Abstract:
Background: Cardiothoracic ratio is a simple and
cheap tool in the estimation of heart size. It is a useful
index of cardiac size evaluation, and a value of 50% is
generally considered to indicate the upper limit of
normal.
Study Objective: This study is to ascertain the normal
mean value in cardiothoracic ratio of Ghanaians using
chest radiography to serve as baseline for screening for
cardiomegaly.
Methodology: Standard postero-anterior radiographs
of the -clients/patients were used in the study. The cardiothoracic
ratio (CTR) was obtained by dividing the
transverse cardiac diameter [sum of the horizontal distances
from the right and left lateral-most margins of
the heart to the midline (spinous processes of the vertebral
bodies)] by the maximum internal thoracic diameter.
Systematic sampling with appropriate inclusion
and exclusion criteria were used to obtain a sample size
of 1989.
Results: The mean transverse cardiac diameter and
cardiothoracic ratio increased with age. The transverse
thoracic diameter increased with age until the sixth
decade when it reduced with age.
The mean CTR increased gradually with age with females
having greater values than males. The mean
CTR of the study population were 0.459, 0.467 and
0.452 for the general population, females and males
respectively.
Conclusion: This study has been able to establish
0.459 as the mean CTR values for Ghanaians. It has
also shown the relationship between age and clients
/patient’s cardiothoracic ratio which compares favourably
with findings of a similar study in Nigeria, a
neighbouring country in the West African sub region
with similar ethnic and social structure.