Pancreatic MRI for the surveillance of cystic neoplasms: comparison of a short with a comprehensive imaging protocol.

OBJECTIVES

The study aims were to evaluate: (1) whether a short-protocol (SP) MRI for the surveillance of pancreatic cystic neoplasms (PCN) provides equivalent clinical information as a comprehensive-protocol (CP), and (2) the cost reduction from substituting CP with SP for patient surveillance.

METHODS

This retrospective study included 154 consecutive patients (median age: 66, 52 % men) with working-diagnosis of PCN and available contrast-enhanced MRI/MRCP. Three radiologists evaluated independently two imaging sets (SP/CP) per patient. The CP included: T2-weighted (HASTE/MRCP), DWI and T1-weighted (chemical-shift/pre-/post-contrast) images [acquisition time (AT) ≈ 35 min], whereas the SP included: T2-weighted HASTE and T1-weighted pre-contrast images (AT ≈ 8 min). Mean values of largest cyst/main pancreatic duct diameter (D/D) were compared. Agreement regarding presence/absence of cystic/MPD mural nodules (MN/MN), inter-observer agreement and cost differences between SP/CP were calculated.

RESULTS

For D and D, mean values with SP/CP were 21.4/21.7 mm and 3.52/3.58 mm, while mean differences SP-CP were 0.3 mm (p = 0.02) and 0.06 mm (p = 0.12), respectively. For presence/absence of MN and MN, SP/CP coincided in 93 % and 98 % of cases, respectively. Inter-observer agreement was strong for SP/CP. SP-cost was 25 % of CP-cost.

CONCLUSIONS

For the surveillance of PCN, short-protocol MRI provides information equivalent to the more time-consuming and costly comprehensive-protocol.

KEY POINTS

• Pancreatic cystic neoplasms (PCN) are increasingly diagnosed in the general population. • Multiple imaging controls are recommended for the surveillance of patients with PCN. • Short and comprehensive MRI-protocols are equivalent for decision-making in PCN under surveillance. • Evaluation of imaging risk factors in PCNs is comparable with both MRI-protocols. • Use of the short MRI-protocol may rationalise healthcare resources.