# Dual-Energy CT Applications in Urological Diseases
## 4 DECT Clinical Applications
### Study of Renal Lesions
\begin{table}
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**Author** & **Investigated Pathology** & **N° of Patients** & **Gold Standard** & **Acquisition Phase in DECT** & **Main Results** \\ \hline \multirow{4}{*}{[PERSON] et al. [53]} & Ultrasound-based suspicion of a renal mass & \multirow{4}{*}{202} & \multirow{4}{*}{Histopathology} & \multirow{4}{*}{Nephrographic phase} & -96.0\% patients with malignancy and 93.2\% without malignancy were correctly identified \\  & & & & & -’The omission of the true unenhanced phase led to a 48.9 \(\pm\) 70.5\% dose reduction. \\ \hline \multirow{4}{*}{[PERSON] et al. [54]} & \multirow{4}{*}{Renal lesions} & \multirow{4}{*}{69} & \multirow{4}{*}{**Simple cysts**: all distinct features of a simple cyst on both CT and MR} & \multirow{4}{*}{
\begin{tabular}{} \end{tabular} } & -The pooled diagnostic confidence scores for the three readers were comparable for the DECT and MRI scans (pooled DECT mean = 47, SD; 0.48 vs pooled MRI mean = 4.7, SD; 0.51, \(p\)-value 0.96) \\  & & & & 0.48 vs pooled MRI mean = 4.7, SD; 0.51, \(p\)-value 0.96) \\ \cline{1-1}  & & & & -’The inter-indexed agreement was almost perfect for DECT and MRI (kappa 0.8–1) \\ \cline{1-1}  & & & & (kappa 0.8–1) \\ \cline{1-1}  & & & & -’Comparable diagnostic accuracy between single energy CT, DECT, and MRI (\(p\)-value \(>\) 0.05). \\ \hline \end{tabular}
\end{table} 
Table 2: Characteristics and results on the studies dealing with renal lesion characterization with DECT. Figure 8: (**a**) Left renal lesion with prevalent fat tissue density, but with inhomogeneous content; (**b**) the color-coded overlay-iodine map demonstrates the absence of intralesional contrast enhancement, confirmed by the iodine analysis (**c**). The lesion was characterized as an angiomyolipoma. The curve of angiomyolipoma (blue) shows a reduction in the attenuation values at lower energies with attenuation values in line with that of the fat tissue (green). HU = Hounsfield Units. \begin{table}
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**Author** & **Investigated Pathology** & **N\({}^{*}\) of Patients** & **Gold Standard** & **Acquisition Phase in DECT** & **Main Results** \\ \hline [PERSON] et al. [55] & Renal masses & 24 & Histopathology & Corticomedullary phase (CMP) and late nephrographic phase (LNP) & -No significant difference in diagnostic accuracy comparing subjective enhancement by MRI and DECT iodine map. \\ \hline [PERSON] et al. [68] & Capillary renal-cell carcinoma (pRCC) & 1 & Histopathology & Not specified & -iodine maps allow for their accurate characterization as solid masses. \\ \hline [PERSON] et al. [58] & Renal masses & 110 & Histopathology, contrast-enhanced US, follow-up CT & Nephrographic phase DET & -in all but three patients, radiologists accepted virtual non-contrast images as a replacement for true non-contrast images. \\ \hline  & & & & -Men dose reduction by omitting the true non-contrast scan was 35.05\%. \\ \hline  & & & & -For differentiating between solid and benign cystic lesions, the specificity and accuracy of all lesions and lesions \(<1.5\) cm were statistically lower in iodine image than in linearly blended images, for lesions \(1.5\) cm, they were not statistically different. & -For differentiating between solid and benign cystic lesions, the specificity and accuracy of all lesions and lesions \(<1.5\) cm were statistically lower in iodine image than in linearly blended images for lesions \(1.5\) cm, they were not statistically different. \\ [PERSON] et al. [61] & Hyperdense renal lesions & 79 & In patients who underwent surgical resection or biopsy, histopathological reproorts were used as the reference standard. If histopathology was not confirmed follow-up imaging was used to make a final diagnosis. & -Virtual non-contrast and true unenhanced evaluation to identify complex cystic renal masses was judged according to \(9\%\%\) of cases. \\ [PERSON] et al.