Diabetes insipidus can be caused by lymphocytic infundibuloneurohypophysitis, which can be detected by MRI. The natural course of the disorder is self-limited.

Magnetic resonance (MR) imaging was performed in ten patients with pituitary stalk transection who had idiopathic pituitary dwarfism. Contiguous sagittal T1-weighted images were obtained in all cases, and, in some, axial or coronal images were taken for further evaluation. On MR images, normal anterior and posterior lobes of the pituitary gland can be clearly differentiated because the posterior lobe has a characteristic high intensity on T1-weighted images. In the ten patients, the high-intensity posterior lobe was not seen, but a similar high signal intensity was observed at the proximal stump in seven patients. This high-intensity area is the newly formed ectopic posterior lobe, which secretes antidiuretic hormone just as the posterior lobe would. When the ectopic lobe completely compensates for the impaired posterior lobe, endocrinologic data indicate normal posterior lobe function. However, MR imaging can reveal the transection of the pituitary stalk and formation of the ectopic lobe.

The potential of magnetic resonance (MR) imaging in differentiation of adenomyosis from leiomyoma was evaluated in 93 patients who had a palpable enlarged uterus that was suspect for leiomyoma or adenomyosis. In all cases, MR images were correlated with surgical/pathologic findings. Pathologic findings showed that 71 enlarged uteri were due to leiomyoma, including one leiomyosarcoma, and 16 were due to adenomyosis. The other six patients were shown to have an enlarged uterus attributable to simultaneous involvement of both lesions. On T2-weighted images, adenomyosis appeared as an ill-defined, relatively homogeneous low-signal-intensity area embedded with sparse high-intensity spots. In contrast, leiomyomas were well-circumscribed masses with a spectrum of signal intensity. The cause of uterine enlargement was correctly diagnosed with MR images in 92 of the 93 cases. It is concluded that MR imaging is highly accurate in helping to distinguish between adenomyosis and leiomyoma in cases of enlarged uterus.

Abstract. Inflammatory lesions of the pituitary gland are rarely encountered. Recently, the concept of immunoglobulin G4 (IgG4)-related systemic disease was proposed in Japan, and more than 20 cases have been reported as possibly associated with infundibulo-hypophysitis since 2000. We herein review such case reports in the published literature and in the abstracts of scientific meetings. Almost all cases involved middle-aged to elderly men presenting with various degrees of hypopituitarism and diabetes insipidus and demonstrating a thickened pituitary stalk and/or pituitary mass. These structures shrank remarkably in response to glucocorticoid therapy, even in a lower dose range similar to that prescribed as a replacement for adrenocortical insufficiency. Some of the anterior pituitary insufficiencies were also resolved by glucocorticoid administration. The presence of IgG4-related systemic disease and an elevated serum IgG4 level before glucocorticoid therapy were the main clues to a correct diagnosis of IgG4-related infundibulo-hypophysitis. Autoimmunity is suggested but not yet established to play a role in the pathogenesis for IgG4-related systemic disease. The fact that hypertrophic pachymeningitis and para-sinusitis accompanied some cases suggested that both sellar and parasellar structures are involved in the chronic inflammation. We therefore classify this disorder not as a variant form of primary autoimmune hypophysitis but as a secondary form of infundibulo-hypophysitis associated with IgG4-related systemic disease.

We compared 1.5 T magnetic resonance (MR) image findings with hypothalamic-pituitary function in 11 patients with idiopathic pituitary dwarfism, each of whom had a history of perinatal abnormalities, and 1 patient with posttraumatic pituitary dwarfism. MR imaging revealed transection of the pituitary stalk in all patients and the formation of an ectopic posterior lobe at the proximal stump in 9 patients, none of whom had polydipsia or polyuria. Three patients without an ectopic posterior lobe had diabetes insipidus. The 5 patients who had small pituitary glands (less than 2 mm in height) had hypothyroidism with low serum TSH concentrations and low serum cortisol responses to insulin-induced hypoglycemia; however, 7 patients with normal-sized pituitary glands had normal thyroid and adrenal function. The serum GH response to GHRH did not correlate with the size of the pituitary gland. The patients with small pituitary glands had delayed or prolonged serum TSH responses to TRH and impaired serum LH and FSH responses to GnRH; 4 of the patients with normal-sized pituitary glands had normal serum TSH, LH, and FSH responses. Only 2 patients had high basal serum PRL concentrations. The endocrinological data suggest that reestablishment of the hypothalamo-hypophyseal portal circulation, which cannot be seen by MR imaging, may occur. We suggest that the primary cause of idiopathic pituitary dwarfism in many patients is injury to the pituitary stalk at birth.

Demonstration and staging of carcinoma of the cervix with magnetic resonance (MR) imaging was evaluated prospectively in 67 patients with histologically proven lesions. Findings were correlated with surgical/pathologic results obtained within 2 weeks. MR imaging had an accuracy of 95% in demonstrating invasive disease (stage IB or higher). It was capable of depicting the location and extent of tumor invasion of cervical stroma and helped detect tumor beneath relatively normal epithelium or within the endocervical canal that had not been detected by means of colposcopic biopsy. The overall accuracy of MR imaging in staging carcinoma of the cervix was 76%, and in demonstrating parametrial status, the overall accuracy was 89%. In 39 patients with proven invasive disease, the accuracy in demonstrating parametrial status was 82%. In 13 of these 39 patients the low-signal-intensity stromal ring of the cervix on MR images was completely preserved and there were no false-positive results. MR imaging is a highly promising method for directly demonstrating and staging carcinoma of the cervix and seems to be capable of providing answers to crucial questions regarding mode of therapy.

No abstract

Magnetic resonance (MR) imaging characteristics of adenomyosis were studied in eight women (aged 37-49 years) who underwent hysterectomy, and detailed radiologic/pathologic correlation was conducted in all cases. Adenomyosis produced diffuse and smooth uterine enlargement. The extent of the lesion was clearly identified on images obtained with long repetition time and long echo time; a diffuse, low-intensity area accompanied by tiny high-intensity spots was seen subjacent to the endometrium. The area appeared as a localized or diffuse thickening of the junctional zone because it was often isointense with this zone. Pathologic examination confirmed that the extent of adenomyosis correlated well with the low-intensity region on MR images and that both hemorrhagic areas and nonbleeding endometrial tissue corresponded to the high-intensity spots. The lesion consisted of distorted and compacted smooth muscle cells, but microscopic studies failed to explain the definitive difference in intensity between areas of adenomyosis and myometrium.