CT-based diagnosis in patients presenting with throat pain: A single institutional review

RATIONALE AND OBJECTIVE

To determine if patient demographic data, medical history, physical examination, and laboratory tests will help predict likelihood of imaging-based diagnosis using CT of the neck performed in the ED for a chief complaint of throat pain.

MATERIAL AND METHODS

Single institutional, retrospective review of 367 CT scans of the neck performed for the evaluation of throat pain in the ED from August 2013 to September 2019. Patients' clinical history, physical exams, lab findings, and imaging results were recorded.

RESULTS

A total of 367 CT scans of the neck performed for the evaluation of throat pain included a recorded exam and clinical history. Of these cases, we noted that the presence of cervical lymphadenopathy (OR = 2.69; 95% CI, 1.37-5.49), tonsillar findings (OR = 2.94; 95% CI, 1.4-6.57), increased white blood cell count (OR = 1.08; 95% CI, 1.02-1.15), and temperature (OR = 1.94; 95% CI, 1.1-3.6) were associated with increased likelihood of obtaining a diagnostic CT scan.

CONCLUSION

Consideration of tonsillar abnormalities, lymphadenopathy, body temperature, and measured leukocyte count prior to ordering CT scans of the neck for throat pain may increase the diagnostic yield of such exams and decrease CT utilization in the ED.

Posterior hypothalamic involvement on pre-operative MRI predicts hypothalamic obesity in craniopharyngiomas

PURPOSE

Hypothalamic obesity (HO) is a complication associated with craniopharyngioma (CP). Attempts have been made to perioperatively predict the development of this complication, which can be severe and difficult to treat.

METHODS

Patients who underwent first transsphenoidal surgical resection in a single center between February 2005 and March 2019 were screened; those who have had prior surgery or radiation, were aged below 18 years, or did not have follow up body mass index (BMI) after surgery were excluded. Primary end point was BMI within 2 years post-surgery. Hypothalamic involvement (HI) was graded based on preoperative and postoperative imaging with regards to anterior, posterior, left and right involvement. Data on baseline demographics, pre-operative and post-operative MRI, and endocrine function were collected.

RESULTS

45 patients met the inclusion and exclusion criteria. Most patients in our cohort underwent gross total resection (n = 35 patients). 13 patients were from no HI or anterior HI only group and 22 patients were classified as both anterior (ant) and posterior (post) HI group. There was no significant difference between the two groups in the gross total, subtotal or near total resection. Pre-operative BMI and post-operative BMI were significantly higher in patients who had ant and post HI on pre-operative MRI (p < 0.05 and p < 0.01, respectively). Similarly, post-operative BMI at 13-24 months was also significantly higher in the ant and post HI group on post-op MRI (p < 0.01). There was no significant difference between the two groups in terms of baseline adrenal insufficiency, thyroid insufficiency, gonadal insufficiency, IGF-1 levels, hyperprolactinemia, and diabetes insipidus. Diabetes insipidus was more common following surgery among those who had anterior and posterior involvement on pre-operative MRI (p < 0.05).

CONCLUSIONS

HO appears to be predetermined by tumor involvement in the posterior hypothalamus observed on pre-operative MRI. Posterior HI on pre-operative MRI was also associated with the development of diabetes insipidus after surgery.

A Gamified Social Media-Based Head and Neck Radiology Education Initiative of the American Society of Head and Neck Radiology: Viewership and Engagement Trends at 3 Years

BACKGROUND AND PURPOSE

Social media has made inroads in medical education. We report the creation and 3-year (2018-2021) longitudinal assessment of the American Society of Head and Neck Radiology Case of the Week (#ASHNRCOTW), assessing viewership, engagement, and impact of the coronavirus disease 2019 (COVID-19) pandemic on this Twitter-based education initiative.

MATERIALS AND METHODS

Unknown cases were tweeted from the American Society of Head and Neck Radiology account weekly. Tweet impressions (number of times seen), engagements (number of interactions), and new followers were tabulated. A social media marketing platform identified worldwide distribution of Twitter followers. Summary and t test statistics were performed.

RESULTS

#ASHNRCOTW was highly visible with 2,082,280 impressions and 203,137 engagements. There were significantly greater mean case impressions (9917 versus 6346), mean case engagements (1305 versus 474), case engagement rates (13.06% versus 7.76%), mean answer impressions (8760 versus 5556), mean answer engagements (908 versus 436), answer engagement rates (10.38% versus 7.87%), mean total (case + answer) impressions (18,677 versus 11,912), mean total engagements (2214 versus 910), and total engagement rates (11.79% versus 7.69%) for cases published after the pandemic started (all P values < .001). There was a significant increase in monthly new followers after starting #ASHNRCOTW (mean, 134 versus 6; P < .001) and significantly increased monthly new followers after the pandemic started compared with prepandemic (mean, 178 versus 101; P = .003). The American Society of Head and Neck Radiology has 7564 Twitter followers throughout 130 countries (66% outside the United States).

CONCLUSIONS

Social media affords substantial visibility, engagement, and global outreach for radiology education. #ASHNRCOTW viewership and engagement increased significantly during the COVID-19 pandemic.

Segmentation of Vestibular Schwannomas on Postoperative Gadolinium-Enhanced T1-Weighted and Noncontrast T2-Weighted Magnetic Resonance Imaging Using Deep Learning

OBJECTIVE

Surveillance of postoperative vestibular schwannomas currently relies on manual segmentation and measurement of the tumor by content experts, which is both labor intensive and time consuming. We aimed to develop and validate deep learning models for automatic segmentation of postoperative vestibular schwannomas on gadolinium-enhanced T1-weighted magnetic resonance imaging (GdT1WI) and noncontrast high-resolution T2-weighted magnetic resonance imaging (HRT2WI).

STUDY DESIGN

A supervised machine learning approach using a U-Net model was applied to segment magnetic resonance imaging images into pixels representing vestibular schwannoma and background pixels.

SETTING

Tertiary care hospital.

PATIENTS

Our retrospective data set consisted of 122 GdT1WI and 122 HRT2WI studies in 82 postoperative adult patients with a vestibular schwannoma treated with subtotal surgical resection between September 1, 2007, and April 17, 2018. Forty-nine percent of our cohort was female, the mean age at the time of surgery was 49.8 years, and the median time from surgery to follow-up scan was 2.26 years.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Tumor areas were manually segmented in axial images and used as ground truth for training and evaluation of the model. We measured the Dice score of the predicted segmentation results in comparison to manual segmentations from experts to assess the model's accuracy.

RESULTS

The GdT1WI model achieved a Dice score of 0.89, and the HRT2WI model achieved a Dice score of 0.85.

CONCLUSION

We demonstrated that postoperative vestibular schwannomas can be accurately segmented on GdT1WI and HRT2WI without human intervention using deep learning. This artificial intelligence technology has the potential to improve the postoperative surveillance and management of patients with vestibular schwannomas.

High-Resolution T2-Weighted Imaging for Surveillance in Postoperative Vestibular Schwannoma: Equivalence with Contrast-Enhanced T1WI for Measurement and Surveillance of Residual Tumor

BACKGROUND AND PURPOSE

Patients with surgically resected vestibular schwannoma will undergo multiple postoperative surveillance examinations, typically including postcontrast sequences. The purpose of this study was to compare high-resolution T2WI with gadolinium T1WI in the postoperative assessment of vestibular schwannoma.

MATERIALS AND METHODS

This was a retrospective study of patients with a history of resected vestibular schwannoma at a single institution. High-resolution T2WI and gadolinium T1WI were independently evaluated for residual disease. In addition, 3D and 2D measurements were performed in the group of patients with residual tumor. Statistical analysis was performed to evaluate the agreement between sequences on the binary assessment (presence/absence of tumor on initial postoperative examination) and to evaluate the equivalence of measurements for the 2 sequences on 3D and 2D quantitative assessment in individuals with residual disease.

RESULTS

One hundred forty-eight patients with retrosigmoid-approach resection of vestibular schwannomas were included in the final analysis. There was moderate-to-substantial agreement between the 2 sequences for the evaluation of the presence versus absence of tumor (Cohen κ coefficient = 0.78; 95% CI, 0.68-0.88). The 2 sequences were significantly equivalent for 2D and 3D quantitative assessments (short-axis P value = .021; long-axis P value = .015; 3D P value = .039).

CONCLUSIONS

In this retrospective study, we demonstrate moderate-to-substantial agreement in the categoric assessment for the presence versus absence of tumor and equivalence between the 2 sequences for both 2D and volumetric tumor measurements as performed in the subset of patients with measurable residual. On the basis of these results, high-resolution T2WI alone may be sufficient for early postoperative imaging surveillance in this patient population.

Paramaxillary CT-guided fine needle aspiration of head and neck lesions: technique, diagnostic yield, and safety profile

Computed tomography (CT)-guided percutaneous biopsy of deep-seated head and neck lesions can be a less invasive and equally effective alternative to surgical techniques. There are multiple approaches for needle biopsy that target varying spaces within the head and neck while successfully avoiding critical anatomy. In the paramaxillary approach, the needle is advanced through the infrazygomatic buccal space, in between the maxilla and mandible. In this study, we examine the safety and diagnostic yield of FNA without core needle biopsy performed via the paramaxillary approach in 19 patients yielding 20 fine needle aspirates between 2014 and 2022. Of the fine needle aspirates, 85.0% (17/20) were diagnostic. Concordant histopathologic diagnosis was obtained in 100% (17/17) diagnostic fine needle aspirates. There were no postprocedural complications.

Intraosseous Venous Malformations of the Head and Neck

Intraosseous venous malformations represent a subtype of venous vascular malformations that arise primarily in bone. In the head and neck, intraosseous venous malformations are most frequently found in the skull, skull base, and facial skeleton, with location at the geniculate ganglion of the facial nerve perhaps the most widely recognized. These non-neoplastic lesions are characterized by dilated venous channels with characteristic internal bony spicules on CT but may present with a more complex appearance on MR imaging and may share features with more aggressive lesions. Further confounding the imaging-based diagnosis of intraosseous venous malformation is the frequent misrepresentation of these lesions as hemangiomas in the radiology and clinical literature, as well as in daily practice. Because most intraosseous venous malformations can be left alone, their correct diagnosis may spare a patient unnecessary concern and intervention.

Benign bony tumors of the paranasal sinuses, orbit, and skull base

Benign bony tumors of the skull base and paranasal sinuses are uncommon entities, with an overall higher incidence in males. Benign bony tumors may lead to local expansion with resultant mass effect of potentially critical structures. Some benign bony tumors may undergo malignant transformation. This article reviews the presentation and management of benign bone tumors of the skull base and paranasal sinuses with special consideration to involvement of the adjacent orbit, intracranial and critical neurovascular structures. This review covers tumor incidence, location, gross and histologic appearance as well as radiographic findings, treatment, and recurrence rates. Tumors discussed in this article include osteochondromas, osteomas, osteoid osteomas, aneurysmal bone cysts, fibrous dysplasia, giant cell tumors, cemento-ossifying fibroma, ameloblastic fibro-odontoma, ecchordosis physaliphora, chondromyxoid fibroma, primary chronic osteomyelitis, primary chronic osteomyelitis, osteochondromyxoma, and dense bone islands.

Impingement of the Thyroid Cartilage on the Carotid Causing Clicking Larynx Syndrome and Stroke

We present the case of a patient with a recent history of ischemic stroke who presented with clicking larynx syndrome, a condition in which clicking noises in the larynx can be provoked by movement of the head and neck. Diagnostic imaging revealed unusual development and posterior angulation of the superior horn of the thyroid cartilage that potentially was causing trauma to the left common carotid artery. We deduced that symptomatic impingement of the carotid artery by the thyroid cartilage was not only the cause of the patient's clicking larynx syndrome, but also suspected to be the cause of her prior strokes due to repetitive trauma resulting in thrombus. The patient was managed surgically with thyroplasty and transcervical resection of the left greater cornu of the thyroid cartilage with resolution of her symptoms. Anatomical displacement of the thyroid cartilage can manifest as clicking larynx syndrome as well as cause mechanical injury to the carotid artery, resulting in turbulent flow, possible thrombosis, and stroke. Laryngoscope, 2021.

Interrater Reliability of NI-RADS on Posttreatment PET/Contrast-enhanced CT Scans in Head and Neck Squamous Cell Carcinoma

Purpose To evaluate the interrater reliability among radiologists examining posttreatment head and neck squamous cell carcinoma (HNSCC) fluorodeoxyglucose PET/contrast-enhanced CT (CECT) scans using Neck Imaging Reporting and Data System (NI-RADS). Materials and Methods In this retrospective study, images in 80 patients with HNSCC who underwent posttreatment surveillance PET/CECT and immediate prior comparison CECT or PET/CECT (from June 2014 to July 2016) were uploaded to the American College of Radiology's cloud-based website, Cortex. Eight radiologists from seven institutions with variable NI-RADS experience independently evaluated each case and assigned an appropriate prose description and NI-RADS category for the primary site and the neck site. Five of these individuals were experienced readers (> 5 years of experience), and three were novices (< 5 years of experience). In total, 640 lexicon-based and NI-RADS categories were assigned to lesions among the 80 included patients by the eight radiologists. Light generalization of Cohen κ for interrater reliability was performed. Results Of the 80 included patients (mean age, 63 years ± 10 [standard deviation]), there were 58 men (73%); 60 patients had stage IV HNSCC (75%), and the most common tumor location was oropharynx (n = 32; 40%). Light κ for lexicon was 0.30 (95% CI: 0.23, 0.36) at the primary site and 0.31 (95% CI: 0.24, 0.37) at the neck site. Light κ for NI-RADS category was 0.55 (95% CI: 0.46, 0.63) at the primary site and 0.60 (95% CI: 0.48, 0.69) at the neck site. Percent agreement between lexicon and correlative NI-RADS category was 84.4% (540 of 640) at the primary site and 92.6% (593 of 640) at the neck site. There was no significant difference in interobserver agreement among the experienced versus novice raters. Conclusion Moderate agreement was achieved among eight radiologists using NI-RADS at posttreatment HNSCC surveillance imaging. Keywords: CT, PET/CT, Head/Neck, Neck, Neoplasms-Primary, Observer Performance Supplemental material is available for this article. © RSNA, 2021.

Brain Imaging of Patients with COVID-19: Findings at an Academic Institution during the Height of the Outbreak in New York City

BACKGROUND AND PURPOSE

A large spectrum of neurologic disease has been reported in patients with coronavirus disease 2019 (COVID-19) infection. Our aim was to investigate the yield of neuroimaging in patients with COVID-19 undergoing CT or MR imaging of the brain and to describe associated imaging findings.

MATERIALS AND METHODS

We performed a retrospective cohort study involving 2054 patients with laboratory-confirmed COVID-19 presenting to 2 hospitals in New York City between March 4 and May 9, 2020, of whom 278 (14%) underwent either CT or MR imaging of the brain. All images initially received a formal interpretation from a neuroradiologist within the institution and were subsequently reviewed by 2 neuroradiologists in consensus, with disputes resolved by a third neuroradiologist.

RESULTS

The median age of these patients was 64 years (interquartile range, 50-75 years), and 43% were women. Among imaged patients, 58 (21%) demonstrated acute or subacute neuroimaging findings, the most common including cerebral infarctions (11%), parenchymal hematomas (3.6%), and posterior reversible encephalopathy syndrome (1.1%). Among the 51 patients with MR imaging examinations, 26 (51%) demonstrated acute or subacute findings; notable findings included 6 cases of cranial nerve abnormalities (including 4 patients with olfactory bulb abnormalities) and 3 patients with a microhemorrhage pattern compatible with critical illness-associated microbleeds.

CONCLUSIONS

Our experience confirms the wide range of neurologic imaging findings in patients with COVID-19 and suggests the need for further studies to optimize management for these patients.

Olfactory Bulb Signal Abnormality in Patients with COVID-19 Who Present with Neurologic Symptoms

BACKGROUND AND PURPOSE

Unique among the acute neurologic manifestations of Severe Acute Respiratory Syndrome coronavirus 2, the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic, is chemosensory dysfunction (anosmia or dysgeusia), which can be seen in patients who are otherwise oligosymptomatic or even asymptomatic. The purpose of this study was to determine if there is imaging evidence of olfactory apparatus pathology in patients with COVID-19 and neurologic symptoms.

MATERIALS AND METHODS

A retrospective case-control study compared the olfactory bulb and olfactory tract signal intensity on thin-section T2WI and postcontrast 3D T2 FLAIR images in patients with COVID-19 and neurologic symptoms, and age-matched controls imaged for olfactory dysfunction.

RESULTS

There was a significant difference in normalized olfactory bulb T2 FLAIR signal intensity between the patients with COVID-19 and the controls with anosmia (P = .003). Four of 12 patients with COVID-19 demonstrated intraneural T2 signal hyperintensity on postcontrast 3D T2 FLAIR compared with none of the 12 patients among the controls with anosmia (P = .028).

CONCLUSIONS

Olfactory bulb 3D T2 FLAIR signal intensity was greater in the patients with COVID-19 and neurologic symptoms compared with an age-matched control group with olfactory dysfunction, and this was qualitatively apparent in 4 of 12 patients with COVID-19. Analysis of these preliminary finding suggests that olfactory apparatus vulnerability to COVID-19 might be supported on conventional neuroimaging and may serve as a noninvasive biomarker of infection.

MON-LB45 Posterior Hypothalamic Involvement on Pre-Operative Magnetic Resonance Imaging as a Predictor for Hypothalamic Obesity in Craniopharyngiomas

Craniopharyngioma (CP) is a rare embryonic tumor of the sellar and parasellar region with benign histology (World Health Organization grade I) thought to arise from embryonic remnants of Rathke’s pouch. Despite its high survival rates, this tumor can lead to severe morbidity secondary to destruction of adjacent structures. Hypothalamus (HT) is a brain region that has a central role in regulating body weight through a complex mechanism involving central and peripheral signaling pathways. Destruction of its distinctive nuclei induces hyperphagia, hyperinsulinemia and weight gain. Seventy-five patients with CP who underwent first surgical resection in a single center by the same neurosurgeon between February 2005 and March 2019 were screened; those who have had prior radiation, were aged below 18 years, or did not have follow up body mass index (BMI) after surgery were excluded. Ultimately, this study included 45 patients with a mean age 50.5 years, 73.3% women. Pre and post-operative MRI were independently reviewed by three neuroradiologists to determine involvement of the hypothalamic regions: anterior, anterior and posterior, or no hypothalamic involvement. Body mass index were recorded pre operatively and subsequently after TSS up to 24 months post operation. Association between hypothalamic region involvement and BMI as well as endocrine function were examined. Posterior hypothalamic involvement seen in pre operative MRI (N=28) was significantly associated with higher BMI at 3-6 month, 7-12 month, and 13-24 month follow up (p < 0.05) in comparison to involvement of anterior hypothalamic alone or no hypothalamic involvement. Similarly, posterior hypothalamic involvement in the pre and post-operative MRI was significantly associated with development of diabetes insipidus (DI) (p < 0.05) compared to anterior or no hypothalamic involvement. There was no association between pre-operative BMI and hypothalamic involvement. Although the weight gain was accelerated after surgery, there was no association between post operative MRI and ensuing BMI, suggesting that the damage of the hypothalamic nuclei was done by the CP rather than surgical procedure. Conclusion: Assessment of hypothalamic involvement by anterior and posterior regions on pre operative MRI can be helpful in predicting development of obesity in patients with CP.

From the Eye of the Storm: Multi-Institutional Practical Perspectives on Neuroradiology from the COVID-19 Outbreak in New York City

During the Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) pandemic, neuroradiology practices have experienced a paradigm shift in practice, which affected everything from staffing, workflow, work volumes, conferences, resident and fellowship education, and research. This article highlights adaptive strategies that were undertaken at the epicenter of the outbreak in New York City during the past 4-6 weeks, as experienced by 5 large neuroradiology academic departments.

Imaging Review of New and Emerging Sinonasal Tumors and Tumor-Like Entities from the Fourth Edition of the World Health Organization Classification of Head and Neck Tumors

The sinonasal tract is an environment diverse with neoplasia. Given the continued discovery of entities generally specific to the sinonasal tract, the fourth edition of the World Health Organization Classification of Head and Neck Tumors was released in 2017. It describes 3 new, well-defined entities and several less-defined, emerging entities. The new entities are seromucinous hamartomas, nuclear protein in testis carcinomas, and biphenotypic sinonasal sarcomas. Emerging entities include human papillomavirus-related sinonasal carcinomas, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1-deficient sinonasal carcinomas, renal cell-like adenocarcinomas, and chondromesenchymal hamartomas. The literature thus far largely focuses on the pathology of these entities. Our goal in this report was to familiarize radiologists with these new diagnoses and to provide available information regarding their imaging appearances.

Beals syndrome with middle and inner ear dysplasia and encephalocele: A case report and review of imaging findings

A 10-year-old male with history of Beals syndrome presented with hearing loss and was found to have middle and inner ear dysplasia and left temporal encephalocele on imaging. Beals syndrome is a rare autosomal dominant connective tissue disorder caused by a mutation in the fibrillin-2 gene. Skeletal manifestations of Beals have been reported, including anomalies of the long bones, calvarium, and spine. External ear abnormalities with "crumpled ear" deformity are seen in the majority of patients. This is the first case to report imaging findings of the middle and inner ear in a patient with Beals.

Endonasal endoscopic transsphenoidal resection of intrinsic third ventricular craniopharyngioma: surgical results

OBJECTIVE

Intrinsic third ventricular craniopharyngiomas (IVCs) have been reported by some authors to "pose the greatest surgical challenge" of all craniopharyngiomas (CPAs). A variety of open microsurgical approaches have historically been used for resection of these tumors. Despite increased utilization of the endoscopic endonasal approach (EEA) for resection of CPAs in recent years, many authors continue to recommend against use of the EEA for resection of IVCs. In this paper, the authors present the largest series to date utilizing the EEA to remove IVCs.

METHODS

The authors reviewed a prospectively acquired database of the EEA for resection of IVCs over 14 years at Weill Cornell Medical College, NewYork-Presbyterian Hospital. Preoperative MR images were examined independently by two neurosurgeons and a neuroradiologist to identify IVCs. Pre- and postoperative endocrinological, ophthalmological, radiographic, and other morbidities were determined from retrospective chart review and volumetric radiographic analysis.

RESULTS

Between January 2006 and August 2017, 10 patients (4 men, 6 women) ranging in age from 26 to 67 years old, underwent resection of an IVC utilizing the EEA. Preoperative endocrinopathy was present in 70% and visual deterioration in 60%. Gross-total resection (GTR) was achieved in 9 (90%) of 10 patients, with achievement of near-total (98%) resection in the remaining patient. Pathology was papillary in 30%. Closure incorporated a "gasket-seal" technique with nasoseptal flap coverage and either lumbar drainage (9 patients) or a ventricular drain (1 patient). Postoperatively, complete anterior and posterior pituitary insufficiency was present in 90% and 70% of patients, respectively. In 4 patients with normal vision prior to surgery, 3 had stable vision following tumor resection. One patient noted a new, incongruous, left inferior homonymous quadrantanopsia postoperatively. In the 6 patients who presented with compromised vision, 2 reported stable vision following surgery. Each of the remaining 4 patients noted significant improvement in vision after tumor resection, with complete restoration of normal vision in 1 patient. Aside from the single case (10%) of visual deterioration referenced above, there were no instances of postoperative neurological decline. Postoperative CSF leakage occurred in 1 morbidly obese patient who required reoperation for revision of closure. After a mean follow-up of 46.8 months (range 4-131 months), tumor recurrence was observed in 2 patients (20%), one of whom was treated with radiation and the other with chemotherapy. Both of these patients had previously undergone GTR of the IVC.

CONCLUSIONS

The 10 patients described in this report represent the largest number of patients with IVC treated using EEA for resection to date. EEA for resection of IVC is a safe and efficacious operative strategy that should be considered a surgical option in the treatment of this challenging subset of tumors.

Rapid detection of Listeria monocytogenes rhombencephalitis in an immunocompetent patient by multiplexed PCR

A 46-year-old previously healthy man presented with 1 week of headache, nausea, vomiting and dizziness. He was found to have cranial nerve deficits, his cerebrospinal fluid (CSF) demonstrated a lymphocytic pleocytosis and brain MRI suggested rhombencephalitis. Although Gram stains and cultures of his CSF did not identify a pathogen, Listeria monocytogenes DNA was detected by the FilmArray Meningitis/Encephalitis panel within 2 hours of performing a lumbar puncture. He was treated with ampicillin and gentamicin and had a near-complete recovery. This case highlights the importance of recognising L. monocytogenes infection as a cause of acute cranial nerve impairment with MRI findings suggestive of brainstem encephalitis. It also highlights the frequently atypical CSF profile and low yield of culture in L. monocytogenes rhombencephalitis and the value of multiplex PCR testing of CSF to rapidly identify this pathogen and permit targeted therapy.

Prognostic Implications of Gadolinium Enhancement of Skull Base Chordomas

BACKGROUND AND PURPOSE

Skull base chordomas often demonstrate variable MR imaging characteristics, and there has been limited prior research investigating the potential clinical relevance of this variability. The purpose of this retrospective study was to assess the prognostic implications of signal intensity on standard imaging techniques for the biologic behavior of skull base chordomas.

MATERIALS AND METHODS

Medical records were retrospectively reviewed for 22 patients with pathologically confirmed skull base chordomas. Clinical data were recorded, including the degree of surgical resection, the presence or absence of radiation therapy, and time to progression/recurrence of the tumor or time without progression/recurrence of the tumor following initial treatment. Pretreatment imaging was reviewed for the presence or absence of enhancement and the T2 signal characteristics. Tumor-to-brain stem signal intensity ratios on T2, precontrast T1, and postcontrast T1 spin-echo sequences were also calculated. Statistical analysis was then performed to assess correlations between imaging characteristics and tumor progression/recurrence.

RESULTS

Progression/recurrence of skull base chordomas was seen following surgical resection in 11 of 14 (78.6%) patients with enhancing tumors and in zero of 8 patients with nonenhancing tumors. There was a statistically significant correlation between skull base chordoma enhancement and subsequent tumor progression/recurrence (P < .001), which remained significant after controlling for differences in treatment strategy (P < .001). There was also a correlation between postcontrast T1 signal intensity (as measured by postcontrast T1 tumor-to-brain stem signal intensity ratios) and recurrence/progression (P = .02). While T2 signal intensity was higher in patients without tumor progression (median tumor-to-brain stem signal intensity ratios on T2 = 2.27) than in those with progression (median tumor-to-brain stem signal intensity ratios on T2 = 1.78), this association was not significant (P = .12).

CONCLUSIONS

Enhancement of skull base chordomas is a risk factor for tumor progression/recurrence following surgical resection.

Protrusion of the Infraorbital Nerve into the Maxillary Sinus on CT: Prevalence, Proposed Grading Method, and Suggested Clinical Implications

BACKGROUND AND PURPOSE

The infraorbital nerve arises from the maxillary branch of the trigeminal nerve and normally traverses the orbital floor in the infraorbital canal. Sometimes, however, the infraorbital canal protrudes into the maxillary sinus separate from the orbital floor. We systematically studied the prevalence of this variant.

MATERIALS AND METHODS

We performed a retrospective review of 500 consecutive sinus CTs performed at our outpatient centers. The infraorbital nerve protruded into the maxillary sinus if the entire wall of the infraorbital canal was separate from the walls of the sinus. We recorded the length of the bony septum that attached the infraorbital canal to the wall of the maxillary sinus and noted whether the protrusion was bilateral. We also measured the distance from the inferior orbital rim where the infraorbital canal begins to protrude into the sinus.

RESULTS

There was a prevalence of 10.8% for infraorbital canal protrusion into the maxillary sinus and 5.6% for bilateral protrusion. The median length of the bony septum attaching the infraorbital canal to a maxillary sinus wall, which was invariably present, was 4 mm. The median distance at which the infraorbital nerve began to protrude into the sinus was 11 mm posterior to the inferior orbital rim.

CONCLUSIONS

Although this condition has been reported in only 3 patients previously, infraorbital canal protrusion into the maxillary sinus was present in >10% of our cohort. Identification of this variant on CT could help a surgeon avoid patient injury.

Parry Romberg Syndrome: 7 Cases and Literature Review

Parry Romberg syndrome is a rare progressive hemiatrophy of the face that typically occurs in children and young adults and has a peculiar progression that ceases without apparent cause after a highly variable period. Only a subset of patients with Parry Romberg syndrome will develop secondary neurologic or ophthalmologic symptoms, and prognosis is highly variable. Inconsistency in the pattern of atrophy and the development of associated symptoms in patients with Parry Romberg syndrome has made it challenging to diagnose, prognosticate, and treat. The precise etiology of this disease remains unknown, but some authors have implicated sympathetic cervical ganglion dysfunction, abnormal embryogenesis, autoimmune and inflammatory mechanisms, or vasculopathy as potential causes. We present 7 cases of Parry Romberg syndrome and their associated clinical and imaging findings with specific attention to the radiographic characteristics of this disease.

Comparison of the upper airway dynamics of oronasal and nasal masks with positive airway pressure treatment using cine magnetic resonance imaging

PURPOSE

It is known that oronasal masks are not as effective at opening the upper airway compared to nasal only continuous positive airway pressure (CPAP) masks in patients with sleep-disordered breathing. However, the physiological mechanism for this difference in efficacy is not known; although, it has been hypothesized to involve the retroglossal and/or retropalatal region of the upper airway. The objective of this study was to investigate differences in retroglossal and retropalatal anterior-posterior space with the use of oronasal vs. nasal CPAP masks using real-time cine magnetic resonance imaging (cMRI).

METHODS

Ten subjects (eight men, two women) with obstructive sleep apnea (OSA) were given cMRI with both nasal and oronasal CPAP masks. Each subject was imaged with each interface at pressures of 5, 10, and 15 cm of H2O, while in the supine position along the sagittal plane.

RESULTS

The oronasal mask produced significantly less airway opening in the retropalatal region of the upper airway compared to the nasal mask interface. During exhalation, mask style had a significant effect on anterior-posterior distance p = 0.016. No differences were found in the retroglossal region between mask styles.

CONCLUSIONS

Our study confirmed previous findings showing differences in treatment efficacy between oronasal and nasal mask styles. We have shown anatomic evidence that the nasal mask is more effective in opening the upper airway compared to the oronasal mask in the retropalatal region.

Temporal bone imaging

Temporal bone imaging is performed for a variety of clinical conditions addressed in the outpatient and acute care setting ranging from hearing loss to trauma. Recent advances in magnetic resonance technology have enhanced the assessment of fine anatomic temporal bone detail and improved the diagnostic sensitivity for important pathology. For example, non-echo planar diffusion weighted imaging increases detection rate and diagnostic confidence of recurrent cholesteatoma. This chapter will focus on relevant temporal bone clinical entities and new MR developments that have come into clinical practice.

Clinical Practice Guideline

The American Academy of Otolaryngology—Head and Neck Surgery Foundation (AAO-HNSF) has published a supplement to this issue featuring the new Clinical Practice Guideline: Tinnitus. To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose, and key action statements. The 13 recommendations developed address the evaluation of patients with tinnitus, including selection and timing of diagnostic testing and specialty referral to identify potential underlying treatable pathology. It will then focus on the evaluation and treatment of patients with persistent primary tinnitus, with recommendations to guide the evaluation and measurement of the impact of tinnitus and to determine the most appropriate interventions to improve symptoms and quality of life for tinnitus sufferers.

Clinical Practice Guideline

Objective

Tinnitus is the perception of sound without an external source. More than 50 million people in the United States have reported experiencing tinnitus, resulting in an estimated prevalence of 10% to 15% in adults. Despite the high prevalence of tinnitus and its potential significant effect on quality of life, there are no evidence-based, multidisciplinary clinical practice guidelines to assist clinicians with management. The focus of this guideline is on tinnitus that is both bothersome and persistent (lasting 6 months or longer), which often negatively affects the patient’s quality of life. The target audience for the guideline is any clinician, including nonphysicians, involved in managing patients with tinnitus. The target patient population is limited to adults (18 years and older) with primary tinnitus that is persistent and bothersome.

Purpose

The purpose of this guideline is to provide evidence-based recommendations for clinicians managing patients with tinnitus. This guideline provides clinicians with a logical framework to improve patient care and mitigate the personal and social effects of persistent, bothersome tinnitus. It will discuss the evaluation of patients with tinnitus, including selection and timing of diagnostic testing and specialty referral to identify potential underlying treatable pathology. It will then focus on the evaluation and treatment of patients with persistent primary tinnitus, with recommendations to guide the evaluation and measurement of the effect of tinnitus and to determine the most appropriate interventions to improve symptoms and quality of life for tinnitus sufferers.

Action Statements

The development group made a strong recommendation that clinicians distinguish patients with bothersome tinnitus from patients with nonbothersome tinnitus. The development group made a strong recommendation against obtaining imaging studies of the head and neck in patients with tinnitus, specifically to evaluate tinnitus that does not localize to 1 ear, is nonpulsatile, and is not associated with focal neurologic abnormalities or an asymmetric hearing loss. The panel made the following recommendations: Clinicians should (a) perform a targeted history and physical examination at the initial evaluation of a patient with presumed primary tinnitus to identify conditions that if promptly identified and managed may relieve tinnitus; (b) obtain a prompt, comprehensive audiologic examination in patients with tinnitus that is unilateral, persistent (≥ 6 months), or associated with hearing difficulties; (c) distinguish patients with bothersome tinnitus of recent onset from those with persistent symptoms (≥ 6 months) to prioritize intervention and facilitate discussions about natural history and follow-up care; (d) educate patients with persistent, bothersome tinnitus about management strategies; (e) recommend a hearing aid evaluation for patients who have persistent, bothersome tinnitus associated with documented hearing loss; and (f) recommend cognitive behavioral therapy to patients with persistent, bothersome tinnitus. The panel recommended against (a) antidepressants, anticonvulsants, anxiolytics, or intratympanic medications for the routine treatment of patients with persistent, bothersome tinnitus; (b) Ginkgo biloba, melatonin, zinc, or other dietary supplements for treating patients with persistent, bothersome tinnitus; and (c) transcranial magnetic stimulation for the routine treatment of patients with persistent, bothersome tinnitus. The development group provided the following options: Clinicians may (a) obtain an initial comprehensive audiologic examination in patients who present with tinnitus (regardless of laterality, duration, or perceived hearing status); and (b) recommend sound therapy to patients with persistent, bothersome tinnitus. The development group provided no recommendation regarding the effect of acupuncture in patients with persistent, bothersome tinnitus.

Mechanics of circular breathing in wind musicians using cine magnetic resonance imaging techniques

OBJECTIVES/HYPOTHESIS

To investigate the mechanics of circular breathing using cine magnetic resonance imaging (cMRI).

STUDY DESIGN

Pilot study.

METHODS

Eight musicians were asked to sustain a note by circular breathing while being studied inside a Siemens Trio 3T magnetic resonance imaging scanner. Subjects were imaged in the midsagittal plane using an innovative T1-weighted cMRI. Our study population included six professionals and two experienced amateurs (two saxophonists, two trombonists, and four trumpeters). Five predetermined oropharyngeal distances were measured frame by frame. Data were analyzed for displacement and percentage change over time. Oral airway area was measured using automated bounding box techniques.

RESULTS

All subjects were observed to complete the same series of steps characterized by 1) superior/posterior tongue displacement, 2) inferior/anterior soft palate displacement, 3) anterior tongue/soft palate displacement, 4) superior/posterior soft palate displacement, and 5) return of the tongue to baseline. Posterior oropharyngeal occlusion was demonstrated in bounding box data. Relative occlusion time was significantly longer among experienced amateurs than professionals (P = .01), with a similar trend in absolute occlusion time (P = .08). A trend toward a longer circular breathing cycle time was observed among saxophonists and trumpeters (P = .2), although the difference among trumpeters disappeared when amateurs were excluded.

CONCLUSIONS

Circular breathing has been investigated as therapy for obstructive sleep apnea. This study defines the mechanics of circular breathing for use in training--and potentially in therapy--if proven useful. We demonstrated similar mechanics across subgroups, and increased efficiency among professionals. Our findings demonstrate the feasibility and reliability of cMRI in the dynamic assessment of oropharyngeal motion.

LEVEL OF EVIDENCE

NA.

Global population structure and demographic history of the grey seal

Although the grey seal Halichoerus grypus is one of the most familiar and intensively studied of all pinniped species, its global population structure remains to be elucidated. Little is also known about how the species as a whole may have historically responded to climate-driven changes in habitat availability and anthropogenic exploitation. We therefore analysed samples from over 1500 individuals collected from 22 colonies spanning the Western and Eastern Atlantic and the Baltic Sea regions, represented by 350 bp of the mitochondrial hypervariable region and up to nine microsatellites. Strong population structure was observed at both types of marker, and highly asymmetrical patterns of gene flow were also inferred, with the Orkney Islands being identified as a source of emigrants to other areas in the Eastern Atlantic. The Baltic and Eastern Atlantic regions were estimated to have diverged a little over 10 000 years ago, consistent with the last proposed isolation of the Baltic Sea. Approximate Bayesian computation also identified genetic signals consistent with postglacial population expansion across much of the species range, suggesting that grey seals are highly responsive to changes in habitat availability.

Chiasmitis caused by Mycobacterium haemophilum in an immunocompromised adult

We report a case of chiasmitis caused by a rare nontuberculous mycobacterium in an immunocompromised patient. A 44-year-old man with a history of AIDS presented with recurrent vision loss and headache. Magnetic resonance imaging (MRI) demonstrated an enhancing mass involving the optic chiasm. Histopathologic and microbiological evaluation revealed infection with Mycobacterium haemophilum. While combination antimicrobial and steroid therapy contributed to improvement in his vision, the patient's symptoms recurred. Follow-up MRI showed extension of infection to the hypothalamus and leptomeninges, indicative of basilar meningitis. MRI is a valuable tool for early diagnosis of chiasmitis as well as for monitoring infection progression and treatment response.

How to perform parathyroid 4D CT: tips and traps for technique and interpretation

Parathyroid four-dimensional (4D) computed tomography (CT) is an imaging technique for preoperative localization of parathyroid adenomas that involves multidetector CT image acquisition during two or more contrast enhancement phases. Four-dimensional CT offers an alternative or additional tool in the evaluation of primary hyperparathyroidism. The purpose of this article is to describe the 4D CT technique and provide a practical guide to the radiologist for imaging interpretation. The article will discuss the rationale for imaging, approach to interpretation, imaging findings, and pitfalls.

Molecular insights into the historic demography of bowhead whales: understanding the evolutionary basis of contemporary management practices

Patterns of genetic variation observed within species reflect evolutionary histories that include signatures of past demography. Understanding the demographic component of species' history is fundamental to informed management because changes in effective population size affect response to environmental change and evolvability, the strength of genetic drift, and maintenance of genetic variability. Species experiencing anthropogenic population reductions provide valuable case studies for understanding the genetic response to demographic change because historic changes in the census size are often well documented. A classic example is the bowhead whale, Balaena mysticetus, which experienced dramatic population depletion due to commercial whaling in the late 19th and early 20th centuries. Consequently, we analyzed a large multi-marker dataset of bowhead whales using a variety of analytical methods, including extended Bayesian skyline analysis and approximate Bayesian computation, to characterize genetic signatures of both ancient and contemporary demographic histories. No genetic signature of recent population depletion was recovered through any analysis incorporating realistic mutation assumptions, probably due to the combined influences of long generation time, short bottleneck duration, and the magnitude of population depletion. In contrast, a robust signal of population expansion was detected around 70,000 years ago, followed by a population decline around 15,000 years ago. The timing of these events coincides to a historic glacial period and the onset of warming at the end of the last glacial maximum, respectively. By implication, climate driven long-term variation in Arctic Ocean productivity, rather than recent anthropogenic disturbance, appears to have been the primary driver of historic bowhead whale demography.

Variability in the position of the retropharyngeal internal carotid artery

The retropharyngeal internal carotid artery (ICA) is a well-described arterial anomaly with important implications for patients undergoing pharyngeal approach surgical procedures. Existing clinical and imaging classification schemes for a retropharyngeal ICA take into account arterial distance to the pharyngeal mucosal wall. We describe a case of mobility of a retropharyngeal ICA between short-interval imaging studies. The possibility of respiratory variability or other etiologies causing such changes in retropharyngeal carotid position have not been described previously. Our findings suggest that imaging findings from a single study alone may not be sufficient to confidently exclude this clinically significant arterial anomaly.

Diagnostic accuracy of 4D-CT for parathyroid adenomas and hyperplasia

BACKGROUND AND PURPOSE

4D-CT is a novel method of multiphase CT imaging. When used to localize parathyroid adenomas and hyperplasia, this technique may allow for more robust diagnostic accuracy than traditional sonography and nuclear scintigraphy techniques. The purpose of our study is to assess the accuracy of 4D-CT for localizing pathologically proved parathyroid adenomas and hyperplasia found during surgery.

MATERIALS AND METHODS

A total of 35 pathologically proved cases of parathyroid adenoma and hyperplasia were retrospectively reviewed between January 2009 and March 2011. Inclusion criteria were availability of final surgical pathology and performance of preoperative 4D-CT. No cases were excluded. Sensitivity, specificity, and accuracy of 4D-CT were ascertained including both the side and quadrant of the pathologically proved lesion.

RESULTS

Of the 35 pathologically proved cases collected over the study period, 32 (sensitivity = 91%) patients were found positive for parathyroid disease using 4D-CT, including 3 cases of multigland disease. For lateralization of single-gland disease, 4D-CT demonstrated an accuracy of 93%. 4D-CT revealed a suboptimal 44% sensitivity, but 100% specificity, for multigland disease.

CONCLUSIONS

4D-CT demonstrated a high diagnostic accuracy for single and multigland disease in our cohort. Importantly, 4D-CT accurately lateralized single-gland adenomas in >90% of cases, allowing the surgeon to employ a directed operative approach. 4D-CT also showed a very high specificity for the detection of multigland disease.

Bayesian inference of a historical bottleneck in a heavily exploited marine mammal

Emerging Bayesian analytical approaches offer increasingly sophisticated means of reconstructing historical population dynamics from genetic data, but have been little applied to scenarios involving demographic bottlenecks. Consequently, we analysed a large mitochondrial and microsatellite dataset from the Antarctic fur seal Arctocephalus gazella, a species subjected to one of the most extreme examples of uncontrolled exploitation in history when it was reduced to the brink of extinction by the sealing industry during the late eighteenth and nineteenth centuries. Classical bottleneck tests, which exploit the fact that rare alleles are rapidly lost during demographic reduction, yielded ambiguous results. In contrast, a strong signal of recent demographic decline was detected using both Bayesian skyline plots and Approximate Bayesian Computation, the latter also allowing derivation of posterior parameter estimates that were remarkably consistent with historical observations. This was achieved using only contemporary samples, further emphasizing the potential of Bayesian approaches to address important problems in conservation and evolutionary biology.

Carcinoid tumor metastases to the extraocular muscles: MR imaging and CT findings and review of the literature

Although a relatively rare neoplasm, primary carcinoid tumor has an unusual propensity to metastasize to the orbits. Within the orbit, metastatic EOM lesions have been described in scattered reports in the ophthalmology literature but have received little to no attention in the radiology literature. After a retrospective review, we identified CT and MR imaging studies of 7 patients with carcinoid tumor metastatic to the EOM. Our findings suggest that in patients with known carcinoid tumor, well-defined, round, or fusiform masses of the EOM should strongly suggest metastatic involvement. Our series suggests that bilateral lesions may occur and that any EOM can be involved. Knowledge of this pattern of metastatic disease may spare biopsies in some patients, and with current orbit-sparing therapy for patients with localized orbital disease, early and accurate diagnosis can significantly improve patient outcomes.

Magnetic resonance imaging of carotid atherosclerotic plaque in clinically suspected acute transient ischemic attack and acute ischemic stroke

BACKGROUND

Carotid atherosclerotic plaque rupture is thought to cause transient ischemic attack (TIA) and ischemic stroke (IS). Pathological hallmarks of these plaques have been identified through observational studies. Although generally accepted, the relationship between cerebral thromboembolism and in situ atherosclerotic plaque morphology has never been directly observed noninvasively in the acute setting.

METHODS AND RESULTS

Consecutive acutely symptomatic patients referred for stroke protocol magnetic resonance imaging/angiography underwent additional T1- and T2-weighted carotid bifurcation imaging with the use of a 3-dimensional technique with blood signal suppression. Two blinded reviewers performed plaque gradings according to the American Heart Association classification system. Discharge outcomes and brain magnetic resonance imaging results were obtained. Image quality for plaque characterization was adequate in 86 of 106 patients (81%). Eight TIA/IS patients with noncarotid pathogenesis were excluded, yielding 78 study patients (38 men and 40 women with a mean age of 64.3 years, SD 14.7) with 156 paired watershed vessel/cerebral hemisphere observations. Thirty-seven patients had 40 TIA/IS events. There was a significant association between type VI plaque (demonstrating cap rupture, hemorrhage, and/or thrombosis) and ipsilateral TIA/IS (P<0.001). A multiple logistic regression model including standard Framingham risk factors and type VI plaque was constructed. Type VI plaque was the dominant outcome-associated observation achieving significance (P<0.0001; odds ratio, 11.66; 95% confidence interval, 5.31 to 25.60).

CONCLUSIONS

In situ type VI carotid bifurcation region plaque identified by magnetic resonance imaging is associated with ipsilateral acute TIA/IS as an independent identifier of events, thereby supporting the dominant disease pathophysiology.

Imaging of the facial nerve

A variety of congenital, traumatic, vascular, inflammatory, and neoplastic processes may affect the facial nerve. Prudent use of CT and MR imaging combined with a complete understanding of facial nerve anatomy helps in narrowing the differential diagnosis. The precise anatomic course of the facial nerve must be charted in patients who undergo middle ear surgery. Also of great importance is recognition of the fact that the facial nerve may be affected in cancers of the head and neck by perineural spread. This article reviews the anatomy of the facial nerve and relevant, current clinical evaluation and imaging strategies.