The use of computed tomography (CT) scan in body composition assessment

1. The use of computed tomography
(CT) scan in body composition
assessment
Johnson Mwove
Advances in Nutritional Assessment and
Interventions

2. Introduction
• Body composition refers to the amount of fat and
lean tissues in our body; it is a science that looks
beyond a unit of body weight, accounting for the
proportion of different tissues and its relationship
to health.
• The emerging use of imaging techniques in the
clinical setting has highlighted the importance of
body compositions as predictors of morbidity and
mortality.

3. Introduction
• Body composition health is vital in treatment
decisions, prognostic outcomes, and quality of
life in several nonclinical and clinical states (Prado
& Heymsfield, 2014).
• Body composition can be estimated using
different modalities; anthropometry, body
volume/density, total body water or hydrometry,
major body elements, impedance, imaging/x-ray
attenuation such as computerized tomography
(CT), and multi-compartment models.

4. Computed Tomography (CT) Scan
• A CT scan combines a series of X-ray images taken
from different angles and uses a computer
processing to create cross-sectional images, or slices
of the skeletal muscle, bone, visceral organs, brain
tissue and other soft tissues inside the body.
• As the X-rays passes through the different tissues
attenuation (absorption) occurs differently (Prado &
Heymsfield, 2014).

5. Computed Tomography (CT) Scan
• This attenuation through different tissues is
detected and an image is reconstructed (Prado &
Heymsfield, 2014).
• Sometimes a dye called contrast material, put in a
vein (IV) or placed in other parts e.g. a joint, or
taken as a drink depending on the type of scan,
may be used to help better visualize the organs.

6. Computed Tomography (CT) Scan
• CT scan can be used to visualize nearly all
parts of the body with exquisite anatomical
detail in a brief scan time (Ricciardi, 2016) to
diagnose disease or injury as well as to plan
medical, surgical or radiation treatment
(Adkinson et al., 2017).

7. Advantages of Computed Tomography
(CT) Scan
• It is a highly accurate quantitative and
qualitative measure of body composition at
the tissue-organ level, particularly total and
regional adipose tissue and skeletal muscle
tissue.
• Gives a high image resolution.
• It has a consistent image attenuation value
within and between scans.

8. Advantages of Computed Tomography
(CT) Scan
• It is useful in clinical settings where these images
are acquired for medical diagnosis/ follow-up
purposes.
• CT Scan provides more details than plain X-rays.
The use of computed tomography has been
shown to be superior to plain radiography for the
detection of injuries in important body regions
including the spine, thorax, abdomen and pelvis
(Hunt, Smith, & Oliver, 2012).

9. Advantages of Computed Tomography
(CT) Scan
• Ideal for certain complications where other
options are less useful. CT scan can identify the
highest percentage of sarcopenia in cirrhosis and
no other techniques are actually available as a
replacement (Prado & Heymsfield, 2014).
• It is also well established as the first investigation
of choice for significant traumatic brain injury
(Hunt et al., 2012).

10. Advantages of Computed Tomography
(CT) Scan
• It can be used to predict occurrence of certain
complications or diseases e.g. occurrence of
pancreatic anastomotic failure (PAF) after
pancreatoduodenectomy (Kirihara et al., 2013).
• Results in reduced time to diagnosis and
intervention, as well as significant improvements
in clinical outcome and survival (Hunt et al.,
2012).

11. Disadvantages of Computed Tomography
(CT) Scan
• Limited to highly specialized settings, costly,
and requires specialized skills to operate
(Prado & Heymsfield, 2014)
• Risk of developing cancer - Concerns regarding
the large radiation exposure to ionising
radiation dosage that patients are exposed to
(Hunt et al., 2012; Prado & Heymsfield, 2014).

12. Disadvantages of Computed Tomography
(CT) Scan
• Cannot accommodate very large subjects (patients
who cannot fit in the scanner), (Prado & Heymsfield,
2014)
• There is a perceived risks of the secondary transfer and
scanning room environment itself becoming a source
of the radiation (Hunt et al., 2012).
• The dye used may cause allergic reactions to some
people. If diabetic or taking metformin, the dye may
cause problems.

13. Conclusion
• CT Scans are ideal for diagnostic purposes. They have
been hailed as the better option as compared to other
methods of determining body compositions owing to
their ability to provide better quality images and
providing more information in a short scan time.
• Since they involve exposure to ionizing radiation, there
are safety concerns raised as to the effects of these
radiations on patients.
• Nevertheless, their usefulness has been demonstrated
to outweigh the risks.

14. Thanks