Publications by authors named "Rubens Chojniak"

Objective: To assess the diagnostic success rate and complications of computed tomography (CT)-guided percutaneous biopsy in pulmonary nodules < 10 mm in diameter.

Materials And Methods: This was a retrospective, single-center study involving the review of medical records, images, and chest CT reports related to 115 patients who underwent percutaneous CT-guided biopsy of < 10 mm pulmonary nodules between July 2015 and January 2019.

Results: Nodule diameter on the longest axis ranged from 4 mm to 9 mm, with a mean size of 7.

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Collisions lesions are rare neoplasms where two histologically distinct tumors coexist in the same organ or anatomical site. Vertebral hemangiomas (VHs) are the most common lesions involving the vertebral bodies and imaging findings of typical and atypical hemangiomas, variant forms of hemangioma such as aggressive hemangiomas are well known, but collision lesions involving VHs are extremely rare. This article presents a case report of a 73-year-old male patient diagnosed with clear cell renal cancer in a rare presentation of a bone metastasis coinciding with the same anatomical position as a VH (collision lesion).

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Objective: To evaluate the results obtained with an artificial intelligence-based software for predicting the risk of malignancy in breast masses from ultrasound images.

Materials And Methods: This was a retrospective, single-center study evaluating 555 breast masses submitted to percutaneous biopsy at a cancer referral center. Ultrasonographic findings were classified in accordance with the BI-RADS lexicon.

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Objective: The purpose of our study was to evaluate the transmission of information from radiologists to physicians, focusing on the level of certainty and the use of imaging descriptors from the tumor-node-metastasis (TNM) staging system.

Materials And Methods: Radiologists (n = 56) and referring physicians (n = 50) participated in this questionnaire-based, singlecenter study, conducted between March 20, 2020, and January 21, 2021. Participants were presented with terms commonly used by the radiologists at the institution and were asked to order them hierarchically in terms of the level of certainty they communicate regarding a diagnosis, using a scale ranging from 1 (most contrary to) to 10 (most favoring).

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Objectives: Contrast-enhanced breast imaging has gained increasing importance in the diagnosis and management of breast cancer. The aim of this study was to assess breast cancer enhancement after contrast administration on prone multidetector computed tomography (MDCT).

Materials And Methods: This retrospective, unicentric, institutional review board-approved study included patients with newly diagnosed breast cancer who were submitted to contrast-enhanced MDCT in prone position, with image acquisition before and after nonionic iodinated contrast administration.

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Invasive procedures guided by ultrasound (US) are part of routine medical diagnostic investigation. The lack of knowledge surrounding the technical aspects of such procedures can lead patients to seek complementary information on the Internet, which may in turn trigger anxiety. However, the intersection between the fields of Radiology and Psychology is poorly studied.

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Objetivo: Identificar o perfil de utilização dos recursos didáticos pelos médicos radiologistas e residentes em radiologia e diagnóstico por imagem brasileiros.

Materiais E MÉtodos: Estudo observacional, transversal e descritivo, realizado por meio de questionário eletrônico contendo perguntas referentes ao perfil do médico, formação, local de atuação, perfil de acesso a recursos educacionais e tipos de recursos mais utilizados.

Resultados: Responderam ao questionário 265 médicos com idade média de 38,2 anos, sendo a maioria radiologistas formados (170; 64,2%), do sexo masculino (166; 62,6%), trabalhando em instituições privadas (174; 65,7%), sem vínculo acadêmico (167; 63,0%), atuando principalmente nas áreas de ultrassonografia (212; 80,0%) e tomografia computadorizada (206; 77,7%).

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Objective: To assess the technique, efficacy, and safety of computed tomography (CT)-guided percutaneous biopsies of head and neck masses.

Materials And Methods: This was a retrospective, single-center study of CT-guided percutaneous core-needle biopsies of head and neck masses. For the analysis of diagnostic accuracy, biopsy results were compared with the final diagnosis, which was determined by histological examination and clinical follow-up.

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Objective: To investigate the impact of response evaluation after neoadjuvant chemotherapy (NAC) in breast cancer patients, assessed by both magnetic resonance imaging (MRI) and pathology, on disease-free survival (DFS).

Methods: This single-center, retrospective cohort study included consecutive breast cancer patients who underwent NAC and preoperative breast MRI. Resolution of invasive carcinoma in the breast and axilla was defined as complete pathological response (pCR).

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Objective: To evaluate the accuracy of chest computed tomography (CT) in patients with suspected severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) infection at a cancer center.

Materials And Methods: This retrospective single-center study selected 91 patients who had chest CT and real-time polymerase chain reaction (RT-PCR) test collected at the same day. CT results were classified in negative, typical, indeterminate or atypical findings.

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Background: The purpose of this study was to determine whether whole-body MRI (WBMRI) with diffusion-weighted sequences, which is free of ionizing radiation, can perform as well as traditional methods when used alone for staging or follow-up of pediatric cancer patients.

Methods: After obtaining approval from our institutional research ethics committee and appropriate informed consent, we performed 34 examinations in 32 pediatric patients. The examinations were anonymized and analyzed by two radiologists with at least 10 years' experience.

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To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the assessment of therapeutic response in patients with choroidal melanoma treated with brachytherapy. We performed a prospective, unicentric study which included patients with choroidal melanoma and indication for brachytherapy. Three DW-MRI examinations were proposed for each patient, one before and two after treatment.

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Objective: To determine the average productivity of radiologists, as measured by number of reports issued per 6-h shift, evaluating variables that could affect the results.

Materials And Methods: This was a study utilizing an online questionnaire sent to radiologists affiliated with the Brazilian College of Radiology and Diagnostic Imaging. The questions were related to the demographic profile and professional practice characteristics (form of remuneration, primary imaging method employed, and subspecialty) of the radiologists, as well as their individual productivity (average personal productivity) and the productivity considered reasonable in a 6-h shift.

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Objectives: CT-guided biopsy of indeterminate lung lesions sometimes provides insufficient histological results due to tumor necrosis. Functional and metabolic methods such as DWI-MR and PET-CT may help by directing sample collection to a lesion area of greater biological representativeness. The objective is to evaluate the histopathological results based on findings on ADC and SUV levels in lung lesions suspected for primary cancer.

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The streamline flow in the portal system is a phenomenon by which blood from superior mesenteric vein goes preferentially to the right hepatic lobe, while splenic and inferior mesenteric veins divert preferentially to the left lobe. Such a phenomenon results in different patterns of distribution of several liver diseases. The purpose of this article is to discuss the concepts behind the theory of streamline flow and to perform an imaging-based review of representative cases, demonstrating how it may influence the patterns of liver involvement in different gastrointestinal diseases.

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Objective: To establish an overview of computed tomography (CT)-guided percutaneous nephrostomy performed at a referral center for cancer, addressing the characteristics of patients submitted to this intervention, as well as the indications for it, the technical specificities of it, and its main complications.

Materials And Methods: This was a retrospective study involving a review of the electronic medical records and images of patients submitted to CT-guided percutaneous nephrostomy at a referral center for cancer between 2014 and 2016.

Results: A total of 201 procedures were evaluated.

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Purpose: Postinsertion computed tomography (CT) can identify air gaps (AGs) around the cylinder in vaginal cuff brachytherapy (VCB). This study investigates the incidence and location of AGs.

Methods And Materials: Planning CTs of 22 prospectively recruited patients (NCT02091050) treated with 2.

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