Liver, bone marrow, pancreas and pituitary gland iron overload in young and adult thalassemic patients: a T2 relaxometry study

Abstract

Thirty-seven patients with beta-thalassemia major, including 14 adolescents (15.2 +/- 3.0 years) and 23 adults (26.4 +/- 6.9 years), were studied. T2 relaxation time (T2) of the liver, bone marrow, pancreas and pituitary gland was measured in a 1.5-Tesla magnetic resonance (MR) imager, using a multiecho spin-echo sequence (TR/TE 2,000/20, 40, 60, 80, 100, 120, 140, 160 ms). Pituitary gland height was evaluated in a midline sagittal scan of a spin-echo sequence (TR/TE, 500/20 ms). The T2 of the pituitary gland was higher in adolescents (59.4 +/- 15 ms) than in adults (45.3 +/- 10.4 ms), P < 0.05. The T2 of the pancreas was lower in adolescents (43.6 +/- 10.3 ms) than in adults (54.4 +/- 10.4 ms). No difference among groups was found in the T2 of the liver and bone marrow. There was no significant correlation of the T2 among the liver, pancreas, pituitary gland and bone marrow. There was no significant correlation between serum ferritin and T2 of the liver, pancreas and bone marrow. Pituitary T2 showed a significant correlation with pituitary gland height (adolescents: R = 0.63, adults: R = 0.62, P < 0.05) and serum ferritin (adolescents: R = -0.60, adults: R = -0.50, P < 0.05). In conclusion, iron overload evaluated by T2 is organ specific. After adolescence, age-related T2 changes are predominantly associated with pituitary siderosis and fatty degeneration of the pancreas. Pituitary size decreases with progressing siderosis.

Regional and global pancreatic T*2 MRI for iron overload assessment in a large cohort of healthy subjects: Normal values and correlation with age and gender

“…For the pancreatic evaluation we did not apply fat saturation, used by Schwenzer et al (8). In fact, Argyropoulou et al suggested that the T 2 relaxation time depends not only on siderosis but also on the fatty infiltration of the pancreatic parenchyma (10). The multiecho sequence used in this study (10 echoes in-and out-phase) may reduce the influence of the signal fluctuation due to fat-parenchymal interface (11).…”

Investigation of Unmedicated Early Onset Restless Legs Syndrome by Voxel-Based Morphometry, T2 Relaxometry, and Functional MR Imaging during the Night-Time Hours

“…31 This is not in contradiction with the results of the current study because ferritin does not cross the blood-brain barrier; therefore, its serum levels are not a good index of brain iron burden. 18,32 Although iron is critical in brain metabolism, increased iron deposition occurs in brain areas undergoing degeneration. 9,17,33 According to the currently accepted model of functional neuroanatomy, the globus pallidus external, through excitatory D2 receptors, receives GABAergic inhibitory projections from the striatum, and the STN receives GABAergic inhibitory projections from the globus pallidus external and strong excitatory glutamatergic afferents from the motor cortex.…”

Pituitary Iron and Volume Imaging in Healthy Controls

“…6,12 There is currently little literature reporting normative data for R2. 7,22 Additionally, we aimed to supplement current pituitary volume literature [14][15][16] by deriving sex-appropriate z-score calculations for pediatric and adult controls.…”