First results of a pilot study to generate normal reference values for shearwave elastography of the pancreas using Acoustic Radiation Force Impulse Virtual Touch Tissue Quantification in healthy subjects

Purpose: The early recognition of changes in the pancreatic parenchyma plays an important role in the diagnosis of pancreatic disorders. The newly developed ultrasound technique of shearwave elastography or Acoustic Radiation Force Impulse Virtual Touch Tissue Quantification (ARFI-VTTQ) visualizes and quantifies tissue elasticity and superimposes findings on conventional B-scan images. Objective of the present study was to establish normal values for the ARFI-VTTQ method in healthy subjects. Material and methods: ARFI-VTTQ was used in a pilot study of 90 healthy volunteers (63.3% females; 36.7% males; mean age 30.2 ± 10.7 years). The size of the head, body and tail of the pancreas was established on B-scan imaging. Thereafter, ARFI-VTTQ was determined at four sites each in the head, body and tail of the pancreas. Measurements were made in m/s. Results: ARFI-VTTQ showed a mean value of 1.3 m/s (SD = 0.3; min = 0.8; max = 2.1). Mean values in the head of the pancreas was 1.3 m/s (SD = 0.4; min = 0.6; max = 2.4), in the body, 1.4 m/s (SD = 0.4; min = 0.8; max = 2.8) and, in the tail, 1.1 m/s (SD = 0.3; min = 0.6; max = 1.8). There was a statistically significant difference of ARFI-VTTQ between men and women ( p = 0.0006). ARFI-VTTQ values increased with age ( p = 0.0001). Conclusion: A broader-based study with a larger collective will be conducted to establish a normal reference range for ARFI-VTTQ of the pancreas. The normal reference range should serve as a basis for delineating pathological ARFI-VTTQ values for different pancreatic pathologies such as chronic pancreatitis, cystic fibrosis and autoimmune pancreatitis.