Normal Pancreas Graft Appearance in Magnetic Resonance Diffusion Tensor Imaging (DTI)

Application of Diffusion Kurtosis Imaging and Blood Oxygen Level-Dependent Magnetic Resonance Imaging in Kidney Injury Associated with ANCA-Associated Vasculitis

OBJECTIVE

Functional magnetic resonance imaging (fMRI) has been applied to assess the microstructure of the kidney. However, it is not clear whether fMRI could be used in the field of kidney injury in patients with Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

This study included 20 patients with AAV. Diffusion kurtosis imaging (DKI) and blood oxygen level-dependent (BOLD) scanning of the kidneys were performed in AAV patients and healthy controls. The mean kurtosis (MK), mean diffusivity (MD), and fractional anisotropy (FA) parameters of DKI, the R2* parameter of BOLD, and clinical data were further analyzed.

RESULTS

In AAV patients, the cortex exhibited lower MD but higher R2* values compared to the healthy controls. Medullary MK values were elevated in AAV patients. Renal medullary MK values showed a positive correlation with serum creatinine levels and negative correlations with hemoglobin levels and estimated glomerular filtration rate. To assess renal injury in AAV patients, AUC values for MK, MD, FA, and R2* in the cortex were 0.66, 0.67, 0.57, and 0.55, respectively, and those in the medulla were 0.81, 0.77, 0.61, and 0.53, respectively.

CONCLUSIONS

Significant differences in DKI and BOLD MRI parameters were observed between AAV patients with kidney injuries and the healthy controls. The medullary MK value in DKI may be a noninvasive marker for assessing the severity of kidney injury in AAV patients.

Vascular Complications After Simultaneous Pancreas and Kidney Transplantation: A Case Report

A 51-year-old patient with type I diabetes and end-stage renal disease was qualified for a simultaneous kidney and pancreas transplant. The procedure was performed in a typical manner: arterial anastomosis to the right common iliac artery, the graft's portal vein with inferior vena cava, and side-to-side duodenal intestinal anastomosis. The kidney was implanted retroperitoneally. Six months after the transplant, the patient reported pain in the right lower abdomen, and imaging examinations revealed arterial anastomosis. Reconstruction of the right common iliac artery was performed with a Gore-Tex prosthesis and the pancreatic artery reanastomosed to the right external iliac artery. After the surgery, the function of the transplanted pancreas deteriorated, the level of C-peptide was decreased, and the patient required low doses of insulin. After another 8 months, the imaging studies revealed an aneurysm located in the bifurcation of the aorta up to the anastomosis of the pancreatic graft artery with the iliac artery. The patient was qualified for the implantation of an endovascular of 2 prosthesis, which improved the graft's function. After another 2 months, the presence of an aneurysm at the endovascular prosthesis was found again. The patient was requalified for endovascular prosthesis implantation. Currently, there is no aneurysm but the function of the pancreas graft is impaired, though the kidney graft function is good. Patients after simultaneous kidney and pancreas transplant are a group of patients with an increased risk of vascular complications. Treatment should take place in a multidisciplinary center.

The course of Covid-19 infection in patients after pancreas and kidney transplantation – a single - centre observation

Solid graft recipients are at an increased risk of serious complications and death. Out of 130 outpatient recipients of pancreas grafts at our Clinic, 20 patients (15.73%) had a confirmed severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2). Each patient had a different course of the disease, and the forms of infection varied from mild to severe and lethal. According to recommendations, after confirmation of the infection, mycophenolate mofetil was withdrawn and the immunosuppression was based on steroids and a calcineurin inhibitor. In this study, we performed an analysis of the course of COVID-19 infection in patients after pancreatic transplantation. Twenty pancreas recipients were confirmed to have COVID-19 infections; 4 of whom required hospitalization owing to severe complications. Patients reported weakness, excessive intensity of fatigue, shortness of breath with exertion, cough, and periodically increased temperature. Weakness and fatigue persisted in these patients for about 6 weeks. In 2 patients there was a need for oxygen supplementation and empirical antibiotic. Mortality was 5%, and there was 1 graftectomy. Deterioration of either kidney or pancreas graft were not observed in any other patients.

The course of SARS-CoV-2 infection in solid graft recipients is similar to that of the rest of the population. Because of immunosuppression, recipients were accustomed to avoiding crowds and complying with obligations to wear masks.