Non-Invasive Diagnosis of Acute Renal Allograft Rejection − Special Focus on Gamma Scintigraphy and Positron Emission Tomography

Abstract

The number of patients treated for end-stage renal failure continuously increases. "ecause treatment alternatives are limited and transplants are often the first therapeutic choice, the numbers of patients joining the waiting lists in countries world-wide rises. "t present transplantation medicine is one of the most progressive fields of medicine. Gradually the half-life of renal transplants improved and the five years survival rate ranges now above % [ ]. Despite of the advances made within the last decades, acute rejection "R is still a risk for graft survival. The incidence of rejection episodes depends on several factors, e.g., the organ status , co-morbidities, medication and compliance. Thus, in different situations the incidence of "R varies between -% in the first year after transplantation [ ], and, in most cases, cellular and humoral immunity mediated rejections can be distinguished. Usually, "R proceeds substantially as an acute cellular rejection whereas humoral rejection comprises only a smaller proportion of "R [ ]. Every single episode of an "R is a negative prognostic factor, increasing the risk for development of chronic allograft deterioration and worsening long-term graft survival [ ]. Interestingly, the impact of "R on chronic renal allograft failure as the main cause for death-censored graft-loss after kidney transplantation increases, whereas the severity of the episode itself is an independent risk factor [ -]. Therefore, early detection and rapid and effective treatment of "R are essential to preserve graft`s function. Clinically established screening methods such as elevated serum creatinine, occurrence or aggravation of proteinuria, oliguria, hypertension, graft tenderness, or peripheral edema, often lack the desired sensitivity and specificity for early diagnoses of "R. Hence,a compelling need for high sensitive

Role of nuclear medicine imaging in evaluation of complications following renal transplant

“…25 18 F-FDG PET might also assist in distinguishing acute rejection from other differential diagnoses such as cyclosporine toxicity and acute tubular necrosis in animal models. 26,27…”

Dynamic MRI-based computer aided diagnostic systems for early detection of kidney transplant rejection: A survey

“…Acute rejection, i.e., the immunological response of the human immune system to a foreign kidney, is the most important cause of renal dysfunction among other diagnostic possibilities. The incidence of renal rejection episodes depends on several factors, e.g., the organ (status), co-morbidities, medication and compliance [3]. Chronic allograft deterioration increases significantly with each acute rejection episode [4].…”

“…However, information gathered by CT to detect renal acute rejection is unspecific and the contrast agents used still are nephrotoxic. Therefore, currently CT has a limited role in diagnosing acute renal rejection [3]. Although magnetic resonance imaging (MRI) provides excellent morphological information that allowed advanced analysis of renal function, structural MRI lacks functional information.…”

A non-invasive diagnostic system for early assessment of acute renal transplant rejection.

“…Therefore, currently CT has a limited role in diagnosing acute renal rejection [64]. In contrast to these radionuclides and CTs, ultrasound (US) and MRI are the most popular imaging modalities used for the diagnosis of kidney diseases.…”