Accurate quantification methods to evaluate cervical cord atrophy in multiple sclerosis patients.
OBJECTIVE
Automatic accurate measurement techniques are needed to increase reproducibility in the quantification of cervical cord area (CCA) with magnetic resonance (MR) imaging in the assessment of central nervous system (CNS) atrophy in multiple sclerosis (MS) patients.


METHODS
Two segmentation methods were implemented: (1) spatial mean brightness level estimation (SMBLE), and (2) partial-volume modeling (PVM). These were evaluated with the inclusion of spinal cord inclination and/or partial-volume-effect corrections. An averaged manually segmented set was considered as reference. Thirty MR studies were used to compare the different methods. A set of 15 MS patients and 15 control subjects within a two-year longitudinal study were used to evaluate cord atrophy with the best method. Statistical evaluation was made by using an intraclass correlation coefficient and Bland-Altman comparisons.


RESULTS
Partial-volume modeling with spinal cord inclination correction and partial-volume spinal-cord contour contribution estimation was the most accurate method. The longitudinal test showed a 4% decrease in CCA in MS patients with no significant reduction in control subjects.


CONCLUSIONS
The automatic PVM cord-segmentation approach, taking into consideration the spinal-cord inclination and partial-volume treatment, provides reproducibility and increased accuracy in the evaluation of cord atrophy, allowing the monitoring of changes in MS patients.
Carbonell-Caballero
J
J
Medical Informatics Area, ITACA-BET, Polytechnic University of Valencia, and Radiology Department, Hospital Quirón, Valencia, Spain. jocarca1@itaca.upv.es
Manjón
J V
JV
Martí-Bonmatí
L
L
Olalla
J R
JR
Casanova
B
B
de la Iglesia-Vayá
M
M
Coret
F
F
Robles
M
M
D000293:Adolescent; D000328:Adult; D001284:Atrophy / Q000175:diagnosis* / Q000473:pathology; D002138:Calibration; D016022:Case-Control Studies; D002490:Central Nervous System / Q000473:pathology; D002555:Cerebrospinal Fluid / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications* / Q000473:pathology*; D015203:Reproducibility of Results; D012984:Software; D013118:Spinal Cord Diseases / Q000175:diagnosis* / Q000473:pathology*