The aim of this study is to review the anatomy and main pathologic conditions affecting cranial nerve III using imaging studies, particularly magnetic resonance imaging. Imaging methods are essential in the evaluation of patients with suspected lesions of the oculomotor nerve once signs and symptoms are unspecific and a large number of diseases can affect cranial nerve III. A brief review of the literature is also presented.

Keywords: Isolated disfunction of oculomotor nerve, Computed tomography, Magnetic resonance imaging

Fibrolipomatous hamartoma of nerve and macrodystrophia lipomatosa are rare conditions that present characteristic imaging findings. The plain films, magnetic resonance imaging studies and medical records of four patients were reviewed. The lesion was resected in one patient allowing histological confirmation of the diagnosis. Diagnosis was based on imaging and clinical findings in three patients who had unavailable biopsy data. We describe two cases of isolated macrodystrophia lipomatosa, one case of fibrolipomatous hamartoma and one case where both conditions were found. In the macrodystrophia lipomatosa cases plain films demonstrated enlargement of osseous and soft tissue structures in the affected limbs, with fatty streaks interspersed along the muscle fibers. The median nerve was affected in the cases of fibrolipomatous hamartoma. Magnetic resonance imaging findings included nerve fascicle thickening characterized by low signal on both T1 and T2-weighted sequences, and surrounding fat, which appears as high signal on T1 and low signal on T2-weighted sequences with fat saturation. Both nerves had a "coaxial cable" appearance on axial images. The fibrolipomatous hamartoma extended to the nerve branches, which is a typical finding. The typical imaging findings of macrodystrophia lipomatosa and fibrolipomatous hamartoma of nerve, particularly at magnetic resonance imaging examination, allowed a reliable diagnosis of these frequently coexistent conditions.

Keywords: Macrodystrophia lipomatosa, Fibrolipomatous hamartoma, Magnetic resonance imaging, Peripheral nerve disease, Median nerve

Objetivo: A principal utilidade da tomografia por emissão de pósitrons com 18-fluordeoxiglicose (FDG-PET) está no estadiamento do câncer de pulmão. Porém, ela também pode ser utilizada para diferenciar lesões pulmonares indeterminadas, mas seu impacto na ressecção cirúrgica de lesões benignas é desconhecido. O objetivo deste estudo foi comparar a prevalência de lesões benignas em toracotomias feitas por suspeição de câncer de pulmão, antes e após a introdução do FDG-PET, em um centro de referência de cirurgia torácica. Materiais e Métodos: Os autores analisaram, prospectivamente, uma base de dados cirúrgicos de todos os pacientes consecutivos submetidos a toracotomia por câncer de pulmão suspeito ou comprovado e compararam a prevalência de lesões benignas em dois grupos ao longo de dois anos consecutivos, respectivamente antes (grupo I) e depois (grupo II) da introdução da FDG-PET. Resultados: Ressecção cirúrgica foi feita em 1.233 pacientes durante o período do estudo. A prevalência de lesões benignas na cirurgia nos grupos I e II foi similar (44/626 e 41/607, ambas correspondendo a 7%), e também no grupo II, entre aqueles submetidos a FDG-PET e os restantes (21/301 e 20/306 respectivamente, ambos correspondendo a 7%). No grupo II, dos 21 pacientes com lesões benignas submetidos a FDG-PET, 19 tiveram um estudo falso-positivo (valor médio padrão de captação 5.3 [faixa 2.6–12.7]). Desses, respectivamente 13 e 4 pacientes tiveram broncoscopia não diagnóstica e biópsia transtorácica percutânea de pulmão antes da toracotomia. Não houve diferença na proporção de lesões benignas diferentes ressecadas entre o grupo I e aqueles submetidos a FDG-PET no grupo II. Conclusão: A introdução da FDG-PET não alterou a proporção de pacientes submetidos a toracotomia por lesões benignas, principalmente devido à avidez pelo isótopo de algumas lesões não malignas. Tais resultados falsos-positivos devem ser considerados nos casos em que se contempla a possibilidade de ressecção cirúrgica em pacientes com câncer de pulmão não confirmado.

Keywords: Tomografia por emissão de pósitrons; Tomografia computadorizada; Pulmão – lesões benignas ou congênitas; Câncer de pulmão – diagnóstico e estadiamento; Câncer de pulmão – cirurgia.

OBJETIVO: Avaliar a completude das fissuras, resposta radiológica ao tratamento e análise quantitativa por TC (AQTC) em população de pacientes com enfisema grave submetidos ao implante de valvas endobrônquicas (VEB). MATERIAIS E MÉTODOS: Foram estudados exames de TC multidetectores de 29 pacientes, realizados com protocolo de baixo dose, cortes finos, sem contraste. Dois radiologistas revisaram, retrospectivamente, os exames em consenso. A completude das fissuras foi estimada em escala de 5% e a resposta radiológica (atelectasia/perda volumétrica do lobo alvo) foi avaliada. AQTC foi realizada nos exames pré e pós-tratamento utilizando programa completamente automático. RESULTADOS: Resposta radiológica positiva foi vista em 16/29 pacientes. Os 13 pacientes sem resposta à TC apresentavam fissuras incompletas e completude média das fissuras obliquas de 72,8%, contra 88,3% no outro grupo. Os resultados mais significativos da AQTC mostraram redução do volume pulmonar (VP) total (média de 542 ml), VP tratado (700 ml) e volume de enfisema (331,4 ml) no grupo com resposta positiva, que também apresentou melhora nos testes funcionais. CONCLUSÃO: O benefício das VEB é maior em pacientes com fissuras completas e que desenvolvem atelectasia lobar. Nos pacientes sem resposta radiológica encontramos maior prevalência de fissuras incompletas e grau de incompletude das fissuras. Nossa AQTC automática detectou as alterações pós-tratamento, principalmente considerado a análise do pulmão tratado.

Keywords: Enfisema; Terapia de colapso pulmonar; Tomografia computadorizada.

The authors report the case of a 55-year-old female, hypertensive, smoker patient presenting with dysphonia, dysphagia and persistent dry cough. Laryngoscopy diagnosed left vocal cord paralysis. Computed tomography demonstrated saccular aneurysm of the inferior wall of the aortic arch, stretching the left recurrent laryngeal nerve, a finding compatible with Ortner's syndrome.

Keywords: Ortner's syndrome; Aortic arch aneurysm; Recurrent laryngeal nerve; Dysphonia; Dry cough.

OBJECTIVE: To describe the prevalence of carpal tunnel syndrome in a sample of 200 healthy hospital workers, establishing the respective epidemiological associations. MATERIALS AND METHODS: Two hundred individuals were submitted to wrist ultrasonography to measure the median nerve area. They were questioned and examined for epidemiological data, body mass index, carpal tunnel syndrome signs and symptoms, and submitted to the Boston carpal tunnel questionnaire (BCTQ) to evaluate the carpal tunnel syndrome severity. A median nerve area > 9 mm² was considered to be diagnostic of carpal tunnel syndrome. RESULTS: Carpal tunnel syndrome was diagnosed by ultrasonography in 34% of the sample. It was observed the association of carpal tunnel syndrome with age (p < 0.0001), paresthesia (p < 0.0001), Tinel's test (p < 0.0001), Phalen's test (p < 0.0001), BCTQ score (p < 0.0001), and years of formal education (p < 0.0001). Years of formal education was the only variable identified as an independent risk factor for carpal tunnel syndrome (95% CI = 1.03 to 1.24). CONCLUSION: The prevalence of carpal tunnel syndrome in a population of hospital workers was of 34%. The number of years of formal education was the only independent risk factor for carpal tunnel syndrome.

Keywords: Carpal tunnel syndrome; Ultrasonography; Median nerve area; Hand pain; Hand paresthesia.

OBJECTIVE: To assess the prevalence of isolated findings of abnormalities leading to entrapment of the lateral plantar nerve and respective branches in patients complaining of chronic heel pain, whose magnetic resonance imaging exams have showed complete selective fatty atrophy of the abductor digiti quinti muscle. MATERIALS AND METHODS: Retrospective, analytical, and cross-sectional study. The authors selected magnetic resonance imaging of hindfoot of 90 patients with grade IV abductor digiti quinti muscle atrophy according to Goutallier and Bernageau classification. Patients presenting with minor degrees of fatty muscle degeneration (below grade IV) and those who had been operated on for nerve decompression were excluded. RESULTS: A female prevalence (78.8%) was observed, and a strong correlation was found between fatty muscle atrophy and plantar fasciitis in 21.2%, and ankle varices, in 16.8% of the patients. CONCLUSION: Fatty atrophy of the abductor digiti quinti muscle is strongly associated with neuropathic alterations of the first branch of the lateral plantar nerve. The present study showed a significant association between plantar fasciitis and ankle varices with grade IV atrophy of the abductor digiti quinti muscle.

Keywords: Abductor digiti quinti muscle; Baxter; Lateral plantar nerve; Inferior calcaneal nerve; Atrophy.

OBJECTIVE: To use magnetic resonance imaging to identify vascular loops in the anterior inferior cerebellar artery and to evaluate their relationship with otologic symptoms. MATERIALS AND METHODS: We selected 33 adults with otologic complaints who underwent magnetic resonance imaging at our institution between June and November 2013. Three experienced independent observers evaluated the trajectory of the anterior inferior cerebellar artery in relation to the internal auditory meatus and graded the anterior inferior cerebellar artery vascular loops according to the Chavda classification. Kappa and chi-square tests were used. Values of p < 0.05 were considered significant. RESULTS: The interobserver agreement was moderate. Comparing ears that presented vascular loops with those that did not, we found no association with tinnitus, hearing loss, or vertigo. Similarly, we found no association between the Chavda grade and any otological symptom. CONCLUSION: Vascular loops do not appear to be associated with otoneurological manifestations.

Keywords: Arteries/anatomy & histology; Nerve compression syndromes; Magnetic resonance imaging; Tinnitus; Hearing loss; Vertigo.

Injuries of the sciatic nerve are common causes of pain and limitation in the lower limbs. Due to its particular anatomy and its long course, the sciatic nerve is often involved in diseases of the pelvis or leg. In recent years, magnetic resonance neurography has become established as an important tool for the study of peripheral nerves and can be widely applied to the study of the sciatic nerve. Therefore, detailed knowledge of its anatomy and of the most prevalent diseases affecting it is essential to maximizing the accuracy of diagnostic imaging.

Keywords: Sciatic nerve; Magnetic resonance imaging; Neuroimaging/methods; Nervous system diseases/diagnosis; Sciatic neuropathy/diagnosis.

Os nervos cranianos representam extensões das estruturas funcionais do cérebro que cruzam a cabeça e o pescoço. Eles estão ligados a diferentes estruturas cranianas e se relacionam com diversas doenças. Uma compreensão profunda de sua complexa anatomia e aparência normal de imagem permite ao examinador identificar e caracterizar com mais precisão as anormalidades. A ressonância magnética com contraste é uma importante ferramenta para avaliar essas estruturas, especialmente as sequências tridimensionais de precessão livre de estado estacionário, que proporcionam alta resolução espacial e de partes moles, apesar da fina espessura dos nervos cranianos. Na maioria dos casos, os achados de imagem são inespecíficos, e uma anamnese completa, exame físico dirigido e testes laboratoriais são necessários para estreitar o diagnóstico diferencial. Este ensaio iconográfico ilustra e discute doenças congênitas, traumáticas e vasculares dos nervos cranianos, mostrando imagens em uma abordagem fisiopatológica.

Keywords: Neuroimagem/métodos; Radiologia/métodos; Ressonância magnética/métodos; Nervos cranianos/diagnóstico por imagem.

OBJECTIVE: To evaluate qualitative and quantitative magnetic resonance imaging (MRI) criteria for injury of the common peroneal nerve (CPN) in patients with acute or subacute injuries in the posterolateral corner (PLC) of the knee, as well as to evaluate the reproducibility of MRI evaluation of CPN alterations. MATERIALS AND METHODS: This was a retrospective study of 38 consecutive patients submitted to MRI and diagnosed with acute or subacute injury to the PLC of the knee (patient group) and 38 patients with normal MRI results (control group).Two musculoskeletal radiologists (designated radiologist A and radiologist B, respectively) evaluated the images.Nerve injury was classified as neurapraxia, axonotmesis, or neurotmesis.Signal strength was measured at the CPN, the tibial nerve (TN), and a superficial vein (SV).The CPN/TN and CPN/SV signal ratios were calculated.The status of each PLC structure, including the popliteal tendon, arcuate ligament, lateral collateral ligament, and biceps tendon, was classified as normal, partially torn, or completely torn, as was that of the cruciate ligaments.For the semiquantitative analysis of interobserver agreement, the kappa statistic was calculated, whereas a receiver operating characteristic (ROC) curve was used for the quantitative analysis. RESULTS: In the patient group, radiologist A found CPN abnormalities in 15 cases (39.4%)—neurapraxia in eight and axonotmesis in seven—whereas radiologist B found CPN abnormalities in 14 (36.8%)—neurapraxia in nine and axonotmesis in five.The kappa statistic showed excellent interobserver agreement.In the control group, the CPN/TN signal ratio ranged from 0.63 to 1.1 and the CPN/SV signal ratio ranged from 0.16 to 0.41, compared with 1.30–4.02 and 0.27–1.08, respectively, in the patient group.The ROC curve analysis demonstrated that the CPN/TN signal ratio at a cutoff value of 1.39 had high (93.3%) specificity for the identification of nerve damage, compared with 81.3% for the CPN/SV signal ratio at a cutoff value of 0.41. CONCLUSION: CPN alterations are common in patients with PLC injury detected on MRI, and the level of interobserver agreement for such alterations was excellent.Calculating the CPN/TN and CPN/SV signal ratios may increase diagnostic confidence.We recommend systematic analysis of the CPN in cases of PLC injury.

Keywords: Peroneal nerve/diagnostic imaging; Knee injuries/diagnostic imaging; Knee/innervation; Magnetic resonance imaging.

In recent decades, high-resolution ultrasound (HRUS) has revolutionized the morphological and structural evaluation of peripheral nerves and muscles, revealing details of the internal structure of the neural fascicles and muscle architecture. Applications range from diagnostics to interventional procedures. The anatomy of the forearm region is complex, with several muscles and an extensive network of vessels and nerves. To guarantee the success of the evaluation by HRUS, knowledge of the normal anatomy of the region is essential. The aim of these two companion articles is to present the normal anatomy of the nerves and compartments of the forearm, as revealed by HRUS, as well as the relationships between the main vessels and nerves of the region. Part 1 aims to review the overall structure of nerves, muscles and tendons, as seen on HRUS, and that of the forearm compartments. We present a practical approach, with general guidelines and tips on how best to perform the study. Part 2 is a pictorial essay about compartment vascularization and cutaneous innervation. Knowledge of the normal anatomy of the forearm improves the technical quality of the examinations, contributing to better diagnoses, as well as improving the performance and safety of interventional procedures.

Keywords: Ultrasonography/methods; Forearm/anatomy & histology; Radial nerve/anatomy & histology; Median nerve/anatomy & histology; Ulnar nerve/anatomy & histology.

The cranial nerves, which represent extensions of the functional structures of the brain, traverse the head and neck. They are connected to various cranial structures and are associated with several diseases. An in-depth understanding of their complex anatomy and normal imaging appearance allows the examiner to identify and characterize abnormalities with greater precision. One important tool for evaluating the cranial nerves is contrast-enhanced magnetic resonance imaging, especially that employing three-dimensional steady-state free precession sequences, which provide high soft-tissue and spatial resolution, despite the slenderness of the nerves. In most cases of cranial nerve abnormalities, the imaging findings are nonspecific. Therefore, to narrow the differential diagnosis, it is necessary to take a full patient history, perform a focused physical examination, and order laboratory tests. In this pictorial essay, we review, illustrate, and discuss, from a pathophysiological perspective, infectious, neoplastic, and demyelinating disorders, as well as other inflammatory disorders, affecting the cranial nerves, the aim being to provide a practical, tangible reference for radiologists to use in daily practice.

Keywords: Cranial nerves/physiopathology; Cranial nerve diseases/diagnostic imaging; Demyelinating diseases/diagnostic imaging; Magnetic resonance imaging/methods.

OBJETIVO: Avaliar os padrões tomográficos relacionados aos agentes etiológicos da pneumonia em pacientes durante o primeiro ano após transplante renal. MATERIAIS E MÉTODOS: Foram analisados dados de prontuários de 956 pacientes submetidos a transplante renal, no período de 2013 a 2018, em um centro transplantador renal do nordeste do Brasil. Nos pacientes que desenvolveram pneumonia, os agentes etiológicos foram classificados em bactérias piogênicas, micobactérias, fungos, vírus e pneumonia polimicrobiana, enquanto os padrões tomográficos foram classificados em consolidação, broncopneumonia, pneumonia intersticial e nódulos e massas. Para verificar associação estatística entre micro-organismos e padrões tomográficos, foi utilizado o teste exato de Fisher, com p < 0,001. RESULTADOS: Foram encontrados 101 casos de pneumonia, dos quais 60 (59,4%) tiveram agente etiológico identificado, sendo as bactérias piogênicas as mais frequentes, detectadas em 22 (36,7%) dos casos. Entre os pacientes com agente causal identificado, o padrão tomográfico predominante foi o de nódulos e massas, identificado em 25 (41,7%) casos. Foi observada associação entre bactérias piogênicas e o padrão de consolidação, fungos com nódulos e massas, bem como entre agentes virais e padrão intersticial. CONCLUSÃO: Foi demonstrada associação estatística entre micro-organismos causadores de pneumonia e padrões tomográficos, informação que pode contribuir para o planejamento da terapia de pacientes transplantados renais.

Keywords: Pneumonia; Transplante de rim; Tomografia computadorizada.