RESUMEN
OBJECTIVE: To describe special algorithm for the semi-autonomous 3-dimensional reconstruction of the pelvicalyceal system based on native computed tomography images of patients with upper urinary tract obstruction. MATERIALS AND METHODS: Fifty patients with renal colic fitting to inclusion criteria were enrolled. All patients underwent computed tomography urography to perform 3-dimensional reconstruction of the pelvicalyceal system on the affected size based on excretory phase representing "gold standard" and on native phase, which was performed via Medical Imaging Interaction Toolkit program updated with the described algorithm. Five urologists estimated their similarities and the potential use of non-contrast models for interventional planning. Contralateral non-distended pelvicalyceal system was reconstructed to evaluate the viability of the proposed technology in such cases. Surface areas of contrast and non-contrast models were compared. Distended pelvicalyceal system of 1 patient was used to reconstruct virtual endoscopic view. Obtained 3-dimensional noncontrast pelvicalyceal system models were analyzed by an engineer for suitability for 3-dimensional printing. RESULTS: The average surface area of contrast and non-contrast models was 3513 and 3371 mm2 , respectively (P=.0818). Non-contrast 3-dimensional reconstruction was possible with all distended pelvicalyceal systems and with 9 non-distended cases. Properties of non-contrast models were estimated as 4.3 out of 5. Obtained models were suitable for their intraluminal reconstruction and potential 3-dimensional printing. CONCLUSION: Described semi-autonomous approach allows for 3-dimensional reconstruction of dilated pelvicalyceal system based on non-contrast computed tomography images.