CT is a widespread technique in cryoablated renal tumors monitoring allowing morphologic imaging of the kidney during several enhancement phases, in a tri-phases acquisition. The multiphasic acquisition with the new MSCTs provides find more a representation of each component of contrast enhancement (intravascular and extravascular).
Therefore, the use of functional imaging techniques to assess tissue perfusion and permeability allows a more deeply angiogenesis process analysis of the tumor with functional informations that cannot be appreciated from qualitative or quantitative (UH) analysis of static tri-phase contrast enhanced images. Furthermore it implies a margining of factors other than angiogenesis that may influence the quantification of contrast enhancement (e.g. amount of contrast agent, patient weight, cardiac output) . The advent of multislice CT scanner with new perfusion software programs creates a unique opportunity for imaging as a reproducible method to assess, click here in vivo
and more deeply than the qualitative evaluation of contrast enhancement, tumor vascularity for monitoring and possibly predicting clinical response to cryotherapy. Otherwise, the common imaging criteria of lesion shrinkage to assess tumor response to cryotherapy may not be the ideal technique of detecting in vivo activity and clinical outcome of ablation and may be implemented with functional imaging parameters from tumor ablated area to obtain much reliable post-treatment informations. RCC is a highly vascularised tumor with verified correlation between contrast enhancement measures and microvessel density  and between its quantification and prognostic information in early-stage of RCC [15, 19]. It is well known that neoangiogenesis is a crucial factor oxyclozanide for tumor
cell growth and metastatic potential in cancer disease, inversely related with patient survival . This process is characterized by increased microvessel density and microanatomical changes of new vessels related to fenestration of the basement membrane resulting in anomalous tissue perfusion compared to normal parenchyma and an increase in the permeability to large molecules in blood. Considering that tumor neoangiogenesis induces pathophysiological abnormalities to the hemodynamic environment surrounding the tumor, anomalous tissue perfusion can be qualitatively and quantitative expressed in time-enhancement curves and in colour map measurements in a perfusional contrast-enhanced study [31, 34].