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PubMed This is a summary of 16 peer-reviewed journal articles Updated
Endocrinology · Primary Aldosteronism

Mapping the Problem: Finding the Source

At a Glance

To treat primary aldosteronism effectively, doctors must determine if the excess hormone comes from one or both adrenal glands. Adrenal Venous Sampling (AVS) is the most accurate test for finding the source, as standard CT scans can miss tiny tumors or flag harmless lumps.

Once you have been diagnosed with Primary Aldosteronism (PA), the next critical step is called lateralization. This simply means figuring out if the excess hormone is coming from one adrenal gland (unilateral) or both (bilateral) [1]. This answer changes everything: one-sided disease can often be cured with surgery, while two-sided disease is managed with medication [2][3].

The Limits of Standard Scans

Many patients assume a standard CT or MRI will provide the answer. While your doctor will order a CT scan first, its main job is to rule out rare adrenal cancers or very large growths [4]. For lateralization, CT scans have two major flaws:

  1. Incidentalomas: As we age, it is very common to have small, harmless “lumps” on the adrenal glands that don’t produce any hormones at all. A CT scan might see a lump on the left, while the right gland is actually the one overproducing aldosterone [4][5].
  2. Microscopic Tumors: Many aldosterone-producing tumors are so tiny they are invisible to a standard CT scan [6].

The Gold Standard: Adrenal Venous Sampling (AVS)

Because imaging can be misleading, doctors use Adrenal Venous Sampling (AVS) to get the real story [3]. During this procedure, an interventional radiologist inserts a thin tube (catheter) into the veins that drain your adrenal glands [1].

  • How it works: The radiologist takes blood samples directly from each adrenal vein and a “control” sample from elsewhere in the body. By comparing the amount of aldosterone on the left side versus the right side, they can determine exactly where the problem lies [1][7].
  • The Skill Factor: AVS is a technically difficult procedure. The right adrenal vein is particularly tiny and hard to find. It is essential that this procedure is performed by an experienced radiologist who does it frequently to ensure the samples are accurate [8][9].

New Frontiers: Molecular Imaging

For patients who cannot undergo AVS or want a non-invasive option, new types of “functional” scans are emerging. The most promising is the 68Ga-Pentixafor PET/CT [10].

Unlike a standard CT, which just looks at the shape of the gland, this scan uses a “tracer” that sticks specifically to the receptors found in aldosterone-producing tumors [11]. It acts like a “heat map,” showing exactly which parts of the glands are overactive [12]. Studies have shown that this scan can be just as accurate as AVS in many patients [13][14].

Why This Step Matters

The stakes for lateralization are high. If you have a one-sided tumor and have surgery (adrenalectomy), your aldosterone and potassium levels will normalize in about 95% of cases, and more than half of patients are able to stop taking blood pressure medication entirely [15]. If the disease is two-sided, surgery is usually not the best option, and you will instead be treated with targeted medications that block the excess aldosterone and protect your heart [2][3]. Obtaining an accurate “map” of your condition is the only way to ensure you receive the correct treatment [16].

Common questions in this guide

Why do I need Adrenal Venous Sampling (AVS) instead of just a CT scan?
Standard CT scans only show the physical shape of your adrenal glands, meaning they can miss tiny tumors or mistakenly flag harmless lumps that do not produce hormones. AVS measures hormone levels directly from the veins, accurately identifying exactly which gland is overproducing aldosterone.
What happens if my CT scan and AVS results do not match?
Doctors generally trust the results of the AVS procedure over a standard CT scan. Because AVS tests the actual hormone production rather than just the physical appearance of the glands, it provides the most accurate map of the problem.
Is there a non-invasive alternative to the AVS procedure?
A new type of molecular imaging called a 68Ga-Pentixafor PET/CT scan is emerging as a promising option. It uses a specialized tracer that acts like a heat map to reveal overactive areas in the adrenal glands without requiring an invasive procedure.
Will surgery cure my primary aldosteronism if the tumor is on one side?
If testing confirms the condition is unilateral (one-sided), surgery normalizes aldosterone and potassium levels in about 95% of cases. Additionally, more than half of patients are able to stop taking blood pressure medications entirely after the procedure.
Why is the experience of the radiologist so important for AVS?
Adrenal venous sampling is a technically difficult procedure because the right adrenal vein is very small and hard to locate. Having a highly experienced interventional radiologist perform the procedure is crucial for getting accurate blood samples and minimizing risks.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How many adrenal venous sampling (AVS) procedures does your interventional radiologist perform each year?
  2. 2.If my CT scan shows a nodule on one side but my AVS shows hormone production on both sides, which result will we trust?
  3. 3.Is the 68Ga-Pentixafor PET/CT scan available at this facility as an alternative or a supplement to AVS?
  4. 4.What are the specific risks of AVS at this hospital, such as the risk of adrenal hemorrhage?
  5. 5.If my AVS results are successful, what are the odds that surgery will allow me to stop taking blood pressure medications entirely?

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References

References (16)
  1. 1

    Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance.

    Loberg C, Antoch G, Stegbauer J, et al.

    RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin 2021; (193(6)):658-666 doi:10.1055/a-1299-1878.

    PMID: 33327032
  2. 2

    Mineralocorticoid Receptor Antagonists in Primary Aldosteronism.

    Stavropoulos K, Papadopoulos C, Koutsampasopoulos K, et al.

    Current pharmaceutical design 2018; (24(46)):5508-5516 doi:10.2174/1381612825666190311130138.

    PMID: 30854950
  3. 3

    A novel clinical nomogram to predict bilateral hyperaldosteronism in Chinese patients with primary aldosteronism.

    Xiao L, Jiang Y, Zhang C, et al.

    Clinical endocrinology 2019; (90(6)):781-788 doi:10.1111/cen.13962.

    PMID: 30820995
  4. 4

    The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline.

    Funder JW, Carey RM, Mantero F, et al.

    The Journal of clinical endocrinology and metabolism 2016; (101(5)):1889-916 doi:10.1210/jc.2015-4061.

    PMID: 26934393
  5. 5

    Development and validation of model for sparing adrenal venous sampling in diagnosing unilateral primary aldosteronism.

    Song Y, Yang J, Shen H, et al.

    Journal of hypertension 2022; (40(9)):1692-1701 doi:10.1097/HJH.0000000000003197.

    PMID: 35881462
  6. 6

    Saline suppression test parameters may predict bilateral subtypes of primary aldosteronism.

    Hashimura H, Shen J, Fuller PJ, et al.

    Clinical endocrinology 2018; (89(3)):308-313 doi:10.1111/cen.13757.

    PMID: 29873811
  7. 7

    Adrenal venous sampling for primary aldosteronism: laboratory medicine best practice.

    Kline G, Holmes DT

    Journal of clinical pathology 2017; (70(11)):911-916 doi:10.1136/jclinpath-2017-204423.

    PMID: 28893861
  8. 8

    Initial experience with adrenal vein sampling using 3D cursor and preprocedural computed tomography (CT) scout image.

    Kim MS, Hong HP, Park CY, et al.

    Clinical radiology 2025; (86()):106928 doi:10.1016/j.crad.2025.106928.

    PMID: 40413853
  9. 9

    Success rate of adrenal venous sampling and predictors for success: a retrospective study.

    Chayovan T, Limumpornpetch P, Hongsakul K

    Polish journal of radiology 2019; (84()):e136-e141 doi:10.5114/pjr.2019.84178.

    PMID: 31019607
  10. 10

    Clinical diagnosis and treatment of a patient with hypertension, hypokalemia, and bilateral adrenal adenomas.

    Zhang T, Chen T, Zhang W, et al.

    Frontiers in endocrinology 2025; (16()):1558841 doi:10.3389/fendo.2025.1558841.

    PMID: 40416524
  11. 11

    The Value of Targeting CXCR4 With 68Ga-Pentixafor PET/CT for Subtyping Primary Aldosteronism.

    Zheng Y, Long T, Peng N, et al.

    The Journal of clinical endocrinology and metabolism 2023; (109(1)):171-182 doi:10.1210/clinem/dgad421.

    PMID: 37477496
  12. 12

    68Ga-Pentixafor PET/CT for diagnosing surgically curable primary aldosteronism concurrent with autonomous cortisol secretion.

    Jiang Y, Zhang X, Zeng Q, et al.

    Journal of hypertension 2026; (44(7)):1221-1229 doi:10.1097/HJH.0000000000004319.

    PMID: 42201658
  13. 13

    Pooled diagnostic accuracy of 68Ga-pentixafor PET/CT for aldosterone-producing lesions in primary aldosteronism.

    Ohannesian VA, Rajchenberg D, Menezes IR, et al.

    Clinical imaging 2026; (131()):110743 doi:10.1016/j.clinimag.2026.110743.

    PMID: 41653499
  14. 14

    Identification of Aldosterone-Producing Adrenal Adenomas Using [68Ga]Ga-Pentixafor PET/CT in an Australian Cohort.

    Ng E, Jong I, Lau KK, et al.

    Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2026; (67(4)):606-614 doi:10.2967/jnumed.125.271006.

    PMID: 41611475
  15. 15

    Biochemical and clinical remission after adrenalectomy in patients with primary aldosteronism: a retrospective two-center study.

    Matthey Giè ML, St-Amour P, Karenovics W, et al.

    Gland surgery 2026; (15(5)):137 doi:10.21037/gs-2026-1-0087.

    PMID: 42299293
  16. 16

    Use of plasma metanephrine to aid adrenal venous sampling in combined aldosterone and cortisol over-secretion.

    Goupil R, Wolley M, Ungerer J, et al.

    Endocrinology, diabetes & metabolism case reports 2015; (2015()):150075 doi:10.1530/EDM-15-0075.

    PMID: 26557366

This page is for educational purposes only and does not replace professional medical advice. Always discuss diagnostic procedures like AVS and your imaging results with your endocrinologist or care team to determine the best treatment plan.

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