Joseph M. Hoxworth

The Role of Digital Subtraction Myelography in the Diagnosis and Localization of Spontaneous Spinal CSF Leaks

OBJECTIVE The objective of our study was to review the clinical utility of digital subtraction myelography for the diagnosis of spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH) and those with superficial siderosis. MATERIALS AND METHODS Procedure logs from 2007 to 2011 were reviewed to identify cases in which digital subtraction myelography was performed to diagnose spinal CSF leaks. Electronic medical records were reviewed to obtain information regarding diagnosis and outcome. For patients to be included in the study, preprocedural spinal MRI had to show an extradural fluid collection spanning more than one vertebral level and postmyelographic CT had to confirm the presence of an active CSF leak. If digital subtraction myelography successfully showed the site of the CSF leak, the location was documented. RESULTS Eleven patients (seven men and four women; mean age, 49.0 years) underwent digital subtraction myelography during the study period. Six patients had SIH and five patients had superficial siderosis. The extradural fluid collection on spinal MRI averaged a length of 15.5 vertebral levels. Digital subtraction myelography successfully showed the site of the CSF leak in nine of the 11 patients, and all of the dural tears were located in the thoracic spine between T3 and T11. CONCLUSION Digital subtraction myelography is a valuable diagnostic tool for the localization of rapid spinal CSF leaks and should be considered in patients who are clinically suspected to have a dural tear that is accompanied by a longitudinally extensive extradural fluid collection on spinal MRI.

Lymphoepithelioma-like carcinoma of the lung: radiologic features of an uncommon primary pulmonary neoplasm.

OBJECTIVE The purpose of this study was to review the chest radiographic, CT, and MRI appearances of primary pulmonary lymphoepithelioma-like carcinoma (LELC). CONCLUSION Primary pulmonary LELC is histopathologically identical to nasopharyngeal carcinoma. The radiographic, CT, and MRI features of primary pulmonary LELC are nonspecific, often resembling those of bronchogenic carcinoma. Primary pulmonary LELC usually presents as a poorly circumscribed, enhancing, peripheral solitary pulmonary nodule on CT; necrosis may be present and is considered a poor prognostic sign. MRI shows isointense to low-intensity signal on T1-weighted images and mildly increased signal on T2-weighted images; enhancement of abnormal tissue is typical. Most patients present with early-stage disease. Primary pulmonary LELC should be suspected in selected patients and requires differentiation from bronchogenic carcinoma and metastatic nasopharyngeal carcinoma.

Ultrafast dynamic computed tomography myelography for the precise identification of high-flow cerebrospinal fluid leaks caused by spiculated spinal osteophytes

OBJECT Precise localization and understanding of the origin of spontaneous high-flow spinal CSF leaks is required prior to targeted treatment. This study demonstrates the utility of ultrafast dynamic CT myelography for the precise localization of high-flow CSF leaks caused by spiculated spinal osteophytes. METHODS This study reports a series of 14 patients with high-flow CSF leaks caused by spiculated spinal osteophytes who underwent ultrafast dynamic CT myelography between March 2009 and December 2010. There were 10 male and 4 female patients, with an average age of 49 years (range 37-74 years). The value of ultrafast dynamic CT myelography in depicting the CSF leak site was qualitatively assessed. RESULTS In all 14 patients, ultrafast dynamic CT myelography was technically successful at precisely demonstrating the site of the CSF leak, the causative spiculated osteophyte piercing the dura, and the relationship of the implicated osteophyte to adjacent structures. Leak sites included 3 cervical, 11 thoracic, and 0 lumbar levels, with 86% of the leaks occurring from C-5 to T-7. Information obtained from the ultrafast dynamic CT myelogram was considered useful in all treated CSF leaks. CONCLUSIONS Spinal osteophytes piercing the dura are a more frequent cause of high-flow CSF leaks than previously recognized. Ultrafast dynamic CT myelography adds value beyond standard dynamic myelography or digital subtraction myelography in the diagnosis and anatomical characterization of high-flow spinal CSF leaks caused by these osteophytes. This information allows for appropriate planning for percutaneous or surgical treatment.

Sinonasal phosphaturic mesenchymal tumor: Case report and systematic review.

We report a case of sinonasal phosphaturic mesenchymal tumor (PMT) and conduct a systematic review of the literature to highlight a unique paraneoplastic syndrome associated with PMT. We used English language publications from Medline and Cochrane databases (1970–2013) as data sources. A systematic review of the literature was conducted. All reported cases of head and neck PMTs were included. The presence or absence of the associated paraneoplastic syndrome was noted. We found 33 cases of PMT in the head and neck reported in the literature, 17 of which occurred in the sinonasal area. Approximately 5% of all PMTs are located in the head and neck. Just greater than half are concentrated in the sinonasal area, and the remaining involve various bony and soft tissue structures of the head and neck. PMT is sometimes associated with a paraneoplastic syndrome of tumor-induced (oncogenic) osteomalacia (TIO) causing bone pain, muscle weakness, and pathologic fractures. We present the 18th reported case of sinonasal PMT. A smooth mucosa-covered midline intraseptal mass filling the posterior nasal cavity with destruction and erosion of the skull base was found in an adult male. The patient underwent successful endoscopic resection with wide negative margins and is without recurrence at 24-month follow-up. PMT is a benign, locally aggressive tumor with rare malignant transformation. Knowledge of the bony invasion and destruction caused by this tumor is essential in planning surgical resection with wide negative margins. Familiarity with the associated TIO is essential to investigate for and manage any associated bony morbidity.

Inferior vena cava thrombosis after transjugular intrahepatic portosystemic shunt revision with a covered stent

A 42-year-old woman who had undergone multiple revisions of a bare-stent transjugular intrahepatic portosystemic shunt was treated for in-stent stenosis by insertion of a polytetrafluoroethylene (PTFE)-covered stent. Immediately after revision with the covered stent, she developed inferior vena cava (IVC) thrombosis. The potential causes and implications of this complication are discussed.

Measurement of cochlear length using the ‘A' value for cochlea basal diameter: A feasibility study†

Objectives: To determine whether the cochlea basal diameter (A value) measurement can be consistently and precisely obtained from high-resolution temporal bone imaging for use in cochlear length estimation. Methods: A feasibility study at a tertiary referral center was performed using the temporal bone CTs of 40 consecutive patients. The distance from the round window to the lateral wall was measured for each cochlea by two independent reviewers, a neuroradiologist and an otolaryngologist. The interrater reliability was calculated using the intraclass correlation coefficient (ICC) and the Bland–Altman plot. Results: Forty patients (19 males, 21 females) for a total of 80 cochleae were included. Interrater reliability on the same ear had a high level of agreement by both the ICC and the Bland–Altman plot. ICCs were 0.90 (95% CI: 0.82, 0.94) for the left ear and 0.96 (95% CI: 0.92, 0.98) for the right ear. Bland–Altman plot confirmed interrater reliability with all 96% of measurements falling within the 95% limits of agreement. Conclusions: Measurement between the round window and lateral cochlear wall can be consistently and reliably obtained from high-resolution temporal bone CT scans. Thus, it is feasible to utilize this method to estimate the cochlear length of patients undergoing cochlear implantation.

Diagnosing Large Vestibular Aqueduct: Radiological Review of High-Resolution CT Versus High-Resolution Volumetric MRI

OBJECTIVES To compare the diagnostic yield of high-resolution volumetric T2-weighted MRI (HRT2-MRI) with high-resolution computed tomography (HRCT) for diagnosis of large vestibular aqueduct (LVA). STUDY DESIGN Three board-certified neuroradiologists performed an independent, blinded radiological review for diagnosing LVA with 2:1 age-matched controls on patients with both HRCT and HRT2-MRI imaging. SETTING Tertiary referral center. PATIENTS All patients between 2002 and 2016 with hearing loss who underwent both HRCT and HRT2-MRI and were diagnosed with LVA on either modality. MAIN OUTCOME MEASURES Concordance rate for LVA between HRCT and HRT2-MRI. RESULTS Concordance rate for HRCT and HRT2-MRI for diagnosing LVA was 88% (124/141) when assessing both the midpoint and external aperture diameters. Fifteen ears had LVA on computed tomography (CT), but not on magnetic resonance imaging (MRI); in comparison, two ears had LVA on MRI, but not on CT (p = 0.002). Excellent inter-rater reliability among the three radiologists was demonstrated. CONCLUSION Historically, HRCT has been the imaging modality of choice for diagnosing LVA. Although a higher concordance rate of HRT2-MRI was found compared with previous studies utilizing earlier MRI technology, HRCT still detected a larger number of patients with clinically significant hearing loss compared with MRI. Given the high concordance rate and efficacy of both modalities in diagnosing LVA, the ultimate decision of which modality to choose may depend on other patient-specific and clinical factors.

Neuroimaging abnormalities in patients with Cowden syndrome: Retrospective single-center study

Background We retrospectively reviewed the neuroimaging findings of patients with Cowden syndrome and determined their frequency in a single cohort. Methods Electronic medical records were queried from January 1999 to January 2017 to identify patients who fit the clinical criteria for diagnosis of Cowden syndrome with or without a documented PTEN mutation. Patients with brain MRI examinations were then identified. Results We retrospectively identified 44 patients with Cowden syndrome, 22 of whom had neuroimaging for review. Eleven (50%) had Lhermitte-Duclos disease, 4 (18.1%) had meningiomas, 13 (59.1%) had at least one developmental venous anomaly, 3 had cavernous malformations, 2 had evidence of dural arteriovenous fistula, 7 had increased white matter signal abnormalities relative to age (31.8%), 4 had prominent perivascular spaces, cerebellar tonsillar ectopia was present in 7 of 21 (33.3%), and 1 had cortical malformation. Conclusions It is important to recognize that in addition to Lhermitte-Duclos disease, other intracranial findings such as multiple venous anomalies, meningiomas, greater than expected white matter signal abnormality, prominent perivascular spaces, and cortical malformations may warrant a thorough evaluation for Cowden syndrome in the appropriate clinical setting. We further recommend that this broader spectrum of intracranial abnormalities be considered for addition to the Cowden syndrome diagnostic criteria at the time of next revision.

Hypoglossal Canal Lesions: Distinctive Imaging Features and Simple Diagnostic Algorithm

OBJECTIVE The objective of this study is to compare the prevalence of hypoglossal canal lesions and identify differentiating imaging features. MATERIALS AND METHODS A 15-year retrospective review of lesions of the hypoglossal nerve and hypoglossal canal, excluding those in patients with metastasis or prior head and neck cancer and those treated with radiation or surgery, was performed. Clinical findings and lesion imaging features were documented. The contrast-enhanced T1-weighted nonenhancing cystic component of hypoglossal schwannomas was compared with size-matched pathologically proven vestibular schwannomas. RESULTS Our review identified 40 lesions encroaching on the hypoglossal canal, located within the hypoglossal canal, or found in both locations: 16 hypoglossal schwannomas, 15 juxtaarticular cysts, and nine purely cystic hypoglossal canal lesions. Hypoglossal schwannomas, which were intradural when involving the premedullary cistern, most commonly enhanced heterogeneously, with a thick peripheral enhancing component, a central enhancing component, or both enhancing components. Juxtaarticular cysts encroaching on the hypoglossal canal were extradural, were contiguous with a craniocervical junction synovial joint, and showed thin rim enhancement. Hypoglossal canal nonenhancing cystic lesions were confined to the hypoglossal canal, had signal intensity equivalent to CSF, and lacked any contrast enhancement. CONCLUSION Although hypoglossal schwannomas, juxtaarticular cysts, and hypoglossal canal nonenhancing cystic lesions may all encroach on or lie within the hypoglossal canal, purely cystic lesions are unlikely to be schwannomas. A diagnostic algorithm applying key imaging and clinical findings allows differentiation of these lesions, which have vastly different treatment regimens.

Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings.

Objective: The radiologic appearance of arachnoid granulations (AGs) in typical locations is well established and they are rarely mistaken for other pathologies. However, when large and seen in atypical locations, such as along the posterior petrous bone, AGs can be a source of diagnostic and therapeutic confusion. We present two cases of giant posterior temporal bone AGs and review their clinical presentation, potential complications, and an imaging-based differential diagnosis. Patients: Two patients with surgically or pathologically proven giant symptomatic AGs in the posterior petrous bone. Main Outcome Measure: Clinical presentation, radiological features, surgical findings, and potential complications of giant AGs. Results: In two middle-aged women (37 and 55 years), computed tomography (CT) demonstrated solitary large lytic lesions in the posterior right petrous temporal bone. These were similar in appearance to cerebrospinal fluid (CSF) on magnetic resonance imaging (MRI), though they exhibited some minor deviations such as thin internal septations, mild peripheral enhancement, and heterogeneous signal on fluid-attenuated inversion recovery (FLAIR). The MRI appearance effectively distinguished the giant AGs from other lesions that can occur in this area such as endolymphatic sac tumor (ELST). Surgery was successfully performed to prevent complications from a CSF leak. Conclusion: The posterior temporal bone is an atypical location for AGs and can lead to diagnostic confusion, particularly when they are large. Familiarity with the characteristic imaging appearance of giant AGs in this location can help avoid misinterpretation as a more aggressive pathology and help recognize patients who are at risk for a CSF leak.