Contraindication to both iodinated CT and gadolinium-based MR intravenous contrast. Initial imaging. Arteriography Kidney Cross-sectional imaging has replaced arteriography for the evaluation of indeterminate renal masses. There is no relevant literature regarding the use of arteriography in the evaluation of indeterminate renal masses. Arteriography typically requires IV administration of iodinated contrast. CT Abdomen Iodinated CT contrast is contraindicated in some patients with severe allergy to the CT contrast or patients who are at high risk for contrast-induced nephropathy. For more details, please refer to the ACR Manual on Contrast Media [71]. The inability to utilize IV contrast to evaluate a renal mass markedly limits whether it can be classified as benign or malignant on CT, but it does provide some information if calcifications, nodules, or septations are visible. Homogenous renal masses measuring <20 HU or >70 HU [1,2] or lesions containing macroscopic fat can be characterized as benign lesions, but all other small lesions cannot be characterized using CT without IV contrast. Large lesions with calcifications and necrosis may not need further characterization, but detection of venous invasion and metastases is also limited. Indeterminate Renal Mass CTU There is no relevant literature regarding the use of CTU in the evaluation of indeterminate renal masses. MRI Abdomen Because of the risk for nephrogenic systemic fibrosis [72], certain gadolinium-based contrast agents may be contraindicated in patients with renal failure. Another contraindication is severe allergy to gadolinium agents. For more details, please refer to the ACR Manual on Contrast Media [71]. In the absence of contrast, unenhanced MRI has some advantages over unenhanced CT in the characterization of renal masses. Simple cystic lesions or even those with thin septations can often be characterized on noncontrast T2-weighted imaging based on their homogeneous and very high T2 signal intensity.
Indeterminate Renal Mass. Contraindication to both iodinated CT and gadolinium-based MR intravenous contrast. Initial imaging. Arteriography Kidney Cross-sectional imaging has replaced arteriography for the evaluation of indeterminate renal masses. There is no relevant literature regarding the use of arteriography in the evaluation of indeterminate renal masses. Arteriography typically requires IV administration of iodinated contrast. CT Abdomen Iodinated CT contrast is contraindicated in some patients with severe allergy to the CT contrast or patients who are at high risk for contrast-induced nephropathy. For more details, please refer to the ACR Manual on Contrast Media [71]. The inability to utilize IV contrast to evaluate a renal mass markedly limits whether it can be classified as benign or malignant on CT, but it does provide some information if calcifications, nodules, or septations are visible. Homogenous renal masses measuring <20 HU or >70 HU [1,2] or lesions containing macroscopic fat can be characterized as benign lesions, but all other small lesions cannot be characterized using CT without IV contrast. Large lesions with calcifications and necrosis may not need further characterization, but detection of venous invasion and metastases is also limited. Indeterminate Renal Mass CTU There is no relevant literature regarding the use of CTU in the evaluation of indeterminate renal masses. MRI Abdomen Because of the risk for nephrogenic systemic fibrosis [72], certain gadolinium-based contrast agents may be contraindicated in patients with renal failure. Another contraindication is severe allergy to gadolinium agents. For more details, please refer to the ACR Manual on Contrast Media [71]. In the absence of contrast, unenhanced MRI has some advantages over unenhanced CT in the characterization of renal masses. Simple cystic lesions or even those with thin septations can often be characterized on noncontrast T2-weighted imaging based on their homogeneous and very high T2 signal intensity.