Diagnostic value of pituitary MRI in differentiation of children with normal growth hormone secretion, isolated growth hormone deficiency and multiple pituitary hormone deficiency

Minimizing unnecessary brain magnetic resonance imaging in pediatric endocrinology: a retrospective cohort analysis

Background

Brain magnetic resonance imaging (MRI) is mandatory or highly recommended in many pediatric endocrinological conditions to detect causative anatomic anomalies and rule out neoplastic lesions. However, MRI can also show findings associated with the underlying clinical condition, as well as unrelated "incidentalomas". These latter findings are often abnormalities with a high incidence in the general population for which there is no clear literature regarding their management, especially in pediatric patients. The present study aimed to evaluate the number of unnecessary performed MRIs in pediatric endocrinology.

Methods

Retrospective analysis on 584 MRI scans performed in 414 patients (254 growth hormone deficiency, 41 other causes of short stature, 116 central precocious puberty).

Results

The MRI scans were completely normal in 67% of the individuals, and the prevalence of individuals who underwent more than one MRI was 18%, with no significant differences among the groups. The overall prevalence of incidentalomas was 17%. Among 170 repeated MRI scans, 147 (86%) were not required according to a dedicated protocol. Only five patients (four GHD, one Noonan) correctly repeated the MRI. All the repeated MRI scans did not reveal any progression in the findings. If we include the MRIs performed in cases of OCSS other than Noonan syndrome (n=32) and girls with CPP older than 6 years (n=89), an additional 121 MRIs could have been avoided, leading to a total number of unnecessary MRIs to 268 (46%).

Conclusions

Only a few specific neuroimaging findings in endocrinologic pediatric patients warrant further investigation, while too often repeated imaging is carried out unnecessarily. We advocate the importance of guidelines to reduce costs for both the healthcare system and patients' families, as well as to alleviate physical and psychological distress for patients and caregivers.

Extra-pituitary midline structural abnormalities associated with ectopic posterior pituitary detected on a new rapid MRI protocol (FAST1.2)

Objective

Test if the MRI FAST1.2 protocol can detect extra-pituitary midline structural brain abnormalities in patients with ectopic posterior pituitary (EPP), and highlighting their radiological-laboratory correlations.

Subjects and methods

Cross-sectional study of patients with EPP and control group. All individuals were submitted to FAST1.2, which combines the FAST1 protocol developed by our group with 3D T2DRIVE imaging.

Results

We evaluated 36 individuals with EPP and 78 as control group. Pituitary stalk (PS) was identified in 7/36 patients in EPP group by FAST1, and in 24/36 patients in FAST1.2 (p < 0.001). FAST1 failed to detect PS in one individual in the control group, while the FAST1.2 defined the PS in all individuals. In EPP group, eleven had interhypothalamic adhesion (IHA), three septo-optic dysplasia, and one cerebellar malformation. We didn't observe higher frequency of panhypopituitarism or developmental delay in patients with IHA. In control group, three had pars intermedia cysts, one hydrocephalus, and one hypothalamic hamartoma.

Conclusion

FAST1.2 allows confident recognition of midline structural abnormalities, including the pituitary stalk and IHA, thereby making MRI acquisition faster and with no need for contrast administration. IHA could be associated with defects in neuronal migration, as occur in patients with EPP, with no clinical significance.

Obesity and pituitary gland volume - a correlation study using three-dimensional magnetic resonance imaging

PURPOSE

Obesity has become a major health problem and is associated with endocrine disorders and a disturbed hypothalamic-pituitary axis. The purpose of this study was to correlate pituitary gland volume determined by routine magnetic resonance imaging with patient characteristics, in particular body mass index and obesity.

MATERIAL AND METHODS

A total of 144 'healthy' patients with normal findings in cerebral magnetic resonance imaging were retrospectively included. Pituitary gland volume was measured in postcontrast three-dimensional T1-weighted sequences. A polygonal three-dimensional region of interest covering the whole pituitary gland was assessed manually. Physical characteristics (gender, age, body height and body mass index) were correlated with pituitary gland volume. Multiple subgroup and regression analyses were performed.

RESULTS

Pituitary gland volumes were significantly larger in females than in males (p<0.001) and young individuals (<35 years) versus middle-aged patients (35-47 years) (p=0.042). Obese patients (body mass index ≥30) had significantly larger pituitary gland volumes than overweight (25<body mass index<30; p=0.011) and normal-weight (body mass index <25; p=0.005) patients. In males, pituitary gland volumes of body mass index subgroups showed significant differences (p=0.038). Obese males had larger pituitary gland volumes than overweight patients (p=0.066) and significantly larger volumes than normal-weight (p=0.023) patients. Obese females also had larger pituitary gland volumes but without statistical significance (p>0.05). Regression analysis showed that increased pituitary gland volume is associated with higher body mass index independent from gender, age and body height.

CONCLUSION

Pituitary gland volume is increased in obese individuals and a high body mass index can be seen as an independent predictor of increased pituitary gland volume. Therefore, gland enlargement might be an imaging indicator of dysfunction in the hypothalamus-pituitary axis. Besides gender and age, body mass index should be considered by radiologists when diagnosing abnormal changes in pituitary gland volume.

The Severity of Growth Hormone Deficiency Does Not Predict the Presence or Absence of Brain Magnetic Resonance Imaging Abnormalities - A Retrospective Review

BACKGROUND

The Growth Hormone Research Society recommends that all patients diagnosed with growth hormone deficiency (GHD) should undergo brain magnetic resonance imaging (MRI). This is still a point of controversy in patients with mild GHD, as the level of peak growth-hormone (GH) as a predictor of brain MRI abnormality has not yet been established. The objective of this study was to determine if peak GH level, determined by stimulation tests, can predict the presence or absence of brain MRI abnormality.

METHODS

This study was a retrospective chart review from 2008-2015. Patients were aged 2-18 years, and had growth failure and GHD as determined by stimulation test. Patients with history of brain tumour, chemotherapy and brain surgery, prior to the diagnosis of GHD, were excluded.

RESULTS

A total of 386 patients were included. GH values (mild versus severe GHD) did not predict brain MRI abnormality with any agent (clonidine: p=0.07; arginine: p=0.17; glucagon: p=0.42). Abnormal MRI was apparent in 19.2% of the patients with mild GHD and 24.8% of the patients with severe GHD (p=0.17). Severe MRI abnormality was seen in 6.1% of the patients with mild GHD and 15.0% of the patients with severe GHD (p=0.009).

CONCLUSIONS

The severity of GHD based on peak GH levels on stimulation tests did not predict the presence or absence of brain MRI abnormalities in our study population; however, severe GHD was more strongly associated with severe brain MRI abnormalities. Based on these results we recommend obtaining brain MRI in all patients with GHD.

Differences between patients with isolated GH deficiency based on findings in brain magnetic resonance imaging

INTRODUCTION

Protocol for prescribing hormone replacement therapy in isolated growth hormone (GH) deficiency includes magnetic resonance imaging of the brain. There is controversy on the frequency of structural pituitary abnormalities and on the importance of abnormal MRI findings on prognosis and response to GH replacement.

METHODS

A descriptive, retrospective study of children of both sexes aged 0-14 years, who had undergone brain MRI, diagnosed with isolated GH deficiency at a tertiary hospital in the past 14 years, aimed at reporting the frequency of abnormal MRI findings in isolated GH deficiency, and to establish whether differences exist in height diagnosis and evolution according to MRI findings. MRI findings were also compared with the findings reported in healthy children in order to establish incidence.

RESULTS

96 patients were studied, of whom 74/96 (77%) reached adult age. Abnormal MRI findings were seen in 11.5% of them (8/11 of pituitary origin). No brain or pituitary tumor was seen in any case. Patients with abnormal images had a mean age at treatment start of 8 years, a target height of -0.8SD, and a final height of 1.04SD, while patients with normal MRI findings had an age at treatment start of 10 years old, a target height of -1.44SD, and a final height of -1.75SD, with statistically significant differences.

CONCLUSIONS

Patients with abnormal MRI findings show a more favorable response to GH replacement therapy.

High Frequency of Normal Response during GH Stimulation Tests in Patients with Ectopic Posterior Pituitary Gland: A Source of False-Negative Diagnosis of Pituitary Insufficiency

AIMS

To report false-negative normal growth hormone (GH) peak response in patients with ectopic posterior pituitary gland (EPP) identified with a simplified magnetic resonance imaging (FAST1-MRI).

METHODS

We analyzed 75 EPP patients with short stature and reduced growth velocity. Sagittal-T1 imaging (thickness: 2 mm and gap: 0.2 mm) without gadolinium administration was used. A GH peak of ≥5 ng/ml after clonidine or insulin stimulation was considered normal.

RESULTS

Normal GH response was observed in 15 of 75 (20%) patients [mean (SDS) peak = 8.2 (4.1) ng/ml]. Age at diagnosis [6.5 (3.0) years vs. 7.8 (4.1) years], gender (10 males/5 females vs. 44 males/16 females), pubertal stage (14 prepubertal/1 pubertal vs. 51 prepubertal/7 pubertal), and target height [-0.4 (0.6) vs. -0.4 (0.9)] were recorded. The perinatal history did not differ between responsive and nonresponsive patients. There was a trend to more frequent multiple hormone deficiency in nonresponsive when compared with responsive patients [3/15 (20%) and 31/60 (51.7%), respectively (p = 0.055)]. Height at diagnosis was lower in nonresponsive patients (p = 0.042). No significant difference in the IGF1 levels (p = 0.598) was observed between the groups.

CONCLUSION

Normal GH values after stimulation tests do not exclude EPP-associated GH deficiency. A simplified fast acquisition sagittal-T1 MRI protocol investigation included at the initial diagnostic approach is able to prevent misdiagnosis of GH deficiency in patients with short stature.

Pituitary gland size is a useful marker in diagnosing isolated growth hormone deficiency in short children

INTRODUCTION

Diagnosis of isolated growth hormone deficiency (IGHD) can be challenging. As short stature is common in children, confirmed diagnosis is necessary prior to commencing treatment. Pituitary hypoplasia can be seen in children with IGHD. However, confirmatory studies are lacking.

AIM

To test the application of pituitary size as a marker for IGHD in a population-matched control.

PATIENT AND METHOD

Subjects with IGHD were enrolled. Patients had brain magnetic resonance imaging, and the height and width of the pituitary were measured. Pituitary volume was calculated as (height × width)3/2. A control group was recruited.

RESULTS

Sixty patients and 130 controls were enrolled. The median and age range for the patients and controls were 11 and 3-16 years and 9 and 3-17 years, respectively. Cases had a significantly lower dimensions compared to controls (p < 0.001).

CONCLUSION

Pituitary volume can be a useful marker to compliment the diagnosis of IGHD in selected patients when population-relevant normative control data are used.

Diagnostic pitfalls in the assessment of congenital hypopituitarism

BACKGROUND

The diagnosis of congenital hypopituitarism is difficult and often delayed because its symptoms are nonspecific.

AIM

To describe the different clinical presentations of children with congenital hypopituitarism to reduce the time for diagnosis and to begin a precocious and appropriate treatment.

STUDY DESIGN

We analyzed a cohort of five children with congenital hypopituitarism, describing their clinical, biochemical and radiological characteristics from the birth to diagnosis.

RESULTS

As first sign of the disease, all of five patients presented a neonatal hypoglycemia, associated in four cases with jaundice. In all these four cases, the clinicians hypothesized a metabolic disease delaying the diagnosis, which was performed in only two cases within the neonatal period. In the other three cases, the diagnosis was formulated at 2, 5 and 8 years of life because there was severe and precocious growth impairment.

CONCLUSIONS

It is important to suspect congenital hypopituitarism in the presence of persistent neonatal hypoglycemia associated with jaundice and of a precocious and severe reduction of the growth velocity in childhood. In all these cases, it is necessary to undertake a hypothalamic-pituitary magnetic resonance imaging scan as soon as possible, and to start appropriate treatment.

Pituitary stalk interruption syndrome in 59 children: the value of MRI in assessment of pituitary functions

Pituitary imaging abnormality is a specific indicator of hypopituitarism. This study involved a retrospective review of 59 children diagnosed with pituitary stalk interruption syndrome (PSIS). Of the 59 eligible patients, 54 were born by breech delivery, and there was a significant difference between numbers of patients with breech and head-presenting birth. In order to discuss the relationship between pituitary functions and delineation of pituitary structure in magnetic resonance imaging (MRI), a control analysis was carried out in children with PSIS. Fifty-nine children were subdivided into two groups: group I (partial PSIS, 20 cases) and group II (complete PSIS, 39 cases). There was a significantly small anterior pituitary in both groups of PSIS compared with controls (P < 0.001). The incidence of ectopic posterior pituitary (EPP) was significantly higher in group II (P < 0.001). Before and after hormone replacement therapy, pituitary functions were measured and compared with controls. The levels of growth hormone (GH), free thyroxine (FT4), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), and cortisol (COR) were significantly lower in group II (P < 0.05). The dosage of levothyroxine sodium in group II was significantly higher than in group I (P < 0.01). Conclusion. On the basis of birth history, breech presentation may a forewarning for subsequent pituitary hormone deficiencies. Grades of MRI can predict occurrence and severity of PSIS, which are also correlated with the levels of the pituitary target hormone deficiencies. Interruption of pituitary stalk and ectopic posterior pituitary both represent important markers of pituitary structure and function.

Height, BMI, and pituitary volume in individuals with and without isolated cleft lip and/or palate

INTRODUCTION

Individuals with isolated cleft lip and/or palate (ICLP) are often reported to be of shorter stature relative to peers, and the objective of this study was to explore the role of the pituitary in relationship to growth.

METHODS

Fifty-five males and 32 females with ICLP were compared to 121 healthy males and 158 healthy females with respect to height and BMI. Magnetic resonance imaging (MRI) scans were obtained from all ICLP participants and 47% of healthy group participants.

RESULTS

Males with ICLP were shorter than healthy males and had lower BMI. However, the trajectories for height and BMI did not differ between groups. Analyses in a separate sample of adult males suggested that height normalizes in males with ICLP in their early 30s. There were no differences in mean pituitary volume and pituitary trajectories between male groups. Females with ICLP were shorter than healthy females and also had slower growth rates. They did not differ in mean BMI or BMI trajectories. Furthermore, there were no differences in mean pituitary volume, or in pituitary trajectories.

DISCUSSION

Our findings suggest that there are no gross morphological differences in pituitary volume in individuals with ICLP, although more subtle differences may exist.

Likelihood of persistent GH deficiency into late adolescence: relationship to the presence of an ectopic or normally sited posterior pituitary gland

OBJECTIVES

The presence of an ectopic posterior pituitary gland (EPP) in childhood is associated with isolated GH deficiency (IGHD) and multiple pituitary hormone deficiency. GHD in late adolescence has been defined as a peak GH level <5 microg/l. The aim of this study was to identify the likelihood of persistent GHD in late adolescence in patients with an EPP compared with those with a normally sited posterior pituitary (NPP).

METHODS

In 18 patients with an EPP and 15 patients with an NPP, clinical, biochemical and radiographic data were collected.

RESULTS

In the EPP vs. the NPP group, the change in peak GH levels at the end of growth was less (+0.4[95% confidence interval (CI) - 0.8 to 2.7] vs. +4.1[95%CI + 0.4 to +10.5] microg/l, P-value for ancova = 0.03, after adjustment for age and sex). Using a peak GH level of <5 microg/l as a cut-off for GHD, 66% of EPP subjects compared with 40% of NPP subjects had GHD (P = 0.3). Hundred per cent of EPP subjects had a peak GH level on retesting <10 microg/l, compared with 40% of NPP subjects (P < 0.001).

CONCLUSION

It is important to document GH status at the end of growth, even if there is a structural abnormality of the hypothalamic-pituitary axis. The presence of an EPP compared to an NPP increases the likelihood of persistent GHD by 26%. As all EPP patients had a peak GH level of <10 microg/l, the cut-off for persistent GHD in late adolescence may need to be revised.

Associations with multiple pituitary hormone deficiency in patients with an ectopic posterior pituitary gland

INTRODUCTION

The presence of an ectopic posterior pituitary gland (EPP) on magnetic resonance imaging (MRI) is associated with hypopituitarism with one or more hormone deficiencies. We aimed to identify risk factors for having multiple pituitary hormone deficiency (MPHD) compared to isolated growth hormone deficiency (IGHD) in patients with an EPP.

METHODS

In 67 patients (45 male) with an EPP on MRI, the site (hypothalamic vs. stalk) and surface area (SA) [ x (maximum diameter/2) x (maximum height/2), mm(2)] of the EPP were recorded and compared in patients with IGHD and MPHD in relation to clinical characteristics.

RESULTS

In MPHD (n = 32) compared to IGHD (n = 35) patients: age of presentation was younger (1.4 [0.1-10.7]vs. 4.0 [0.1-11.3] years, P = 0.005), major incidents during pregnancy were increased (47%vs. 20%, P = 0.02) as were admissions to a neonatal intensive care unit (NICU) (60%vs. 26%, P = 0.04), whilst EPP SA was lower (12.3 [2.4-34.6]vs. 25.7 [6.9-48.2] mm(2), P < 0.001). In patients with a hypothalamic (n = 56) compared to a stalk sited EPP (n = 11): prevalence of MPHD was greater (55%vs. 9%,P = 0.05) and EPP surface area was smaller (17.3 [2.4-48.2]vs. 25.3 [11.8-38.5] mm(2), P < 0.001). In regression analysis, after adjusting for age, presence of MPHD was associated with: major incidents during pregnancy (RR 6.8 [95%CI 1.2-37.7]), hypothalamic EPP site (RR 10.9 [1.0-123.9]) and small EPP SA (RR 2.5 [1.0-5.0] for tertiles of SA).

CONCLUSION

In patients with an EPP, adverse antenatal events, size (small) and position (hypothalamic) of the posterior pituitary gland on MRI were associated with MPHD. These findings suggest that adverse factors during pregnancy may be important for the development of an EPP.

Molecular analysis of PROP1, PIT1, HESX1, LHX3, and LHX4 shows high frequency of PROP1 mutations in patients with familial forms of combined pituitary hormone deficiency

Combined Pituitary Hormone Deficiency (CPHD) is a prevalent disease in Neuroendocrinology services. The genetic form of CPHD may originate from mutations in pituitary transcription factor (PTF) genes and the pituitary image in these cases may give a clue of what PTF is most probably mutated: defects in LHX4 are usually associated with ectopic posterior pituitary (EPP); defects in LHX3, PIT1, and PROP1, with normally placed posterior pituitary (NPPP); HESX1 mutations are associated with both.

OBJECTIVE

To identify mutations in PTF genes in patients with idiopathic hypopituitarism followed in our service, based on the presence or absence of EPP on sellar MRI.

METHODS

Forty patients with idiopathic hypopituitarism (36 families, 9 consanguineous), followed in the Neuroendocrinology Outpatient Clinic of UNIFESP, Brazil, were submitted to sequencing analyses of PTF genes as follows: LHX3, HESX1, PIT1, and PROP1 were sequenced in patients with NPPP (26/40) and HESX1 and LHX4 in patients with EPP (14/40).

RESULTS

We identified only PROP1 mutations in 9 out of 26 patients with CPHD and NPPP (35%). Since eight of them came from 4 consanguineous families, the prevalence of PROP1 mutations was higher when only consanguineous families were considered (44%, 4/9). At the end of the study, we decided to sequence PROP1 in patients with EPP, just to confirm that they were not candidates for PROP1 mutations. No patients with EPP had PROP1 or other PTF mutations.

CONCLUSIONS

Patients with idiopathic CPHD and NPPP, born from consanguineous parents, are the strong candidates for PROP1 mutations. Other developmental gene(s) may be involved in the genesis of idiopathic hypopituitarism associated with EPP.

Fast acquisition sagittal T1 magnetic resonance imaging (FAST1-MRI): a new imaging approach for the diagnosis of growth hormone deficiency

Routine magnetic resonance imaging (MRI) is an established standard method to investigate the etiology of pituitary insufficiency. Among the anatomic abnormalities usually observed, ectopic hyperintense signal on T1 sequence is the most frequently associated with pituitary dysfunction. We developed a new protocol (FAST1-MRI) which is able to detect anatomic hypothalamic-pituitary abnormalities with 100% concordance when compared to the routine MRI protocol. FAST1-MRI takes only 3.25 minutes, and is performed without contrast, sedation or anesthesia. We studied 17 controls and 31 patients with growth hormone (GH) deficiency (18/31 with abnormal MRI). Patients with ectopic hyperintense signal were shorter in height, had lower IGF-I and IGFBP-3 levels, and reduced GH response after clonidine. In conclusion, we describe a new simplified MRI protocol that we propose should be used in the diagnosis of GH deficiency.

Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment

Advances in molecular biology have led to the identification of mutations within several novel genes associated with the phenotype of isolated growth hormone deficiency, combined pituitary hormone deficiency, and syndromes such as septo-optic dysplasia. Progress has also been made in terms of the optimum diagnosis of disorders of stature and their treatment. The use of growth hormone for the treatment of adults with growth hormone deficiency and conditions such as Turner's syndrome, Prader-Willi syndrome, intrauterine growth restriction, and chronic renal failure has changed the practice of endocrinology, although cost-benefit implications remain to be established.