How to avoid pitfalls in interpretation of adrenal imaging

By Philip Ward, AuntMinnieEurope.com staff writer

January 15, 2019 — A clear understanding of the pitfalls in the performance and interpretation of adrenal CT can help prevent incorrect and inappropriate investigations, award-winning researchers from a top London facility have found. It’s essential to keep aware of the full range of pseudolesions and mimics, they said.

“Evaluation of adrenal tumor function is limited on imaging, but may be inferred from imaging findings,” noted Dr. Gurinder Nandra and colleagues from the department of radiology at St. George’s University Hospitals NHS Foundation Trust in an e-poster presentation that received a cum laude award at RSNA 2018 in Chicago.

Other adrenal pathology, including metastases and adrenocortical carcinoma, may be encountered, and this means it’s important to know about the imaging approaches to evaluate the adrenals, the authors pointed out.

Incidental adrenal nodules are identified in around 5% of patients who undergo CT. The prevalence of detecting incidentalomas increases with age, but most incidentally encountered adrenal pathology is benign and of little clinical relevance, they wrote. Adenomas are by far the most common adrenal pathology identified.

Among the technical aspects that deserve special attention are the following:

  • The region of interest (ROI): Changing the size of the ROI can alter the perceived attenuation of the nodule. The ROI should cover at least two-thirds of the circumference of the nodule, and exclude tiny areas of heterogeneity from the ROI (e.g., flecks of calcification) that are not representative of the adrenal pathology. Unenhanced attenuation of less than 10 Hounsfield units (HU) can be used to diagnose lipid-rich adrenal adenoma (sensitivity 71%, specificity of 98%).
  • Attenuation values on unenhanced CT: A homogenously dense lesion on unenhanced CT suggests a lack of microscopic lipid content. If attenuation on unenhanced CT is greater than 20 to 30 HU, evaluate the enhancement kinetics with CT.
  • Effect of kVp on attenuation values in a dual energy study: To use threshold of less than 10 HU to diagnose a lipid-rich adrenal adenoma, the kVp should be 120. Changing kVp can alter the attenuation values of soft tissues and adrenal glands.
  • Timing of post-contrast acquisitions: “Imaging needs to be performed at the correct times to allow sufficient time for enhancement and washout of contrast. Post-contrast images should be obtained at 60 to 75 seconds and 15 minutes,” the authors stated.
  • Assessment of washout on nondedicated studies: Relative washout can be calculated on nondedicated studies if more than one acquisition is made within 15 minutes post-intravenous contrast.
  • Suspicious attenuation: Attenuation of more than 43 HU on noncontrast CT is suspicious for malignancy, regardless of washout characteristics. PET/CT is of more use than CT and MRI in such cases, and adrenal hemorrhage also is a consideration at this attenuation.
  • Evaluation of small nodules: Minor nodularity of less than 1 cm in diameter does not require further radiological investigation. Also, CT evaluation of small adrenal nodules is limited by partial volume artifacts. MRI evaluation of small adrenal nodules is limited by the India ink artifact, or black boundary artifact, on an out-of-phase sequence. This artifact may give the impression of signal loss and lead to an incorrect diagnosis of a lipid-rich adenoma.
  • Evaluation of large adrenal masses: Malignancy risk increases with size (over 4 cm, 70%; over 6 cm, 85%) when excluding myelolipoma. In the absence of known malignancy, an adrenal lesion of less than 4 cm with indeterminate imaging features is likely to be benign.
  • Enhancement characteristics of metastases: Enhancement/washout characteristics of adrenal metastases are variable, and they can be confused with pheochromocytoma.
  • Adrenal calcification: Calcification is seen in benign adrenal pathology, but also can be seen in cases of malignancy, including adrenocortical carcinoma. “Look for ancillary features of malignancy including size, heterogeneity and invasion,” the authors recommended. “Evaluation of a predominantly calcified adrenal lesion will be limited with chemical shift MRI.”
  • Heterogeneous signal loss: Heterogeneous signal loss is not typical for a small lipid-rich adenoma and raises the possibility of malignant pathology. It also can be seen in larger adenomas because of calcification/cystic change/myelolipomatous metaplasia.

In their RSNA 2018 exhibit, Nandra and colleagues also identified the following list of mimics that can crop up:

  • Mimics arising from gastrointestinal tract: Gastric pathology can extend into the left suprarenal space and mimic adrenal pathology. The most common mimics include gastrointestinal stromal tumors and gastric diverticula. Pathology elsewhere in the gastrointestinal tract can mimic adrenal pathology (e.g., a fluid-filled colon).
  • Mimics arising from solid viscera: Pathology from the spleen, pancreas, liver, and kidneys can extend into the suprarenal space and mimic adrenal pathology. This includes splenic lobulation, splenunculi, upper pole renal pathology, pancreatic tail pathology, and exophytic hepatic lesions.
  • Mimics arising from vessels: Dilated, tortuous, or aneurysmal vessels may extend into the suprarenal space and mimic adrenal pathology. The most common mimics include splenic varices and splenic artery pseudoaneurysms.
  • Mimics arising from retroperitoneal tissues: Various retroperitoneal lesions can extend into the suprarenal space and mimic adrenal pathology, and normal anatomy in the retroperitoneum also can mimic adrenal pathology (e.g., a thickened diaphragmatic crus).

From https://www.auntminnieeurope.com/index.aspx?sec=ser&sub=def&pag=dis&ItemID=616803

Cushing’s Syndrome Etiology Affects Adrenal Function Recovery

The aim was to analyze the postsurgical duration of adrenal insufficiency of patients with Cushing’s disease (CD), adrenal CS and ectopic CS.

Design:

We performed a retrospective analysis based on the case records of 230 CS patients in our tertiary referral center treated from 1983 to 2014. The mean follow-up time was 8 years.

The probability of recovering adrenal function within a 5 years follow-up differed significantly between subtypes (p=0.001). It was 82 % in ectopic CS, 58 % in Cushing’s disease and 38 % in adrenal CS. In the total cohort with restored adrenal function (n=52) the median time to recovery differed between subtypes: 0.6 (IQR 0.03–1.1) years in ectopic CS, 1.4 (IQR 0.9–3.4) years in CD, and 2.5 (IQR 1.6–5.4) years in adrenal CS (p=0.002). In CD the Cox proportional-hazards model showed that the probability of recovery was associated with younger age (hazard ratio 0.896, 95% CI 0.822–0.976, p=0.012), independently of sex, BMI, duration of symptoms, and basal ACTH and cortisol levels. There was no correlation with length and extend of hypercortisolism or postoperative glucocorticoid replacement doses.

Conclusions:

Time to recovery of adrenal function is dependent on the underlying etiology of CS.

Myth: “Each Person Requires the Same Dose of Steroid in Order to Survive…

Myth: “Each person requires the same dose of steroid in order to survive with Secondary or Primary Adrenal Insufficiency”

myth-busted

Fact: In simple terms, Adrenal Insufficiency occurs when the body does not have enough cortisol in it. You see, cortisol is life sustaining and we actually do need cortisol to survive. You have probably seen the commercials about “getting rid of extra belly fat” by lowering your cortisol. These advertisements make it hard for people to actually understand the importance of the function of cortisol.

After a Cushing’s patient has surgery, he/she goes from having very high levels of cortisol to no cortisol at all. For pituitary patients, the pituitary, in theory, should start working eventually again and cause the adrenal glands to produce enough cortisol. However, in many cases; the pituitary gland does not resume normal functioning and leaves a person adrenally insufficient. The first year after pit surgery is spent trying to get that hormone to regulate on its own normally again. For a patient who has had a Bilateral Adrenalectomy (BLA), where both adrenal glands are removed as a last resort to “cure” Cushing’s; his/her body will not produce cortisol at all for his/her life. This causes Primary Adrenal Insufficiency.

All Cushing’s patients spend time after surgery adjusting medications and weaning slowly from steroid (cortisol) to get the body to a maintenance dose, which is the dose that a “normal” body produces. This process can be a very long one. Once on maintenance, a patient’s job is not over. He/She has to learn what situations require even more cortisol. You see, cortisol is the stress hormone and also known as the Fight or Flight hormone. Its function is to help a person respond effectively to stress and cortisol helps the body compensate for both physical and emotional stress. So, when faced with a stressor, the body will produce 10X the baseline levels in order to compensate. When a person can not produce adequate amounts of cortisol to compensate, we call that Adrenal Insufficiency. If it gets to the point of an “Adrenal Crisis”, this means that the body can no longer deal and will go into shock unless introduced to extremely high levels of cortisol, usually administered through an emergency shot of steroid.

There are ways to help prevent a crisis, by taking more steroid than the maintenance dose during times of stress. This can be anything from going to a family function (good stress counts too) to fighting an infection or illness. Acute stressors such as getting into a car accident or sometimes even having a really bad fight require more cortisol as well.

It was once believed that everyone responded to every stressor in the exact same way. So, there are general guidelines about how much more cortisol to introduce to the body during certain stressors. For instance, during infection, a patient should take 2-3X the maintenance dose of steroid (cortisol). Also, even the maintenance dose was considered the same for everyone. Now a days, most doctors will say that 20 mg of Hydrocortisone (Steroid/Cortisol) is the appropriate maintenance dose for EVERYONE. Now, we know that neither is necessarily true. Although the required maintenance dose is about the same for everyone; some patients require less and some require more. I have friends who will go into an adrenal crisis if they take LESS than 30 mg of daily steroid. On the other hand, 30 mg may be way too much for some and those folks may even require LESS daily steroid, like 15 mg. Also, I want to stress (no pun intended) that different stressors affect different people differently. For some, for instance, an acute scare may not affect them. However, for others, receiving bad news or being in shock WILL put their bodies into crisis. That person must then figure out how much additional steroid is needed.

Each situation is different and each time may be different. Depending on the stressor, a person may need just a little more cortisol or a lot. Every person must, therefore, learn their own bodies when dealing with Adrenal Insufficiency. This is VERY important! I learned this the hard way. As a Clinical Psychologist; I assumed that my “coping skills” would be enough to prevent a stressor from putting me into crisis. That was FAR from the truth! I have learned that I can not necessarily prevent my body’s physiological response to stress. People often ask me, “BUT you are a psychologist! Shouldn’t you be able to deal with stress?!!!!” What they don’t realize is that my BODY is the one that has to do the job of compensating. Since my body can not produce cortisol at all, my job is to pay close attention to it so that I can take enough steroid to respond to any given situation. We all have to do that. We all have to learn our own bodies. This is vitally important and will save our lives!

To those we have lost in our community to Adrenal Insufficiency after treatment of Cushing’s, Rest in Peace my friends! Your legacies live on forever!

~ By Karen Ternier Thames

CV risk elevated in patients with adrenal incidentalomas, mild hypercortisolism

Patients with adrenal incidentalomas and mild hypercortisolism have an increased risk for cardiovascular events and mortality. This risk was evident even when clinical signs of overt hypercortisolism were not present, according to data published in The Lancet Diabetes & Endocrinology.

“Our findings are important because they add to the previously scant information about adrenal incidentalomas, which will be of use to doctors who are seeing an increasing number of patients with these masses,” Renato Pasquali, MD, of the S. Orsola-Malpighi Hospital in Bologna, Italy, said in a press release.

The retrospective study by Pasquali and colleagues assessed the adrenal incidentalomas of 198 outpatients treated every 18 to 30 months, with a mean follow-up of 7.5 years. At the time of follow-up, 114 patients demonstrated stable non-secreting adrenal incidentalomas (<50 nmol/L), 61 had either a stable intermediate phenotype (50 nmol/L-138 nmol/L) or subclinical Cushing’s syndrome (>138 nmol/L), and 23 patients had worsening pattern of secretion.

The incidence of CV events appeared higher in patients with a stable intermediate phenotype or subclinical Cushing’s syndrome (6.7% vs. 16.7%; P=.04) and in those with worsened secreting patterns (6.7% vs. 28.4%; P=.02) compared with patients with stable non-secreting adrenal incidentalomas, according to data.

In addition, CV events were independently related to changes in cortisol concentrations after the 1-mg dexamethasone suppression test (DST; HR=1.13; 95% CI, 1.05-1.21) from baseline to follow-up.

Patients with stable intermediate phenotype adrenal incidentalomas (57%) or subclinical Cushing’s syndrome (91.2%) tended to have lower survival rates for all-cause mortality (P=.005), researchers wrote. The main risk factors for all-cause mortality were age (HR=1.06; 95% CI, 1.01-1.12) and mean concentrations of cortisol after DST (HR=1.1; 95% CI, 1.01-1.19).

The unadjusted survival for CV-related mortality was lower in patients with either a stable intermediate phenotype (97.5%) or subclinical Cushing’s syndrome (78.4%; P=.02) vs. those with stable non-secreting adrenal incidentalomas (97.5%), and patients with worsened secreting patterns (60%; P=.01).

In an accompanying comment, Rosario Pivonello, MD, PhD, Maria Cristina De Martino, PhD, and Annamaria Colao, MD, PhD, of the Federico II University of Naples, Italy, wrote that the study supports the importance of long-term hormonal follow-up for clinical management of patients with adrenal incidentalomas.

“Furthermore, clinical monitoring of cardiometabolic risks seems to be important in these patients, particularly in those with subclinical Cushing’s syndrome and intermediate phenotype adrenal incidentalomas, for whom medical or surgical intervention could be needed,” they wrote.

They suggest long-term prospective studies to determine the frequency of new CV events and mortality in this patient population.

For more information:

Di Dalmazi G. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(13)70211-0.

Pivonello R. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(13)70190-6.

Disclosure: The researchers report no relevant financial disclosures.

This article is from http://www.healio.com/endocrinology/adrenal/news/online/%7B85f94352-9529-4cb7-9532-9c4518f77d80%7D/cv-risk-elevated-in-patients-with-adrenal-incidentalomas-mild-hypercortisolism

 

Adrenal Diseases During Pregnancy: Pathophysiology, Diagnosis And Management Strategies

Am J Med Sci. 2014 Jan;347(1):64-73. doi: 10.1097/MAJ.0b013e31828aaeee.

Author information

Abstract

: Adrenal diseases-including disorders such as Cushing’s syndrome, Addison’s disease, pheochromocytoma, primary hyperaldosteronism and congenital adrenal hyperplasia-are relatively rare in pregnancy, but a timely diagnosis and proper treatment are critical because these disorders can cause maternal and fetal morbidity and mortality.

Making the diagnosis of adrenal disorders in pregnancy is challenging as symptoms associated with pregnancy are also seen in adrenal diseases. In addition, pregnancy is marked by several endocrine changes, including activation of the renin-angiotensin-aldosterone system and the hypothalamic-pituitary-adrenal axis.

The aim of this article was to review the pathophysiology, clinical manifestation, diagnosis and management of various adrenal disorders during pregnancy.

PMID:
23514671
[PubMed – in process]

From http://www.ncbi.nlm.nih.gov/pubmed/23514671