Prevalence of incidental pancreatic cysts on 3 tesla magnetic resonance

Abstract

Objectives: To ascertain the prevalence of pancreatic cysts detected incidentally on 3-Tesla magnetic resonance imaging (MRI) of the abdomen and correlate this prevalence with patient age and gender; assess the number, location, and size of these lesions, as well as features suspicious for malignancy; and determine the prevalence of incidentally detected dilatation of the main pancreatic duct (MPD).

Methods: Retrospective analysis of 2,678 reports of patients who underwent abdominal MRI between January 2012 and June 2013. Patients with a known history of pancreatic conditions or surgery were excluded, and the remaining 2,583 reports were examined for the presence of pancreatic cysts, which was then correlated with patient age and gender. We also assessed whether cysts were solitary or multiple, as well as their location within the pancreatic parenchyma, size, and features suspicious for malignancy. Finally, we calculated the prevalence of incidental MPD dilatation, defined as MPD diameter ≥ 2.5 mm.

Results: Pancreatic cysts were detected incidentally in 9.3% of patients (239/2,583). The prevalence of pancreatic cysts increased significantly with age (p<0.0001). There were no significant differences in prevalence between men and women (p=0.588). Most cysts were multiple (57.3%), distributed diffusely throughout the pancreas (41.8%), and 5 mm or larger (81.6%). In 12.1% of cases, cysts exhibited features suspicious for malignancy. Overall, 2.7% of subjects exhibited incidental MPD dilatation.

Conclusions: In this sample, the prevalence of pancreatic cysts detected incidentally on 3T MRI of the abdomen was 9.3%. Prevalence increased with age and was not associated with gender. The majority of cysts were multiple, diffusely distributed through the pancreatic parenchyma, and ≥ 5 mm in size; 12.1% were suspicious for malignancy. An estimated 2.7% of subjects had a dilated MPD.

Fig 1. Abdominal MRI (T2-weighted sequence, axial slice), showing a small cyst with thin septum located in the uncinate process of the pancreas.

Fig 2. Abdominal MRI (T2-weighted sequence, axial slice), showing a lobulated cyst located in the body of the pancreas.

Fig 3. Abdominal MRI (T2-weighted sequence, axial slice), showing an additional small cyst located at the transition between body and tail of pancreas.

Same patient as Fig. 2.

Fig 4. Abdominal MRI (T2-weighted sequence with fat saturation, axial slice), showing a lobulated cyst located in the uncinate process of the pancreas.

Fig 5. Abdominal MRI (T2-weighted sequence, coronal slice), showing a lobulated cyst within the uncinate process of the pancreas, with slight parietal thickening.

Same patient as Fig. 4.

Fig 6. Abdominal MRI (T2-weighted sequence with fat saturation, axial slice), showing two small cysts, one in the tail and one in the transition between body and tail of pancreas.

Fig 7. Prevalence of incidental pancreatic cysts according to age.

Fig 8. Prevalence of incidental pancreatic cysts according to gender.