MR imaging of spleen in beta-thalassemia major.

PURPOSE: Splenomegaly and splenic siderosis are well-known findings in beta-thalassemia major. We explored the relation between splenic size, splenic and hepatic siderosis in transfusion-dependent beta-thalassemic patients, assessed by MR imaging. MATERIALS AND METHODS: Abdominal MR imaging studies of 47 consecutive thalassemic patients and 10 healthy subjects, used as controls, were retrospectively reviewed. The signal intensity ratios of spleen and liver to the right paraspinous muscle (S/M, L/M, respectively) were calculated on T1, intermediate, and T2*-weighted gradient-echo sequences, splenic volume was estimated on axial images and serum ferritin levels were recorded. RESULTS: Decreased S/M on all MR sequences was displayed in 36 patients. Six patients presented with normal S/M on all MR sequences and 5 patients displayed splenic hypointensity only on T2* sequence. No correlation between S/M and L/M was found whereas both L/M and S/M correlated with serum ferritin (P < 0.03). Splenic volume correlated to L/M (P < 0.05) but not to S/M values. CONCLUSION: In transfusion-dependent patients with beta-thalassemia, iron deposition in spleen cannot be predicted by the degree of hepatic siderosis, whereas splenomegaly relates to liver, but not splenic, iron overload. MR imaging can be a valuable tool in elucidating iron kinetics.

Deferoxamine versus combined therapy for chelating liver, spleen and bone marrow iron in beta-thalassemic patients: a quantitative magnetic resonance imaging study.

We used magnetic resonance imaging (MRI) to compare the effect of iron chelation on liver, spleen and bone marrow. We examined 21 beta-thalassemic patients undergoing deferoxamine (DFO) (9/21) or combined therapy [DFO and deferiprone (L1), 12/21] with two abdominal MRI studies using T1-w/Pd-w/T2*-wGRE and T1-wTSE sequences. Changes in serum ferritin (DF%), and liver, spleen and marrow to paraspinous muscles signal intensity ratios (SI) in T1-wTSE sequence were calculated as D%=[(2(nd)value-1(st) value)/1(st) value] x100%. Negative DF% and positive D(SI)% indicated reduction of iron. Although 17/21 (80.9%) patients demonstrated reduction in ferritin, only 8/21 (38%), 7/21 (33.3%) and 7/21 (33.3%) patients had decreased liver, spleen and marrow iron. Patients undergoing combined therapy showed significantly greater reduction (Student's t-test, p < 0.05) or less increase (t-test, p <0.05) in iron stores. Combined therapy is more effective than DFO for removing and preventing liver, spleen and bone marrow iron accumulation in beta-thalassemic patients. Magnetic resonance imaging is valuable for organ-specific monitoring of chelation therapy.

Bone marrow changes in beta-thalassemia major: quantitative MR imaging findings and correlation with iron stores.

The purpose of this study is to describe the MR imaging features of bone marrow in beta-thalassemia major and investigate their relation to ferritin, liver and spleen siderosis. Spinal bone marrow was prospectively assessed on abdominal MR studies of 40 transfused beta-thalassemic patients and 15 controls using T1-w, Pd, T2*-w Gradient Echo (GRE) and T1-w turbo Spin Echo (TSE) sequences. Signal intensity (SI) ratios of liver, spleen and bone marrow to paraspinous muscles (L/M, S/M, B/M respectively) and the respective T2 relaxation rates (1/T2) were calculated. Serum ferritin levels were recorded. Bone marrow hypointensity in at least T2*-w GRE sequence was noted in 29/40 (72.5%) patients. Eleven/40 patients exhibited normal B/M on all MR sequences. Five/40 patients had normal B/M and low L/M. B/M correlated with L/M in T1-w TSE sequence only (r = 0.471, p = 0.05). B/M correlated with S/M and mean ferritin values in all sequences (r > 0.489, p < 0.01 and r > - 0.496, p < 0.03 respectively). Marrow 1/T2 did not correlate with ferritin values or liver and spleen 1/T2. B/M in transfused beta-thalassemic patients is related to splenic siderosis and ferritin levels. Although marrow is usually hypointense, it may occasionally display normal SI coexisting with liver hypointensity, a pattern typical of primary hemochromatosis.

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

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.