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Objective: The objectives of our study of patients with primary hyperaldosteronism (Conn's syndrome) were to determine whether the adrenal glands are larger in patients with bilateral adrenal hyperplasia than in those with aldosterone-producing adenomas or in healthy control subjects; and whether a CT criterion based on adrenal gland size can be developed to positively diagnose bilateral adrenal hyperplasia., Materials and Methods: A retrospective study of CT scans of 28 patients with primary hyperaldosteronism was performed. The means of two observers' measurements of adrenal gland size were recorded and compared with published normal values. In addition, a radiologist experienced in adrenal imaging and unaware of the cause of the primary hyperaldosteronism diagnosed either bilateral adrenal hyperplasia or aldosterone-producing adenoma by visual inspection., Results: The adrenal glands in patients with bilateral adrenal hyperplasia were significantly (p < 0.05) larger than those in patients with aldosterone-producing adenoma or in healthy control subjects. A sensitivity of 100% was achieved when a mean limb width of greater than 3 mm was used to diagnose bilateral adrenal hyperplasia, and a specificity of 100% was achieved when the mean limb width was 5 mm or greater. Receiver operating characteristic curve analysis showed that the overall performance of the radiologist and the mean adrenal limb width in detecting bilateral adrenal hyperplasia were equivalent., Conclusion: In patients with primary hyperaldosteronism, adrenal limb measurements on CT can aid in differentiating bilateral adrenal hyperplasia from aldosterone-producing adenoma because the adrenal glands in bilateral adrenal hyperplasia are larger.

Objective: The purpose of this study was to evaluate the efficacy of transcatheter arterial ablation (TAA) of aldosteronomas with high-concentration ethanol (HCE)., Materials and Methods: From August 1992 to August 1995, 18 patients with unilateral aldosteronoma, three men and 15 women, 28-65 years old, were treated by TAA with HCE. A single dose (0.2-7.0 ml) of HCE was selectively infused into the feeding arterial branches of the aldosteronoma using a microcatheter and the coaxial technique. The 18 patients underwent 31 TAA procedures., Results: Ablation of the aldosteronoma was monitored by measuring plasma levels of aldosterone and was successful in 15 (83%) of 18 patients. The remaining three patients underwent surgery because results of TAA were insufficient. The destructive effect of ablation by HCE has persisted for 7-38 months (mean, 20 months) in 14 patients. Although one patient had recurrence of symptoms 15 months after the initial TAA, normalization of plasma levels of aldosterone continued for 3 months after TAA was repeated. No severe complications occurred in any of the 18 patients. However, back pain (18 of 18), slight fever (nine of 18), pleural effusion (two of 18), and labile changes in blood pressure (one of 18) were noted in patients 1-7 days after the procedure., Conclusion: TAA of aldosteronoma with HCE is an alternative to open adrenalectomy.

Objective: The most common cause of primary aldosteronism is a small aldosterone-secreting adrenal adenoma. With improvements in CT technology, smaller adrenal lesions can now be detected. We reviewed our experience with 29 patients with primary aldosteronism to assess the sensitivity of CT in detecting aldosterone-secreting adenomas., Materials and Methods: The records of all patients with biochemically proved Conn's syndrome who were referred for adrenal CT between 1982 and 1991 were reviewed. The CT examinations of each of these 29 patients were reviewed for evidence of hyperplasia or an adenoma. The interpretations were correlated with subsequent adrenal venous sampling (20 patients) or surgery (17 patients)., Results: Fourteen of 17 aldosteronomas were detected on CT scans (sensitivity, 82%). Adrenal tumors were not seen on CT scans in any of the 12 patients with hyperplasia, although the glands appeared diffusely enlarged in only seven of these patients. In no case was an adrenal tumor seen on CT scans that was not found at surgery (positive predictive value, 100%)., Conclusion: If CT scans of patients with Conn's syndrome show a focal mass, ipsilateral adrenalectomy can be performed with the expectation of cure. If no mass is found, adrenal venous sampling can be used to detect an adenoma not shown on CT.

Twenty patients with primary hyperaldosteronism had endocrinologic and radiologic studies to distinguish aldosterone-producing adenoma from idiopathic hyperaldosteronism due to bilateral micro- or macronodular hyperplasia of the adrenal cortex. In addition to examination for changes in the plasma level of aldosterone associated with postural changes and measurement of the plasma level of 18-hydroxycorticosterone, all 20 patients had CT examination of the adrenal glands. In three patients with normal adrenal glands on CT and three patients with CT evidence of two solitary nodules, one in each adrenal gland, a diagnosis of idiopathic hyperaldosteronism was confirmed by endocrinologic findings (five patients) or 131I-6 beta-iodomethyl-19-norcholesterol (NP-59) adrenal scintigraphy (one patient). In nine patients with a solitary adrenal nodule on CT, a diagnosis of aldosterone-producing adenoma was confirmed by surgery (seven patients) or hormone sampling via the adrenal veins (two patients). However, in three patients with a solitary adrenal nodule on CT, a diagnosis of idiopathic hyperaldosteronism was suggested by endocrinologic findings (three patients) and confirmed by the results of NP-59 scintigraphy (two patients) or adrenal venous sampling (one patient). In addition, in two patients with CT evidence of three adrenal nodules (two in one gland, one in contralateral gland), a diagnosis of aldosterone-producing adenoma was suggested by endocrinologic findings in both patients and confirmed by surgery in one. Although high-resolution CT is highly accurate for the detection of aldosterone-producing adenoma, significant diagnostic errors can occur in patients with primary hyperaldosteronism if CT findings are not correlated with results of endocrinologic studies.

The CT values of adrenal tumors were evaluated in 36 patients to determine the frequency and significance of negative CT values. Twenty-seven patients had adrenocortical adenomas (13 had primary aldosteronism, 12 had Cushing syndrome, and two had nonhyperfunctioning adenoma), one had adrenocortical carcinoma, and eight had pheochromocytomas. The CT values in primary aldosteronism (mean, 1.8 +/- 9.9 H) were lower than those in Cushing syndrome (27.6 +/- 12.0 H) and pheochromocytoma (35.9 +/- 9.8 H). Six adrenocortical adenomas had homogeneous, low CT attenuation, with CT values ranging from -20 to -0.4 H. Four of these had primary aldosteronism, one had Cushing syndrome, and one had nonhyperfunctioning adenoma. Our results suggest that adrenal tumors with homogeneous, slightly negative CT attenuation are likely to be adrenocortical adenomas, mainly primary aldosteronism and nonhyperfunctioning adenomas. This finding may be especially useful in diagnosing nonhyperfunctioning adenoma.

Autonomous hypersecretion of aldosterone (primary hyperaldosteronism) is caused by either hyperplasia (usually bilateral) or an adenoma (frequently unilateral) of the adrenal cortex. Systemic hypertension due to an aldosteronoma is a potentially curable condition through surgical extirpation of the offending organ. In our experience with 37 patients clinically suspected to have primary hyperaldosteronism, radiological methods contributed significantly in preoperative diagnosis. These included (1) selective bilateral adrenal vein catheterization and blood sample collection, (2) adrenal venography, and (3) radioisotope adrenal scan. Unilateral hyperfunction could be accurately detected by the aldosterone assays from the collected samples. When adrenal venography was technically satisfactory, a nodule or aggregate of nodules measuring at least 7 mm and located on the margin of the gland or 1.5 cm or more in diameter when located in the center of the gland were readily identified. Enlarged adrenal gland on venography, in itself, was not a dependable index of a hyperfunctioning gland. Presence of a higher uptake on one side on the radioisotope adrenal scan did not always indicate the hyperfunctioning gland, but lack of lateralization of adrenal hyperfunction was more accurately predicted on the radioisotope scan than by venography. Four histopathological patterns were recognized in the surgically removed adrenal glands, but no correlation between these patterns and clinical behavior or postoperative course was found.

A series of 63 patients with suspected adrenal disease was evaluated by computed tomography (CT). In 15 additional patients CT diagnosed unsuspected adrenal disease. The CT results were correlated with surgical, postmortem, or compelling clinical data. In those patients with adequate visualization of both adrenals, CT correctly identified all adrenal masses subsequently proven at surgery or postmortem examination. CT accurately predicted the presence or absence of a unilateral adrenal neoplasm in patients with Cushing's syndrome and primary aldosteronism. Unsuspected primary or metastatic neoplasms of the adrenals were occasionally detected in patients scanned for other reasons. CT is a safe and accurate method of evaluating patients with suspected adrenal disease.

Twenty-nine patients with primary hyperaldosteronism were evaluated with computed tomography (CT), adrenal venous sampling, and adrenal venography. Twenty-three patients had aldosteronomas and six had bilateral adrenocortical hyperplasia. Sixteen (70%) of the adenomas were accurately located by CT. All nodules of 1.5 cm or larger diameter and 50% of nodules 1.0-1.4 cm in diameter were demonstrated. Nodules of less than 1.0 cm in diameter generally were not detected. High-resolution CT appeared more sensitive than standard CT (75% vs. 58%). Adrenal venous sampling for aldosterone assay was the most sensitive of the three methods, localizing 22 (96%) of the 23 adenomas. Eighteen (78%) of the adenomas were identified by adrenal venography, although two patients with bilateral cortical hyperplasia were mistakenly diagnosed as having a small adenoma. No such false-positive studies were encountered with CT or adrenal venous sampling.