A retrospective preliminary study of intrapancreatic late enhancement as a noteworthy imaging finding in the early stages of pancreatic adenocarcinoma.

OBJECTIVE: To characterize intrapancreatic late enhancement (ILE) observed in the early stages of pancreatic adenocarcinoma (PAC). METHODS: Among 203 patients pathologically diagnosed with PAC between October 2011 and February 2021, 32 patients with pre-diagnostic abdominal contrast-enhanced CT performed from 6 months to 5 years before the diagnosis were enrolled in this study. Indirect findings (IFs) on pre-diagnostic CT, including ILE, were evaluated and examined for various clinical data and time intervals to diagnosis (TIDs). The detected ILE was quantitatively evaluated, and the effect of ILE awareness on lesion detection by two radiologists and their interobserver agreement were assessed. RESULTS: Among the 32 patients, 23 showed IFs. ILE was observed in 14 patients (63%), with a median TID of 17 months (interquartile ratio [IQR]: 9.3-42.3). ILE alone was observed in eight patients (35%), ILE with focal pancreatic parenchymal atrophy (FPPA) was observed in five patients (22%), and ILE with main pancreatic duct abnormalities (MPDA) was observed in one patient (4%). Pancreatic head lesions were significantly more frequent in patients with ILE alone than in patients with FPPA or MPDA (p = 0.026). The median long-axis diameters of the region with ILE and ILE-to-pancreas contrast were 10 (IQR: 5-11) mm and 24 (IQR: 17-33) HU, respectively. Awareness of ILE led observers to detect two or three more pancreatic head lesions, and interobserver agreement increased from poor agreement (k = 0.17) to moderate agreement (k = 0.55). CONCLUSION: ILE is a significant IF for early PAC detection. KEY POINTS: • Intrapancreatic late enhancement (ILE) is a significant indirect finding in the early detection of pancreatic adenocarcinoma. • ILE without other indirect findings is expected to help detect pancreatic head lesions. • Image evaluation focusing on ILE can increase lesion detection and improve the interobserver agreement.

Association between visualization of the perivascular space and morphological changes in the brain among the community-dwelling elderly.

PURPOSE: We aimed to investigate the association between perivascular space (PVS) visible on MRI and brain atrophy or morphological change using quantitative indexes. METHOD: This population-based cohort study included 216 older participants. The PVS in basal ganglia (BG-PVS) and cerebral white matter (WM-PVS) was evaluated using a four-point visual rating scale. We segmented brain parenchyma and CSF, and calculated the CSF/intracranial volume ratio, which represents atrophic change. WM lesions were classified using the Fazekas scale. We introduced a new category "idiopathic normal pressure hydrocephalus (iNPH)-like conformation", which was based on two quantitative indexes: Evans index and callosal angle. The association between PVS grade and demographic or morphological factors was evaluated. RESULTS: A stepwise increase in the CSF/intracranial volume ratio with BG-PVS grade progression and a stepwise decrease with WM-PVS grade progression were observed. A higher CSF/intracranial volume ratio was significantly related to a higher BG-PVS grade in a univariate analysis, but this significance disappeared in a multivariate analysis. The iNPH-like group was significantly related to a lower WM-PVS grade in a univariate analysis, and this significance remained in a multivariate analysis. CONCLUSIONS: The association between BG-PVS enlargement and atrophic changes was verified. On the contrary, WM-PVS showed a different trend, and a lower WM-PVS grade was associated with an iNPH-like conformation. This result implies that the less-visible WM-PVS on imaging as well as BG-PVS enlargement would reflect abnormal brain change.