Sonographic measurement of thymic size in preterm infants: prediction model for thymic size in the Indian subcontinent.
OBJECTIVE
To study the relationship of thymic size in vivo in preterm infants with gestational age (GA), birth-weight (BW) and length of the baby.


METHODS
Two hundred consecutive preterm, appropriate for GA, asymptomatic neonates with GA between 26 and 36 wk and BW between 1000 and 2700 g were examined during the first week following delivery. Neonates of mothers with medical complications were excluded from the study. Thymic size was assessed sonographically and thymic index (Ti) was calculated.


RESULTS
The mean gestational age was 32.62 ± 2.32 wk, the mean birth weight was 1850 ± 41 g and the mean length was 42.93 ± 3.09 cm. The number of boys were 109 (54.5%) and the number of girls were 91 (45.5%). The mean Ti in boys (4.11 ± 2.10) was similar to that in girls (4.36 ± 2.05). Thymic index was positively correlated with GA and length and the correlation was not significant with BW and sex of the infant.


CONCLUSIONS
The sonographic method is a safe and effective technique for measuring the size of the thymus in preterm infants. A normal range of Ti has been established and correlates positively with GA and length and negatively with BW and sex of the preterm infants of the Indian subcontinent.
Department of Radiodiagnosis, Pandit Bhagwat Dayal Sharma, Post Graduate Institute of Medical Sciences, Rohtak, 124001, Haryana, India. snkmagu@gmail.com
Sarita
S
Magu
Geeta
G
Gathwala
Shalini
S
Agarwal
Anit
A
Parihar
D017677:Age Distribution; D001724:Birth Weight; D001827:Body Height; D005260:Female; D005865:Gestational Age; D006801:Humans; D007194:India; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008954:Models, Biological; D012016:Reference Values; D017678:Sex Distribution; D013950:Thymus Gland / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014463:Ultrasonography