Adrenal Imaging with MDCT: Nonneoplastic Disease

Primary adrenal insufficiency induced by immune checkpoint inhibitors: biological, clinical, and radiological aspects

Immune checkpoint inhibitors (ICI) have become a cornerstone in medical oncology, with evolving therapeutic strategies and applications. These monoclonal antibodies, designed to enhance immune responses, have revealed a spectrum of immune-related adverse events (irAEs). While many irAEs exhibit favorable responses to corticosteroid or immunosuppressive therapy, most ICI-related endocrinopathies necessitate lifelong replacement therapy and pose significant clinical challenges. Adrenal insufficiency (AI), a noteworthy endocrine irAE, can manifest as primary AI (PAI) or secondary AI (SAI), resulting from adrenal or pituitary gland dysfunction, respectively. ICI-induced AI, albeit relatively infrequent, occurs in 1-2% of patients receiving single-agent anti-Programmed Death-1/Programmed Death-Ligand 1 (PD-1/PD-L1) or Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) therapies and in a higher range of 4-9% when ICIs are used in combinations. Recognizing and addressing ICI-induced PAI is crucial, as it often presents with acute and potentially life-threatening symptoms, especially considering the expanding use of ICI therapy. This review provides an updated overview of ICI-induced PAI, exploring its clinical, diagnostic, and radiological aspects.

Application of DKI and IVIM imaging in evaluating histologic grades and clinical stages of clear cell renal cell carcinoma

Purpose

To evaluate the value of quantitative parameters derived from diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) in differentiating histologic grades and clinical stages of clear cell renal cell carcinoma (ccRCC).

Materials and methods

A total of 65 patients who were surgically and pathologically diagnosed as ccRCC were recruited in this study. In addition to routine renal magnetic resonance imaging examination, all patients underwent preoperative IVIM and DKI. The corresponding diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), mean diffusivity (MD), kurtosis anisotropy (KA), and mean kurtosis (MK) values were obtained. Independent-samples t-test or Mann-Whitney U test was used for comparing the differences in IVIM and DKI parameters among different histologic grades and clinical stages. The diagnostic efficacy of IVIM and DKI parameters was evaluated using the receiver operating characteristic (ROC) curve. Spearman's correlation analysis was used to separately analyze the correlation of each parameter with histologic grades and stages of ccRCC.

Results

The D and MD values were significantly higher in low-grade ccRCC than high-grade ccRCC (all p < 0.001) and in low-stage than high-stage ccRCC (all p < 0.05), and the f value of high-stage ccRCC was lower than that of low-stage ccRCC (p = 0.007). The KA and MK values were significantly higher in low-grade than high-grade ccRCC (p = 0.000 and 0.000, respectively) and in low-stage than high-stage ccRCC (p = 0.000 and 0.000, respectively). The area under the curve (AUC) values of D, D*, f, MD, KA, MK, DKI, and IVIM+DKI values were 0.825, 0.598, 0.626, 0.792, 0.750, 0.754, 0.803, and 0.857, respectively, in grading ccRCC and 0.837, 0.719, 0.710, 0.787, 0.796, 0.784, 0.864, 0.823, and 0.916, respectively, in staging ccRCC. The AUC of IVIM was 0.913 in staging ccRCC. The D, D*, and MD values were negatively correlated with the histologic grades and clinical stages (all p < 0.05), and the KA and MK values showed a positive correlation with histologic grades and clinical stages (all p < 0.05). The f value was also negatively correlated with the ccRCC clinical stage (p = 0.008).

Conclusion

Both the IVIM and DKI values can be used preoperatively to predict the degree of histologic grades and stages in ccRCC, and the D and MD values have better diagnostic performance in the grading and staging. Also, further slightly enhanced diagnostic efficacy was observed in the model with combined IVIM and DKI parameters.

Adrenal Tuberculosis: A Case Report and Literature Review

Adrenal tuberculosis (TB) is a rare disease, which is difficult to diagnose because of its atypical symptoms. We reported a 41-year-old female who was admitted to hospital due to a left adrenal tumor, which was found in health examination without any symptoms. Abdominal CT showed a mass in her left adrenal. The results of blood test were normal. A retroperitoneal laparoscopic adrenalectomy was carried out, and adrenal TB was finally pathologically diagnosed. Following this, examinations focusing on TB were conducted which revealed negative results except for T-cell enzyme-linked immunospot. After the operation, the hormone level was normal. However, a wound infection occurred, which was recovered after antituberculosis treatment. In conclusion, even if there is no evidence of TB, we should be alert when diagnosing adrenal masses. Examinations of pathology, radiography, and hormone play important roles in determining the definite diagnosis of adrenal TB.

Cross-sectional imaging features of unusual adrenal lesions: a radiopathological correlation

The detection rates of adrenal masses are increasing with the common and widespread use of cross-sectional imaging. Adrenal adenomas, myelolipomas, metastases, pheochromocytomas, and adrenocortical tumors are well-known and relatively common adrenal tumors. However, there are many less-known neoplastic and nonneoplastic adrenal diseases that might affect the adrenal glands in addition to these common lesions. These rare entities include, but are not limited to, hydatid cysts, congenital adrenal hyperplasia, Wolman disease, adrenal tuberculosis, primary adrenal lymphoma. This article aims to present imaging findings of these unusual lesions in accordance with their pathologic characteristics. We think that the simultaneous presentation of the pathological findings with the imaging features may facilitate the learning process and may potentially enhance the recognition of these entities.

Mimics, pitfalls, and misdiagnoses of adrenal masses on CT and MRI

Due to the widespread use of imaging, incidental adrenal masses are commonly encountered. A number of pitfalls can result in misdiagnosis of these lesions, including inappropriate choice of imaging technique, presence of pseudolesions, and overlap of imaging features of different adrenal lesions. This article explores the potential pitfalls in imaging of the adrenal glands, on computed tomography and magnetic resonance imaging, that can lead to misinterpretation. Clues to correct diagnoses are provided to evade potential misinterpretation.

Case 268: Bilateral Adrenal Hemorrhage in the Context of Sepsis

History A 65-year-old man presented to the emergency department with a 1-week history of constipation, which was associated with increasing abdominal distention and not passing flatus. Four weeks prior to the current admission he had been diagnosed with metastatic primary adenocarcinoma of the appendix. One week ago, he had been hospitalized with small-bowel obstruction, for which he required laparotomy and loop ileostomy. His medical history included basal cell carcinoma, rheumatoid arthritis, and Barrett esophagus. Physical examination revealed a distended abdomen with tenderness at palpation within the right upper quadrant and lower abdomen and reduced bowel sounds at auscultation. Initial plain-film radiography of the abdomen at admission revealed dilated gas-filled small-bowel loops, suggestive of obstruction. His small-bowel obstruction was managed conservatively on this occasion. Nine days after admission, the patient became unwell and reported a productive cough. He became tachycardic, tachypneic, and hypotensive. Relevant blood tests at this stage revealed a C-reactive protein level of 206 mg/L (normal range, 0-10 mg/L), a white blood cell count of 24.5 × 10⁹/L (normal range, [4.0-11.0] × 10⁹/L), a red blood cell count of 3.39 × 10¹²/L (normal range, [4.5-5.5] × 10¹²/L), a hemoglobin level of 93 g/L (normal range, 130-170 g/L), and a hematocrit level of 0.27 (normal range, 0.4-0.5). CT of the abdomen and pelvis with intravenous contrast material (100 mL Omnipaque 350; GE Healthcare, Oslo, Norway) was performed.

Surgical Management of a Giant Adrenal Pseudocyst: A Case Report and Review of the Literature in the Last Decade

Adrenal pseudocysts are rare entities and occurred in the 5th and the 6th decades of life. They are discovered accidentally, while appearing with nonspecific clinical and imaging findings. We report a case of a 28-year-old woman presented in our Emergency Department complaining about upper abdomen pain. Computed tomography revealed a hypodense cystic lesion containing hyperdense material. The size of a mass was 11. 7 × 9.3 × 6.6 cm in diameter close to the pancreas, but the origin was from the left adrenal gland. The mass was excised with surgical laparotomy. Giant adrenal pseudocysts are rare entities. Final diagnosis usually confirmed with the pathology examination. Management of such adrenal lesions depends on the unique characteristics, the surgeon's experience, and local resources.

Targeted Molecular Imaging in Adrenal Disease-An Emerging Role for Metomidate PET-CT

Adrenal lesions present a significant diagnostic burden for both radiologists and endocrinologists, especially with the increasing number of adrenal ‘incidentalomas’ detected on modern computed tomography (CT) or magnetic resonance imaging (MRI). A key objective is the reliable distinction of benign disease from either primary adrenal malignancy (e.g., adrenocortical carcinoma or malignant forms of pheochromocytoma/paraganglioma (PPGL)) or metastases (e.g., bronchial, renal). Benign lesions may still be associated with adverse sequelae through autonomous hormone hypersecretion (e.g., primary aldosteronism, Cushing’s syndrome, phaeochromocytoma). Here, identifying a causative lesion, or lateralising the disease to a single adrenal gland, is key to effective management, as unilateral adrenalectomy may offer the potential for curing conditions that are typically associated with significant excess morbidity and mortality. This review considers the evolving role of positron emission tomography (PET) imaging in addressing the limitations of traditional cross-sectional imaging and adjunctive techniques, such as venous sampling, in the management of adrenal disorders. We review the development of targeted molecular imaging to the adrenocortical enzymes CYP11B1 and CYP11B2 with different radiolabeled metomidate compounds. Particular consideration is given to iodo-metomidate PET tracers for the diagnosis and management of adrenocortical carcinoma, and the increasingly recognized utility of ¹¹C-metomidate PET-CT in primary aldosteronism.

Pediatric adrenal trauma: evaluation and follow-up with contrast-enhanced ultrasound (CEUS)

Adrenal trauma is rarely encountered in the pediatric population, often as a component of multi-organ injury and often presenting with hematoma formation. Contrast-enhanced computed tomography (CECT) is the established imaging modality both for initial evaluation and follow-up of patients with blunt abdominal trauma. In children, radiation exposure should be minimized and alternative imaging strategies are needed. Contrast-enhanced ultrasound (CEUS) has recently been successfully used for evaluation of patients with hepatic, renal and splenic injury. We present three cases of children with post-traumatic adrenal hematomas, which were initially diagnosed with CECT and subsequently followed up with CEUS, suggesting that CEUS may be considered for follow-up of adrenal injuries in children. CEUS improves the diagnostic capabilities by increasing tissue contrast and spatial resolution, readily differentiating viable from necrotic tissue in comparison to conventional ultrasound without the risk of iodine contrast agents and ionizing radiation of repeated CECT examinations.

Adrenal disease: a clinical update and overview of imaging. A review

AIM

The aim of this article is to provide an overview of the most frequent clinically significant adrenal diseases and to describe the latest trends in their diagnostics, particularly by means of imaging techniques.

METHODS

The authors reviewed standard textbooks and subsequently conducted a search using the PubMed (Public/Publisher MEDLINE) electronic database by the year 2013 with the following search terms: adrenal masses, adrenal adenoma, phaeochromocytoma, adrenocortical carcinoma, metastases, incidentalomas, hypercortisolism, hyperaldosteronism.

RESULTS

If adrenal disease is clinically suspected, hormone tests are performed to detect adrenal hyperfunction and imaging studies are used to assess the nature of adrenal lesion. The most frequent syndromes include hypercortisolism, primary hyperaldosteronism, and phaeochromocytoma. The clinically most significant pathologies of the adrenal glands are adenomas and adrenal hyperplasia, adrenocortical carcinomas, phaeochromocytomas, and metastases. Given the availability and improved quality of imaging techniques, adrenal incidentalomas are detected increasingly often. In these cases, it is necessary to rule out hormonal activity and malignancy. Incidentalomas can be associated with clinical syndromes of adrenal hormone overproduction. In most cases, they are clinically silent. In some cases, the definitive diagnosis can be determined as early as during the initial examination with an imaging technique (most frequently, a CT scan). If the finding is inconsistent, other imaging techniques can be used: CT contrast washout analysis, MRI, SPECT or PET/CT.

CONCLUSION

In the case of adrenal gland disorders, correct interpretation of the results of laboratory tests and imaging studies is essential for further management of these patients.

Prostate gland development and adrenal tumor in a female with congenital adrenal hyperplasia: a case report and review from radiology perspective

We describe a case of a female with simple virilizing congenital adrenal hyperplasia (CAH) reared as a male diagnosed at the late age of 64. Computed Tomography (CT) demonstrated a large adrenal mass, bilateral diffuse adrenal enlargement, female pelvic organs as well as a clearly visualized prostate gland. This is to the best of our knowledge the first case of such a sizable prostate gland in a female CAH patient documented on CT. We review the literature regarding aspects where radiologists may encounter CAH and the finding of presence of a prostate gland in female CAH patients.

Radiological evaluation of adrenal incidentalomas: current methods and future prospects

Incidental adrenal lesions are very common. Computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) all have a role to play in characterizing adrenal lesions. The purpose of this review is to discuss the rationale behind both established and emerging imaging techniques. We also discuss how to follow up incidentally found lesions.

Adrenal hematoma after nephrectomy

OBJECTIVE

The objective of our study was to retrospectively define the incidence of adrenal hematoma on CT or MRI after nephrectomy.

MATERIALS AND METHODS

Between January 2008 and June 2009, 465 patients underwent nephrectomy at our institution. Of these, patients without both preoperative and postoperative abdominal CT or MR studies within 6 months of surgery (n = 83) and those with documented adrenalectomy at the time of radical nephrectomy (n = 33) were excluded. Thus, 349 patients (292 male, 57 female; mean age, 60.2 years; range, 2-88 years) were included in the study. Preoperative and postoperative CT or MR studies were reviewed by two radiologists in consensus for the presence or absence of adrenal hematoma. Diagnosis of adrenal hematoma was made by imaging findings and follow-up. The incidence of adrenal hematoma was calculated with a 95% CI.

RESULTS

Of the 349 patients (partial nephrectomy, n = 232; radical nephrectomy, n = 117), 19 patients developed adrenal hematoma after nephrectomy (partial nephrectomy, n = 12; radical nephrectomy, n = 7) with an incidence of 5.4% (95% CI, 3.1-7.8%). All adrenal hematomas were located on the side of nephrectomy (right adrenal gland, n = 8; left adrenal gland, n = 11). In nine patients, the adrenal hematoma appeared as a round or oval lesion on postoperative imaging with a mean size of 2.6 cm (range, 1.5-4.0 cm). In 10 patients, the adrenal hematoma appeared as diffuse enlargement of the adrenal gland on postoperative imaging with a mean thickness of 1.3 cm (range, 0.6-1.8 cm).

CONCLUSION

An adrenal hematoma was identified in 5.4% of patients on CT or MRI after nephrectomy. A new round or oval adrenal mass after nephrectomy should be differentiated from a metastasis.

Adrenal imaging

OBJECTIVE

Adrenal nodules are frequently encountered on current high-resolution imaging, and accurate characterization of such lesions is critical for appropriate patient care. Our article highlights how imaging techniques such as CT densitometry, CT washout characteristics, chemical shift MRI, PET, and PET/CT help characterize most adrenal lesions. We focus on these techniques as well as specifically, because of space constraints, the varied imaging appearances of adrenocortical carcinoma, pheochromocytoma, and lymphoma on these techniques.

CONCLUSION

The imaging characterization of adrenal lesions has continued to advance over the past decade as new technologies have evolved. CT, MRI, PET, and PET/CT are now established clinical techniques capable of differentiating benign from malignant adrenal lesions.