Aug. 05, 2026
For patients with pituitary tumors — especially those with hormone-related conditions such as Cushing disease — getting an accurate diagnosis can be challenging. In patients with Cushing disease, these tumors are often extremely small. And they may not be identified conclusively in up to 40% of patients using standard assessment. In these cases, negative imaging leaves uncertainty about tumor presence and location and results in lower remission rates following surgery.
At Mayo Clinic, a growing suite of advanced imaging approaches is helping close that gap — giving clinicians clearer answers and patients a more confident path forward.
"Improved imaging has a direct impact on care," says Jamie J. Van Gompel, M.D., a neurosurgeon at Mayo Clinic in Rochester, Minnesota. "Better preoperative visualization helps surgeons plan more precisely, avoid unnecessary exploration and focus treatment where it is most likely to succeed."
Expanding what imaging can reveal
While MRI remains the foundation of pituitary imaging, Mayo Clinic teams are using specialized sequences and complementary technologies to enhance what standard scans can show. These techniques are not used for every patient; rather, imaging is tailored on a case-by-case basis.
Why seeing the tumor matters
Una secuencia de interferencia constructiva en estado estacionario identifica un tumor pituitario oculto
Se obtuvieron imágenes de interferencia constructiva en estado estacionario de la glándula pituitaria de una mujer de 39 años con enfermedad de Cushing. La imagen (A) muestra claramente una lesión en la glándula derecha. Sin embargo, en una resonancia magnética estándar (imagen B), el mismo tumor fue mucho más difícil de ver y no estaba bien definido. Posteriormente, el tumor se extirpó mediante cirugía y se confirmó que era la causa de su afección.
Una secuencia STIR revela un adenoma corticotrófico
Una mujer de 67 años con enfermedad de Cushing se sometió a imágenes ponderadas en T2 (A) y a imágenes 3D ponderadas en T1 con contraste (B), que no mostraron un tumor claramente definido. Una resonancia con secuencia de recuperación de inversión con tiempo de inversión corto (STIR) (C) permitió detectar una zona anormal pequeña en la glándula pituitaria. Posteriormente, se confirmó que se trataba de un adenoma corticotrófico.
La tomografía computarizada dinámica con detector de conteo de fotones y con contraste permite identificar adenomas hipofisarios
Una mujer de 67 años con enfermedad de Cushing se sometió a una resonancia magnética preoperatoria con imágenes ponderadas en T1 (izquierda), que no mostró ninguna lesión definida. La tomografía computarizada dinámica con detector de conteo de fotones y con contraste (derecha) muestra dos lesiones claras (flechas) en la glándula pituitaria derecha, que se descubrió que eran adenomas según la evidencia de patología.
Because surgery is often the primary treatment for hormonally active tumors, knowing exactly where a lesion is before surgery matters. When imaging is inconclusive, patients may face additional testing, invasive diagnostic procedures or less targeted surgery.
One such approach is contrast-enhanced CISS/FIESTA imaging, an MRI sequence that improves the visual contrast between pituitary tumors and normal gland tissue. In a Mayo Clinic study of patients with Cushing disease, this technique identified discrete pituitary microadenomas in 94% of cases, compared with 65% identified using conventional contrast-enhanced T1-weighted MRI alone. The tumors also were more clearly defined, helping clinicians distinguish true lesions from surrounding tissue. The study results were published in the American Journal of Neuroradiology in 2025.
Advanced contrast-enhanced T2-weighted STIR imaging takes a different approach. By suppressing signals from the pituitary gland, an adenoma can become more conspicuous. This method may help not only with identifying small lesions but also with defining the extent of tumors, including whether they extend into the cavernous sinus. In published Mayo Clinic research in the American Journal of Neuroradiology in 2026, this technique successfully highlighted tumors that were not visible on standard MRI sequences, including lesions later confirmed during surgery.
In select cases, clinicians also may turn to a photon-counting detector CT. This advanced form of CT imaging provides detailed iodine maps of the pituitary region. This technology is particularly useful when MRI findings are inconclusive. As noted in a recent publication in the American Journal of Neuroradiology, 25 patients with Cushing disease underwent imaging at Mayo Clinic. In these patients, photon-counting detector CT accurately identified 92% of lesions compared with contrast-enhanced MRI, which detected 56% of lesions accurately.
"The real strength lies not in any single test, but in having multiple advanced options available," says Ian T. Mark, M.D., a radiologist at Mayo Clinic in Rochester, Minnesota.
From research to patient care
Several of these imaging techniques are in practice at Mayo Clinic. However, ongoing studies are exploring additional ways to improve tumor detection, particularly for patients whose imaging remains negative despite clear biochemical evidence of disease.
A clearer path forward
The clinical impact of advanced imaging can mean less uncertainty and more confidence in treatment decisions.
By combining clinical expertise and a broad range of imaging capabilities, Mayo Clinic teams are helping ensure that pituitary tumors once considered uncertain or unseen are increasingly identifiable, allowing care to move forward with greater clarity and purpose.
For more information
Mark IT, et al. Contrast-enhanced CISS/FIESTA imaging for increased conspicuity of pituitary microadenomas in Cushing disease. American Journal of Neuroradiology. 2025;46:1255.
Mark IT, et al. Contrast enhanced T2-weighted STIR imaging of pituitary adenomas. American Journal of Neuroradiology. 2026. In press.
Mark IT, et al. Pituitary photon-counting detector CT for Cushing disease: Preoperative lesion localization, intraoperative findings, and postoperative outcomes. American Journal of Neuroradiology. 2025;46:2610.
Brain Tumor Program. Mayo Clinic.
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