Best Scan for Adrenal Gland Tumor and Conn's Syndrome. Without a doubt the best x-ray or scan for patients with primary hyperaldosteronism is a "contrast enhanced CT scan”. An unenhanced (no contrast) CT, adenomas are usually well-demarcated round or oval lesions, with homogeneous and relatively low attenuation values. In almost all cases, this scan is all you need. Only occasionally is an MRI helpful in these patients. Dr. Carling published one of the landmark research studies when it comes to imaging of aldosterone-producing adenoma (APA). We often refer to this type of CAT scan with contrast for the adrenal gland the “adrenal-protocol CAT scan".

What we can tell from the adrenal CT Scan There is much to be learned from a propperly conducted CAT scan of the adrenal gland, so it is in your best interest to have this performed by doctors who do lots of these. Experience really matters. The scan will tell which adrenal gland has the tumor in it (the right or the left) and where in the adrenal gland it is located. It will also show the size of the aldosterone-producing tumor and where it is in relationhsip to the kidney, stomach, spleen, liver, pancreas, intestines, and the major blood vessels such as the vena cava and renal veins.

Dr. Carling’s very high volume of these operations has allowed him to publish scientific studies demonstrated that in aldosterone-producing adenomas (APA), there is a strong correlation between the imaging phenotype (i.e. what your tumor looks like on a CT scan), histology (what your tumor looks like under the microscope) and genotype (what gene is mutated in the tumor).


Dr. Carling, Editorial note: If you have primary hyperaldosteronism, do not worry what your endocrinologist or radiologist (X-ray) doctor thinks about your scan, your tumor size, or tumor location--let us decide--we do more of this than anybody. Also, do not waste time obtaining unnecessary expensive scans (for instance an MRI), or an invasive adrenal vein sampling procedure. In rare cases you may need it, but most often you don’t and inexperienced doctors and surgeons will get MANY scans and x-rays that you do not need. Dr. Carling has seen it all and almost all patients have scans they did not need and these scans confuse the doctors and give the patients and the doctors too much fear and apprehension. Dr Carling has created the scientific basis of the disease via the major international studies and can in minutes figure out what is going on with your adrenal tumor and aldosterone-producing adrenal adenomas (APA).

Simply contact us. Send us your data and your scan. We know what to do. We can save you significant time and money avoiding wasteful and unnecessary test and get you on your way to a cure!
Adrenal Vein Sampling (AVS) for adrenal tumors Adrenal vein sampling is sometimes needed to distinguish unilateral from bilateral adrenal sources of aldosterone secretion. This is an interventional radiology study. AVS should be performed in all patients with a CT scan that is equivocal or demonstrates adrenal tumors on both the right and the left side. Through small catheters blood samples are obtained from each adrenal vein and the inferior vena cava sequentially, or simultaneously. In experienced centers, the bilateral adrenal veins are catheterized and sampled with a technical success rate exceeding 90%. Technical success is directly associated with operator experience, leading to the recommendation that the procedure be performed by one or two operators at a institution to maximize expertise.

Dr. Carling, Editorial note: Unless your endocrinologist has extensive experience in identifying the best interventional radiologist to perform the Adrenal Vein Sampling procedure (if you need it), call us! We know who can do this procedure with great success rates and safely. But remember, MOST patients with Conn's Syndrome and hyperaldosteronism do not need Adrenal Vein Sampling.

Warning: Technical Information about Adrenal Vein Sampling: Because the normal adrenal gland produces cortisol in response to ACTH, venous cortisol levels are used as a positive control to determine that the AV is adequately sampled. The cortisol level in each adrenal vein is compared to peripheral samples taken from the inferior vena cava. Once it has been proven that both left and right adrenal veins have been adequately sampled, the next step is to determine if results are lateralizing to one gland (see if the hormone is higher on one side than the other). The aldosterone level (A) in each sample is normalized to the cortisol level. Then, one side is divided by the other to determine the lateralization index (LI) A lateralization index greater than 4 is compatible with a unilateral source of aldosterone. Most centers use the LI to diagnose unilateral etiologies of PA; contralateral gland suppression can also confirm the presence of an aldosterone-producing adenomas (APA).

Dr. Carling, Editorial note: Again, if you have primary hyperaldosteronism, let us review your imaging (send us your CT scan). Dr. Carling has more experience looking at adrenal tumors on CT scans (and has published widely about it) than almost any endocrinologist or radiologist (X-ray) doctor in the world. Also, do not waste time obtaining unnecessary expensive scans (for instance an MRI that almost nobody with this type of adrenal problem needs), or an invasive adrenal vein sampling procedure. Rarely you may need it, but most often you don’t). Dr. Carling has seen it all. He has created the scientific basis of the disease via the major international studies and can in minutes figure out provided what is going on with your aldosterone-producing adenomas (APA).


Technical information for doctors regarding adrenal-gland CT Scans> The high fat content in lesions with a fasciculata-like appearance explains lower Hounsfield units on CT scans and the presence of this histological feature in almost all KCNJ5-positive tumors studied explains the association with lower pre-contrast Hounsfield units on CT scans. The high prevalence of fasciculata-like APAs with KCNJ5 mutations explains the overall predominance of this histopathological phenotype. The histological features of zona fasciculata do not appear to be associated with cortisol secretion in the vast majority of cases, although rare cases of adenomas secreting both cortisol and aldosterone with KCNJ5 mutations have been described. KCNJ5-positive tumors also appear to be larger than others. This may have a direct clinical implication. It has previously been suggested that adrenal venous sampling may not be necessary in patients younger than age 40 with solitary unilateral apparent adenoma2, however the cut-off for age is debated. In line with this suggestion, we propose that young, especially female, patients with larger tumors displaying lower H.U. on CT scan, suggesting the presence of a KCNJ5 mutant tumor, may be able to avoid preoperative adrenal vein sampling.


If you have an adrenal gland tumor, do not fret. This is all we do and we can make this very easy for you. Simply contact us. Send us your data and your scan. We know what to do. We can save you significant time and money avoiding wasteful and unnecessary test and get you on your way to a cure!