Diagnostic efficacy of abdominal US compared to contrast enhanced CT in the evaluation of the left hepatic lobe volume for morbidly obese patients before bariatric surgery

Bariatric surgery has been widely distributed as an effective treatment method for morbid obesity. An increased volume of the left hepatic lobe may affect the ergonomics of bariatric surgery, which could complicate the surgical techniques and require special instruments. CT of the abdomen is considered the gold standard imaging modality in the assessment of the left hepatic lobe volume; nevertheless, it has some drawbacks, such as exposure to ionizing radiation, besides the contrast and gantry limitations. The objective of this study is to investigate the diagnostic accuracy of abdominal US in comparison to CT in measuring the left hepatic lobe volume in morbidly obese patients as part of their preoperative evaluation. Seventy-two morbidly obese patients of different ages (between 22 and 55 years) and genders were included in this study who were scheduled for bariatric surgery.

The intraclass coefficient and Cronbach's alpha reliability coefficient with their 95% CI were used. There was a strong positive correlation between left hepatic lobe volumes as measured by US and CT (r = 0.999, p value < 0.001), indicating a significant linear relationship between them. The mean of the two variables was very close (474.2 ± 164.9 cm³) by US and (475.1 ± 164.5 cm³) by CT.

Abdominal US examination for assessment of the left hepatic lobe volume is considered a valid diagnostic method compared to CT (with a clinically accepted slight difference between values) in preoperative assessment of morbidly obese patients. It provides an accurate, simple, and inexpensive diagnostic tool that avoids the drawbacks of CT.