A hypoechoic area within the head of the pancreas--a normal variant

Using conventional pancreatic ultrasonography 32 healthy volunteers were studied to assess the prevalence of a previously undescribed well demarcated hypoechoic area within the head of the pancreas. There was definite evidence of a hypoechoic region in nine subjects (28.1%), possible evidence in five (15.6%) and no evidence in 18 (56.3%). In accordance with the structural differences that have been described between the embryologically derived ventral and dorsal pancreatic segments it is proposed that this area of hypoechogenicity is the ventral portion of the pancreas. To date any focal hypoechogenicity within the head of the pancreas has been considered abnormal, but in view of these findings we feel it is important to recognise that a well demarcated hypoechoic region within the head of the pancreas can be a normal variant.