Incomplete Cord Syndromes: Clinical and Imaging Review.

The ability to localize the three spinal tracts (corticospinal tract, spinothalamic tract, and dorsal [posterior] columns) involved in incomplete spinal cord syndromes at cross-sectional imaging and knowledge of the classic clinical manifestations of the various syndromes enable optimized imaging evaluation and provide clinicians with information that aids in diagnosis and treatment. The requisite knowledge for localizing these tracts is outlined. The authors review the spinal cord anatomy, blood supply, and course of these tracts and describe the various associated syndromes: specifically, dorsal cord, ventral cord, central cord, Brown-Séquard, conus medullaris, and cauda equina syndromes. In addition, they describe the anatomic basis for the clinical manifestation of each syndrome and the relevant imaging features of the classic causes of these entities. Knowledge of the anatomy and clinical findings of the spinal cord is essential for examining and treating patients with cord abnormalities. ©RSNA, 2018.

Multimodality Imaging Spectrum of the Extranodal Lymphomas in the Head and Neck-A Pictorial Review.

Lymphoma is the second most common malignant neoplasm of the head and neck region, involving the nodal and/or extranodal sites or both in a variable fashion. Lymphoma may mimic a variety of tumors in this region depending on the subsite involved. The usual presentation of lymphomatous disease is presence of multiple enlarged, often conglomerate, lymph nodes without significant necrosis. Extranodal lymphomas demonstrate more complex radiologic features, but careful evaluation can identify distinct imaging patterns to suggest extranodal lymphomatous disease from other more common lesions. Knowledge of these imaging features can help raise suspicion for lymphoma as a differential consideration. This can be of critical importance since further work-up and management can be vastly different between lymphomatous disease and other disease entities. The authors present a pictorial review of the spectrum of imaging findings in extranodal head and neck lymphomas.

Imaging of Intracranial and Orbital Complications of Sinusitis and Atypical Sinus Infection: What the Radiologist Needs to Know.

Sinusitis is a common disease. Complications, however, are less common and can be life threatening. Major complications occur from extension of disease into the orbit and intracranial compartment and often require emergent treatment with intravenous (IV) antibiotics or operative intervention. Immunocompromised patients with acute sinusitis are susceptible to atypical infections, such as invasive fungal sinusitis, which is a surgical emergency. Therefore, it is important to accurately and promptly identify potentional complications of acute sinusitis to ensure appropriate treatment and minimize negative outcomes. This article reviews the imaging features of a spectrum of complications associated with acute sinusitis and atypical infections.

The Many Faces of Granulomatosis With Polyangiitis: A Review of the Head and Neck Imaging Manifestations.

OBJECTIVE: Wegener granulomatosis has recently been renamed as granulomatosis with polyangiitis (GPA). In this review, we examine the clinical criteria and pathologic and pathophysiologic mechanisms of GPA, with an emphasis on findings encountered in the realm of head and neck imaging. Particular attention is paid to generating an appropriate differential diagnosis, because many of the imaging features of GPA overlap with those of other diseases, most notably lymphoma and sarcoidosis. Recent therapeutic advancements have underscored the importance of the radiologist in suggesting the diagnosis early, resulting in earlier treatment and decreased patient morbidity. This is particularly true for the head and neck manifestations of GPA; although they are less common, they often herald a refractory disease course that requires aggressive immunosuppressive therapy. Knowledge of common and uncommon imaging findings enables the radiologist to diagnose GPA early enough to start treatment promptly and reduce patient morbidity. CONCLUSION: Although there are no reliable pathognomonic imaging features for GPA, the present article attempts to identify patterns of disease that are suggestive of the disease. The diagnosis ultimately relies on a constellation of radiographic findings, laboratory values, and accurate clinical history.

Imaging of the skull base: anatomy and pathology.

The skull base is a critical landmark, separating intracranial from extracranial structures. This intricate anatomic structure has several foramina and crossing structures, which can be a challenge for novices. Comprehensive anatomic knowledge is critical for narrowing the differential diagnosis of lesions that may affect the skull base. These lesions can be divided into major categories to help in a systematic approach for skull base pathology evaluation.

Imaging of ectopic thyroid tissue and thyroglossal duct cysts.

When a child or young adult presents with a mass in the anterior portion of the neck, diagnostic considerations include a thyroglossal duct cyst and ectopic thyroid tissue. These entities are often suspected clinically, and imaging provides an opportunity to evaluate the extent, confirm the diagnosis, and evaluate for complications. Imaging characteristics of a thyroglossal duct cyst as a simple cyst and of ectopic thyroid tissue as a hyperattenuating soft-tissue mass can help identify these lesions at computed tomography (CT); however, intrinsic magnetic resonance, CT, and ultrasonographic imaging characteristics alone cannot be used to confirm the diagnosis. Rather, knowledge of the typical course of the thyroid primordium during embryologic development is essential to understand the variant locations along this path where thyroid tissue can be found. The migration of thyroid primordium begins at the foramen cecum at the base of the tongue and then loops around the hyoid bone anteriorly and inferiorly and descends anteriorly to the thyrohyoid membrane into the orthotopic location in the infrahyoid portion of the neck. Thyroid ectopia is categorized into one of four typical locations with respect to this embryologic course: (a) the base of the tongue, (b) adjacent to the hyoid bone, (c) the midline infrahyoid portion of the neck, and, rarely, (d) the lateral part of the neck. The differential diagnosis includes metastatic thyroid carcinoma, branchial cleft cyst, lymphatic malformation, abscess, saccular cyst, epidermoid cyst, and squamous cell carcinoma. The relationship of a mass to landmarks such as the foramen cecum, hyoid bone, strap muscles, thyrohyoid membrane, and thyroid cartilage can help differentiate a thyroglossal duct cyst and ectopic thyroid tissue from other anterior neck masses when the embryologic thyroid course is considered.

An algorithm for the management of posttraumatic cervical spondyloptosis.

Posttraumatic cervical spondyloptosis is the most severe form of fracture dislocation. Since its occurrence is uncommon, there is no consensus on its surgical management. Detailed description of five patients who were successfully managed through one approach (posterior or anterior) is presented, a review of the current literature is reported, and biomechanics is provided. An algorithm for the treatment of cervical spondyloptosis is then proposed.

Anatomy and embryology of the thyroid and parathyroid glands.

The thyroid and parathyroid glands are cervical endocrine glands responsible for metabolism-related functions. Radiologists are frequently asked to evaluate pathology related to the thyroid and parathyroid glands before planned surgical intervention. Knowledge of embryology and anatomy is fundamental in this region because rather complex underlying embryology produces substantial anatomic variation both in the thyroid bed and elsewhere in the neck and mediastinum.

Incidental findings on cone beam computed tomography images.

Background. Cone beam computed tomography (CBCT) has gained widespread acceptance in dentistry for a variety of applications. Most dentists who are not radiologists/trained in radiology are generally not familiar with interpretation of anatomical structures and/or pathosis outside their area of primary interest, as often this was not within the scope of their training. Objectives. To assess that the number of incidental findings on a CBCT scan is high both within and outside of the primary area of interest, thereby emphasizing the importance of interpretation of all areas visualized on the scan. Materials and Methods. An oral and maxillofacial radiologist reviewed 1000 CBCT scans (382 males and 618 females) for findings both in- and outside the area of interest. Results. Of the 1000 subjects that were reviewed, 943 scans showed findings in the primary regions of interest and/or outside the regions of interest, and 76 different conditions were visualized in these scans both in and outside the areas of interest. Conclusion. From the wide scope of findings noted on these scans, it can be concluded that it is essential that a person trained in advanced interpretation techniques in radiology interprets cone beam computed tomography scans.

A case of solitary Blastomyces dermatitidis meningitis.

We present a case of a 35 year-old male with Blastomyces dermatitidis meningitis as the primary presentation of blastomycosis infection, without evidence of involvement outside the CNS at time of discharge. We focus on the magnetic resonance imaging findings, with histopathologic correlation.

Duplication of the internal carotid artery presenting with severe atherosclerotic stenosis.

Duplication of the extracranial internal carotid artery is a rare anatomic variant. We present the first patient with unilateral duplication of the cervical internal carotid artery with severe stenosis. Stent-assisted percutaneous transluminal angioplasty was successfully performed to restore blood flow. We discuss the angiographic findings and endovascular treatment.

Previous statin use is not associated with an increased prevalence or degree of gradient-echo lesions in patients with acute ischemic stroke or transient ischemic attack.

BACKGROUND AND PURPOSE: Microhemorrhages on gradient-echo T2*-weighted MRI sequences are often found in patients with cerebrovascular disease and are related to intracerebral hemorrhage. Because statin therapy is associated with increased risk of intracerebral hemorrhage, we investigated whether statin use was also associated with microhemorrhages in patients with acute ischemic stroke or transient ischemic attack. METHODS: We performed a retrospective analysis on prospectively collected data from a stroke registry containing patients with acute ischemic stroke or transient ischemic attack. The primary and secondary outcome variables were the prevalence and degree of microhemorrhages as detected on gradient-echo MRI sequences and categorized as mild (1-2), moderate (3-10), or severe (>10). The location of the microhemorrhages was noted and rated by 2 neuroradiologists. Previous use of statins and other covariates were assessed as potential predictors. RESULTS: Three hundred forty-nine patients were admitted from June 2008 to July 2009, and 300 of which were analyzed. Microhemorrhages were detected in 70 subjects (23%); 35 had only lobar lesions, 16 had only deep lesions, and 19 had both lobar and deep lesions. On univariate and multivariate analysis, statin therapy was not associated with the prevalence (OR, 0.73; 95% CI, 0.36-1.51; P=0.40) or degree of microhemorrhages modeled for lesser severity (OR, 2.31; 95% CI, 0.61-8.75; P=0.22). CONCLUSIONS: Previous statin therapy was not associated with the prevalence or degree of microhemorrhages in patients with acute ischemic stroke or transient ischemic attack. The association between statins and intracerebral hemorrhage does not appear to be mediated through microhemorrhages.

Orbital roof encephalocele mimicking a destructive neoplasm.

The purpose of this case report is to report an orbital roof encephalocele mimicking a destructive orbital neoplasm. Orbital roof encephalocele is uncommon but can mimic neoplasm. One potential mechanism for the orbital roof destruction is a post-traumatic "growing orbital roof fracture." The growing fracture has been reported mostly in children but can occur in adults. Alternative potential etiologies for the encephalocele are discussed, including Gorham syndrome. Orbital roof encephalocele is uncommon in adults, and the findings can superficially resemble an orbital neoplasm. Radiographic and clinical features that might suggest the correct diagnosis include a prior history of trauma, overlying frontal lobe encephalomalacia without significant mass effect or edema, and an orbital roof defect. The "growing fracture" mechanism may be a potential explanation for the orbital roof destruction in some cases.

Anomalous origins of the calcarine and parieto-occipital arteries.

Understanding cerebrovascular anatomy and its variations is of utmost importance in treating vascular malformations. The two patients presented here demonstrate yet to be reported anomalous origins of the cortical branches of the posterior cerebral artery. In one patient, fetal calcarine arteries were identified arising from the internal carotid arteries bilaterally with no calcarine branches arising from the posterior circulation and the basilar artery giving rise to terminal parieto-occipital arteries. Additionally, with vertebral artery injections, we found the dominant arterial supply to the right parieto-occipital artery arose from the right internal carotid artery and right posterior communicating artery and the dominant arterial supply to the left parieto-occipital artery arose from the right vertebral artery. A second patient demonstrated anomalous origins of the calcarine and parietal occipital branches from the supraclinoid left internal carotid artery. Understanding this complex cerebrovascular anatomy is important in the endovascular treatment of cerebrovascular aneurysms and malformations.

Imaging for neuro-ophthalmic and orbital disease - a review.

A literature review was performed by content experts in neuro-ophthalmology and neuroradiology using a systematic English-language Medline search (1994-2008) limited to articles with relevance to neuro-ophthalmic and orbital imaging. The information covered in this review includes: (i) the basic mechanics, indications and contraindications for cranial and orbital computed tomography and magnetic resonance (MR) imaging; (ii) the utility and indications for intravenous contrast, (iii) the use of specific MR sequences; (iv) the techniques and ophthalmic indications for computed tomography/MR angiography and venography; and (v) the techniques and indications for functional MR imaging, positron emission tomography scanning and single photon emission computed tomography. Throughout the review accurate and timely communication with the neuroradiologist regarding the clinical findings and suspected location of lesions is emphasized so as to optimize the ordering and interpretation of imaging studies for the ophthalmologist.

Pathologic conditions of the lower cranial nerves IX, X, XI, and XII.

The glossopharyngeal, vagus, spinal accessory, and hypoglossal cranial nerves can be affected by an acute or chronic process that has an impact on the way the patient presents clinically. Knowledge of nerve pathways and relations to surrounding structures is fundamental when evaluating patients who have lower cranial nerve symptoms. A systematic "segment-based" approach helps to narrow the differential diagnosis Pathologic conditions that cause lower cranial nerve symptoms are presented.

Horner's syndrome: clinical and radiographic evaluation.

Horner's syndrome (HS) occurs when there is interruption of the oculosympathetic pathway (OSP). This article reviews the anatomy of the OSP and clinical findings associated with lesions located at various positions along this pathway. The imaging findings of lesions associated with HS at various levels of the OSP, classified as preganglionic HS (first- and second-order neuron HS) or postganglionic HS (third-order neuron HS), are demonstrated.

Denervation atrophy of motor cranial nerves.

Muscles undergoing denervation demonstrate a variety of imaging appearances in the various stages. It is incumbent on the radiologist to be aware of these changes so as not to interpret these muscles as harboring a tumor or being involved by an inflammatory process. Knowledge of cranial nerve anatomy and the muscles they innervate enables identification of denervation patterns that could implicate more than one nerve and directs the search for the causative lesion.

Imaging the craniocervical junction.

INTRODUCTION: The craniovertebral junction (CVJ) comprises the occiput, atlas, and axis. Radiographic evaluation of this region involves knowledge of only a few anatomical landmarks, as well as basic normal measurements and relationships to perform CVJ craniometry. Occipital bone anomalies and atlanto-occipital non-segmentation typically produce basilar invagination. Atlas anomalies predominantly involve the posterior arch, while the os odontoideum accounts for the majority of axis anomalies. RESULTS AND DISCUSSION: A number of syndromes are associated with CVJ pathology, the most notable being Klippel-Feil and Down syndromes, achondroplasia, the mucopolysaccharidoses, and osteogenesis imperfecta. Skull-base softening associated with some of these syndromes results in acquired basilar invagination or basilar impression. In this article, we present a detailed review of essential anatomy and craniometry needed for radiographic assessment of the CVJ and illustrate various congenital anomalies of the occiput, atlas, and axis. The common syndromes affecting this region are also discussed and illustrated.