HTLV-I-associated myelopathy/tropical spastic paraparesis: semiautomatic quantification of spinal cord atrophy from 3-dimensional MR images.
BACKGROUND
Human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a disabling neurological disorder characterized by inflammatory changes in the spinal cord. We used a semiautomatic technique to quantify spinal cord volume from 3-dimensional MR images of patients with HAM/TSP.


METHODS
Five patients and 5 matched healthy volunteers (HVs) underwent MRI of the cervical and thoracic spinal cord at 1.5 T. Quantification of the spinal cord volume was obtained from 3-dimensional MR images using a semiautomatic technique based on level sets. An unpaired t-test was used to assess statistical significance.


RESULTS
Significant differences were found between mean spinal cord volume of HVs and HAM/TSP patients. The thoracic spinal cord volume was 14,050 ± 981 mm(3) for HVs and 8,774 ± 2,218 mm(3) for HAM/TSP patients (P = .0079), a reduction of 38%. The cervical spinal cord volume was 9,721 ± 797 mm(3) for HVs and 6,589 ± 897 mm(3) for HAM/TSP patients (P = .0079), a reduction of 32%. These results suggest that atrophy is evident throughout the spinal cord not routinely quantified.


CONCLUSIONS
Semiautomatic spinal cord volume quantification is a sensitive technique for quantifying the extent of spinal cord involvement in HAM/TSP.
Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.
Iordanis E
IE
Evangelou
Raya
R
Massoud
Steven
S
Jacobson
D000328:Adult; D000465:Algorithms; D001284:Atrophy; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009187:Myelitis / Q000209:etiology / Q000473:pathology*; D015493:Paraparesis, Tropical Spastic / Q000473:pathology*; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000473:pathology*