Fig. 1.

Quantification of sarcopenia on contrast enhanced computed tomography in patients with pancreatic adenocarcinoma being considered for pancreatectomy. Panel A. Normal patient. Computed Tomography Image taken at the level of the third lumbar vertebral body. The Total Psoas Index is as measure of muscle mass that accounts for patient height and is calculated as (right psoas area + left psoas area/height²). The Hounsfield Unit Average Calculation is a measurement of radiation attenuation thus muscle density and fatty infiltration. The combination of the right and left Hounsfield Unit Measurement is utilized for the HUAC. HUAC = (right HUAC + left HUAC)/2. Right HUAC, Right Hounsfield Unit* Right Psoas Area/Total Psoas Area). Left HUAC is calculated in the same fashion using the left third vertebral body. TPA, Total Psoas Area; HUAC, Hounsfield Unit Average Calculation; HU, Hounsfield Units. Panel B. Patient with Sarcopenia—low Total Psoas Area. Computed Tomography Scan taken at the level of the third lumbar vertebral body. The highlighted area clearly shows small psoas muscle area. Note that the TPA does not account for muscle density. This patient's Total Psoas Index was calculated using the patient's height and met the lowest 25th percentile for sarcopenia [21]. Panel C. Patient with Sarcopenia—low Hounsfield Unit Average Calculation. Computed Tomography Scan taken at the level of the third lumbar vertebral body. The highlighted area demonstrates a patient with a normal TPA (good muscle mass), yet with poor muscle quality. This patient is an example of where muscle mass may not be predictive of complications yet the patient does have sarcopenia. HUAC has been shown to be an independent predictor of complications following pancreatectomy for adenocarcinoma [21]. TPA, Total Psoas Area; HUAC, Hounsfield Unit Average Calculation; HU, Hounsfield Units.