161.
Bone Growth Plate Imaging: A Morphological and Functional
Magnetic Resonance Study.
Juan Manuel Shiguetomi-Medina, Maja Sofie Kristiansen, Steffen Ringgaard,
Hans Stødkilde-Jørgensen , Ole Rahbek , Bjarne Møller-Madsen
Children's Orthopaedics Department E Aarhus University Hospital NBG; The
MR Research Center, Aarhus University Hospital Skejby; The MR Research
Center, Aarhus University Hospital Skejby; The MR Research Center, Aarhus
University Hospital Skejby; Children´s Orthopaedics Department E, Aarhus
University Hospital NBG; Children´s Orthopaedics Department E, Aarhus
University Hospital NBG
Background:
Magnetic resonance technology allows for morphological and
functional analysis of the bone growth plate which provide information about
early changes caused by disease.
Purpose / Aim of Study:
Proposal and validation of a magnetic- resonance-
based method for studying the bone growth plate including morphological
imaging and water content assessment.
Materials and Methods:
Four tibiae were analyzed ex vivo using a 1.5T MRI
and in vivo tibiae from 8 pigs comparing water-content results to previously
obtained reference parameters from gelatin samples. The method was validated
using dry-freeze technology, and histology samples were correlated to 7T MRI
to validate the morphological imaging.
Findings / Results:
Detailed morphology of the growth plate was observed in
T1 and T2 MRI both ex vivo and in vivo. By in vivo samples imaging higher
signal intensity on the functional sequences, such as water content and
diffusion is obtained - functional magnetic resonance imaging is superior when
done in vivo. We found a direct correlation of the growth plate thickness
obtained by MRI and histology (CV=0.332). It is possible to calculate the
water content from the growth plate using MR T1-mapping. An average
difference of 3.68% (SD=1.2) between dry-freeze and MR values on control
samples, and an average difference of 2.73% (SD=1.3) on cartilage samples
were found.
Conclusions:
Magnetic Resonance imaging provides detailed information
about the morphology of the growth plate. It also provides a functional
overview based on cartilage hydration and can detect early changes caused by
disease. We proved that the linear measurements (thickness, longitude) done
on MR imaging correspond to the structures they resemble, and that we can
rely on T1- map-based water content values as the results correspond to the
water content obtained by dry-freezing.
