Magnetic resonance imaging assessment of cardiac and liver iron load in transfusion dependent patients

Optimized serum ferritin prediction of iron overload in transfusion-dependent thalassemia: likelihood ratio and age-adjustment approach

BACKGROUND

Early detection of iron overload in transfusion-dependent thalassemia (TDT) patients is critical to prevent complications and improve survival.

OBJECTIVES

Evaluate the utility of serum ferritin (SF) in the prediction of hepatic and myocardial iron overload (HIO and MIO) compared to T2*-MRI.

DESIGN

Retrospective SETTINGS: Governmental hospitals.

PATIENTS AND METHODS

Patients with TDT who had T2*-MRI examinations between January 2016 to October 2019 were included. The predictive value of SF for detection of HIO and MIO was assessed by measuring area under the curve (AUC). A sample size of 123 cases was calculated to detect a correlation of 0.25 with 90% power and a two-sided type I error of 0.05.

MAIN OUTCOME MEASURES

The correlation between SF and estimated hepatic iron concentration.

SAMPLE SIZE

137 TDT patients who required regular blood transfusions.

RESULTS

The predictive value of SF was excellent for detection of HIO (AUC=0.83-0.87) but fair for detection of MIO (AUC=0.67). The two independent predictors of MIO were age and SF. The log of (age × SF) enhanced the SF predictive value for MIO (AUC=0.78). SF values of 700 and 1250 mg/L effectively excluded mild and moderate HIO with a sensitivity of 97.8% and 94.2%, respectively (LR-=0.1). While SF values of 1640 and 2150 mg/L accurately diagnosed mild and moderate HIO with a specificity of 95.55% and 96.4%, respectively (LR+>10). A log of (age × SF) cut-off value of 4.15 effectively excluded MIO (LR-=0.1), while a value of 4.65 moderately confirmed MIO (LR+=3.2).

CONCLUSIONS

SF is an excellent predictor of hepatic IO in TDT. Age adjustment enhanced its myocardial IO predictive accuracy. Likelihood ratio-based SF cut-off values may help clinicians in risk stratification and treatment decision-making.

LIMITATIONS

The laboratory data were gathered retrospectively and although the risk of selection bias for T2*-MRI examination is thought to be low, it cannot be ignored.

CONFLICT OF INTEREST

None.

Magnetic resonance imaging T2* of the pancreas value using an online software tool and correlate with T2* value of myocardium and liver among patients with transfusion-dependent thalassemia major

Objective

Patients with thalassemia major do require lifetime blood transfusions that eventually result in iron accumulation in different organs. We described the usefulness of using magnetic resonance imaging (MRI) T2^*imaging values for the evaluation of pancreatic iron load in these patients, and we correlated it with MRI T2^* haemosiderosis of the myocardium and liver that has been recognized as a non-invasive assessment of iron overload among patients with thalassemia major.

Materials and methods

We conducted a cross-sectional study on 39 patients with thalassemia major in one of the tertiary university hospitals for a 1-year period. Demographic data were collected from the patient's history. MRI T2^* of the pancreas, liver, and heart were executed on all patients in the same setting. Objective values of iron overload in these organs were obtained using the MRI post-processing software from online software.

Results

A total of 32 (82.1%) patients had pancreatic iron overload including 2 patients (5.1%) with severe iron overload and 15 patients (38.5%) with moderate and mild iron overload, respectively. Nine patients (23.1%) had myocardial iron overload, which included 3 patients (7.7%) who had severe cardiac haemosiderosis. Notably, 37 patients (94.9%) had liver iron overload, which included 15 patients (38.5%) who had severe liver haemosiderosis. There was a moderate positive correlation between the relaxation time of the pancreas and heart haemosiderosis (r = 0.504, P < 0.001). No significant correlation was found between the relaxation time of the pancreas with the liver and the heart with the liver.

Conclusion

Pancreatic haemosiderosis precedes cardiac haemosiderosis, which establishes a basis for initiating earlier iron chelation therapy to patients with thalassemia major.

Iron overload after allogeneic stem cell transplantation in children with acute lymphoblastic leukemia

Red blood cell transfusions are an essential part of supporting care in leukemia treatment. We examined the prevalence of iron overload and its effects on organ function and childhood growth in pediatric patients after allogeneic HSCT for acute lymphoblastic leukemia. Twenty-three patients were included (median age 12.6, range 7.5-21.4 years). Body iron load was determined using laboratory tests, hepatic and cardiac MRI, and by calculating iron received from transfusions. We performed multivariate analysis to determine association of body iron load with liver enzymes, cardiac function, insulin resistance, and growth. Median plasma ferritin was 344 (range 40-3235) ng/mL and exceeded 1000 ng/mL in three patients (13%). In MRI, 11 patients (48%) had hepatic iron overload and 1 patient (4%) myocardial iron overload. In cardiac MRI, 8 patients (35%) had significant but subclinical decrease in ejection fraction (median z-score -1.7, range -3.1-0.14), but cardiac function did not associate with iron status. Alanine transaminase associated with transfused iron per time unit (P = .001) after the median follow-up of 4.5 years. No correlation was found between iron load and growth or insulin resistance. Iron overload is common in children transplanted for ALL, but iron overload associated organ dysfunction is not present at early age. We recommend evaluation of iron load for all patients at least once during follow-up after transplantation.

Evaluation of Liver Iron Content by Magnetic Resonance Imaging in Children with Acute Lymphoblastic Leukemia after Cessation of Treatment

Objective

There are a limited number of studies evaluating iron overload in childhood leukemia by magnetic resonance imaging (MRI). The aim of this study was to determine liver iron content (LIC) by MRI in children with acute lymphoblastic leukemia (ALL) who had completed treatment and to compare those values with serum iron parameters.

Materials and Methods

A total of 30 patients between the ages of 7 and 18 who had completed ALL treatment were included in the study. Serum iron parameters (serum iron, serum ferritin [SF], and total iron-binding capacity) and liver function tests were studied. R2 MRI was performed for determining LIC.

Results

Normal LIC was detected in 22 (63.4%) of the cases. Seven (23.3%) had mild and 1 (3.3%) had moderate liver iron deposition. In contrast, severe iron overload was not detected in any of the cases. LIC levels were correlated with the numbers of packed red blood cell (pRBC) transfusions (r=0.637, p<0.001), pRBC transfusion volume (r=0.449, p<0.013), SF levels (r=0.561, p=0.001), and transferrin saturation (r=0.353, p=0.044). In addition, a positive correlation was found between the number of pRBC transfusions and SF levels (r=0.595, p<0.001).

Conclusion

We showed that the frequency of liver iron deposition was low and clinically less significant after the end of treatment in childhood ALL patients. LIC was demonstrated to be related to SF and transfusion history. These findings support that SF and transfusion history may be used as references for monitoring iron accumulation or identifying cases for further examinations such as MRI.

MRI evaluation of hepatic and cardiac iron burden in pediatric thalassemia major patients: spectrum of findings by T2*

Background

Iron deposition distorts the local magnetic field exerting T2* signal decay. Biopsy, serum ferritin, echocardiography are not reliable to adjust iron chelation therapy. Quantified MRI signal decay can replace biopsy to diagnose iron burden, guide treatment, and follow up. The objective of this study is to evaluate the role of T2* in quantification of the liver and heart iron burden in thalassemia major patients. This cross-sectional study included 44 thalassemia patients who were referred to MRI unit, underwent T2* MRI.

Results

Twenty-one male (47.7%) and 23 female (52.3%) were included (age range 6–15 years, mean age 10.9 ± 2.9 years). Patients with excess hepatic iron show the following: 11/40 (27.5%) mild, (13/40) 32.5% moderate, and (14/40) 35% severe liver iron overload. High statistical significance regarding association between LIC and liver T2* (p = 0.000) encountered. Cardiac T2* values showed no relationship with age (p = 0.6).

Conclusion

T2* is a good method to quantify, monitor hepatic and myocardial iron burden, guiding chelation therapy and prevent iron-induced cardiac complications.

N-terminal-pro-b-type natriuretic peptide levels and cardiac hemosiderosis in adolescent β-thalassemia major patients

Background:

Iron-induced cardiomyopathy remains the leading cause of mortality in patients with β-thalassemia major. Iron overload cardiomyopathy, which may be reversible through iron chelation, is characterized by early diastolic dysfunction. Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is a sensitive biomarker of diastolic dysfunction.

Aim:

The aim of the study is to evaluate the diagnostic value of NT-proBNP as a surrogate marker of iron overload examined with magnetic resonance imaging T2-star (MRI T2*).

Methods:

Sixty-eight β-thalassemia major patients (10–18 years) with no signs of heart failure underwent NT-proBNP measurement before routine transfusion. All participants prospectively underwent cardiac MRI T2* examination within 3 months (median 19 days). Patients were divided as cardiac hemosiderosis (cardiac MRI T2* <20 ms) and nonhemosiderosis (cardiac MRI T2* >20 ms).

Results:

Of 68 patients, the male-to-female ratio was 1:1.1 and the median age was 14.1 years (range: 10–17.8 years). NT-proBNP levels were not different between hemosiderosis and nonhemosiderosis patients (P = 0.233). Further receiver operating characteristic analysis resulted in no significant correlation of NT-proBNP and MRI T2* (area under the curve 0.393, P = 0.233).

Conclusion:

Measurement of NT-proBNP levels cannot be used for early detection of cardiac iron overload in adolescent with β-thalassemia major.

Evaluation of cardiac and hepatic iron overload in thalassemia major patients with T2* magnetic resonance imaging

OBJECTIVES

Recent advancements have promoted the use of T2* magnetic resonance imaging (MRI) in the non-invasive detection of iron overload in various organs for thalassemia major patients. This study aims to determine the iron load in the heart and liver of patients with thalassemia major using T2* MRI and to evaluate its correlation with serum ferritin level and iron chelation therapy.

METHODS

This cross-sectional study included 162 subjects diagnosed with thalassemia major, who were classified into acceptable, mild, moderate, or severe cardiac and hepatic iron overload following their T2* MRI results, respectively, and these were correlated to their serum ferritin levels and iron chelation therapy.

RESULTS

The study found that 85.2% of the subjects had normal cardiac iron stores. In contrast, 70.4% of the subjects had severe liver iron overload. A significant but weak correlation (r = -0.28) was found between cardiac T2* MRI and serum ferritin, and a slightly more significant correlation (r = 0.37) was found between liver iron concentration (LIC) and serum ferritin.

DISCUSSION

The findings of this study are consistent with several other studies, which show that patients generally manifest with liver iron overload prior to cardiac iron overload. Moreover, iron accumulation demonstrated by T2* MRI results also show a significant correlation to serum ferritin levels.

CONCLUSION

This is the first study of its kind conducted in Indonesia, which supports the fact that T2* MRI is undoubtedly valuable in the early detection of cardiac and hepatic iron overload in thalassemia major patients.

Serum Ferritin Levels Correlation With Heart and Liver MRI and LIC in Patients With Transfusion-Dependent Thalassemia

BACKGROUND

Iron-loaded cardiac complication is the essential cause of mortality in patients with thalassemia. Early detection and treatment of cardiac over-load can reduce mortality.

OBJECTIVES

The current study aimed to evaluate the relationship between serum ferritin levels and T2* magnetic resonance imaging (MRI) of heart and liver and liver iron concentration (LIC) to diagnose iron over load in countries with limited access.

PATIENTS AND METHODS

In the current cross-sectional study, 85 Iranian patients with thalassemia with the mean age of 22.7 ± 7 years were randomly selected. All patients were on regular blood transfusion. Echocardiography of heart and liver T2* MRI, determination of serum ferritin levels, and LIC were performed in all subjects at the same time. The correlation of serum ferritin levels with T2*MRI of heart and liver, and LIC was assessed. P value < 0.05 was considered statistically significant.

RESULTS

Abnormal myocardial iron load (T2* MRI < 20 ms) was detected in 58% of the patients and among whom, 36% had severe myocardial iron load (T2* MRI < 10 ms). Median and interquartile range of serum ferritin levels were 1434 and 2702 respectively in patients with thalassemia. Serum ferritin levels showed a statistically significant positive correlation with LIC (rs = 0.718, P < 0.001) and significant negative correlation with T2* Heart (rs = -0.329, P = 0.002), and T2* Liver (rs = -0.698, P < 0.001). However, Ejection fraction was not significantly correlated with serum ferritin levels in the patients (P = 0.399).

CONCLUSIONS

Serum ferritin levels can be used to diagnose iron over-load in patients with thalassemiaas an alternative method in areas where T2* MRI is not available.

How early can myocardial iron overload occur in beta thalassemia major?

BACKGROUND

Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM.

METHODS AND RESULTS

We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload.

CONCLUSIONS

The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old.

Iron overload in children undergoing cancer treatments

BACKGROUND

Iron overload is responsible for severe morbidity and mortality in polytransfused patients. Although repeated blood transfusions are needed during the treatment of most cancers, pediatric patients are not routinely screened for subsequent iron overload.

PROCEDURE

Seventy-five patients were identified as candidates for cancer treatment and enrolled prospectively in a yearly protocol including a cardiac and liver magnetic resonance imaging coupled with ferritin level measurements. Patients were divided into four groups using the intensity of treatment rating (ITR-3).

RESULTS

Fifty-nine patients reached 1-year of follow-up and liver iron overload was found in up to 66% of them. Such overload correlated with the total volume of red blood cells transfused and persisted at least 2 years after the initiation of therapy. Moderate myocardial overload was also, but less frequently (14%), observed in these patients.

CONCLUSIONS

Our study demonstrated that severe liver iron overload as well as moderate myocardial iron overload can be found 1 year after cancer treatment and that this overload persists overtime. The patients with higher ITR and those who have received more than a liter of blood red cells per square meter, regardless of their diagnosis or ITR, are at risk of iron overload and should be screened carefully.

A practical approach for a wide range of liver iron quantitation using a magnetic resonance imaging technique

The goal of this study is to demonstrate a practical magnetic resonance imaging technique for quantifying a wide range of hepatic iron concentration (HIC) for hematologic oncology patients with transfusion iron overload in a routine clinical setting. To cover a wide range of T₂* values from hematologic patients, we used a dual-acquisition method with two clinically available acquisition protocols on a 1.5T MRI scanner with different ΔTEs to acquire data in two breath-holds. An in-house image postprocessing software tool was developed to generate T₂*, iron maps, and water and fat images, when fat is presented in the liver. The resulting iron maps in DICOM format are transferred to the institutional electronic medical record system for review by radiologists. The measured liver T₂* values for 28 patients ranged from 0.56 ± 0.13 to 25.0 ± 2.1 milliseconds. These T₂* values corresponded to HIC values ranging from 1.2 ± 0.1 mg/g to 45.0 ± 10.0 mg/g (dry weight). A moderate correlation between overall serum ferritin levels and R₂* was found with a correlation coefficient of 0.83. Repeated phantom scans confirmed that the precision of this method is better than 4% for T₂* measurements. The dual- acquisition method also improved the ability to quantify HIC of the patients with hepatic steatosis.

Chronically transfused pediatric sickle cell patients are protected from cardiac iron overload

Iron overload is a major toxicity of chronic transfusions. Myocardial iron overload is associated with cardiac dysfunction. Cardiac and liver magnetic resonance imaging (MRI) was performed on 14 chronically transfused sickle cell disease (SCD) and non-sickle cell disease (non-SCD) patients seen at Vanderbilt Children's Hospital from 1 January 2000 to 10 March 2010. Retrospective review was conducted to assess cardiac T2*, liver T2*, ventricular dimensions and function, echocardiogram, length of transfusion, hemoglobin, and ferritin measurements. Ten patients had SCD and 4 had non-SCD, including α-thalassemia, β-thalassemia, and Diamond-Blackfan anemia. Cardiac T2* was normal in all SCD patients (mean 39 ± 12 ms), but abnormal in 3 of 4 non-SCD patients (mean 11.8 ± 2.4 ms). Liver T2* was similar between SCD (mean 6.2 ± 1.6 ms) and non-SCD patients (mean 5.9 ± 1.9 ms), and did not correlate with serum ferritin. Comparing SCD and non-SCD patients with similar transfusion duration, SCD patients had normal cardiac T2* and non-SCD patients had abnormal cardiac T2*. No patients had cardiomyopathy, but ventricular dilatation was common among SCD patients. Chronically transfused pediatric SCD patients are relatively spared of myocardial iron overload, which is unlikely to be due to lower total body iron burden in SCD patients than non-SCD patients.

The relationship between cardiac and liver iron evaluated by MR imaging in haematological malignancies and chronic liver disease

Although iron overload is clinically significant, only limited data have been published on iron overload in haematological diseases. We investigated cardiac and liver iron accumulation by magnetic resonance imaging (MRI) in a cohort of 87 subjects who did not receive chelation, including 59 haematological patients. M-HIC (MRI-based hepatic iron concentration, normal values <36 μmol/g) is a non-invasive, liver biopsy-calibrated method to analyse iron concentration. This method, calibrated to R2 (transverse relaxation rate), was used as a reference standard (M-HIC(R2)). Transfusions and ferritin were evaluated. Mean M-HIC(R2) and cardiac R^* of all patients were 142 μmol/g (95% CI, 114–170) and 36.4 1/s (95% CI, 34.2–38.5), respectively. M-HIC(R2) was higher in haematological patients than in patients with chronic liver disease or normal controls (P<0.001). Clearly elevated cardiac R2^* was found in two myelodysplastic syndrome (MDS) patients with severe liver iron overload. A poor correlation was found between liver and cardiac iron (n=82, r=0.322, P=0.003), in contrast to a stronger correlation in MDS (n=7, r=0.905, P=0.005). In addition to transfusions, MDS seemed to be an independent factor in iron accumulation. In conclusion, the risk for cardiac iron overload in haematological diseases other than MDS is very low, despite the frequently found liver iron overload.

Noninvasive measurement of liver iron concentration at MRI in children with acute leukemia: initial results

BACKGROUND

Routine assessment of body iron load in patients with acute leukemia is usually done by serum ferritin (SF) assay; however, its sensitivity is impaired by different conditions including inflammation and malignancy.

OBJECTIVE

To estimate, using MRI, the extent of liver iron overload in children with acute leukemia and receiving blood transfusions, and to examine the association between the degree of hepatic iron overload and clinical parameters including SF and the transfusion iron load (TIL).

MATERIAL AND METHODS

A total of 25 MRI measurements of the liver were performed in 15 children with acute leukemia (mean age 9.75 years) using gradient-echo sequences. Signal intensity ratios between the liver and the vertebral muscle (L/M ratio) were calculated and compared with SF-levels. TIL was estimated from the cumulative blood volume received, assuming an amount of 200 mg iron per transfused red blood cell unit.

RESULTS

Statistical analysis revealed good correlation between the L/M SI ratio and TIL (r = -0.67, P = 0.002, 95% confidence interval CI = -0.83 to -0.34) in patients with acute leukemia as well as between L/M SI ratio and SF (r = -0.76, P = 0.0003, 95% CI = -0.89 to -0.52).

CONCLUSION

SF may reliably reflect liver iron stores as a routine marker in patients suffering from acute leukemia.

Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

PURPOSE

To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement.

MATERIALS AND METHODS

Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated.

RESULTS

For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was substantially preserved in the two groups identified considering the T2* normal cutoff. All segmental T2* values were correlated with the single ROI T2* value. After the application of a correction map based on T2* fluctuations in the healthy subjects, no significant differences were found in the segmental T2* values.

CONCLUSION

Hepatic T2* variations are low and due to artifacts and measurement variability. The single ROI approach can be adopted in the clinical arena, taking care to avoid the susceptibility artifacts, occurring mainly in segments VII and VIII.

Polystyrene microsphere-ferritin conjugates: a robust phantom for correlation of relaxivity and size distribution

In vivo iron load must be monitored to prevent complications from iron overload diseases such as hemochromatosis or transfusion-dependent anemias. While liver biopsy is the gold standard for determining in vivo iron load, MRI offers a noninvasive approach. MR phantoms have been reported that estimate iron concentration in the liver and mimic relaxation characteristics of in vivo deposits of hemosiderin. None of these phantoms take into account the size distribution of hemosiderin, which varies from patient to patient based on iron load. We synthesized stable and reproducible microsphere-ferritin conjugates (ferribeads) of different sizes that are easily characterized for several parameters that are necessary for modeling such as iron content and bead fraction. T(1) s and T(2) s were measured on a 1.41-T low-resolution NMR spectrometer and followed a size-dependent trend. Ferribeads imaged at 4.7 and 14.1 T showed that signal intensities are dependent on the distribution of ferritin around the bead rather than the iron concentration alone. These particles can be used to study the effects of particle size, ferritin distribution, and bead fraction on proton relaxation and may be of use in mimicking hemosiderin in a phantom for estimating iron concentration.

Gradient-echo magnetic resonance imaging study of pancreatic iron overload in young Egyptian beta-thalassemia major patients and effect of splenectomy

BACKGROUND

Thalassemic patients suffer from diabetes mellitus secondary to hemosiderosis.

AIMS

The study aimed to evaluate pancreatic iron overload by T2*-weighted Gradient-echo magnetic resonance imaging (MRI) in young beta-thalassemia major patients and to correlate it with glucose disturbances, hepatic hemosiderosis, serum ferritin and splenectomy.

METHODS

Forty thalassemic patients (20 non diabetic, 10 diabetic, and 10 with impaired glucose tolerance) were recruited from Pediatric Hematology Clinic, in addition to 20 healthy controls. All patients underwent clinical assessment and laboratory investigations included complete blood count, liver function tests, serum ferritin and oral glucose tolerance test (OGTT). A T2*-weighted gradient-echo sequence MRI was performed with 1.5 T scanner and signal intensity ratio (SIR) of the liver and the pancreas to noise were calculated.

RESULTS

Significant reduction in signal intensity ratio (SIR) of the liver and the pancreas was shown in thalassemic patients compared to controls (P < 0.0001), Thalassemic patients with abnormal glucose tolerance; including diabetics and thalassemics with impaired glucose tolerance; displayed a higher degree of pancreatic and hepatic siderosis compared to thalassemics with normal glucose tolerance or controls (P < 0.001, P < 0.0001). Splenectomized thalassemic patients had significantly lower SIR of pancreas compared to non splenectomized patients (P < 0.05). A strong correlation was present between hepatic and pancreatic siderosis in studied patients (P < 0.001).

CONCLUSIONS

pancreatic siderosis can be detected by T2* gradient-echo MRI since childhood in thalassemic patients, and is more evident in patients with abnormal glucose tolerance. After splenectomy, iron deposition may be accelerated in the pancreas. Follow up of thalassemic patients using pancreatic MRI together with intensive chelation therapy may help to prevent the development of overt diabetes.

Liver iron content determination by magnetic resonance imaging

Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients with hemochromatosis or transfusion-dependent anemia, therefore, liver iron concentration (LIC) accurately reflects total body iron stores. In the past 20 years, magnetic resonance imaging (MRI) has emerged as a promising method for measuring LIC in a variety of diseases. We review the potential role of MRI in LIC determination in the most important disorders that are characterized by iron overload, that is, thalassemia major, other hemoglobinopathies, acquired anemia, and hemochromatosis. Most studies have been performed in thalassemia major and MRI is currently a widely accepted method for guiding chelation treatment in these patients. However, the lack of correlation between liver and cardiac iron stores suggests that both organs should be evaluated with MRI, since cardiac disease is the leading cause of death in this population. It is also unclear which MRI method is the most accurate since there are no large studies that have directly compared the different available techniques. The role of MRI in the era of genetic diagnosis of hemochromatosis is also debated, whereas data on the accuracy of the method in other hematological and liver diseases are rather limited. However, MRI is a fast, non-invasive and relatively accurate diagnostic tool for assessing LIC, and its use is expected to increase as the role of iron in the pathogenesis of liver disease becomes clearer.