Hyperintense Signal of the Posterior Pituitary on T1-weighted MR Images

Fujisawa, Ichiro; Asato, Reinin; Kawata, Mitsuhiro; Sano, Yutaka; Nakao, Kazuwa; Yamada, Tomoya; Imura, Hiroo; Naito, Yutaka; Hoshino, Ken; Noma, Satoshi

doi:10.1097/00004728-198905000-00001

Cited by 75 publications

(40 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We presumed that the release of AVP from neuroendocrine granules decreased AVP storage in the PL and decreased the SI ratio. Consistent with the results in this study of the correlation between plasma AVP concentrations and the SI ratio in normal Beagles, previous reports have shown reduction of the SI in the PL by oral administration of 2% NaCl [7] and a correlation between plasma AVP concentrations and SI in the PL under water deprivation conditions [14]. AVP is synthesized by magnocellular neurons in the paraventricular and supraoptic nuclei of the hypothalamus.…”

Section: Discussionsupporting

confidence: 92%

Relationship between Arginine Vasopressin and High Signal Intensity in the Pituitary Posterior Lobe on T1-Weighted MR Images in Dogs

Teshima

Hara

Masuda

et al. 2008

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. The posterior lobe of the pituitary gland (PL) normally shows characteristic high signal intensity (SI) on T1-weighted MR images (T1WI) in humans. The high SI is thought to represent storage of arginine vasopressin (AVP) in the PL. Normal dogs also show a high SI on T1WIs, but the origin is unclear. In the present study, we investigated whether the high SI in the PL on T1WIs in normal dogs is caused by AVP. We examined the SI in the PL on T1WIs, plasma AVP concentrations and plasma osmolality in normal dogs after excessive AVP secretion was induced by hypertonic saline overload. In addition, functional changes in the supraoptic nucleus and paraventricular nucleus of the hypothalamus under AVP secretion-stimulated conditions were examined immunohistologically. Under hypertonic saline overload, plasma osmolality and plasma AVP concentrations gradually increased, while the SI of the PL gradually decreased. This suggests that AVP secretion was stimulated by elevated osmolality. Moreover, there was a significant negative correlation between plasma AVP concentrations and the SI ratio of the PL. An immunohistochemical study of the hypothalamus nucleus revealed that AVP-immunopositive cells significantly increased in the hypertonic saline loaded dogs. We concluded that the high SI in the PL in T1WIs in normal dogs was caused by AVP stored at the site, and examination of the SI in the PL using MRI is useful for diagnosis of abnormal pituitary glands. KEY WORDS: arginine vasopressin, canine, MRI, pituitary, signal intensity.J. Vet. Med. Sci. 70 (7): [693][694][695][696][697][698][699] 2008 Magnetic Resonance Imaging (MRI) provides detailed anatomic information and is a useful diagnostic modality for a variety of diseases in human and veterinary clinical medicine. In particular, the utility of the MRI has been recognized in examinations of the central nervous system. It has been used not only to examine morphological changes in the hypothalamic-neurohypophyseal (HNS) system, but also to evaluate function by examining signal intensity in images [3]. For these reasons, the MRI is the first-choice modality for evaluation of HNS disease.The posterior lobe of the normal pituitary shows characteristically high signal intensity (SI) in T1-weighted images (T1WI) at two months after birth or later in humans, which differs from the anterior lobe of the pituitary [2,6,20]. In addition, the characteristically high SI is markedly decreased by depletion of arginine vasopressin (AVP) due to disorders such as central diabetes insipidus [8,[17][18][19]. On the basis of this change in T1WIs, the MRI is used for diagnosis of diabetes insipidus [16], ectopic posterior lobe [9,24] and depleted posterior lobe of the pituitary by continuous excessive AVP secretion due to diabetes mellitus [5]. Moreover, the presence and localization of the characteristically high SI (so-called "pituitary flush") can be helpful in diagnosing microadenoma in dogs with pituitary-dependent hyperadrenocorticism without obviously enlarged pituitaries [23]...

show abstract

Section: Discussionsupporting

confidence: 92%

Relationship between Arginine Vasopressin and High Signal Intensity in the Pituitary Posterior Lobe on T1-Weighted MR Images in Dogs

Teshima

Hara

Masuda

et al. 2008

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

show abstract

“…At the time of preparation of this report (10 months after the development of polyuria), the patient has been doing well without headache, . MRI in these patients also showed the absence of the hyperintense signal which is a characteristic feature of the normal neurohypophysis [6]. The present case was diagnosed as central DI based on the low excretion of AVP even under high-osmolar conditions.…”

supporting

confidence: 55%

An Elderly Patient with Transient Diabetes Insipidus Associated with Lymphocytic Infundibulo-Neurohypophysitis.

et al. 1999

View full text Add to dashboard Cite

Abstract.We present the eldest case ever reported of central diabetes insipidus (DI) associated with infundibuloneurohypophysitis.A 77-year old woman, who complained of recent development of excessive thirst, polyuria and polydipsia, was referred to our hospital. The daily urine volume was markedly increased to 6 L. DDAVP administration effectively reduced urine volume and increased urine osmolality.The loading test using high-osmolar sodium chloride showed impaired excretion of vasopressin discordant with plasma osmolar changes.The anterior pituitary function was normal. Pituitary magnetic resonance imaging (MRI) showed thickening of the pituitary stalk and a lack of high-intensity signal of the neurohypophysis on Ti-weighted images, suggestive of lymphocytic infundibulo-neurohypophysitis. The thickness of pituitary stalk on MRI improved 6 months later. DI was controlled with DDAVP for 40 days. This was followed by stabilization of the daily urine volume to less than 2.5 L without DDAVP.Our case is the eldest case of central DI associated with infundibulo-neurohypophysitis. The rapid remission of pituitary changes on MRI provides an insight that spontaneously partial remission of central DI may occur, resulting in transient polyuria and polydipsia.

show abstract

“…7 The HIS, thought to be related to the functional integrity of the HNA, disappears in patients with diabetes insipidus (DI).R. 9 In this report some characteristic MR findings of germinomas in the HNA are demonstrated.…”

mentioning

confidence: 75%

Magnetic resonance imaging of neurohypophyseal germinomas

Fujisawa

Asato

Okumura

et al. 1991

Cancer

Self Cite

View full text Add to dashboard Cite

The authors reviewed magnetic resonance (MR) images in seven cases of germinoma in the hypothalamoneurohypophyseal axis (HNA). The intrasellar portions were clearly identified in six germinomas. Two small germinomas of these six were located only in the neurohypophysis. The major parts of the four large germinomas were located below the optic chiasm, and the large intrasellar portions were demonstrated. The remaining one small germinoma was localized from the pituitary stalk to the third ventricular floor. These findings strongly suggest that the primary site of germinomas in the HNA is the neurohypophysis. In the four large germinomas, the tumor shape was similar to that of pituitary adenoma. The authors believe that age (limited to first three decades), symptoms (diabetes insipidus), MR findings absence of normal hyperintense signal of the posterior pituitary on T1‐weighted (T1W1) images, and homogeneous hypointensity to the pons on T1W1 images/isointensity on T2‐weighted images are important in differential diagnosis.

show abstract

Hyperintense Signal of the Posterior Pituitary on T1-weighted MR Images

Cited by 75 publications

References 0 publications

Relationship between Arginine Vasopressin and High Signal Intensity in the Pituitary Posterior Lobe on T1-Weighted MR Images in Dogs

Relationship between Arginine Vasopressin and High Signal Intensity in the Pituitary Posterior Lobe on T1-Weighted MR Images in Dogs

An Elderly Patient with Transient Diabetes Insipidus Associated with Lymphocytic Infundibulo-Neurohypophysitis.

Magnetic resonance imaging of neurohypophyseal germinomas

Contact Info

Product

Resources

About