Liver lesions: a prevalence study in a healthy population

Background: The widespread use of modern abdominal imaging techniques has led to an increase in incidentally detected hepatic lesions. The aim of this study is to investigate the prevalence of liver lesions and simple cysts in the general population. Methods: Liver lesions and simple cysts were detected by retrospective analysis of MRI reports from all consecutive persons who underwent abdominal MRI at a center of preventive medical care between April 2010 – April 2011. The abdominal MRI is part of a medical screening and self-initiated by the participants, without doctor’s referral. Anamnesis forms were studied for general demographics, medication use, medical history and abdominal complaints. Results: During the study period, 2668 persons (60% male), had abdominal MRI imaging. The mean age of the population was 53.1 ± 11.2 yrs, with a mean BMI of 25.9 ±3.7. Comparison to data of a Dutch survey study (Centraal Bureau voor de Statistiek) revealed that the study population is very similar to the general Dutch population concerning general demographics. Analysis of MRI reports showed that 759 persons (28.4%) had hepatic simple cysts. Most hepatic cysts were small (< 3 cm in 95.3%), multiple (60.9%) and more often located in the right lobe (41.8% versus 30.7% left). The prevalence increased with age. Hepatic cysts correlated with the use of anti-diabetic medication, whereas no correlations were found with BMI or gender. Forty-eight percent of the persons with hepatic cysts also reported cysts in other organs; 40.8% had hepatic and renal cysts, 1.3% hepatic and splenic cysts, and 1.7% hepatic and pancreatic cysts. The prevalence of renal and pancreatic cysts increased with age. Hepatic hemangiomas had a prevalence of 6,4%, which was higher in females (F:M, 1,3:1) and were found significantly more often in the right lobe (72.3% versus 17.6% left). The prevalence of hemangiomas was not age related and correlated with oral contraceptives. Conclusions: This study in a healthy population without major complaints revealed high prevalence’s of hepatic cysts and hemangiomas. In addition, also the prevalence of simple cysts in other organs was found to be high. Analysis indicated that hepatic and pancreatic cysts increased with age, and occurred often with concomitant cysts in other organs. To our knowledge this is the first study to evaluate such prevalence rates in a large, healthy population by MRI imaging. Comparison to data of a Dutch survey study indicated similar demographics which may imply that the prevalence rates are applicable to the general Dutch population.