BSGAR 2019 Interesting Cases Dr J Mac Pherson

BSGAR 2019 Interesting Cases Dr J Mac. Pherson, Consultant GI Radiologist Dr S Unwin-Golding, Radiology Sp. R North Devon District General Hospital

Background 47 year old male Known polycystic liver and kidney disease. Epigastric pain. Temperature 40. ? intra-abdominal sepsis. Raised ALT/ALP.

Imaging CT abdo/pelvis PV phase : Multiple kidney and liver cysts Gallbladder appeared thinwalled but CBD prominent Suggested ultrasound to help exclude biliary sepsis.

CT cont’d.

CT cont’d.

Ultrasound Gallbladder thin-walled, no surrounding fluid. No gallstones. CBD 9. 5 cm at the porta Difficult to assess intrahepatic ducts due to multiple liver cysts.

Current clinical dilemma Difficult to rule out biliary duct dilatation on background of multiple hepatic cysts Difficulty finding a potentially infected cyst among multiple cysts Most likely diagnoses: biliary sepsis or infected hepatic cyst ? how to differentiate

MRI Multiple cysts in the liver and both kidneys T 1 & T 2 imaging is useful when ageing bleeds into cysts Remains difficult to find an infected cyst among multiple cysts

On diffusion weighted imaging: Area of high signal on the b=800, increase signal with increasing B value. Corresponding low signal on ADC map. DWI

DWI cont’d. 2 - 4 smaller areas of similar signal Largest 2 measuring 14 x 11 mm and 7 x 4 mm These may also represent very small abscesses.

Post-contrast T 1 Largest lesion shows peripheral enhancement post-contrast Consistent with an abscess containing pus

Also of note on MRI (T 2) The CBD appears a little dilated in the pancreas measuring 11 mm. No definite intra- hepatic duct dilatation.

Diagnosis Infected hepatic cyst / abscess. Guided patient’s treatment as source of sepsis Aspiration discussed but deemed too difficult (small cyst, deep within the liver) Patient treated with antibiotics and improved

Key learning points Cyst aspiration is gold standard for diagnosis of infection, but this is not always clinically feasible. Most literature /evidence is about renal cysts, rather than hepatic. 18 F-FDG PET/CT has been used, with good predictive values Lack of literature re: MRI/DWI, but this case shows it can be useful

References / Questions please Yamada I, Aung W, Himeno Y et al. Diffusion coefficients in abdominal organs and hepatic lesions: evaluation with intravoxel incoherent motion echoplanar MR imaging. Radiology 1999; 210: 617– 623 Marten A. Lantinga, Joost P. H. Drenth and Tom J. G. Gevers. Diagnostic criteria in renal and hepatic cyst infection. Nephrol Dial Transplant (2015) 30: 744– 751 doi: 10. 1093/ndt/gfu 227