Marcel Maya

Pituitary Magnetic Resonance Imaging for Sellar and Parasellar Masses: Ten-Year Experience in 2598 Patients

CONTEXT Sellar and parasellar masses present with overlapping clinical and radiological features ranging from asymptomatic incidental presentations and hormonal effects to compressive local mass effects. Pituitary masses are diagnosed with increased frequency with magnetic resonance imaging (MRI) advancements and availability, but indications and diagnostic outcomes of MRI screening for sellar lesions are not defined. Although pituitary adenomas are the most frequently encountered sellar mass lesions, other etiologies should be considered in the differential diagnosis of a sellar mass. SETTING The study was conducted at a tertiary pituitary center. PATIENTS This study was a retrospective review of 2598 subjects undergoing at least one pituitary MRI scan from 1999 to 2009. MAIN OUTCOME MEASURE Prevalence and diagnosis of specific sellar and parasellar masses as screened by pituitary MRI. RESULTS The most common indications for pituitary imaging, excluding known mass follow-up, were for evaluation of hyperprolactinemia or hypogonadism. A normal pituitary gland was reported in 47% of subjects undergoing pituitary MRI. The most common pituitary adenomas initially identified by MRI included prolactinoma (40%), nonfunctioning adenoma (37%), and GH adenoma (13%). Nonadenomatous sellar masses accounted for 18% of visible lesions, of which the most common were Rathkes cleft cyst (19%), craniopharyngioma (15%), and meningioma (15%). Metastases accounted for 5% of nonpituitary lesions and breast cancer was the most common primary source. CONCLUSIONS Half of all pituitary MRI scans performed in a large patient population yielded no visible lesion. Nonadenomatous pituitary lesions should be considered in the diagnosis of sellar masses observed on MRI, and a high clinical suspicion is required to exclude the presence of a nonfunctioning pituitary adenoma.

Cranial nerve XII: the hypoglossal nerve.

The hypoglossal nerve, cranial nerve XII, is the motor supply of the tongue. An understanding of the intracranial and extracranial components is fundamental in the evaluation of hypoglossal pathology. The following discussion of the evaluation of the hypoglossal nerve will involve the embryology, anatomy, clinical basis, and imaging techniques with pathologic correlations.

Spontaneous retroclival hematoma in pituitary apoplexy: case series

OBJECT Pituitary apoplexy is a rare and potentially life-threatening disorder that is most commonly characterized by a combination of sudden headache, visual disturbance, and hypothalamic/hormonal dysfunction. In many cases, there is hemorrhagic infarction of an underlying pituitary adenoma. The resulting clinical symptoms are due to compression of the remaining pituitary, cavernous sinuses, or cranial nerves. However, there are only 2 case reports in the literature describing spontaneous retroclival expansion of hemorrhage secondary to pituitary apoplexy. Ten cases of this entity with a review of the literature are presented here. METHODS This is a single-institution retrospective review of 2598 patients with sellar and parasellar masses during the 10-year period between 1999 and 2009. The pituitary and brain MRI and MRI studies were reviewed by 2 neuroradiologists for evidence of apoplexy, with particular attention given to retroclival extension. RESULTS Eighteen patients (13 men and 5 women; mean age 54 years) were identified with presenting symptoms of sudden onset of headache and ophthalmoplegia, and laboratory findings consistent with pituitary apoplexy. Ten of these patients (8 men and 2 women; mean age 55 years) had imaging findings consistent with retroclival hematoma. CONCLUSIONS Retroclival hemorrhage was seen in the majority of cases of pituitary apoplexy (56%), suggesting that it is more common than previously thought.

Anti-NMDA encephalitis: an uncommon, autoimmune mediated form of encephalitis.

We report an interesting case of a 19 year old female with findings on MRI suggestive of viral encephalitis. An extensive workup was negative for infectious causes and she was subsequently diagnosed with anti-NMDA encephalitis. Anti-NMDA encephalitis is a highly lethal but treatable form of autoimmune encephalitis that has recently been characterized. It is frequently found in young women and associated with an underlying teratoma. Although rare, this diagnosis should be considered in young females for whom a rapid onset of encephalitis cannot be explained by more common causes.

Differentiation of Benign Angiomatous and Microcystic Meningiomas with Extensive Peritumoral Edema from High Grade Meningiomas with Aid of Diffusion Weighted MRI

Objective. To determine whether angiomatous and microcystic meningiomas which mimic high grade meningiomas based on extent of peritumoral edema can be reliably differentiated as low grade tumors using normalized apparent diffusion coefficient (ADC) values. Methods. Preoperative magnetic resonance imaging (MRI) of seventy patients with meningiomas was reviewed. Morphologically, the tumors were divided into 3 groups. Group 1 contained 12 pure microcystic, 3 pure angiomatoid and 7 mixed angiomatoid and microcystic tumors. Group 2 included World Health Organization (WHO) grade II and WHO grade III tumors, of which 28 were atypical and 9 were anaplastic meningiomas. Group 3 included WHO grade I tumors of morphology different than angiomatoid and microcystic. Peritumoral edema, normalized ADC, and cerebral blood volume (CBV) were obtained for all meningiomas. Results. Edema index of tumors in group 1 and group 2 was significantly higher than in group 3. Normalized ADC value in group 1 was higher than in group 2, but not statistically significant between groups 1 and 3. CBV values showed no significant group differences. Conclusion. A combination of peritumoral edema index and normalized ADC value is a novel approach to preoperative differentiation between true aggressive meningiomas and mimickers such as angiomatous and microcystic meningiomas.

Quantitative chemical exchange saturation transfer MRI of intervertebral disc in a porcine model.

Previous studies have associated low pH in intervertebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo.

Spontaneous thrombosis of neonatal vein of Galen malformation.

Vein of Galen malformations are rare congenital intracranial vascular malformations. Based on reports in the literature, spontaneous thrombosis or regression of these lesions is rare. Patients have variable outcomes from an asymptomatic course to death. The reasons behind spontaneous thrombosis are not entirely understood. Here the authors present a case of an infant diagnosed with a vein of Galen malformation in utero that subsequently went on to thrombose or regress. A review of the published cases on this phenomenon and the potential causality are discussed.

Angioinvasive Aspergillus-associated Stroke in an Immunocompetent Host Following Cardiac Surgery and ECMO

Introduction: Invasive cerebral aspergillosis is an uncommon cause of stroke among immunocompetent patients and has not been reported in association with cardiac surgery or extracorporeal membrane oxygenation (ECMO). We report the case of an immunocompetent host who developed aspergillus-associated stroke following coronary artery bypass graft (CABG) and ECMO. Case Report: A 59-year-old woman developed cardiogenic shock after 3-vessel-CABG requiring intra-aortic balloon pump placement and subsequent veno-arterial ECMO. Noncontrast computed tomography of the brain was suggestive of multiple bihemispheric ischemic infarcts. Postmortem pathologic analysis revealed aspergillus-associated inflammation of blood vessels and ischemic and petechial hemorrhagic strokes in the affected territories. Discussion and Conclusions: Ischemic infarcts in the setting of CABG or ECMO are often presumed to be thromboembolic from the heart or device, related to underlying hemodynamic instability, or due to a clinically apparent systemic infection such as endocarditis. This report suggests that invasive cerebral aspergillosis should be considered in seemingly immunocompetent patients following CABG or ECMO. The mechanism is unclear, but may be related to systemic inflammatory dysregulation resulting in increased susceptibility to uncommon pathogens.

Prospective Single-Site Experience with Radiofrequency-Targeted Vertebral Augmentation for Osteoporotic Vertebral Compression Fracture

Vertebral augmentation procedures are widely used to treat osteoporotic vertebral compression fractures (VCFs). We report our initial experience with radiofrequency-targeted vertebral augmentation (RF-TVA) in 20 patients aged 50 to 90 years with single-level, symptomatic osteoporotic VCF between T10 and L5, back pain severity > 4 on a 0 to 10 scale, Oswestry Disability Index ≥ 21%, 20% to 90% vertebral height loss compared to adjacent vertebral body, and fracture age < 6 months. After treatment, patients were followed through hospital discharge and returned for visits after 1 week, 1 month, and 3 months. Back pain severity improved 66% (P < 0.001), from 7.9 (95% CI: 7.1 to 8.6) at pretreatment to 2.7 (95% CI: 1.5 to 4.0) at 3 months. Back function improved 46% (P < 0.001), from 74 (95% CI: 69% to 79%) at pretreatment to 40 (95% CI: 33% to 47%) at 3 months. The percentage of patients regularly consuming pain medication was 70% at pretreatment and only 21% at 3 months. No adverse events related to the device or procedure were reported. RF-TVA reduces back pain severity, improves back function, and reduces pain medication requirements with no observed complications in patients with osteoporotic VCF.

Chapter 20 – Pituitary Imaging

Publisher Summary Imaging of the sella turcica and of the pituitary received tremendous attention almost from the inception of radiography. It was soon recognized that changes in and around the sella turcica could reflect numerous intracranial conditions, not solely those of the pituitary itself. Further, the importance of the pituitary glands intricate function spurred interest in the evaluation of the sella turcica as a window to the gland itself. Plain radiography was the first and, for many decades, the only technique applicable to imaging of the sella turcica. Accordingly, there is a remarkably extensive literature pertaining to the size, shape, contour and bony density of the sella turcica and its many components. The advent of tomography and its evolution from linear, to thin-section multidirectional techniques, increased the ability to recognize and to define variations of normal and differentiate them from pathology. However, advances in surgical treatment and the effect this has had on the evaluation of the true significance of radiographic findings, indicated that even these exquisite tomographic techniques were inadequate for the ever-increasing requirement to adequately diagnose pituitary pathology. These requirements have continued to expand as a result of improvement in medical, as well as surgical, treatment.