Added value of diffusion-weighted magnetic resonance imaging for the detection of pancreatic fluid collection infection.
OBJECTIVE
To investigate the added value of diffusion-weighted (DW) magnetic resonance (MR) imaging in the detection of infection in pancreatic fluid collections (PFC).


METHODS
Forty-patients with PFC requiring endoscopic-transmural drainage underwent conventional-MR and DW-MR imaging (b = 1000 s/mm2) before endoscopy. MR images were divided into two sets (set1, conventional-MR; set2, conventional-MR, DW-MR and ADC maps) and randomized. Two independent readers performed qualitative and quantitative (apparent diffusion coefficient, ADC) image analysis. Bacteriological analysis of PFC content was the gold standard. Non-parametric tests were used for comparisons. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were calculated for the two sets for both readers. Receiver operating characteristic curves (ROC) were drawn to assess quantitative DW-MR imaging diagnostic performance.


RESULTS
For both readers, sensitivity, specificity, NPV, PPV and accuracy for infected PFCs were higher for set2 (P > .05). ADC were lower in infected versus non-infected PFCs (P ≤ .031). Minimum ADC cut-off: 1,090×10-3mm2/s for reader 1 and 1,012×10-3mm2/s for reader 2 (sensitivity and specificity 67 % and 96 % for both readers).


CONCLUSIONS
Qualitative information provided by DW-MR may help to assess PFCs infection. Infected PFCs show significantly lower ADCs compared to non-infected ones.


CONCLUSIONS
• DW improves MR diagnostic accuracy to detect infection of PFC • Infected PFCs show lower ADC compared to non-infected ones (P < .031) • DW-MR images are easy to interpret especially for non-experienced radiologist.
Polyclinique Santa Maria, 57, Avenue de la Californie, 06200, Nice, France. bb@docteur-borens.com.
Bruno
B
Borens
Department of Gastroenterology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Marianna
M
Arvanitakis
Department of Radiology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Julie
J
Absil
Epicura, 1 Rue Maria Thomée, 7800, Ath, Belgium.
Saïd
S
El Bouchaibi
Department of Radiology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Celso
C
Matos
Department of Gastroenterology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Pierre
P
Eisendrath
Department of Gastroenterology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Emmanuel
E
Toussaint
Department of Gastroenterology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Jacques
J
Deviere
Department of Radiology, Erasme Hospital, 808 Route de Lennik, 1070, Brussels, Belgium.
Maria Antonietta
MA
Bali
D001424:Bacterial Infections / Q000000981:diagnostic imaging* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D010189:Pancreatic Juice / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
Diffusion Magnetic Resonance Imaging; Infection; Magnetic Resonance Imaging; Pancreatic Fluid Collection; Pancreatitis