ORGAN SYSTEM WISE ANOMALIES:
1.Thorax:
In the thorax, bilateral lung anomalies which are detected on sonography as cystic changes or echogenic lung (unilateral or bilateral) or effusions or associated everted diaphragm/ tracheal anomalies
1.a. Echogenic lungs:
a.i. Unilateral:
Congenital Cystic Adenomatoid Malformation-(CCAM): large-sized (> 10mm)-type-a, intermediate size (2-10mm) and Small-sized (<2mm)cystic transformation making it cystic or solid echogenic appearance on sonography which is usually lobar or segmental.
Sequestrum (Intra lobar/ extra lobar): commonly in the lower echogenic lung lobes/segments with a systemic vascular supply.
Congenital Diaphragmatic hernia(CDH): echogenic unilateral lung with mediastinal deviation towards the contralateral side, predominantly noted on the left side with visualization of stomach bubble in left hemithorax is a clue.
Bronchial Atresia: Segmental echogenic lung but very difficult to diagnose in fetal sonography unless a dilated ectatic bronchial segment noted within the lung.
a.ii. Bilateral:
Congenital High Airway Obstruction Syndrome (CHAOS)- due to tracheal or upper airway obstruction due to stenosis/ mucous plug.
Fetal MRI, how it gives an extra edge over the sonography is by detecting the lung volume in rendering volume calculation software. E.g.- In CDH, the volume of hypoplastic lung gives the neonatologist and pediatric surgeons better prognostication and plan for Ex Utero Intrapartum Treatment (EXIT) procedure.
2.CNS:
Most spinal dysraphism are confidently detected on sonography. Fetal MR gives an extra edge for detecting other comorbidity associated or anomalies associated with it. Fetal brain neoplasms and the cause of hydrocephalus can be better appreciated on MR.
In CNS developmental disorders include anencephaly-exencephaly sequence, corpus callosum dysgenesis, spinal dysraphism, intracranial & spinal tumors.
3. Geito-Urinary system:
In the development of ureters and genital system, primitive paramesonephric and mesonephric ducts are closely associated with fetal growth, most anomalies are associated with each other.
In kidneys, polycystic kidney diseases (ARPKDs, MCDK) are common. A posterior urethral valve with hydronephrosis is a common ureteric disorder.
In the genital system, obstructive vaginal septum or uterine anomalies, as well as ovarian cystic lesions, are common.
Miscellaneous-Placental imaging:
In placental imaging, intraplacental bleed, gestation trophoblastic diseases are common pathologies.
Other rare diseases like placental mesenchymal dysplasia and chorioangioma better appreciated on MR.
Placental adhesive diseases like placenta accreta, MR shows telltale signs of invasions and prognostication.
Though there are lots of anomalies associated with each other as chromosomal and genetic overlapping for the same molecular function.
Multiple congenital anomalies raise the suspicion of genetic and chromosomal foreplay, early detection and counseling help the better outcomes.