Systematic Review: Diagnostic Procedures to Differentiate Unilateral From Bilateral Adrenal Abnormality in Primary Aldosteronism

Kempers ME, Lenders JM, van Outheusden L, et al. — Tue, 01 Sep 2009 00:00:00 GMT

Background:

Computed tomography (CT), magnetic resonance imaging (MRI), and adrenal vein sampling (AVS) are used to distinguish unilateral from bilateral increased aldosterone secretion as a cause of primary aldosteronism. This distinction is crucial because unilateral primary aldosteronism can be treated surgically, whereas bilateral primary aldosteronism should be treated medically.

Purpose:

To determine the proportion of patients with primary aldosteronism whose CT or MRI results with regard to unilateral or bilateral adrenal abnormality agreed or did not agree with those of AVS.

Data Sources:

PubMed, MEDLINE, EMBASE, and Cochrane Library, 1977 to April 2009.

Study Selection:

Studies describing adults with primary aldosteronism who underwent CT/MRI and AVS were included. Of 472 initially identified studies, 38 met the selection criteria; extractable data were available for 950 patients.

Data Extraction:

The CT/MRI result was considered accurate when AVS showed unilaterally increased aldosterone secretion on the same side as the abnormality seen on CT/MRI or when AVS showed symmetric aldosterone secretion and CT/MRI revealed bilateral or no unilateral abnormality.

Data Synthesis:

In 37.8% of patients (359 of 950), CT/MRI results did not agree with AVS results. If only CT/MRI results had been used to determine lateralization of an adrenal abnormality, inappropriate adrenalectomy would have occurred in 14.6% of patients (where AVS showed a bilateral problem), inappropriate exclusion from adrenalectomy would have occurred in 19.1% (where AVS showed unilateral secretion), and adrenalectomy on the wrong side would have occurred in 3.9% (where AVS showed aldosterone secretion on the opposite side).

Limitation:

The lack of follow-up data in the included articles made it impossible to confirm that adrenalectomies were performed appropriately.

Conclusion:

When AVS is used as the criterion standard test for diagnosing laterality of aldosterone secretion in patients with primary aldosteronism, CT/MRI misdiagnosed the cause of primary aldosteronism in 37.8% of patients. Relying only on CT/MRI may lead to inappropriate treatment of patients with primary aldosteronism.

Primary Aldosteronism—One Picture Is Not Worth a Thousand Words

Young WF, Jr.. — Tue, 01 Sep 2009 00:00:00 GMT

Physicians often rely on imaging to guide clinical decision making. When computed tomography (CT) or magnetic resonance imaging (MRI) is used to demonstrate adrenal morphologic appearance in patients with primary aldosteronism, the images may lead to errors in clinical management. In this issue, Kempers and colleagues (1) report a systematic review of the diagnostic procedures to distinguish between unilateral and bilateral adrenal disease in patients with primary aldosteronism. Their key finding, based on 950 patients with primary aldosteronism from 38 studies, is that the adrenal morphologic appearance on CT or MRI does not accurately identify the source of aldosterone excess (1).

Annals of Internal Medicine: Endocrine Cancer Topic Collection

Systematic Review: Diagnostic Procedures to Differentiate Unilateral From Bilateral Adrenal Abnormality in Primary Aldosteronism

Primary Aldosteronism—One Picture Is Not Worth a Thousand Words