Imaging description

Spina bifida properly refers to lack of fusion of the posterior bony element of the spinal canal. However, it is commonly confused with spinal dysraphisms, which are malformations of the spinal column and/or spinal cord across previous stages of development. The classification of spinal dysraphism takes into account the clinical, neuroradiological, and embryological features [1]. The neural placode is a segment of flattened, non-neurulated embryonic neural tissue [2]. It can be terminal or segmental, depending on its location with relation to the cord.

Clinically, spinal dysraphism can be categorized into open and closed varieties, depending on the location of the neural placode. In open spinal dysraphism (OSD), the placode is directly exposed to the environment and surrounded by partially epithelialized skin. In closed spinal dysraphism (CSD) the placode is covered with a full-thickness skin [3]. In 50% of patients with CSD, cutaneous birthmarks are also present. Therefore the term “occult spinal dysraphism” is not favored.