Measurement of the Angle Between the Superior Mesenteric Artery and the Aorta: Correlation with Body Mass Index

Objective: To discover the mean figures of the distance and angle between the superior mesenteric artery (SMA) and the aorta in four standard acknowledged body mass index (BMI) classifications in an ordinary populace and for the two genders, to work with a computed tomography CT based finding of Superior mesenteric artery syndrome (SMAS). Methods: A retrospective cross-sectional study was performed on 338 (157 female, 181 male) patients who were referred for abdominal CT examination. Age, sex, weight and height of all patients were noted, and the BMI was calculated. The distance between the SMA and aorta were measured, as was the angle. Pearson and Spearman correlation coefficients were used to correlate distance and BMI category, angle and BMI category, anteroposterior abdominal distance and SMA angle with aortomesenteric distance. Results: The mean BMI of patients in our study was 27.95 kg/m2 while the mean SMA angle, mean anteroposterior abdominal wall distance and mean aortomesenteric distance was 58.74 degrees, 224.35 cm, and 18.98 cm, respectively. The results showed positive correlation of BMI and anteroposterior abdominal distance with SMA angle and distance. This means if BMI increases, SMA angle and aortomesenteric distance will also increase, and vice versa. This same relationship was also valid for anteroposterior abdominal distance with aortomesenteric angle and distance. Conclusion: Our study helps in stating the values of aortomesenteric distance and angle for different BMI categories that can be used in CT-based diagnosis of SMAS in a South Asian population. The values we found for different BMI categories can be used by radiologists as a reference standard.