Akifumi Fujita

Cervical spine movement during laryngoscopy using the Airway Scope compared with the Macintosh laryngoscope

The Airway Scope is a new rigid laryngoscope. This intubation device provides a non‐line‐of sight view of the glottis. A non‐line‐of sight view is expected to cause less movement of the cervical spine during laryngeal visualisation. We compared the degree of cervical spine movement during laryngoscopy with the Airway Scope and conventional direct laryngoscope. Twenty patients requiring general anaesthesia and tracheal intubation were studied. Movements of the cervical spine were measured using radiography in the same patient during laryngoscopy with the Airway Scope and a Macintosh laryngoscope. Cervical spine movement during laryngoscopy with the Airway Scope was 37%, 37% and 68% less than that with the Macintosh laryngoscope at the C0/C1, C1/C2 and C3/C4 motion segments, respectively (p < 0.05). The movement of the atlanto‐occipital distance using the Airway Scope was 42% less than that during laryngoscopy using the Macintosh laryngoscope (p < 0.05). Laryngoscopy using the Airway Scope involves less movement of the cervical spine compared to conventional laryngoscopy using the Macintosh laryngoscope.

IgG4-related Disease of the Head and Neck: CT and MR Imaging Manifestations

Immunoglobulin G4 (IgG4)-related disease is a recently established systemic disease that commonly involves the head and neck, including the salivary glands, lacrimal glands, orbits, thyroid gland, lymph nodes, sinonasal cavities, pituitary gland, and larynx. Although the definitive diagnosis of IgG4-related disease requires histopathologic analysis, elevated serum IgG4 levels are helpful in making the diagnosis. Because of the proposed clinical diagnostic criteria for this disease, cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance (MR) imaging play an important diagnostic role. CT and MR imaging findings of IgG4-related disease are usually nonspecific. At CT, involved organs may demonstrate enlargement or decreased attenuation; at T2-weighted MR imaging, they may have relatively low signal intensity owing to their increased cellularity and amount of fibrosis. Some pathologic entities involving the head and neck are now considered to be part of the IgG4-related disease spectrum, including idiopathic orbital inflammatory syndrome (inflammatory pseudotumor), orbital lymphoid hyperplasia, Mikulicz disease, Küttner tumor, Hashimoto thyroiditis, Riedel thyroiditis, and pituitary hypophysitis. Because involvement of multiple sites is common in IgG4-related disease, radiologists should be familiar with manifestations of this systemic process outside the head and neck, in organs such as the pancreas, bile ducts, gallbladder, kidneys, retroperitoneum, mesentery, lungs, gastrointestinal tract, and blood vessels. Moreover, IgG4-related disease usually demonstrates a dramatic response to corticosteroid therapy, and radiologists should be familiar with its clinical and imaging manifestations to avoid a delay in diagnosis or unnecessary invasive interventions.

A comparison of cervical spine movement during laryngoscopy using the Airtraq or Macintosh laryngoscopes.

The Airtraq® laryngoscope has an oropharyngeal airway‐shaped blade that provides a non‐line‐of‐sight view of the glottis. The configuration of the blade should mean that less movement of the cervical spine is required during laryngeal visualisation.

Stable and convenient spatial registration of stand-alone NIRS data through anchor-based probabilistic registration

For functional neuroimaging with near-infrared spectroscopy (NIRS), we recently introduced a probabilistic registration method that uses a reference magnetic resonance image (MRI) database instead of the subjects own MRI, and probabilistically registers the NIRS optode or channel positions onto a canonical brain template in the standard stereotactic brain coordinate systems. As an alternative method, we devised an anchor-based registration method utilizing roughly obtained anchor positions on the scalp instead of strictly defined landmarks such as 10/20 landmarks. This method uses a spherical coordinate system to seek a position in the reference MRI database that corresponds to the anchor position, and eventually presents NIRS optode and channel positions in the standard stereotactic brain coordinate system. For comparison against conventional probabilistic registration, we simulated NIRS optode holder placement on 100 synthesized virtual heads, and found holistic tendencies for probe position estimations were similar between the two methods. Comparison among anchor-based probabilistic registration, conventional probabilistic registration, and SPM-based registration via co-registration to a subjects own MRI revealed that intra-method variability was comparable to a small inter-method variability. Thus, anchor-based registration is a practical alternative, especially to avoid burdening a subject and to reduce experimental time.

Use of fusion images of I-131 metaiodobenzylguanidine, SPECT, and magnetic resonance studies to identify a malignant pheochromocytoma.

Pheochromocytoma is a chromaffin tumor in which 10% are extra-adrenal and 10% are malignant. I-131 metaiodobenzylguanidine (MIBG) scintigraphy has an important role in the identification of these tumors and investigation of metastatic lesions. The authors describe a 36-year-old woman who underwent resection of a malignant left adrenal pheochromocytoma who was thought to have metastases in the liver and para-aortic lymph nodes. Fusion images of I-131 MIBG SPECT and magnetic resonance studies were obtained to properly identify the metastatic lesions. These fusion images helped greatly in subsequent surgery.

Using Texture Analysis to Determine Human Papillomavirus Status of Oropharyngeal Squamous Cell Carcinomas on CT

BACKGROUND AND PURPOSE: Human papillomavirus–associated oropharyngeal squamous cell carcinoma is increasing in prevalence and typically occurs in younger patients than human papillomavirus–negative squamous cell carcinoma. While imaging features of human papillomavirus–positive versus human papillomavirus–negative squamous cell carcinoma nodal metastases have been described, characteristics distinguishing human papillomavirus–positive from human papillomavirus–negative primary squamous cell carcinomas have not been well established. The purpose of this project was to evaluate the use of texture features to distinguish human papillomavirus–positive and human papillomavirus–negative primary oropharyngeal squamous cell carcinoma. MATERIALS AND METHODS: Following institutional review board approval, 40 patients with primary oropharyngeal squamous cell carcinoma and known human papillomavirus status who underwent contrast-enhanced CT between December 2009 and October 2013 were included in this study. Segmentation of the primary lesion was manually performed with a semiautomated graphical-user interface. Following segmentation, an in-house-developed texture analysis program extracted 42 texture features from each segmented volume. A t test was used to evaluate differences in texture parameters between human papillomavirus–positive and human papillomavirus–negative squamous cell carcinomas. RESULTS: Of the 40 included patients, 29 had human papillomavirus–positive oropharyngeal squamous cell carcinoma and 11 had human papillomavirus–negative oropharyngeal squamous cell carcinoma. Significant differences were seen in the histogram parameters median (P = .006) and entropy (P = .016) and squamous cell carcinoma entropy (P = .043). CONCLUSIONS: There are statistically significant differences in some texture features between human papillomavirus–positive and human papillomavirus–negative oropharyngeal tumors. Texture analysis may be considered an adjunct to the evaluation of human papillomavirus status and characterization of squamous cell carcinoma.

Difference Between HPV-Positive and HPV-Negative Non-Oropharyngeal Head and Neck Cancer: Texture Analysis Features on CT.

Objective To identify the specific texture parameter that shows significant differences between human papillomavirus (HPV)–positive (HPV+) and HPV-negative (HPV-) non-oropharyngeal carcinoma (non-OPC) using texture analysis. Methods Forty-six patients of non-OPC patients (oral cavity, larynx, and hypopharynx) with known HPV status, who underwent contrast-enhanced computed tomography for initial staging, were retrospectively reviewed. Segmentations of the primary lesion were manually performed, and an in-house developed texture analysis program extracted 42 texture features from each segmented volume. A t test was used to evaluate differences between HPV+ and HPV- non-OPCs (P < 0.05). Results Sixteen texture parameters, including 5 histogram features (P ⩽ 0.03), 3 gray-level co-occurrence matrix features (P ⩽ 0.02), 1 gray-level run-length feature (P = 0.009), 2 gray-level gradient matrix features (P ⩽ 0.02), and 5 Law features (P ⩽ 0.04), showed significant differences. Conclusions Texture analysis demonstrated significant differences between HPV+ and HPV- non-OPCs on computed tomography images, which may have a potential to prove morphologic feature differences among HPV-related tumors.

Otosclerosis: computed tomography and magnetic resonance findings.

A 45-year-old woman presented with bilateral combined hearing loss of 26 years duration. She first noticed slight hearing impairment after a traffic accident when she was 19 years old. Bilateral combined hearing loss had progressed, from age 28, and she had been totally deaf since she was 35 years old. She underwent CT and MR imaging for preoperative evaluation for cochlear implant. CT showed extensive demineralization of the cochlear capsule bilaterally, which is characteristic of diffuse otosclerosis (Fig 1A-C). Spin echo Tl-weighted MR images showed fuzzy, soft tissue signal intensities in the cochlear capsule instead of normal signal void from the bone (Fig 2). Preserved high signal from the membranous labyrinth was seen on fast spin echo T2-weighted images (Fig 3). Otospongiotic lesions were not well appreciated on this sequence, although some signal was appreciated in the otic capsule. There was no evidence of hypoplasia or aplasia of the cochlear nerve. Contrast-enhanced, spin-echo T1-

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.