Current imaging techniques for the diagnosis of pituitary adenoma

ABSTRACT

Stepwise improvements in the imaging of pituitary adenomas in the last 100 years have had a tremendous impact on patient care. Pituitary tumors are now diagnosed earlier in the time course of the disease, improving chances of endocrine and visual recovery. There is improved pre-surgical planning due to a better understanding of the investment of the tumor around important surrounding parasellar structures. Approaches to tumors are now safer due to stereotactic navigation and residual disease can be radiographically followed for a lifetime and treated prior to irreversible neurological damage. Furthermore, adjuvant radiotherapy can be more precisely delivered to the tumor bed with the aid of higher resolution images. Thanks to these incremental improvements previously formidable macroadenomas, which carried a high risk for morbidity and residual disease, can now be treated safely and effectively. Here, we review modern imaging modalities used to diagnose pituitary adenomas, and identify areas for further improvement.

KEYWORDS:

• Pituitary
• adenoma
• imaging
• transsphenoidal
• endoscopic
• MRI
• CT
• PET

Financial and competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Key issues

• The earliest imaging for pituitary adenoma was performed in the early 1900s using X-rays.

• Later developments included pneumoencephalography.

• Imaging for pituitary adenomas has undergone a revolution since the 1970s.

• Current standards of care include high-resolution MRI for pituitary adenoma.

• CTA may be a useful imaging modality for patients with pituitary adenoma.

• Distinguishing pathology from normal pituitary gland remains challenging, even with modern developments.

• Metabolic imaging modalities such as PET have an important but limited role in pituitary imaging.

• MRe to determine pituitary tumor consistency may become more common.