programma & abstracts - Nederlandse Vereniging voor Radiologie

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programma abstracts & abstracts
were found regarding BME (0.87, 0.88), cartilage lesion
(1.00, 0.97) and bone erosion scores (0.90, 0.93). Regarding
synovial hypertrophy scores, the specificity of -Gd MRI was
98%, though the sensitivity was 60%. ICC for +Gd MRI was
0.88, however omitting post-Gd acquisitions increased interreader
variation (ICC=0.76).
Conclusion: Omitting intravenous contrast is unimportant
in the assessment of bone marrow edema, cartilage lesion
and bone erosion scores in knees of JIA patients, but decreases
the reliability of synovial hypertrophy scores.
O7.3
ULTRASOUND TO PREDICT SIGNIFICANT
HEPATIC STEATOSIS IN OBESE
ADOLESCENTS: POOR POST-TEST
PROBABILITY DESPITE ACCEPTABLE
SENSITIVITY AND SPECIFICITY
A.E. Bohté 1 , B.G. Koot 1 , A.J. Nederveen 1 ,
O.H. van der Baan-Slootweg 2 , S. Bipat 1 , T.H. Pels Rijcken 3 ,
P.L.M. Jansen 1 , M.A. Benninga 1 , J. Stoker 1
1
Academisch Medisch Centrum, Amsterdam
2
Heideheuvel Kliniek, Hilversum
3
Tergooiziekenhuizen, Hilversum
Purpose: to evaluate the post-test probability of ultrasound
(US) for the prediction of hepatic steatosis (HS) in a severely
obese adolescent population with 1 H-MRS as reference
standard.
Methods: HS was prospectively evaluated in 113 obese
adolescents with US and 1 H-MRS. For US, HS was
graded semi-quantitatively as 0:none, 1:mild, 2:moderate,
3:severe). 1 H-MR spectra were acquired with a PRESS
sequence in a voxel of 8cm3 at 3T. The fat fraction (FF) was
calculated as: total fat peak area/reference water peak area.
HS was defined as a FF>1.8% and US score ≥1. Moderate/
severe HS as a FF>7.7% and US score ≥2. Sensitivity and
specificity for both thresholds were calculated. Based on
these values the negative and positive post-test probabilities
were determined and plotted against the prevalence of HS.
Results: Mean age was 14.1y; mean BMI was 38.3 kg/m2.
The overall prevalence of HS was 0.45 (95%CI:0.36-0.54)
with a sensitivity of 0.84 (0.78-0.91) and a specificity of 0.55
(0.46-0.64) for US grade ≥1. The prevalence of moderate/
severe HS was 0.14 (0.08-0.21) with a sensitivity of 0.75
(0.67-0.83) and a specificity of 0.87(0.80-0.93) for US grade
≥2. The positive and negative post-test probabilities are
plotted in fig.1 for both threshold values. The positive posttest
probabilities were low: 0.61 for US grade ≥1 and 0.48
for grade ≥2. Negative post-test probabilities (1-NPV) were
adequate: 0.19 and 0.05 respectively.
Discussion: The positive post-test probability of US for HS
was poor. This implies that the applicability of US to predict
HS in the individual obese adolescent is limited.
Figure 1
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