Three-dimensional magnetic resonance volumetry of the pituitary gland is effective in detecting short stature in children

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.

Pituitary gland volumes in children with normal endocrine function

BACKGROUND

Magnetic resonance imaging (MRI) is often the first modality of choice in the detection of pituitary pathologies due to its excellent contrast resolution and high spatial resolution. However, evaluating the size of the pituitary gland is somewhat difficult since the gland morphology varies widely among individuals.

OBJECTIVE

The aim of this study was to provide normal reference values for pituitary volumes in the pediatric population using three-dimensional (3-D) MRI data. We also aimed to compare the volumetric data measured through 3-D images with the mathematical volumes obtained by the ellipsoid formula from 2-D images, considering the demographic subgroups of age and sex.

MATERIALS AND METHODS

This study was performed retrospectively using PACS-archived brain MRIs obtained in the Pediatric Radiology Unit. Eight hundred children under the age of 18 who underwent brain MRI between January 2014 and May 2018 for headaches, seizures or trauma and who had no brain anomaly or endocrine pathology were recruited. Pituitary volumes were separately calculated from those brain MRIs by means of ellipsoid formula and volumetry. The mean, standard deviation, maximum and minimum and median values were achieved for each 1-year age group in both sexes. Normal reference ranges containing 5th -10th -25th -50th -75th -90th -95th percentiles of volumetric pituitary values were tabulated.

RESULTS

Pituitary gland volumes in both sexes were found to increase gradually with age. The average 3-D volume values were greater in girls than boys except for the age groups 1-2 years and 8-9 years. Pituitary volumes showed a growth spurt during early puberty, which was more prominent in girls. Moreover, a strong positive correlation was noted between the 2-D calculated and 3-D measured volumes in both sexes.

CONCLUSION

Normative data obtained through this study can be used for clinical diagnostic purposes as well as a reference for future research. The 2-D calculated volumes be used where it is not possible to obtain 3-D volumetric values.

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.

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.

Clinical benefits of sex steroids given as a priming prior to GH provocative test or as a growth-promoting therapy in peripubertal growth delays: Results of a retrospective study among ENDO-ERN centres

OBJECTIVES

Sex steroids, administered as a priming before GH stimulation tests (GHST) to differentiate between growth hormone deficiency (GHD) and constitutional delay of growth and puberty (CDGP) or as growth-promoting therapy using low-dose sex steroids (LDSS) in CDGP, are much debated. We aimed to compare auxological outcomes of CDGP or GHD children undergoing primed or unprimed GHST and to evaluate LDSS treatment in CDGP.

DESIGN

Retrospective study among three paediatric University Hospitals in Italy and UK.

METHODS

184 children (72 females) aged 12.4 ± 2.08 years underwent primed (/P⁺ ) or unprimed (/P^- ) GHST and were followed up until final height (FH). CDGP patients were untreated (CDG P^- ) or received LDSS (CDGP⁺ ). The cohort included 34 CDG P^- /P⁺ , 12 CDGP⁺ /P⁺ , 51 GHD/P⁺ , 29 CDG P^- /P^- , 2 CDGP⁺ /P^- and 56 GHD/P^- . FH standard deviation score (SDS), Δ SDS FH-target height (TH) and degree of success (-1 ≤ Δ SDS FH-SDS TH ≤ +1) were outcomes of interest.

RESULTS

GHD/P⁺ had better FH-SDS (-0.87 vs -1.49; P = .023) and ΔSDS FH-TH (-0.35 vs -0.77; P = .002) than CDGP^- /P⁺ . Overall, GHD/P⁺ showed the highest degree of success (90%, P = .006). Regardless of priming, both rhGH and LDSS improved degree of success compared to no treatment (89% and 86% vs 63%, P = .0009). GHD/P⁺ showed a trend towards a higher proportion of permanent GHD compared to GHD/P^- (30.43% vs 15.09%; P = .067).

CONCLUSION

In peripubertal children, priming before GHST improves diagnostic accuracy of GHST for idiopathic GHD. LDSS treatment improves auxological outcomes in CDGP.

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.

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.

The prevalence and volumetry of pituitary cysts in children with growth hormone deficiency and idiopathic short stature

Background Pituitary cysts have been speculated to cause endocrinopathies. We sought to describe the prevalence and volumetry of pituitary cysts in patients with growth hormone deficiency (GHD) and idiopathic short stature (ISS). Methods Six hundred and eighteen children evaluated for growth failure at the Division of Pediatric Endocrinology at New York Medical College between the years 2002 and 2012, who underwent GH stimulation testing and had a brain magnetic resonance imaging (MRI) prior to initiating GH treatment were randomly selected to be a part of this study. High resolution MRI was used to evaluate the pituitary gland for size and the presence of a cyst. Cyst prevalence, cyst volume and percentage of the gland occupied by the cyst (POGO) were documented. Results Fifty-six patients had a cyst, giving an overall prevalence of 9.1%. The prevalence of cysts in GHD patients compared to ISS patients was not significant (13.5% vs. 5.7%, p=0.46). Mean cyst volume was greater in GHD patients than ISS patients (62.0 mm3 vs. 29.4 mm3, p=0.01). POGO for GHD patients was significantly greater (p=0.003) than for ISS patients (15.3%±12.8 vs. 7.1%±8.0). Observers were blinded to patient groups. Conclusions GHD patients had a significantly greater volume and POGO compared to ISS patients. This raises the question of whether cysts are implicated in the pathology of growth failure.

Study of Pituitary Morphometry Using MRI in Indian Subjects

AIM

To establish normative measurements of pituitary gland in Indian population.

MATERIAL AND METHODS

In this cross-sectional study, we measured dimensions of pituitary gland in 482 (213 females and 269 males) Indian subjects with apparently normal pituitary gland function. Mid-sagittal T1-weighted image (T1-WI) on magnetic resonance imaging (MRI) was used to measure height and length of pituitary gland. Pituitary gland width was measured using coronal T1-WI and pituitary gland volume was calculated.

RESULTS

Mean height, length and calculated volume of pituitary gland was significantly higher in females compared to males (p = <0.001, P = 0.03 and P = <0.001, respectively) when all age groups were combined but pituitary gland width was not statistically different in male and female subjects. When subjects were divided into different age groups, except for 10-14 years age group where pituitary height was significantly higher in females as compared to male, no significant difference was observed between male and female in any of the parameters (height, length, width and volume). The mean pituitary gland height was 5.80 ± 1.32 mm and 5.37 ± 1.25 mm in female and male subjects, respectively. Females achieved peak pituitary gland height in 10 to 14-year age group, while males achieved their peak pituitary gland height in 15 to 19-year age group.

CONCLUSION

Our study provides age and sex wise normative data for pituitary measurements derived from Indian population.

Pituitary height at magnetic resonance imaging in pediatric isolated growth hormone deficiency

BACKGROUND

Magnetic resonance imaging (MRI) is used for neuroradiologic evaluation of patients with idiopathic growth hormone deficiency (IGHD).

OBJECTIVES

To compare pituitary height and morphology at MRI between patients with IGHD and controls.

MATERIALS AND METHODS

This retrospective study was conducted in pediatric patients, 3 years-15 years old, who had had brain MRI with non-contrast-enhanced midsagittal T1-weighted images. These images were measured for pituitary height and morphology of the pituitary gland including shape, stalk and posterior pituitary bright spot was evaluated.

RESULTS

One hundred and nineteen patients were included, with 49 and 70 patients assigned to the study and control groups, respectively. Mean pituitary height was significantly less in the IGHD group than in the control group (3.81 mm±1.38 vs. 4.92 mm±1.13, retrospectively; P<0.001). Subgroup analysis revealed a significant difference in the pituitary height between groups in the prepubertal (8-10 years) and pubertal (11-13 years) periods (P=0.039 and P=0.006, respectively) and a trend toward significance in the postpubertal period (P=0.053). There was a significant difference in pituitary shape between IGHD and controls when combining grades III, IV and V (P=0.007). Other abnormal MRI findings of the pituitary stalk and posterior bright spot were significantly more often observed in the IGHD group (P<0.05).

CONCLUSION

Pituitary height was significantly smaller in patients with IGHD than in controls during prepuberty and puberty. Abnormal concave superior contour, hypoplastic stalk and absent/ectopic posterior bright spot were observed significantly more often among patients with IGHD.