ABSTRACT
To disscuss the role of cross‐sectional area measurement under high frequency ultrasound in the diagnosis of congenital adrenal hyperplasia ( CA H ) in infants . Methods T he abdominal ultrasound images of 20 infants with CA H w hich were admitted to our hospital and clinical diagnosised from November 2013 to August 2018 were analyzed retrospectively . T he size of adrenal glands were evaluated by measuring the maximum cross‐sectional area .Fifty normal full‐term infants were selected as control group synchronism . T he size of adrenal glands between infants with CA H and normal infants were compared . T he area under the curve ( AUC ) and best cutoff value were obtained by drawing ROC curve .Sensitivity and specificity were also obtained . Results T here was significant difference in maximum cross‐sectional area of adrenal gland between CA H group and control group[ ( 129 .70 ± 37 .34) mm2 vs ( 54 .41 ± 20 .84) mm2 , t ＝10 .004 , P ＝0 .001] . T he AUC of cross‐sectional area measurement was 0 .966 ,and best cutoff value was 87 .5 mm2 . T he sensitivity and specificity were 95 .0% and 92 .5% . Conclusions High‐frequency ultrasound is convenient and accurate in measuring the maximum cross‐sectional area of adrenal gland in infants . Cross‐sectional area measurement has high sensitivity and specificity to the diagnosis of CA H . T he presence of CA H is highly suspected w hen the area of adrenal gland reached 87 .5 mm2 .