Pituitary volume in children with growth hormone deficiency, idiopathic short stature and controls

Small pituitary volume and central nervous system anomalies in Fanconi Anemia

Introduction

Fanconi anemia (FA) is a genomic instability disorder associated with congenital abnormalities, including short stature and the presence of central nervous system anomalies, especially in the hypothalamic-pituitary area. Thus, differences in pituitary size could associate with the short stature observed in these patients. Our aim was to evaluate whether central nervous system abnormalities and pituitary gland volume correlate with height and hormone deficiencies in these patients.

Methods

In this cross-sectional exploratory study 21 patients diagnosed with FA between 2017 and 2022 in a Spanish Reference Center were investigated. Magnetic resonance imaging (MRI) was performed and pituitary volume calculated and corelated with height and other endocrine parameters.

Results

The percentage of abnormalities in our series was 81%, with a small pituitary (pituitary volume less than 1 SD) being the most frequent, followed by Chiari malformation type 1. The median value of pituitary volume was -1.03 SD (IQR: -1.56, -0.36). Short stature was found in 66.7% [CI95% 43-85.4]. Total volume (mm3) increases significantly with age and in pubertal stages. There were no differences between volume SD and pubertal stage, or the presence of endocrine deficiencies. No correlations were found between pituitary volume and the presence of short stature. The intraclass correlation index (ICC) average for volume was 0.85 [CI95% 0.61-0.94] indicating a good-to-excellent correlation of measurements.

Discussion

Central nervous system anomalies are part of the FA phenotype, the most frequent after pituitary hypoplasia being posterior fossa abnormalities, which may have clinical repercussions in the patient. It is therefore necessary to identify those who could be candidates for neurosurgical intervention. The size of the pituitary gland is smaller in these patients, but this does not seem to be related to hormone deficiency and short stature or exposure to a low dose of total body irradiation.

Pitfalls of diagnosing pituitary hypoplasia in the patients with short stature

PURPOSE

Height age (HA) and bone age (BA) delay is well known in the patients with short stature. Therefore assessing pituitary hypoplasia based on chronological age (CA) might cause overdiagnosis of pituitary hypoplasia. We aimed to investigate the diagnostic and prognostic value of the PH and PV based on CA, HA, or BA in the patients with GHD.

METHODS

Fifty-seven patients with severe and 40 patients with partial GHD and 39 patients with ISS assigned to the study. For defining the most accurate diagnosis of pituitary hypoplasia, PH and PV were evaluated based on CA, BA and HA. The relationship of each method with clinical features was examined.

RESULTS

The mean PV was significantly larger in patients with ISS compared to the GH-deficient patients. PV was more correlated with clinical features including height SDS, stimulated GH concentration, IGF-1 and IGFBP-3 SDS, height velocity before and after rGH therapy. We found BA-based PV could discriminate GHD from ISS (Sensitivity: 17%, specificity: 98%, positive predictive value: 94%, negative predictive value: 39%), compared to the other methods based on PH or PV respect to CA and HA. 3% of patients with ISS, 17% of patients with GHD had pituitary hypoplasia based on PV-BA.

CONCLUSION

PV based on BA, has the most accurate diagnostic value for defining pituitary hypoplasia. But it should be kept in mind that there might be still misdiagnosed patients by this method. PV is also a significant predictor for the rGH response.

Pituitary MRI Radiomics Improves Diagnostic Performance of Growth Hormone Deficiency in Children Short Stature: A Multicenter Radiomics Study

RATIONALE AND OBJECTIVES

To develop an efficient machine-learning model using pituitary MRI radiomics and clinical data to differentiate growth hormone deficiency (GHD) from idiopathic short stature (ISS), making the diagnostic process more acceptable to patients and their families.

MATERIALS AND METHODS

A retrospective cohort of 297 GHD and 300 ISS children (4-12 years) were enrolled as training and validation cohorts (8:2 ratio). An external cohort from another institution (49 GHD and 51 ISS) was employed as the testing cohort. Radiomics features extracted from the anterior pituitary gland on sagittal T1-weighted image (1.5 T or 3.0 T) were used to develop a radiomics model after feature selection. Hematological biomarkers were selected to create a clinical model and combine with the optimal radiomics features to create a clinical-radiomics model. The area under the receive operating characteristic curve (AUC) and Delong test compared the diagnostic performance of the previously mentioned three models across different validation and testing cohorts.

RESULTS

17 radiomics features were selected for the radiomics model, and total protein, total cholesterol, free triiodothyronine, and triglyceride were utilized for the clinical model. In the training and validation cohorts, the diagnostic performance of the clinical-radiomics model (AUC=0.820 and 0.801) was comparable to the radiomics model (AUC=0.812 and 0.779, both P >0.05), both outperforming the clinical model (AUC=0.575 and 0.593, P <0.001). In the testing cohort, the clinical-radiomics model exhibited the highest AUC of 0.762 than the clinical and radiomics model (AUC=0.604 and 0.741, respectively, P <0.05). In addition, the clinical and radiomics models demonstrated similar diagnostic performance in the testing cohort (P >0.05).

CONCLUSION

Integrating radiomics features from conventional pituitary MRI with clinical indicators offers a minimally invasive approach for identifying GHD and shows robustness in a multicenter setting.

The influence of pituitary volume on the growth response in growth hormone-treated children with growth hormone deficiency or idiopathic short stature

PURPOSE

Magnetic resonance imaging (MRI) can be used for assessing the morphology of the pituitary gland in children with short stature. The purposes of this study were: (1) to determine if pituitary volume (PV) can distinguish patients with growth hormone (GH) deficiency from those with idiopathic short stature (ISS), (2) to validate an association between PV and severity of GH deficiency, and (3) to compare PV between good and poor response groups in children with GH deficiency or ISS after 1 year of treatment.

METHODS

Data were collected from the medical records of 152 children with GH deficiency or ISS who underwent GH stimulation test, sella MRI, and GH treatment for at least 1 year. Estimated PVs were calculated using the formula of an ellipsoid. We compared the PVs in patients with GH deficiency with those of patients with ISS. In addition, we assessed the association between PV and severity of GH deficiency, and we assessed growth response after treatment.

RESULTS

No difference was observed in PV between patients with GH deficiency and those with ISS. The severity of the GH deficiency seemed to be associated with PV (P=0.082), and the height of the pituitary gland was associated with severity of GH deficiency (P<0.005). The PV in the good response group was less than that of the poor response group in patients with GH deficiency (P<0.005), and PV showed no association with responsiveness to GH treatment in patients with ISS (P=0.073).

CONCLUSION

The measurement of PV cannot be used for differential diagnosis between GH deficiency and ISS. In patients with GH deficiency, PV tended to be smaller as the severity of GH deficiency increased, but the difference was not significant. PV may be a good response predictor for GH treatment. Further studies, including a radiomics-based approach, will be helpful in elucidating the clinical implications of pituitary morphology in patients with short stature.

Pituitary T1 signal intensity at magnetic resonance imaging is reduced in patients with obesity: results from the CHIASM study

BACKGROUND

Despite obesity being well known to be associated with several pituitary hormone imbalances, pituitary appearance in magnetic resonance imaging (MRI) in patients with obesity is understudied.

OBJECTIVE

To evaluate the pituitary volume and signal intensity at MRI in patients with obesity.

METHODS

This is a prospective study performed in an endocrine Italian referral center (ClinicalTrial.gov Identifier: NCT03458533). Sixty-nine patients with obesity (BMI > 30 kg/m2) and twenty-five subjects without obesity were enrolled. Thirty-three patients with obesity were re-evaluated after 3 years of diet and lifestyle changes, of whom 17 (51.5%) achieved a > 5% loss of their initial body weight, whereas the remaining 16 (48.5%) had maintained or gained weight. Evaluations included metabolic and hormone assessments, DEXA scan, and pituitary MRI. Pituitary signal intensity was quantified by measuring the pixel density using ImageJ software.

RESULTS

At baseline, no difference in pituitary volume was observed between the obese and non-obese cohorts. At the 3-year follow-up, pituitary volume was significantly reduced (p = 0.011) only in participants with stable-increased body weight. Furthermore, a significant difference was noted in the mean pituitary intensity of T1-weighted plain and contrast-enhanced sequences between the obese and non-obese cohorts at baseline (p = 0.006; p = 0.002), and a significant decrease in signal intensity was observed in the subgroup of participants who had not lost weight (p = 0.012; p = 0.017). Insulin-like growth factor-1 levels, following correction for BMI, were correlated with pituitary volume (p = 0.001) and intensity (p = 0.049), whereas morning cortisol levels were correlated with pituitary intensity (p = 0.007). The T1-weighted pituitary intensity was negatively correlated with truncal fat (p = 0.006) and fibrinogen (p = 0.018).

CONCLUSIONS

The CHIASM study describes a quantitative reduction in pituitary intensity in T1-weighted sequences in patients with obesity. These alterations could be explained by changes in the pituitary stromal tissue, correlated with low-grade inflammation.

The evolution of pituitary cysts in growth hormone-treated children

OBJECTIVES

We have previously shown that pituitary cysts may affect growth hormone secretion. This study sought to determine cyst evolution during growth hormone treatment in children.

METHODS

Forty-nine patients with short stature, a pituitary cyst, and at least two brain MRI scans were included. The percent of the pituitary gland occupied by the cyst (POGO) was calculated, and a cyst with a POGO of ≤15% was considered small, while a POGO >15% was considered large.

RESULTS

Thirty-five cysts were small, and 14 were large. Five of the 35 small cysts grew into large cysts, while 6 of the 14 large cysts shrunk into small cysts. Of 4 cysts that fluctuated between large and small, 3 presented as large and 1 as small. Small cysts experienced greater change in cyst volume (CV) (mean=61.5%) than large cysts (mean=-0.4%). However, large cysts had a greater net change in CV (mean=44.2 mm³) than small cysts (mean=21.0 mm³). Older patients had significantly larger mean pituitary volume than younger patients (435.4 mm³ vs. 317.9 mm³) and significantly larger mean CV than younger patients (77.4 mm³ vs. 45.2 mm³), but there was no significant difference in POGO between groups.

CONCLUSIONS

Pituitary cyst size can vary greatly over time. Determination of POGO over time is a useful marker for determining the possibility of a pathologic effect on pituitary function since it factors both cyst and gland volume. Large cysts should be monitored closely, given their extreme, erratic behavior.

A Radiomics-Based Model with the Potential to Differentiate Growth Hormone Deficiency and Idiopathic Short Stature on Sella MRI

PURPOSE

We hypothesized that a radiomics approach could be employed to classify children with growth hormone deficiency (GHD) and idiopathic short stature (ISS) on sella magnetic resonance imaging (MRI). Accordingly, we aimed to develop a radiomics prediction model for differentiating GHD from ISS and to evaluate the diagnostic performance thereof.

MATERIALS AND METHODS

Short stature pediatric patients diagnosed with GHD or ISS from March 2011 to July 2020 at our institution were recruited. We enrolled 312 patients (GHD 210, ISS 102) with normal sella MRI and temporally split them into training and test sets (7:3). Pituitary glands were semi-automatically segmented, and 110 radiomic features were extracted from the coronal T2-weighted images. Feature selection and model development were conducted by applying mutual information (MI) and a light gradient boosting machine, respectively. After training, the model's performance was validated in the test set. We calculated mean absolute Shapley values for each of the selected input features using the Shapley additive explanations (SHAP) algorithm. Volumetric comparison was performed for GHD and ISS groups.

RESULTS

Ten radiomic features were selected by MI. The receiver operating characteristics curve of the developed model in the test set was 0.705, with an accuracy of 70.6%. When analyzing SHAP plots, root mean squared values had the highest impact in the model, followed by various texture features. In volumetric analysis, sagittal height showed a significant difference between GHD and ISS groups.

CONCLUSION

Radiomic analysis of sella MRI may be able to differentiate between GHD and ISS in clinical practice for short-statured children.

Anterior Pituitary Volume in Patients with Transfusion Dependent Anemias: Volumetric Approaches and Relation to Pituitary MRI‑R2

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.

MRI Protocol for Pituitary Assessment in Children with Growth or Puberty Disorders-Is Gadolinium Contrast Administration Actually Needed?

The aim of this study was to assess the diagnostic value of non-contrast pituitary MRI in children with growth or puberty disorders (GPDs) and to determine the criteria indicating the necessity to perform post-contrast examination. A retrospective study included re-analysis of 567 contrast-enhanced pituitary MRIs of children treated in a tertiary reference center. Two sets of sequences were created from each MRI examination: Set 1, including common sequences without contrast administration, and Set 2, which included common pre- and post-contrast sequences (conventional MRI examination). The differences in the visibility of pituitary lesions between pairs of sets were statistically analyzed. The overall frequency of Rathke’s cleft cysts was 11.6%, ectopic posterior pituitary 3.5%, and microadenomas 0.9%. Lesions visible without contrast administration accounted for 85% of cases. Lesions not visible before and diagnosed only after contrast injection accounted for only 0.18% of all patients. Statistical analysis showed the advantage of the antero-posterior (AP) pituitary dimension over the other criteria in determining the appropriateness of using contrast in pituitary MRIs. The AP dimension was the most significant factor in logistic regression analysis: OR = 2.23, 95% CI, 1.35–3.71, p-value = 0.002, and in ROC analysis: AUC: 72.9% with a cut-off value of 7.5 mm, with sensitivity/specificity rates of 69.2%/73.5%. In most cases, the use of gadolinium-based contrast agent (GBCA) in pituitary MRI in children with GPD is unnecessary. The advantages of GBCA omission include shortening the time of MRI examination and of general anesthesia; saving time for other examinations, thus increasing the availability of MRI for waiting children; and acceleration in their further clinical management.

Brain MRIs may be of low value in most children diagnosed with isolated growth hormone deficiency

OBJECTIVES

Brain MRIs are considered essential in the evaluation of children diagnosed with growth hormone deficiency (GHD), but there is uncertainty about the appropriate cut-off for diagnosis of GHD and little data about the yield of significant abnormal findings in patients with peak growth hormone (GH) of 7-10 ng/mL. We aimed to assess the frequency of pathogenic MRIs and associated risk factors in relation to peak GH concentrations.

METHODS

In this retrospective multicenter study, charts of patients diagnosed with GHD who subsequently had a brain MRI were reviewed. MRIs findings were categorized as normal, incidental, of uncertain significance, or pathogenic (pituitary hypoplasia, small stalk and/or ectopic posterior pituitary and tumors). Charges for brain MRIs and sedation were collected.

RESULTS

In 499 patients, 68.1% had normal MRIs, 18.2% had incidental findings, 6.6% had uncertain findings, and 7.0% had pathogenic MRIs. Those with peak GH<3 ng/mL had the highest frequency of pathogenic MRIs (23%). Only three of 194 patients (1.5%) with peak GH 7-10 ng/mL had pathogenic MRIs, none of which altered management. Two patients (0.4%) with central hypothyroidism and peak GH<4 ng/mL had craniopharyngioma.

CONCLUSIONS

Pathogenic MRIs were uncommon in patients diagnosed with GHD except in the group with peak GH<3 ng/mL. There was a high frequency of incidental findings which often resulted in referrals to neurosurgery and repeat MRIs. Given the high cost of brain MRIs, their routine use in patients diagnosed with isolated GHD, especially patients with peak GH of 7-10 ng/mL, should be reconsidered.

Development of a predictive model of growth hormone deficiency and idiopathic short stature in children

The aim of the present study was to develop predictive models using clinical features and MRI texture features for distinguishing between growth hormone deficiency (GHD) and idiopathic short stature (ISS) in children with short stature. This retrospective study included 362 children with short stature from Children's Hospital of Hebei Province. GHD and ISS were identified via the GH stimulation test using arginine. Overall, there were 190 children with GHD and 172 with ISS. A total of 57 MRI texture features were extracted from the pituitary gland region of interest using C++ language and Matlab software. In addition, the laboratory examination data were collected. Receiver operating characteristic (ROC) regression curves were generated for the predictive performance of clinical features and MRI texture features. Logistic regression models based on clinical and texture features were established for discriminating children with GHD and ISS. Two clinical features [IGF-1 (insulin growth factor-1) and IGFBP-3 (IGF binding protein-3) levels] were used to build the clinical predictive model, whereas the three best MRI textures were used to establish the MRI texture predictive model. The ROC analysis of the two models revealed predictive performance for distinguishing GHD from ISS. The accuracy of predicting ISS from GHD was 64.5% in ROC analysis [area under the curve (AUC), 0.607; sensitivity, 57.6%; specificity, 72.1%] of the clinical model. The accuracy of predicting ISS from GHD was 80.4% in ROC analysis (AUC, 0.852; sensitivity, 93.6%; specificity, 65.8%) of the MRI texture predictive model. In conclusion, these findings indicated that a texture predictive model using MRI texture features was superior for distinguishing children with GHD from those with ISS compared with the model developed using clinical features.

Nickel Sensitivity Is Associated with GH-IGF1 Axis Impairment and Pituitary Abnormalities on MRI in Overweight and Obese Subjects

Nickel (Ni) is a ubiquitous metal, the exposure of which is implied in the development of contact dermatitis (nickel allergic contact dermatitis (Ni-ACD)) and Systemic Ni Allergy Syndrome (SNAS), very common among overweight/obese patients. Preclinical studies have linked Ni exposure to abnormal production/release of Growth Hormone (GH), and we previously found an association between Ni-ACD/SNAS and GH-Insulin-like growth factor 1 (IGF1) axis dysregulation in obese individuals, altogether suggesting a role for this metal as a pituitary disruptor. We herein aimed to directly evaluate the pituitary gland in overweight/obese patients with signs/symptoms suggestive of Ni allergy, exploring the link with GH secretion; 859 subjects with overweight/obesity and suspected of Ni allergy underwent Ni patch tests. Among these, 106 were also suspected of GH deficiency (GHD) and underwent dynamic testing as well as magnetic resonance imaging for routine follow up of benign diseases or following GHD diagnosis. We report that subjects with Ni allergies show a greater GH-IGF1 axis impairment, a higher prevalence of Empty Sella (ES), a reduced pituitary volume and a higher normalized T2 pituitary intensity compared to nonallergic ones. We hypothesize that Ni may be detrimental to the pituitary gland, through increased inflammation, thus contributing to GH-IGF1 axis dysregulation.

Diagnostic value of pituitary volume in girls with precocious puberty

BACKGROUND

To date, the gonadotropin-releasing hormone (GnRH) stimulation test is still the gold standard for precocious puberty (PP) diagnosis. However, it has many disadvantages, including low sensitivity, high cost, and invasive operation. This study aims to evaluate whether magnetic resonance imaging (MRI)-derived variables, including pituitary volume (PV), could be used as diagnostic factors for PP in girls, providing a non-invasive diagnostic approach for PP.

METHODS

A total of 288 young female patients who presented to the Clinic of Pediatric Endocrinology for evaluation of PP from January 2015 to December 2017 were enrolled. The sample included 90 girls diagnosed with premature thelarche (PT), 133 girls determined as idiopathic central precocious puberty (ICPP), 35 early pubertal girls, and 30 normal girls. All patients received pituitary MRI examinations.

RESULTS

The largest PV and pituitary height were shown in the ICPP and pubertal groups, followed by the PT group. The receiver operating characteristic (ROC) curve analysis showed that PV is a predictive marker for ICPP, with a sensitivity of 54.10% and a specificity of 72.20% at the cutoff value of 196.01 mm³. By univariate analysis, PV was positively associated with peak luteinizing hormone (LH), LH/follicle-stimulating hormone (FSH), age, bone age, and body mass index (BMI) (all P < 0.05). However, bone age and peak LH were the only significant predictors of PV as demonstrated by the stepwise multivariate regression analysis (Model: PV = 9.431 * bone age + 1.230 * peak LH + 92.625 [P = 0.000, R² = 0.159]).

CONCLUSIONS

The PV in the ICPP group was significantly higher than in PT and control groups, but there was no reliable cutoff value to distinguish ICPP from PT. Pituitary MRI should be combined with clinical and laboratory tests to improve the diagnostic value of PV for PP.

Differential diagnosis between constitutional delay of growth and puberty, idiopathic growth hormone deficiency and congenital hypogonadotropic hypogonadism: a clinical challenge for the pediatric endocrinologist

INTRODUCTION

Differential diagnosis between constitutional delay of growth and puberty (CDGP), partial growth hormone deficiency (pGHD) and congenital hypogonadotropic hypogonadism (cHH) may be difficult. All these conditions usually present with poor growth in pre- or peri-pubertal age and they may recur within one familial setting, constituting a highly variable, but somehow common, spectrum of pubertal delay.

EVIDENCE ACQUISITION

Narrative review of the most relevant English papers published between 1981 and march 2020 using the following search terms "constitutional delay of growth and puberty," "central hypogonadism," "priming," "growth hormone deficiency," "pituitary," "pituitary magnetic resonance imaging," with a special regard to the latest scientific acquisitions.

EVIDENCE SYNTHESIS

CDGP is by far the most prevalent entity in boys and recurs within families. pGHD is a rare, often idiopathic and transient condition, where hypostaturism presents more severely. Specificity of pGHD diagnosis is increased by priming children before growth hormone stimulation test (GHST); pituitary MRI and genetic analysis are recommended to personalize future follow-up. Diagnosing cHH may be obvious when anosmia and eunuchoid proportions concomitate. However, cHH can either overlap with pGHD in forms of multiple pituitary hormone deficiencies (MPHD) or syndromic conditions either with CDGP in family pedigrees, so endocrine workup and genetic investigations are necessary. The use of growth charts, bone age, predictors of adult height, primed GHST and low dose sex steroids (LDSS) treatment are recommended.

CONCLUSIONS

Only a step-by-step diagnostic process based on appropriate endocrine and genetic markers together with LDSS treatment can help achieving the correct diagnosis and optimizing outcomes.

A novel diagnostic tool for the evaluation of hypothalamic-pituitary region and diagnosis of growth hormone deficiency: pons ratio

Backgrounds Limitations in the evaluation of the pituitary size and changes according to pubertal status make its validity questionable. Recently, in a small-scale study, pons ratio (PR) has been suggested as a more sensitive tool for diagnosis and etiological evaluation of growth hormone deficiency (GHD). The aim of the study is to evaluate the diagnostic value of PR in the diagnosis of GHD. Methods We retrospectively evaluated the pituitary magnetic resonance imaging (MRI) of 133 patients with a diagnosis of GHD. Primary axis (PA) was assigned as a line crossing the mid-sagittal dorsum sella and fourth ventricle. PR was defined as the pons height above the PA divided by total pons height. The PR of patients with GHD was compared to subjects without GHD. Results Study included 133 patients with GHD and 47 controls. In total, 121 (91%) patients had isolated GHD and 12 (9%) patients had multiple pituitary hormone deficiency. The PR of the patient group (mean: 0.32 ± 0.89; range: 0.14-0.63) was significantly higher than controls (mean: 0.26 ± 0.067; range 0.19-0.44) (p: 0.000). The optimal cut-off value of PR for GHD diagnosis was 0.27 (sensitivity 71% specificity 56%). There was a negative correlation between anterior pituitary height (APH)-SDS and PR (p: 0.002; r: -0.27). APH was increased, but PR remained unchanged in pubertal patients (p: 0.089). Conclusions PR measurement is a noninvasive, practical method with a cost-benefit clinical value. As it is not affected by pubertal status, PR is potentially a more sensitive tool for evaluation of pituitary gland in GHD patients compared to APH.

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.