MDCT imaging following nephrectomy for renal cell carcinoma: Protocol optimization and patterns of tumor recurrence

Figure 9 Right adrenal mass in a 54-year-old male patient status post left nephrectomy four years prior to the exam. A: Non-contrast; B: Arterial; C: Venous phase; D: Delayed phase. On non-contrast the lesion measures 33 HU; on arterial phase the lesion measures 180 HU; on venous phase the lesion measures 101 HU; on delayed phase the lesion measures 57 HU (arrow, right adrenal mass). Absolute washout is 65% and the relative washout is 44%. By washout, this lesion is compatible with adenoma. However, the hypervascularity of the lesion (> 100 HU) is atypical for adenoma, suggesting metastasis.