Diffusion-weighted magnetic resonance (DW-MR) neurography of the lumbar plexus in the preoperative planning of lateral access lumbar surgery.

PURPOSE: Magnetic resonance (MR) neurography has been used to evaluate entire nerves and nerve bundles by providing better contrast between the nerves and the surrounding tissues. The purpose of the study was to validate diffusion-weighted MR (DW-MR) neurography in visualizing the lumbar plexus during preoperative planning of lateral transpsoas surgery. METHODS: Ninety-four (188 lumbar plexuses) spine patients underwent a DW-MR examination of the lumbar plexus in relation to the L3-4 and L4-5 disc spaces and superior third of the L5 vertebral body. Images were reconstructed in the axial plane using high-resolution Maximum Intensity projection (MIP) overlay templates at the disc space and L3-4 and L4-5 interspaces. 10 and 22 mm MIP templates were chosen to mimic the working zone of standard lateral access retractors. The positions of the L4 nerve root and femoral nerve were analyzed relative to the L4-5 disc in axial and sagittal planes. Third-party radiologists and a senior spine surgeon performed the evaluations, with inter- and intraobserver testing performed. RESULTS: In all subjects, the plexus was successfully mapped. At L3-4, in all but one case, the components of the plexus (except the genitofemoral nerve) were located in the most posterior quadrant (zone IV). The L3 and L4 roots coalesced into the femoral nerve below the L4-5 disc space in all subjects. Side-to-side variation was noted, with the plexus occurring in zone IV in 86.2 % right and only 78.7 % of left sides. At the superior third of L5, the plexus was found in zone III in 27.7 % of right and 36.2 % of left sides; and in zone II in 4.3 % right and 2.1 % left sides. Significant inter- and intraobserver agreement was found. CONCLUSIONS: By providing the surgeon with a preoperative roadmap of the lumbar plexus, DW-MR may improve the safety profile of lateral access procedures.

Anatomy of the great vessels by magnetic resonance in anterior lumbar interbody fusion / Anatomia dos grandes vasos por ressonância magnética na fusão intersomática lombar anterior / Anatomía de los grandes vasos por resonancia magnética en fusión intersomática lumbar anterior

ABSTRACT: Objective: To perform an analysis of the anatomy of the great vessels relevant to the access for anterior lumbar interbody fusion (ALIF), determining the level of their bifurcation, the distance between the iliac vessels at L5-S1, the morphological configuration of the left iliac vein and the presence of fatty tissue between the vessel and the disc. Methods: Two hundred magnetic resonance imaging (MRI) scans of the lumbar spine of patients (18-80 years old) were evaluated using axial, coronal, and sagittal cuts at levels L1-S1 in T2 weighting. The interiliac distance was defined as the measurement between the left iliac vein and the right iliac artery. The presence of fatty tissue was defined as the identification of space between the vessel and the disc. Vessel morphology was divided into oval and flat. Results: The population's average age was 49.6 years, with 52% being female. The average interiliac distance at L5-S1 was 27.48mm. The bifurcation of the aorta artery was identified at the level of L4 in 56.3%, as well as the confluence of the iliac veins (37.2%). The left iliac vein was identified as oval in 69% of patients and flat in 31% of patients. Fat tissue was evidenced in 60.5% of the exams. Conclusion: As a routine preoperative examination and surgical planning, lumbar MRI is fundamental in investigating the anatomy regarding anterior approach surgeries, allowing an effective assessment of the relationships between the great vessels and the lumbar spine. Level of Evidence IV; Retrospective Investigation.

RESUMO: Objetivo: Realizar uma análise da anatomia dos grandes vasos relevantes ao acesso para fusão intersomática lombar anterior (ALIF), determinando o nível de sua bifurcação, a distância entre os vasos ilíacos em L5-S1, a configuração morfológica da veia ilíaca esquerda e a presença de tecido gorduroso entre o vaso e o disco. Métodos: duzentos exames de ressonância magnética (RM) da coluna lombar de pacientes (18-80 anos) foram avaliados, utilizando cortes axiais, coronais e sagitais nos níveis L1-S1, na ponderação T2. A distância interilíaca foi definida como a medida entre a veia ilíaca esquerda e artéria ilíaca direita. A presença de tecido gorduroso foi definida como identificação de espaço entre o vaso e o disco. A morfologia do vaso foi dividida em oval e plana. Resultados: A idade média da população foi de 49,6 anos, sendo 52% mulheres. A distância média interilíacas em L5-S1 foi 27,48 mm. A bifurcação da artéria aorta foi identificada ao nível de L4 em 56,3%. A confluência das veias ilíacas também foi mais frequente ao nível de L4, representando 37,2%. A veia ilíaca esquerda foi identificada com o formato oval em 69% e plana em 31% dos pacientes. Tecido gorduroso foi evidenciado em 60,5% dos exames. Conclusão: Como rotina no exame pré-operatório e no planejamento cirúrgico, a RM lombar tem fundamental importância na investigação da anatomia visando cirurgias de abordagem anterior, pois permite uma avaliação eficaz das relações entre os grandes vasos e a coluna lombar. Nível de Evidência IV; Investigação Retrospectiva.

RESUMEN: Objetivo: Realizar un análisis de la anatomía de los grandes vasos relevantes para el acceso en artrodesis intersomática lumbar anterior (ALIF), determinando el nivel de su bifurcación, la distancia entre los vasos ilíacos en L5-S1, la configuración morfológica de la vena ilíaca izquierda y la presencia de tejido graso entre el vaso y el disco. Métodos: Se evaluaron 200 imágenes de resonancia magnética (RM) de la columna lumbar de pacientes (18-80 años) mediante cortes axiales, coronales y sagitales en los niveles L1-S1, en ponderación T2. La distancia interilíaca se definió como la medida entre la vena ilíaca izquierda y la arteria ilíaca derecha. La presencia de tejido graso se definió como la identificación de espacio entre el vaso y el disco. La morfología de los vasos se dividió en ovalados y planos. Resultados: La edad media de la población fue de 49,6 años, de los cuales 52% eran mujeres. La distancia interilíaca media en L5-S1 fue de 27,48 mm. La bifurcación de la arteria aorta se identificó a nivel de L4 en 56,3%, así como la confluencia de las venas ilíacas (37,2%). La vena ilíaca izquierda se identificó como ovalada en 69% y plana en 31%. Se evidenció tejido graso en 60,5% de los exámenes. Conclusión: Como rutina en examen preoperatorio, la RM lumbar es fundamental en la investigación de anatomía de cirugías de abordaje anterior, permitiendo una evaluación eficaz de las relaciones entre los grandes vasos y la columna lumbar. Nivel de Evidencia IV; Investigación Retrospectiva.

Morphometric analysis of the surgical corridor in the pre-psoas approach: an mri study in the brazilian population / Análise morfométrica do corredor cirúrgico no acesso pré-psoas: um estudo por ressonância magnética da coluna lombar na população brasileira / Análisis morfométrica del corredor quirúrgico en el acceso prepsoas: un estudio de resonancia magnética de la columna lumbar en la población brasileña

ABSTRACT Objective: This study aims to perform a morphometric analysis and explore the characteristics of the surgical corridor of the anterior to psoas approach in the Brazilian population through magnetic resonance imaging (MRI). Methods: Two hundred spinal MRI scans of patients aged between 18 and 80 years were evaluated using axial cuts at L2-L5 levels and a sagittal cut, T2 weighted. The relationship between the left psoas muscle and the abdominal aorta or the left common iliac artery was analyzed. The anterior to psoas corridor was defined as the shortest distance between the posterolateral aspect of the aorta or inferior vena cava or the nearest iliac vessel and the anteromedial aspect of the ipsilateral psoas muscle. Results: 104 females and 96 males with a mean age of 49,68±2.04 (range 18-80) years. The mean anterior to psoas distance at the L2-L3 level was 14,17±0.75mm; at the L3-L4 level was 12,08±0.77m,m and at the L4-L5 level was 9,12±0.77mm. The surgical corridors at all levels were larger in the older population. Conclusion: In most Brazilian patients, the anterior to psoas approach can be a good alternative for lumbar intervertebral fusions. As a routine in preoperative examination and surgical planning, lumbar MRI is fundamental in preoperative evaluation for anterior to psoas approach surgery. Level of Evidence IV; Descriptive study.

Resumo: Objetivo: O objetivo deste estudo é realizar uma análise morfométrica e explorar as características do corredor cirúrgico da via anterior ao psoas na população brasileira, através de exames de ressonância magnética. Métodos: Duzentos exames de ressonância magnética da coluna lombar de pacientes entre 18 e 80 anos foram avaliados, utilizando cortes axiais nos níveis L2-L5 e um corte sagital na ponderação T2. A relação entre o músculo psoas esquerdo e a aorta abdominal ou a artéria ilíaca comum esquerda foi analisada. O corredor anterior ao psoas foi definido como a menor distância entre a face posterolateral da aorta ou veia cava inferior ou o vaso ilíaco mais próximo e a face anteromedial do músculo psoas ipsilateral. Resultados: A população estudada foi de 104 mulheres e 96 homens com idade média de 49,68±2,04 (18-80) anos. A média da distância anterior ao psoas no nível L2-L3 foi de 14,17 ± 0,75mm; no nível L3-L4 foi de 12,08 ± 0,77mm e no nível L4-L5 foi de 9,12 ± 0,77mm. Os corredores cirúrgicos em todos os níveis foram considerados maiores na população idosa. Conclusão: A abordagem anterior ao psoas pode ser uma boa alternativa para a fusão intervertebral lombar na maioria dos pacientes brasileiros. Como rotina no exame pré-operatório e no planejamento cirúrgico, a ressonância magnética lombar tem fundamental importância na avaliação pré-operatória de cirurgias de abordagem anterior ao psoas. Nível de Evidencia IV; Estudo descritivo.

Resumen: Objetivo: El objetivo de estudio es realizar un análisis morfométrico y explorar las características del corredor quirúrgico de la vía anterior al psoas en la población brasileña, a través de resonancias magnéticas (RM). Métodos: Se evaluaron 200 RM de la columna lumbar de pacientes entre 18 y 80 años, utilizando cortes axiales a niveles L2-L5 y un corte sagital, con ponderación T2. Se analizó la relación entre el músculo psoas izquierdo y la aorta abdominal o la arteria ilíaca común izquierda. El corredor anterior al psoas se definió como la distancia más corta entre la cara posterolateral de la aorta o la vena cava inferior o el vaso ilíaco más cercano y la cara anteromedial del músculo psoas ipsilateral. Resultados: La población estudiada estuvo constituida por 104 mujeres y 96 hombres con una edad media de 49,68±2,04 (18-80) años. La distancia media anterior al psoas en nivel L2-L3 fue de 14,17 ± 0,75 mm; en el nivel L3-L4 fue de 12,08 ± 0,77 mm y en el nivel L4-L5 fue de 9,12 ± 0,77 mm. Los corredores quirúrgicos en todos niveles se consideraron más grandes en la población anciana. Conclusión: El abordaje del psoas anterior puede ser una alternativa para la fusión intervertebral lumbar en la mayoría de los pacientes brasileños. Como rutina en examen preoperatorio, la resonancia magnética lumbar es importante en la evaluación preoperatoria de cirugías con abordaje anterior del psoas. Nivel de Evidencia IV; Estudio descriptivo.

Magnetic resonance imaging and ultrasound in hepatosplenic schistosomiasis mansoni.

We report the findings of abdominal ultrasound and magnetic resonance imaging observed in a patient with advanced schistosomiasis mansoni. A 25-year-old man with hepatosplenic schistosomiasis and variceal bleeding confirmed by upper endoscopy was submitted to abdominal ultrasound and magnetic resonance imaging. During surgery for portal hypertension, a liver biopsy was taken and the diagnosis of Symmers' fibrosis was confirmed. magnetic resonance imaging scans gave more precise information about the gallbladder, periportal thickening and abdominal venous system than did the ultrasound.

[Schistosomal myeloradiculopathy]. / Mielorradiculopatia esquistossomótica.

Schistosomal myeloradiculopathy is the most severe and disabling ectopic form of schistosomiasis mansoni. Its prevalence in endemic areas has been underestimated. The diagnosis relies on the presence of low thoracic/upper lumbar neurological symptoms, demonstration of the Schistosoma mansoni infection by microscopic or serologic techniques, and exclusion of other causes of transverse myelitis. When treatment with antischistosomal drugs and corticosteroids is started early, the clinical response is surprisingly good and those left untreated do not improve and frequently die. There is no consensus about doses and duration of treatment, but a recent study suggests that when steroids are given for at least 6 months clinical improvement is enhanced. As the diagnosis of SMR is presumptive and treatment is essentially clinical, physicians should be aware of the disease and more research is needed to increase the accuracy of the diagnostic methods and, hence, to avoid routine laminectomy. With the advent of magnetic resonance imaging of the spinal cord the diagnosis of this ectopic form of the disease was facilitated. In accordance, the number of cases of schistosomal myelopathy reported is increasing rapidly.

Ultrasound and magnetic resonance imaging findings in Schistosomiasis mansoni: expanded gallbladder fossa and fatty hilum signs.

INTRODUCTION: There is no study relating magnetic resonance imaging (MRI) to ultrasound (US) findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years) from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma). RESULTS: Forty-seven (87%) of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%), MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1%) of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI) is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.

Study of arterial pattern of 200 renal pedicle through angiotomography.

OBJECTIVE: To investigate the prevalence and distribution of renal arteries and their branches in vivo, correlating the particularities found in them with sex and laterality. METHODS: Two hundred renal pedicles were studied by CT angiography and its arteries analyzed according to number, position of origin, size, length and trajectory in relation to renal segments. Its frequency and laterality were surveyed regarding gender and age. RESULTS: There were multiple arteries in 61.5% of the pedicles (56% in the right and 67% in the left), occurring in 65% of men and 58% of women. The aortic origin to the multiple arteries was more frequent on the right and, more often, the renal arteries originated between vertebrae L1 and L2 as pre-hilar division of the main artery. The average length of the main artery was higher in right kidneys with a single artery. There was no difference between the diameters of the main renal arteries. CONCLUSION: There is a higher prevalence of multiple renal arteries than the one described in the literature, with no difference for gender or laterality. The renal arteries originated more frequently between vertebrae L1 and L2, with divisions of the pre-hilar route and main artery to the hilum of the kidney. The average length of the main artery is greater on the right and in kidneys with single artery. There was no difference in diameter between the main renal artery between kidneys with single and multiple arteries.

Imaging techniques in the evaluation of morbidity in schistosomiasis mansoni.

Over the last 20 years a great advance has been observed in many aspects of medicine, and the advent of novel imaging techniques is certainly amongst the most important. In schistosomiasis these new methods caused a revolution in the definition of the clinical forms of the disease and in the evaluation of its complications, such as, liver fibrosis, pulmonary hypertension and neuroschistosomiasis, as never before. Herein we present an overview of the image methods used to diagnose schistosomiasis mansoni nowadays.

Ultrasound and magnetic resonance imaging findings in Schistosomiasis mansoni: expanded gallbladder fossa and fatty hilum signs / Achados da ultrassonografia e da ressonância magnética na esquistossomose mansônica: sinais da expansão da fossa da vesícula e do hilo gorduroso

INTRODUCTION: There is no study relating magnetic resonance imaging (MRI) to ultrasound (US) findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years) from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma). RESULTS: Forty-seven (87%) of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%), MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1%) of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI) is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.

INTRODUÇÃO: Não existem estudos que correlacionam os achados da ressonância magnética (RM) aos da ultrassonografia (US) em pacientes com esquistossomose mansônica. O objetivodeste estudo foi descrever os achados da imagem por RM em pacientes com doença hepática esquistossomótica identificada por US. MÉTODOS: Selecionaram-se 54 pacientes com idade média de 41,6±13,5 anos, provenientes de área endêmica para a esquistossomose mansônica. Todos apresentavam US indicativa de fibrose hepática esquistossomótica, e foram avaliados com imagens por RM, realizadas com uma unidade magnética supercondutora de 1,5-T(Sigma). RESULTADOS: Quarenta e sete (87%) entre 54 pacientes com sinais ultrassonográficosde fibrose periportal esquistossomótica tiveram este diagnóstico confirmado pela RM. Nos sete(13%) casos discordantes, a RM revelou tecido adiposo preenchendo o espaço periportal hilaronde a US indicava espessamento isolado da parede da veia porta em seu ponto de entrada no fígado. Este achado foi nomeado sinal do hilo gorduroso. Um dos 47 pacientes com evidência de fibrose periportal RM era colecistectomizado. Trinta e quatro (76,1%) dos 46 pacientes restantes apresentavam expansão da fossa da vesícula, que se encontrava preenchida portecido adiposo. Nos outros sete, a RM revelou sinais de fibrose pericolecística. CONCLUSÕES: Os espessamentos ecogênicos central da parede da veia porta, e da parede da vesícula biliar, até o momento, atribuídos à fibrose, foram frequentemente identificados como tecido adiposopela RM. Entretanto, o espessamento da parede da vesícula identificado pela US (expansão da fossa da vesícula na RM) é provavelmente secundário a alterações morfológicas hepáticas na esquistossomose, e representa comprometimento grave do fígado.

Estudo do padrão arterial de 200 pedículos renais por meio de angiotomografias / Study of arterial pattern of 200 renal pedicle through angiotomography

OBJETIVO: Verificar a prevalência e a distribuição das artérias renais e de seus ramos in vivo, relacionando as particularidades encontradas nas artérias renais com o sexo e sua lateralidade. MÉTODO: Duzentos pedículos renais foram estudados por meio de angiotomografias e suas artérias analisadas de acordo com número, posição de origem, calibre, comprimento e trajeto em relação aos segmentos renais. Sua frequência e lateralidade foram pesquisadas quanto ao sexo e idade. RESULTADOS: Foram observadas múltiplas artérias em 61,5 por cento dos pedículos (56 por cento à direita e 67 por cento à esquerda), ocorrendo em 65 por cento dos homens e 58 por cento das mulheres. A origem aórtica para as múltiplas artérias foi mais frequente à direita e, com maior frequência, as artérias renais se originaram entre as vértebras L1 e L2 como divisões pré-hilares da artéria principal. O comprimento médio da artéria principal foi maior em rins direitos com artéria única. Não houve diferença entre o diâmetro da artéria renal principal. CONCLUSÃO: Existe maior prevalência das múltiplas artérias renais do que aquela descrita na literatura, sem diferença entre os sexos ou lateralidade. As artérias renais originaram-se com maior frequência entre as vértebras L1 e L2, como divisões pré-hilares da artéria principal e com trajeto ao hilo do rim. O comprimento médio da artéria principal é maior à direita e nos rins com artéria única. Não houve diferença no diâmetro da artéria renal principal entre rins com artérias únicas e múltiplas.

OBJECTIVE: To investigate the prevalence and distribution of renal arteries and their branches in vivo, correlating the particularities found in them with sex and laterality. METHODS: Two hundred renal pedicles were studied by CT angiography and its arteries analyzed according to number, position of origin, size, length and trajectory in relation to renal segments. Its frequency and laterality were surveyed regarding gender and age. RESULTS: There were multiple arteries in 61.5 percent of the pedicles (56 percent in the right and 67 percent in the left), occurring in 65 percent of men and 58 percent of women. The aortic origin to the multiple arteries was more frequent on the right and, more often, the renal arteries originated between vertebrae L1 and L2 as pre-hilar division of the main artery. The average length of the main artery was higher in right kidneys with a single artery. There was no difference between the diameters of the main renal arteries. CONCLUSION: There is a higher prevalence of multiple renal arteries than the one described in the literature, with no difference for gender or laterality. The renal arteries originated more frequently between vertebrae L1 and L2, with divisions of the pre-hilar route and main artery to the hilum of the kidney. The average length of the main artery is greater on the right and in kidneys with single artery. There was no difference in diameter between the main renal artery between kidneys with single and multiple arteries.

Magnetic resonance imaging and ultrasound in hepatosplenic schistosomiasis mansoni

Relatamos os achados ultrassonográficos e à ressonância magnética intra-abdominais observados em um paciente com esquistossomose mansoni grave. Um homem de 25 anos de idade com esquistossomose hepatoesplênica e sangramento digestivo de varizes esofagianas, com diagnóstico confirmado pela endoscopia, foi submetido à ultrasonografia abdominal e ressonância magnética. Durante a cirurgia de hipertensão porta, um fragmento de fígado foi obtido e o exame histológico confirmou o diagnóstico de fibrose de Symmers. A ressonância magnética forneceu informações mais precisas sobre a vesícula biliar, espessamento periportal e sistema venoso abdominal do que a ultrassonografia.