Demonstration of the inferior intercavernous sinus is closely linked to the extent of pneumatization of the sphenoid sinus: useful information for the pituitary surgeon.

PURPOSE: To study the utility of T2-weighted MRI sequences in the identification of the inferior intercavernous sinus (IICS), a potential source of bleeding during transsphenoidal surgery of pituitary adenomas. METHODS: Pituitary sagittal T1W and coronal T2W MRI sequences were analyzed in 237 consecutive patients, after the exclusion of postoperative MRIs and those revealing an empty sella or a pituitary macroadenoma. Sphenoid sinus pneumatization was defined as incomplete (group 1) if it did not reach the nadir of the sella turcica, as complete (group 2) if it extended beyond the nadir of the sella or asymmetric (group 3), when only one side of the sinus was completely pneumatized. RESULTS: In Group 2 (70% of the patients), the IICS was rarely visualized on coronal T2W MRI (6/167 patients-3.6%), whereas in Group 1 it was identified in nearly all patients (55/57 patients - 96.5%, p < 0.001). In Group 3, the IICS was only visible above the non-pneumatized part of the sphenoid sinus. CONCLUSIONS: The IICS can be identified on coronal T2W images in patients with an incompletely pneumatized sphenoid sinus, but very rarely in patients with a totally pneumatized sinus. This information can help to increase awareness among pituitary surgeons of the need to potentially manage IICS bleeding during transsphenoidal surgery in patients with an incompletely pneumatized sphenoid sinus.

T2-weighted MRI signal intensity as a predictor of hormonal and tumoral responses to somatostatin receptor ligands in acromegaly: a perspective.

T2-weighted MRI signal intensity of GH-secreting pituitary adenomas is gaining recognition as a marker of disease characteristics and may be a predictor of response to treatment of acromegaly. Adenomas that are T2-hypointense are more common, are smaller and are less likely to invade the cavernous sinus compared to the T2-iso and hyperintense tumors. T2-hypointense tumors are also accompanied by higher IGF1 values at baseline. When presurgical somatostatin receptor ligand (SRL) therapy is administered, T2-hypointense adenomas have better hormonal responses and have greater tumor shrinkage. Adjuvant SRL therapy of patients with T2-hypointense tumors that are uncured by surgery is also associated with a better hormonal response. We review the studies that have dealt with the T2-weighted signal intensity of GH-secreting pituitary tumors and elaborate on the details and nuances of this promising avenue of research.

Intensity of prolactinoma on T2-weighted magnetic resonance imaging: towards another gender difference.

INTRODUCTION: Clinical presentations of prolactinomas are quite different between genders. In comparison with women's prolactinoma, those in men showed predominance of large tumors with high prolactin (PRL) levels. This preponderance could be attributed to a greater proliferative potential of the tumors. Differences in magnetic resonance imaging (MRI) signal at diagnosis have not been yet clearly evaluated. METHODS: We conduct a retrospective study comparing MRI signal intensity (SI) on T2-weighted images (T2-WI) between 41 men and 41 women to investigate whether or not men prolactinoma present specific features. RESULTS: In addition to the size of the adenoma and PRL levels (P < 0001), prolactinomas in men also exhibit differences from those in women in signal on T2-WI on MRI (P < 0001). Women's prolactinomas are mostly of high SI on T2-WI while men's prolactinomas exhibit a more heterogeneous pattern of SI on T2-WI. Prolactinomas presenting with low SI on T2-WI are almost exclusively encountered in men. CONCLUSIONS: Presence of T2-WI hypointensities in pituitary adenoma can be predictive of a different subtype of prolactinoma almost encountered in men and possibly translate the presence of spherical amyloid deposits, in agreement with the literature.

3D TOF MR angiography to depict pituitary bright spot and to detect posterior pituitary lobe cyst: Original description at 3T MR imaging.

PURPOSE: There is no detailed description of the pituitary bright spot (PBS) at 3T in the literature. This study assesses detection of PBS on axial source images of 3D TOF sequence at 3T, and reports cysts in this location for the first time. METHODS: We retrospectively studied 250 consecutive patients who underwent brain 3T MRI with high resolution 3D TOF angiogram and thin axial T2-weighted sequences. On the axial source images of the 3F TOF, we assessed the presence, location and shape of the PBS. A cyst was diagnosed within the PBS in cases with central sharply defined low-TOF signal intensity surrounded by a rim of hyperintense signal. High T2 signal intensity corresponding precisely with the low T1 signal was also necessary for the diagnosis of such cysts. Evolution of these cysts was assessed on follow-up MRI. RESULTS: PBS was depicted in 83% of patients. Prevalence was significantly higher in women than in men (89% vs 70%, P<0.01). Patients with PBS were significantly younger than those without (mean age 54.1 years vs 59.4 years, P<0.05). A cyst within the PBS was depicted in six patients (2.9%). Mean size was 1.9 mm. These cysts were asymptomatic and remained stable during follow-up. CONCLUSIONS: Axial source images of 3D TOF angiogram can be used to assess the posterior pituitary lobe as the PBS was detected in 83% of our cohort. When cysts are seen within, they may be considered incidental findings that remained stable at follow-up.

How often should we perform magnetic resonance imaging (MRI) for the follow-up of pituitary adenoma?

Magnetic resonance imaging (MRI) is the examination of choice for diagnosing and monitoring pituitary adenoma (also known as pituitary neuroendocrine tumor or PitNET), whether treated or not. However, repeating the examination too often (and sometimes unnecessarily) is costly, and worrying data on tissue accumulation (brain, bone, etc.) of gadolinium atoms dissociated from their carrier molecule (chelator) have led European authorities to ban contrast agents based on linear chelators of gadolinium, which are particularly susceptible to rapid dissociation, in favor of chemically more stable macrocyclic chelators. It is therefore important to determine the optimal frequency for pituitary MRI monitoring in order to safely assess the natural history or therapeutic response of pituitary adenomas. The aim of this article is to summarize the most recent data on optimal follow-up intervals depending on the type, size and location of the pituitary tumor and the clinical situation in general, in order to generate monitoring algorithms to guide clinicians.

A new prognostic clinicopathological classification of pituitary adenomas: a multicentric case-control study of 410 patients with 8 years post-operative follow-up.

Pituitary adenomas are currently classified by histological, immunocytochemical and numerous ultrastructural characteristics lacking unequivocal prognostic correlations. We investigated the prognostic value of a new clinicopathological classification with grades based on invasion and proliferation. This retrospective multicentric case-control study comprised 410 patients who had surgery for a pituitary tumour with long-term follow-up. Using pituitary magnetic resonance imaging for diagnosis of cavernous or sphenoid sinus invasion, immunocytochemistry, markers of the cell cycle (Ki-67, mitoses) and p53, tumours were classified according to size (micro, macro and giant), type (PRL, GH, FSH/LH, ACTH and TSH) and grade (grade 1a: non-invasive, 1b: non-invasive and proliferative, 2a: invasive, 2b: invasive and proliferative, and 3: metastatic). The association between patient status at 8-year follow-up and age, sex, and classification was evaluated by two multivariate analyses assessing disease- or recurrence/progression-free status. At 8 years after surgery, 195 patients were disease-free (controls) and 215 patients were not (cases). In 125 of the cases the tumours had recurred or progressed. Analyses of disease-free and recurrence/progression-free status revealed the significant prognostic value (p < 0.001; p < 0.05) of age, tumour type, and grade across all tumour types and for each tumour type. Invasive and proliferative tumours (grade 2b) had a poor prognosis with an increased probability of tumour persistence or progression of 25- or 12-fold, respectively, as compared to non-invasive tumours (grade 1a). This new, easy to use clinicopathological classification of pituitary endocrine tumours has demonstrated its prognostic worth by strongly predicting the probability of post-operative complete remission or tumour progression and so could help clinicians choose the best post-operative therapy.

Pituitary MRI in Cushing's disease - an update.

Pituitary MRI is essential in the diagnosis of ACTH-dependent Cushing's syndrome, but its results are inconsistent. The demonstration of a sellar image compatible with the diagnosis of corticotropinoma varies from 40% to 90%, depending on the centre where the imaging is performed. In fact, the expertise of the neuroradiologist, use of a Tesla 3.0 MRI and choice of sequences are fundamental. The T2 and 3D gradient echo sequences after gadolinium injection are the most informative and today allow the detection of macro- and microadenomas in almost all cases. The diagnosis of numerous picoadenomas (<3-4 mm) is more challenging. The 2D and 3D spin echo or delayed T1 SE or FLAIR sequences after gadolinium can be used as a complement or to confirm a suspicious image. Characterization of corticotropinomas remains problematic. However, the correct assessment of so-called incidentalomas by recognizing artifacts, anatomical variants and frequent Rathke's cleft cysts eliminates around 90% of the incidentalomas that mimic pituitary adenomas, as repetitively reported in the literature. For the time being, there is reason to believe that hybrid imaging combining PET and MRI such as 11C-methionine PET coregistered with volumetric MRI will solve the diagnosis of corticotropinomas in the near future.

Predictive Factors of Somatostatin Receptor Ligand Response in Acromegaly-A Prospective Study.

CONTEXT: Somatostatin receptor ligands (SRLs) are the cornerstone medical treatments for acromegaly; however, many patients remain unresponsive to SRLs. Well-established predictive markers of response are needed. OBJECTIVE: We aimed to explore the relationship between responsiveness to SRLs relative to somatostatin (SST)2A and 5 receptor expression, adenoma granularity, and T2-weighted magnetic resonance imaging (MRI) signal intensity (T2WSI). METHODS: We conducted a multicentric, prospective, observational cohort study, in France. Forty-nine naïve patients (ie, patients without preoperative SRL treatment) with active acromegaly following surgery were treated with octreotide (group 1; n = 47), or pasireotide if uncontrolled under first-generation SRLs (group 2; n = 9). Data were collected at baseline and months 3 and 6. Biochemical measurements, immunohistochemistry studies, and MRI readings were centralized. RESULTS: In group 1, IGF-I decrease from baseline to month 6 positively correlated with SST2A immunoreactive score (IRS), P = 0.01. Densely granulated/intermediate adenomas had a greater IGF-I and GH decrease under octreotide compared with sparsely granulated adenomas (P = 0.02 and P = 0.006, respectively), and expressed greater levels of SST2A (P < 0.001), coupled with lower levels of SST5 (P = 0.004). T2WSI changed between preoperative MRI and month 6 MRI in one-half of the patients. Finally, SST5 IRS was higher in preoperative hyperintense compared with preoperative hypointense adenomas (P = 0.04), and most sparsely granulated and most hyperintense adenomas expressed high SST5 levels. CONCLUSION: We prospectively confirm that SST2A and adenoma granularity are good predictors of response to octreotide. We propose the IRS for scoring system harmonization. MRI sequences must be optimized to be able to use the T2WSI as a predictor of treatment response.

Pituitary MRI Features in Acromegaly Resulting From Ectopic GHRH Secretion From a Neuroendocrine Tumor: Analysis of 30 Cases.

CONTEXT: Ectopic acromegaly is a consequence of rare neuroendocrine tumors (NETs) that secrete GHRH. This abnormal GHRH secretion drives GH and IGF-1 excess, with a clinical presentation similar to classical pituitary acromegaly. Identifying the underlying cause for the GH hypersecretion in the setting of ectopic GHRH excess is, however, essential for proper management both of acromegaly and the NET. Owing to the rarity of NETs, the imaging characteristics of the pituitary in ectopic acromegaly have not been analyzed in depth in a large series. OBJECTIVE: Characterize pituitary magnetic resonance imaging (MRI) features at baseline and after NET treatment in patients with ectopic acromegaly. DESIGN: Multicenter, international, retrospective. SETTING: Tertiary referral pituitary centers. PATIENTS: Thirty ectopic acromegaly patients having GHRH hypersecretion. INTERVENTION: None. MAIN OUTCOME MEASURE: MRI characteristics of pituitary gland, particularly T2-weighted signal. RESULTS: In 30 patients with ectopic GHRH-induced acromegaly, we found that most patients had hyperplastic pituitaries. Hyperplasia was usually moderate but was occasionally subtle, with only small volume increases compared with normal ranges for age and sex. T2-weighted signal was hypointense in most patients, especially in those with hyperplastic pituitaries. After treatment of the NET, pituitary size diminished and T2-weighted signal tended to normalize. CONCLUSIONS: This comprehensive study of pituitary MRI characteristics in ectopic acromegaly underlines the utility of performing T2-weighted sequences in the MRI evaluation of patients with acromegaly as an additional tool that can help to establish the correct diagnosis.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome.

Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.

Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis.

BACKGROUND: Carotid stenting is less invasive than endarterectomy, but it is unclear whether it is as safe in patients with symptomatic carotid-artery stenosis. METHODS: We conducted a multicenter, randomized, noninferiority trial to compare stenting with endarterectomy in patients with a symptomatic carotid stenosis of at least 60%. The primary end point was the incidence of any stroke or death within 30 days after treatment. RESULTS: The trial was stopped prematurely after the inclusion of 527 patients for reasons of both safety and futility. The 30-day incidence of any stroke or death was 3.9% after endarterectomy (95% confidence interval [CI], 2.0 to 7.2) and 9.6% after stenting (95% CI, 6.4 to 14.0); the relative risk of any stroke or death after stenting as compared with endarterectomy was 2.5 (95% CI, 1.2 to 5.1). The 30-day incidence of disabling stroke or death was 1.5% after endarterectomy (95% CI, 0.5 to 4.2) and 3.4% after stenting (95% CI, 1.7 to 6.7); the relative risk was 2.2 (95% CI, 0.7 to 7.2). At 6 months, the incidence of any stroke or death was 6.1% after endarterectomy and 11.7% after stenting (P=0.02). There were more major local complications after stenting and more systemic complications (mainly pulmonary) after endarterectomy, but the differences were not significant. Cranial-nerve injury was more common after endarterectomy than after stenting. CONCLUSIONS: In this study of patients with symptomatic carotid stenosis of 60% or more, the rates of death and stroke at 1 and 6 months were lower with endarterectomy than with stenting. (ClinicalTrials.gov number, NCT00190398 [ClinicalTrials.gov].).

AIP-mutated acromegaly resistant to first-generation somatostatin analogs: long-term control with pasireotide LAR in two patients.

Acromegaly is a rare disease due to chronic excess growth hormone (GH) and IGF-1. Aryl hydrocarbon receptor interacting protein (AIP) mutations are associated with an aggressive, inheritable form of acromegaly that responds poorly to SST2-specific somatostatin analogs (SSA). The role of pasireotide, an SSA with affinity for multiple SSTs, in patients with AIP mutations has not been reported. We studied two AIP mutation positive acromegaly patients with early-onset, invasive macroadenomas and inoperable residues after neurosurgery. Patient 1 came from a FIPA kindred and had uncontrolled GH/IGF-1 throughout 10 years of octreotide/lanreotide treatment. When switched to pasireotide LAR, he rapidly experienced hormonal control which was associated with marked regression of his tumor residue. Pasireotide LAR was stopped after >10 years due to low IGF-1 and he maintained hormonal control without tumor regrowth for >18 months off pasireotide LAR. Patient 2 had a pituitary adenoma diagnosed when aged 17 that was not cured by surgery. Chronic pasireotide LAR therapy produced hormonal control and marked tumor shrinkage but control was lost when switched to octreotide. Tumor immunohistochemistry showed absent AIP and SST2 staining and positive SST5. Her AIP mutation positive sister developed a 2.5 cm follicular thyroid carcinoma aged 21 with tumoral loss of heterozygosity at the AIP locus and absent AIP staining. Patients 1 and 2 required multi-modal therapy to control diabetes. On stopping pasireotide LAR after >10 years of treatment, Patient 1's glucose metabolism returned to baseline levels. Long-term pasireotide LAR therapy can be beneficial in some AIP mutation positive acromegaly patients that are resistant to first-generation SSA.

Assessment of the course and division patterns of the middle cerebral artery M1 segment. Transcranial power doppler compared with 3D time-of-flight magnetic resonance angiography at 3 T.

BACKGROUND AND PURPOSE: The present study was undertaken to assess the ability of bedside transcranial color-coded sonography (TCCS) to define the course and the patterns of the division of the middle cerebral artery (MCA) M1 segment compared with 3D time-of-flight magnetic resonance angiography (MRA) at 3 T. METHODS: Because MRA is considered as a reliable noninvasive technique to depict the normal anatomy of the intracranial artery, we prospectively defined the course and the patterns of division of 100 MCA M1 segments using bedside TCCS and compared the results with MRA findings. RESULTS: In 68/85 cases (80%), the sonographer was able to define the division of the M1 segment, and classified these as bipode for 50/68 (73.5%), monopode for 16/68 (23.5%) and tripode for 2/68 (3%). A comparison of the TCCS and MRA findings showed a perfect correlation (100%) for the course of the M1 segment. As for the type of division, the correlation was good in 45/68 of cases (67%). TCCS had a sensitivity of 78%, a specificity of 67%, a positive predictive value of 87% and a negative predictive value of 52%, when used to determine whether the division was bipode or not. CONCLUSIONS: Our results show that bedside TCCS can now provide anatomical information on the M1 segment of the MCA.

Value of intravascular ultrasound imaging in following up patients with replacement of the ascending aorta for acute type A aortic dissection.

BACKGROUND: The value of intravascular ultrasound (IVUS) imaging in patients with replacement of the ascending aorta for acute type A aortic dissection (AD) is unknown. The purpose of this study was to assess the potential use of IVUS imaging in this setting. METHODS: From September 2002 to July 2005, IVUS imaging with a 9 MHz probe was performed in a series of 16 consecutive patients with suspected or established AD. This study focused on 5 of them with replacement of the ascending aorta for acute type A AD. Among these 5 patients, other imaging modalities including aortography, spiral computed tomography, magnetic resonance imaging and transesophageal echocardiography were performed in 5, 3, 3 and 1 patients, respectively. RESULTS: There were no complications related to IVUS imaging. For the replaced graft, as other imaging modalities, IVUS could identify all 5 grafts, the proximal and the distal anastomoses, and the ostia of the reimplanted coronary arteries. In 2 cases, IVUS detected 2 peri-graft pseudo-aneurysms (1 per case), which were also detected by magnetic resonance imaging but omitted by aortography. For the residual dissection, IVUS had similar findings as other imaging modalities in detecting the patency (5/5), the longitudinal and the circumferential extent, the thrombus (4/5), the recurrent dissection (1/5) and an aneurysm distal to the graft (5 in 4 patients). However, it detected more intimal tears and side branch involvements than other imaging modalities (15 vs 10 and 3 vs 1, respectively). CONCLUSIONS: In following-up patients with replacement of the ascending aorta for acute type A AD, IVUS imaging can provide complete information of the replaced graft and the residual dissection. So, IVUS imaging may be considered when the four current frequently used imaging modalities can not supply sufficient information or there are some discrepancies between them.

Adipsic diabetes insipidus revealing a bifocal intracranial germinoma.

Adipsic diabetes insipidus is a rare complication of intracranial tumors in which impaired antidiuretic hormone secretion is associated with the loss of thirst sensation. Here, we present the case of a patient with bifocal intracranial germinoma, diagnosed due to symptoms mainly caused by adipsic diabetes insipidus. This is, to our knowledge, the first case of adipsic diabetes insipidus revealing an intracranial germinoma reported in the literature. We describe the diagnostic procedures and the three-year follow-up of this patient. Management of intracranial germ-cell tumors is made complex by the wide range of histological features. Although germinomas have a generally better prognosis than most nongerminomatous tumors, they can have severe or even life-threatening presentations. Adipsic diabetes insipidus is one such severe presentation and its rarity can make it difficult to recognize and manage. Awareness of this potential entity is therefore important for clinical practice.

T1 signal hyperintensity in the sellar region: spectrum of findings.

T1 signal hyperintensity is a common finding at magnetic resonance imaging of the sellar region. However, this signal intensity pattern has different sources, and its significance depends on the clinical context. Normal variations in sellar T1 signal hyperintensity are related to vasopressin storage in the neurohypophysis, the presence of bone marrow in normal and variant anatomic structures, hyperactive hormone secretion in the anterior pituitary lobe (eg, in newborns and pregnant or lactating women), and flow artifacts and magnetic susceptibility effects. Pathologic variations in T1 signal hyperintensity may be related to clotting of blood (in hemorrhagic pituitary adenoma, pituitary apoplexy, Sheehan syndrome, or thrombosed aneurysm) or the presence of a high concentration of protein (Rathke cleft cyst, craniopharyngioma, or mucocele), fat (lipoma, dermoid cyst, lipomatous meningioma), calcification (craniopharyngioma, chondroma, chordoma), or a paramagnetic substance (manganese, melanin). After treatment, T1 signal hyperintensity may result from the presence of materials used for surgical packing (gelatin sponge, fat); from compression of the cavernous sinus and reduction of the venous flow, caused by overpacking of the operative bed; or from hormone hypersecretion by a remnant of normal tissue in the anterior lobe of the pituitary gland.

Magnetic Resonance Imaging of Pituitary Tumors.

Magnetic Resonance Imaging (MRI) is currently considered a major keystone of the diagnosis of diseases of the hypothalamic-hypophyseal region. However, the relatively small size of the pituitary gland, its location deep at the skull base and the numerous physiological variants present in this area impede the precise assessment of the anatomical structures and, particularly, of the pituitary gland itself. The diagnosis of the often tiny lesions of this region--such as pituitary microadenomas--is then difficult if the MRI technology is not optimized and if potential artifacts and traps are not recognized. Advanced MRI technology can not only depict small lesions with greater reliability, but also help in the differential diagnosis of large tumors. In these, defining the presence or absence of invasion is a particularly important task. This review describes and illustrates the radiological diagnosis of the different tumors of the sellar region, from the common prolactinomas, nonfunctioning adenomas and Rathke's cleft cysts, to the less frequent and more difficult to detect corticotroph pituitary adenomas in Cushing's disease, and other neoplastic and nonneoplastic entities. Finally, some hints are given to facilitate the differential diagnosis of sellar lesions.