Study of 320-Slice Dynamic Volume CT Perfusion in Different Pathologic Types of Kidney Tumor: Preliminary Results

Abstract

ObjectiveTo investigate microcirculatory differences between pathologic types of kidney tumor using 320-slice dynamic volume CT perfusion.MethodsPerfusion imaging with 320-slice dynamic volume CT was prospectively performed in 85 patients with pathologically proven clear cell renal cell carcinoma (RCC) (n = 66), papillary RCC (n = 7), chromophobe RCC (n = 5), angiomyolipoma (AML) with minimal fat (n = 7), or RCC (n = 78). Equivalent blood volume (Equiv BV), permeability surface-area product (PS; clearance/unit volume = permeability), and blood flow (BF) of tumor and normal renal cortex were measured and analyzed. Effective radiation dose was calculated.ResultsThere was a significant difference in all three parameters between tumor and normal renal cortex (P<0.001). Equiv BV was significantly different between RCC and AML with minimal fat (P = 0.038) and between clear cell RCC and AML with minimal fat (P<0.001). Mean Equiv BV and BF were significantly higher in clear cell RCC than in papillary RCC (P<0.001 for both) and mean Equiv BV was higher in clear cell RCC than in chromophobe RCC (P<0.001). The effective radiation dose of the CT perfusion protocol was 18.5 mSv.ConclusionPerfusion imaging using 320-slice dynamic volume CT can be used to evaluate hemodynamic features of the whole kidney and kidney tumors, which may be useful in the differential diagnosis of these four pathologic types of kidney tumor.

Risk Determination for Localised Renal Cell Carcinomas under 4 cm or Less: A Multi-institutional Analysis

“…These results could be explained by alterations of microvessel architecture in RCC, whereas oncocytomas, instead, appear to exhibit normal architecture, very close to the normal renal cortex. In fact, by evaluating a possible correlation of perfusion parameters with histological findings, particularly with microvessel density (MVD), a prognostic marker of RCC, we found a significant correlation between BF and BV and MVD ( < 0.01), suggesting that these CTp parameters may reflect blood vessels and then neoangiogenesis of RCCs, as also suggested by previous studies [10,24]. At ROC curve analysis, the difference between normal cortex and tumoural PS values yielded the best result with a cutoff greater than 2.5 mL/100 g/min with a sensitivity, specificity, and accuracy of 100%, 66.67%, and 95.92%, respectively, to predict RCCs.…”

“…To the best of our knowledge, this is the first study which has compared the same series of lesions by using both multiphasic CT and CTp. CTp allows the quantitative evaluation of a tissue perfusion whilst also optimising the acquisition protocol and has shown promising results in the oncologic field, even in RCC characterisation [10,21,22]. Like the recent studies, we found significant differences in PS and MTT values between malignant lesions (clear cell RCCs, papillary RCCs, and chromophobe RCCs) and the normal renal cortex ( < 0.001 and = 0.029, resp.…”

“…Like the recent studies, we found significant differences in PS and MTT values between malignant lesions (clear cell RCCs, papillary RCCs, and chromophobe RCCs) and the normal renal cortex ( < 0.001 and = 0.029, resp. ); however in our study BF and BV values were not significant; moreover, none of the CTp parameters evaluated in oncocytomas demonstrated significant differences from those of a normal renal cortex [10,23,24]. We also report significant lower values, in PS, MTT, and BF values ( < 0.001, = 0.01, and = 0.02, resp.)…”

“…No increased accuracy rate was obtained by considering both multiphase CT and CTp analysis. Previous studies tried to describe and differentiate the renal lesions according to the morphological criteria alone, which is often possible in large lesions, but which can be difficult for small lesions, or according to different multiphasic enhancement patterns upon CT examination, or using CTp parameters alone [10,[16][17][18][19][20]. One of the unique elements of our study is that it is the first which considers two different CT techniques in the evaluation of the same series of renal tumours; however it has some limitations.…”

“…Percutaneous biopsy could be a useful tool in dubious cases, but it is an invasive approach [8,9]. Recently, computed tomography perfusion (CTp), a functional tool which allows a quantitative evaluation of tissue perfusion through consecutive scans acquired during contrast media injection, showed promising results in the oncologic field, even in renal lesion characterisation [10]. It is based on a time-density curve developed by software, but its reliability is still being evaluated.…”