Skull base CT: normative values for size and symmetry of the facial nerve canal, foramen ovale, pterygoid canal, and foramen rotundum.

PURPOSE: Contrast-enhanced MRI is the mainstay for detecting pathology in the skull base foramina and nerve canals, through demonstration of abnormal enhancement. When MRI is contraindicated, or unable to differentiate tumor from non-neoplastic pathology, high-resolution skull base CT is indicated to assess for nerve canal or foramen widening, which is currently determined subjectively. The purpose of this study is to provide objective CT criteria that may help distinguish between normal asymmetry and pathologic nerve canal or foramen widening. METHODS: Temporal bone CTs of 50 consecutive adults without facial or trigeminal nerve pathology were retrospectively reviewed. Short axis measurements were obtained in the axial plane for three segments of the facial nerve canal (labyrinthine, tympanic, and mastoid), foramen ovale, pterygoid canal and foramen rotundum on both sides in each subject. Descriptive statistics were obtained, and left-right asymmetry was calculated. RESULTS: Nerve canal/foramen size was normally distributed across subjects, with a minimal amount of left-right asymmetry. The upper limits of the 95 % confidence interval for absolute left-right asymmetry were: 0.25, 0.21, and 0.15 mm for the labyrinthine, tympanic, and mastoid segments of the facial nerve canal, respectively; 0.62 mm for foramen ovale; 0.36 mm for pterygoid canal; 0.38 mm for foramen rotundum. CONCLUSION: Relative asymmetry is more important than absolute size for determining nerve canal/foramen abnormality. These normative data may be useful adjuncts to subjective assessments of nerve canal/foramen size when using skull base CT to identify tumor.

Comparison between intensity normalization techniques for dynamic susceptibility contrast (DSC)-MRI estimates of cerebral blood volume (CBV) in human gliomas.

PURPOSE: To compare "standardization," "Gaussian normalization," and "Z-score normalization" intensity transformation techniques in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) estimates of cerebral blood volume (CBV) in human gliomas. DSC-MRI is a well-established biomarker for CBV in brain tumors; however, DSC-MRI estimates of CBV are semiquantitative. The use of image intensity transformation algorithms provides a mechanism for obtaining quantitatively similar CBV maps with the same intensity scaling. MATERIALS AND METHODS: The coefficient of variance (CV) in normal-appearing white matter and relative contrast between tumor regions and normal tissue was compared between the three CBV transformations across five different MR scanners in 96 patients with gliomas. RESULTS: The results suggest all normalization techniques improved variability and relative tumor contrast of CBV measurements compared with nonnormalized CBV maps. The results suggest Gaussian normalization of CBV maps provided slightly lower CV in normal white matter and provided slightly higher tumor contrast for glioblastomas (WHO grade IV) compared with other techniques. CONCLUSION: The results suggest Gaussian normalization of leakage-corrected CBV maps may be the best choice for image intensity correction for use in large-scale, multicenter clinical trials where MR scanners and protocols vary widely due to ease of implementation, lowest variability, and highest tumor to normal tissue contrast.

Klebsiella pneumoniae cervical necrotizing fasciitis originating as an abscess.

Cervical necrotizing fasciitis is a rapidly progressive and devastating infection that is usually caused by a polymicrobial infection including group A Streptococcus and anaerobes. We present a case of a newly diagnosed diabetic man who underwent transoral drainage of a Klebsiella pneumoniae paraglottic abscess, which, despite culture-directed antibiotics, progressed to cervical necrotizing fasciitis with descending mediastinitis. The patient required 12 surgical debridements and sternotomy, but survived and was discharged on hospital day 40. To our knowledge, this is the first case of cervical necrotizing fasciitis caused by a K pneumoniae infection in the United States. The significance of this unusual presentation is discussed.

Cardiac risk after craniopharyngioma therapy.

Although long-term survival after craniopharyngioma treatment is excellent in childhood and early adulthood, sudden deaths in two craniopharyngioma survivors with cardiac findings suggest a need to determine whether treated patients exhibit potential substrates for sudden cardiac death. We present a retrospective review of two index patients with cardiac mortality. This motivated a prospective cardiac screening of 12 survivors that identified nearly a third with significant QTc prolongation. QTc-prolonging medication and stimulants should be used with caution in this population, and routine electrocardiogram screening may identify those at highest risk.

Sinonasal abnormalities in patients with Graves' orbitopathy.

OBJECTIVES: To compare radiographic sinus mucosal thickening in patients with Graves' orbitopathy versus controls and determine whether target autoantigens thought to underlie systemic manifestations of Graves' disease are present within paranasal sinus mucosa. STUDY DESIGN: Case-control study. METHODS: Sinus computed tomography (CT) scans from patients with Graves' orbitopathy scheduled for orbital decompression surgery (n = 50) were compared with maxillofacial CT scans from control patients (n = 50). Scans were rated for sinus mucosal disease by two independent reviewers using the Lund-MacKay and Harvard staging systems. Gene expression for thyrotropin receptor and type 1 insulin-like growth factor receptor (IGF-1R) was assessed in ethmoid mucosal samples using real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). RESULTS: Increased sinus mucosal thickening was found in patients with Graves' orbitopathy compared with controls for both the Lund-MacKay (6.2 vs. 2.7; P < .01) and Harvard (2.1 vs. 1.3; P < .01) systems. Compared with control scans, the Graves' orbitopathy group exhibited greater mucosal thickening in the ethmoid, frontal, and sphenoid sinuses (P < .05 for all). RT-qPCR and IHC demonstrated gene expression for both the thyrotropin receptor and the IGF-1R in ethmoid mucosa. CONCLUSIONS: Patients with Graves' orbitopathy who present for orbital decompression exhibit a higher prevalence of sinus mucosal thickening on CT scan. These findings may be explained by circulating autoantibodies to target antigens, thyrotropin receptor and IGF-1R, associated with Graves' disease and found to be expressed in sinus mucosa.

Fallopian canal meningocele: report of two cases.

OBJECTIVE: The purpose of this study is to report 2 rare cases of congenital fallopian canal meningoceles. INTERVENTIONS: Magnetic resonance imaging, computed tomography (CT) of the temporal bone, CT-cisternogram, and combined transmastoid approach with middle fossa craniotomy in 2 patients. MAIN OUTCOME MEASURES: Radiologic and operative diagnosis of congenital fallopian canal meningoceles. RESULTS: Presentations included spontaneous cerebrospinal fluid (CSF) otorrhea and recurrent meningitis with intracranial hypertension. Postoperative complications included facial nerve palsy and persistent CSF leaks that necessitated ventriculoperitoneal shunt and lumbar drain placement. CONCLUSION: Use of CT of the temporal bone in combination with CT-cisternogram may define sites of active CSF leak. Intraoperative use of fluorescein may assist identification of cranial base defects to lower rates of recurrence, and intraoperative use of cranial nerve monitoring can minimize the risk of nerve injury during repair.