The pancreas in beta-thalassemia major: MR imaging features and correlation with iron stores and glucose disturbances

Evaluation of iron overload in visceral organs in thalassemia patients by point shear-wave elastography

INTRODUCTION

The aim of this study was to investigate the value of point shear-wave elastography (pSWE) in the measurement of iron overload in the liver and other visceral organs in patients with beta thalassemia major (BTM).

MATERIALS AND METHODS

The study included 103 patients diagnosed with BTM who were referred to our clinic for cardiac and liver T2* measurement and a control group of 120 age- and gender-matched healthy volunteers. Cardiac and hepatic T2* measurements were performed in the patient group. Hepatic, pancreatic, splenic, and renal pSWE values were measured in both groups. The pSWE values were compared between the two groups. In the patient group, correlations between pSWE values, cardiac-hepatic T2* values and hepatic size, patient age, and serum ferritin levels were analyzed.

RESULTS

Hepatic, pancreatic, splenic, and renal pSWE values were significantly higher in the patient group compared to the control group (p ≤ 0.001, < 0.001, 0.014, 0.026, respectively). In the patient group, hepatic pSWE values established a significant correlation with cardiac T2* values, liver size-T2*, pancreatic pSWE values, serum ferritin levels, and age (p = 0.006, < 0.001, 0.001, 0.042, 0.001, 0.032, respectively). In the ROC analysis, the area under the ROC curve was 0.807 for hepatic pSWE in the discrimination of thalassemia patients and healthy controls, and the cut-off value was 1.42, which gave a sensitivity and specificity of 75.7% and 75%, respectively. CONCLUSıON: Point shear-wave elastography can be a useful technique in the clinical measurement of iron overload in the liver, pancreas, spleen, and kidney.

Pancreatic fatty replacement as risk marker for altered glucose metabolism and cardiac iron and complications in thalassemia major

OBJECTIVES

This multicenter study assessed the extent of pancreatic fatty replacement and its correlation with demographics, iron overload, glucose metabolism, and cardiac complications in a cohort of well-treated patients with thalassemia major (TM).

METHODS

We considered 308 TM patients (median age: 39.79 years; 182 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Magnetic resonance imaging was used to quantify iron overload (IO) and pancreatic fat fraction (FF) by T2* technique, cardiac function by cine images, and to detect replacement myocardial fibrosis by late gadolinium enhancement technique. The glucose metabolism was assessed by the oral glucose tolerance test.

RESULTS

Pancreatic FF was associated with age, body mass index, and history of hepatitis C virus infection. Patients with normal glucose metabolism showed a significantly lower pancreatic FF than patients with impaired fasting glucose (p = 0.030), impaired glucose tolerance (p < 0.0001), and diabetes (p < 0.0001). A normal pancreatic FF (< 6.6%) showed a negative predictive value of 100% for abnormal glucose metabolism. A pancreatic FF > 15.33% predicted the presence of abnormal glucose metabolism. Pancreas FF was inversely correlated with global pancreas and heart T2* values. A normal pancreatic FF showed a negative predictive value of 100% for cardiac iron. Pancreatic FF was significantly higher in patients with myocardial fibrosis (p = 0.002). All patients with cardiac complications had fatty replacement, and they showed a significantly higher pancreatic FF than complications-free patients (p = 0.002).

CONCLUSION

Pancreatic FF is a risk marker not only for alterations of glucose metabolism, but also for cardiac iron and complications, further supporting the close link between pancreatic and cardiac disease.

KEY POINTS

• In thalassemia major, pancreatic fatty replacement by MRI is a frequent clinical entity, predicted by a pancreas T2* < 20.81 ms and associated with a higher risk of alterations in glucose metabolism. • In thalassemia major, pancreatic fatty replacement is a strong risk marker for cardiac iron, replacement fibrosis, and complications, highlighting a deep connection between pancreatic and cardiac impairment.

Serum Ferritin Levels and Other Associated Parameters with Diabetes Mellitus in Adult Patients Suffering from Beta Thalassemia Major

Background

Although beta thalassemia major (BTM) patients are properly treated with blood transfusions in accompany with iron chelation therapy, they suffer from complications, such as diabetes mellitus (DM).

Purpose

The purpose was to detect the critical serum ferritin level and other parameters correlated with DM among adult BTM patients. Also, it was to study whether each of these parameters is associated with a certain period of age.

Patients and Methods

This study included 200 adult BTM patients. A cross-sectional study was carried out. Patients clinical and laboratory variables, such as ferritin levels, and fasting blood glucose (FBS) were extracted from medical records at Zagazig University Hospital, Egypt. Liver and cardiac iron contents were assessed using MRI T2* methods. Statistical analysis was performed using IBM SPSS V26.0 software package.

Results

The overall frequency of DM over the total sample equals 6.5%. There were no impaired fasting glucose (IFG) in the medical records. Statistical significance between serum ferritin and DM was (P = 0.014). The serum ferritin 2500 ng/mL with age group (27-<32) years-old were risk factors. The distributions of DM according to BMI were (3.5%) of class overweight. Significant association between DM and BMI was (r = 0.357, P < 0.001). Liver MRI T2* has significant correlation with serum ferritin, but cardiac MRI T2* was poorly correlated. Association between liver and cardiac MRI T2* was not found.

Conclusion

Age group (27-<32) years-old and ferritin >2500 ng/mL should be properly treated immediately. The serum ferritin and BMI of class "overweight" were risk factors for DM. Factors such as diet should be followed. Serum ferritin can be used for estimating liver iron content for economic factors. But cardiac MRI T2* must be performed for evaluating cardiac iron accurately.

Cardiac iron overload evaluation in thalassaemic patients using T2* magnetic resonance imaging following chelation therapy: a multicentre cross-sectional study

INTRODUCTION

Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia.

METHODS

We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011.

RESULTS

We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation.

CONCLUSIONS

Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.

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.

Pancreatic iron quantification with MR imaging: a practical guide

Accurate determination of pancreatic iron status is crucial for preventing impairment of the exocrine and endocrine function of the pancreas and for prospectively stratifying the cardiac iron risk. The following article should be a sort of practical guide for radiologists interested in quantifying pancreatic iron overload by Magnetic Resonance Imaging (MRI). After a brief background on iron-deposition diseases, we will describe basic principles and relative advantages and disadvantages of the more widely used and clinically feasible MRI-based techniques for pancreatic iron assessment. These methods can be classified into signal intensity ratio (SIR) and relaxometry methods. We will examine different technical aspects representing the key for accurate and precise relaxation time measurement.

Metabolic implications of pancreatic fat accumulation

Fat accumulation outside subcutaneous adipose tissue often has unfavourable effects on systemic metabolism. In addition to non-alcoholic fatty liver disease, which has received considerable attention, pancreatic fat has become an important area of research throughout the past 10 years. While a number of diagnostic approaches are available to quantify pancreatic fat, multi-echo Dixon MRI is currently the most developed method. Initial studies have shown associations between pancreatic fat and the metabolic syndrome, impaired glucose metabolism and type 2 diabetes mellitus. Pancreatic fat is linked to reduced insulin secretion, at least under specific circumstances such as prediabetes, low BMI and increased genetic risk of type 2 diabetes mellitus. This Review summarizes the possible causes and metabolic consequences of pancreatic fat accumulation. In addition, potential therapeutic approaches for addressing pancreatic fat accumulation are discussed.

Fatty Pancreas: An Underappreciated Intersection of the Metabolic Profile and Pancreatic Adenocarcinoma

Although the prevalence of pancreatic cancer is increasing, treatment strategies remain limited, and success is rare. A growing body of evidence links pancreatic cancer to pre-existing metabolic disorders, including, but not limited to, type 2 diabetes mellitus and obesity. An infrequently described finding, fatty pancreas, initially described in the context of obesity in the early 20th century, appears to be at the crossroads of type 2 diabetes and obesity on the one hand, and the development of pancreatic cancer on the other. Similarly, other conditions of the pancreas, such as intrapancreatic mucinous neoplasms, also seem to be related to diabetes while increasing the subsequent risk of pancreatic cancer. In this review, the author explores the diagnostic criteria for, and prevalence of, fatty pancreas and the potential link to other pancreatic conditions, including pancreatic cancer. Diagnostic limitations, and areas of controversy are also addressed, as are potential therapeutic approaches to fatty pancreas intended to reduce the subsequent risk of pancreatic cancer.

Economic burden in the management of transfusion-dependent thalassaemia patients in Malaysia from a societal perspective

BACKGROUND

Transfusion-dependent thalassaemia (TDT) is a hereditary blood disorder in which blood transfusion is the mainstay treatment to prolong survival and improve quality of life. Patients with this disease require blood transfusion at more than 100 ml/kg annually and iron-chelating therapy (ICT) to prevent iron overload (IOL) complications. There are substantial numbers of TDT patients in Malaysia, but limited data are available regarding the economic burden associated with this disease. The purpose of this study was to determine the lifetime cost of TDT from a societal perspective and identify potential factors increasing patient and family expenditures among thalassaemia populations.

METHODS

The total lifetime cost per TDT patient (TC1) is the sum of lifetime healthcare cost (TC2) and lifetime patient and family healthcare expenditure (TC3). TC2 was simulated using the Markov model, taking into account all costs subsidized by the government, and TC3 was estimated through a cross-sectional health survey approach. A survey was performed using a two-stage sampling method in 13 thalassaemia centres covering all regions in Malaysia.

RESULTS

A TDT patient is expected to incur TC2 of USD 561,208. ICT was the main driver of cost and accounted for 56.9% of the total cost followed by blood transfusion cost at 13.1%. TC3 was estimated to be USD 45,458. Therefore, the estimated TC1 of a TDT patient was USD 606,665. Sensitivity analyses showed that if all patients were prescribed oral ICT deferasirox for their lifetime, the total healthcare cost would increase by approximately 65%. Frequency of visits to health facilities for blood transfusion/routine monitoring and patients who were prescribed desferrioxamine were observed to be factors affecting patient and family monthly expenses.

CONCLUSION

The lifetime cost per TDT patient was USD 606,665, and this result may be useful for national health allocation planning. An estimation of the economic burden will provide additional information to decision makers on implementing prevention interventions to reduce the number of new births and medical service reimbursement.

Quantification of pancreatic iron overload and fat infiltration and their correlation with glucose disturbance in pediatric thalassemia major patients

Background

Diabetes mellitus affects more than a quarter of patients with thalassemia major (TM) worldwide, and increases the risk for cardiac complications, contributing to significant morbidity. Pancreatic iron overload (IO) and fat infiltration have been correlated with this endocrinal complication in adult TM patients. It has been shown that in adult TM patients, iron accumulation and fat infiltration are found to be heterogeneous in the pancreatic head, body, and tail region. R2* and a fat fraction (FF) generated by gradient-echo imaging can be used as quantitative parameters to assess the iron and fat contents of the pancreas. This study aimed to determine the pattern of pancreatic iron accumulation and fat infiltration in pediatric TM patients with gradient-echo imaging and evaluate the association between pancreatic IO and fat infiltration and glucose disturbances.

Methods

A total of 90 children with TM (10.7±3.1 years) were included. All patients underwent pancreatic magnetic resonance imaging (MRI) using multi-echo gradient-echo sequences. IO was measured by R2* relaxometry in 90 patients, and FF values were measured using iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method in 40 patients. R2* and FF were assessed in the pancreatic head, body, and tail. The global R2* and global FF values were obtained by averaging the respective values from the pancreatic head, body, and tail. The correlations between global R2*, global FF, and fasting glucose were determined using Spearman's correlation analysis. The Friedman test was used to compare R2* and FF among different pancreatic regions. Receiver operating characteristic (ROC) analysis was used to determine the performance of global R2* and global FF in discriminating impaired fasting glucose from normal fasting glucose patients.

Results

The global R2* was positively correlated with the global FF in the pancreas (r=0.895, P<0.001). No significant differences were found in R2* among the 3 regions of the pancreas (χ²=4.050, P=0.132), but significant differences were found in FF among the 3 pancreatic regions (χ²=16.350, P<0.001). Both global pancreatic R2* (r=0.408, P<0.001) and global FF (r=0.523, P=0.001) were positively correlated with fasting glucose. ROC analysis showed that global pancreatic R2* and global FF had an area under the curve of 0.769 and 0.931 (both P<0.001), respectively, in discriminating between impaired and normal glucose function patients.

Conclusions

Pediatric TM patients can have homogeneous iron siderosis and heterogeneous fat infiltration in the pancreas as measured by gradient-echo imaging, both of which are risk factors for diabetes.

Value of liver iron concentration in healthy volunteers assessed by MRI

Iron overload is a relatively common clinical condition resulting from disorders such as hereditary hemochromatosis, thalassemia, sickle cell disease, and myelodysplasia that can lead to progressive fibrosis and eventually cirrhosis of the liver. Therefore, it is essential to recognize the disease process at the earliest stage. Liver biopsy is the reference test for the assessment of liver fibrosis. It also allows for quantifying liver iron concentration (LIC) in patients. However, this is an invasive method with significant limitations and possible risks. Magnetic resonance imaging (MRI) and evaluation of the R2* relaxation rate can be an alternative to biopsy for assessing LIC. However, it causes a need for accurate R2* data corresponding to standard value for further comparison with examined patients. This study aimed to assess the normative values of liver R2* in healthy individuals. A total of 100 volunteers that met established criteria were enrolled in the study: 36 (36%) men and 64 (64%) women. The mean age was 22.9 years (range 20 to 32 years). R2* was estimated by an MRI exam with a 1.5 T clinical magnetic resonance scanner. Images for measuring the LIC and liver fat concentration were obtained using the IDEAL-IQ technique for liver imaging. The Mean (SD) liver R2* was 28.34 (2.25) s⁻¹ (95% CI, 27.78–28.90, range 23.67–33.00 s⁻¹) in females, 29.57 (3.20) s⁻¹ (95% CI, 28.49–30.66, range 23.93–37.77 s⁻¹) in males, and 28.72 (2.69) s⁻¹ (range 23.67–37.77 s⁻¹) in the whole group. R2* value in this particular population with a high proportion of young women did not exceed 38 s⁻¹. In the absence of fibrosis or steatosis, liver stiffness and fat fraction did not show any relationship with R2*.

Impact of MRI technique on clinical decision-making in patients with liver iron overload: comparison of FerriScan- versus R2*-derived liver iron concentration

OBJECTIVES

The purpose of this study was to compare clinical decision-making in iron overload patients using FerriScan and an R2*-based approach.

METHODS

One-hundred and six patients were imaged at two consecutive timepoints (454 ± 158 days) on a 1.5-T Siemens MAGNETOM Avanto Fit scanner. For both timepoints, patients underwent the standard FerriScan MRI protocol. During the second exam, each patient additionally underwent R2*-MRI mapping. For each patient, a retrospective (simulated) decision was made to increase, decrease, or maintain chelator levels. Two different decision models were considered: The fixed threshold model assumed that chelator adjustments are based strictly on fixed liver iron concentration (LIC) thresholds. Decisions made with this model depend only on the most recent LIC value and do not require any clinician input. The second model utilized decisions made by two hematologists retrospectively based on trends between two consecutive LIC values. Agreement (κ_A) between hematologists (i.e., interobserver variability) was compared with the agreement (κ_B) between a single hematologist using the two different LIC techniques.

RESULTS

Good agreement between R2*- and FerriScan-derived decisions was achieved for the fixed threshold model. True positive/negative rates were greater than 80%, and false positive/negative rates were less than 10%. ROC analysis yielded areas under the curve greater than 0.95. In the second model, the agreement in clinical decision-making for the two scenarios (κ_A vs. κ_B) was equal at the 95% confidence level.

CONCLUSIONS

Switching to R2*-based LIC estimation from FerriScan has the same level of agreement in patient management decisions as does switching from one hematologist to another.

KEY POINTS

• Good agreement between R2*- and FerriScan-derived decisions in liver iron overload patient management • Switching to R2*-based LIC estimation from FerriScan has the same level of agreement in patient management decisions as does switching from one hematologist to another.

Glucose dysregulation in patients with iron overload: is there a relationship with quantitative pancreas and liver iron and fat content measured by MRI?

OBJECTIVES

The aim was to investigate the relationship between pancreatic and hepatic iron and fat to glucose metabolism in patients with iron overload and address conflicting results in literature as regards the relationship between pancreas iron and glucose dysregulation.

METHODS

We retrospectively evaluated pancreatic and hepatic R2*, fat fraction (FF), liver iron concentration (LIC), and glucose metabolism in 105 patients with iron overload obtained with a multi-echo gradient echo R2* technique and assessed the correlation between pancreatic R2* and FF to glucose dysregulation.

RESULTS

There were no significant differences in pancreatic R2*, liver R2*, and FF in patients with iron overload and glucose dysregulation compared to those with normoglycemia (p = 0.435, p = 0.674, and p = 0.976), whereas pancreatic FF was significantly higher, 23.5% vs 16.7% respectively (p = 0.011). Pancreatic FF and R2* demonstrated an area under the curve of 0.666 and 0.571 for discriminating glucose dysregulation. Pancreatic FF of 26.2% yielded specificity and sensitivity of 80% and 45% for prediction of glucose dysregulation. Pancreatic R2* weakly correlated with pancreatic FF, r = 0.388 (p < 0.001), and liver R2*, r = 0.201 (p = 0.033), and showed no correlation with hepatic FF r = -0.013 (p = 0.892) or LIC categories (p = 0.493).

CONCLUSION

Pancreatic FF but not pancreatic R2* was associated with glucose dysregulation in patients with iron overload. Prior studies reporting correlation of pancreatic R2* to glucose dysregulation likely relate from inadequate MRI technique or analysis employed, which unlike our study did not perform simultaneous measurements of fat and iron essential to avoid their confounding effects during quantitative analysis.

KEY POINTS

• Pancreatic fat fraction, unlike iron, is associated with glucose dysregulation in iron overload. • Simultaneous measurement of pancreatic iron and fat content with MRI is essential to avoid confounding effects of one another during quantitative analysis. • Pancreatic fat fraction could be utilized to predict glucose dysregulation in iron overload states.

Endocrine Complications

More than five decades ago, thalassemia major (TM) was fatal in the first decade of life [...]

Hypogonadism in male thalassemia major patients: pathophysiology, diagnosis and treatment

Failure of pubertal growth, delay or absence of sexual development, infertility and sexual dysfunction due to hypogonadism and defective spermatogenesis are frequent and well recognized disturbances among male patients with transfusion dependent (TD) thalassaemia major (β-thal). These problems are attributed mainly to the damage caused by chronic anaemia and the deposition of excess iron in the pituitary gland and testicles. This is a short review of male pubertal disorders in patients with β-thal written by pediatric endocrinologists and haematologists with an interest and active involvement, in the diagnosis and management of these complications in this group of patients. A vigilant clinical evaluation of growth and puberty, as well as an appropriate hormonal evaluation in poly-transfused (TD β-thal) patients is strongly recommended for early detection and treatment of endocrine dysfunction. Of crucial importance also, is the implementation of an efficient chelation regime from early life, to prevent severe iron load and permanent damage to the endocrine glands, particularly those responsible for gonadal function.

Tissue iron quantification in chronic liver diseases using MRI shows a relationship between iron accumulation in liver, spleen, and bone marrow

AIM

To investigate iron loading within the liver, pancreas, spleen, and bone marrow using magnetic resonance imaging (MRI) transverse relaxation rate (R2*), in patients with diffuse liver diseases; to evaluate the relationships between iron accumulation in these tissue compartments; and to assess the association between tissue iron overload and the pattern of hepatic cellular iron distribution (hepatocytes versus Kupffer cells).

MATERIAL AND METHODS

Fifty-six patients with diffuse liver diseases had MRI-derived R2* values, using a multi-echo chemical-shift encoded MRI sequence, of the liver, pancreas, spleen, and vertebral bone marrow. All patients had liver biopsy samples scored for hepatic iron grading (0-4) and iron cellular distribution (within hepatocytes only or within both hepatocytes and Kupffer cells).

RESULTS

Liver R2* increased with histological iron grade (R_S=0.58, p<0.001) and correlated with spleen (R_S=0.71, p<0.001) and bone marrow R2* (R_S=0.66, p<0.001), but not with pancreatic R2* (R_S=0.22, p=0.096). Splenic and bone marrow R2* values were also correlated (R_S=0.72, p<0.001). Patients with iron inside Kupffer cells had the highest R2* in liver, spleen and bone marrow.

CONCLUSIONS

Patients with chronic diffuse liver diseases have concomitant hepatic, splenic, and bone marrow iron loading. The highest hepatic iron scores and iron inside Kupffer cells were associated with the highest splenic and bone marrow deposits, suggesting systemic iron accumulation in the mononuclear phagocytic system.

Correlation of Pancreatic Iron Overload Measured by T2*-Weighted Magnetic Resonance Imaging in Diabetic Patients with β-Thalassemia Major

Diabetes mellitus (DM) is one of the potential complications in patients with transfusion-dependent β-thalassemia major (β-TM). In this case-controlled study, we examined the pancreatic iron levels in outpatients with β-TM. In this study, cases of patients with β-TM and DM were gender- and age-matched with control subjects, who were non-diabetic and had normal blood glucose on standard oral glucose tolerance (OGTT) tests. One of four diagnoses [normal, pre-diabetes, impaired glucose tolerance (IGT), DM] was made according to the American Diabetes Association (ADA) criteria. The T2*-weighted magnetic resonance imaging (T2*-weighted MRI) of the heart, liver, and pancreas was performed using a 1.5 Tesla scanner. The study enrolled 26 diabetic cases, 17 non-diabetic cases, and eight cases of IGT or pre-diabetes cases. The severity of pancreatic and cardiac iron siderosis was significantly different between the groups. We found a statistically significant difference at 5.6 ms in the T2*-weighted MRI values for the pancreas between patients with normal vs. abnormal glucose metabolism [p < 0.009; odds ratio (OR): 11.2; 95% confidence interval (95% CI): 1.32-94.4)]. The receiver operating characteristic (ROC) curve for the 5.6 ms cutoff led to an area under the curve (AUC) of 0.69 (95% CI: 55.0-84.0; p < 0.02), with sensitivity and specificity of 94.0 and 42.0%, respectively. There was a moderate positive correlation between pancreatic and cardiac T2*-weighted MRI (r = 0.4; p < 0.001), and a weak correlation between the pancreas and the liver (r = 0.38; p < 0.005). To conclude, we have introduced a cutoff of 5.6 ms on T2*-weighted MRI of the pancreas for prediction of abnormal glucose metabolism in β-TM patients.

T2* Magnetic Resonance Imaging Study of Pancreatic Iron Overload and its Relation With the Diabetic State in Thalassemic Patients

The present study was performed to evaluate pancreatic hemosiderosis by means of magnetic resonance imaging (MRI) T2* and its relation to the diabetic state in thalassemic patients. One hundred thirty transfusion-dependent thalassemic patients from Zafar adult thalassemia clinic, Tehran, Iran, were enrolled in the study. Data such as age, type of thalassemia, age at diagnosis, transfusion duration, ferritin level, and fasting blood sugar results were gathered. Pancreatic MRI T2* was performed for all patients. One hundred four thalassemic patients with no sign of diabetes mellitus and 26 thalassemic patients with diabetes mellitus entered the study. Out of a total of 130 patients, 102 had pancreatic hemosiderosis. Among them, 23 of 26 diabetic patients (88.5%) and 79 of 104 nondiabetic patients (76%) showed pancreatic hemosiderosis, indicating no statistically significant difference between the 2 groups. The mean pancreatic MRI T2* relaxation time for all patients was 13.99±12.43 ms. The mean relaxation was 13.62±8.38 and 14.08±13.28 ms for diabetic and nondiabetic patients, respectively, showing no statistical difference (P=0.202). In conclusion, we did not find a significant difference between diabetic and nondiabetic thalassemic patients regarding the MRI T2* relaxation time readings or the rate of pancreatic hemosiderosis. We recommend performing studies with a higher sample size and including patients from different age groups to further evaluate the role of T2* MRI of pancreatic iron overload and its relation with the diabetic state in thalassemic patients.

R2*-relaxometry of the pancreas in patients with human hemochromatosis protein associated hereditary hemochromatosis

PURPOSE

To evaluate pancreatic iron in patients with human hemochromatosis protein associated hereditary hemochromatosis (HHC) using R2* relaxometry.

MATERIALS AND METHODS

81 patients (58 male, 23 female; median age 49.5, range 10-81 years) with HHC were retrospectively studied. All underwent 1.5T magnetic resonance imaging (MRI) of the abdomen. A fat-saturated multi-gradient echo sequence with 12 echoes (TR=200ms; TE-initial 0.99ms; Delta-TE 1.41ms; 12 echoes; flip-angle: 20°) was used for the R2* quantification of the liver and the pancreas. Parameter maps were analyzed using regions of interest (3 in the liver and 2 in the pancreas) and R2* values were correlated.

RESULTS

59/81 patients had a liver R2*≥70 1/s of which 10/59 patients had a pancreas R2*≥50 1/s. No patient presented with a liver R2*<70 1/s and pancreas R2*≥50 1/s. All patients with pancreas R2* values≥50 1/s had liver R2* values≥70 1/s. ROC analysis resulted in a threshold of 209.4 1/s for liver R2* values to identify HFE positive patients with pancreas R2* values≥50 1/s with a median specificity of 78.87% and a median sensitivity of 90%.

CONCLUSION

In patients with HHC R2* relaxometry of the pancreas should be performed when liver iron overload is present and can be omitted in cases with no sign of hepatic iron.

Evaluation of Iron Deposition in the Adrenal Glands of β Thalassemia Major Patients Using 3-Tesla MRI

Background

Beta-thalassemia major (β-TM) patients need blood transfusions, which result in iron deposition. To regulate chelation therapy, iron load has to be measured. With MRI, the amount of signal loss and T2* decay time shortening are used for iron quantification.

Objectives

The aim was to measure adrenal iron load with T2* relaxometry using MRI, and to compare it with liver and cardiac iron and serum ferritin, and to find out whether adrenal iron could be predicted from those parameters.

Patients and Methods

Between October 2014 and March 2015, MRI was performed in 21 patients with β-TM, recieving blood transfusions and chelation therapy. The control group (n = 11) included healthy volunteers with no known history of adrenal, hematologic, chronic disease, and blood transfusion.

Results

Among patients, there was no significant correlation between plasma ferritin and adrenal T2*. Significant difference was detected among T2* values of adrenals between the patient and control groups. There was no significant correlation between adrenal gland and liver T2* in β-TM patients, moderate correlation was detected between adrenal T2* and cardiac T2*.

Conclusion

Adrenal iron in β-TM can be reliably measured in 3 Tesla MRI. The results highlight the absence of correlation between adrenal iron deposition both with serum ferritin and hepatic iron.

The ICET-A Recommendations for the Diagnosis and Management of Disturbances of Glucose Homeostasis in Thalassemia Major Patients

Iron overload in patients with thalassemia major (TM) affects glucose regulation and is mediated by several mechanisms. The pathogenesis of glycaemic abnormalities in TM is complex and multifactorial. It has been predominantly attributed to a combination of reduced insulin secretory capacity and insulin resistance. The exact mechanisms responsible for progression from norm glycaemia to overt diabetes in these patients are still poorly understood but are attributed mainly to insulin deficiency resulting from the toxic effects of iron deposited in the pancreas and insulin resistance. A group of endocrinologists, haematologists and paediatricians, members of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A) convened to formulate recommendations for the diagnosis and management of abnormalities of glucose homeostasis in thalassemia major patients on the basis of available evidence from clinical and laboratory data and consensus practice. The results of their work and discussions are described in this article.

Exploring the metabolic syndrome: Nonalcoholic fatty pancreas disease

After the first description of fatty pancreas in 1933, the effects of pancreatic steatosis have been poorly investigated, compared with that of the liver. However, the interest of research is increasing. Fat accumulation, associated with obesity and the metabolic syndrome (MetS), has been defined as “fatty infiltration” or “nonalcoholic fatty pancreas disease” (NAFPD). The term “fatty replacement” describes a distinct phenomenon characterized by death of acinar cells and replacement by adipose tissue. Risk factors for developing NAFPD include obesity, increasing age, male sex, hypertension, dyslipidemia, alcohol and hyperferritinemia. Increasing evidence support the role of pancreatic fat in the development of type 2 diabetes mellitus, MetS, atherosclerosis, severe acute pancreatitis and even pancreatic cancer. Evidence exists that fatty pancreas could be used as the initial indicator of “ectopic fat deposition”, which is a key element of nonalcoholic fatty liver disease and/or MetS. Moreover, in patients with fatty pancreas, pancreaticoduodenectomy is associated with an increased risk of intraoperative blood loss and post-operative pancreatic fistula.

Iron overload detection using pituitary and hepatic MRI in thalassemic patients having short stature and hypogonadism

OBJECTIVE

to assess the growth and pubertal development among a group of patients with β-Thalassemia Major (β-TM) and to evaluate the role of the pituitary gland and liver MRI signal intensity (SI) reduction in assessing and predicting the clinical severity of growth and pubertal dysfunctions.

METHODS

Thirty-eight patients with β-TM were examined and divided into two groups: Group I patients were of normal height and puberty and Group II patients had short statures and hypogonadism. Laboratory investigations included serum ferritin, LH, FSH, prolactin, TSH, and basal and dynamic growth hormones. Pituitary and liver MRIs were performed to assess the pituitary to fat (P/F) and liver to muscle (L/M) signal intensities (SI), respectively. Fifteen healthy and sex- and age-matched subjects were included as controls.

RESULTS

Both patient groups had significantly elevated serum ferritin and significantly decreased prolactin and IGF1 compared to control subjects. Group II showed a significant reduction in LH, FSH, and IGF1 and a significant increase in ferritin in comparison with Group I and the control group, and it had a highly significant reduction in both P/F and L/M SI in comparison with Group I (p<0.001 and 0.008, respectively). The reduced P/F ratio was significantly correlated with FSH and LH, and a cutoff for a P/F ratio ≥0.94 was obtained to differentiate between Group I and II.

CONCLUSION

MRI in conjunction with the P/F signal intensity ratio is a useful and noninvasive tool for the early diagnosis of pituitary iron overload.

Pancreatic iron and fat assessment by MRI-R2* in patients with iron overload diseases

BACKGROUND

To determine the pancreatic iron (R2*) and fat content (FC) in comparison to hepatic and cardiac R2* in patients with iron overload disorders like β-thalassemia major (TM), Diamond-Blackfan anemia (DBA) or hereditary hemochromatosis.

METHODS

R2* rates were assessed in the liver, heart and pancreas of 42 patients with TM, 29 subjects with other iron overload diseases, and 10 controls using an ECG-gated breathhold sequence (12 echo time [TE] = 1.3-25.7 ms, readout repetition time [TR] = 244 ms). Pancreatic R2* and FC were assessed from TE dependent region of interest based signal intensities performing water-fat chemical shift relaxometry and were compared with laboratory parameters (glucose, HbA1c, amylase and lipase).

RESULTS

A pancreatic iron gradient from tail (R2* = 122 s(-1) ) to head (R2* = 114 s(-1) , P < 10(-4) ) was found. The close association between cardiac and pancreatic R2* was also confirmed in patients with TM and other iron overload diseases (rs  = 0.64, P < 10(-4) ). Receiver operator characteristic analysis (area: 0.89, P < 10(-4) ) identified patients with elevated cardiac iron at a pancreatic R2* cut-off level of 131s(-1) (sensitivity = specificity at 81%). Highest pancreatic R2* (211s(-1) ) and FC (36%) were found in the tail region of diabetic patients with TM.

CONCLUSION

Pancreatic tail showed highest R2* rates and fat contents, especially in patients with thalassemia. Besides iron accumulation fatty degeneration might be an additional risk factor for the development of diabetes in β-thalassemia major, but this hypothesis needs further studies in prediabetic patients.

Diabetes mellitus in patients with thalassemia major

BACKGROUND

Diabetes mellitus is a major endocrinopathy for patients with thalassemia major. Although diabetes mellitus is multifactorial, iron loading is its primary cause and its management poses a clinical challenge. Detecting the pre-diabetes stage is critical because clinical diabetes can potentially be reversed or prevented.

PROCEDURE

Patients with thalassemia major who received regular blood transfusion therapy from 1994 to 2010 were evaluated for the incidence of diabetes mellitus and glucose dysregulation. The association between patients' clinical, biochemical, and image parameters was also evaluated.

RESULTS

The patients with diabetes were significantly older, had higher ferritin levels, a smaller pancreas volume, and lower cardiac T2* magnetic resonance imaging (MRI) values than the patients without diabetes. The pancreas T2* MRI values were higher in the patients without diabetes, but the difference was not statistically significant. The liver iron concentration did not differ between the patients with and without diabetes. The prevalence of hepatitis C infection and hypogonadism was also higher in the patients with diabetes. In the patients without diabetes, the cardiac T2* MRI values were higher in patients with normal fasting glucose levels (P = 0.03), and the homeostasis model assessment of insulin resistance level was associated with hepatitis C infection (P = 0.024, r = 0.32) and hypogonadism (P = 0.034, r = 0.301).

CONCLUSIONS

Fasting glucose and insulin levels were appropriate screening tools for evaluating glucose dysregulation and complemented the MRI findings. The cardiac T2* and pancreas volumes were significant predictors of diabetes.

Assessment of hepatic and pancreatic iron overload in pediatric Beta-thalassemic major patients by t2* weighted gradient echo magnetic resonance imaging

Background. MRI has emerged for the noninvasive assessment of iron overload in various tissues. The aim of this paper is to evaluate hepatic and pancreatic iron overload by T2^∗ weighted gradient echo MRI in young beta-thalassemia major patients and to correlate it with glucose disturbance and postsplenectomy status. Subjects and Methods. 50 thalassemic patients, in addition to 15 healthy controls. All patients underwent clinical assessment and laboratory investigations. Out of 50 thalassemic patients, 37 patients were splenectomized. MRI was performed for all subjects. Results. All patients showed significant reduction in the signal intensity of the liver and the pancreas on T2^∗GRD compared to controls, thalassemic patients who had abnormal glucose tolerance; diabetic and impaired glucose tolerance patients displayed a higher degree of pancreatic and hepatic siderosis and more T2^∗ drop in their signal intensity than those with normal blood sugar level. Splenectomized thalassemic patients had significantly lower signal intensity of the liver and pancreas compared to nonsplenectomized patients. Conclusion. T2^∗ gradient echo MRI is noninvasive highly sensitive method in assessing hepatic and pancreatic iron overload in thalassemic patients, more evident in patients with abnormal glucose tolerance, and is accelerated in thalassemic splenectomized patients.

Treating thalassemia major-related iron overload: the role of deferiprone

Over the last 20 years, management for thalassemia major has improved to the point where we predict that patients’ life expectancy will approach that of the normal population. These outcomes result from safer blood transfusions, the availability of three iron chelators, new imaging techniques that allow specific organ assessment of the degree of iron overload, and improvement in the treatment of hepatitis. In October 2011, the Food and Drug Administration licensed deferiprone, further increasing the available choices for iron chelation in the US. The ability to prescribe any of the three chelators as well as their combinations has led to more effective reduction of total body iron. The ability to determine the amount of iron in the liver and heart by magnetic resonance imaging allows the prescription of the most appropriate chelation regime for patients and to reconsider what our aims with respect to total body iron should be. Recent evidence from Europe has shown that by normalizing iron stores not only are new morbidities prevented but also reversal of many complications such as cardiac failure, hypothyroidism, hypogonadism, impaired glucose tolerance, and type 2 diabetes can occur, improving survival and patients’ quality of life. The most effective way to achieve normal iron stores seems to be with the combination of deferoxamine and deferiprone. Furthermore, outcomes should continue to improve in the future. Starting relative intensive chelation in younger children may prevent short stature and abnormal pubertal maturation as well as other iron-related morbidities. Also, further information should become available on the use of other combinations in chelation treatment, some of which have been used only in a very limited fashion to date. All these advances in management require absolute cooperation and understanding of parents, children, and, subsequently, the patients themselves. Only with such cooperation can normal long-term survival be achieved, as adherence to treatment is now likely the primary barrier to longevity.

Use of fat suppression in R₂ relaxometry with MRI for the quantification of tissue iron overload in beta-thalassemic patients

PURPOSE

To assess the performance and results of R(2) relaxometry using a fat-suppressed (FS) multiecho sequence and compare these to conventional R(2) relaxometry in estimating tissue iron overload.

MATERIALS AND METHODS

Relaxation rate values (R(2)=1/T2) of the liver, spleen, pancreas and vertebral bone marrow (VBM) were estimated in 21 patients with β-thalassemia major, using a respiratory-triggered 16-echo Carr-Purcell-Meiboom-Gill (CPMG) spin-echo sequence before (R(2)) and after (R(2) FS) the application of chemically selective fat suppression.

RESULTS

Hepatic and splenic R(2) FS values correlated with respective R(2) values (r=0.98 and r=0.96, P<.001), whereas correlations between R(2) FS and R(2) values for pancreas and VBM were not statistically significant. Bland-Altman plots show disagreement between R(2) and R(2) FS values, particularly for pancreas and VBM. Hepatic, pancreatic and VBM R(2) FS values correlated with serum ferritin (r=0.88, P<.001; r=0.51, P<.003; and r=0.75, P<.002, respectively). Hepatic R(2) FS values correlated with splenic R(2) FS (r=0.77, P<.03), pancreatic R(2) FS (r=0.61, P<.006) and VBM R(2) FS values (r=0.70, P<.001), whereas pancreatic R(2) FS values correlated also with VMB R(2) FS values. On the contrary, among the R(2) values of the above tissues, obtained without fat suppression, only hepatic R(2) values correlated with serum ferritin, whereas no correlation was documented between hepatic and pancreatic or VBM R(2) values. The application of fat suppression did not improve breathing or flow artifacts.

CONCLUSION

Application of fat suppression in the standard CPMG sequence improved the capability of MRI in noninvasive quantification of iron, particularly in lipid-rich tissues, such as vertebral bone marrow (VBM) and pancreas.

Pancreatic iron and glucose dysregulation in thalassemia major

Pancreatic iron overload and diabetes mellitus (DM) are common in thalassemia major patients. However, the relationship between iron stores and glucose disturbances is not well defined. We used a frequently sampled oral glucose tolerance test (OGTT), coupled with mathematical modeling, and magnetic resonance imaging (MRI) to examine the impact of pancreatic, cardiac, and hepatic iron overload on glucose regulation in 59 patients with thalassemia major. According to OGTT results, 11 patients had DM, 12 had impaired glucose tolerance (IGT), 8 had isolated impaired fasting glucose (IFG), and 28 patients had normal glucose tolerance (NGT). Patients with DM had significantly impaired insulin sensitivity and insulin release. Insulin resistance was most strongly associated with markers of inflammation and somatic iron overload, while disposition index (DI) (a measure of beta cell function) was most strongly correlated with pancreas R2*. Patients with DM and IGT had significantly worse DI than those with NGT or IFG, suggesting significant beta cell toxicity. One-third of patients having elevated pancreas R2* had normal glucose regulation (preclinical iron burden), but these patients were younger and had lower hepatic iron burdens. Our study indicates that pancreatic iron is the strongest predictor of beta cell toxicity, but total body iron burden, age, and body habitus also influence glucose regulation. We also demonstrate that MRI and fasting glucose/insulin are complementary screening tools, reducing the need for oral glucose tolerance testing, and identify high-risk patients before irreversible pancreatic damage.

Pancreatic exocrine function and cardiac iron in patients with iron overload and with thalassemia

Patients with β-thalassemia major at risk of cardiac iron overload have to be identified to undergo myocardial iron measurements by magnetic resonance imaging (MRI), especially, in areas and centers with restricted access to MRI. Measurements of heart iron, liver iron, and pancreatic exocrine function were performed in 44 patients by MRI-R2* [the transverse relaxation rate R2* (= 1/T2*) characterizes the magnetic resonance decay from protons not being in phase with each other in contrast to R2 (= 1/T2)], biomagnetic liver susceptometry (LIC), and pancreatic serum amylase (PAM) and lipase (LIP), respectively. ROC analysis (area: 0.88) for detecting patients with cardiac R2* > 50 sec(-1) (T2* < 20 msec) by LIP revealed a cut-off level of 19 U/L. In conclusion, patients at risk of elevated cardiac iron levels could be identified by the exocrine pancreatic lipase and amylase function parameters.

Iron overload in Brazilian thalassemic patients

ABSTRACT Objectives: To evaluate the use of magnetic resonance imaging in patients with β-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. Methods: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. Results: The mean serum ferritin was 2,676.5 +/- 2,051.7 ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= −0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). Conclusion: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. There was no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values

Iron chelation in thalassemia: time to reconsider our comfort zones

Over the last 20 years, the management of thalassemia major has improved to the point where we predict that the patients' life expectancy will approach that of the normal population. These outcomes result from safer blood transfusions, the availability of three iron chelators, new imaging techniques that allow organ-specific assessment of the degree of iron overload and improvement in the treatment of hepatitis. The ability to prescribe any of the three chelators, as well as their combinations, has led to a more effective reduction of the total body iron. The ability to determine the amount of iron in the liver and heart by MRI has allowed the prescription of the most appropriate chelation regime for the patient and has allowed the reconsideration of 'the comfort zones'. Thus, normalizing iron stores not only prevents new morbidities but also reverses many complications, such as cardiac failure, hypothyroidism, hypogonadism, impaired glucose tolerance and Type 2 diabetes, therefore improving survival and patients' quality of life. Furthermore, outcomes should continue to improve in the future. Starting relatively intensive chelation in younger children may prevent short stature and abnormal pubertal maturation, as well as other iron-related morbidities. In addition, further information should become available on the use of other combinations in chelation treatment, some of which have only been used in a very limited fashion so far. New safe oral chelators may also become available that may offer additional ease of use. All these advances in management do require absolute cooperation and understanding on behalf of children's parents and subsequently the adult themself. Only with such cooperation can normal long-term survival be achieved as it is likely that adherence to treatment is the primary barrier to longevity.

Impact of magnetic resonance imaging on cardiac mortality in thalassemia major

PURPOSE

To evaluate whether the introduction of magnetic resonance imaging (MRI) in the management of thalassemia major (TM) patients has affected the risk of cardiac death.

MATERIALS AND METHODS

In all, 804 TM patients from two large reference units were included and the risk of dying of cardiac causes, before and after their first MRI, was assessed by a Cox proportional hazards model with time-dependent covariates.

RESULTS

Adding information from MRI reduced the risk of cardiac death from 6.0 deaths/1000 patient-years to 3.9 deaths/1000 patient-years (P = 0.22). The risk of cardiac death before having an MRI study was 82% higher compared to the risk observed after the first MRI.

CONCLUSION

MRI has become a vital component of ongoing management and seems to have a beneficial effect on cardiac mortality in TM.

Survival in a large cohort of Greek patients with transfusion-dependent beta thalassaemia and mortality ratios compared to the general population

BACKGROUND

With transfusions and chelation therapy, the prognosis for transfusion-dependent beta thalassaemia has changed from being fatal in early childhood to a chronic disorder with prolonged survival.

DESIGN AND METHODS

  In this historical prospective study, we present survival, causes of death and mortality ratios compared to the general population in 1044 Greek patients with transfusion-dependent beta thalassaemia.

RESULTS

  At the age of 50years, the overall survival was 65.0%, while the cardiac death-free survival was 77%. Birth cohort had a significant effect on survival (P<0.001) with a negative trend towards past decades. The standardised mortality ratio (standardised for sex and ages 20-40years) compared to the general population improved significantly from 28.9 in 1990-1999 to 13.5 in 2000-2008, while the standardised cardiac mortality ratio reduced from 322.9 to 106.6, respectively.

CONCLUSIONS

 Survival in thalassaemia has dramatically improved over the last twenty years but mortality remains significantly increased, compared to the general population.

The clinical significance of pancreatic steatosis

More research is now focused on pancreatic steatosis. Multiple definitions, clinical associations and synonyms for pancreatic steatosis are described in the literature and can be confusing. The integration and comparison of several studies concerning this topic is therefore challenging. In the past, pancreatic steatosis was considered an innocuous condition, a bystander of many underlying diseases (such as congenital syndromes, hemochromatosis and viral infection). However, evidence that pancreatic steatosis (strongly associated with obesity and the metabolic syndrome) has a role in type 2 diabetes mellitus, pancreatic exocrine dysfunction, acute pancreatitis, pancreatic cancer and the formation of pancreatic fistula after pancreatic surgery is emerging. This Review focuses on the different etiological factors and the clinical consequences of pancreatic steatosis.

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.

Magnetic resonance imaging diagnosis of iron overload in a leukemic patient after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Iron overload (IO) is increasingly recognized as a common cause of hepatic dysfunction in leukemic patients who have undergone allogeneic hematopoietic stem cell transplantation. Magnetic resonance imaging (MRI) is a noninvasive method of making the diagnosis.

CASE REPORT

A patient with acute lymphocytic leukemia presented with severe liver dysfunction during salvage chemotherapy for leukemia relapse after undergoing allogeneic hematopoietic stem cell transplantation. The liver dysfunction was originally attributed to graft-versus-host disease; however, findings on MRI and liver biopsy were consistent with hepatic IO.

CONCLUSIONS

As illustrated by our case, MRI can be a reliable, noninvasive modality that should be employed in the work-up of these patients.

Pancreatic iron loading predicts cardiac iron loading in thalassemia major

Diabetes mellitus and cardiomyopathy are common in chronically transfused thalassemia major patients, occurring in the second and third decades of life. We postulated that pancreatic iron deposition would precede cardiac iron loading, representing an environment favorable for extrahepatic iron deposition. To test this hypothesis, we examined pancreatic and cardiac iron in 131 thalassemia major patients over a 4-year period. Cardiac iron (R2* > 50 Hz) was detected in 37.7% of patients and pancreatic iron (R2* > 28 Hz) in 80.4% of patients. Pancreatic and cardiac R2* were correlated (r(2) = 0.52), with significant pancreatic iron occurring nearly a decade earlier than cardiac iron. A pancreatic R2* less than 100 Hz was a powerful negative predictor of cardiac iron, and pancreatic R2* more than 100 Hz had a positive predictive value of more than 60%. In serial analysis, changes in cardiac iron were correlated with changes in pancreatic iron (r(2) = 0.33, P < .001), but not liver iron (r(2) = 0.025, P = .25). As a result, pancreatic R2* measurements offer important early recognition of physiologic conditions suitable for future cardiac iron deposition and complementary information to liver and cardiac iron during chelation therapy. Staging abdominal and cardiac magnetic resonance imaging examinations could significantly reduce costs, magnet time, and need for sedation in young patients.

Assessment of iron distribution between liver, spleen, pancreas, bone marrow, and myocardium by means of R2 relaxometry with MRI in patients with beta-thalassemia major

PURPOSE

To investigate the correlation between the degree of hepatic, splenic, pancreatic, vertebral bone marrow (VBM), and myocardial siderosis, as expressed by relaxation rate (R2 = 1/T2) values, in patients with thalassemia.

MATERIALS AND METHODS

R2 relaxation rate values of liver, spleen, VBM, pancreas, and myocardium were estimated in 68 consecutive transfusion-dependent patients with beta-thalassemia major and 10 healthy controls using a respiratory triggered 16-echo Carr-Purcell-Meiboom-Gill (CPMG) spin echo sequence.

RESULTS

Hepatic R2 values were significantly increased in all 68 patients; VBM, pancreatic, and myocardial R2 values were increased in 67/68, 35/47, and 47/61 patients, whereas five patients showed decreased pancreatic R2 attributed to fatty degeneration. Of the 39 nonsplenectomized patients, splenic R2 values were decreased in 30 and normal in nine patients. Hepatic R2 values correlated with splenic (r = 0.63, P < 0.001), VBM (r = 0.52, P < 0.001), but not with myocardial and pancreatic R2 values.

CONCLUSION

Despite positive correlations between the degree of hepatic, splenic, and VBM siderosis, as expressed by respective R2 values, there was variability of iron distribution patterns in thalassemic patients. Unpredictable patterns of iron distribution may be seen, such as normal signal of the spleen in the presence of siderotic liver, resembling primary hemochromatosis. Fatty degeneration of the pancreas was not uncommon.

T2* relaxometry in liver, pancreas, and spleen in a healthy cohort of one hundred twenty-nine subjects-correlation with age, gender, and serum ferritin

OBJECTIVE

To assess T2* values of liver, pancreas, and spleen in a healthy cohort and to compare the gained values with serum ferritin levels and anthropometric data. In addition, the relationship of T2* between the 3 organs was investigated.

MATERIALS AND METHODS

One hundred twenty-nine healthy subjects (85 women, 44 men) were examined on a 1.5-T magnetic resonance whole-body unit. Age ranged from 20 to 70 years (mean age, 47.9 +/- 11.4 years). A multislice fat-saturated breath-hold 2D multiecho gradient-echo sequence was applied for T2* measurement. To assess T2* values of the liver, pancreas, and spleen, T2* maps were calculated. The correlation of organ T2* with serum ferritin and anthropometric data (age, gender, body mass index) was investigated.

RESULTS

Measurement of T2* was feasible in all volunteers. A gender-related analysis revealed significant higher hepatic and splenic T2* values for women than for men (P < 0.01). For the pancreas, these differences could not be found. A significant negative correlation was found between hepatic T2*, splenic T2*, and serum ferritin (r = -0.62 liver, r = -0.64 spleen; P < 0.0001). In contrast, no such relationship was found for pancreatic T2* (r = -0.15). For women, a statistically significant age-dependent increase was found for splenic T2* values.

CONCLUSION

Using a fast quantitative T2* magnetic resonance imaging technique, it was possible to gain insights into the iron metabolism of a healthy cohort. Gender- and age-related differences concerning T2* and serum ferritin levels were found in the liver and spleen, but not in the pancreas.

MRI evaluation of tissue iron burden in patients with beta-thalassaemia major

beta-Thalassaemia major is a hereditary haemolytic anaemia that is treated with multiple blood transfusions. A major complication of this treatment is iron overload, which leads to cell death and organ dysfunction. Chelation therapy, used for iron elimination, requires effective monitoring of the body burden of iron, for which serum ferritin levels and liver iron content measured in liver biopsies are used as markers, but are not reliable. MRI based on iron-induced T2 relaxation enhancement can be used for the evaluation of tissue siderosis. Various MR protocols using signal intensity ratio and mainstream relaxometry methods have been used, sometimes with discrepant results. Relaxometry methods using multiple echoes achieve better sampling of the time domain in which relaxation mechanisms take place and lead to more precise results. In several studies the MRI parameters of liver siderosis have failed to correlate with those of other affected organs, underlining the necessity for MRI iron evaluation in individual organs. Most studies have included children in the evaluated population, but MRI data on very young children are lacking. Wider application of relaxometry methods is indicated, with the establishment of universally accepted MRI protocols, and further studies, including young children, are needed.

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

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.