Discussion
A large proportion of retained foreign bodies following trauma are
organic foreign bodies [1].
Detection of these organic foreign bodies is particularly important as
it may serve as a
nidus for superimposed infections. [2] If these
foreign bodies are left undetected, they may cause
serious complications like, abscess, fistula and obstructive
bronchiectasis resulting in recurrent
chest infections.[3]
Despite advances in imaging, they remain quite difficult to detect &
diagnose.
Radiographs have been reported to reveal wooden foreign bodies in about
only 15% of the
cases.[1] CT scans are helpful in evaluation &
detection of wooden & bamboo foreign
bodies.[4,5] However, the attenuation largely
depends on its porosity, water & air content. Bodne
et al. [6] cited cases of wooden foreign bodies
exhibiting different attenuation values ranging from
very low (close to air) in acute to high (close to calcium) in chronic
cases. Another study has also
concluded that all dry and wet wooden & bamboo foreign bodies mimicked
air in linear shape
which may cause difficulty in detected within air filled spaces, such as
nasal cavity, sinuses &
tracheobronchial tree.[7]
In our case attenuation value measured within the foreign body & walls
were 11 HU & 545 HU
respectively indicating fluid filled lumen & calcified walls. Since the
patient didn’t survive till
the surgical extraction, the exact nature of the foreign body was not
found. However, coupled
with the patient’s past history of trauma & the appearance of foreign
body which was cylindrical,
fluid filled structure with dense walls it was assumed to be bamboo.
According to Nakata et
el. [8] bamboo often presented as cylindrical
structures with high density and unlike many
wooden foreign bodies, bamboo appears to maintain its cylindrical
structure for many years.