neonatalSpine.

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AIUM Practice Parameter for the Performance of an

Ultrasound Examination
of the Neonatal Spine
Parameter developed in collaboration with the American College of Radiology,
the Society for Pediatric Radiology, and the Society of Radiologists in Ultrasound.

2011 by the American Institute of Ultrasound in Medicine

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The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use
of ultrasound in medicine through professional and public education,
research, development of parameters, and accreditation. To promote
this mission, the AIUM is pleased to publish, in conjunction with the
American College of Radiology (ACR), the Society for Pediatric
Radiology (SPR), and the Society of Radiologists in Ultrasound (SRU),
this AIUM Practice Parameter for the Performance of an Ultrasound
Examination of the Neonatal Spine. We are indebted to the many
volunteers who contributed their time, knowledge, and energy to
bringing this document to completion.
The AIUM represents the entire range of clinical and basic science
interests in medical diagnostic ultrasound, and, with hundreds of
volunteers, the AIUM has promoted the safe and effective use of ultrasound in clinical medicine for more than 50 years. This document and
others like it will continue to advance this mission.
Practice parameters of the AIUM are intended to provide the medical
ultrasound community with parameters for the performance and
recording of high-quality ultrasound examinations. The parameters
reflect what the AIUM considers the minimum criteria for a complete
examination in each area but are not intended to establish a legal standard of care. AIUM-accredited practices are expected to generally follow the parameters with recognition that deviations from these parameters will be needed in some cases, depending on patient needs and
available equipment. Practices are encouraged to go beyond the
parameters to provide additional service and information as needed.

14750 Sweitzer Ln, Suite 100

Laurel, MD 20707-5906 USA
800-638-5352 301-498-4100
www.aium.org

2011 American Institute of Ultrasound in Medicine

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2011AIUM PRACTICE PARAMETERNeonatal Spine

I. Introduction
The clinical aspects contained in specific sections of this parameter (Introduction,
Indications/Contraindications, Specifications of the Examination, and Equipment
Specifications) were developed collaboratively by the American Institute of Ultrasound in
Medicine (AIUM), the American College of Radiology (ACR), the Society for Pediatric
Radiology (SPR), and the Society of Radiologists in Ultrasound (SRU). Recommendations
for physician requirements, written request for the examination, procedure documentation,
and quality control vary between the 4 organizations and are addressed by each separately.
This parameter has been developed to assist practitioners performing a sonographic examination of the neonatal and infant spine. In some cases, an additional or specialized examination
may be necessary. While it is not possible to detect every abnormality, following this parameter will maximize the detection of abnormalities of the infant spine. Sonographic examination
of the pediatric spinal canal is accomplished by scanning through the normally incompletely
ossified posterior elements. Therefore, it is most successful in the newborn period and in early
infancy. In infants older than 6 months, the examination can be very limited, although the level
of termination of the cord may be identified.
In experienced hands, ultrasound imaging of the infant spine has been shown to be an accurate
and cost-effective examination that is comparable to magnetic resonance imaging for evaluating congenital or acquired abnormalities in the neonate and young infant.
1

II. Qualifications and Responsibilities of Personnel

See www.aium.org for AIUM Official Statements including Standards and Guidelines for the
Accreditation of Ultrasound Practices and relevant Physician Training Guidelines.

III. Indications/Contraindications
A. Indications
The indications for sonography of the neonatal spinal canal and its contents include but are
not limited to18:
1. Lumbosacral stigmata known to be associated with spinal dysraphism, including but
not limited to:
a.

Midline or paramedian masses;

b. Skin discolorations;
c.

Skin tags;

d. Hair tufts;
e.

Hemangiomas;

f.

Pinpoint midline dimples; and

g.

Paramedian deep dimples;

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2. The spectrum of caudal regression syndrome, including patients with sacral agenesis
and patients with anal atresia or stenosis;
3. Evaluation of suspected defects such as cord tethering, diastematomyelia, hydromyelia,
and syringomyelia;
4. Detection of sequelae of injury, such as:
a.

Hematoma after spinal tap or birth injury;

b. Sequelae of prior instrumentation, infection, or hemorrhage; and

c.

Posttraumatic leakage of cerebrospinal fluid (CSF);

5. Visualization of fluid with characteristics of blood products within the spinal canal in
patients with intracranial hemorrhage;
6. Guidance for lumbar puncture9; and
7. Postoperative assessment for cord retethering.10
Infants with simple, low-lying sacrococcygeal dimples typically have normal spinal contents;
for them, the examination has a low diagnostic yield.3,7 On the other hand, atypical dimples,
such as those larger than 5 mm, located greater than 2.5 cm above the anus, or seen in combination with other lesions, are at higher risk of occult spinal dysraphism.3 A sacral dimple or congenital sinus that is leaking CSF will need further assessment with magnetic resonance imaging, and sonography is therefore not a mandatory first examination in this circumstance.
2

B. Contraindications
1. Preoperative examination in patients with open spinal dysraphism; and
2. Examination of the contents of a closed neural tube defect if the skin overlying the
defect is thin or no longer intact.

IV. Written Request for the Examination

The written or electronic request for an ultrasound examination should provide sufficient
information to allow for the appropriate performance and interpretation of the examination.
The request for the examination must be originated by a physician or other appropriately
licensed health care provider or under the providers direction. The accompanying clinical
information should be provided by a physician or other appropriate health care provider familiar with the patients clinical situation and should be consistent with relevant legal and local
health care facility requirements.

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2011AIUM PRACTICE PARAMETERNeonatal Spine

V. Specifications of the Examination

The examination should be performed with the infant lying in the prone position, although the
study can also be done with the patient lying on his or her side when necessary. A small bolster,
such as a rolled blanket, may be placed under the lower abdomen/pelvis to help position the
patient. The knees may be flexed to the abdomen to allow adequate spacing of the spinous
processes and visualization of the spinal canal contents. An infant who has recently been fed
will generally lie quietly during the examination. If feeding is not possible, a pacifier dipped in
glucose solution will often be helpful in keeping an infant still for an optimal examination. It is
important to note that infants, particularly if not full term, have difficulty maintaining normal
body temperature. Therefore, the examination should be performed in a warm room, and the
coupling agent should be warmed.
The cord should be assessed in the longitudinal and transverse planes, with right and left
labeled on transverse images. The examination may be limited to the lumbosacral region in
specific cases, such as in patients being evaluated for a sacrococcygeal dimple or in those
patients being scanned to look for the presence of hematoma after an unsuccessful or traumatic spinal tap. The entire spinal canal, from the craniocervical junction to the coccyx, may be
included in appropriately selected cases.
The normal cord morphologic characteristics and the level of termination of the conus should
be assessed and documented. To do this, the vertebral body levels need to be accurately identified and numbered. Once the vertebral bodies are clearly numbered, the level of termination
of the conus can be determined. In normal patients, the conus should lie at or above the L2 to
L3 disk space.8,1114 In fetuses and extremely preterm neonates, the normal conus medullaris
may be caudal to the superior endplate of L3.14 In a preterm neonate with a conus that terminates at the L3 midvertebral body, a follow-up sonogram after age correction of 40 weeks
gestation but before age correction of 6 months is warranted.8 The level of termination of the
conus and its configuration should be documented, as well as any deviations from normal.
The vertebral level can be determined in a number of ways.15,16 These include:
1. After assessment of the normal lumbosacral curvature to locate the last lumbar vertebra
or L5, the vertebral level of the conus is determined by counting the cephalad. This
method tends to be more reproducible than the other methods described below, which
rely on counting the number of rib-bearing vertebrae or the number of ossified sacral
and coccygeal segments and can lead to less reliable results.
2. The first coccygeal segment has variable ossification at birth but, if ossified, can be distinguished by its more rounded shape compared with the square or rectangular shape of the
sacral bodies. Counting cephalad from S1 again can help determine the vertebral level of
the conus.

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2011AIUM PRACTICE PARAMETERNeonatal Spine

3. The last rib-bearing vertebra can be presumed to be T12, and the sequential lumbar level
can be thus determined.
4. When the level of the conus cannot be definitively assessed as normal or abnormal, correlation with previous plain radiographs, if available, is helpful. A radiopaque marker can
be placed on the skin at the level of the conus under sonographic guidance, followed by
and correlated with a spine radiograph.
The level of termination of the cord is important in assessment of tethering. The cord position
within the spinal canal and motion of cord and nerve roots are also helpful guidelines in assessment for cord tethering. The normal position of the cord within the spinal canal, and deviation
from normal, such as apposition to the dorsal aspect of the spinal canal as seen in tethering,
should be documented. Cine evaluation can be helpful both in depicting anatomy and in showing movement of the distal cord and nerve roots in conjunction with cardiac-related pulsations
of the spinal CSF. M-mode imaging can also be very helpful in documenting motion of the
cord and nerve roots. The normal nerve roots pulsate freely with cardiac and respiratory
motion, layer dependently with variable patient positioning, and are not adherent to each
other. Cine evaluation can also document changes that occur with head flexion and extension.
A standoff pad or a thick layer of coupling gel may be used, if needed, to follow a tract from the
skin surface.

The integrity of the cord should be documented. Areas of abnormal fluid accumulation, such
as hydromyelia or syringomyelia, anterior, lateral, or posterior meningoceles or pseudomeningoceles, or arachnoid cysts, should be documented and their level identified. Transverse
images are essential to identify and document diastematomyelia, with off-center scanning to
avoid the potential pitfall of a reverberation artifact creating a lateral duplication or ghost
image.17,18
The subarachnoid space should be evaluated for a normal anechoic appearance, interrupted by
normal hyperechoic linear nerve roots and dentate ligaments. The subarachnoid space, dura,
and epidural space should be evaluated, and abnormalities such as hematoma, lipoma, and
other masses should be documented.
In addition to the termination of the conus, the termination of the thecal sac, typically located
at S2, should be documented. The normal filum measures less than 2 mm in thickness. If the
filum is abnormally hyperechoic or appears thickened, it should be measured and documented. The nerve roots of the cauda equina should be delineated within the thecal sac. In cases of
failed lumbar puncture, additional imaging with the child supported in a seated position, bending forward, may be useful to allow gravity to distend the lower thecal sac with CSF.
Upright positioning can be used for image guidance of lumbar puncture or to depict meningoceles or pseudomeningoceles in some patients. Anterior meningoceles or presacral masses
should also be scanned from an anterior position.
The vertebral bodies and posterior elements should be evaluated for deformities. Dysraphic
defects with open posterior elements should be documented on transverse views.

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2011AIUM PRACTICE PARAMETERNeonatal Spine

VI. Documentation
Adequate documentation is essential for high-quality patient care. There should be a permanent record of the ultrasound examination and its interpretation. Images of all appropriate
areas, both normal and abnormal, should be recorded. Variations from normal size should be
accompanied by measurements. Images should be labeled with the patient identification,
facility identification, examination date, and side (right or left) of the anatomic site imaged.
An official interpretation (final report) of the ultrasound findings should be included in the
patients medical record. Retention of the ultrasound examination should be consistent both
with clinical needs and with relevant legal and local health care facility requirements.
Reporting should be in accordance with the AIUM Practice Parameter for Documentation of
an Ultrasound Examination.

VII. Equipment Specifications

Sonography of the infant spine should be performed with real-time scanners using highfrequency linear array transducers, typically 7 to 10 MHz or higher in neonates.19 When possible, panoramic views of the entire spinal canal are very helpful in providing an overview of the
anatomy and termination of the cord and thecal sac. Images of the craniocervical junction may
need to be obtained with a small vector or tightly curved array transducer.
5

VIII. Quality Control and Improvement, Safety, Infection

Control, and Patient Education
Policies and procedures related to quality control, patient education, infection control,
and safety should be developed and implemented in accordance with the AIUM Standards and
Guidelines for the Accreditation of Ultrasound Practices.
Equipment performance monitoring should be in accordance with the AIUM Standards
and Guidelines for the Accreditation of Ultrasound Practices.

IX. ALARA Principle

The potential benefits and risks of each examination should be considered. The ALARA
(as low as reasonably achievable) principle should be observed when adjusting controls that
affect the acoustic output and by considering transducer dwell times. Further details on
ALARA may be found in the AIUM publication Medical Ultrasound Safety, Third Edition.

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Acknowledgments
This parameter was revised by the American Institute of Ultrasound in Medicine (AIUM) in
collaboration with the American College of Radiology (ACR), the Society for Pediatric
Radiology (SPR), and the Society of Radiologists in Ultrasound (SRU) according to the
process described in the AIUM Clinical Standards Committee Manual.

Collaborative Committee
Members represent their societies in the initial draft and final revision of this parameter.

AIUM

AIUM Clinical Standards Committee

Harris L. Cohen, MD
Judy A. Estroff, MD
Charlotte Henningsen, MS, RDMS, RVT

David Paushter, MD, Chair

Leslie Scoutt, MD, Vice Chair
Lisa Allen, BS, RDMS, RDCS, RVT
Mert Bahtiyar, MD
Harris Cohen, MD
Lin Diacon, MD, RDMS, RPVI
Judy Estroff, MD
J. Christian Fox, MD, RDMS
Charlotte Henningsen, MS, RT, RDMS,
RVT
Adam Hiett, MD, RDMS
Lars Jensen, MD
Christopher Moore, MD, RDMS, RDCS
Steven Perlmutter, MD
Olga Rasmussen, RDMS
Carl Reading, MD
Shia Salem, MD
Daniel Skupski, MD
Jay Smith, MD
Lami Yeo, MD

ACR
Marta Hernanz-Schulman, MD, Chair
Lori L. Barr, MD
Leann E. Linam, MD
6

SPR
David A. Bloom, MD
Caroline T. Carrico, MD
Lynn A. Fordham, MD
Martha M. Munden, MD

SRU
Dorothy I. Bulas, MD
Brian D. Coley, MD
Harriet J. Paltiel, MD

Original copyright 2007; Revised 2011

Renamed 2015

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2011AIUM PRACTICE PARAMETERNeonatal Spine

References
1.

Guggisberg D, Hadj-Rabia S, Viney C, et al. Skin markers of occult spinal dysraphism in children:
a review of 54 cases. Arch Dermatol 2004; 140:11091115.

2.

Izci Y, Gonul M, Gonul E. The diagnostic value of skin lesions in split cord malformations. J Clin
Neurosci 2007; 14:860863.

3.

Kriss VM, Desai NS. Occult spinal dysraphism in neonates: assessment of high-risk cutaneous
stigmata on sonography. AJR Am J Roentgenol 1998; 171:16871692.

4.

Ozturk E, Sonmez G, Mutlu H, et al. Split-cord malformation and accompanying anomalies.

J Neuroradiol 2008; 35:150156.

5.

Robinson AJ, Russell S, Rimmer S. The value of ultrasonic examination of the lumbar spine in infants
with specific reference to cutaneous markers of occult spinal dysraphism. Clin Radiol 2005; 60:7277.

6.

Long FR, Hunter JV, Mahboubi S, Kalmus A, Templeton JM Jr. Tethered cord and associated vertebral anomalies in children and infants with imperforate anus: evaluation with MR imaging and plain
radiography. Radiology 1996; 200:377382.

7.

Medina LS, Crone K, Kuntz KM. Newborns with suspected occult spinal dysraphism: a cost-effectiveness analysis of diagnostic strategies. Pediatrics 2001; 108:E101.

8.

Beek FJ, de Vries LS, Gerards LJ, Mali WP. Sonographic determination of the position of the conus
medullaris in premature and term infants. Neuroradiology 1996; 38(suppl 1):S174S177.

9.

Coley BD, Shiels WE II, Hogan MJ. Diagnostic and interventional ultrasonography in neonatal and
infant lumbar puncture. Pediatr Radiol 2001; 31:399402.

10. Gerscovich EO, Maslen L, Cronan MS, et al. Spinal sonography and magnetic resonance imaging
in patients with repaired myelomeningocele: comparison of modalities. J Ultrasound Med 1999;
18:655664.
11. DiPietro MA. The conus medullaris: normal US findings throughout childhood. Radiology 1993;
188:149153.
12. Kesler H, Dias MS, Kalapos P. Termination of the normal conus medullaris in children: a whole-spine
magnetic resonance imaging study. Neurosurg Focus 2007; 23:15.
13. Wilson DA, Prince JR. John Caffey Award: MR imaging determination of the location of the normal
conus medullaris throughout childhood. AJR Am J Roentgenol 1989; 152:10291032.
14. Zalel Y, Lehavi O, Aizenstein O, Achiron R. Development of the fetal spinal cord: time of ascendance
of the normal conus medullaris as detected by sonography. J Ultrasound Med 2006; 25:13971401.
15. Deeg KH, Lode HM, Gassner I. Spinal sonography in newborns and infants, part I: method, normal
anatomy and indications. Ultraschall Med 2007; 28:507517.
16. Lowe LH, Johanek AJ, Moore CW. Sonography of the neonatal spine, part 1: normal anatomy, imaging pitfalls, and variations that may simulate disorders. AJR Am J Roentgenol 2007; 188:733738.
17.

Hedrick WR, Hykes, DL, Starchman DE. Ultrasound Physics and Instrumentation. 4th ed. St Louis,
MO: Elsevier Mosby; 2004.

18. Kremkau FW. Diagnostic Ultrasound: Principles and Instruments. 7th ed. St Louis, MO: Elsevier
Saunders; 2006.
19. Unsinn KM, Geley T, Freund MC, Gassner I. US of the spinal cord in newborns: spectrum of normal
findings, variants, congenital anomalies, and acquired diseases. Radiographics 2000; 20:923938.