Imaging of Inflammatory Disorders of Salivary Glands.

Sialadenitis is among the most common conditions that affect the salivary glands. Inflammation of the salivary glands occurs as the end result of a variety of pathologic conditions, including infectious, autoimmune, and idiopathic causes. Clinically, inflammation of the salivary gland causes pain and localized swelling. The presentation may be acute or chronic, and can be recurrent. Because there is significant overlap of underlying disease mechanisms and clinical presentations, radiologic evaluation often plays a significant role in evaluation. This article is a brief review of sialadenitis, including disease mechanisms, causes, and the practical imaging of the salivary glands.

Late-Onset Cerebral Toxoplasmosis After Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND Toxoplasmosis is an uncommon but potentially fatal complication following allogeneic hematopoietic stem cell transplantation (HCT). Post-transplant toxoplasmosis is often a reactivation of prior infection and typically occurs within the first 6 months of transplant. Herein, we report that cerebral toxoplasmosis may occur 22 months after allogeneic hematopoietic stem cell transplantation. CASE REPORT We describe a case of cerebral toxoplasmosis that occurred 22 months after an allogeneic HCT while the patient was on aerosolized pentamidine for Pneumocystis jiroveci pneumonia (PCP) prophylaxis. The disease was only diagnosed after brain biopsy because of atypical MRI appearance of the cerebral lesion and negative Toxoplasma gondii IgG antibody test result in the cerebrospinal fluid (CSF). The patient received pyrimethamine and sulfadiazine treatment, with dramatic improvement after several months. The patient is alive 2 years after infection diagnosis, with no evidence of disease and is off Toxoplasma prophylaxis. CONCLUSIONS Cerebral toxoplasmosis can occur late after allogeneic HCT while patients are on immunosuppression therapy, with atypical features on imaging studies and negative Toxoplasma gondii IgG antibody test result in the CSF. Pre-transplant serologic screening for T. gondii antibodies in allogeneic transplant candidates is warranted. Brain biopsy can be a helpful diagnostic tool for cerebral lesions.

Absent Vascular Signal on Time-of-Flight Magnetic Resonance Angiography Due to Recent Ferumoxytol Infusion.

Time-of-flight magnetic resonance angiography is used for craniocervical arterial evaluation. Absent flow-related signal may be the result of slow flow, complex flow, or focal susceptibility effects. We report a case with complete absence of flow-related signal in the intracranial and cervical vessels due to ferumoxytol infusion given 5 days before magnetic resonance angiography. Ferumoxytol is a newly approved parenteral therapy for iron-deficiency anemia in patients with renal failure and awareness of this drug-magnetic resonance imaging interaction is needed.

Practical imaging of the parotid gland.

The parotid gland may be affected by numerous pathologies, and physicians from many different medical and surgical specialties request parotid imaging. Mastering the typical imaging features of various types of parotid pathology is facilitated by understanding how various diseases produce their characteristic imaging findings. In this review article, we present succinct overviews of the normal anatomy and the common pathologies of the parotid gland and recommend a practical approach to differential diagnosis that can be easily implemented in day-to-day radiology practice.

Imaging of the temporomandibular joint: An update.

Imaging of the temporomandibular joint (TMJ) is continuously evolving with advancement of imaging technologies. Many different imaging modalities are currently used to evaluate the TMJ. Magnetic resonance imaging is commonly used for evaluation of the TMJ due to its superior contrast resolution and its ability to acquire dynamic imaging for demonstration of the functionality of the joint. Computed tomography and ultrasound imaging have specific indication in imaging of the TMJ. This article focuses on state of the art imaging of the temporomandibular joint. Relevant normal anatomy and biomechanics of movement of the TMJ are discussed for better understanding of many TMJ pathologies. Imaging of internal derangements is discussed in detail. Different arthropathies and common tumors are also discussed in this article.

Observer reliability of arteriovenous malformations grading scales using current imaging modalities.

OBJECT: The aim of this study was to examine observer reliability of frequently used arteriovenous malformation (AVM) grading scales, including the 5-tier Spetzler-Martin scale, the 3-tier Spetzler-Ponce scale, and the Pollock-Flickinger radiosurgery-based scale, using current imaging modalities in a setting closely resembling routine clinical practice. METHODS: Five experienced raters, including 1 vascular neurosurgeon, 2 neuroradiologists, and 2 senior neurosurgical residents independently reviewed 15 MRI studies, 15 CT angiograms, and 15 digital subtraction angiograms obtained at the time of initial diagnosis. Assessments of 5 scans of each imaging modality were repeated for measurement of intrarater reliability. Three months after the initial assessment, raters reassessed those scans where there was disagreement. In this second assessment, raters were asked to justify their rating with comments and illustrations. Generalized kappa (κ) analysis for multiple raters, Kendall's coefficient of concordance (W), and interclass correlation coefficient (ICC) were applied to determine interrater reliability. For intrarater reliability analysis, Cohen's kappa (κ), Kendall's correlation coefficient (tau-b), and ICC were used to assess repeat measurement agreement for each rater. RESULTS: Interrater reliability for the overall 5-tier Spetzler-Martin scale was fair to good (ICC = 0.69) to extremely strong (Kendall's W = 0.73) on initial assessment and improved on reassessment. Assessment of CT angiograms resulted in the highest agreement, followed by MRI and digital subtraction angiography. Agreement for the overall 3-tier Spetzler-Ponce grade was fair to good (ICC = 0.68) to strong (Kendall's W = 0.70) on initial assessment, improved on reassessment, and was comparable to agreement for the 5-tier Spetzler-Martin scale. Agreement for the overall Pollock-Flickinger radiosurgery-based grade was excellent (ICC = 0.89) to extremely strong (Kendall's W = 0.81). Intrarater reliability for the overall 5-tier Spetzler-Martin grade was excellent (ICC > 0.75) in 3 of the 5 raters and fair to good (ICC > 0.40) in the other 2 raters. CONCLUSION: The 5-tier Spetzler-Martin scale, the 3-tier Spetzler-Ponce scale, and the Pollock-Flickinger radiosurgery-based scale all showed a high level of agreement. The improved reliability on reassessment was explained by a training effect from the initial assessment and the requirement to defend the rating, which outlines a potential downside for grades determined as part of routine clinical practice to be used for scientific purposes.

Computational fluid dynamic analysis of the posterior airway space after maxillomandibular advancement for obstructive sleep apnea syndrome.

PURPOSE: This study evaluated the soft tissue change of the upper airway after maxillomandibular advancement (MMA) using computational fluid dynamics. MATERIALS AND METHODS: Eight patients with obstructive sleep apnea syndrome who required MMA were recruited into this study. All participants underwent pre- and postoperative computed tomography and then MMA by a single oral and maxillofacial surgeon. Upper airway computed tomographic datasets for these 8 patients were created with high-fidelity 3-dimensional numerical models for computational fluid dynamics. The 3-dimensional models were simulated and analyzed to study how changes in airway anatomy affect the pressure effort required for normal breathing. Airway dimensions, skeletal changes, apnea-hypopnea index, and pressure effort of pre- and postoperative 3-dimensional models were compared and correlations were interpreted. RESULTS: After MMA, laminar and turbulent air flows were significantly decreased at every level of the airway. The cross-sectional areas at the soft palate and tongue base were significantly increased. CONCLUSIONS: This study showed that MMA increased airway dimensions by increasing the distance from the occipital base to the pogonion. An increase of this distance showed a significant correlation with an improvement in the apnea-hypopnea index and a decreased pressure effort of the upper airway. Decreasing the pressure effort will decrease the breathing workload. This improves the condition of obstructive sleep apnea syndrome.

Timing and mechanism of ischemic stroke due to extracranial blunt traumatic cerebrovascular injury.

OBJECT: Extracranial cerebrovascular injury is believed to be an important cause of neurological injury in patients who have suffered blunt trauma. The authors sought to determine the timing and mechanisms of ischemic stroke in patients who suffered traumatic cerebrovascular injury (TCVI). METHODS: This is a prospective study of all patients with TCVI who were admitted to a Level I trauma center during a 28-month period. All patients who suffered blunt trauma and had risk factors for TCVI underwent screening CT angiography (CTA) of the head and neck on admission. All patients with either an ischemic stroke or CTA suggesting TCVI underwent confirmatory digital subtraction angiography (DSA). Patients with DSA-confirmed TCVI were treated with 325 mg aspirin daily; all patients were observed during their hospitalization for the occurrence of new ischemic stroke. In addition, a subset of patients with TCVI underwent transcranial Doppler ultrasonography monitoring for microembolic signals. RESULTS: A total of 112 patients had CTA findings suggestive of TCVI; 68 cases were confirmed by DSA. Overall, 7 patients had an ischemic stroke in the territory of the affected artery prior to or during admission. Four of the patients had their event prior to diagnosis with CTA and 2 occurred prior to DSA. In 1 patient the ischemic stroke was found to be due to an extracranial atherosclerotic carotid plaque, and this patient was excluded from further analysis. All patients with ischemic stroke had brain CT findings consistent with an embolic mechanism. Two (8.7%) of 23 monitored patients with TCVI had microembolic signals on transcranial Doppler ultrasonography. CONCLUSIONS: Most ischemic strokes due to TCVI are embolic in nature and occur prior to screening CTA and initiation of treatment with aspirin.

Prognostic significance of thyroid or cricoid cartilage invasion in laryngeal or hypopharyngeal cancer treated with organ preserving strategies.

BACKGROUND: The utility of definitive radiotherapy (RT) for locoregionally advanced squamous cell carcinoma (SCC) of the larynx or hypopharynx in the setting of thyroid or cricoid cartilage invasion (TCCI) is controversial. A retrospective review of our experience was performed. METHODS: Our institutional database of patients with SCC of the head and neck treated with radiotherapy (90% received concurrent systemic therapy) between 1995 and 2009 was queried. We identified 87 patients with T3-4 laryngeal or T4 hypopharyngeal cancer for whom initial head and neck imaging was available for review. Imaging of all patients was reviewed by a single radiologist specializing in neuroradiology. The presence and extent of TCCI was determined and used for stratification. RESULTS: Median follow-up was 34 months. TCCI was found in 25 (29%) patients, eight limited to the inner cortex and another 17 involving both cortices. Local control (LC) was not significantly affected by TCCI limited to the inner cortex. However, TCCI involving both cortices was correlated with diminished LC at 2 years compared to the group of patients with no or minor invasion (55% vs. 81%, p=0.045). However, TCCI involving both cortices was not associated with significantly reduced rates of survival with a functional larynx, or overall survival (OS). CONCLUSIONS: Our results suggest that the rate of LC of T3-4 laryngeal or T4 hypopharyngeal SCC treated with definitive RT is not affected by TCCI of the inner cortex. Although decreased LC was significantly associated with TCCI involving both cortices, this factor did not appear to result in reduced rates of survival with a functional larynx or OS. Therefore, organ preservation may remain an option in these patients.

Radiopaque jaw lesions: an approach to the differential diagnosis.

Radiopaque jaw lesions are frequently encountered at radiography and computed tomography, but they are usually underevaluated or underdescribed in radiology reports. A systematic approach to the evaluation of radiopaque jaw lesions is necessary to diagnose the lesion or at least provide a meaningful differential diagnosis. To evaluate a radiopaque jaw lesion, the first, most important step is to categorize the lesion according to its attenuation, its relationship to the teeth, and its location with respect to the tooth. These basic observations are essential to the evaluation of any type of jaw lesion. Once these observations have been made, it is easy to create a proper differential diagnosis. The presence of important characteristics, such as margination, a perilesional halo, bone expansion, and growth pattern, as well as whether the lesion is sclerotic, has ground-glass attenuation, or is mixed lytic and sclerotic, further narrows the differential diagnosis. It is important to note that some radiopaque jaw lesions may be entirely lucent early in their evolution. Awareness of the demographic distribution of these lesions and their associated clinical features, as well as the radiologic approach, is important to explore the "terra incognita" of radiopaque jaw lesions.

Radiation necrosis in the brain: imaging features and differentiation from tumor recurrence.

Radiation necrosis in the brain commonly occurs in three distinct clinical scenarios, namely, radiation therapy for head and neck malignancy or intracranial extraaxial tumor, stereotactic radiation therapy (including radiosurgery) for brain metastasis, and radiation therapy for primary brain tumors. Knowledge of the radiation treatment plan, amount of brain tissue included in the radiation port, type of radiation, location of the primary malignancy, and amount of time elapsed since radiation therapy is extremely important in determining whether the imaging abnormality represents radiation necrosis or recurrent tumor. Conventional magnetic resonance (MR) imaging findings of these two entities overlap considerably, and even at histopathologic analysis, tumor mixed with radiation necrosis is a common finding. Advanced imaging modalities such as diffusion tensor imaging and perfusion MR imaging (with calculation of certain specific parameters such as apparent diffusion coefficient ratios, relative peak height, and percentage of signal recovery), MR spectroscopy, and positron emission tomography can be useful in differentiating between recurrent tumor and radiation necrosis. In everyday practice, the visual assessment of diffusion-weighted and perfusion images may also be helpful by favoring one diagnosis over the other, with restricted diffusion and an elevated relative cerebral blood volume being seen much more frequently in recurrent tumor than in radiation necrosis.

Primary central nervous system angiosarcoma: two case reports.

INTRODUCTION: Primary angiosarcoma of the brain is extremely rare; only 15 cases have been reported in adults over the last 25 years. CASE PRESENTATIONS: We describe two cases of primary angiosarcoma of the brain that are well characterized by imaging, histopathology, and immunohistochemistry. Case 1: our first patient was a 35-year-old woman who developed exophthalmos. Subtotal resection of a left extra-axial retro-orbital mass was performed. Case 2: our second patient was a 47-year-old man who presented to our facility with acute visual loss, word-finding difficulty and subtle memory loss. A heterogeneously-enhancing left sphenoid wing mass was removed. We also review the literature aiming at developing a rational approach to diagnosis and treatment, given the rarity of this entity. CONCLUSIONS: Gross total resection is the standard of care for primary angiosarcoma of the brain. Adjuvant radiation and chemotherapy are playing increasingly recognized roles in the therapy of these rare tumors.

An aberrant cerebellar artery originating from the internal carotid artery.

The aberrant origin of the cerebellar arteries from anterior cerebral circulation is a quite rare vascular variation. Herein, we report a 52-year-old white female with angiographically occult subarachnoid hemorrhage. Left superior and anterior inferior cerebellar arteries were not detected. An aberrant cerebellar artery was noted to arise from the left cavernous internal carotid artery and terminated in the distribution of the ipsilateral superior and anterior inferior cerebellar arteries. This variant artery might likely have resulted from an abnormal regression of fetal anterior-to-posterior circulation connections, and may represent a fetal-type cerebellar artery. A review of the anatomy and clinical significance of the variant is presented.

How can we diagnose and treat osteomyelitis of the jaws as early as possible?

Osteomyelitis of the jaws is an uncommon infection of the maxillofacial area. The disease is often difficult to diagnose, and thus delays in treatment are common, increasing its morbidity. The clinical, radiographic, and laboratory findings of the disease; its forms; and treatment modalities are reviewed. Suggestions for contemporary diagnosis and surgical treatment of acute and chronic suppurative osteomyelitis are discussed.

The oblique occipital sinus: a review of anatomy and imaging characteristics.

Variations of the dural venous sinuses may result in inaccurate imaging interpretation or complications during surgical approaches. One variation of the dural venous sinuses reported infrequently in the literature is the oblique occipital sinus. The present paper reviews this anatomy and offers illustrations of the cadaveric and imaging findings seen with this venous variation.

Imaging of petrous apex lesions: self-assessment module.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the role of imaging in the evaluation of petrous apex lesions.

Toluene optic neurotoxicity: magnetic resonance imaging and pathologic features.

Toluene, a colorless liquid found in glues, paints, and industrial products, is lipid soluble and rapidly absorbed by the lipid-rich central nervous system. Prolonged exposure through occupation or purposeful inhalation may lead to neurologic abnormalities. Two men presented with multifocal central nervous system defects and bilateral optic neuropathy of unclear etiology. After numerous diagnostic tests, including brain magnetic resonance imaging, lumbar puncture, hematologic studies, and in one patient a brain biopsy, chronic inhalation of toluene was found to be the cause. Timely diagnosis is important because patients may experience improvement in neurologic and ocular manifestations with cessation of exposure, whereas continued inhalant abuse or exposure can result in permanent loss of neurologic function.

Persistent fetal intracranial arteries: a comprehensive review of anatomical and clinical significance.

As fetal intracranial vessels may persist into adulthood, knowledge of their anatomy and potential clinical and surgical complications should be borne in mind by the surgeon. A comprehensive review of these vessels, however, is not easily identified in the literature. Therefore, the present analysis was undertaken so that such information is available to the clinician and morphologist.