CONTRIBUTION OF MRI IN THE EXPLORATION OF CHILDREN

HYPOPITUITARISM

M. ALOUI, N. AIDI, W. DOUIRA-KHOMSI, A. EL GHAZALY, H. LOUATI, L. BEN HASSINE, L. LAHMAR, I. BELLAGHA

Department of Pediatric Radiology, Bechir Hamza children’s Hospital

5th Arab Radiological Congress of the Pan Arab Association of Radiological

Hammamet, 26-28 April 2012PED1

INTRODUCTION

Hypopituitarism refers to the absence or reduction in function of

hormones produced by the pituitary gland

It may be idiopathic or associated with organic causes, such as

tumor, surgery, or irradiation of the sellar area

Early diagnosis and treatment promote the best possible outcomes

Magnetic resonance imaging (MRI) retains an important place in

the diagnostic and therapeutic approach of hypopituitarism

OBJECTIVES

Illustrate through 14 observations, the contribution of

MRI in the exploration of children pituitary insufficiency

Review the role of MRI in the morphological exploration

of the sellar region and the detection of the associated

brain damage

PATIENTS AND METHODS 

Retrospective study involved 14 children monitored for non

tumoral-hypopituitarism including 13 with clinical growth retardation

and one with hypogonadism. All of them have a pituitary MRI

Patients were admitted to this study only if MRI revealed anterior

pituitary hypoplasia

PATIENTS AND METHODS 

Technique

MR studies were performed with a 1.5-T (GE Medical System)

All patients were explored with the same protocol at the level of

the pituitary

Sagittal and coronal T1-weighted spin echo images

Sagittal or coronal T2-weighted fast spin echo images

T1-weighted sequences after intra venous administration of

contrast agent if pituitary stalk was not seen

PATIENTS AND METHODS 

The height of the pituitary gland was determined on the midsagittal

T1-weighted image by measuring the greatest distance between the

base and the top of the gland

Pituitary height measurements were compared with published

normal values for age

A pituitary was considered to be hypoplasic when the gland height

was less than -2 SD for age

RESULTS  Age range: 2 to 17 years (at the time of MRI)

Sex: 8 males, 6 females

Absence of family history of hypopituitarism for all patients

Hormonal assessment

Isolated Growth hormone deficiency (IGHD) in 8 cases

Multiple pituitary hormone deficiencies (MPHD) in 2 cases

Was not realized in 4 cases

RESULTS

MRI performed showed

Pituitary hypoplasia in all patients

Combination with other types of brain damage in 8 cases

specified as shown

Disruption of the pituitary stalk in 3 cases (2 with MPHD and 1

without hormonal assessment)

Ectopic posterior pituitary in 3 cases

Chiari I malformation in 1 case

Small size of the corpus callosum with arachnoid cyst in 1 case

Fig. 1 : 17-year-old boy with growth and pubertal failure: MRI: midsagittal T2 and T1-

weighted images, midsagittal and coronal T1-weighted enhancement images show a small

anterior pituitary gland (2.8 mm height) (red arrow). Posterior pituitary (yellow arrow) and stalk

(green arrow) are normal

RESULTS

Fig. 2: 8-year-old girl with growth failure : MRI: coronal and midsagittal T1-weighted images

show a small anterior pituitary (2.4 mm height) (yellow arrow) and an ectopic posterior pituitary

(orange arrow) seen as an area of high signal intensity in place of the pituitary stalk which is not

visible

RESULTS

A

Fig. 3 : 9-year-old boy with growth failure : MRI: coronal T2-weighted and midsagittal T1-

weighted images show a small anterior pituitary (2.5 mm height) (yellow arrow) and Chiari I

malformation (orange arrow). Sagittal T2-weighted MR medular image was normal

RESULTS

Fig. 4 : 9-year-old boy with hypogonadism and a MPHD in the hormonal assessment : MRI:

unenhanced midline sagittal T1 and enhanced coronal T1-weighted images show a small

anterior pituitary (3 mm height) (yellow arrow), ectopic posterior pituitary seen as an area of high

signal intensity in the midline at the median eminence (orange arrow). The thin stalk is only seen

after injection of gadolinium (green arrow)

RESULTS

Fig. 5: 3-year-old boy with facial dysmorphism and growth failure: MRI: midsagittal T1-

weighted and coronal T2-weighted images show small anterior pituitary gland (1.9 mm height)

(yellow arrow), small size of the corpus callosum (green arrow) and temporal arachnoid cyst

(orange arrow)

B

RESULTS

DISCUSSION Childhood hypopituitarism may be present at birth or may be

acquired

In childhood hypopituitarism, GH is the most commonly

underproduced pituitary hormone

The diagnosis of hypopituitarism must integrate clinical data and

appropriate hormonal testing

Once the diagnosis of hypopituitarism has been made a head

MRI scan must be performed to look for a possible organic or

structural basis

Laboratory diagnosis is not always easy, the IGHD may be

transitory MRI occurs early in the diagnostic strategy, often

before laboratory confirmation of the pituitary  deficiency

MRI can be used to study the anatomic details of the pituitary-

hypothalamic region

The prevalence of morphologic abnormalities in the pituitary

gland is greater in patients with combined pituitary hormone

deficiency than in those with IGHD

DISCUSSION

Hypopituitarism can be classified in two groups

Congenital Hypopituitarism

Features: hypoglycemia+++ / small penis at birth/

noninfectious form of hepatitis

Causes: birth trauma and/ or asphyxia as part of one of a

number of midline anatomical defects / genetic mutation

A congenital basis is strongly suggested by the presence of a

transected pituitary stalk on MRI

DISCUSSION

Acquired Hypopituitarism

Causes

Tumor ++: The most common tumor in this region in

childhood is craniopharyngioma

Radiation treatment of a cancerous tumor in the head or

neck region

Other causes: brain infection (encephalitis and/ or

meningitis), hydrocephalus (even without an underlying

tumor), vascular abnormalities and major head trauma

DISCUSSION

Abnormalities that can be associated with congenital

hypopituitarism include

A small pituitary gland with filling of the sella with cerebrospinal fluid

(empty sella)

Ectopic posterior pituitary gland

Pituitary stalk transection syndrome (lack of pituitary stalk visibility,

hypoplasia of the anterior hypophysis, ectopic posterior pituitary

gland)

Small optic nerves, hydrocephalus, vascular abnormalities

Midline CNS malformations (optic nerve hypoplasia, Chiari

malformation, absence of the septum pellucidum and/ or the corpus

callosum)

DISCUSSION

Diagnosis of tumor in the hypothalamic-pituitary area

(craniopharyngioma+++)

Lateral skull-ray : erosion of the normal sellar architecture and/ or

the presence of suprasellar calcification

MRI show : mixture of solid and cystic components and may

contain a ring of calcification around a cystic component

DISCUSSION

Pituitary function was more severely impaired in the patients with

pituitary stalk interruption syndrome (MPHD)

In contrast, in the patients with isolated pituitary hypoplasia, GH

secretion was less severely impaired (IGHD)

Correlation between the morphology of the hypothalamic-pituitary axis

and endocrine disease severity

T1 weighted sequences are the cornerstone of the morphological

analysis of the pituitary

The injection of gadolinium is more sensitive to visualize the pituitary

stalk when it is not seen before injection

DISCUSSION

Treatment of Hypopituitarism

If an underlying cause is discovered on the MRI of the head, such

as a tumor and/ or hydrocephalus, appropriate neurosurgical

intervention is required

Identified hormone abnormalities require treatment with

appropriate hormonal replacement therapies

DISCUSSION

CONCLUSION Non-tumor etiology constitutes a major group of childhood

hypopituitarism

MRI abnormalities correlated with the severity of growth hormone

deficiency

These abnormalities are more prevalent in patients with MPHD

than in IGHD

The presence of anterior pituitary hypoplasia should alert the

radiologist to the possibility of associated cerebral malformations

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