This poster is published under an
open license. Please read the
disclaimer for further details.
Keywords:
Musculoskeletal joint, Musculoskeletal soft tissue, Soft tissues / Skin, MR, Ultrasound, Experimental, Screening, Diagnostic procedure, Experimental investigations, Athletic injuries, Economics, Trauma
Authors:
P. S. Mahajan, P. Chandra, V. C. Negi, A. P. Jayaram, S. A. Hussain; Doha/QA
DOI:
10.1594/ecr2015/C-0348
Results
No significant difference was observed amongst the ACL-injured and control groups for age (P=0.890),
height (P=0.768),
weight (P=0.685),
and gender (P=1.00) using an unpaired Student t test and Chi-square tests [ Table 1 ] .
The control group was adequately matched to the injured group.
Contralateral ACL maximum diameter (near tibial insertion site) for ACL-injured subjects was significantly less than that for non-injured matched control subjects (0.62 ± 0.07 vs 0.81 ± 0.06 cm; P<0.0001).
Stepwise regression analysis showed that body weight was a significant predictor (R=0.357; P=0.016),
while height,
age,
and gender were insignificantly associated with ACL diameter. The mean diameter of the contralateral ACL near tibial insertion site for the injured group was 0.19 cm less than that for a control subject having similar weight (P<0.0001).
The 95% confidence interval (CI) of the mean difference was 1.5 to 2.3 [ Table 2 and Fig. 2 ].
The ACL diameter of all 25 subjects in the ACL-injured group was smaller than their matched controls,
and just 6 subjects had lower body weight.
For the mean body weight of 78.5 kg for the studied population the ACL-injured group had a mean contralateral ACL maximum diameter (near tibial insertion site) of 0.62 cm,
while the control group had a mean diameter (maximum) of 0.81 cm.
The consensus amongst the two recurring measures during validation with MRI measurements demonstrated a very strong agreement (intraclass correlation of 0.87; 95% CI: 0.50 to 0.97) [ Fig. 3 ].
The regression analysis amongst the MRI-measured diameter and the ultrasound-measured diameter revealed a correlation of 0.070,
a slope of 0.052,
and a constant offset of 0.041 cm.
The regression line was almost similar to y = x (slope P=0.05; intercept P=0.051).
We also compared the results of measurements by two radiologists (raters) by conducting an inter-rater accuracy test.
The intraclass correlation coefficient for these 2 radiologists was 0.93 (95% CI: 0.88 to 0.96),
indicating a very strong agreement.
The limits of the [ Fig. 2 ] show a comparison of ultrasound ACL diameter measured by radiologist 1 and radiologist 2 [ Fig. 4 ].
Here the mean difference was -0.01 with 95% CI -0.03 to 0.01.
Thus radiologist 1 tends to give a lower reading,
ranging from -0.03 and 0.01.
Despite this,
the limits of disagreement are considerably low (high agreement) and hence both radiologists provide similar values measuring ultrasound ACL diameter.
Similarly strong agreement was observed when analyzed separately for ACL-injured and control group subjects [ Fig. 5 and Fig. 6 ]. Finally,
the investigation of variance showed a mean systematic difference of 0.3 cm between the 2 radiologists.