Background & Aims: Emerging minimally invasive treatments for hepatocellular carcinoma (HCC) can significantly improve a patient’s prognosis, but they may alter the imaging features of the treated nodules. This study focuses on a series of patients presenting with a rare pathology, the nodule-in-nodule imaging pattern of HCC, analyzes the imaging features and discusses possible approaches for the diagnosis of tumoral recurrence.Method: Nine patients recruited over two years, having HCC with nodule-in-nodule imaging pattern on diagnosis, and treated by transarterial chemoembolization were monitored by magnetic resonance imaging (MRI). Nodule morphology, dynamic contrast behavior and size progression were followed in this study.Results: All patients showed tumor recurrence. In 7 nodules, a T2 weighted-imaging hyperintense signal of the HCC foci was found, with isointensity of the background nodule. Restricted diffusion within the HCC foci was found in 6 cases but with no statistical significance. Dynamic contrast images evaluation showed a “classical” enhancement pattern in five patients. All nodules had hypointense HCC foci in the hepatobiliary phase. Four patients demonstrated progressive disease according to the mRECIST criteria.Conclusions: Due to the particularly challenging nodule characteristics, the sensitivity in diagnosing HCC foci in these nodules is about 77% when using conventional imaging criteria related to nodule morphology. Contrast media uptake curves may be altered by changes in nodule hemodynamics caused by embolization. The diagnostic rate may be significantly increased by considering the tumoral size increase in follow-up studies and completing the study with a hepatobiliary phase using Acidum Gadoxeticum.Abbreviations. ADC: Apparent diffusion coefficient; CT: Computed tomography; DEB-TACE: drug-eluting beads transarterial chemoembolization; DWI: Diffusion-weighted imaging; Gd-EOB-DTPA: acidum gadoxeticum; HCC: hepatocellular carcinoma; HBV: hepatitis virus B; HCV: hepatitis virus C; HDV: hepatitis virus D; IN-OPP: in-phase and out-of-phase; mRECIST: modified Response Evaluation Criteria in Solid Tumors; MRI: Magnetic resonance imaging; ROI: region of interest; TACE: Transarterial chemoembolization; WI: weighted imaging.

The glutamate-glutamine cycle is essential for sustaining the neuronal secretion of the excitatory neurotransmitter glutamate. Hepatic encephalopathy, even in its most discreet form, minimal hepatic encephalopathy (MHE), interferes with the glutamate and glutamine balance due to the increase in ammonia levels in the central nervous system (CNS), induced by a combination of liver dysfunction, increased blood-brain barrier permeability and many other factors. An experimental study on 21 patients with chronic liver disease and 11 healthy volunteers was performed. Magnetic resonance spectroscopy demonstrated an increase of the glutamate-glutamine complex peak, with high predictive value for MHE, especially when the metabolites are referenced to creatine, a stabile metabolite in the CNS. This paper also explores the pathophysiology of MHE with emphasis on the involvement of the glutamate-glutamine cycle in the development of this complication.

Pancreatic pseudocysts are often complications of acute pancreatitis and chronic pancreatitis, secondary to pancreatic trauma or pancreatic duct obstruction. Computer tomography (CT) is the standard investigation for the diagnosis of pancreatic pseudocysts, but Magnetic Resonance Imaging (MRI) is a better alternative for the detection and characterisation of this pathology. We present a case of a 43 year old male admitted with ascites who was investigated mainly by CT, both pre and post-operative, but also by MRI. The presented case illustrates an arterialized pancreatic pseudocyst, which is a rare complication associated with chronic pancreatitis. This case shows the importance of CT examination in pancreatic cystic lesions with vascular involvement. For unstable patients and modified cystic mass content, CT is the best imaging choice for evaluation and characterization.