Boyden’s nomenclature, which was based on postmortem specimens and published in 1955 prior to the advent of computed tomography (CT), is commonly used to describe the normal segmental bronchial anatomy and various abnormalities. However, several additional anomalies have been recognized since that time, and there is some confusion over the names used to describe these anomalies. Several congenital branching anomalies affecting the trachea, main bronchi, and intermediate bronchus have been reported, all of which can be recognized at chest CT but are often overlooked. These anomalies, which probably occur early in fetal life, can be either supernumerary, with defects occurring at 29–30 days gestation, or displaced, with defects occurring later. Tracheobronchial positional anomalies are often associated with other congenital abnormalities but may be isolated. They often are asymptomatic but can be responsible for pulmonary symptoms such as dyspnea, recurrent pneumonia, and hemoptysis. It is essential that th...

Objective: To determine the ultrasonographic characteristics of limited dorsal myeloschisis (LDM) at prenatal ultrasound (US) and to highlight the main features that may help differentiate LDM and myelomeningocele (MMC). Methods: In a tertiary reference center in fetal medicine, we prospectively collected the medical data and ultrasonographic characteristics of all patients referred for in utero prenatal repair of MMC between November 1, 2013 and April 30, 2015. Results: Among the 29 patients assessed, the diagnosis of MMC was revised in 7 cases. In 6 cases, the diagnosis of LDM was established. On US scan, LDM was characterized by a spinal saccular lesion with a thick peripheral lining in continuity with the adjacent skin. Within the saccular lesion, a thick hyperechoic well-delineated structure was present in continuity with the spinal cord. Cerebral structures were normal except for 2 cases showing a cisterna magna slightly decreased in size. In the remaining 22 cases MMC was confirmed, with cerebral anomalies present in 21/22 cases (95.5%). Conclusion: LDM is a form of closed dysraphism accessible to prenatal diagnosis by US that may mimic MMC. Considering the major difference in prognosis between these two entities, physicians should be aware of the existence and ultrasonographic characteristics of LDM.