Imaging of the pituitary: Recent advances

Abstract

Pituitary lesions, albeit relatively infrequent, can significantly alter the quality of life. This article highlights the role of advanced imaging modalities in evaluating pituitary-hypothalamic axis lesions. Magnetic resonance imaging (MRI) is the examination of choice for evaluating hypothalamic-pituitary-related endocrine diseases. Advanced MR techniques discussed in this article include dynamic contrast-enhanced MRI, 3T MRI, magnetization transfer (MT) imaging, diffusion-weighted imaging (DWI), proton MR spectroscopy, fluorine-18 fluorodeoxyglucose-positron emission tomography, single-photon emission computed tomography, intraoperative MRI, and intraoperative real-time ultrasonography.

Acromegaly with normal pituitary MRI

“…When a pituitary micro adenoma is suspected, dynamic contrast-enhanced techniques, which offer better tumor visualization should be employed (4,5) Dynamic MRI involves obtaining a sequence of T1 weighted images at multiple time points after a bolus injection of intravenous gadolinium. The maximum image contrast between the normal pituitary tissue and microadenomas is attained about 30-60 seconds after the bolus injection of the intravenous contrast (6). Most of the microadenomas initially appear as relatively nonenhancing (dark) lesions within an intensely enhancing pituitary gland (7).…”

Dynamic intraoperative MRI in transsphenoidal resection of pituitary macroadenomas: A quantitative analysis

“…Both studies used cCE images and immediate repeated surgery in case of suspect residual tumor. dCE sequences are widely used in clinical practice because of higher sensitivity in distinguishing normal pituitary gland from micro adenomas (8,9,13,14). This is related to the slower enhancement of microadenomas compared to normal pituitary gland.…”

Incidental Findings and Normal Anatomical Variants on Brain MRI in Children for Primary Headaches

“…Although most adenomas are detected on a nonenhanced MRI, microadenomas may become visible only after contrast injection as they appear dark due to lack of contrast uptake compared to normal pituitary tissue. To demonstrate this finding, MRI is best done within 1 minute of contrast injection, and if delayed (20 min after contrast injection), the tumor may enhance …”