Comparison of ultrasonographic MicroFlow Imaging with contrast enhanced CT in the evaluation of renal mass

Abstract

Introduction MicroFlow Imaging (MFI) is a newer ultrasonography technique which enables to evaluate low velocity micro circulation such as organ perfusion or flow in small vascular beds. We tried to apply this technique in the evaluation of renal mass and compare ultrasonographic findings with CT enhancement. Materials and methods Between August 2018 to January 2019, fifty-four renal masses in forty-eight patients were retrospectively evaluated. All patients underwent MicroFlow Imaging (MFI) and color doppler imaging (CDI) using EPIQ 7 (Philips, the Netherlands) ultrasound machine and enhanced kidney CT scan including precontrast scan. The degree, distribution and shape of vascularity from MFI and CDI were analyzed. Degree of vascularity was ranged from 0 (absent) to 3 (profound). Distributions of vascularity were marked as peripheral, central and mixed. Shapes were marked as linear, branching and irregular. Incremental enhancement (IE) of CT was calculated by substraction of maximal measured Hounsfield unit (HU) from the HU of baseline precontrast scan. The degree of vascularity from MFI and CDI was correlated with IE of CT scan and mean IEs were compared among different group of the degree, distribution and shape of vascularity. Results The number of malignant lesions was thirty-two (30 renal cell carcinomas, 2 lymphomas) and the number of benign lesions was twelve (6 angiomyolipomas, 1 oncocytoma, 1 mixed epithelial and stromal tumor, 1 hemangioma, 3 simple cysts). All lesions were confirmed by histopathology (N= 35) or clinical follow-up over two years (N=7). Mean IE of benign solid (N=9) and malignant mass did not show statistical significance (p=0.412). Correlation coefficient (r) of IE between degree of vascularity from MFI and CDI were 0.6768 and 0.5164, respectively. Mean IEs according to different degree of vascularity from MFI and CDI were statistically significant (p Conclusion Comparing with CDI, MFI correlates better with contrast enhanced CT scan and predict tumor vascularity more sensitive and accurate.