Obesity

Dr Henry Knipe et al.

Obesity is defined as a body mass index (BMI) greater than 30. It is described as being a "modern epidemic" due to increased rates of metabolic syndrome and other complications in these patients, along with a high and increasing prevalence. 

Obesity rates vary around the world but over 60% of the American population is classified as overweight, obese or morbidly obese. 

Aetiology
Classification

BMI is the most widespread classification system and is based on a patient's height and weight, but its generality is questionable, and race/ethnicity and gender should be accounted for 6. The World Health Organisation and National Institute of Health propose the following classification 7:

  • overweight: 25-29.9 kg/m2
  • obese: 30-39.9 kg/m2
  • extremely/severely/morbidly obese: ≥40 kg/m2 or ≥35 kg/m2 with comorbidity

However, in radiology patient weight and thoracoabdominal circumference may be more useful to know in terms of being able to scan due to physical restrictions, e.g. table weight limits and bore diameter 3

Complications

Obesity increases the risk of many conditions including being a risk factor for cancer. It has a significant effect on life expectancy 10,11:

There are numerous challenges when imaging morbidly obese patients, from practical considerations such as transportation, weight limits for imaging equipment and technical points of gaining diagnostic imaging studies. Ultrasound is the most affected modality 4

CT

Image quality can be reduced due to beam hardening artefact and limited field of view, but there is the trade-off of increased contrast due to greater intra-abdominal fat 3

A variety of non-surgical treatments has been attempted in these patients with disappointing results. Surgical approaches to treating obesity, collectively known as bariatric procedures, have been far more promising and are now routinely used to treat patients with morbid obesity 1-2.

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Article Information

rID: 32542
Sections: Gamuts, Pathology
Synonyms or Alternate Spellings:
  • Morbid obesity
  • Extreme obesity

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    Case 6: incomplete imaging despite large FOV
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