Utility of MRI in detection of PET-CT proven local recurrence of pancreatic adenocarcinoma after surgery.

The aim of this prospective study was to investigate the accuracy and inter-observer reliability of MRI in detection of local recurrence (LR) of pancreatic adenocarcinoma (PAC) after surgery, which was proved by PET-CT and access correlation between functional MRI and PET parameters. Forty-five patients who underwent PET-CT and MRI for follow-up purposes after radical operation of PAC were included. Twenty-three were PET positive (study group) and 22 negative for LR (control group). MR examination was performed within one month after PET-CT and three readers who were blind for PET-CT findings searched LR in T2W, 3D-dynamic post-contrast T1W-FS and DWI sequences, respectively. Sensitivity and specificity were calculated while inter-reader agreement was estimated by Cronbach's Alpha reliability coefficient (CARC). Apparent diffusion coefficient (ADC) of LR was correlated with the size (maximal diameter) and functional PET-CT parameters: mean and maximum standardized uptake values (SUVmean, SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), using Spearman's correlation coefficient (rS). Sensitivity and specificity among three readers in detecting the LR were 70% and 77-84% in T2W (CARC 0.806), 91-100% and 100% in 3D post-contrast T1W-FS (CARC 0.980), and both 100% in DWI sequences (CARC 1.000). Moderate inverse correlation was found between the ADC and SUVmean (rS = - 0.484), MTV (rS = - 0.494), TLG (rS = - 0.519) and lesion size (rS = - 0.567). MRI with DWI shows high diagnostic accuracy in detecting the LR of PAC in comparison to PET-CT as reference standard. ADC significantly inversely correlates with standard and advanced PET parameters and size of LR.

Visualization of the fat planes between the pancreas and the adjacent organs and blood vessels using multi-detector computed tomography.

PURPOSE: To explore individual variations in visibility of the fat planes between the pancreatic parenchyma and adjacent organs and blood vessels using the multi-detector-computed tomography (MDCT). METHODS: Abdominal contrast-enhanced MDCT examinations of 520 consecutive adult individuals were retrospectively analysed by exploring the presence of visible fat planes between the healthy pancreas and the following surrounding structures: stomach, descending duodenum (D2), splenic, portal, superior mesenteric vein (SV, PV, SMV), inferior vena cava (IVC), and coeliac trunk, common hepatic and superior mesenteric artery (CT, HA and SMA). Spearman's rank correlation coefficient (rS) was used to assess the correlation of individual gender, age, body mass and BMI, and visible fat planes towards particular surrounding structures. RESULTS: Fat planes between the pancreatic parenchyma and surrounding structures was visible as follows: stomach in 76%, D2 11.7%, SV 51.5%, PV 0%, SMV 28.8%, IVC 80.8%, CT 99.4%, HA 90.4% and SMA in 100% participants. The presence of visible fat planes significantly correlated (p < 0.001) with body mass for stomach (rS = 0.367), D2 (rS = 0.247), SV (rS = 0.355), SMV (rS = 0.384) and IVC (rS = 0.259); BMI for stomach (rS = 0.292), SV (rS = 0.248), SMV (rS = 0.290) and IVC (rS = 0.216); age for D2 (rS = 0.363), SV (rS = 0.276) and SMV (rS = 0.409); and male gender for stomach (rS = 0.160) and SV (rS = 0.198). CONCLUSION: Fat planes around the pancreatic parenchyma in the MDCT scan was almost always visible towards the adjacent magistral visceral arteries and IVC, always invisible towards the PV, and variably visible towards the SV, SMV, stomach and duodenum depending on the individual body mass, BMI, age and gender.