MRI of the adrenal gland

Pheochromocytoma

Pheochromocytomas are rare tumors originating in the adrenal medulla. They may be sporadic or in the context of a hereditary syndrome. A considerable number of pheochromocytomas carry germline or somatic gene mutations, which are inherited in the autosomal dominant way. All patients should undergo genetic testing. Symptoms are due to catecholamines over production or to a mass effect. Diagnosis is confirmed by raised plasma or urine metanephrines or normetanephrines. Radiology assists in the tumor location and any local invasion or metastasis. All the patients should have preoperative preparation with α-blockers and/or other medications to control hypertension, arrhythmia, and volume expansion. Surgery is the definitive treatment. Follow up should be life-long.

Endocrine causes of hypertension in pregnancy

Hypertension is a common and morbid complication of pregnancy. While endocrine causes of secondary hypertension are not rare, women with these conditions do not often conceive, and even less commonly are these disorders diagnosed during pregnancy. This review will consider conditions of adrenal hormone excess that cause secondary hypertension: primary aldosteronism (PA), Cushing syndrome (CS), and pheochromocytoma/paraganglioma. We emphasize that pregnancy itself elicits changes in the regulation of aldosterone and cortisol production and standard endocrine testing algorithms. Furthermore, conventional imaging modalities and pharmacotherapies are often contraindicated in pregnancy, which complicates diagnosis and management. Nevertheless, surgical management in the second trimester is the preferred treatment strategy for most of these rare cases when feasible. This article will discuss the approach to patients with endocrine causes of hypertension during pregnancy with emphasis on those aspects that deviate from the assessment and treatment of non-pregnant patients.

Pheochromocytoma, diagnosis and treatment: Review of the literature

Objective. We conducted an extensive review of the literature and tried to cite the most recent recommendations concerning the pheochromocytoma (PHEO).

Methods. Pub Med and Google Scholar databases were searched systematically for studies concerning pheochromocytomas (intra-adrenal paragangliomas) from 1980 until 2016. Bibliographies were searched to find additional articles.

Results. More than four times elevation of plasma fractionated metanephrines or elevated 24-h urinary fractionated metanephrines are keys to diagnosing pheochromocytoma. If the results are equivocal then we perform the clonidine test. If we have not done it already, we preferably do a CT scan and/or an MRI scan. The patient needs pre-treatment with α1-blockers at least 10–14 days before operation. Alternatives or sometimes adjuncts are Calcium Channels Blockers and/or β-Blockers. Several familial syndromes are associated with PHEO and genetic testing should be considered.

Conclusions. The biggest problem for pheochromocytoma is to suspect it in the first place. Elevated metanephrines establish the diagnosis. With the proper preoperative preparation the risks during operation and the postoperative period are minimal. If there is a risk of the hereditable mutation, it is strongly suggested that all the patients with pheochromocytoma need clinical genetic testing.

Magnetic resonance imaging of the presumed normal canine adrenal glands

Forty-three dogs without evidence of endocrine disease that underwent spinal or abdominal magnetic resonance imaging (MRI) for clinical reasons were studied. Because the procedures were not optimized for inclusion of the adrenal glands, they were not always visible in all planes. Eighty-five of the 86 adrenal glands were seen and only the left gland in a 6-month-old Irish wolfhound could not be found. The right adrenal gland lay cranial to the left in all of the animals in which both glands were seen. The best landmarks for localization of the glands were vascular; both adrenal glands were always cranial to the ipsilateral renal vessels and in the region of the celiac and cranial mesenteric arteries. Various measurements were made on all the available scan planes. In some dogs the whole adrenal gland was difficult to visualize clearly, and this hindered the measuring process, especially when the right adrenal gland was in close contact with the caudal vena cava. The adrenal glands were mainly linear in shape but also had a variable degree of modification of their poles, especially the cranial pole of the right adrenal gland, which tended to be consistently wider and to present different shapes (rounded, arrowhead, inverted P, hook-shaped, triangular, or dome-shaped). Two main patterns of signal intensity were seen on fast spin echo (FSE) sequences (T2-weighted, T1-weighted, and T1-weighted after administration of a paramagnetic contrast medium): homogeneous and hypointense to surroundings or a corticomedullary type pattern with a hyperintense central area surrounded by a hypointense rim of tissue. The outline of the left adrenal gland was always very clear. The clarity of outline of the right adrenal gland was more variable, especially if it was in contact with the liver or the caudal vena cava. It was felt that the amount of retroperitoneal fat was not as important as stated in the human literature for visualization of the adrenal glands and that with an appropriate selection of scan planes and pulse sequences good assessment of the adrenal glands can be performed with MRI in canine patients.

Endocrine causes of hypertension in pregnancy--when to start looking for zebras

Hypertension is a common medical disorder in pregnancy that may predate or first appear in pregnancy. Endocrine disorders rarely are the cause of the elevated blood pressure. However, it is essential to have a high index of suspicion because they carry much higher fetal and maternal morbidity and mortality risks. Endocrine disorders presenting as hypertension are primarily the result of autonomous production of renin, aldosterone, cortisol, or catecholamines. This report discusses the physiological changes in pregnancy, presentation, investigation, and management of these disorders.

Magnetic resonance findings in sarcoidosis of the thorax

Fifteen patients with sarcoidosis underwent thoracic MRI examinations. The T2 signal intensity of lymphadenopathy varied, with no characteristic pattern noted. Three of four patients with bright lymph nodes on T2 images had stage I sarcoidosis, but low intensity nodes were also seen in stage I patients. Coronal images were complementary to axial images and better depicted subcarinal adenopathy. MRI does not distinguish the lymphadenopathy of sarcoidosis from other entities, but is useful for defining the anatomic extent of disease and differentiating pulmonary artery enlargement from adenopathy.

Magnetic resonance imaging of the adrenal gland in women with late-onset adrenal hyperplasia

To determine the presence of structural abnormalities of the adrenal in late-onset adrenal hyperplasia, four consecutive patients were studied by MRI before beginning glucocorticoid replacement therapy. Three women were diagnosed as 21-hydroxylase deficient late-onset adrenal hyperplasia by a 17-OHP level greater than 1,000 ng/dL 30 minutes after acute adrenal stimulation, and one patient was diagnosed as 11-hydroxylase deficient late-onset adrenal hyperplasia when her 11-deoxycortisol level was threefold the upper 95th percentile of normal. Two patients with 21-hydroxylase deficient late-onset adrenal hyperplasia had normal adrenal glands on MRI. Another 21-hydroxylase deficient late-onset adrenal hyperplasia patient was noted to have a 2.5 x 3.3-cm left adrenal nodule, which had been documented some 4 years earlier on CT scan and had not changed in size during that interval. This patient was 40 years of age when the diagnosis of late-onset adrenal hyperplasia was established. The patient with 11-hydroxylase deficient late-onset adrenal hyperplasia demonstrated a diffuse enlargement of the left adrenal gland consistent with hyperplasia, with no focal lesions. In conclusion, although patients with late-onset adrenal hyperplasia may often demonstrate nodular or diffuse adrenocortical hyperplasia on MRI, not all patients with endocrinologically evident disease demonstrate such abnormalities, consistent with a lesser degree of ACTH stimulation compared with women with classical congenital adrenal hyperplasia.