Contrast-enhanced ultrasound is effective for characterizing renal lesions presenting with equivocal enhancement at CT.

The combination of nodule appearance on T2-weighted MRI and nodule enhancement after gadobenate dimeglumine injection may predict dysplastic nodule diagnosis in patients with liver cirrhosis.

Electrolyte alterations and extra-renal disorders are quite frequent in patients undergoing haemodialysis or peritoneal dialysis. The native kidneys may be the site of important pathologies in patients undergoing dialysis, especially in the form of acquired renal cystic disease with frequent malignant transformation. Renal neoplasms represents an important complication of haemodialysis-associated acquired cystic kidney disease and imaging surveillance is suggested. Extra-renal complications include renal osteodistrophy, brown tumours, and thoracic and cardiovascular complications. Other important fields in which imaging techniques may provide important informations are arteriovenous fistula and graft complications.Teaching points• Renal neoplasms represent a dreaded complication of haemodialysis.• In renal osteodystrophy bone resorption typically manifests along the middle phalanges.• Brown tumours are well-defined lytic lesions radiographically, possibly causing bone expansion.• Vascular calcifications are very common in patients undergoing haemodialysis.• Principal complications of the AV fistula consist of thrombosis, aneurysms and pseudoaneurysms.

We demonstrated how pCT provides good diagnostic accuracy in the identification of acute ischaemic lesions. The limits of identification of the lesions mainly lie at the pons level and in the basal ganglia area. Qualitative analysis has proven to be more efficient in identification of perfusion lesions in comparison with software-generated maps. However, software-generated maps have proven to be very useful in the emergency setting. Advances in knowledge: The use of CT perfusion is requested in increasingly more patients in order to optimize the treatment, thanks also to the technological evolution of CT, which now allows a whole-brain study. The need for performing CT perfusion study also in the emergency setting could represent a problem for physicians who are not used to interpreting the parametric maps (CBV, MTT etc.). The software-generated maps could be of value in these settings, helping the less expert physician in the differentiation between different areas.