The Value of Dual-Phase Enhancement CT as a Predictor of the Preoperative Preparation of Adrenal Pheochromocytoma

The purpose of this study was to evaluate the function of adrenal pheochromocytoma with the value of dual-phase enhancement computed tomography (CT) and to guide the preoperative preparation of adrenal pheochromocytoma. From June 2009 to December 2015, the patients with a diagnosis of pheochromocytoma were divided into 2 groups according to the length of preparation time (group 1, ≤2 weeks; group 2, >2 weeks). Two experienced radiologists measured adrenal lesion attenuation from dual-phase, contrast-enhanced CT examinations. Student t-test analysis was performed to compare arterial and venous phase enhancement levels and the maximum increased enhancement CT value. There were 31 cases of pheochromocytoma that were accepted into the study: 13 cases in group 1 and 18 cases in group 2. At contrast-enhanced CT, the mean arterial enhancement and venous enhancement of pheochromocytoma were 74 ± 20 Hounsfield units (HU; range, 50–107 HU) and 72 ± 18 HU (range, 44–109 HU), respectively, in group 1, which were significantly less than those in group 2, with a mean of 101 ± 26 HU (range, 64–138 HU) and 100 ± 22 HU (range, 61–131 HU; P < 0.05). The average maximum increased attenuation at enhancement CT in group 1 was 41 ± 12 HU (range, 24–62 HU), significantly less than that in group 2, with a mean of 62 ± 22 HU (range, 26-102 HU; P < 0.05). The preparation time was related to the absolute enhancement level, especially with the maximum increased attenuation of pheochromocytoma at enhanced CT. More preparation time before surgery was needed if the maximum enhancement level during arterial phase and venous phase was greater than 109 HU and the maximum increased attenuation was greater than 62 HU.