Rapid Progression of Pituitary Hyperplasia in Humans with Primary Hypothyroidism: Demonstration with MR Imaging1
Taro Shimono, MD,
Hiroto Hatabu, MD,
Kanji Kasagi, MD,
Yukio Miki, MD,
Sadahiko Nishizawa, MD,
Takashi Misaki, MD,
Akira Hiraga, RT and
Junji Konishi, MD
1 From the Department of Nuclear Medicine and Radiology, Faculty of Medicine, Kyoto University, 54 Shogoinkawahara-cho Sakyo-ku Kyoto, 606-8507, Japan (T.S., H.H., K.K., Y.M., S.N., T.M., A.H., J.K.), and the Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Mass (H.H.). Received November 20, 1998; revision requested January 18, 1999; revision received February 22; accepted April 15. Address reprint requests to T.S. (e-mail: shimono@kuhp .kyto-u.ac.jp).
View larger version (20K):
[in a new window]
|
Figure 1a. Pituitary gland volumes in 14 patients. Graphs show (a) volume 1 and (b) volume 2 for the euthyroid and hypothyroid states. The hypothyroid state was associated with significantly larger pituitary gland volumes (volume 1 = 453 mm3 ± 109, volume 2 = 626 mm3 ± 173) than was the euthyroid state (volume 1 = 331 mm3 ± 68, volume 2 = 453 mm3 ± 107). Two (patients 2 and 7) of the 14 patients had the same volume 1 (385 mm3 for the euthyroid state and 539 mm3 for the hypothyroid state). In a and b, • indicates the calculated pituitary gland volume,  indicates the mean, and the vertical bar indicates the SD.
|
|
View larger version (20K):
[in a new window]
|
Figure 1b. Pituitary gland volumes in 14 patients. Graphs show (a) volume 1 and (b) volume 2 for the euthyroid and hypothyroid states. The hypothyroid state was associated with significantly larger pituitary gland volumes (volume 1 = 453 mm3 ± 109, volume 2 = 626 mm3 ± 173) than was the euthyroid state (volume 1 = 331 mm3 ± 68, volume 2 = 453 mm3 ± 107). Two (patients 2 and 7) of the 14 patients had the same volume 1 (385 mm3 for the euthyroid state and 539 mm3 for the hypothyroid state). In a and b, • indicates the calculated pituitary gland volume, indicates the mean, and the vertical bar indicates the SD.
|
|
View larger version (143K):
[in a new window]
|
Figure 2a. Patient 7.
Midsagittal T1-weighted images (400/14) of the pituitary gland in the (a) euthyroid and (b) hypothyroid states. The anterior gland (arrow in a and b) is remarkably enlarged in b compared with a.
|
|
View larger version (136K):
[in a new window]
|
Figure 2b. Patient 7.
Midsagittal T1-weighted images (400/14) of the pituitary gland in the (a) euthyroid and (b) hypothyroid states. The anterior gland (arrow in a and b) is remarkably enlarged in b compared with a.
|
|
View larger version (156K):
[in a new window]
|
Figure 3a. Patient 12.
Midsagittal T1-weighted images (400/14) of the pituitary gland in the (a) euthyroid and (b) hypothyroid states. The anterior gland (arrow in a and b) is remarkably enlarged in b compared with a.
|
|
View larger version (160K):
[in a new window]
|
Figure 3b. Patient 12.
Midsagittal T1-weighted images (400/14) of the pituitary gland in the (a) euthyroid and (b) hypothyroid states. The anterior gland (arrow in a and b) is remarkably enlarged in b compared with a.
|
|
View larger version (21K):
[in a new window]
|
Figure 4. Diagram demonstrates that an insufficient quantity of thyroid hormones results in lack of inhibition of thyrotropin-releasing hormone (TRH) and thyrotropin (TSH). Increased thyrotropin-releasing hormone levels result mainly in increased thyrotropin release and weakly in prolactin (PRL) release. Then, increased thyrotropin levels result in increased release of thyroid hormones. - indicates negative feedback, and + indicates positive feedback.
|
|
Copyright © 1999 by the Radiological Society of North America.
