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I. Imaging of Spine Disorders In Children: Dysraphism and Scoliosis.
II. Authors
L. Santiago Medina, MD, MPH
Diego Jaramillo, MD, MPH
Esperanza Pacheco-Jacome, MD
Martha Ballesteros, MD
Tina Young Poussaint, MD
Brian E. Grottkau MD
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KEY POINTS
ISSUES
A. Spinal Dysraphism:
1. How accurate is imaging in occult spinal dysraphism?
2. Defining risk of occult spinal dysraphism (OSD)
3. What is the natural history and role of surgical intervention in occult spinal dysraphism (OSD)?
4. What is the cost-effectiveness of imaging in occult spinal dysraphism?
B. Scoliosis
1. How should the radiographic evaluation of scoliosis be performed?
2. What radiation-induced complications result from radiographic monitoring of scoliosis?
3. What is the use of MRI for severe idiopathic scoliosis?
4. What is the use of MRI for high-risk subgroups of scoliosis?
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IV Key Points:
Spinal Dyraphism
•The prevalence of OSD ranges from as low as 0.34% in children with intergluteal dimples to as
high as 46% in newborns with cloacal malformation. (Moderate Evidence).
•MRI and ultrasound have better overall diagnostic performances (ie, sensitivity and specificity)
than plain radiographs (Moderate Evidence) in children with suspected occult spinal dysraphism
•Early detection and prompt neurosurgical correction of occult spinal dysraphism may prevent
upper urinary tract deterioration, infection of dorsal dermal sinuses, or permanent neurologic
damage (Moderate and Limited Evidence).
•Cost-effectiveness analysis suggests that, in newborns with suspected OSD, appropriate selection
of patients and diagnostic strategy may increase quality-adjusted life expectancy and decrease cost
of medical workup (Moderate Evidence).
Scoliosis
• Radiographic measurements of scoliosis are reproducible, particularly when the levels of the end
plates measured are kept constant (Moderate Evidence). Unexpected findings on radiographs are
unusual (Limited Evidence).
• Radiographic monitoring of scoliosis results in a clear increase in the radiation-induced cancer
risk, particularly to the breast (Moderate Evidence). It also results in a high dose of radiation to the
ovaries and worsens reproductive outcome in females (Moderate Evidence). Therefore, it is very
important to reduce the radiation exposure. Postero-anterior projection greatly reduces exposure,
and some digital systems also decrease radiation.
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• Minimal tonsillar ectopia (< 5mm) is significantly prevalent in scoliosis and correlates with
abnormalities in somatosensory-evoked potential and with the severity of scoliosis (Moderate
Evidence). Otherwise, a paucity of significant findings on MR images of patients evaluated for
idiopathic scoliosis is noted, even in severe cases.
• Unlike adolescent idiopathic scoliosis, juvenile and infantile idiopathic scoliosis and congenital
scoliosis have a high incidence of neural axis abnormalities (Limited Evidence). Increase incidence
of neural axis abnormalities have also been seen with atypical idiopathic scoliosis and left
(levoconvex) thoracic scoliosis (Limited Evidence).
IX.
Issues in Spinal Dysraphism
Issue 1: How accurate is Imaging?
Summary
Several studies have shown that MRI and ultrasound have better overall diagnostic performances
(ie, sensitivity and specificity) than plain radiographs (Moderate Evidence). The sensitivity of
spinal MRI and ultrasound has been estimated at 95.6% and 86.5%, respectively. The specificity of
spinal MRI and ultrasound has been estimated at 90.9% and 92.9%, respectively. Conversely, the
sensitivity and specificity of plain radiographs have been estimated at 80% and 18%, respectively.
Issue 2: Defining risk of occult spinal dysraphism.
Summary
The prevalence of OSD ranges from as low as 0.34% in children with intergluteal dimples to as
high as 46% in newborns with cloacal malformation. (Moderate Evidence). Table 2 summarizes
the spectrum of occult spinal dysraphism into low, intermediate and high risk groups.
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Issue3 : What is the natural history and role of surgical intervention in occult spinal
dysraphism?
Summary
Early detection and prompt neurosurgical correction of occult spinal dysraphism may prevent
upper urinary tract deterioration, infection of dorsal dermal sinuses, or permanent neurologic
damage (Moderate and Limited Evidence). Several studies have demonstrated that motor function,
urologic symptoms, and urodynamic patterns may be improved, stabilized or prevented by early
surgical intervention in patients with occult spinal dysraphism (Moderate and Limited Evidence).
The surgical outcome may be better if intervention occurs before the age of 3 years (Moderate and
Limited Evidence). Spinal neuroimaging, therefore, has the important role of determining the
presence or absence of an occult spinal dysraphic lesion so that appropriate surgical treatment can
be instituted in a timely manner.
At our institution, occult dysraphic lesions diagnosed in the newborn period are usually operated at
age 2-3 months. Therefore, if ultrasound is indicated, it is performed in the early newborn and
infancy period to avoid a limited sonographic window from posterior element mineralization. If
MRI is required, it is usually performed a few days before surgery.
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Issue 4:What is the cost-effectiveness of imaging in children with occult spinal dysraphism?
Summary
Cost-effectiveness analysis suggests that, in newborns with suspected OSD, appropriate selection
of patients and diagnostic strategy may increase quality-adjusted life expectancy and decrease cost
of medical workup.
Issues in Scoliosis
Issue 1 : How should the radiographic evaluation of scoliosis be performed?
Summary
Radiographic measurements of scoliosis are reproducible, particularly when the levels of the end
plates measured are kept constant (Moderate Evidence). Unexpected findings on radiographs are
unusual (Limited Evidence).
Issue 2: What radiation-induced complications result from radiographic monitoring of
scoliosis?
Summary
Patients with severe scoliosis are monitored with the use of serial radiographs that expose the body
to radiation. Radiographic monitoring of scoliosis results in a clear increase in the radiationinduced cancer risk, particularly to the breast (Moderate Evidence). It also results in a high dose of
radiation to the ovaries and worsens reproductive outcome in females (Moderate Evidence).
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Therefore, it is very important to reduce the radiation exposure. Posteroanterior projection greatly
reduces exposure, and some digital systems also decrease radiation.
Issue 3: What is the use of magnetic resonance imaging for severe idiopathic scoliosis?
Summary
There is increasing concern about the association of idiopathic scoliosis with structural
abnormalities of the neural axis. Minimal tonsillar ectopia (< 5mm) is significantly prevalent in
scoliosis and correlates with abnormalities in somatosensory-evoked potential and with the
severity of scoliosis (Moderate Evidence). Otherwise, a paucity of significant findings on MR
images of patients evaluated for idiopathic scoliosis is noted, even in severe cases.
Issue 4 : What is the use of magnetic resonance imaging for high-risk subgroups of scoliosis?
Summary
Unlike adolescent idiopathic scoliosis, juvenile and infantile idiopathic scoliosis and congenital
scoliosis have a high incidence of neural axis abnormalities (Limited Evidence). Increase incidence
of neural axis abnormalities have been seen with atypical idiopathic scoliosis and left (levoconvex)
thoracic scoliosis (Limited Evidence).
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Table 2.
Risk Groups for Occult Spinal Dysraphism
Variable
Baseline Value
Reference
Low Risk Group
Offsprings of diabetic mothers
Intergluteal dimples
Lumbosacral dimple
0.3%
0.34%
3.8%
63-66
25,63
29
Intermediate Risk Groups
Low anorectal malformation
Intermediate anorectal malformation
Complex skin stigmata a
27%
33%
36%
67
67
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High Risk Group
High anorectal malformation
Cloacal malformation
Cloacal exstrophy
44%
46%
100%
67
21
21
a = hemangiomas, hairy patches, and subcutaneous masses
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