Spine ultrasound imaging in the newborn

International Consensus Statement on the Radiological Evaluation of Dysraphic Malformations of the Spine and Spinal Cord

Dysraphic malformations of the spine and spinal cord (DMSSC) represent a spectrum of common congenital anomalies typically (though not exclusively) affecting the lower spinal segments. These may be responsible for varying degrees of neurologic, orthopedic, and urologic morbidity. With advances in neuroimaging, it is now possible to better diagnose and evaluate these disorders both prenatally and postnatally. Neuroimaging, performed at the right time and with technique optimization, is integral in guiding clinical management. However, the terminology used to describe these lesions has become increasingly confusing, and there is a lack of consensus regarding the essential radiologic features and their clinical weighting. This variability in radiologic practice risks unstructured decision making and increases the likelihood of suboptimal, less informed clinical management. In this manuscript, the first of a series of consensus statements, we outline a standardized international consensus statement for the radiologic evaluation of children with suspected DMSSC derived from a critical review of the literature, and the collective clinical experience of a multinational group of experts. We provide recommendations for plain radiography, sonography, CT, and MR imaging in the evaluation of DMSSC with an emphasis on technique of imaging and imaging protocols.

Case report: Sacral agenesis in two boxer dogs: clinical presentation, diagnostic investigations, and outcome

Two boxer dogs from the same litter were presented at 3 months of age for urinary and fecal incontinence. Both dogs had an abnormal tail consisting of a small stump, an atonic anal sphincter, and absent perineal reflex and sensation. Neurological evaluation was indicative of a lesion of the cauda equina or sacral spinal cord. Radiology and CT scan of the spine displayed similar findings in the two dogs that were indicative of sacral agenesis. Indeed, they had 6 lumbar vertebrae followed by a lumbosacral transitional vertebra, lacking a complete spinous process, and a hypoplastic vertebra carrying 2 hypoplastic sacral transverse processes as the only remnant of the sacral bone. Caudal vertebrae were absent in one of the dogs. On MRI, one dog had a dural sac occupying the entire spinal canal and ending in a subfascial fat structure. In the other dog, the dural sac finished in an extracanalar, subfascial, well-defined cystic structure, communicating with the subarachnoid space, and consistent with a meningocele. Sacral agenesis-that is the partial or complete absence of the sacral bones-is a neural tube defect occasionally reported in humans with spina bifida occulta. Sacral agenesis has been described in human and veterinary medicine in association with conditions such as caudal regression syndrome, perosomus elumbis, and Currarino syndrome. These neural tube defects are caused by genetic and/or environmental factors. Despite thorough genetic investigation, no candidate variants in genes with known functional impact on bone development or sacral development could be found in the affected dogs. To the best of the authors' knowledge, this is the first report describing similar sacral agenesis in two related boxer dogs.

Unveiling the tale of the tail: an illustration of spinal dysraphisms

Spinal dysraphism is an umbrella term describing herniation of meninges or neural elements through defective neural arch. They can be broadly categorized into open and closed types. MRI is the investigation of choice to study neural abnormalities and to assess the severity of hydrocephalus and Chiari malformation. Knowledge of the embryology of these disorders is valuable in correctly identifying the type of dysraphism. The aim of surgery is untethering and dural reconstruction. Accurate depiction of the abnormal anatomy in cases of spinal dysraphism is of utmost importance for surgical management of these patients. MRI makes this possible due to its excellent soft tissue contrast resolution and multiplanar capability, allowing the radiologist to evaluate the intricate details in small pediatric spinal structures. Imaging enlightens the surgeons about the status of spinal cord and other associated abnormalities and helps detect re-tethering in operated cases. Besides, antenatal surgery to repair myelomeningoceles has made detection of open dysraphisms on fetal MRI and antenatal ultrasound critical. The purpose of this review is to describe the development of spine, illustrate the myriad imaging features of open and closed spinal dysraphisms, and enlist the reporting points the operating surgeon seeks from the radiologist.

Optimal Timing of Spinal Ultrasound Evaluations for Sacral Dimples in Neonates: Earlier May Not Be Better

OBJECTIVES

A spinal ultrasound (US) evaluation during the immediate postnatal period may have limited ability in evaluating filum thickness because of the spinal cord pulsation caused by a crowded subarachnoid space and the cerebrospinal fluid deficiency during this period. This study aimed to determine the optimal timing of spinal US to evaluate sacral dimples in neonates.

METHODS

This study included 585 neonates who had a clinically suspicious sacral dimple and underwent spinal US examinations between January 2015 and August 2017. Patients were classified into 1 of 2 groups based on whether measurements of all parameters were possible (group A) or not (group B). Neonatal and maternal clinical factors, including the antenatal history and US parameters, were compared between groups.

RESULTS

Group A included 443 patients, and group B included 82. Patients in group B were significantly younger (6.2 versus 31.0 days), had a younger corrective age (38.9 versus 42.5 weeks), and had a smaller body weight (3.1 versus 4.6 kg) than those in group A (all P < .005). However, no statistically significant differences were found in other patient or maternal factors (P > .05 for all). The pulsation of the conus medullaris and nerve roots of the cauda equina (14.6% versus 100%), thickening and echogenicity of the filum terminale (2.4% versus 100%), and the presence of a normal subarachnoid space (18.3% versus 100%) were significantly more difficult to detect in group B than in group A (all P < .001).

CONCLUSIONS

For an accurate evaluation, which can reduce unnecessary confusion and costs, spinal US can be delayed until neonates grow beyond 31 days, with a corrected age of older than 42.5 weeks and body weight of greater than 4.6 kg.

Occult spinal dysraphisms in newborns with skin markers: role of ultrasonography and magnetic resonance imaging

PURPOSE

The purpose of this paper is to investigate occult spinal dysraphisms (OSD) using lumbar ultrasonography (LUS) in newborns presenting with specific skin markers or sacrococcygeal dimple.

METHOD

From 2012 to 2015, we performed LUS in newborns with cutaneous stigmata and/or sacroccygeal dimple. Magnetic resonance imaging (MRI) was performed in all patients with abnormal ultrasound or features of neurological involvement in order to detect spinal lesions.

RESULTS

We prospectively evaluated 475 newborns who presented cutaneous stigmata performing LUS during their 4 weeks of life though 439 completed the study. All patients had a follow-up of almost 12 months. Of these, 39 presented abnormal ultrasonography and underwent MRI. In this group, spinal dysraphism was confirmed in 12 patients. When considering skin markers, dermal sinus correlated with higher risk of spinal cord lesions, on the other hand the presence of simple sacral dimple alone denoted a very low risk of occult spinal dysraphism. The simultaneous presence of more skin markers and/or the presence of lumbar ultrasonography abnormality regarding the level of the conus, pulsatility, and the position of the cord, thickness of the filum terminale, or the presence of an intratecal mass, lipoma, or dermal sinus tract indicated the necessity to perform MRI in order to detect spinal cord abnormalities because of higher risk of spinal lesions.

CONCLUSION

LUS in newborns with specific skin markers is a valid method to select patients in which MRI can be performed to detect OSD. The presence of a simple sacral dimple alone is a negligible marker for occult neural pathology while the presence of isolated dermal sinus or more than one cutaneous marker could be considered indicative of higher risk of spinal dysraphism.

Sonographic spinal imaging of normal anatomy, pathology and magnetic growing rods in children

The wide availability of ultrasound, along with its lack of ionizing radiation burden and need for sedation for most exams, often make sonography the first line in the imaging evaluation of children. The developing osseous anatomy of the spine in young infants provides a distinct window allowing for a detailed depiction of the spinal canal and its contents, which is not present in older children or adults. Here we review the clinical indications, sonographic technique, normal anatomy and pathology for imaging the lumbosacral spine in neonates and young infants. Additionally, we review the procedure for ultrasound assessment of the lengthening of magnetically controlled growing spinal rods, which allows orthopedists and radiologists to evaluate the effectiveness of distraction procedures of this hardware without the use of ionizing radiation.

Diagnostic Approach to Pediatric Spine Disorders

Understanding the developmental features of the pediatric spine and spinal cord, including embryologic steps and subsequent growth of the osteocartilaginous spine and contents is necessary for interpretation of the pathologic events that may affect the pediatric spine. MR imaging plays a crucial role in the diagnostic evaluation of patients suspected of harboring spinal abnormalities, whereas computed tomography and ultrasonography play a more limited, complementary role. This article discusses the embryologic and developmental anatomy features of the spine and spinal cord, together with some technical points and pitfalls, and the most common indications for pediatric spinal MR imaging.

Pediatric Spinal Ultrasound: Neonatal and Intraoperative Applications

The purpose of this article is to review the use of ultrasound as a screening tool for spinal diseases in neonates and infants and its intraoperative value in selected pediatric neurosurgical disorders. A review of spinal embryology followed by a description of common spinal diseases in neonates assessed with ultrasound is presented. Indications for spinal ultrasound in neonates, commonly identified conditions, and the importance of magnetic resonance imaging in selected cases are emphasized. Additionally, the use of ultrasound in selected neurosurgical spinal diseases in pediatric patients is presented with magnetic resonance imaging and intraoperative correlation. Technique, limitations, and pitfalls are discussed.

Congenital anomalies of lumbosacral spine: A pictorial review

Congenital malformations of the lumbosacral spine include spinal dysraphism and caudal anomalies. Most often, these malformations are discovered prenatally or in early infancy, but some are not diagnosed until late childhood or adulthood. The purpose of this pictorial review is to illustrate the multi-modality imaging characteristics in these complex anomalies and to provide a systematic radiological approach aiming at improving diagnostic accuracy.