Evolution of the infant spinal column: evaluation with MR imaging

Area of Science:

• Pediatric Radiology
• Spinal Imaging
• Developmental Anatomy

Background:

• The normal appearance of the pediatric lumbar spine on MRI is complex and changes dynamically with growth.
• Variations in signal intensity and morphology can lead to diagnostic confusion in infants.

Purpose of the Study:

• To characterize the sequential changes in the normal pediatric lumbar spine's appearance on MRI.
• To establish distinct developmental stages for the pediatric lumbar spine based on imaging findings.

Main Methods:

• Spinal magnetic resonance imaging (MRI) was performed on 50 pediatric patients aged 2 years or less.
• Both short- and long-repetition-time spin-echo sequences were utilized on a 1.5-T imager.
• Ossification centers, cartilage, and disks of the developing vertebral bodies were analyzed.

Main Results:

• Three characteristic evolutionary stages of the lumbar spine were identified in infants.
• Stage I (0-1 month): hypointense ossification centers, prominent hyperintense cartilage.
• Stage II (1-6 months): increasing ossification center signal, decreasing cartilage.
• Stage III (7+ months): rectangular vertebral bodies, central intensity, diminishing cartilage.

Conclusions:

• The pediatric lumbar spine undergoes significant dynamic changes in signal intensity and morphology during the first two years of life.
• Recognizing these three developmental stages aids in accurate interpretation and dating of pediatric lumbar spine MRIs.
• Careful analysis of these evolutionary changes is essential to avoid misinterpretation of normal developmental findings.