MRI-derived markers for predicting a decline in renal function in patients with autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) constitutes the fourth cause of end-stage renal disease in Europe. The course of the disease varies widely among patients with ADPKD. Due to the emergence of new possibilities of pharmacotherapy, it has become crucial to identify the group of patients with the fastest rate and risk of disease progression. This particular group of patients will benefit most from the therapy and they are the best candidates for clinical trials. At the early stages of ADPKD typical markers of severity and progression of the disease remain unchanged in contrast to the kidney volume, which increases continuously in an exponential way. Therefore, the use of height-adjusted total kidney volume as a biomarker should become a mandatory diagnostic option. Also, quantitative MRI techniques are promising biomarkers for the evaluation of disease severity and could provide additional insights into its course.

Application of Total Kidney Volume and Its Predictive Value in Assessment of Kidney Transplant Waitlist Candidates With Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most prevalent causes of kidney transplantation (KTx) worldwide. About 40% of ADPKD patients require peritransplant native kidney nephrectomy (NKN). The decision regarding qualification for NKN usually relies on the surgeon's expertise. Currently used qualification criteria are subjective and incomparable between clinical centers. There is a need to identify the indications for NKN by applying radiologically based methods to the decision-making process. AIM: To assess the usefulness of radiologic parameters in the qualification process of ADPKD waitlist candidates for the NKN procedure. METHOD: A retrospective, observational study in a cohort of ADPKD patients in a single institution was conducted. The study included the participation of waitlist candidates and kidney transplant recipients with computed tomography (CT) or magnetic resonance imaging (MRI) obtained in the peritransplant period. The correlation of imaging-based measurements with the results of clinical qualification for the NKN procedure was assessed. RESULTS: In the years 2012 to 2019, 19 patients completed the inclusion criteria. Total kidney volume (TKV) values were statistically more significant in the NKN group (n = 10) than in the non-NKN group (n = 9), with medians of 3351 mL and 1654 mL, respectively (P = .016). There were no significant differences between the groups in terms of the ratio of complex cyst volume to TKV, with the NKN group having a ratio of 19.2% and the non-NKN group 15.6% (P = .095). Venous compression was found only in the NKN group (n = 2). CONCLUSIONS: TKV highly correlates with the results of clinical qualification for NKN. Radiologic assessment enables the detection of complicated cysts or clinically silent states of venous compression. Pretransplant imaging should be routinely obtained.

Computation of the Texture Features on T2-Weighted Images as a Novel Method to Assess the Function of the Transplanted Kidney: Primary Research.

Texture in medical images describes the internal structure of human tissues or organs. We hypothesize that textural analysis (TA) could be applied to assess renal function after kidney transplantation (KTx). This preliminary study aims to find a statistical difference between texture features in transplanted kidneys with different placement of region of interest (ROI). Also, we aimed at comparing results of TA with transplanted kidney function. For analysis, we used 9 retrospective examinations in patients with a transplanted kidney. All patients underwent a diagnostic magnetic resonance imaging (MRI) scan, including T2-weighted images. All MRI acquisition was performed using a 1.5T MRI (MAGNETOM Aera, Siemens Healthineers AG, Erlangen, Germany). Examinations were performed from indications other than KTx and in various times after KTx. We found an association between the texture parameters and the estimated glomerular filtration rate (4p estimate formula: Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) and between texture parameters and creatinine in ROI location in the cortex. Our findings make TA a promising tool for the assessment of the function of the transplanted kidney. However, the effect of binning, ROI size, and placement of ROI in the organ are yet to be determined and need further study.