Contrast-enhanced CT texture analysis for the prediction of delayed graft function following kidney transplantation from cadaveric donors.

OBJECTIVE: Delayed graft function (DGF) is a common complication after transplantation of deceased donor kidneys. The aim of this study was to investigate the feasibility of using computed tomography texture analysis (CT-TA) of the donor kidney to predict delayed graft function (DGF) following kidney transplantation from cadaveric donors. MATERIALS AND METHODS: We made a retrospective review of all consecutive DBD and DCD kidney donors admitted to our institution and their corresponding KTRs between December 2014 and January 2019. We extracted 15 image features from unenhanced CT and contrast-enhanced CT corresponding to first order and second order Haralick textural features. Predictors of DGF were evaluated by univariable and multivariable analysis. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (AUC) to predict DGF was calculated for the predictors. RESULTS: A total of 115 patients were included in the study. DGF occurred in 15 patients (13%). Recipient body mass index (BMI) (P=0.003) and Skewness (P=0.05) represented independent predictors in the multivariate model. The combination of both clinical and textural features in a bivariate model reached a ROC-AUC of 0.79 (95% CI: 0.64-0.94) in predicting the probability of DGF. CONCLUSION: Results from this preliminary study suggest that CT texture analysis might be a promising quantitative imaging tool to help physician predict DFG after kidney transplantation from cadaveric donors. LEVEL OF EVIDENCE: 4/5.

Exercise testing criteria to diagnose lower extremity peripheral artery disease assessed by computed-tomography angiography.

BACKGROUND: The sensitivity and specificity of exercise testing have never been studied simultaneously against an objective quantification of arterial stenosis. Aims were to define the sensitivity and specificity of several exercise tests to detect peripheral artery disease (PAD), and to assess whether or not defined criteria defined in patients suspected of having a PAD show a difference dependent on the resting ABI. METHODS: In this prospective study, consecutive patients with exertional limb pain referred to our vascular center were included. All patients had an ABI, a treadmill exercise-oximetry test, a second treadmill test (both 10% slope; 3.2km/h speed) with post-exercise pressures, and a computed-tomography-angiography (CTA). The receiver-operating-characteristic curve was used to define a cut-off point corresponding to the best area under the curve (AUC; [CI95%]) to detect arterial stenosis ≥50% as determined by the CTA. RESULTS: Sixty-three patients (61+/-11 years-old) were included. Similar AUCs from 0.72[0.63-0.79] to 0.83[0.75-0.89] were found for the different tests in the overall population. To detect arterial stenosis ≥50%, cut-off values of ABI, post-exercise ABI, post-exercise ABI decrease, post-exercise ankle pressure decrease, and distal delta from rest oxygen pressure (DROP) index were ≤0.91, ≤0.52, ≥43%, ≥20mmHg and ≤-15mmHg, respectively (p<0.01). In the subset of patients with an ABI >0.91, cut-off values of post-exercise ABI decrease (AUC = 0.67[0.53-0.78]), and DROP (AUC = 0.67[0.53-0.78]) were ≥18.5%, and ≤-15mmHg respectively (p<0.05). CONCLUSION: Resting ABI is as accurate as exercise testing in patients with exertional limb pain. Specific exercise testing cut-off values should be used in patients with normal ABI to diagnose PAD.