Comparison of Abdominal Aorta Palpation With Ultrasound Imaging Measurements in Healthy Individuals

Purpose: Palpation is a traditional physical exam tool used to screen for abdominal aorta aneurysm. The purpose of this study was to determine agreement and reliability of abdominal aorta palpation measurements compared to point of care ultrasound (POCUS) measurements by novice physical therapy examiners in healthy individuals. Methods: Fifty healthy subjects over age 18 participated (age 25.2 ± 3.4). Two novice physical therapy examiners, blinded to each other's findings, measured infrarenal abdominal aorta width using a two-finger palpation technique and with POCUS, using a Vscan Air™ handheld ultrasound device, in randomized order. Bland–Altman analysis and paired t-tests compared agreement between palpation and POCUS measurements. Twenty-five participants returned within a month to assess intrarater reliability. Results: POCUS abdominal aorta width measurements averaged 1.54 cm (SD = 0.21), whereas palpation measurements averaged 2.51 cm (SD = 1.07), with a mean difference of 0.97 cm (SD = 1.03; 95% CI [0.67, 1.26]; P < .001). Palpation and POCUS measurements showed a positive correlation of 0.319 (P = .025); however, agreement decreased as aorta size increased. Intrarater reliability for POCUS had an intraclass correlation coefficient (ICC) of 0.58 (95% CI [0.25, 0.79]), and palpation showed intrarater reliability ICC of 0.59 (95% CI [0.25, 0.80]). Conclusions: Palpation overestimates infrarenal abdominal aorta width compared to POCUS in healthy individuals when performed by novice physical therapy examiners. While moderate agreement with POCUS exists, palpation accuracy decreases as aorta size increases, showing more variability. Further validation is needed in physical therapy examiners with more experience and in individuals with abdominal aortic aneurysm.