Ultrashort-echo time MR imaging of the patella with bicomponent analysis: correlation with histopathologic and polarized light microscopic findings.
OBJECTIVE
To correlate short and long T2* water fractions, derived from ultrashort-echo time (TE) magnetic resonance (MR) imaging, with semiquantitative histopathologic and polarized light microscopic (PLM) assessment of human cadaveric patellae cartilage.


METHODS
Twenty human cadaveric patellae were evaluated by using ultrashort-TE imaging, spin-echo imaging, histopathologic analysis, and PLM, with institutional review board approval. Short and long T2* water components were evaluated for each patella by using bicomponent fitting of ultrashort-TE signal decay. Four to six regions of interest (ROIs) within each patella were chosen for correlation between ultrashort-TE bicomponent analysis, histopathologic grading (Mankin score), and PLM grading (Vaudey score).


RESULTS
Ultrashort-TE imaging with bicomponent analysis showed two distinct water components with a short T2* and a longer T2* in all patellae. ROI analysis showed that the short T2* fraction was correlated significantly with the Mankin (ρ = 0.66, P < .001) and Vaudey (ρ = 0.68, P < .001) scores. The Mankin scores were weakly positively correlated with T2 (ρ = 0.28, P = .13) and short T2* (ρ = 0.24, P = .14) but were negatively correlated with long T2* (ρ = -0.55, P < .01). The Vaudey scores were weakly positively correlated with T2 (ρ = 0.18, P = .16) and short T2* (ρ = 0.22, P = .14) but were negatively correlated with long T2* (ρ = -0.55, P < .01).


CONCLUSIONS
Short T2* water fraction derived from ultrashort-TE imaging with bicomponent analysis correlates significantly with both the Mankin and Vaudey scores and may serve as a biomarker of cartilage degeneration.
Department of Molecular and Experimental Medicine, the Scripps Research Institute, La Jolla, CA, USA.
Chantal
C
Pauli
Won C
WC
Bae
Michael
M
Lee
Martin
M
Lotz
Graeme M
GM
Bydder
Darryl L
DL
D'Lima
Christine B
CB
Chung
Jiang
J
Du
D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D002358:Cartilage, Articular / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008859:Microscopy, Polarization; D008875:Middle Aged; D010329:Patella / Q000473:pathology*; D015203:Reproducibility of Results