Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation(OLT)represents a major treatment for end-stage chronic liver disease,as well as selected cases of hepatocellular carcinoma and acute liver failure.The ever-increasing development of imaging modalities significantly contributed,over the last decades,to the management of recipients both in the pre-operative and post-operative period,thus impacting on graft and patients survival.When properly used,imaging modalities such as ultrasound,multidetector computed tomography,magnetic resonance imaging(MRI)and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT.Less defined is the role for imaging in assessing primary graft dysfunction(including rejection)or chronic allograft disease after OLT,e.g.,hepatitis C virus(HCV)recurrence.This paper:(1)describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice;(2)illustrates main imaging findings related to post-OLTcomplications in adult patients;and(3)reviews future perspectives emerging in the surveillance of recipients with HCV recurrence,with special emphasis on MRI.

Role for contrast-enhanced ultrasound in assessing complications after kidney transplant

Kidney transplantation(KT)is an effective treatment for end-stage renal disease.Despite their rate has reduced over time,post-transplant complications still represent a major clinical problem because of the associated risk of graft failure and loss.Thus,post-KT complications should be diagnosed and treated promptly.Imaging plays a pivotal role in this setting.Grayscale ultrasound(US)with color Doppler analysis is the first-line imaging modality for assessing complications,although many findings lack specificity.When performed by experienced operators,contrast-enhanced US(CEUS)has been advocated as a safe and fast tool to improve the accuracy of US.Also,when performing CEUS there is potentially no need for further imaging,such as contrast-enhanced computed tomography or magnetic resonance imaging,which are often contraindicated in recipients with impaired renal function.This technique is also portable to patients’bedside,thus having the potential of maximizing the cost-effectiveness of the whole diagnostic process.Finally,the use of blood-pool contrast agents allows translating information on graft microvasculature into time-intensity curves,and in turn quantitative perfusion indexes.Quantitative analysis is under evaluation as a tool to diagnose rejection or other causes of graft dysfunction.In this paper,we review and illustrate the indications to CEUS in the post-KT setting,as well as the main CEUS findings that can help establishing the diagnosis and planning the most adequate treatment.