5 years ago

Potential utility of FLAIR in MRI-negative Cushing's disease.

Chittiboina, Patronas, Nieman, Smirniotopoulos, Chatain, Ray-Chaudhury, Benzo, Stratakis, Lodish, Sharma, Piazza
OBJECTIVE Accurate presurgical localization of microadenomas in Cushing's disease (CD) leads to improved remission rates and decreased adverse events. Volumetric gradient recalled echo (3D-GRE) MRI detects pituitary microadenomas in CD in up to 50%-80% cases as a focus of hypointensity due to delayed contrast wash-in. The authors have previously reported that postcontrast FLAIR imaging may be useful in detecting otherwise MRI-negative pituitary microadenomas as foci of hyperintensity. This reflects theoretically complementary imaging of microadenomas due to delayed contrast washout. The authors report on the diagnostic accuracy and clinical utility of FLAIR imaging in the detection of microadenomas in patients with CD. METHODS The authors prospectively analyzed imaging findings in 23 patients (24 tumors) with biochemically proven CD who underwent transsphenoidal surgery for CD. Preoperatively, the patients underwent pituitary MRI with postcontrast FLAIR and postcontrast 3D-GRE sequences. RESULTS Postcontrast FLAIR hyperintensity was detected in macroadenomas, and in 3D-GRE-positive or -negative microadenomas. Overall, 3D-GRE was superior in detecting surgically and histopathologically confirmed, location-concordant microadenomas. Of 24 pituitary adenomas, 18 (75%; sensitivity 82%, positive predictive value 95%) were found on 3D-GRE, and 13 (50% [1 was false positive]; sensitivity 55%, positive predictive value 92%) were correctly identified on FLAIR. The stand-alone specificity of 3D-GRE and FLAIR was similar (50%). These results confirm the superiority of 3D-GRE as a stand-alone imaging modality. The authors then tested the utility of FLAIR as a complementary tool to 3D-GRE imaging. All 5 patients with negative 3D-GRE MRI displayed a distinct focus of FLAIR enhancement. Four of those 5 cases (80%) had location-concordant positive histopathological results and achieved postsurgical biochemical remission. The remaining patient was not cured, because resection did not include the region of FLAIR hyperintensity. CONCLUSIONS This study suggests that delayed microadenoma contrast washout may be detected as FLAIR hyperintensity in otherwise MRI-negative CD cases. The authors propose adding postcontrast FLAIR sequences to complement 3D-GRE for surgical planning in patients with CD. Clinical trial registration no.: NIH protocol 03-N-0164, NCT00060541 (clinicaltrials.gov).

Publisher URL: http://doi.org/10.3171/2017.4.JNS17234

DOI: 10.3171/2017.4.JNS17234

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.