Imaging as an early biomarker to predict sensitivity to everolimus for progressive NF2-related vestibular schwannoma.

PURPOSE: NF2-related schwannomatosis (NF2) is characterized by bilateral vestibular schwannomas (VS) often causing hearing and neurologic deficits, with currently no FDA-approved drug treatment. Pre-clinical studies highlighted the potential of mTORC1 inhibition in delaying schwannoma progression. We conducted a prospective open-label, phase II study of everolimus for progressive VS in NF2 patients and investigated imaging as a potential biomarker predicting effects on growth trajectory. METHODS: The trial enrolled 12 NF2 patients with progressive VS. Participants received oral everolimus daily for 52 weeks. Brain imaging was obtained quarterly. As primary endpoint, radiographic response (RR) was defined as ≥ 20% decrease in target VS volume. Secondary endpoints included other tumors RR, hearing outcomes, drug safety and quality of life (QOL). RESULTS: Eight participants completed the trial and four discontinued the drug early due to significant volumetric VS progression. After 52 weeks of treatment, the median annual VS growth rate decreased from 77.2% at baseline to 29.4%. There was no VS RR and 3 of 8 (37.5%) participants had stable disease. Decreased or unchanged VS volume after 3 months of treatment was predictive of stabilization at 12 months. Seven of eight participants had stable hearing during treatment except one with a decline in word recognition score. Ten of twelve participants reported only minimal changes to their QOL scores. CONCLUSIONS: Volumetric imaging at 3 months can serve as an early biomarker to predict long-term sensitivity to everolimus treatment. Everolimus may represent a safe treatment option to decrease the growth of NF2-related VS in patients who have stable hearing and neurological condition. TRN: NCT01345136 (April 29, 2011).

Bilateral Endolymphatic Hydrops in a Patient With Migraine Variant Without Vertigo: A Case Report.

OBJECTIVE: To use modern high-resolution inner ear imaging modalities to evaluate for endolymphatic hydrops (EH) in a patient with migraine-associated fluctuating hearing loss without vertigo spells or dizziness. BACKGROUND: EH has been well described in patients with Meniere's disease on both human temporal bone studies and modern high-resolution imaging; however, there is no study to date, to our knowledge, that examines the presence of EH in a patient with migraine and bilateral hearing loss. We present the MRI findings using a sequence for detecting EH in a unique case of a patient experiencing migraine headaches accompanied by fluctuating hearing loss without vertigo. METHODS: Magnetic resonance imaging sequences included "cisternographic" three-dimensional T2, and delayed intravenous-enhanced three-dimensional fluid-attenuation inversion recovery (DIVE-3D-FLAIR) sequences, performed with 2350 ms (bright perilymph) and 2050 ms (bright endolymph) inversion times. The bright endolymph images were subtracted from bright perilymph images to create a composite image with bright perilymph, dark endolymph, and intermediate bone signals. RESULTS: A 40-year-old female presented with a left-sided sensorineural hearing loss and severe migraine headaches that began at age 12. For the past year, she experienced severe migraines with right-sided fluctuating sensorineural hearing loss, tinnitus, and aural fullness. Audiometry confirmed a drop of right-sided hearing at times of migraines and increased symptom severity. Vestibular testing was within normal limits. MRI demonstrated the presence of severe bilateral vestibular and cochlear EH. CONCLUSIONS: EH of both the cochlea and vestibule can be present in patients without Meniere's disease or vertigo. The relationship between migraine and Meniere's disease may be complex, as demonstrated in this patient with migraine-associated bilateral hearing loss with MRI documentation of severe bilateral EH. The fact that migraine can be associated with EH is important and demonstrates a potential relationship between the pathophysiology of migraine and that of EH. Given this patient's previous association of migraine and hearing loss at age 12, it appears that migrainous attacks occur simultaneously with the hearing loss, and may be potentially causative of the fluctuating hearing loss, mediated possibly through the development of EH. New imaging modalities allow for studies into the field of inner ear pathology, with significant implications for future research.

Hypopharyngeal venous malformation presenting with foreign body sensation and dysphagia.

OBJECTIVE: Review the importance of imaging selection and clinicoanatomic correlation for a vascular malformations presenting with unique symptomatology. METHODS: Case study and literature review. RESULTS: A 64-year-old female presented with globus and dysphagia ongoing for 40 years. Esophagogastroduodenoscopy discovered a hypopharyngeal mass. A CT scan showed a soft tissue mass with shotty calcifications. Flexible laryngoscopy revealed a bluish compressible mass. MRI showed T2 hyperintensity with heterogeneous enhancement resulting in the diagnosis of a low-flow vascular malformation. CONCLUSIONS: All globus is not equal. Attention to symptoms, anatomy, and imaging selection is crucial for the diagnosis and treatment of vascular malformations uniquely presenting with dysphagia.

Parathyroid Adenomas and Hyperplasia on Four-dimensional CT Scans: Three Patterns of Enhancement Relative to the Thyroid Gland Justify a Three-Phase Protocol.

PURPOSE: To describe the prevalence of three relative enhancement patterns of parathyroid lesions on four-dimensional (4D) computed tomographic (CT) scans. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study and waived the need for informed consent. The authors retrospectively reviewed preoperative 4D CT scans obtained from November 2012 to June 2014 in 94 patients with pathologically proven parathyroid adenomas or hyperplasia. Lesions were classified into one of three relative enhancement patterns. All patterns required lesions to be lower in attenuation than the thyroid on non-contrast material-enhanced images, but patterns differed in the two contrast-enhanced phases. Type A lesions were higher in attenuation than the thyroid in the arterial phase, type B lesions were not higher in attenuation than the thyroid in the arterial phase but were lower in attenuation than the thyroid in the delayed phase, and type C lesions were neither higher in attenuation than the thyroid in the arterial phase nor lower in attenuation than the thyroid in the delayed phase. The prevalence of the relative enhancement patterns was compared. The t test was used to compare mean attenuation differences in Hounsfield units between the relative enhancement patterns. RESULTS: Ninety-four patients had 110 parathyroid lesions, including 11 patients with multigland disease. The sensitivity for single-gland disease was 94% (78 of 83) and that for multigland disease was 59% (16 of 27). Type B enhancement was most common, with a prevalence of 57% (54 of 94), followed by type C (22% [21 of 94]) and type A (20% [19 of 94]). Five lesions were interpreted incorrectly as parathyroid adenoma (false-positive), and all lesions had the type C pattern. Relative to the thyroid, lesions categorized as type A by readers had mean attenuation difference (± standard deviation) of 39 HU ± 13 in the arterial phase, and type B lesions had a difference of -58 HU ± 26 in the delayed phase. These values differed from the mean attenuation difference of lesions not in these categories (P < .001). CONCLUSION: Parathyroid adenomas and hyperplasia can be grouped into three relative enhancement patterns based on a protocol with a non-contrast-enhanced and two contrast-enhanced phases. The type B pattern is most common and could be diagnosed with two contrast-enhanced phases. However, almost one quarter of lesions have the type C pattern and thus could be missed without the non-contrast-enhanced phase.

Dynamic Parathyroid Computed Tomography (4DCT) Facilitates Reoperative Parathyroidectomy and Enables Cure of Missed Hyperplasia.

BACKGROUND: Four-dimensional computed tomography (4DCT) is an emerging imaging modality in the evaluation of primary hyperparathyroidism (PHPT). We assessed the role of 4DCT in patients presenting for reoperative parathyroidectomy. METHODS: A prospective database of patients with persistent or recurrent PHPT undergoing reoperative parathyroidectomy during the years 2006-2014 was analyzed. Patients treated before versus after the advent of 4DCT were compared for operative eligibility, operative success, operative time, and concordance of imaging results with surgical findings. RESULTS: Ninety patients were included in the study (61 before 4DCT, 29 after 4DCT). The post-4DCT group had a higher rate of surgical concordance with imaging results (63 vs. 90 %, p < 0.01) and shorter operative time (114 vs. 76 min, p < 0.05). The operative success rate was not different (87 vs. 86 %). A similar pattern was observed in the subset of sestamibi-negative patients, with post-4DCT patients having a higher rate of surgical concordance (12 vs. 83 %, p < 0.0001) and shorter operative time (181 vs. 89 min, p < 0.05). Among patients ultimately found to have parathyroid hyperplasia, 4DCT correctly identified multiple enlarged glands in 80 % (4 of 5) and correctly lateralized one or more glands in 100 % (5 of 5) of cases, facilitating successful subtotal parathyroidectomy in the reoperative setting. CONCLUSIONS: 4DCT enables successful and efficient reoperative parathyroidectomy. These benefits extend to difficult cases, including sestamibi-negative patients and those with missed hyperplasia.

Quantitative multiparametric MRI in uveal melanoma: increased tumor permeability may predict monosomy 3.

INTRODUCTION: Uveal melanoma is a rare intraocular tumor with heterogeneous biological behavior, and additional noninvasive markers that may predict outcome are needed. Diffusion- and perfusion-weighted imaging may prove useful but have previously been limited in their ability to evaluate ocular tumors. Our purpose was to show the feasibility and potential value of a multiparametric (mp-) MRI protocol employing state of the art diffusion- and perfusion-weighted imaging techniques. METHODS: Sixteen patients with uveal melanoma were imaged with mp-MRI. Multishot readout-segmented echoplanar diffusion-weighted imaging, quantitative dynamic contrast-enhanced (DCE) MR perfusion imaging, and anatomic sequences were obtained. Regions of interest (ROIs) were drawn around tumors for calculation of apparent diffusion coefficient (ADC) and perfusion metrics (K (trans) , v e , k ep , and v p ). A generalized linear fit model was used to compare various MRI values with the American Joint Commission on Cancer (AJCC) tumor group and monosomy 3 status with significance set at P < 0.05. RESULTS: mp-MRI was performed successfully in all cases. MRI tumor height (mean [standard deviation]) was 6.5 mm (3.0). ROI volume was 278 mm(3) (222). ADC was 1.07 (0.27) × 10-3 mm(2)/s. DCE metrics were K (trans) 0.085/min (0.063), v e 0.060 (0.052), k ep 1.20/min (0.32), and v p 1.48 % (0.82). Patients with >33 % monosomy 3 had higher K (trans) and higher v e values than those with disomy 3 or ≤33 % monosomy (P < 0.01). There were no significant differences between ADC (P = 0.07), k ep (P = 0.37), and v p with respect to monosomy 3. CONCLUSION: mp-MRI for ocular tumor imaging using multishot EPI DWI and quantitative DCE perfusion is technically feasible. mp-MRI may help predict monosomy 3 in uveal melanoma.

Biomimetic scaffolds facilitate healing of critical-sized segmental mandibular defects.

OBJECTIVE: To investigate the efficacy of biomimetic PLGA scaffolds, alone and in combination with bone morphogenic protein (BMP-2) and adipose-derived stem cells (ASCs), to heal a critical-sized segmental mandibular defect in a rat model. STUDY DESIGN: Prospective animal study. METHODS: ASCs were isolated and cultured from the inguinal fat of Lewis rat pups. Using three-dimensional printing, PLGA scaffolds were fabricated and impregnated with BMP-2 and/or ASCs. Critical-sized 5-mm segmental mandibular defects were created in adult Lewis rats and implanted with (1) blank PLGA scaffolds, (2) PLGA scaffolds with ASCs, (3) PLGA scaffolds with BMP, or (4) PLGA scaffolds with BMP and ASCs. Animals were sacrificed at 12weeks. Bone regeneration was assessed using microCT, and graded on a semi-quantitative bone formation and bone union scale. RESULTS: Twenty-eight rats underwent creation of segmental mandibular defects with implantation of scaffolds. Nine rats suffered complications and were excluded from analysis, leaving 19 animals for inclusion in the study. MicroCT analysis demonstrated no bridging of the segmental bony defect in rats implanted with blank scaffolds (median bone union score=0). Rats implanted with scaffolds containing BMP-2 (median bone union=2.0), ASCs (median bone union=1.5), and combination of BMP and ASCs (median bone union=1.0) demonstrated healing of critical-sized segmental mandibular defects. Bone regeneration was most robust in the BMP-2 treated scaffolds. CONCLUSIONS: The current study utilizes a novel animal model to study the efficacy of biomimetic scaffolds carrying osteogenic factors to induce healing of a critical-sized segmental mandibular defect. LEVEL OF EVIDENCE: N/A, Basic Science Animal Research.

MRI criteria for the diagnosis of pleomorphic adenoma: a validation study.

OBJECTIVES: To validate an MRI algorithm characteristic of pleomorphic adenoma (PA). STUDY DESIGN: Cross-sectional analysis. SETTING: Academic tertiary-care medical center. METHODS: A radiologic algorithm for the MRI diagnosis of PA was developed on the basis of five "high probability" criteria that all must be fulfilled for the MRI to qualify as a positive test result: bright T2-signal, sharp margins, heterogeneous nodular enhancement, lobulated contours, T2-dark rim. We then identified MRI images from our institutional database to test the diagnostic accuracy of the proposed algorithm. RESULTS: A total of 103 parotidectomy cases with adequate MRI studies were identified (pleomorphic adenoma n=41, mucoepidermoid carcinoma n=11, Warthin's tumor n=8, adenoid cystic carcinoma n=6, oncocytoma n=6, acinic cell carcinoma n=5, salivary duct carcinoma n=5, and other n=21). Eighteen of 21 cases that met all five "high probability" MRI criteria were consistent with PA on final histopathology; 3 were consistent with carcinoma. MRI had a specificity of 95.1% [95% confidence interval: 85.6-98.7%] and sensitivity of 43.9% [95% C.I.: 28.8-60.1%] for PA. The positive predictive value was 85.7% [95% C.I.: 70.4-100%] and the negative predictive value was 71.9% [95% C. I.: 62.0-81.9%]. The overall diagnostic accuracy was 74.8% [95% C.I.: 66.2-83.3%]. CONCLUSION: A "high probability" MRI is about 95% specific for pleomorphic adenoma. A subset of patients with MRI imaging that is highly suggestive of PA may reliably avoid further workup. The value of MRI in this setting is especially useful if preoperative fine needle aspiration is not readily available. A significant proportion of PAs, however, have indeterminate imaging features that overlap considerably with other benign and malignant lesions.

Early Experience with a Novel Treatment for Menière's Disease: A Long Acting Dexamethasone Formulation for Precise Delivery to the Round Window Membrane.

OBJECTIVE: To investigate the safety and feasibility of precise delivery of a long-acting gel formulation containing 6% dexamethasone (SPT-2101) to the round window membrane for the treatment of Menière's disease. STUDY DESIGN: Prospective, unblinded, cohort study. SETTING: Tertiary care neurotology clinic. PATIENTS: Adults 18 to 85 years with a diagnosis of unilateral definite Menière's disease per Barany society criteria. INTERVENTIONS: A single injection of a long-acting gel formulation under direct visualization into the round window niche. MAIN OUTCOME MEASURES: Procedure success rate, adverse events, and vertigo control. Vertigo control was measured with definitive vertigo days (DVDs), defined as any day with a vertigo attack lasting 20 minutes or longer. RESULTS: Ten subjects with unilateral Menière's disease were enrolled. Precise placement of SPT-2101 at the round window was achieved in all subjects with in-office microendoscopy. Adverse events included one tympanic membrane perforation, which healed spontaneously after the study, and two instances of otitis media, which resolved with antibiotics. The average number of DVDs was 7.6 during the baseline month, decreasing to 3.3 by month 1, 3.7 by month 2, and 1.9 by month 3. Seventy percent of subjects had zero DVDs during the third month after treatment. CONCLUSIONS: SPT-2101 delivery to the round window is safe and feasible, and controlled trials are warranted to formally assess efficacy.

Three-phase parathyroid 4-dimensional computed tomography initial experience: inexperienced readers have high accuracy and high interobserver agreement.

OBJECTIVE: Multiphase multidetector contrast-enhanced parathyroid CT (4-dimensional computed tomography [4D-CT]) is an emerging tool for evaluating patients with primary hyperparathyroidism. Our goal was to describe the initial performance of 2 inexperienced readers in interpretation of 4D-CT. METHODS: Twenty-three subjects who received 4D-CT and successful surgical exploration were studied (14 initial and 9 repeat explorations; 15 single-gland disease and 8 multigland disease) A staff neuroradiologist prospectively interpreted all studies, and a neuroradiology fellow retrospectively interpreted all studies; their results were compared with the surgical findings for each side of the neck separately. RESULTS: The prospective readings were 78% accurate overall, 97% accurate in the subset of single-gland disease cases, and 89% accurate in re-exploration cases. There was 91% concordance in interpretation between observers, with κ of 0.83. CONCLUSIONS: Initial results after implementation of 4D-CT show high accuracy of interpretation for inexperienced observers, comparable to published data, and high interobserver agreement.

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.

Olfactory Neuroblastoma: Re-Evaluating the Paradigm of Intracranial Extension and Cyst Formation.

The purpose of the current study was to assess the prevalence of cyst formation at the brain-tumor interface in olfactory neuroblastoma. We used the UCLA patient-based Pathology and Radiology Head and Neck Database (UPP&R HAND) to identify the largest patient cohort reported to date with imaging and pathology data. Eighteen of thirty-one patients (58.1%) had evidence of intracranial extension on MRI, while four (22.0%) demonstrated cyst formation at the brain-tumor interface. The extent of intracranial extension was by far the strongest predictor for intracranial cyst formation, regardless of Hyams tumor grade, using a binary logistics regression model (p = 0.002) and ROC curve analysis (AUC 94.6%). Cyst formation at the brain-tumor interface was an uncommon imaging finding, and tends to occur with a larger component of intracranial tumor extension.

Neurotropic Cutaneous Malignancies: Case Report on Keratinocyte Derived Malignancies of the Head and Neck With Perineural Invasion.

Background: The recent addition of immunotherapy as a treatment modality to surgery and radiation has vastly improved disease control for patients with keratinocyte-derived carcinomas (KCs) that are incurable with local therapies alone. With the advent of immune checkpoint inhibitors (ICPis) in non-melanoma skin cancers comes diagnostic and therapeutic challenges when considering treatment strategies for patients presenting with clinical perineural invasion (cPNI) of locally advanced KC of the head and neck. Objectives: We report four cases that convey the diagnostic and therapeutic complexity of managing patients with neuropathic symptoms from cutaneous neurotropic carcinomas of the head and neck. We also discuss an updated review regarding immunotherapies and perineural invasion within KC management. Conclusion: Patients presenting with symptoms suspicious for cPNI warrant an expanded diagnostic evaluation to correlate neurological findings with neurotropic spread of disease. While nerve biopsies can be precarious in sensitive areas, a history of skin cancer and clinical presentation suggestive of neurotropism may be enough to pursue timely management in the form of surgery, radiation, and/or systemic therapy given each patient's individual priorities, comorbidities, and prognosis. When adding ICPi as a treatment modality for patients with disease not amenable to local therapies, the potential for immune-related adverse events must be considered. A multi-disciplinary review and approach to the management of patients with KC and cPNI is essential for obtaining optimal patient outcomes.

Indeterminate orbital masses: restricted diffusion at MR imaging with echo-planar diffusion-weighted imaging predicts malignancy.

PURPOSE: To determine whether magnetic resonance (MR) imaging with diffusion-weighted (DW) imaging can help discriminate between radiologically indeterminate benign and malignant orbital masses and to identify optimal apparent diffusion coefficient (ADC) thresholds for such discrimination. MATERIALS AND METHODS: Informed consent was waived for this HIPAA-compliant institutional review board-approved retrospective study. Forty-seven orbital masses imaged with echo-planar DW imaging were identified in 47 patients (25 female patients, 22 male patients; average age, 35 years). A fellowship-trained orbital surgeon determined reference-standard diagnoses on the basis of chart review, and a neuroradiology fellow and senior neuroradiologist who were blinded to the diagnoses selected a region of interest for each lesion by consensus. ADC was calculated from signal intensity on DW images obtained with b = 1000 and b = 0 sec/mm(2). Lesion ADC was also compared with that of normal-appearing white matter (ADC ratio). The Student t test was used to compare groups. Receiver operating characteristic analysis was performed. Intraobserver agreement was assessed with a repeat data collection. RESULTS: Malignant lesions had lower ADCs than benign lesions, irrespective of patient age (P < .02) and in adults specifically (P < .05). Lymphomas had lower ADCs than pseudotumors (P < .001). An ADC of less than 1.0 x 10(-3) mm(2)/sec and an ADC ratio of less than 1.2 were optimal for predicting malignancy (sensitivity, 63% for both; specificity, 84% and 90%, respectively; and accuracy, 77% and 81%, respectively). Lymphoma was differentiated from pseudotumor with 100% accuracy (in 16 of 16 cases) by using these values. Infiltrative lesions that were hypointense on T2-weighted images were better characterized with DW imaging than lesions that were hyperintense or well defined. CONCLUSION: Echo-planar DW MR imaging can help characterize indeterminate orbital masses.

MRI of orbital cellulitis and orbital abscess: the role of diffusion-weighted imaging.

OBJECTIVE: Our aims were to describe the role of diffusion-weighted imaging (DWI) in detecting abscess as a complication of orbital cellulitis and to assess whether abscess can be diagnosed with a combination of conventional unenhanced sequences and whole-brain DWI with parallel acquisition. Nine cases of orbital cellulitis imaged with MRI were retrospectively reviewed, including six cases with pyogenic abscess. CONCLUSION: In this preliminary study, DWI improved diagnostic confidence in nearly all cases of orbital abscess when used in conjunction with contrast-enhanced imaging. DWI also confirmed abscess in a majority of cases without contrast-enhanced imaging, which may be of particular use when contrast material is contraindicated.

High Resolution Three-Dimensional Delayed Contrast MRI Detects Endolymphatic Hydrops in Patients With Vertigo and Vestibular Schwannoma.

OBJECTIVE: Advances in high resolution magnetic resonance imaging (MRI) have enabled the detection of endolymphatic hydrops (EH), a pathological ballooning of the endolymphatic fluid system, known to be associated with Menière's disease. When a patient has a known diagnosis of vestibular schwannoma and develops recurrent episodic vertigo spells, many surgeons recommend surgical intervention, attributing the vestibular symptoms to the vestibular schwannoma. The aim of this study is to evaluate the clinical outcome in patients with vestibular schwannoma and EH, treated medically, for recurrent spells of vertigo. PATIENTS: Two patients with EH and vestibular schwannoma who presented with recurrent spells of vertigo are included. Both had characteristic low frequency hearing loss ipsilateral to the schwannoma. INTERVENTION: MRI sequences with 3T scanner (Skyra, Siemens Healthcare, Erlangen, Germany) using high resolution three-dimensional delayed postcontrast protocol included "cisternographic" T2 and delayed intravenous-enhanced three-dimensional fluid-attenuation inversion recovery (DIVE-3D-FLAIR) sequences, performed with 2350 ms (bright perilymph) and 2050 ms (bright endolymph) inversion times and with subtracted images. MAIN OUTCOME MEASURE: MRI FLAIR evaluation of EH and presence or absence of vestibular symptoms. RESULTS: Both patients had resolution of the disabling vertigo spells with a diuretic, and Patient 1 had unchanged EH, while Patient 2 had partial resolution of the EH and the FLAIR hyperintensity. CONCLUSION: When EH coexists with vestibular schwannoma in a patient presenting with recurrent vertigo spells, medical treatments for EH may alleviate the vestibular symptoms. We recommend that patients with small vestibular schwannomas who present with vertigo spells undergo high resolution MRI to evaluate for EH and undergo a trial of medical treatment with diuretics.

A Story in Black and White: Radiologic Evaluation in the Multidisciplinary Setting.

Strong engagement from expert radiologists is essential in ensuring the optimal function of a multidisciplinary group focused on the treatment of head and neck cancer. Active participation in multidisciplinary conference can be among the most rewarding roles for radiologists. Despite many benefits to radiologist involvement in multidisciplinary teams, there are obstacles and challenges that can prevent full participation. This article highlights the key issues that should be considered by radiologists and multidisciplinary team leaders when planning participation in a new or existing multidisciplinary group that focuses on the care of patients with head and neck cancer.

Factors Associated With Discordance Between Preoperative Parathyroid 4-Dimensional Computed Tomographic Scans and Intraoperative Findings During Parathyroidectomy.

IMPORTANCE: Parathyroid 4-dimensional computed tomographic scans (4D-CTs) have emerged as an accurate and cost-effective initial localization study for patients with primary hyperparathyroidism. However, potential limitations and factors affecting the accuracy of preoperative 4D-CTs remain poorly defined. OBJECTIVES: To characterize factors associated with missed parathyroid lesions on preoperative 4D-CTs and to investigate patterns of commonly observed errors. DESIGN, SETTING, AND PARTICIPANTS: A prospectively accrued patient database was analyzed from September 1, 2011, through October 31, 2016. The study was performed in a tertiary referral center. Consecutive patients with primary hyperparathyroidism undergoing preoperative 4D-CTs and subsequent parathyroidectomy were included in the study. MAIN OUTCOMES AND MEASURES: Discordance between preoperative 4D-CTs and intraoperative findings in the number and location of abnormal parathyroid lesions. RESULTS: Of 411 patients studied (mean [SD] age, 59 [14] years; 325 [79.1%] female), 123 (29.9%) had discordance between preoperative 4D-CTs and intraoperative findings. Among the 411 patients, 75 (18.2%) had major discordance, including incorrectly localized adenoma on the contralateral side of the neck, missed double adenoma, and absence of any abnormal lesion detected on 4D-CTs. Compared with concordant cases, discordant cases had higher frequencies of multigland disease (66.7% [82 of 123] vs 24.3% [70 of 288], P < .001) and multinodular goiter or thyroid nodule (40.7% [50 of 123] vs 29.2% [84 of 288], P = .02). Missed parathyroid lesions were smaller (mean [SD], 0.86 [0.29] vs 1.24 [0.50] cm; P < .001) and were more likely to be in the inferior position (65.4% [87 of 133] vs 38.1% [177 of 465], P < .001). Parathyroid lesion size of 10 mm or less (odds ratio [OR], 4.37; 95% CI, 2.24-8.54), multigland disease (OR, 7.63; 95% CI, 3.49-16.69), multinodular goiter or thyroid nodule (OR, 1.82; 95% CI, 1.01-3.28), and parathyroid lesion in the inferior position (OR, 6.82; 95% CI, 3.10-14.99) were independently associated with discordant 4D-CT results. CONCLUSIONS AND RELEVANCE: Multigland disease was most strongly associated with discordance between preoperative 4D-CTs and intraoperative findings, followed by parathyroid lesion in the inferior position and parathyroid lesion size of 10 mm or less. Awareness of these potential pitfalls may allow surgeons to better leverage this new localization technique in preoperative planning and intraoperative troubleshooting.

Anatomic Variations in Pituitary Endocrinopathies: Implications for the Surgical Corridor.

Objectives/Hypotheses Functioning pituitary adenomas may produce endocrinopathies such as acromegaly and Cushing syndrome. Both conditions lead to characteristic anatomic variations as a result of hormonally induced abnormal soft tissue deposition. We evaluate the anatomic differences between acromegalics and Cushing disease patients and compare these dimensions to controls. Design Radiographic review of preoperative magnetic resonance images (MRI) of the pituitary gland. Setting Tertiary academic medical center. Participants Patients who underwent transnasal, transsphenoidal surgery for pituitary adenomas found to have acromegaly or pituitary Cushing between January 1, 2007 and September 1, 2015. A total of 15 patients with similar MRIs and no history of pituitary or sinonasal disease were selected as controls. Main Outcome Measures Dimensions assessed were intercarotid distance; carotid canal width; piriform aperture width; distance from the piriform aperture to the anterior face of the sphenoid; sphenoid sinus height, width, and length; angle from anterior nasal spine to anteroinferior face of sphenoid sinus; choanal height; and nasal cavity height at the level of the vertical segment of the middle turbinate. Sphenoid sinus pneumatization patterns were recorded. Results There were 30 acromegalics and 31 Cushing disease patients. When compared with controls, both acromegalics and Cushing disease patients had significantly wider piriform apertures and a longer distance from the piriform aperture to the anterior face of the sphenoid sinus (p < 0.05). Acromegalics had a significantly less acute angle (19 ± 3 degrees) from the anterior nasal spine to the sphenoid (p < 0.05). Cushing disease patients had significantly lower sphenoid sinus length and shorter nasal cavity height (p < 0.05). There were no differences in intercarotid distance or carotid canal width. Conclusions As acromegalics and Cushing disease patients have known anatomic variations, the skull base surgeon should be aware of these differences and adapt their techniques and approaches as needed.

High Resolution MRI Shows Presence of Endolymphatic Hydrops in Patients Still Symptomatic After Endolymphatic Shunt Surgery.

OBJECTIVE: Endolymphatic hydrops has been well described in patients with Ménière's syndrome; however, causation has not been established. Decompression of the endolymphatic sac has been proposed as a means to relieve hydrops and improve vertigo symptoms, but the efficacy of the surgery is debated. Until recently, there have been few objective measures of efficacy other than patients' subjective symptoms. Recent archival human temporal bone studies have shown that patients continue to have hydrops after shunt surgery. We propose using high-resolution magnetic resonance imaging (MRI) to determine the efficacy of endolymphatic shunt surgery (ELS) in patients who continue to experience vertigo. PATIENTS: Four patients presented with continued vertigo after ELS. INTERVENTIONS: Magnetic resonance imaging sequences included "cisternographic" three-dimensional T2, and delayed intravenous-enhanced three-dimensional fluid-attenuation inversion recovery (DIVE-3D-FLAIR) sequences, performed with 2350 ms (bright perilymph) and 2050 ms (bright endolymph) inversion times. The bright endolymph images were subtracted from bright perilymph images to create a composite image with bright perilymph, dark endolymph, and intermediate bone signals. MAIN OUTCOME MEASURES: MRI finding of endolymphatic hydrops. RESULTS: In all five affected ears in four patients who continued to experience severe vertigo, hydrops was found on high resolution MRI on the operated ear. The appearance on MRI was no different than in patients with endolymphatic hydrops (EH) who have not had surgery. CONCLUSIONS: The present study demonstrates the persistence of endolymphatic hydrops in patients who have failed ELS. Future studies evaluating for the presence or absence of endolymphatic hydrops in patients who claim to obtain relief from ELS.