Pituitary Tumors: Advances in Neuroimaging

Abstract

Pediatric pituitary tumors, albeit relatively infrequent, can significantly alter the quality of life of affected children. Accurate diagnostic differentiation is essential for both safe and effective disease management. Recent advances in neuroimaging have enabled the neuroradiologist to study the pituitary region in greater detail than ever before. Magnetic resonance imaging (MRI) represents the examination method of choice for evaluating hypothalamic-pituitary-related endocrine diseases due to its ability to provide strongly contrasted high-resolution, multiplanar and spatial images. Specifically, MRI allows the detection of the pituitary lesions responsible of the clinical picture and offers useful information about the relationship with adjacent anatomical structures in order to plan the medical or surgical strategy. A rigorous imaging exam technique is necessary in order to obtain images of high diagnostic quality. Advanced MR techniques, including diffusion-weighted imaging and MR spectroscopy, may be helpful in particular cases. Computerized tomography (CT) has a complementary role in the identification of intralesional calcifications or to better evaluate bone structures prior to trans-sphenoidal surgery. The aim of this work is to provide an overview of the most relevant neuroradiological features of pituitary region tumors and to propose an appropriate and accurate differential diagnosis.

Imaging response assessment for CNS germ cell tumours: consensus recommendations from the European Society for Paediatric Oncology Brain Tumour Group and North American Children's Oncology Group

“…This finding has been demonstrated to specifically result from the storage of vasopressin [antidiuretic hormone (ADH)], a hormone synthesised by the hypothalamus. 20,21 The bright spot serves as an important marker of neurohypophyseal function and, when present, documents integrity of the hypothalamic-neurohypophyseal tract/axis. The posterior pituitary lobe does not undergo physiological variations in either size or signal intensity during childhood.…”

Neuroimaging of pediatric tumors of the sellar region—A review in light of the 2021 WHO classification of tumors of the central nervous system

“…In particular, dynamic contrast-enhanced T1WI coronal images are used to increase the sensitivity detecting small adenomas within the pituitary as these lesions show delayed enhancement comparing with the normal gland parenchyma. This sequence consists in the injection of a rapid intravenous bolus of paramagnetic contrast at a dose of 0.1 ml/kg followed by sequential imaging every 10–12 s for 60–90 s, 1–2 min after contrast administration ( 18 , 19 ). More recently, 3D gradient-echo T1WI ( 20 ), 3D T2W SPACE ( 21 ), and Fluid Attenuated Inversion Recovery (FLAIR) ( 22 ) sequences after gadolinium administration proved to further improve the detection of ACTH-secreting microadenomas.…”

Target delineation and optimal radiosurgical dose for pituitary tumors

“…Current optimal imaging technique for target delineation requires the use of precontrast and postcontrast magnetic resonance imaging (MRI) sequences to improve the accuracy of target identification and delineation. Contrast-enhanced 3D T1-weighted sequences with 1 mm thin slices are extremely useful for accurate target delineation by allowing identification of subtle enhancement patterns in the surrounding neurovascular structures and along the course of the optic nerve [ 20 ]. For planning purpose, MRI scan is subsequently fused with thin-slice non-contrast enahnaced CT scan.…”