An Infundibular Unidentified Object (IUO): a new pituitary stalk marker?

PURPOSE: Measurement of the pituitary stalk (PS) diameter does not always solve the issue of minimal PS thickening. A previously undescribed image is found at the infundibular level on high resolution thin section T2W MRI in a large number of normal individuals. We speculate that this image-whose exact origin is still unknown-may serve as a marker of the normal infundibulum. METHODS: In the last 6 months, 350 consecutive adult patients suspected of sellar pathology or controlled after medical or surgical treatment prospectively underwent a pituitary MRI including a sagittal T2W high resolution sequence. One hundred twelwe patients presenting a pituitary mass with suprasellar extension or those whose PS was not entirely visible were excluded. RESULTS: A short focal annular T2 hypointense thickening of the wall of the infundibular recess of the third ventricle, more pronounced anteriorly was found in 151/238 patients. Additionally, a more or less tiny ventral extension was demonstrated on sagittal T2W sequence in 105/151 patients. These images were not identified on T1W or on T1W gadolinium enhanced sequences. The ring-like infundibular thickening and/or its ventral extension were not identified in 87/238 patients; in 43/87 of these patients the PS was found severely stretched mainly in case of primary or secondary empty sella. If patients with empty sella were excluded, our finding was observed in 194/238 cases, i.e. in 82%. CONCLUSIONS: A detailed appearance of the PS on T2W MRI is described for the first time. A previously unreported T2W hypointense annular focal image prolonged by a tiny spicular or nodular ventral bud is found at the lower part of the infundibulum in a majority of normal patients, but not if the PS is stretched such as in empty sella. This image has to be recognized as a normal anatomical landmark. The possible origin of this image is discussed but not totally elucidated. An ongoing research will demonstrate or not if this image may serve as a marker to improve the early diagnosis of PS lesions.

Neuroimaging of aggressive pituitary tumors.

Aggresssive pituitary tumors are defined as radiologically invasive, exhibiting a rapid growth and a poor response to the medical and surgical treatment options. The role of magnetic resonance imaging (MRI) is fundamental to assess tumor aggressiveness before surgical exploration. Distinction between cavernous sinus invasion and cavernous sinus compression is often challenging and cannot be solved always by using the Knosp criteria. Ideally, T2W images demonstrating the ruptured internal dural wall of cavernous sinus is the ultimate proof of cavernous sinus invasion. Subtle tumor volume increase in a short time can be shown when sequential MR images are rigorously replicable. A microcystic pattern observed on T2W images frequently reflects a potentially aggressive tumor as observed in silent corticotroph pituitary adenomas.

IgG4 hypophysitis: Diagnosis and management.

IgG4-related hypophysitis is a rare disease, due to a lymphoplasmocytic IgG4 positive infiltration of the pituitary. Literature data are scarce, even though the description of cases has drastically increased over the last years. The aim of this review is to better characterize the natural history, the diagnosis and the management of IgG4-related hypophysitis, based on a clinical case, an exhaustive Pubmed research, and a reappraisal of the criteria for diagnosis. We will specifically focus on the differences with other etiologies of hypophysitis, in the aim of improving the diagnostic procedures for all the physicians who could have to take care of such patients.

MRI follow-up is unnecessary in patients with macroprolactinomas and long-term normal prolactin levels on dopamine agonist treatment.

OBJECTIVE: Both antitumor and antisecretory efficacies of dopamine agonists (DA) make them the first-line treatment of macroprolactinomas. However, there is no guideline for MRI follow-up once prolactin is controlled. The aim of our study was to determine whether a regular MRI follow-up was necessary in patients with long-term normal prolactin levels under DA. PATIENTS AND METHODS: We conducted a retrospective multicenter study (Marseille, Paris La Pitie Salpetriere and Nancy, France; Liege, Belgium) including patients with macroprolactinomas (largest diameter: >10 mm and baseline prolactin level: >100 ng/mL) treated by dopamine agonists, and regularly followed (pituitary MRI and prolactin levels) during at least 48 months once normal prolactin level was obtained. RESULTS: In total, 115 patients were included (63 men and 52 women; mean age at diagnosis: 36.3 years). Mean baseline prolactin level was 2224 ± 6839 ng/mL. No significant increase of tumor volume was observed during the follow-up. Of the 21 patients (18%) who presented asymptomatic hemorrhagic changes of the macroprolactinoma on MRI, 2 had a tumor increase (2 and 7 mm in the largest size). Both were treated by cabergoline (1 mg/week) with normal prolactin levels obtained for 6 and 24 months. For both patients, no further growth was observed on MRI during follow-up at the same dose of cabergoline. CONCLUSION: No significant increase of tumor size was observed in our patients with controlled prolactin levels on DA. MRI follow-up thus appears unnecessary in patients with biologically controlled macroprolactinomas.

[Diagnostic significance of T2W hypointensity of the sella]. / Valeur diagnostique d'un hyposignal T2 de la région sellaire.

Normal anatomical structures and lesions characterized by low T2W signal intensity are reviewed in this pictorial essay. The purpose is to demonstrate how evaluation of the appearance, shape and exact anatomical location of the T2W hypointense sellar region structure, correlated with its T1W signal intensity, can based on the clinical context lead to an appropriate differential diagnosis.

[Balloon assisted kyphoplasty: new technique for treatment of vertebral compression fractures]. / La kyphoplastie par ballonnets: nouvelle technique dans le traitement percutané des tassements vertébraux.

Balloon assisted kyphoplasty and vertebroplasty are minimally invasive procedures with established value in the management of osteoporotic and neoplastic vertebral compression fractures. Kyphoplasty, a variation of vertebroplasty, is a technique with indications and therapeutic particularities that require validation.

Etiological diagnosis of hyperprolactinemia.

There are numerous etiologies of hyperprolactinemia, a common reason for consultation. Diagnostic measures must be capable of identifying the tumors, the most frequent of which are prolactin adenomas. Hypothalamic-pituitary MRI is the reference morphological examination. In clinical practice, it is usually performed very early, following the discovery of increased plasma concentrations of PRL. This approach is warranted for marked increase in PRL in the absence of drugs with hyperprolactinemic effects (>10 x upper limit of normal) since a diagnosis of PRL adenoma is extremely likely under such circumstances. When hyperprolactinemia is moderate, which is the most common finding in practice, all etiologies are possible in theory and it is important to follow a rational diagnostic plan (history-taking to identify use of any drugs with hyperprolactinemic effects paying attention to renal and hepatic history, investigation for endocrine diseases occasionally associated with hyperprolactinemia such as hypothyroidism or polycystic ovary syndrome (PCOS), confirmation of hyperprolactinemia by a second assay when the initial level is less than five times the upper normal limit, pregnancy testing for women of childbearing age) in order to rule out all non-tumoral causes of hyperprolactinemia before proceeding with imaging. Absence of any consequences of hyperprolactinemia on gonadic function or the existence of a concomitant disease that could account for the clinical signs, demonstration of wide variations in PRL from one assay to another in a single patient could prompt screening for macroprolactinemia before MRI is ordered. Macroprolactinoma could also occur in the case of normal or doubtful MRI or discrepancy in response to medical or surgical treatment. T1- and T2-weighted coronal sections (with or without T1 after gadolinium injection) are generally sufficient for diagnosis of microprolactinoma. Dynamic tests may be useful if MRI is normal or unclear. Gadolinium injection with sagittal and axial sections is essential for examination of large lesions. In this case, when the increase of PRL is moderate (<150 mg/ml), a non-lactotropic lesion may be suspected without misdiagnosing a hook effect. Careful analysis of the images allows differentiation between tumoral lesions and pituitary hyperplasia.

Bilateral Persistent Pharyngo-Stapedial Arteries Revealed during Evaluation of a Carotid-Cavernous Fistula. 3 Tesla MR Angiographic Aspects.

SUMMARY: A 33-year-old woman was evaluated for a right carotid-cavernous fistula revealed by a proptosis and chemosis of the right eye. The initial angiogram showed a left persistent pharyngo- stapedial artery (Ph-SA). A temporal bone CT suggested bilateral pharyngo-stapedial artery persistence. The right Ph-SA was not opacified in the first angiogram because of the high degree of shunting in the fistula. Four months later the patient was admitted for treatment of the carotid-cavernous fistula. In the meantime, the fistula had altered, with spontaneous thrombosis of the ophthalmic vein, and decrease of the vascular steal, explaining that the right Ph-SA was clearly visible on the angiogram performed during the procedure. The carotid-cavernous fistula was completely occluded with five detachable coils. The followup included 3 Tesla MR angiography that showed complete closure of the fistula with preservation of the right ICA and bilateral persistent pharyngo-stapedial arteries.

[Tinnitus and stenosis of the cavernous internal carotid artery]. / Acouphènes et sténose de l'artère carotide interne intracaverneuse.

We report a case of isolated unilateral pulsatile tinnitus. Cerebral angiography showed a right intra-cranial internal carotid artery stenosis. Treatment by dilatation and stenting resulted in symptom resolution.

[MRI of the pituitary gland: indications and results in gynaecology and in obstetrics]. / L'IRM hypophysaire: indications et résultats en gynécologie et en obstétrique.

MRI is the sole radiological examination to be obtained if abnormal menses, galactorrhea or anovulation evokes the diagnosis of prolactinoma. Nevertheless, iatrogenic hyperprolactinemia or presence of big prolactin has to be ruled out before MRI is asked for. MRI of the pituitary gland must be technically optimal; analysis of the images has to be directed by clinical and biological data.

The dural tail sign--beyond meningioma.

There have been somewhat conflicting reports published about the significance of linear meningeal thickening and enhancement adjacent to peripherally located cranial mass lesions on contrast-enhanced magnetic resonance (MR) images. Most of the authors consider this so-called "dural tail sign" or "flare sign" almost specific for meningioma. This review illustrates the MR imaging findings of a wide spectrum of disorders that show this dural sign. Causes include other extra-axial lesions and also peripherally located intra-axial lesions such as neuromas, chloromas, metastases, lymphoma, gliomas, pituitary diseases, granulomatous disorders, and also cerebral Erdheim-Chester disease. The dural tail sign is not specific to a particular pathological process. Nevertheless, useful conclusions can be drawn from the morphology of the lesion, its enhancement pattern, and its solitary or multifocal presentation. The final diagnosis must be based on cerebrospinal fluid studies or histological studies after biopsy.

[Imaging of the extracranial carotid arteries: when, how and why?]. / Quand, comment et pourquoi réaliser une imagerie des carotides extracrâniennes?

The indications for treating carotid artery stenosis are related to the symptomatic nature of the lesion and the degree of stenosis. Duplex sonography is adequate for screening. While some groups believe that Duplex US alone or in combination with transcranial Doppler imaging may be sufficient for presurgical evaluation, it often is recommended to complete the evaluation with either MRA or CTA. Both techniques are advantageous since they allow evaluation of the cervical and intracranial arteries as well as cerebral parenchyma hence providing valuable information prior to definitive management. Catheter angiography remains indicated in patients with multi-vessel disease and ischemic cardiomyopathy, when results at non-invasive evaluation are discordant or in an emergency setting. Duplex US is used for routine follow-up of non-surgical lesions and after endarterectomy. Transcranial Doppler as well as advances in MRA and CTA techniques will be reviewed. Even though the treatment of atherosclerotic carotid artery stenoses remains primarily surgical, specific considerations related to angioplasty will be reviewed. Finally, diseases of the intracranial carotid artery and non-atherosclerotic diseases (dissection...) will also be discussed.