenta previa. Transvaginal ultrasound examination together with the Doppler techniques showed a fetal vessel on a lesion of low and high mixed echogenecities over the internal os, but could not confirm whether it was placental tissue or not. MRI demonstrated that it was not placenta but a hemorrhage between bilobed placentas and that the vessel was running over the internal os freely from the placenta. At 34 weeks of gestation, emergency cesarean section was performed due to increasing vaginal bleeding. MRI should be useful in the diagnosis of vasa previa when the relation between the position of the placenta and that of suspicious vessels cannot be adequately evaluated by ultrasound.

Role of MR Imaging in Prenatal Diagnosis of Pregnancies at Risk for Joubert Syndrome and Related Cerebellar Disorders

JSRD are rare autosomal recessive brain malformations. We hypothesized that MR imaging can assess fetuses at risk for JSRD and might influence their diagnoses. We prospectively performed cranial MR imaging for 12 fetuses (mean GA, 23 weeks; SD, 3.7) at 25% recurrence risk for JSRD. We correlated prenatal MR imaging findings with postnatal MR imaging and clinical outcome. Retrospectively, we compared posterior fossa measurements of the cases with those of 24 age-matched fetuses with proved normal brain MR imaging. Institutional review board approval and consents were obtained. Statistical methods included a t test and ANCOVA tests. Fetal MR imaging correctly diagnosed 3 cases at 22, 28, and 29 weeks of gestation as JSRD, and 9 cases as normal. In JSRD-affected fetuses, prenatal MR imaging detected narrow pontomesencephalic junction (isthmus) with deepening of the interpeduncular fossa and thick horizontally placed superior cerebellar peduncles (MTS), deformed anteriorly convex floor of the fourth ventricle, and midline cerebellar cleft in place of the hypoplastic vermis. Measurements on axial fetal MR imaging at pontomesencephalic junction, ratio of AP diameters of interpeduncular fossa to midbrain/isthmus, and ratio of the AP to transverse diameters of the fourth ventricle were significantly higher in JSRD-affected fetuses than in nonaffected cases and the control group. MR imaging can diagnose JSRD in at-risk pregnancies by detecting posterior fossa signs. Measurements at the pontomesencephalic junction may enhance fetal MR imaging accuracy in diagnosing JSRD.

Contribution of ultrafast magnetic resonance imaging in prenatal diagnosis of sonographically undetected cerebral tuberous sclerosis associated with cardiac rhabdomyomas

Contribution of ultrafast magnetic resonance imaging in prenatal diagnosis of sonographically undetected cerebral tuberous sclerosis associated with cardiac rhabdomyomas

Magnetic Resonance Imaging in Prenatal Diagnosis of Dacryocystocele

The presence of cystic dilation of the lacrimal drainage system (dacryocystocele) in the fetus must be differentiated from less benign paraocular masses. Three cases of dacryocystocele studied during fetal life by ultrasound and magnetic resonance (MR) imaging are reported. The accuracy of prenatal MR imaging facilitated a definite diagnosis depicting the characteristic triad of dacryocystocele: paraocular cystic mass in the medial canthus region, nasolacrimal duct enlargement, and intranasal cyst.

La pathologie du tube digestif fœtal, apport de l’imagerie dans le diagnostic anténatal

Foetal anomalies of the digestive tract are numerous and dominated by malformations, the prognosis of which may be severe. Antenatal diagnosis of these anomalies allows a better management of neonates. It is known since about 20 years, a major development because of the progress realized in the field of foetal imaging. Ultrasonography, which is the best imaging modality, can be joined by MRI if necessary. The objective of this study is to evaluate the contribution of imaging in prenatal diagnosis of digestive anomalies, throughout a review of literature.

1. 出生前画像診断の進歩(A5 小児脳神経外科の現状と今後の展望)

1. 出生前画像診断の進歩(A5 小児脳神経外科の現状と今後の展望)

Advances in Imaging in Prenatal Diagnosis and Fetal Therapy

Technological advances in ultrasound have contributed to improvements in prenatal diagnosis. Transvaginal scanning and harmonic imaging have allowed better resolution and improved structural characterisation. Doppler techniques have further been improved, which allow accurate flow studies of vessels in the placenta and fetus. These have contributed much to the management of intrauterine growth restriction, fetal anaemia and twin-twin transfusion syndrome (TTTS). Three-dimensional sonography and magnetic resonance imaging ultrafast sequences are useful adjuncts to conventional 2-dimensional sonography, increasing the confidence and diagnostic accuracy of prenatal diagnosis. Fetal therapy has seen major advances in recent years as well, secondary to improvements in endoscopic instruments and surgical techniques. Selective Nd:YAG laser photocoagulation of communicating vessels and cord occlusion have been used to treat complications of monochorionic twins like TTTS and twin-reversed arterial perfusion sequence.

P098: Magnetic resonance imaging in prenatal diagnosis

P098: Magnetic resonance imaging in prenatal diagnosis

Initial experience using magnetic resonance imaging in prenatal diagnosis of osteogenesis imperfecta type II: A case report

We report a fetus with osteogenesis imperfecta (OI) first diagnosed by ultrasound in routine prenatal examination and further evaluated by magnetic resonance imaging (MRI). Fetal MRI was undertaken with a 1.5-T magnet using a body-phased array coil and an ultrafast imaging technique, half-Fourier single-shot turbo spin-echo (HASTE). Radiological examination shortly after birth and postmortem examination confirmed the prenatal diagnosis. In this case, fetal MRI provided excellent spatial and tissue resolution with multiplanar display. It revealed additional diagnostic information and improved imaging conspicuity. MRI complemented sonography for further differentiating clinical and sonographic findings.

Fetal magnetic resonance imaging in prenatal diagnosis of central nervous system abnormalities: 3-year experience

Objective: To evaluate the comparative merits of ultrasound and fetal magnetic resonance imaging (MRI) in the correct antenatal diagnosis of suspected central nervous system abnormalities.Methods:A retrospective review of 27 consecutive pregnancies referred for fetal MRI for suspected central nervous system abnormalities between July 1998 and July 2001. Women were referred for the MRI examinationwhen further anatomical and/or pathological clarification of the ultrasound scan findings was needed. Antenatal ultrasound scan and MRI were reviewed in relation to the findings on postpartum investigations.Results: Data were complete for 26 pregnancies. The median gestational age at the time of the ultrasound examination was 26 weeks (95% CI 24 weeks 2 days to 28 weeks 1 day). The median gestationalage at the time of magnetic resonance imaging was 27 weeks' gestation (95% CI 26 weeks 1 day to 29 weeks 2 days). Eight fetuses had associated skeletal, renal and/or cardiac abnormalities previously notedon ultrasound examination. MRI confirmed the ultrasound diagnosis in 15/26 cases (58%). It changed the diagnosis to the correct one in 7/26 (27%) and misdiagnosed four cases (15%). Three of the four casesthat were misdiagnosed on MRI occurred in the first 18 months of our 36-month experience.Conclusion: Ultrasound remains the primary imaging modality for prenatal diagnosis. Fetal MRI appearsto be a useful adjunct to ultrasound to confirm or exclude certain abnormalities; this will consequently help in the counselling of parents and assist in planning further management. However, like any imagingtechnique, the sensitivity and specificity of the test are likely to improve with experience.

Magnetic resonance imaging in prenatal diagnosis.

Ultrasound is the screening modality of choice for fetal imaging. However, when additional information regarding fetal anatomy or pathology is needed, fast magnetic resonance (MR) imaging is being used increasingly as a correlative imaging modality because it uses no ionizing radiation, provides excellent soft tissue contrast, has multiple planes for reconstruction, and a large field of view. Sonographic examination of the fetus is still important for selecting the appropriate fetuses for MR examination and to guide the protocol of the examination. Performance of high quality sonographic and MR examinations, as well as interpretation by individuals familiar with prenatal diagnosis, are important factors for optimal parental counseling. Magnetic resonance imaging frequently adds additional information beyond that available with ultrasound. This information commonly changes patient counseling, and at times patient management.

The role of magnetic resonance imaging in prenatal diagnosis of fetal anomalies

Magnetic resonance imaging (MR) has become a useful adjuvant in evaluating fetal structural anomalies when ultrasound (US) is equivocal. It has a significant promise in confirming a US suspected abnormality and providing new information that was previously not available. The first studies on prenatal MR were hindered by fetal motion and long acquisition times. This degraded imaging and, therefore, maternal or fetal sedation was needed. Since fast and ultrafast MR with scan times of <1 s have become available, the amount of motion artifacts is decreased and sedation is no longer needed. MR has proved to be especially beneficial in detecting CNS anomalies. Agenesis of the corpus callosum, migration abnormalities and abnormalities of the posterior fossa are better seen on MR. Masses in the fetal neck and thorax can be identified on MR, as some abdominal anomalies. However, the fetal skeletal is difficult to visualize with MR. In the future, it is most likely that real time MR will become clinically available which would improve MR imaging even more.

Fetal imaging in prenatal diagnosis.

Fetal imaging in prenatal diagnosis.

Magnetic resonance imaging in prenatal diagnosis.

Magnetic resonance imaging in prenatal diagnosis.