Reproducibility of dGEMRIC in assessment of hip joint cartilage: a prospective study.
OBJECTIVE
To investigate the reproducibility of dGEMRIC in the assessment of cartilage health of the adult asymptomatic hip joint.


METHODS
Fifteen asymptomatic volunteers (mean age, 26.3 years +/- 3.0) were preliminarily studied. Any volunteer that was incidentally diagnosed with damaged cartilage on MRI (n = 5) was excluded. Ten patients that had no evidence of prior cartilage damage (mean age, 26.2 years +/- 3.4) were evaluated further in this study. The reproducibility of dGEMRIC was assessed with two T1(Gd) exams performed 4 weeks apart in these volunteers. The protocol involved an initial standard MRI to confirm healthy cartilage, which was then followed by dGEMRIC. The second scan included only the repeat dGEMRIC. Region of interest (ROI) analyses for T1(Gd)-measurement was performed in seven radial reformats. Statistical analysis included the student's t-test and intra-class correlation (ICC) measurement to assess reproducibility.


RESULTS
Overall 70 ROIs were studied. Mean cartilage T1(Gd) values at various loci ranged from 560.9 ms to 684.4 ms at the first set of readings and 551.5 ms to 662.2 ms in the second one. The mean difference per region of interest between the two T1(Gd)-measurements ranged from 21.4 ms (3.7%) to 45.0 ms (6.8%), which was not found to be statistically significant (P = 0.153). There was a high reproducibility detected (ICC range, 0.667-0.915). Intra- and Inter-observer analyses proved a high agreement for T1(Gd) assessment (0.973 and 0.932).


CONCLUSIONS
We found dGEMRIC to be a reliable tool in the assessment of cartilage health status in adult hip joints.
Bittersohl
Bernd
B
Department of Orthopedic Surgery, Inselspital, Bern, Switzerland.
Hosalkar
Harish S
HS
Haamberg
Tanja
T
Kim
Young-Jo
YJ
Werlen
Stefan
S
Siebenrock
Klaus A
KA
Mamisch
Tallal C
TC
D000328:Adult; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006621:Hip Joint / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007592:Joint Diseases / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
D003287:Contrast Media; D019786:Gadolinium DTPA