Adrenal glands in beta-thalassemia major: magnetic resonance (MR) imaging features and correlation with iron stores

Abstract

This study aimed at describing the magnetic resonance (MR) imaging features of the adrenal glands in beta-thalassemic patients and at investigating the relation between adrenal and hepatic siderosis. Adrenal signal intensity (SI) was retrospectively assessed on abdominal MR studies of 35 patients with beta-thalassemia major undergoing quantification of hepatic siderosis and 12 healthy controls, using T1-(120/4/90), intermediate-(120/4/20), and T2*-(120/15/20) weighted GRE sequences. Adrenal SI was graded as grade 0 (normal SI on all sequences), grade 1 (hypointensity on T2* alone), or grade 2 (hypointensity on at least T2*). Adrenal size was measured in the thalassemic patients and compared with normative data. Liver-to-muscle (L/M) SI ratios, expressing hepatic siderosis, were estimated on each sequence. Serum ferritin levels were recorded. Adrenal hypointensity (grades 1 and 2) was noted in 24/35 (68.6%) patients. L/M ratios correlated significantly with adrenal SI in all sequences. Patients with grade 1 and grade 2 adrenal SI had significantly decreased L/M ratios compared with grade 0. Serum ferritin correlated significantly with L/M values but not with adrenal SI. Adrenal size was within normal limits. Diffuse hypointensity in normal-sized adrenals is a common MR finding in beta-thalassemic patients and correlates with the degree of hepatic siderosis.

A Review of Endocrine Disorders in Thalassaemia

“…Imaging studies using MR have frequently identified adrenal hypointensity without alteration of morphology in thalassaemia patients and verified autopsy findings of correlation between adrenal iron and liver iron [94]. However, despite high sensitivity, histology still remains the gold standard for diagnosis of iron deposition.…”

Magnetic Resonance Imaging Assessment of Excess Iron in Thalassemia, Sickle Cell Disease and Other Iron Overload Diseases

“…Target Organ-Although MRI is most often used to estimate cardiac and hepatic iron, MRI can also been used to characterize tissue iron deposits in the brain, pituitary gland, bone marrow, kidney and pancreas (36)(37)(38)(39)(40)(41)(42). These approaches observe the same physical principles as cardiac and hepatic iron imaging but present different imaging challenges.…”

“…In contrast, splenic iron deposits are quite large and spin-echo (R2) techniques will not yield accurate iron estimates in this organ. The merits and limitations of these other techniques are beyond the scope of this manuscript, but several key references are included for interested readers (36)(37)(38)(39)(40)(41)(42).…”

Magnetic resonance imaging measurement of iron overload

“…MRI has also been used to characterize tissue iron deposits in the brain, pituitary gland, bone marrow, kidney and pancreas [65][66][67][68][69][70][71]. Although less well validated and clinically exploited, these approaches are likely to become increasingly important in the assessment of transfusional iron overload.…”