Longitudinal measurements of MRI-T2 in boys with Duchenne muscular dystrophy: effects of age and disease progression.
Duchenne muscular dystrophy (DMD) is characterized by an increased muscle damage and progressive replacement of muscle by noncontractile tissue. Both of these pathological changes can lengthen the MRI transverse proton relaxation time (T2). The current study measured longitudinal changes in T2 and its distribution in the lower leg of 16 boys with DMD (5-13years, 15 ambulatory) and 15 healthy controls (5-13years). These muscles were chosen to allow extended longitudinal monitoring, due to their slow progression compared with proximal muscles in DMD. In the soleus muscle of boys with DMD, T2 and the percentage of pixels with an elevated T2 (⩾2SD above control mean T2) increased significantly over 1year and 2years, while the width of the T2 histogram increased over 2years. Changes in soleus T2 variables were significantly greater in 9-13years old compared with 5-8years old boys with DMD. Significant correlations between the change in all soleus T2 variables over 2years and the change in functional measures over 2years were found. MRI measurement of muscle T2 in boys with DMD is sensitive to disease progression and shows promise as a clinical outcome measure.
Department of Physical Therapy, University of Florida, USA. Electronic address: rw254@phhp.ufl.edu.
R J
RJ
Willcocks
Department of Physical Therapy, University of Florida, USA.
I A
IA
Arpan
Department of Physical Therapy, University of Florida, USA.
S C
SC
Forbes
Department of Physical Therapy, University of Florida, USA.
D J
DJ
Lott
Department of Physical Therapy, University of Florida, USA.
C R
CR
Senesac
Department of Physical Therapy, University of Florida, USA.
E
E
Senesac
Department of Physical Therapy, University of Florida, USA.
J
J
Deol
Department of Physiology and Functional Genomics, University of Florida, USA.
W T
WT
Triplett
Department of Physiology and Functional Genomics, University of Florida, USA.
C
C
Baligand
Division of Statistics & Scientific Computation, University of Texas at Austin, USA.
M J
MJ
Daniels
Department of Physiology, University of Pennsylvania School of Medicine, USA.
H L
HL
Sweeney
Department of Physiology and Functional Genomics, University of Florida, USA.
G A
GA
Walter
Department of Physical Therapy, University of Florida, USA.
K
K
Vandenborne
D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D002648:Child; D018450:Disease Progression; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007866:Leg / Q000254:growth & development; D008124:Locomotion; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index
30 Foot walk; Duchenne muscular dystrophy; Magnetic resonance imaging; Transverse relaxation time