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High signal intensity of the infundibular stalk on fluid-attenuated inversion recovery MR
Y Araki1, R Ashikaga, S Takahashi
1Department of Radiology, Kinki University, School of Medicine, Osaka, Japan.
Purpose:
To determine the MR imaging characteristics of the pituitary stalk with a fluid-attenuated inversion recovery (FLAIR) technique.
Methods:
We retrospectively studied the prevalence of a high-signal infundibular stalk on FLAIR MR images of the brain in 133 patients and compared this finding with the patients' ages. To understand the cause of the high signal intensity of the pituitary stalk on FLAIR images, we calculated the T1, T2, and proton-density values in regions of gray matter, white matter, and the pituitary stalk in nine cases.
Results:
FLAIR images showed the pituitary stalk as having high signal intensity in 97 (73%) of 133 cases; however, in 11 of 16 patients less than 10 years old, the infundibular stalk was not of high signal intensity. In patients with a high-signal pituitary stalk on FLAIR images, the T2 value of the pituitary stalk was longer than that of gray or white matter.
Conclusion:
High signal intensity of the infundibular stalk was frequently seen on FLAIR MR images of the brain at all ages. A prolonged T2 value of the pituitary stalk caused the high signal intensity, presumably reflecting the fluid component of the pituitary stalk.
Insights
Fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) frequently shows a high-signal pituitary stalk in patients of all ages. This finding is attributed to a prolonged T2 value, likely reflecting the stalk's fluid content.
Area of Science:
- Radiology
- Neuroimaging
- Magnetic Resonance Imaging
Background:
- The pituitary stalk's appearance on MRI can vary.
- Understanding normal imaging characteristics is crucial for detecting pathology.
Purpose of the Study:
- To characterize the MR imaging features of the pituitary stalk using fluid-attenuated inversion recovery (FLAIR).
- To investigate the prevalence and underlying causes of high signal intensity in the pituitary stalk on FLAIR sequences.
Main Methods:
- Retrospective analysis of FLAIR brain MR images from 133 patients.
- Comparison of pituitary stalk signal intensity with patient age.
- Calculation of T1, T2, and proton-density values in the pituitary stalk, gray matter, and white matter in a subset of nine patients.
Main Results:
- High signal intensity of the pituitary stalk was observed in 73% (97/133) of patients.
- The infundibular stalk was not high-signal in 11 of 16 patients under 10 years old.
- Patients with a high-signal pituitary stalk exhibited a longer T2 value compared to gray and white matter.
Conclusions:
- High signal intensity of the infundibular stalk on FLAIR MRI is a common finding across all age groups.
- Prolonged T2 relaxation time of the pituitary stalk is responsible for the high signal intensity on FLAIR images.
- The observed high signal intensity is presumed to be related to the fluid component within the pituitary stalk.