In vivo glenohumeral analysis using 3D MRI models and a flexible software tool: feasibility and precision.
OBJECTIVE
To implement a PC-based morphometric analysis platform and to evaluate the feasibility and precision of MRI measurements of glenohumeral translation.


METHODS
Using a vertically open 0.5T MRI scanner, the shoulders of 10 healthy subjects were scanned in apprehension (AP) and in neutral position (NP), respectively. Surface models of the humeral head (HH) and the glenoid cavity (GC) were created from segmented MR images by three readers. Glenohumeral translation was determined by the projection point of the manually fitted HH center on the GC plane defined by the two main principal axes of the GC model.


RESULTS
Positional precision, given as mean (extreme value at 95% confidence level), was 0.9 (1.8) mm for the HH center and 0.7 (1.6) mm for the GC centroid; angular GC precision was 1.3 degrees (2.3 degrees ) for the normal and about 4 degrees (7 degrees ) for the anterior and superior coordinate axes. The two-dimensional (2D) precision of the HH projection point was 1.1 (2.2) mm. A significant HH translation between AP and NP was found.


CONCLUSIONS
Despite a limited quality of the underlying model data, our PC-based analysis platform allows a precise morphometric analysis of the glenohumeral joint. The software is easily extendable and may potentially be used for an objective evaluation of therapeutical measures.
Busse
Harald
H
Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany. herald.busse@medizin.uni-leipzig.de
Thomas
Michael
M
Seiwerts
Matthias
M
Moche
Michael
M
Busse
Martin W
MW
von Salis-Soglio
Georg
G
Kahn
Thomas
T
D000328:Adult; D000704:Analysis of Variance; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D015203:Reproducibility of Results; D012785:Shoulder Joint / Q000033:anatomy & histology*; D012984:Software