Feasibility Study of Single-Photon Emission Computed Tomography with Iodine-123 Labeled Metaiodobenzylguanidine for Preclinical Evaluation of Labetalol as a ß-Adrenergic Receptor Blocker.

Among clinically used radiopharmaceuticals, iodine-123 labeled metaiodobenzylguanidine ([123I]mIBG) serves for diagnosing neuroendocrine tumors and obtaining images of myocardial sympathetic innervation. mIBG, a structural analogue of norepinephrine (NE), a neurotransmitter acting in peripheral and central nerves, follows a pathway similar to NE, transmitting signals through the NE transporter (NET) located at synaptic terminals. It moves through the body without decomposing, enabling noninvasive image evaluation. In this study, we aimed to quantify [123I]mIBG uptake in the adrenal glands using small animal single-photon emission computed tomography/computed tomography (SPECT/CT) images post [123I]mIBG administration. We investigated the possibility of assessing the effectiveness of ß-adrenergic receptor blockers by quantifying SPECT/CT images and biodistribution results to determine the degree of [123I]mIBG uptake in the adrenal glands treated with labetalol, a known ß-adrenergic receptor blocker. Upon intravenous administration of [123I]mIBG to mice, SPECT/CT images were acquired over time to confirm the in vivo distribution pattern, revealing a clear uptake in the adrenal glands. Labetalol inhibited the uptake of [123I]mIBG in cell lines expressing NET. A decrease in [123I]mIBG uptake in the adrenal glands was observed in the labetalol-treated group compared with the normal group through SPECT/CT imaging and biodistribution studies. These results demonstrate that SPECT/CT imaging with [123I]mIBG could be applicable for evaluating the preclinical efficacy of new antihypertensive drug candidates such as labetalol, a ß-adrenergic receptor blocker.

Adrenal Vein Sampling: Tips and Tricks.

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Portal venous contrast enhancement ratio of the adrenal glands and spleen as prognostic marker of mortality in patients with acute mesenteric ischemia.

PURPOSE: Contrast enhancement of the adrenal gland defined by computed tomography (CT) was previously analyzed as a prognostic factor for critically ill patients in various diseases. However, no study investigated this quantitative parameter in patients with acute mesenteric ischemia. Therefore, the aim of this study was to evaluate the prognostic value of the contrast enhancement of the adrenal glands in patients with clinically suspected AMI. METHODS: All patients with clinically suspected AMI were retrospectively assessed between 2016 and 2020. All patients underwent surgical exploration after CT imaging. Overall, 134 patients (52 female patients, 38.8%) with a mean age of 69.2 ± 12.4 years were included into the present analysis. For all patients, the preoperative CT was used to calculate the contrast media enhancement of the adrenal glands and the spleen. RESULTS: A total of 27 patients (18.5%) died within the first 24 h and over the following 30-day 94 patients (68.6%) died. There were statistically significant differences regarding the mean values for adrenal-to-spleen ratio for 24-h mortality (p = 0.001) and 30-day mortality (p = 0.004), whereas the radiodensity of the inferior vena cava and the radiodensity of the spleen was statistically significant between survivors and non-survivors after 30 days (p = 0.037 and p = 0.028, respectively). In Cox regression analysis, mean adrenal radiodensity was associated with 24-h mortality (HR 1.09, 95% CI 1.02-1.16, p = 0.01) but not with 30-day mortality (HR 1.03, 95% CI 0.99-1.07, p = 0.13). CONCLUSION: The contrast media enhancement of the adrenal gland is associated with the 24-h and 30-day mortality in patients with AMI. However, the prognostic relevance for translation into clinical routine needs to be validated in other cohorts.

Adrenal morphology and cortical function in patients with extrapulmonary tuberculosis: response to antituberculosis treatment.

Objective: Enlargement of the adrenal glands and variable adrenocortical function have been reported in patients with pulmonary tuberculosis and, in a few studies, in patients with extrapulmonary tuberculosis (EPTB). However, none of the studies have evaluated the course of the adrenal morphology in these patients. Subjects and methods: Prospective study including 37 patients with EPTB and 37 healthy age- and sex-matched controls. The adrenal function was evaluated by measurement of cortisol levels at baseline and after stimulation with ACTH (Acton Prolongatum) before and 6 months after antituberculosis treatment. The size of both adrenal glands was evaluated using 64-slice computed tomography (CT) scanning before and 6 months after treatment. The findings were compared with those in a group of healthy matched controls. Results: Clinical and biochemical parameters were comparable between groups. The mean baseline serum cortisol level was significantly lower in the EPTB group (397.1 ± 184.9 nmol/L) compared with the control group (696.3 ± 101.8 nmol/L). Compared with controls, patients with EPTB had significantly lower mean cortisol levels at baseline and 1 hour after ACTH, both before (397 ± 184.9 nmol/L and 750.7 ± 176.8 nmol/L, respectively) and after (529.7 ± 100.4 nmol/L and 1017.2 ± 119.7 nmol/L, respectively) antituberculosis treatment. Both the length and thickness of the right and left adrenal glands were greater in patients with EPTB than in controls but became comparable to those in controls after treatment completion. Conclusion: Patients with EPTB have an enlarged adrenal size and low baseline and stimulated serum cortisol levels. After treatment completion, cortisol levels increased significantly, and the adrenal size normalized in these patients.

True mesothelial cyst of the adrenal gland: its clinical profile and management.

The incidence of adrenal cysts is 0.06% and only 9% of these are true mesothelial cysts. Here, we present a case of a true mesothelial cyst together with a review of the literature. A female in her 30s presented to the surgical outpatient department complaining of right flank pain. Her contrast-enhanced CT scan revealed a 7.5×6.5×4.5 cm right adrenal gland cyst. The patient underwent a laparoscopic right adrenalectomy. Immunohistopathology revealed the cyst to be mesothelial in nature. The majority of true mesothelial adrenal cysts are benign, unilateral and more common in women. Any adrenal cyst diagnosed as a functional lesion or one that may be malignant or with a diameter of 5 cm or greater requires surgical care whereas smaller lesions can be managed conservatively. Laparoscopic adrenalectomy for an adrenal cyst of diameter greater than 6 cm is a safe and feasible procedure in expert hands if there is no invasion of surrounding tissue.

Brain tissue heterotopic in the adrenal gland in a child: a scarce case report.

Heterotopic brain tissue is rare and has not been reported. Our center made the first report. 4 years and 2 months old Girl presented with a cystic mass in the right adrenal gland 2 weeks after right upper abdominal pain. The operation was successful, and the diagnosis was confirmed by postoperative pathology. 6 months after the procedure, the incision healed well without recurrence. This case report has a detailed diagnosis and treatment process and satisfactory examination results. It can provide a reference for diagnosing and treating clinical HBT and reduce the risk of misdiagnosis and mistreatment.

Imaging Concordance With Vein Sampling for Primary Aldosteronism: A Cohort Study and Literature Review.

INTRODUCTION: Adrenal venous sampling (AVS) is used to distinguish unilateral from bilateral aldosterone hypersecretion as a cause of primary aldosteronism (PA). Unilateral disease is treated with adrenalectomy and bilateral hypersecretion managed medically. METHODS: We performed a single institution retrospective cohort study of adult patients undergoing adrenalectomy for PA from July 2013 to June 2022. Concordance of imaging findings with AVS was evaluated. Statistical analysis was performed with Mann-Whitney U and chi-squared Fisher's exact. Literature review performed via triple method search strategy. RESULTS: Twenty-one patients underwent AVS and adrenalectomy for PA. Two patients did not have imaging findings and 19 were localized with an adenoma. For patients with image localization, AVS was concordant in nine, discordant in four, and nondiagnostic in six. For patients with discordant findings, age range was 35.8 to 72.4 y compared with concordant patient age range of 49.8 to 71.7 y. Overall discordance between imaging results and AVS was 40%. The aldosterone level was associated with concordance with a median of 52 ng/dL compared with 26 ng/dL if discordant (P = 0.002). There was a significant reduction in antihypertensive medications for the entire cohort from a median of three medications (interquartile range 2-4) to 1 medication (interquartile range 1-2), P < 0.001. CONCLUSIONS: In this cohort, 40% of patients with selective AVS had discordant imaging and AVS results. Aldosterone level was associated with concordance. Hypertension was significantly improved with a median decrease of two antihypertensives. Our results support performance of AVS on all candidates for adrenalectomy for PA.

Multiple radiologist review of adrenal CT still frequently misses lateralized surgical primary aldosteronism.

Patients with primary aldosteronism (PA) have increased morbidity and mortality compared to those with essential hypertension. Accurate detection of lateralized PA is important so that affected patients can receive potentially curative adrenalectomy. However, around 40% of patients with lateralized PA have "normal" adrenal glands on computed tomography (CT). Additional independent review of imaging has been shown to improve diagnostic accuracy in many areas of imaging. Therefore, the authors sought to establish if multi-reader re-assessment of previously reported normal CT scans would result in increased detection of surgically remediable disease. The authors found that re-assessment of CT imaging by one, two, or three additional radiologists (or a combination thereof) slightly increased the detection of lateralized disease, but these differences were not statistically significant (p > .05). Readers had low inter-observer agreement (kappa = 0.17). If detection of a discrete nodule on CT was made a prerequisite for adrenal vein sampling (AVS), a second read by another reviewer would still result in an excess of missed cases (84.2%, 36.8%, and 65.8%, respectively, for each of the three independent reviewers). Therefore, a "normal" CT does not preclude the possibility of lateralized PA. Adrenal vein sampling should still be strongly considered wherever available and whenever surgery is considered for treatment of PA, irrespective of CT findings.

Feasibility of spectral CT-derived extracellular volume fraction for differentiating aldosterone-producing from nonfunctioning adrenal nodules.

OBJECTIVE: To assess the feasibility of spectral CT-derived extracellular volume (ECV) for differentiating aldosterone-producing nodules (APN) from nonfunctioning adrenal nodules (NFN). METHODS: Sixty-nine patients with biochemically and histologically confirmed unilateral APN (34) and NFN (35) as well as 23 patients with bilateral APN (19) and NFN (27) confirmed biochemically and by adrenal vein sampling (AVS) were enrolled in this retrospective study from October 2020 to April 2022. All patients underwent contrast-enhanced spectral CT of the adrenal glands with a 10-min delayed phase. The haematocrit level was measured within 2 days of CT. An iodine density map was derived from the delayed CT. The ECV fractions of the APN and NFN were calculated and compared in the test cohort of 69 patients with unilateral adrenal nodules. The optimal cut-off value was determined to evaluate the diagnostic efficacy of the ECV fraction for differentiating APN from NFN in the validation cohort of 23 patients with bilateral adrenal nodules. RESULTS: The ECV fractions of the APN (11.17 ± 4.57%) were significantly lower (p < 0.001) than that of the NFN (24.79 ± 6.01%) in the test cohort. At cut-off ECV value of 17.16%, the optimal area under the receiver operating characteristic curve was 0.974 (95% confidence interval: 0.942-1) with 91.4% sensitivity, 93.9% specificity, and 92.8% accuracy in the test cohort and 89.5% sensitivity, 96.3% specificity, and 93.5% accuracy in the validation cohort for differentiating APN from NFN. CONCLUSION: The spectral CT-derived ECV fraction can differentiate APN from NFN with high diagnostic performance. CLINICAL RELEVANCE STATEMENT: Spectral CT-derived extracellular volume fraction could accurately differentiate between adrenal aldosterone-producing nodules and nonfunctioning nodules. It might serve as a noninvasive alternative to adrenal vein sampling in primary aldosteronism patients with bilateral adrenal nodules. KEY POINTS: • Conventional CT cannot differentiate aldosterone-producing adrenal nodules from nonfunctioning nodules. • Extracellular volume of adrenal aldosterone-producing nodules was significantly lower than that of nonfunctioning nodules and normal adrenal glands. It can accurately differentiate between aldosterone-producing and nonfunctioning adrenal nodules. • Extracellular volume may be a novel, noninvasive biomarker alternative to adrenal vein sampling for determining the functional status of bilateral adrenal nodules in patients with primary aldosteronism.

Predicting Bilateral Subtypes of Primary Aldosteronism Without Adrenal Vein Sampling: A Systematic Review and Meta-analysis.

CONTEXT: Primary aldosteronism (PA) is the most common endocrine cause of hypertension. The final diagnostic step involves subtyping, using adrenal vein sampling (AVS), to determine if PA is unilateral or bilateral. The complete PA diagnostic process is time and resource intensive, which can impact rates of diagnosis and treatment. Previous studies have developed tools to predict bilateral PA before AVS. OBJECTIVE: Evaluate the sensitivity and specificity of published tools that aim to identify bilateral subtypes of PA. METHODS: Medline and Embase databases were searched to identify published models that sought to subtype PA, and algorithms to predict bilateral PA are reported. Meta-analysis and meta-regression were then performed. RESULTS: There were 35 studies included, evaluating 55 unique algorithms to predict bilateral PA. The algorithms were grouped into 6 categories: those combining biochemical, radiological, and demographic characteristics (A); confirmatory testing alone or combined with biochemical, radiological, and demographic characteristics (B); biochemistry results alone (C); adrenocorticotropic hormone stimulation testing (D); anatomical imaging (E); and functional imaging (F). Across the identified algorithms, sensitivity and specificity ranged from 5% to 100% and 36% to 100%, respectively. Meta-analysis of 30 unique predictive tools from 32 studies showed that the group A algorithms had the highest specificity for predicting bilateral PA, while group F had the highest sensitivity. CONCLUSIONS: Despite the variability in published predictive algorithms, they are likely important for decision-making regarding the value of AVS. Prospective validation may enable medical treatment upfront for people with a high likelihood of bilateral PA without the need for an invasive and resource-intensive test.

Asymmetric Adrenals: Sexual Dimorphism of Adrenal Tumors.

CONTEXT: Sexual dimorphism has direct consequences on the incidence and survival of cancer. Early and accurate diagnosis is crucial to improve prognosis. OBJECTIVE: This work aimed to characterized the influence of sex and adrenal asymmetry on the emergence of adrenal tumors. METHODS: We conducted a multicenter, observational study involving 8037 patients with adrenal tumors, including adrenocortical carcinoma (ACC), aldosterone-producing adenoma (APA), cortisol-secreting adrenocortical adenomas (CSAs), non-aldosterone-producing adrenal cortical adenoma (NAPACA), pheochromocytoma (PCC), and neuroblastoma (NB), and investigated tumor lateralization according to sex. Human adrenal tissues (n = 20) were analyzed with a multiomics approach that allows determination of gene expression, catecholamine, and steroid contents in a single sample. In addition, we performed a literature review of computed tomography and magnetic resonance imaging-based studies examining adrenal gland size. RESULTS: ACC (n = 1858); CSA (n = 68), NAPACA (n = 2174), and PCC (n = 1824) were more common in females than in males (female-to-male ratio: 1.1:1-3.8:1), whereas NBs (n = 2320) and APAs (n = 228) were less prevalent in females (0.8:1). ACC, APA, CSA, NAPACA, and NB occurred more frequently in the left than in the right adrenal (left-to-right ratio: 1.1:1-1.8:1), whereas PCC arose more often in the right than in the left adrenal (0.8:1). In both sexes, the left adrenal was larger than the right adrenal; females have smaller adrenals than males. CONCLUSION: Adrenal asymmetry in both sexes may be related to the pathogenesis of adrenal tumors and should be considered during the diagnosis of these tumors.

Clinical Value of 68Ga-Pentixafor PET/CT in Subtype Diagnosis of Primary Aldosteronism Patients with Adrenal Micronodules.

Our objective was to investigate the clinical value of 68Ga-pentixafor PET/CT in subtype diagnosis of primary aldosteronism (PA) patients with adrenal micronodules less than 1 cm in diameter and compare it with the routine clinical methods. Methods: We used prospective enrollment of PA patients with adrenal micronodules identified by adrenal CT scans to undergo 68Ga-pentixafor PET/CT. Patients were divided into surgically eligible and ineligible groups based on surgical pathology and postoperative follow-up or adrenal venous sampling (AVS) results. Patient management was discussed by a multidisciplinary team. The semiquantitative parameters of PET/CT included SUVmax for adrenal lesion and SUV ratios for lesion to liver and lesion to normal adrenal gland. Results: In total, 123 PA patients with adrenal micronodules were examined using 68Ga-pentixafor PET/CT, and 104 patients who underwent surgery or successful AVS were included in the analysis (48 ± 10 y old). The sensitivity, specificity, and accuracy of visual analysis using 68Ga-pentixafor PET/CT to identify surgically eligible patients were 90.2%, 72.7%, and 86.5%, respectively, which were significantly higher than those of adrenal CT (73.1%, 53.8%, and 68.3%, respectively) and yielded consistent results in different CT morphologic or age subgroups. In 36 patients who had both AVS and 68Ga-pentixafor PET/CT, the tests showed a 66.7% concordance rate. However, PET/CT was significantly more concordant with surgical outcomes than was AVS in 17 patients who underwent adrenalectomy (82.4% vs. 68.86%). Among the 183 adrenal micronodules included in the study, the semiquantitative diagnostic thresholds for 92 lesions eligible for surgical treatment were an SUVmax of at least 4.55, an SUV ratio of at least 2.17 for lesion to liver, and an SUV ratio of at least 1.90 for lesion to normal adrenal gland. All patients benefited from surgical removal of 68Ga-pentixafor-avid microlesions. Conclusion: In PA patients with adrenal micronodules, 68Ga-pentixafor PET/CT demonstrated promising diagnostic accuracy in classification and appeared to perform better than adrenal CT. Furthermore, there was also a suggestion of some potential in predicting postoperative efficacy compared with AVS, although these observations require further investigation and verification in larger cohorts.

Ectopic adrenal tissue in a cat that underwent an ovariohysterectomy.

OBJECTIVE: To describe the use of ultrasound and adrenal function testing to confirm that excised periovarian tissue is normal ectopic adrenal tissue (EAT). ANIMAL: A 6-month-old female domestic shorthair cat. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The cat underwent an ovariohysterectomy procedure, during which abnormal tissue was discovered adjacent to both ovaries. The tissue was removed during the ovariohysterectomy and submitted for histopathology, which was consistent with adrenal gland tissue, initially raising concern for an inadvertent adrenalectomy. Abdominal ultrasound and an adrenal function test were performed that confirmed normal adrenal structure and function; thus, the removed structure was diagnosed as EAT. TREATMENT AND OUTCOME: The patient continued to recover from the procedure uneventfully at home. CLINICAL RELEVANCE: Parovarian nodules are an uncommon finding but when observed and biopsied, may be mistaken for physiologic adrenal tissue on the basis of histopathologic features alone without awareness of their existence and clinical context. The use of abdominal ultrasound and ACTH stimulation test offers an affirmative method of differentiating adrenal gland tissue from EAT.

MCNet: A multi-level context-aware network for the segmentation of adrenal gland in CT images.

Accurate segmentation of the adrenal gland from abdominal computed tomography (CT) scans is a crucial step towards facilitating the computer-aided diagnosis of adrenal-related diseases such as essential hypertension and adrenal tumors. However, the small size of the adrenal gland, which occupies less than 1% of the abdominal CT slice, poses a significant challenge to accurate segmentation. To address this problem, we propose a novel multi-level context-aware network (MCNet) to segment adrenal glands in CT images. Our MCNet mainly consists of two components, i.e., the multi-level context aggregation (MCA) module and multi-level context guidance (MCG) module. Specifically, the MCA module employs multi-branch dilated convolutional layers to capture geometric information, which enables handling of changes in complex scenarios such as variations in the size and shape of objects. The MCG module, on the other hand, gathers valuable features from the shallow layer and leverages the complete utilization of feature information at different resolutions in various codec stages. Finally, we evaluate the performance of the MCNet on two CT datasets, including our clinical dataset (Ad-Seg) and a publicly available dataset known as Distorted Golden Standards (DGS), from different perspectives. Compared to ten other state-of-the-art segmentation methods, our MCNet achieves 71.34% and 75.29% of the best Dice similarity coefficient on the two datasets, respectively, which is at least 2.46% and 1.19% higher than other segmentation methods.

Diagnostic consistency between computed tomography and adrenal vein sampling of primary aldosteronism: leading to successful curative outcome after adrenalectomy; a retrospective study.

BACKGROUND: Adrenal computed tomography (CT) is a useful tool for locating adrenal lesion in primary aldosteronism (PA) patients. However, adrenal vein sampling (AVS) is considered as a gold standard for subtype diagnosis of PA. The aim of this study was to investigate the consistency of CT and AVS for the diagnosis of PA subtypes and evaluate the concordance of surgical outcomes. MATERIALS AND METHODS: This retrospective study included 264 PA patients having both CT and AVS. Diagnostic consistency between CT and AVS was accessed, and clinical and biochemical outcomes were evaluated at 6 months after adrenalectomy. RESULTS: Of all, 207 (78%) had a CT unilateral lesion, 31 (12%) CT bilateral lesion, and 26 (10%) CT bilateral normal findings. Among the CT unilateral lesion group, 138 (67%) had ipsilateral AVS lateralization. For CT bilateral lesion and bilateral normal, AVS unilateral lateralization was found in 17 (55%) and 2 (8%), respectively. The consistency between CT lesion and AVS lateralization including CT unilateral with AVS ipsilateral, and CT bilateral lesion with AVS bilateral patients was 63.8% (152/238). Of 77 patients with available data out of 138 patients who underwent adrenalectomy with consistency between CT and AVS, the clinical success rate was 96%, for 17 inconsistency patients out of 22 patients who underwent adrenalectomy, the clinical success rate was 94% after adrenalectomy following the lateralization result of AVS. CONCLUSION: CT is a useful tool to diagnose the adrenal lesion in PA patients. However, AVS is more sufficient to detect the unilateral PA subtype, which could provide curable treatment to surgical candidates of PA such that AVS can identify patients with contralateral PA in CT unilateral lesion and unilateral PA in CT bilateral lesion. The surgical outcome was successful when an adrenalectomy was performed according to the AVS lateralization result.

Current perspectives on the diversification of endoscopic ultrasound-guided fine-needle aspiration and biopsy.

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has undergone significant advancements since it was first reported in 1992. Initially focused on the pancreas, EUS-guided fine-needle aspiration (FNA) has now been extended to encompass all organs proximal to the gastrointestinal system. Recently, a novel fine-needle biopsy (FNB) needle with an end-cut tip was developed, allowing for the collection of specimens suitable for histological assessment, a feat hard to achieve with traditional needles. The FNB needle holds promise for applications in immunohistochemistry staining and genetics evaluation, and it has the potential to yield specimens of comparable quality to core needle biopsy during percutaneous puncture, especially for lesions beyond the pancreas, such as lymph nodes. This review focuses on the efficacy of EUS-FNA/FNB for extended target regions, specifically lymph nodes, spleen, adrenal gland, and ascites. The indications for EUS-FNA have greatly expanded beyond the pancreas over the years, and future improvements and innovations in puncture needles will allow for the collection of higher-quality specimens, which is expected to play a significant part in personalized cancer treatment.