Developing epiphysis: MR imaging characteristics and histologic correlation in the newborn lamb

Area of Science:

• Pediatric Radiology
• Skeletal Development
• Histopathology

Background:

• Accurate assessment of bone development in newborns is crucial for identifying growth abnormalities.
• Magnetic resonance (MR) imaging offers non-invasive visualization of skeletal structures.
• Correlation between MR signal characteristics and histologic findings can enhance diagnostic precision.

Purpose of the Study:

• To correlate magnetic resonance (MR) signal characteristics of developing bone regions with their corresponding histologic features.
• To evaluate the utility of MR imaging in differentiating epiphyseal and physeal regions.

Main Methods:

• MR imaging was performed on 36 newborn lamb epiphyses.
• Signal intensity and thickness of cartilaginous regions were analyzed and correlated with histologic sections.
• The influence of T2, magnetization transfer, fat/water content, chemical shift, and anisotropy on signal intensity was assessed.

Main Results:

• MR imaging identified five distinct regions between the secondary ossification center and metaphysis, corresponding to specific histologic zones.
• The thickness of these regions on T1- and T2-weighted images showed a strong correlation with histologic measurements (r = .9).
• Physeal cartilage exhibited greater T2 signal intensity and relaxation time than epiphyseal cartilage (P < .01).

Conclusions:

• MR imaging findings successfully differentiate epiphyseal and physeal regions, aligning with histologic data.
• The observed differences in T2 relaxation times between physeal and epiphyseal cartilage likely indicate variations in water binding.
• MR imaging serves as a valuable tool for evaluating skeletal development in pediatric populations.