Neuroimaging of Headache: Indications and Controversies.

Headache is a common presenting symptom in the ambulatory setting that often prompts imaging. The increased use and associated health care money spent in the setting of headache have raised questions about the cost-effectiveness of neuroimaging in this setting. Neuroimaging for headache in most cases is unlikely to reveal significant abnormality or impact patient management. In this article, reasons behind an observed increase in neuroimaging and its impact on health care expenditures are discussed. The typical imaging modalities available and various imaging guidelines for common clinical headache scenarios are presented, including recommendations from the American College of Radiology.

Chest CT Has Higher Yield for Infection than CT Sinus in Febrile Neutropenic Patients.

OBJECTIVE: Chest and sinus CT imaging among cancer patients undergoing chemotherapy and bone marrow transplant in the setting of neutropenic fever is not uncommon, yet the utility of routine imaging surveillance remains unclear. We aim to compare the rates of acute infection detected on CT chest and CT sinus exams performed in this clinical setting. METHODS: Reports of 1059 consecutive CT chest and sinus examinations for the clinical indication of neutropenic fever on 262 patients performed between January through June 2017 were retrospectively reviewed. Infection as reported was characterized as acute or worsening, improving, stable, indeterminate or negative. Results were tabulated and Pearson's chi-square test was used for comparison analysis. RESULTS: Absence of infection on CT sinus was significantly higher than CT chest (86.1% vs. 58.5%; P<0.001). Conversely, CT chest had significantly higher incidence of acute or worsening infection than CT sinus (28.7% vs. 11.6%; P<0.001). CT chest also showed significantly higher incidence of improving infection compared to CT sinus (6.2% vs. 1.1%; P<0.001). There was no significant difference between incidence of stable infection on CT chest and CT sinus (1.1% vs. 0.2%; P=0.059). Infection was indeterminate in 5.5% of CT chest vs. 1% on CT sinus (P<0.001). CONCLUSIONS: CT chest showed significantly higher diagnostic yield for acute infection than CT sinus, suggesting that sinusitis is less likely to be the source of fever than chest infections in febrile neutropenic patients. The majority of CT studies showed absence of infection, raising the question of the overall utility of routine surveillance CT imaging among this subset of patients.

Imaging of the Postoperative Skull Base and Cerebellopontine Angle.

For pathologic conditions affecting the skull base and cerebellopontine angle, imaging techniques have advanced to assess for residual disease, disease progression, and postoperative complications. Knowledge regarding various surgical approaches of skull base tumor resection, expected postoperative appearance, and common postsurgical complications guides radiologic interpretation. Complexity of skull base anatomy, small size of the relevant structures, lack of familiarity with surgical techniques, and postsurgical changes confound radiologic evaluation. This article discusses the imaging techniques, surgical approaches, expected postoperative changes, and complications after surgery of the skull base, with emphasis on the cerebellopontine angle, anterior cranial fossa, and central skull base regions.

Amyloidosis in the head and neck: CT findings with clinicopathological correlation.

PURPOSE: To characterize the CT imaging features of head and neck amyloidosis and correlate with extent of disease and clinical outcomes. MATERIALS AND METHODS: This retrospective study included 80 patients with head and neck amyloidosis who underwent soft tissue neck CT imaging between November 2003 and April 2018. The CT imaging features including lesion distribution, morphology (focal, diffuse/circumferential, or combined), presence and pattern of calcification, (punctate or diffuse), and thickness of airway lesion were evaluated and compared with the extent of amyloidosis (localized or systemic), and clinical course (stable, no recurrence, or progression requiring repeated surgical treatment). RESULTS: Localized disease (83.8%, 67/80) was most common with AL type (97.6%, 41/42) representing nearly all cases of head and neck amyloidosis. The larynx was the most frequently affected organ (60.0%, 48/80), specifically the glottis (43.8%, 35/80). Calcification was seen in 65.0% of cases (52/80). Non-airway or tongue lesions were significantly associated with systemic (92.3%, 12/13) as opposed to localized amyloidosis (4.5%, 3/67; P < 0.001). Repeated surgical treatment was significantly associated with laryngeal amyloidosis (35.3%, 12/34; P = 0.002) and multi-centric disease (33.3%, 10/30; P = 0.048). Airway wall thickness in patients who required repeated surgical treatment was significantly greater than in patients with stable or no recurrent disease (P = 0.016). CONCLUSION: Knowledge of the imaging features of head and neck amyloidosis can aid the diagnosis, disease monitoring, and prediction of patients requiring repeated surgical intervention.

Imaging features of vertebral artery fenestration.

PURPOSE: Vertebral artery fenestration (VAF) is a rare congenital vascular anomaly which has been associated with intracranial aneurysm. VAF can share some similar imaging features with vertebral artery dissection (VAD), which may confound diagnosis of the latter on CT and MR angiography. The purpose of this investigation is to assess the prevalence of VAF, evaluate its association with other vascular anomalies, and identify imaging features to help in distinguishing VAF and VAD. METHODS: Using keyword search on CTA and MRA head and neck imaging reports from 2010 to 2017, cases of VAF and VAD were retrospectively identified and imaging was reviewed. Imaging features including laterality; vertebral segment; length of affected segment; presence, number, and caliber of lumen(s); and presence of other vascular abnormalities were recorded for all cases and subsequently compared using Pearson's chi-squared test to assess for significant differences between the groups. Patient age, gender, and clinical presentations were also recorded. RESULTS: Of 64,888 CT and MR angiographic examinations performed, VAF was identified in 67 (0.1%) and VAD in 54 (0.1%) patients. Compared with VADs, VAFs were shorter in length (p < 0.001), wider in luminal diameter (p < 0.001), more likely to occur at the V4 segment (p < 0.01), more likely to have two distinct lumens rather than one (p < 0.01), and less likely to present post-trauma (p < 0.01). Coexisting intracranial aneurysms were identified in 9% of patients with VAF. CONCLUSION: VAFs, although rare, can be readily distinguished from VADs on angiographic imaging. Diagnosis of VAF should prompt review for intracranial aneurysm.

Use of Imaging During Emergency Department Visits for Low Back Pain.

OBJECTIVE. Back pain is one of the most common reasons for adult patients 18-65 years old to seek emergency care. Use of imaging for patients without so-called red flags (trauma, malignancy, or infection) may result in potentially unnecessary costs and radiation exposure. The aim of this study was to investigate the use of imaging for patients with emergency visits for low back pain. MATERIALS AND METHODS. Emergency department visits for patients with low back pain billed to insurance were identified by querying a national commercial claims and encounters database for patients 18-64 years old. Patients with concomitant encounter diagnoses suggestive of trauma or those with prior visits for back pain were excluded. Imaging modalities (radiography, CT, and MRI) were identified by Current Procedural Terminology codes. RESULTS. A total of 134,624 encounters met inclusion criteria. Imaging was obtained in 44,405 (33.7%) visits and decreased from 34.4% to 31.9% between 2011 and 2016 (odds ratio per year, 0.98 [95% CI, 0.98-0.99]; p < 0.001). During the study period, 30.9% of patients underwent radiography, 2.7% of patients underwent CT, and 0.8% of patients underwent MRI for evaluation of low back pain. The use of imaging varied significantly by geographic region (p < 0.001), with patients in the southern United States undergoing 10% more imaging than patients in the western United States. CONCLUSION. The use of imaging for the initial evaluation of patients with low back pain in the emergency department continues to occur at a high rate, in approximately one in three new emergency visits for low back pain in the United States.

Granulomatosis with Polyangiitis Manifesting as a Symptomatic Sellar Mass in a Young Woman.

A pituitary mass is a rare and poorly understood complication of granulomatosis with polyangiitis (GPA). Here we describe the case of a young woman with GPA who presented with signs and symptoms initially suggestive of meningitis but was ultimately found to have hypopituitarism and an enlarging sellar mass. She underwent transsphenoidal biopsy, which revealed an abundance of sterile inflammation and necrosis consistent with GPA-related inflammation. This case demonstrates a rare complication of GPA, i.e., a pituitary mass, initially mimicking meningitis. GPA-related pituitary involvement has an unknown pathogenesis and can have debilitating long-term consequences including chronic hypopituitarism and vision impairment, highlighting the need for further research.

Diagnostic Imaging Use for the Initial Evaluation of Low Back Pain by Primary Care Providers in the United States: 2011-2016.

OBJECTIVE: High-value care guidelines from multiple medical societies recommend against imaging for the initial evaluation of low back pain in the absence of red flag symptoms. We aimed to determine the current temporal and geographic landscape of imaging ordering patterns for this indication among US primary care providers. METHODS: Using a national commercial insurance claims database, we identified patients between 18 and 64 years old who presented to a primary care provider for an initial evaluation of low back pain between 2011 and 2016. Patients were identified via International Classification of Diseases codes, and the use of diagnostic imaging was identified by Current Procedural Terminology codes. Geographic regions were based on the location of patient residence. RESULTS: Overall, 627,118 encounters met inclusion criteria. Imaging acquisitions increased over time, from 14% of encounters in 2011 to 16% in 2016 (P < .01). Radiographs represented 96% of ordered imaging, CT 2%, and MRI 3%. The likelihood of having any imaging for low back pain varied significantly by US census region and by US state (P < .01). The greatest use of imaging was in the Midwest (13.9%) and the South (18.5%), and lowest in the Northeast and West (6.2% and 13.6%). DISCUSSION: Imaging utilization for the initial evaluation of low back pain by primary care providers has increased on a national level from 2011 to 2016, largely represented by radiographs. Significant regional variation also exists. Encouragingly, the use of advanced imaging has remained at a low level in the primary care setting (<1.0%).

CT in the Evaluation of Acute Injuries of the Anterior Eye Segment.

OBJECTIVE: Slit-lamp ophthalmologic examination and ocular B-scan sonography of the globe are frequently constrained by technical limitations in the setting of traumatic orbital injury. The main purpose of this study was to evaluate the diagnostic performance of CT in acute anterior segment ocular injuries as an adjunctive diagnostic modality. MATERIALS AND METHODS: We retrospectively identified 122 patients who presented to the emergency department from April 2011 through April 2016 with recent direct trauma to the anterior segment of the eye. Deidentified multiplanar thin-slice CT images were reviewed by two subspecialty board-certified neuroradiologists for the presence of anterior segment rupture and hyphema, as well as lens, ciliary body, and lacrimal gland injury. The CT findings were compared to slit-lamp, B-scan ultrasound, or operative data as the reference standard. RESULTS: The neuroradiologists' CT evaluation showed high sensitivity of 87.2% (95% CI, 74.3-95.2%) and specificity of 97.3% (95% CI, 90.7-99.7%) in diagnosing anterior globe rupture with high interrater agreement (κ = 0.876; 95% CI, 0.787-0.965). Detection of lens dislocation and anterior hyphema showed a sensitivity and specificity of 88.0% and 90.7% and 77.4% and 88.4%, respectively. A shallow anterior chamber was detectable with a sensitivity of 89.2% and specificity of 87.1%. This critically important sign predicted anterior globe rupture in 39 of 47 patients (odds ratio, 68.25; p < 0.0001). CONCLUSION: Subtle ocular findings are readily detectable at CT and can provide valuable information to the ophthalmologist concerning acute trauma to the ocular anterior segment.

Clinical Significance of Incidentally Detected Torus Tubarius Calcification.

OBJECTIVES: Calcification of the torus tubarius has been rarely reported in the literature. Histopathologic studies have previously described cases of Eustachian tube calcification and cite an association with increasing patient age. The purpose of this study was to examine the prevalence of torus tubarius calcification and potential clinical significance on an unrestricted patient population using thin-section computed tomography (CT), which has not been previously reported. METHODS: After the institutional review board approval, 1571 consecutive patients who underwent noncontrast head CT between January 2011 and July 2011 were retrospectively reviewed for torus tubarius calcification. Images were acquired at 1.25-mm slice thickness using a 64-detector row CT. Medical records were reviewed for chronic medical conditions including chronic kidney disease, alcoholism, autoimmune conditions, endocrine disorders, elevated alkaline phosphatase levels, history of otitis media, purified protein derivative positivity, history of head and neck surgery and radiation, and human immunodeficiency virus infection. Motion-limited studies and patients with limited clinical data were excluded. Statistical analyses were performed using the independent sample t test and Fisher exact test. RESULTS: Ten (0.6%) of 1571 patients had torus tubarius calcification, of which 7 (70%) were unilateral, and 3 (30%) were bilateral calcification. There was no significant association between torus tubarius calcification and common medical disorders including endocrine disorders, human immunodeficiency virus, chronic kidney disease, alcoholism, purified protein derivative positivity, history of head and neck surgery or radiation, and autoimmune diseases. CONCLUSIONS: Based on the largest series to date on an unrestricted population using thin-section CT imaging, calcification of the torus tubarius is a rare entity with an overall prevalence of 0.6%. Although the clinical significance remains uncertain, there is no significant association between torus tubarius calcification and common medical conditions.

Quantitative Analysis of Extracranial Arterial Tortuosity in Patients with Sickle Cell Disease.

PURPOSE: Compared to the intracranial vasculature in sickle cell disease (SCD) patients, the morphologic changes of the extracranial vasculature in SCD patients are less well understood. The purpose of this study was to evaluate the tortuosity of the extracranial carotid and vertebral arteries in patients with SCD compared to age-matched controls. METHODS: Following Institution Review Board approval, between January 2004 and December 2013, Magnetic resonance angiogram neck examinations were retrospectively reviewed on 56 patients with SCD and 56 age-matched controls. Vessel tortuosity was measured as curved vector lengths in the common carotid, extracranial internal carotid, and vertebral arteries bilaterally. Correlation of vessel tortuosity with age and hematocrit level was assessed. Paired and unpaired Student's t-tests were performed to determine within and between group differences. RESULTS: Greater tortuosity in extracranial carotid and vertebral arteries were noted in patients with SCD as compared to age-matched control patients (P < .001). Greater differences in tortuosity between carotid and vertebral arteries were noted in SCD patients as compared to differences in control patients. Incidence of infarction was significantly associated with greater tortuosity of right carotid (P = .002), right (P = .004), and left (P = .020) vertebral arteries. CONCLUSIONS: Extracranial carotid and vertebral arterial tortuosity is increased in SCD patients. This could be related to aberrations in hemodynamics from nonlaminar flow in these vessels. These increases in extracranial vascular tortuosity could potentially lead to alterations in intracranial vascular tortuosity and may be an independent risk factor for cerebral infarct.

Sarcoidosis in the Head and Neck: An Illustrative Review of Clinical Presentations and Imaging Findings.

OBJECTIVE: Sarcoidosis is referred to as a great imitator because of its propensity to radiologically mimic a variety of pathologic entities. Symptomatic neurosarcoidosis is present in approximately 5% of patients with sarcoidosis, and it is found histopathologically in approximately 25% of asymptomatic patients. CONCLUSION: An understanding of the multifaceted imaging manifestations of head and neck sarcoidosis will aid early recognition of the diagnosis, with a goal for earlier initiation of therapy and prevention of irreversible sequelae of the disease.

Variability in the Cross-Sectional Area and Narrowing of the Internal Jugular Vein in Patients Without Multiple Sclerosis.

OBJECTIVE: Chronic cerebrospinal vascular insufficiency is a proposed condition of intraluminal stenosis of the internal jugular vein (IJV) that impedes venous flow from the brain. Calculations of IJV stenosis are vague and described in veins with at least a 50% reduction in IJV caliber at a specific level. The purpose of this study was to assess normal changes in anatomic caliber of the course of the IJV in a generalized population. MATERIALS AND METHODS: Images from 500 consecutive contrast-enhanced neck CT studies performed in January-July 2011 were reviewed. Cross-sectional areas of the IJV were calculated at the jugular foramen, C1-C7 levels, and jugular angles bilaterally. Patients were excluded if they had severely motion-limited studies; limited clinical data; a history of multiple sclerosis, neck mass, or neck dissection; or known IJV occlusion. Normalized IJV cross-sectional areas at each level were compared with an averaged normalized cross-sectional area from all patients at each level. RESULTS: Greater than 50% narrowing compared with a normalized average was found in 133 of 363 patients (36.6%) and was seen at all IJV levels. In 36.1% of patients this narrowing occurred at the C1 level. Most of the areas of narrowing greater than 50% occurred above the C4 level. CONCLUSION: The IJV has marked variability in its course in the neck. Areas of narrowing greater than 50% occur most commonly in the upper cervical and skull base regions. Given the normal anatomic variations in IJV caliber, caution should be used when making the diagnosis of and treating IJV stenosis.

Unifocal versus multifocal mandibular fractures and injury location.

Mandibular fractures are frequently encountered in the trauma setting and comprise a significant number of facial injuries. The purpose of this study was to evaluate the prevalence and injury patterns of unifocal and multifocal mandibular fractures using thin-section imaging. Following IRB approval, 220 patients with mandibular fractures identified on maxillofacial CT scans performed between October 2008 and February 2011 were retrospectively reviewed. Examinations were performed on 64-multidetector row CT scanners with axial images acquired at 1.25-mm slice thickness. The location and number of fractures as well as causative mechanisms were recorded. Fractures were unifocal in 108/220 (49 %) and multifocal in 112/220 (51 %) patients. The mandibular angle was the most common fracture site in both unifocal and multifocal mandible fractures. In cases with multifocal mandibular fractures, bilateral fractures were more common (83 %) than unilateral multifocal mandibular fractures (17 %). Fractures involving the parasymphysis, the mandibular body, or ramus were significantly associated with the presence of additional mandibular fractures (p < 0.0001). While multifocal and unifocal fractures occurred in near equal frequency, bilateral multifocal fractures were much more common than unilateral multifocal mandibular fractures. Alveolar ridge fractures were exclusively seen in unifocal mandibular fractures.

Clinical associations of incidentally detected parotid gland calcification on CT.

OBJECTIVES/HYPOTHESIS: Parotid gland calcifications can be incidental findings on computed tomography (CT) and have been reported to be associated with chronic inflammatory conditions. Associations between parotid gland calcification and other common medical conditions have not been reported. METHODS: Following institutional review board approval, 1,571 patients who underwent noncontrast head CT with 1.25-mm slice thickness on a 64-detector row CT between January 2011 and July 2011 were retrospectively reviewed for parotid gland calcifications. Medical records were reviewed for chronic kidney disease, alcoholism, autoimmune conditions, endocrine disorders, elevated alkaline phosphatase, and HIV (human immunodeficiency virus) status. Statistical analyses were performed using Fisher's exact test and multiple logistic regression. RESULTS: Sixty-three of 1,571 (4%) patients had parotid gland calcifications. Significant associations were observed between parotid gland calcifications and HIV infection (P = 0.002), chronic kidney disease (P < 0.0001), alcoholism (P < 0.0001), elevated alkaline phosphatase (P = 0.003), and autoimmune disease (P = 0.02). CONCLUSION: Parotid gland calcifications were associated with HIV, alcoholism, chronic kidney disease, autoimmune disease, and elevated alkaline phosphatase. LEVEL OF EVIDENCE: 4.

Granulomatous disease in the head and neck: developing a differential diagnosis.

Granulomatous diseases have a varied etiology that includes autoimmune, infectious, idiopathic, and hereditary causes. The unifying factor in these diseases is the formation of granulomas, which histologically are mononuclear inflammatory cells or macrophages surrounded by lymphocytes. Granulomatous diseases often have systemic manifestations that affect organs throughout the body. Granulomatous diseases with head and neck manifestations include granulomatosis with polyangiitis, Churg-Strauss syndrome, Behçet disease, chronic granulomatous disease, and sarcoidosis. Infectious causes include tuberculosis, cat-scratch disease, syphilis, leprosy, actinomycosis, rhinoscleroma, and fungal infections. In the head and neck, granulomatous disease may affect the orbits, sinonasal cavities, salivary glands, aerodigestive tract, temporal bone, or skull base. Imaging findings include sinonasal opacification, ocular and other soft-tissue masses, osseous erosion, airway narrowing, lymphadenopathy, and salivary gland infiltration. Vascular involvement may also be evident, with displacement, narrowing, or occlusion of arteries and veins. Some radiologic findings of granulomatous processes have a considerable overlap with findings of malignancy, and a radiologic differential diagnosis inclusive of both is critical to avoid incorrect clinical treatment. Without the benefit of a prior clinical diagnosis, laboratory findings, or suggestive clinical signs and symptoms, granulomatous diseases may be difficult to differentiate radiologically. Although individual granulomatous diseases may have overlapping findings at imaging, certain radiologic findings should prompt the inclusion of granulomatous diseases in the differential diagnosis, thus facilitating appropriate clinical management.

Injuries of the globe: what can the radiologist offer?

Traumatic ocular injuries are a significant cause of blindness and visual deficits. In the setting of acute orbital trauma, urgent ophthalmologic evaluation and intervention are critical in preserving vision. However, in the acute trauma setting, clinical evaluation of the globe may be difficult in the presence of surrounding periorbital soft-tissue swelling and other associated injuries, and patient cooperation may be limited because of unresponsiveness, altered mentation, or sedation. Often, rapid access to imaging is part of the initial diagnostic evaluation, and radiologists may be the first to identify traumatic injuries of the globe. Because of this, radiologists should be familiar with normal orbital and globe anatomy at various imaging modalities and have a thorough understanding of the various patterns of ocular injury and their imaging appearances. Radiologists should also be familiar with the various mimics of ocular injury, including congenital and acquired conditions that may alter the shape of the globe, various types of ocular calcifications, and the different types of material used to treat retinal detachment. Such knowledge may help radiologists make accurate diagnoses, which facilitates prompt and appropriate patient care.