Magnetic resonance imaging signal reduction may precede volume loss in the pituitary gland of transfusion-dependent beta-thalassemic patients

Hekmatnia, Ali; Radmard, Amir Reza; Rahmani, Ali; Adibi, Atoosa; Khademi, Hooman

doi:10.3109/02841850903292743

Cited by 22 publications

(18 citation statements)

References 17 publications

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“…Our results are consistent with their findings. Most recently, Hekmatnia et al [51] estimated the pituitary gland volume 479 ± 127.74 mm 3 using mathematical formulas. In our study, however, we found that the pituitary gland volume was 432.82 ± 147.38 mm 3 using elliptic formula.…”

Section: Discussionmentioning

confidence: 99%

Comparison of three methods for the estimation of the pituitary gland volume using magnetic resonance imaging: a stereological study

et al. 2010

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Stereological techniques using point counting and planimetry have been used to estimate pituitary gland volume. However, many studies have estimated pituitary gland volume by the mathematical approach the elliptic formula. The objective of the current study was to determine pituitary gland volume using stereological methods and elliptic formula on magnetic resonance imaging (MRI). In this study, pituitary gland volumes were estimated in a total of 28 subjects (22 females, 6 males,) who were free of any pituitary or neurological symptoms and signs. The mean ± SD pituitary gland volumes for the point counting, planimetry and elliptic formulae groups were 582.14 ± 140.16 mm³, 610.08 ± 133.17 mm³, and 432.82 ± 147.38 mm³, respectively. The mean CE for the pituitary gland volume estimates derived from the point counting technique was 8.07%. No significant difference was found between point counting and planimetric methods for the pituitary gland volume (P > 0.05). In addition, there was a 26.14 and 29.71% underestimation of pituitary volume as measured by the elliptic formula compared to the point counting and planimetric techniques, respectively. From these results, it can be concluded that stereological techniques are unbiased, efficient and reliable methods and are ideally suitable for in vivo examination of MRI data for pituitary gland volume estimation. Hence, we suggest that estimating pituitary gland volume using MRI study and stereology may be clinically relevant for pituitary surgeons for the investigation of the structure and function of the pituitary gland.

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Section: Discussionmentioning

confidence: 99%

Comparison of three methods for the estimation of the pituitary gland volume using magnetic resonance imaging: a stereological study

et al. 2010

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“…[161718192021] In addition, protein kinase C has been shown to be regulated by iron with possible deleterious effect of excess iron on its function. [212223] Both mechanisms appear to be affected by iron overload and can explain the defective TSH secretion in response to low FT4 in thalassemic patients. The deposition of iron in the pituitary gland and its deleterious effects on pituitary size and functions has been reported in many studies.…”

Section: Discussionmentioning

confidence: 99%

Longitudinal study on thyroid function in patients with thalassemia major: High incidence of central hypothyroidism by 18 years

Soliman

Yafei

Al-Naimi

et al. 2013

Indian J Endocr Metab

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Introduction:Primary hypothyroidism is one of the most frequent complications observed in-patients suffering from thalassemia. We investigated and reviewed the thyroid function in all thalassemic patients attending the Pediatric Endocrine Clinic of Hamad Medical Center, Doha, Qatar during the last 10 years of follow-up.Patients and Methods:A total of 48 patients with ί-thalassemia major between 5 years and 18 years of age. Thyroid dysfunction was defined as follows: Overt hypothyroidism (low Free thyroxine [FT4] and increased thyroid-stimulating hormone [TSH] levels >5 μIU/ml); subclinical hypothyroidism (normal FT4, TSH between 5 μIU/ml and 10 μIU/ml) and central (secondary) hypothyroidism (low FT4 and normal or decreased TSH).Results:A total of 48 patients (22 males and 26 females) completed a 12 year-period of follow-up. During this period, hypothyroidism was diagnosed in 17/48 (35%) of patients. There was no significant difference in the prevalence in males 7/22 (32%) versus females 10/26 (38%). Sixteen of the patients had hypothyroidism after the age of 10 years (94%). The prevalence of overt hypothyroidism had risen from 0% at the age of 7 years to 35% at the age of 18 years. None of the patients had high anti-thyroperoxidase antibody titers. Out of 17 patients, 13 patients with hypothyroidism had normal or low TSH level (not appropriately elevated) indicative of defective hypothalamic pituitary response to low FT4 (central hypothyroidism). Three patients (6.3%) had subclinical hypothyroidism (TSH between 5 uIU/ml and 10 uIU/ml and normal FT4). The general trend of FT4 level showed progressive decrease over the 12 years, whereas, TSH levels did not show a corresponding increase. These data suggested defective hypothalamic pituitary thyroid axis involving both TSH and FT4 sretion in patients with thalassemia major over time. There was a significant negative correlation between serum ferritin and FT4 (r = −0.39, P = 0.007), but no correlation was found between ferritin and TSH.Conclusions:Worsening of thyroid function was observed in 35% of the studied thalassemic patients by the age of 18 years. The lack of proper increase of TSH in response to the low circulating levels of FT4 in 13/17 (76%) of these patients indicates a relatively high incidence of defective pituitary thyrotrophic function in these patients.

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

Section: Discussionmentioning

confidence: 99%

“…6,7,11 There has also been evidence that increased R2 precedes pituitary volume loss and hypogonadism. 12 We have demonstrated that R2 deposition can be seen in children as young as 4 years of age, with volume loss beginning in the second decade of life. 13 These findings suggest that proper MR imaging screening may identify iron-mediated HH before it is clinically observable in at-risk patients.…”

mentioning

confidence: 99%

Pituitary Iron and Volume Imaging in Healthy Controls

Noetzli¹,

Panigrahy²,

Hyderi³

et al. 2011

AJNR Am J Neuroradiol

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Magnetic resonance imaging signal reduction may precede volume loss in the pituitary gland of transfusion-dependent beta-thalassemic patients

Cited by 22 publications

References 17 publications

Comparison of three methods for the estimation of the pituitary gland volume using magnetic resonance imaging: a stereological study

Comparison of three methods for the estimation of the pituitary gland volume using magnetic resonance imaging: a stereological study

Longitudinal study on thyroid function in patients with thalassemia major: High incidence of central hypothyroidism by 18 years

Pituitary Iron and Volume Imaging in Healthy Controls

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