Table 2.

Imaging features of solid renal masses [48].

Renal Lesion	CT	MRI
Clear Cell carcinoma	Heterogeneous mass due to necrotic, cystic and hemorrhagic areas; Strong contrast enhancement in corticomedullary and contrast wash out during nephrographic phases	Hyper vascular lesion; Hyperintense on T2WI and hypo- to isointense on T1WI; Heterogeneous avid enhancement than the rest of RCC types on contrast administration; Microscopic fat in 60% of cases; CSI: >25% signal loss on opposed phase relative to in-phase imaging due to fat content; Tumor pseudo capsule: hypointense rim on T1WI and T2WI.
Chromophobe carcinoma	Homogeneous to heterogeneous mass	Well circumscribed homogeneous tumors; Iso- to hypointense lesion son T2WI; The lesion enhances greater than papillary but lesser than clear cell renal carcinoma; Central stellate scar in 30–40% of cases; Spoke-wheel enhancement can be observed; Segmental enhancement inversion may be noticed; Calcifications in 38% of cases.
Papillary carcinoma	Tumors < 3 cm: homogeneous; Tumors ≥ 4 cm: Heterogeneous due to necrosis; Subtle contrast enhancement than ccRCC; Absent enhancement can be observed in 25% of patients;	Well-circumscribed homogeneous mass; Usually <3 cm; Mass: hypointense on T2WI which enhance progressively with contrast administration; CSI: signal loss on in-phase relative to opposed phase imaging due to hemosiderin deposition; Fibrous capsule: hypointense on T1WI & T2WI;
Renal NET	Heterogeneous solid tumor with cystic component as well; Minimal enhancement on contrast administration; Octreotide scintigraphy: High affinity for somatostatin in 87% of patients.	Heterogeneous signal intensity on T1 and T2WI with areas of high signal intensity on T1WI due to hemorrhage; The mass enhances with contrast administration