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.

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.

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.

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.

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.

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.

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.

Nasopharyngeal cystic lesions: Tornwaldt and mucous retention cysts of the nasopharynx: findings on MR imaging.

OBJECTIVE: Nasopharyngeal cystic lesions are commonly encountered on magnetic resonance imaging with significantly overlapped imaging characteristics. The purpose of this study was to determine the prevalence and distinguishing imaging features of cystic lesions in the nasopharynx in the largest patient series to date. METHODS: After institutional review board approval, consecutive head magnetic resonance images of 3000 patients performed at 1.5 T between June 2010 and April 2011 were retrospectively reviewed for cystic nasopharyngeal lesions. Location, size, and signal characteristic of cystic lesions were recorded. Electronic medical records were reviewed for patient demographics, symptoms, and underlying conditions. RESULTS: Among 3000 patients, 6% had Tornwaldt cysts (peak prevalence, 51-60 years old) and 10% had mucous retention cysts (peak prevalence, 41-50 years old). A significant correlation between human immunodeficiency virus infection and mucous retention cysts was observed (P < 0.001). CONCLUSIONS: The prevalence of Tornwaldt cysts was slightly higher than previously described in the literature. Additionally, younger and older patients had the lowest prevalence of Tornwaldt cyst, suggesting these lesions are acquired and subsequently involute with time. A significant correlation was observed between human immunodeficiency virus infection and mucous retention cysts.

Quantitative magnetic resonance imaging analysis of the lacrimal gland in sickle cell disease.

OBJECTIVES: Clinical manifestations of sickle cell disease (SCD) can affect the orbit with prior reports describing changes in the lacrimal gland potentially related to chronic vaso-occlusion. The purpose of this study was to evaluate lacrimal gland volumes and quantifiable shifts in MR-relaxation times in patients with SCD. METHODS: Thirteen patients with SCD and 12 age-matched control subjects underwent magnetic resonance imaging (MRI) of the orbits with 1.5-T MRI. Lacrimal glands were segmented manually; and gland volumes, peak, and mean T1- and T2-relaxation times were obtained from histogram analysis. RESULTS: In patients with SCD, significant peak and mean T2 shortening (P < 0.001 and P < 0.001) and increased gland volume (P = 0.008) were observed. Significant correlations were seen between gland volumes in the patients SCD and peak T1 and T2 values (r = 0.6, P = 0.017; r = 0.56; P = 0.031) as well as between gland volumes and mean T1 and T2 values (r = 0.54, P = 0.039; r = 0.57, P = 0.026). CONCLUSION: Significant differences in MR relaxometry and lacrimal gland enlargement provide evidence of subclinical lacrimal gland pathology and chronic lacrimal gland changes patients with SCD.

qMRI relaxometry of mandibular bone marrow: a monomodal distribution in sickle cell disease.

PURPOSE: To identify and characterize sickle cell disease (SCD)-related changes in the composition of mandibular bone marrow using qMRI relaxometry histograms. MATERIALS AND METHODS: Thirteen SCD patients and 17 controls underwent brain MR imaging with the mixed turbo spin-echo (TSE) pulse sequence at 1.5T. The mandible was manually segmented and divided into body, angle, ramus, and condyle. T1 and T2 histograms of each mandible were modeled with Gaussian functions. The relaxation time histogram peaks were calculated, and the number of monomodal versus bimodal curves was compared. RESULTS: SCD patients exhibited monomodal distributions on both T1 and T2 histograms, consistent with a composition of predominantly red hematopoietic marrow. Eighty-eight percent of mandibles in control subjects exhibited a bimodal distribution in T1 and all showed a bimodal distribution in T2, indicating mixed but predominantly yellow marrow composition. The second peak in control subjects was shorter in T1 and longer in T2, consistent with yellow marrow composition. CONCLUSION: Instead of physiological fatty replacement, SCD patients exhibit red marrow persistence in the mandible, likely due to the increased demand for hematopoiesis. This phenomenon can be manifested by a monomodal curve in both T1 and T2 relaxometric histograms.

Periapical lucency around the tooth: radiologic evaluation and differential diagnosis.

Periapical lucencies are often seen incidentally at head and neck imaging studies performed for indications not related to the teeth. These lesions are, however, occasionally manifestations of diseases that have a wide range of effects and may at times represent the source of symptoms that prompted the study. The vast majority of periapical lucencies are the result of apical periodontal or pulpal disease. If found in an advanced state or left untreated, disease related to the tooth may spread to adjacent tissues, including the sinuses, orbits, deep fascial spaces of the neck, and intracranial structures, and result in a significant increase in patient morbidity and mortality. Although the majority of periapical lucencies seen on radiographs and computed tomographic images occur secondary to apical periodontal or pulpal disease, not all lucencies near the tooth root are due to infection. Lucency near the tooth root may be seen in the setting of other diseases of odontogenic and non-odontogenic origin, including neoplasms. Although imaging findings for these lesions can include periapical lucent components, awareness of the varied secondary imaging features can aid the radiologist in developing an accurate differential diagnosis. Familiarity with the imaging features and differential diagnoses of diseases or conditions that cause lucency around the tooth root results in appropriate referral and prompt diagnosis, management, and treatment, and can prevent unnecessary additional imaging or intervention. In addition, early recognition and appropriate treatment of infectious processes will result in improved clinical outcomes and a decrease in morbidity and mortality.

Craniofacial bone infarcts in sickle cell disease: clinical and radiological manifestations.

OBJECTIVE: To investigate the clinicoradiological manifestations of craniofacial bone infarcts in patients with sickle cell disease (SCD). MATERIALS AND METHODS: After institutional review board approval, we identified 85 SCD patients who underwent head and neck magnetic resonance imaging (MRI) during a period of 5 years (January 1, 2004-December 31, 2008) and reviewed their clinical presentations and radiological findings. RESULTS: Of 40 subjects with headache or facial pain, 6 (5 males, 1 female; age range, 2-22 years; 5 Hb SS, 1 Hb SC) were diagnosed with acute bone infarct by MRI. Of these 6, 4 demonstrated infarcts in the mandible. Magnetic resonance images showed bone marrow edema, subperiosteal fluid collections with susceptibility effects suggesting associated hemorrhage, and heterogeneous enhancement. CONCLUSIONS: Acute craniofacial bone infarcts were found in 7% of SCD patients who underwent MRI and in 15% of SCD patients who presented with pain. The MRI showed characteristic imaging findings including marrow edema, subperiosteal hematoma, and heterogeneous enhancement.

Imaging of cervical lymphadenopathy in children and young adults.

OBJECTIVE: This article describes the role of imaging in evaluating cervical lymphadenopathy in patients from birth to their mid-20s, illustrates imaging features of normal and abnormal lymph nodes, and highlights nodal imaging features and head and neck findings that assist in diagnosis. CONCLUSION: Cervical lymph node abnormalities are commonly encountered clinically and on imaging in children and young adults. Although imaging findings can lack specificity, nodal characteristics and associated head and neck imaging findings can assist in determining the underlying cause.

Posttreatment CT and MR imaging in head and neck cancer: what the radiologist needs to know.

In patients with head and neck cancer, posttreatment imaging can be complicated and difficult to interpret because of the complexity of the surgical procedures performed and the postirradiation changes, but such imaging is critical for the evaluation of (a) the response to therapy and (b) tumor control. Posttreatment changes are affected by the type of surgery performed, reconstruction, neck dissection, and radiation therapy. Three types of flaps are used for reconstruction in the head and neck region: (a) the local flap, with geometric repositioning of adjacent tissue; (b) the pedicle flap, with rotation of donor tissue and preservation of the original vascular system; and (c) the free flap, with transfer of tissue that is revascularized by using microvascular surgical techniques. The posttreatment imaging findings in patients with head and neck cancer can be divided into four groups: altered anatomy secondary to surgical reconstruction, tumor recurrence, potential postsurgical complications, and possible postirradiation changes. Potential postsurgical complications are wound infection, abscess, fistula, flap necrosis, hematoma, chylous fistula, and serous retention. Possible postirradiation changes include mucosal necrosis, osteoradionecrosis, radiation-induced vasculopathy, radiation pneumonitis, radiation lung fibrosis, radiation-induced brain necrosis, and radiation-induced secondary malignancies. A familiarity with the imaging characteristics of posttreatment changes and of the potential complications caused by surgery and irradiation and an ability to differentiate these findings from tumor recurrence are essential for posttreatment surveillance and follow-up management of patients with head and neck cancer.

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.

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.

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.

Clinical and radiologic manifestations of sickle cell disease in the head and neck.

Sickle cell disease is a common inherited blood disorder that is characterized by the presence of sickle-shaped red blood cells. The clinical manifestations of sickle cell disease vary, but they may be attributed to three mechanisms: vaso-occlusion, chronic hemolytic anemia, and infection. The imaging appearances of central nervous system and musculoskeletal involvement by sickle cell disease have been well documented; however, involvement in the head and neck often is underappreciated, although it is not uncommon. In the head and neck, sickle cell disease can involve the inner ears, orbits, paranasal sinuses, bones, lymph nodes, and vessels. Manifestations of inner ear involvement include labyrinthine hemorrhage and labyrinthitis ossificans. In the orbits, they include lacrimal gland swelling, orbital wall infarction, and subperiosteal hemorrhage or fluid. In the paranasal sinuses, extramedullary hematopoiesis is seen. When bone is involved, infarction, osteomyelitis, bone marrow hyperplasia, and deposition of iron in bone marrow are seen in the maxillofacial bone and skull base. When lymph nodes are involved, lymphadenopathy is seen, and when blood vessels are involved, arterial stenosis and ectasia are seen. An understanding of the pathophysiology of sickle cell disease and knowledge of the various clinical and radiologic manifestations are crucial for prompt diagnosis and appropriate treatment.