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Dive into the research topics where Luis Ronan Marquez Ferreira de Souza is active.

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Featured researches published by Luis Ronan Marquez Ferreira de Souza.


Journal of Ultrasound in Medicine | 2005

Flow Pattern and Vascular Resistive Index as Predictors of Malignancy Risk in Thyroid Follicular Neoplasms

Harley De Nicola; Jacob Szejnfeld; Ângela Flávia Logullo; Ângela Maria Borri Wolosker; Luis Ronan Marquez Ferreira de Souza; Valcir Chiferi

The purpose of this study was to evaluate whether flow pattern and resistive index (RI) are useful parameters for distinguishing benign from malignant thyroid follicular neoplasms (FNs).


Sao Paulo Medical Journal | 2007

Comparison between ultrasound and noncontrast helical computed tomography for identification of acute ureterolithiasis in a teaching hospital setting.

Luis Ronan Marquez Ferreira de Souza; Suzan Menasce Goldman; Salomao Faintuch; Juliano Faria; Daniel Bekhor; Dario Ariel Tiferes; Valdemar Ortiz; Peter Choyke; Jacob Szejnfeld

CONTEXT AND OBJECTIVE Recent studies have shown noncontrast computed tomography (NCT) to be more effective than ultrasound (US) for imaging acute ureterolithiasis. However, to our knowledge, there are few studies directly comparing these techniques in an emergency teaching hospital setting. The objectives of this study were to compare the diagnostic accuracy of US and NCT performed by senior radiology residents for diagnosing acute ureterolithiasis; and to assess interobserver agreement on tomography interpretations by residents and experienced abdominal radiologists. DESIGN AND SETTING Prospective study of 52 consecutive patients, who underwent both US and NCT within an interval of eight hours, at Hospital São Paulo. METHODS US scans were performed by senior residents and read by experienced radiologists. NCT scan images were read by senior residents, and subsequently by three abdominal radiologists. The interobserver variability was assessed using the kappa statistic. RESULTS Ureteral calculi were found in 40 out of 52 patients (77%). US presented sensitivity of 22% and specificity of 100%. When collecting system dilatation was associated, US demonstrated 73% sensitivity, 82% specificity. The interobserver agreement in NCT analysis was very high with regard to identification of calculi, collecting system dilatation and stranding of perinephric fat. CONCLUSIONS US has limited value for identifying ureteral calculi in comparison with NCT, even when collecting system dilatation is present. Residents and abdominal radiologists demonstrated excellent agreement rates for ureteral calculi, identification of collecting system dilatation and stranding of perinephric fat on NCT.


Radiologia Brasileira | 2012

Avaliação por imagem das lesões císticas congênitas das vias biliares

Luis Ronan Marquez Ferreira de Souza; Flávio Batista Rodrigues; Lucas Vieira Tostes; Graziella Borges Barreto; Mateus Saldanha Cardoso

Based on the classification of congenital choledochal cysts, images of different cyst types were selected to compose a pictorial essay about this disease, which is not frequently observed in the medical practice, but is included in the differential diagnosis of most common lesions of the biliary tract. Choledochal cysts present nonspecific symptoms and low prevalence. The correct diagnosis based on imaging findings is mandatory to avoid complications, and to aid in the approach and definite treatment.


Radiologia Brasileira | 2007

Aspectos ultra-sonográficos das alterações não-neoplásicas do testículo

Ricardo Jorge Vital; Leandro Accardo de Mattos; Luis Ronan Marquez Ferreira de Souza; Sizenildo da Silva Figueirêdo; Jacob Szejnfeld

Pathological processes of the testis are very frequently found, and include non-tumoral and tumoral lesions. Ultra-sonography performed with a high-frequency transducer has become the imaging modality of choice for examination of these organs. This method is of help to improve intratesticular lesions characterization, and in many instances the findings suggest a more specific diagnosis, especially in the presence of similar clinical manifestations such as pain, swelling and local increase in volume. Color Doppler is an invaluable tool for demonstrating anomalous patterns of testicular perfusion and aids in the diagnosis of acute clinical conditions. In the present iconographic essay, the authors summarize the most frequent clinical, pathological findings as well as the main diagnostic features of benign intratesticular lesions such as microlithiasis, simple cysts, spermatocele, varicocele, tubular ectasia of the rete testis, orchitis, hematomas and more rare conditions. Familiarity with clinical and sonographic features is essential for the correct diagnosis and starting of the most effective therapy, as necessary.


Radiologia Brasileira | 2014

Scrotal collections: pictorial essay correlating sonographic with magnetic resonance imaging findings

Daniel de Almeida Queiroz Prata Resende; Luis Ronan Marquez Ferreira de Souza; Isabela de Oliveira Monteiro; Marcel Henrique de Souza Caldas

The present study is aimed at describing scrotal collections observed at ultrasonography and magnetic resonance imaging. The authors describe the main features of hydrocele, hematocele and pyocele, as well as the most common causes, clinical manifestations and associated diseases, with a brief review of the embryology and anatomy of the scrotum. Collections are frequently found in the evaluation of the scrotum, which is often performed on an emergency basis, and in most cases can be differentiated by means of imaging studies. With the consolidation of magnetic resonance imaging as the method of choice complementary with ultrasonography, the authors also describe magnetic resonance imaging findings of scrotal collections as well as the situations where such method is indicated.


Radiologia Brasileira | 2014

Laryngeal schwannoma: a case report with emphasis on sonographic findings

Luis Ronan Marquez Ferreira de Souza; Harley De Nicola; Rosiane Yamasaki; José Eduardo de Sá Pedroso; Osíris de Oliveira Camponês do Brasil; Helio K. Yamashita

Schwannomas are benign nerve sheath tumors composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral, cranial and autonomic nerves. Twenty-five to forty-five percent of all schwannomas occur in the head and neck region, but location of such tumors in the larynx is rarely observed. The present report is aimed at describing a clinical case of laryngeal schwannoma, with emphasis on sonographic findings.


Journal of Ultrasound in Medicine | 2009

Angiomyofibroblastoma-Like Tumor of the Inguinal Canal

Luis Ronan Marquez Ferreira de Souza; Eduardo Carvalho Filho; Wendel Pereira Braga; Paulo Tadeu Cortes Martins; Harley De Nicola

ngiomyofibroblastoma (AMF) is described as a superficial tumor of the vulva that occurs almost exclusively in the vulvovaginal region. It may also occur on rare occasions in the inguinoscrotal region. The first case was described in 1998, 1 in the form of a mesenchymal tumor of the male genital tract. It was histomorphologically similar to female AMF and to spindle cell lipoma. We report a case of AMF that was confirmed pathologically, along with a review of the cases available in the literature.


Radiologia Brasileira | 2011

Espessamento parietal da vesícula biliar no exame ultrassonográfico: como interpretar?

Aldo Benjamim Rodrigues Barbosa; Luis Ronan Marquez Ferreira de Souza; Rogério Silva Pereira; Giuseppe D'Ippolito

The present review was aimed at providing help for correct interpretation of gallbladder wall thickening and differential diagnosis at ultrasonography. Gallbladder wall thickening is a frequent sonographic finding and has been subject of great interest for being considered as a hallmark feature of acute cholecystitis, despite the fact that such a finding is observed in a number of other medical conditions. An appropriate characterization and interpretation of this finding is of great importance, considering that the correct diagnosis has a direct impact on the treatment that in some cases includes surgery. In the present article, the authors describe a set of sonographic signs that, in association with clinical and laboratory findings can reduce the number of diagnostic hypotheses allowing a more accurate establishment of the cause for gallbladder wall thickening through a rational data evaluation.


Radiologia Brasileira | 2017

What radiologists should know about tomographic evaluation of acute diverticulitis of the colon

Aline de Araújo Naves; Giuseppe D'Ippolito; Luis Ronan Marquez Ferreira de Souza; Sílvia Portela Borges; Glênio Moraes Fernandes

Acute diverticulitis of the colon is a common indication for computed tomography, and its diagnosis and complications are essential to determining the proper treatment and establishing the prognosis. The adaptation of the surgical classification for computed tomography has allowed the extent of intestinal inflammation to be established, the computed tomography findings correlating with the indication for treatment. In addition, computed tomography has proven able to distinguish among the main differential diagnoses of diverticulitis. This pictorial essay aims to present the computed tomography technique, main radiological signs, major complications, and differential diagnoses, as well as to review the classification of acute diverticulitis.


Radiologia Brasileira | 2015

Sonographic evaluation of children with congenital hypothyroidism

Anelise de Almeida Sedassari; Luis Ronan Marquez Ferreira de Souza; Nathalie de Almeida Sedassari; Maria de Fátima Borges; Heloísa Marcelina da Cunha Palhares; Genésio Borges de Andrade Neto

Objective To establish benchmarks and study some sonographic characteristics of the thyroid gland in a group of euthyroid children aged up to 5 years as compared with age-matched children with congenital hypothyroidism. Materials and Methods Thirty-six children (17 female and 19 male) aged between 2 months and 5 years were divided into two groups – 23 euthyroid children and 13 children with congenital hypothyroidism – and were called to undergo ultrasonography. Results In the group of euthyroid children (n = 23), mean total volume of the thyroid gland was 1.12 mL (minimum, 0.39 mL; maximum, 2.72 mL); a homogeneous gland was found in 17 children (73.91%) and 6 children (26.08%) had a heterogeneous gland. In the group of children with congenital hypothyroidism (n = 13), mean total volume of the thyroid gland was 2.73 mL (minimum, 0.20 mL; maximum, 11.00 mL). As regards thyroid location, 3 patients (23.07%) had ectopic thyroid, and 10 (69.23%) had topic thyroid, and out of the latter, 5 had a homogeneous gland (50%) and 5, a heterogeneous gland (50%). In the group with congenital hypothyroidism, 6 (46.15%) children had etiological diagnosis of dyshormoniogenesis, 3 (23.07%), of ectopic thyroid, and 4 (30.76%), of thyroid hypoplasia. Conclusion Thyroid ultrasonography is a noninvasive imaging method, widely available, easy to perform and for these reasons could, and should, be performed at any time, including at birth, with no preparation or treatment discontinuation, to aid in the early etiological definition of congenital hypothyroidism.

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Dive into the Luis Ronan Marquez Ferreira de Souza's collaboration.

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Jacob Szejnfeld

Federal University of São Paulo

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Harley De Nicola

Federal University of São Paulo

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Suzan Menasce Goldman

Federal University of São Paulo

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Giuseppe D'Ippolito

Federal University of São Paulo

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Daniel Bekhor

Federal University of São Paulo

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Dario Ariel Tiferes

Federal University of São Paulo

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Leandro Accardo de Mattos

Federal University of São Paulo

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Ricardo Jorge Vital

Federal University of São Paulo

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Salomao Faintuch

Beth Israel Deaconess Medical Center

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