The diagnosis of adrenal disease includes localization diagnosis and qualitative diagnosis. Localization diagnosis is to clarify whether the lesion originates from the adrenal gland, while qualitative diagnosis is to clarify the nature of the adrenal lesion. In our clinic, we found that when reading spiral CT of adrenal diseases, if we follow step-by-step analysis of six features of spiral CT and combine with clinical endocrine examination, we can enhance the correct rate of qualitative diagnosis of adrenal diseases. (1) Location: Occupying lesions less than 3 cm are generally easier to identify as originating from the adrenal gland or peri-adrenal organs, but when the mass is large, it is often difficult to determine how the lesion originates from the adrenal gland. The author believes that the direction of displacement of adjacent organs and the location of the center of the mass can be helpful in identifying the origin of the lesion. Larger adrenal tumors generally grow and migrate forward, downward, to the right, and upward due to the obstructive effect of the ribs and muscles in the posterior abdominal wall. If the inferior vena cava, pancreatic and splenic veins are displaced anteriorly and the bulk of the mass is within the contour of the adrenal gland, this is most often suggestive of an adrenal tumor, whereas a posterior or internal displacement of the inferior vena cava should be considered a liver tumor. If the adrenal mass protrudes to the liver, careful analysis of its differences with liver tumor is necessary. When adrenal tumor protrudes to the liver, its edges are often compressed in an arc, the top of the mass is at an acute angle at the intersection with the liver, and the center of the tumor is located outside the liver, while no normal adrenal morphology can be seen at all levels of observation. In contrast, the tumor in the right lobe of the liver generally shifts backward, and the interfacial interface between the tumor and the suprarenal pole exists, or the interfacial interface is at an acute angle, which is different from the forward shift of the adrenal tumor. When the adrenal tumor pushes down the kidney, the morphology of renal pelvis and calyces generally does not change, which can be distinguished from renal parenchymal tumor. In this group, there is a patient with a huge occupying lesion in the right adrenal area with a maximum diameter of 25 cm, who was suspected of liver occupancy before surgery and confirmed as adrenocortical adenocarcinoma by postoperative pathology. Retrospective analysis of adjacent organs such as the direction of displacement of the inferior vena cava and the interface between the tip of the mass and the liver are consistent with the above characteristics. (2) Morphology: Most of the occurrences were round or ovoid, and a few were irregularly lobulated, but the latter often suggested the possibility of malignant lesions, and all the cortical adenocarcinomas (4 cases) and neuroblastomas (1 case) in this group were irregularly lobulated. (3) Size: To determine whether the adrenal gland is thickened, the thickness of the ipsilateral foot of the diaphragm is used as a criterion. The average thickness of the normal foot of the diaphragm is 3.5 mm, while limited nodular or diffuse thickening exceeding the ipsilateral foot of the diaphragm can be considered as hyperplasia. In general, adenomas are mostly less than 3 cm, with the two most prominent adenomas primary aldosteronism often less than 3 cm and Cushing’s syndrome often less than 5 cm, while adrenal hyperplasia is mostly 0. 6 to 3. 5 cm in size [6, 7]. Cortical adenocarcinoma tends to be larger, often larger than 6 cm, while pheochromocytoma tends to be of medium size, with more than half in the range of 3 to 6 cm. (4) Density: adenoma and hyperplasia are homogeneous in texture with CT values of 15 to 25 HU, while pheochromocytoma and adenocarcinoma are prone to hemorrhage and necrosis liquefaction resulting in inhomogeneous density. For example, the density of cortical adenoma is low due to the lipid-like substance in the lesion. In contrast, lipomas or medullary lipomas have very low CT values, below -10Hu, resembling adipose tissue [8]. Calcifications and intra-mass cystic changes are seen in cortical adenocarcinoma and larger pheochromocytomas, especially the former. (5) Whether or not to enhance: adrenal adenomas show mild enhancement, while pheochromocytomas can be significantly enhanced on CT enhancement due to the rich blood supply. Also the nature of adrenal tumors can be determined by comparing the CT values of different tumors in various periods as well as by calculation [9]. In the arterial phase of adrenal adenoma, the contrast agent enters the parenchyma of the tumor very quickly, resulting in a better enhancement of the parenchyma, whereas in the venous phase, the contrast agent is drained from the parenchyma of the tumor very quickly, resulting in less enhancement of the parenchyma of the tumor than in the arterial phase. Adrenal adenomas are significantly earlier to the discharge of contrast than adrenal metastases, so a definite CT value may be obtained by delayed CT scan. CT values of adrenal tumors obtained after 10-15 minutes delay of enhanced CT scan are below 30Hu, then these lesions can be diagnosed as benign with certainty. However, in adrenal metastatic carcinoma the tumor enhances in a significantly different manner than in adenoma. In both the arterial and venous phases of the enhancement scan, the contrast agent is a gradual change into the tumor, and the tumor parenchyma enhances to a greater degree in the venous phase than in the arterial phase, suggesting that more contrast agent enters the tumor parenchyma in the venous phase than in the arterial phase. In other words, adrenal adenoma is a fast-in and fast-out change of contrast agent during enhancement, while adrenal malignant metastases are a slow-in and slow-out change, and the contrast agent is retained in the metastatic tumor parenchyma for a longer period of time [10, 11]. (6) Margin: the morphology of tumor margin suggests the benign and malignant nature of the tumor. Most benign tumors have smooth and regular margins, and a few have mild lobulation; malignant tumors have irregular lobulated margins due to uneven tumor growth rate, and unclear margins with adjacent tissues indicate infiltration into surrounding tissues. However, ganglioneuroblastoma, as a benign lesion, often has burr-like or star-shaped radiating margins. (7) The condition of the contralateral adrenal gland also reflects the nature of the adrenal occupancy. Most contralateral adrenal glands are normal in morphology and size, but there is also atrophy or hyperplasia. Contralateral adrenal atrophy is mainly seen in patients with Cushing’s syndrome, where ipsilateral and contralateral adrenal atrophic changes due to reduced feedback ACTH levels are manifested by smaller adrenal glands and slender lateral limbs [12], whereas in primary aldosteronism there are no atrophic lesions in either the ipsilateral or contralateral adrenal glands, based on which two adenomas of similar size can be differentiated. Adrenocortical carcinoma can also have atrophic lesions in the contralateral adrenal gland, but its tumors are often larger and tend to have hypodense foci or abnormal signals in the center due to necrosis. The qualitative diagnosis of adrenal gland mainly relies on endocrine examination, but there are some characteristic manifestations of adrenal gland diseases in spiral CT, which have important application value for the qualitative diagnosis of adrenal gland diseases, and improving the understanding of spiral CT features of adrenal gland diseases has guiding significance for clinical diagnosis.