Pituitary iron measurement using MRI-R2 in patients with transfusional iron overload Type: Scientific Exhibit (original) (raw)
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Student's Corner Utility of MRI in assessment of pituitary iron overload
Beta thalassemia is highly prevalent in Pakistan with a carrier rate of 5-8% .The main complication of beta thalassemia major is iron overload, especially in reticuloendothelial system, heart, joints and endocrine glands. Pituitary siderosis leads to hypogonadotropic hypogonadism and growth hormone deficiency. Measures of plasma ferritin levels and hepatic iron level are used for assessing body iron overload but these are limited for various reasons particularly in case of pituitary siderosis. Magnetic Resonance Imaging (MRI) is a reliable, non invasive and easily available utility for assessing tissue siderosis. We assessed a 20 year old female beta thalassemic diagnosed with hypogonadotropic hypogonadism and pituitary siderosis using routine spin echo (SE) T1 and T2 weighted sequences of MRI and special Gradient Recalled Echo (GRE) sequence of MRI. We found MRI signal intensity to be decreased on all three sequences but most so on GRE suggesting its greatest sensitivity to pituitary iron deposition. MRI signal hypo-intensity due to paramagnetic effects of iron has been validated for liver siderosis but is still under investigation for pituitary siderosis. Our findings suggest that MRI especially GRE sequence can be used in conjunction with laboratory data to evaluate pituitary siderosis and to prevent further pituitary dysfunction.
AJNR. American journal of neuroradiology
To identify the optimal MR imaging technique for diagnosing pituitary iron overload, we compared spin-echo and gradient-echo MR imaging with measurements of pituitary T2 relaxation times in 30 patients with secondary hemochromatosis due to transfusion-dependent beta-thalassemia major and in 10 healthy volunteers. We found that the optimal MR imaging technique to evaluate pituitary iron overload is the gradient-echo T2*-weighted technique, as it best demonstrated signal reduction in the anterior lobe of the pituitary gland.
Predicting pituitary iron and endocrine dysfunction
Annals of The New York Academy of Sciences, 2010
Patients with thalassemia major (TM) require lifelong transfusion therapy to survive, leading to toxic iron overload in the endocrine glands and heart. The pituitary gland is one of the most vulnerable targets, leading to irreversible hypogonadotropic hypogonadism in approximately half of patients. Improvements in magnetic resonance imaging (MRI) technology and understanding have allowed earlier recognition of preclinical iron deposition in the heart, pancreas, and liver; prior work also supports a similar role for the pituitary. The purpose of this study is threefold, (1) to develop age-specific nomograms for pituitary iron and volume metrics; (2) to determine the prevalence, severity, and age of onset of pituitary iron deposition and volume loss in TM patients, and (3) to determine whether deferasirox monotherapy can modify the trajectory of pituitary iron accumulation and damage over a two-year period. This article outlines relevant background studies and methodological details as well as providing preliminary results from our first two aims.
European Journal of Radiology, 2007
Hypogonadism, resulting from iron-induced pituitary dysfunction, is the most frequently reported complication in patients with -thalassaemia major. The aim of this study was to evaluate pituitary Magnetic Resonance Imaging (MRI) signal intensity reduction, on T2*-weighted images, as a marker of pituitary iron overload. Thirty patients (13 females and 17 males, mean age: 16.6 ± 4.1) with -thalassaemia major on conventional treatment and 13 healthy volunteers (7 females and 6 males, mean age: 11 ± 4.51 years) were studied with T2*-weighted images of the anterior pituitary using a 1.5 T unit. Four thalassaemic patients (2 females and 2 males) had clinical hypogonadism and required hormonal replacement treatment. Results revealed a statistically significant reduction of pituitary signal intensity in the thalassaemia group compared to controls (p < 0.001). Moreover, hypogonadal patients had significantly decreased MRI values compared to thalassaemic patients without hypogonadism (p = 0.017). Relatively decreased adeno-hypophyseal MRI signal intensity was recorded in pubertal thalassaemic patients. A significant negative correlation was observed between pituitary MRI values and age (r = −0.67, r 2 = 0.443, p = 0.001), whereas ferritin levels and pituitary MRI values were moderately correlated (r = −0.56, r 2 = 0.32, p = 0.08) in adult thalassaemic patients. In conclusion, pituitary MRI indices as measured on T2*-weighted images seem to reflect pituitary iron overload and could, therefore, be used for a preclinical detection of patients who are in greater danger of developing hypogonadism.
International Journal of Applied Pharmaceutics
Objective: The purpose of this study is to see the correlation between iron overload with the hypogonadal state by analyzing the correlation between ferritin serum, transferrin saturation and pituitary MRI T2 relaxation time with FSH, LH and testosterone levels. Methods: This is a cross-sectional study of 32 male subjects with transfusion-dependent thalassemia. The subjects were collected with a consecutive sampling technique in the thalassemia outpatient clinic in National Hospital in Indonesia. Measurements of serum ferritin, transferrin saturation, FSH, LH and testosterone were taken using ELISA technique. Pituitary MRI T2 relaxation time was done using MRI Avanto 1.5 Tesla. Results: In this study, secondary sexual characteristics were not fully achieved in 62.5% of patients. Low testosterone levels were found in 25% of patients. There was a negative correlation between transferrin saturation and pituitary MRI T2 relaxation time in the normal testosterone level group. Conclusion:...
Journal of Advances in Medicine and Medical Research, 2021
Background: Thalassemia is a common genetic disorder associated with endocrine disorders. Iron deposition may start in the anterior pituitary gland, but clinical signs are usually not evident until puberty. Aim of the study was to evaluate pituitary iron overload in children with β thalassemia using MRI T2* and correlate MRI T2* and biochemical markers of iron overload with pituitary hormones. Patients and Methods: This study was carried out on 30 children with β-thalassemia major (19 females and 11 males ) with their age ranging from 10 - 18 years and mean age value of 12.8 ± 2.4 and 30 healthy children of matched age and sex as controls in the period from September 2018 to September 2019. For all patients the following were done: complete clinical evaluation including anthropometric data and Tanner staging, laboratory investigations including serum iron status, thyroid function, basal and growth hormone provocation test by clonidine, Follicle stimulating hormone (FSH) , Luteinizin...
Clinical neuroradiology, 2021
Purpose Anterior pituitary iron overload and volume shrinkage is common in patients with transfusion-dependent anemia and associated with growth retardation and hypogonadotropic hypogonadism. We investigated the accuracy of different MRI-based pituitary volumetric approaches and the relationship between pituitary volume and MRI-R2, particularly with respect to growth and hypogonadism. Methods In 43 patients with transfusion-dependent anemia (12-38 years) and 32 healthy controls (12-72 years), anterior pituitary volume was measured by a sagittal T1 GRE 3D sequence at 1.5T and analyzed by 3D semi-automated threshold volumetry (3D-volumetry). This reference method was compared with planimetric 2D-volumetry, approximate volume calculations, and pituitary height. Using a multiple SE sequence, pituitary iron as MRI-R2 was assessed by fitting proton signal intensities to echo times. Growth and hypogonadism were obtained from height percentile tables and patients' medical charts. From body surface area and age adjusted anterior pituitary volumes of controls, Z-scores were calculated for all subjects. Separation of controls and patients with respect to Z and pituitary R2 was performed by bivariate linear discriminant analysis. Results Tuned 2D volumes showed highest agreement with reference 3D-volumes (bias-4.8%; 95% CI:-8.8%|-0.7%). A linear discriminant equation of Z =-17.8 + 1.45 • R2 revealed optimum threshold sensitivity and specificity of 65% and 100% for discrimination of patients from controls, respectively. Of correctly classified patients 71% and 75% showed hypogonadism and growth retardation, respectively. Conclusion Accurate assessment of anterior pituitary size requires 3D or precise 2D volumetry, with shorter analysis time for the latter. Anterior pituitary volume Z-scores and R2 allow for the identification of patients at risk of pituitary dysfunction.
International Journal of Applied Pharmaceutics, 2020
Objective: The purpose of this study is to see the correlation between iron overload with the hypogonadal state by analyzing the correlation between ferritin serum, transferrin saturation and pituitary MRI T2 relaxation time with FSH, LH and testosterone levels. Methods: This is a cross-sectional study of 32 male subjects with transfusion-dependent thalassemia. The subjects were collected with a consecutive sampling technique in the thalassemia outpatient clinic in National Hospital in Indonesia. Measurements of serum ferritin, transferrin saturation, FSH, LH and testosterone were taken using ELISA technique. Pituitary MRI T2 relaxation time was done using MRI Avanto 1.5 Tesla. Results: In this study, secondary sexual characteristics were not fully achieved in 62.5% of patients. Low testosterone levels were found in 25% of patients. There was a negative correlation between transferrin saturation and pituitary MRI T2 relaxation time in the normal testosterone level group. Conclusion: This study showed a high rate of patients who had not achieve puberty, but a low rate of patients with low testosterone, which means there is a weak negative correlation between transferrin saturation and pituitary MRI T2 relaxation times.
American Journal of Neuroradiology, 2014
BACKGROUND AND PURPOSE: Patients with -thalassemia require blood transfusion to prolong their survival, which could cause iron overload in multiple organs, including the heart, liver, and brain. In this study, we aimed to quantify iron loading in the brains of patients with -thalassemia major through the use of MR quantitative susceptibility imaging. MATERIALS AND METHODS: Thirty-one patients with thalassemia with a mean (Ϯ standard deviation) age of 25.3 (Ϯ5.9) years and 33 age-matched healthy volunteers were recruited and underwent MR imaging at 3T. Quantitative susceptibility images were reconstructed from a 3D gradient-echo sequence. Susceptibility values were measured in the caudate nucleus, putamen, globus pallidus, red nucleus, substantia nigra, dentate nucleus, and choroid plexus. General linear model analyses were performed to compare susceptibility values of different ROIs between the patients with thalassemia and healthy volunteers. RESULTS: Of the 31 patients, 27 (87.1%) had abnormal iron deposition in one of the ROIs examined. Significant positive age effect on susceptibility value was found in the putamen, dentate nucleus, substantia nigra, and red nucleus (P ϭ .002, P ϭ .017, P ϭ .044, and P ϭ .014, respectively) in the control subjects. Compared with healthy control subjects, patients with thalassemia showed significantly lower susceptibility value in the globus pallidus (P Ͻ .001) and substantia nigra (P ϭ .003) and significantly higher susceptibility value in the red nucleus (P ϭ .021) and choroid plexus (P Ͻ .001). CONCLUSIONS: A wide range of abnormal susceptibility values, indicating iron overloading or low iron content, was found in patients with thalassemia. MR susceptibility imaging is a sensitive method for quantifying iron concentration in the brain and can be used as a potentially valuable tool for brain iron assessment. ABBREVIATIONS: QSM ϭ quantitative susceptibility mapping; GP ϭ globus pallidus; DN ϭ dentate nucleus; SN ϭ substantia nigra; CP ϭ choroid plexus; DFO ϭ deferoxamine; L1 ϭ deferiprone B eta-thalassemia major is a disease caused by genetic defects that lead to reduced production of hemoglobin. The patients require blood transfusion to prolong their survival, which could cause iron overload in multiple organs, including the heart, liver,