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Radiologia , Humanos , Zâmbia , Radiologia/educação , Currículo , Radiografia , ComputadoresRESUMO
Paragangliomas are neuroendocrine tumors that derive from paraganglia of the autonomic nervous system, with the majority of parasympathetic paragangliomas arising in the head and neck. More than one-third of all paragangliomas are hereditary, reflecting the strong genetic predisposition of these tumors. The molecular basis of paragangliomas has been investigated extensively in the past couple of decades, leading to the discovery of several molecular clusters and more than 20 well-characterized driver genes (somatic and hereditary), which are more than are known for any other endocrine tumor. Head and neck paragangliomas are largely related to the pseudohypoxia cluster and have been previously excluded from most molecular profiling studies. This review article introduces the molecular classification of paragangliomas, with a focus on head and neck paragangliomas, and discusses its impact on the management of these tumors. Genetic testing is now recommended for all patients with paragangliomas to provide screening and surveillance recommendations for patients and relatives. While CT and MRI provide excellent anatomic characterization of paragangliomas, gallium 68 tetraazacyclododecane tetraacetic acid-octreotate (ie, 68Ga-DOTATATE) has superior sensitivity and is recommended as first-line imaging in patients with head and neck paragangliomas with concern for multifocal and metastatic disease, patients with known multifocal and metastatic disease, and in candidates for targeted peptide-receptor therapy. Keywords: Molecular Imaging, MR Perfusion, MR Spectroscopy, Neuro-Oncology, PET/CT, SPECT/CT, Head/Neck, Genetic Defects © RSNA, 2022.
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Neoplasias de Cabeça e Pescoço , Paraganglioma Extrassuprarrenal , Paraganglioma , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Imageamento por Ressonância Magnética , Paraganglioma/diagnóstico por imagem , Paraganglioma/genética , Paraganglioma/terapia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , CintilografiaRESUMO
Unfortunately, the original publication of this article contained a mistake in Fig. 7a. The correct figure is presented here. The original article has been corrected.
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The differential diagnosis of a masticator space (MS) lesion is broad, owing in part to the multiple structures contained within such a small region. It is also because the MS is adjacent to many of the other deep spaces within the head and neck, which can act as gateways for disease spread. Therefore, emergency radiologists must be familiar with anatomy of the MS, as well as adjacent spaces in order to provide an accurate diagnosis to the referring clinician. This article illustrates the anatomy and common pathologies within the MS using a case-based multimodality approach. Common masticator space pathologies can be categorized into inflammatory/infectious, neoplastic, and vasoformative lesions. Important imaging features of MS lesions and patterns of disease spread will be discussed, with the aim of making this complex deep space more approachable in the emergent setting.
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Imagem Multimodal , Doenças Estomatognáticas/diagnóstico por imagem , Anormalidades do Sistema Estomatognático/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Sistema Estomatognático/anatomia & histologiaRESUMO
The differential diagnosis for hoarseness is extensive and includes a multitude of etiologies that span a large geographic area from the brainstem to the mediastinum. Therefore, localizing a causative lesion can be extremely difficult for clinicians and radiologists alike. In this review, we will first discuss the normal anatomy of the larynx and its innervation via the vagus and recurrent laryngeal nerves. We will then proceed with a guided tour of the various infectious/inflammatory, neoplastic, congenital, and traumatic/iatrogenic causes of hoarseness subdivided by anatomic location (brainstem, skull base, carotid sheath, thyroid, larynx, and superior mediastinum). Along the way, we will discuss the various cross-sectional imaging modalities best suited to detect the often subtle signs of recurrent laryngeal nerve injury. With thorough knowledge of these entities, radiologists can impact patient care by suggesting the appropriate imaging test and tailoring their search patterns to detect the subtle findings of laryngeal dysfunction.
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BACKGROUND: Percutaneous trigeminal rhizotomy or balloon compression for trigeminal neuralgia carries a potential risk for the brainstem, the carotid artery, and the basilar artery. OBJECTIVE: To detail the relation of critical neural and vascular structures to expanded balloons used for percutaneous compression of the trigeminal ganglion. METHOD: A retrospective analysis of preprocedural magnetic resonance imaging (MRI) and procedural X-ray-based imaging for 9 patients detailed balloon proximity to the brainstem, carotid artery, and basilar artery. RESULTS: Balloons extended 10.96 ± 5.54 mm (mean ± SD) posterior to the clival line. The average distance from the balloon to the brainstem was 6.89 mm, and that to the basilar artery was 12.12 mm (range: 0-18.2). The medial edge of the balloon was an average distance of 1.39 mm from the baseline position of the carotid lumen. CONCLUSION: Preprocedural MRI, merged with 3-D rotational angiography suite imaging, detailed the proximity of the balloon to critical neural and vascular structures. Our study found that the standard technique for percutaneous trigeminal compression, with balloon placement at an average depth of 10.96 mm posterior to the clival line, on average, provided an additional 6.89 mm of space before the brainstem would have been encountered, demonstrating safe positioning.
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Cateterismo/métodos , Neuralgia do Trigêmeo/cirurgia , Idoso , Idoso de 80 Anos ou mais , Artéria Basilar/diagnóstico por imagem , Tronco Encefálico/diagnóstico por imagem , Artérias Carótidas/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neuralgia do Trigêmeo/diagnóstico por imagem , Raios XRESUMO
This article focuses on the imaging of 5 discrete entities with a common end result of disability: posttraumatic arthritis, a common form of secondary osteoarthritis that results from a prior insult to the joint; avascular necrosis, a disease of impaired osseous blood flow, leading to cellular death and subsequent osseous collapse; septic arthritis, an infectious process leading to destructive changes within the joint; complex regional pain syndrome, a chronic limb-confined painful condition arising after injury; and cases of cancer mimicking arthritis, in which the initial findings seem to represent arthritis, despite a more insidious cause.
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Artrite/diagnóstico por imagem , Síndromes da Dor Regional Complexa/diagnóstico por imagem , Diagnóstico por Imagem/métodos , Articulações/lesões , Osteonecrose/diagnóstico por imagem , Artrite Infecciosa/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Articulações/diagnóstico por imagem , NeoplasiasRESUMO
OBJECTIVE: The aim of the study was to analyze the sonographic features of nodular Hashimoto thyroiditis (HT) in patients with diffuse background thyroiditis and normal background thyroid parenchyma. SUBJECTS AND METHODS: Eighty-six patients who had fine-needle aspiration biopsy of 100 thyroid nodules confirmed to be HT and a thyroid ultrasound within 1 year of the biopsy were included in the study. Retrospective analysis of several sonographic features of each nodule was then performed. RESULTS: The mean age of patients with nodular HT was 53 years, 84% of which were female. Nodular HT occurred in a background of diffuse thyroiditis in 85% and in a homogeneous normal background in 15%. Ninety-three percent of nodules were completely solid and 7% of nodules were cystic and solid. Although the sonographic appearance of nodular HT was variable, the most common appearance was a solid (93/100) and hypoechoic nodule (44/100) with a thin hypoechoic halo (42/100) without calcifications (96/100). On color Doppler, 17% of nodules showed peripheral hypervascularity, 14% of nodules were diffusely hypervascular, 34% were iso vascular, 32% were hypovascular, and 3% were avascular. The sonographic appearance of nodular HT was not significantly different in patients with diffuse background thyroiditis compared with those without background thyroiditis. CONCLUSIONS: The sonographic appearance of nodular HT is variable, but the most common appearance is a solid sharply circumscribed hypoechoic nodule with thin hypoechoic halo without calcification. There was no significant difference in the appearance of nodular HT in patients with diffuse background thyroiditis compared with patients with normal background thyroid parenchyma.
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Doença de Hashimoto/diagnóstico por imagem , Nódulo da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Glândula Tireoide/diagnóstico por imagemRESUMO
BACKGROUND: We report a case of a large giant cell tumor of the thoracic spine presenting with spinal cord compression during pregnancy. CASE: A 24-year-old woman presented at term with lower back pain, bilateral lower extremity weakness, numbness, and bowel and bladder incontinence. Magnetic resonance imaging revealed a spinal soft tissue mass compressing the spinal cord. The patient delivered a healthy girl by cesarean then underwent a T8-T9 laminectomy, posterior spinal decompression, and instrument fusion. Two days later, she had a thoracotomy, corpectomy of the vertebral body, and anterior tumor debulking. Ultimately, the patient was discharged to inpatient rehabilitation with improved lower extremity strength and returned bowel and bladder function. CONCLUSION: Obstetricians should be vigilant regarding progressive neurologic symptoms during pregnancy.
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Neoplasias Ósseas/diagnóstico , Tumor de Células Gigantes do Osso/diagnóstico , Paresia/diagnóstico , Complicações Neoplásicas na Gravidez/diagnóstico , Compressão da Medula Espinal/diagnóstico , Neoplasias Ósseas/reabilitação , Neoplasias Ósseas/cirurgia , Cesárea , Descompressão Cirúrgica , Incontinência Fecal/diagnóstico , Incontinência Fecal/reabilitação , Incontinência Fecal/cirurgia , Feminino , Tumor de Células Gigantes do Osso/reabilitação , Tumor de Células Gigantes do Osso/cirurgia , Humanos , Recém-Nascido , Laminectomia , Imageamento por Ressonância Magnética , Paresia/reabilitação , Paresia/cirurgia , Gravidez , Complicações Neoplásicas na Gravidez/reabilitação , Complicações Neoplásicas na Gravidez/cirurgia , Compressão da Medula Espinal/reabilitação , Compressão da Medula Espinal/cirurgia , Fusão Vertebral , Toracotomia , Resultado do Tratamento , Incontinência Urinária/diagnóstico , Incontinência Urinária/reabilitação , Incontinência Urinária/cirurgia , Adulto JovemRESUMO
The integral membrane protein prestin, a member of the SLC26 anion transporter family, is responsible for the voltage-driven electromotility of mammalian outer hair cells. It was argued that the evolution of prestin's motor function required a loss of the protein's transport capabilities. Instead, it was proposed that prestin manages only an abortive hemicycle that results in the trapped anion acting as a voltage sensor, to generate the motor's signature gating charge movement or nonlinear capacitance. We demonstrate, using classical radioactive anion ([(14)C]formate and [(14)C]oxalate) uptake studies, that in contrast to previous observations, prestin is able to transport anions. The prestin-dependent uptake of both these anions was twofold that of cells transfected with vector alone, and comparable to SLC26a6, prestin's closest phylogenetic relative. Furthermore, we identify a potential chloride-binding site in which the mutations of two residues (P328A and L326A) preserve nonlinear capacitance, yet negate anion transport. Finally, we distinguish 12 charged residues out of 22, residing within prestin's transmembrane regions, that contribute to unitary charge movement, i.e., voltage sensing. These data redefine our mechanistic concept of prestin.