OBJECTIVE: The objective of the present study is to analyze the optimization of fluoroscopic image quality and patient entrance surface air kerma rate in interventional radiology procedures, utilizing a phantom adapted for fluoroscopy. MATERIALS AND METHODS: The authors utilized a phantom developed for evaluating conventional radiological images adapted for fluoroscopy through the addition of two catheters with different diameters, both of them utilized in interventional radiology. The patient entrance surface air kerma rate was determined with the aid of this phantom. RESULTS: The evaluation of technical parameters for different exposure modes of a digital fluoroscopic imaging system has allowed the determination of the air kerma rate, enabling the optimization of the image quality in interventional procedures. The decrease in the patient entrance surface air kerma rate may achieve 67%. CONCLUSION: The optimization of fluoroscopic image quality achieved with a phantom allows reducing the patient entrance surface air kerma with no significant loss of diagnostic performance.

Keywords: Images optimization, Fluoroscopy, Phantom, Dose reduction

In order to evaluate atypical aspects of hepatocellular carcinoma at computed tomography and magnetic resonance imaging, we have retrospectively evaluated 100 patients with diagnosed hepatocellular carcinoma, based on combined imaging studies, laboratory results, biopsy and surgery. We have selected those cases with atypical findings at computed tomography or magnetic resonance imaging, including cystic lesions, bleeding tumors, with calcifications, with spontaneous regression, pedunculated tumors, hypovascular lesions, giant hepatocellular carcinomas, and those with unusual local invasiveness. The hepatocellular carcinoma is the most usual primary malignant lesion of the liver and usually it has a typical aspect and is associated with hepatic cirrhosis. However, in a significant number of cases, some uncommon findings can be responsible for a delayed diagnosis.

Keywords: Hepatocellular carcinoma, Liver, Atypical findings, Ultrasound, Computed tomography, Magnetic resonance imaging

OBJECTIVE: To evaluate the results of hepatocellular carcinoma arterial chemoembolization in cirrhotic patients awaiting liver transplantation. MATERIALS AND METHODS: Twenty-three cirrhotic patients with hepatocellular carcinoma awaiting liver transplantation were submitted to multiple sessions of chemoembolization using mitomycin C and lipiodol. A prospective evaluation of the following factors was performed: a) serum levels of alpha-fetoprotein; b) tumor size; c) maintenance of the viability criteria for hepatic transplantation; d) degree of liver dysfunction. RESULTS: The mean serum levels of alpha-fetoprotein were reduced by 43% during the first 13 months. The mean tumor size, as measured by the long axis, after a mean follow-up period of 13.5 months was 3.2 cm, which is considered stable for the period according to the World Health Organization criteria. The mean survival rate was 14 months. CONCLUSION: In this trial, pre-transplantation use of chemoembolization in combination with an adequately chosen therapy showed few complications and contra-indications as well as a considerable anti-tumor efficacy. Despite the fact that the adopted therapy increased survival rates in comparison to historical evolution data in hepatocellular carcinoma, this increase had not the same dimension if the median waiting time for transplantation is taken into consideration. Therefore, other strategies need to be associated to either make survival rate longer or to reduce transplantation waiting time.

Keywords: Hepatocellular carcinoma, Chemoembolization, Lipiodol

OBJECTIVE: To implement a protocol for correction of images acquired by videofluoroscopy based on the mathematical model described by Baltzopoulos (1995) and to evaluate the magnitude of error in the linear and non-linear calibration methods. MATERIALS AND METHODS: The images were acquired using a Axion Siemens Iconos R100 videofluoroscope from one individual during knee extension exercise. A non-linear calibration pattern was used for the correction of the images. Data was processed using a Silicon Graphics 320 capture plate and subsequently analyzed using the Matlab software. RESULTS: In order to demonstrate the method's applicability, the deformation of the patellar ligament was evaluated. The use of a linear calibration pattern produced a maximum error of 0.086 mm, while the non-linear calibration pattern reached a maximum value of 0.019 mm. According to the mean error, the linear calibration was 0.024 mm, and the non-linear presented a value of 0.007 mm. CONCLUSION: The results show the need to use a non-linear calibration procedure.

Keywords: Videofluoroscopy, Images calibration, Patellar ligament, Knee

We present the preliminary results of testing and acceptance of a method for displaying medical images that employs simple computer freewares that can be run in unsophisticated computational platforms, which are commonly underutilized. This method allows easy and accessible visualization, printing, documenting, archiving, consulting and electronic transmission of a wide range of medical images without the need of expensive, complex and difficult to learn softwares.

Keywords: Medical images, Freeware, Ultrasound

OBJECTIVE: To present the process of implementation of toolkits for visualization of medical images using DICOM and to review the basis and characteristics of this protocol. In this paper we present a VDTApplication for visualization of local and remote images, and a VDTApplet that allows the visualization of images on a web browser. MATERIALS AND METHODS: The toolkits were implemented using Java programming language. For the development of this toolkit we considered the different version of the DICOM protocol, creating a generic system capable of reading and opening images generated by different modalities of different manufacturers. The tools were evaluated qualitatively by doctors taking into account the system's interface, image quality and image adjustment. RESULTS: The evaluation score ranged from 1 (very poor ) to 5 (very good) for each item, with the following results: 5 for system interface, 4 for image quality and 3 for the image adjustment. Based on the scores obtained we concluded that the tools can be considered good. CONCLUSION: These results allowed us to conclude that these tools are practical, user friendly and should be added to the PACS (picture archiving and communication system) of "Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo", Ribeirão Preto, SP, Brazil.

Keywords: Medical images, DICOM, Filmless radiology, Medical images visualization

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 percepção de médicos residentes em radiologia de 4º ano sobre as melhores modalidades de imagem na investigação de neoplasias e trauma. Materiais e Métodos: Vinte e sete médicos residentes de 4º ano de quatro programas de residência em radiologia americanos participaram do estudo. Aos participantes foi perguntado sobre a melhor modalidade de imagem para se avaliar o cérebro e a coluna vertebral, pulmões, abdome e o sistema musculoesquelético. As modalidades de imagem disponíveis foram: RM, TC, ultrassonografia, PET e radiografia simples. Todos os achados foram comparados com os Critérios de Adequação de Exames de Imagem e Radioterapia do ACR. Resultados: A RM foi escolhida como melhor modalidade de imagem para se avaliar neoplasias encefálicas, espinhais, abdominais e musculoesqueléticas por 96,3%, 100%, 70,4% e 63% dos residentes, respectivamente. A TC foi escolhida por 88,9% dos residentes para avaliar neoplasias pulmonares. A modalidade de imagem ótima para se avaliar trauma foi a TC para lesões encefálicas (100%), espinhais (92,6%), pulmonares (96,3%), abdominais (92,6%) e grandes lesões traumáticas musculoesqueléticas (74,1%); a RM foi escolhida para lesões esportivas (96,3%). Observou-se concordância com os critérios de adequação do ACR. Conclusão: Houve concordância entre a percepção dos residentes sobre as melhores modalidades de imagem para avaliação de neoplasias e trauma e os critérios de adequação do ACR.

Keywords: Formação de residentes; Educação médica; Modalidades de imagem.

OBJECTIVE: To determine the rates of diagnostic underestimation at stereotactic percutaneous core needle biopsies (CNB) and vacuum-assisted biopsies (VABB) of nonpalpable breast lesions, with histopathological results of atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS) subsequently submitted to surgical excision. As a secondary objective, the frequency of ADH and DCIS was determined for the cases submitted to biopsy. MATERIALS AND METHODS: Retrospective review of 40 cases with diagnosis of ADH or DCIS on the basis of biopsies performed between February 2011 and July 2013, subsequently submitted to surgery, whose histopathological reports were available in the internal information system. Biopsy results were compared with those observed at surgery and the underestimation rate was calculated by means of specific mathematical equations. RESULTS: The underestimation rate at CNB was 50% for ADH and 28.57% for DCIS, and at VABB it was 25% for ADH and 14.28% for DCIS. ADH represented 10.25% of all cases undergoing biopsy, whereas DCIS accounted for 23.91%. CONCLUSION: The diagnostic underestimation rate at CNB is two times the rate at VABB. Certainty that the target has been achieved is not the sole determining factor for a reliable diagnosis. Removal of more than 50% of the target lesion should further reduce the risk of underestimation.

Keywords: Breast neoplasia; Core needle biopsy; Vacuum-assisted biopsy; Diagnostic techniques and procedures; Noninvasive intraductal carcinoma.

OBJECTIVE: To investigate whether quantitative computed tomography (CT) measurements can predict microvascular invasion (MVI) in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This was a retrospective analysis of 200 cases of surgically proven HCCs in 125 consecutive patients evaluated between March 2010 and November 2017. We quantitatively measured regions of interest in lesions and adjacent areas of the liver on unenhanced CT scans, as well as in the arterial, portal venous, and equilibrium phases on contrast-enhanced CT scans. Enhancement profiles were analyzed and compared with histopathological references of MVI. Univariate and multivariate logistic regression analyses were used in order to evaluate CT parameters as potential predictors of MVI. RESULTS: Of the 200 HCCs, 77 (38.5%) showed evidence of MVI on histopathological analysis. There was no statistical difference between HCCs with MVI and those without, in terms of the percentage attenuation ratio in the portal venous phase (114.7 vs. 115.8) and equilibrium phase (126.7 vs. 128.2), as well as in terms of the relative washout ratio, also in the portal venous and equilibrium phases (15.0 vs. 8.2 and 31.4 vs. 26.3, respectively). CONCLUSION: Quantitative dynamic CT parameters measured in the preoperative period do not appear to correlate with MVI in HCC.

Keywords: Carcinoma, hepatocellular; Tomography, X-ray computed; Liver neoplasms/surgery; Liver transplantation.

OBJECTIVE: To evaluate liver lesions, in accordance with the LI-RADS classification, using contrast-enhanced multiphase dynamic computed tomography in patients with hepatitis B, coinfected or not with hepatitis D, or with chronic hepatitis C, as well as to determine the level of agreement between radiologists. MATERIALS AND METHODS: We evaluated 38 patients with hepatitis B, coinfected or not with hepatitis D, or with chronic hepatitis C, all of whom underwent contrast-enhanced multiphase dynamic computed tomography. For each examination, two radiologists selected up to three hepatic lesions, categorizing them in accordance with the LI-RADS classification and evaluating signs of chronic liver disease and portal hypertension. To determine the level of agreement between radiologists, we calculated the kappa statistic (κ) . RESULTS: Radiologist 1 and radiologist 2 selected 56 and 48 liver lesions, respectively. According to radiologist 1 and radiologist 2, respectively, 27 (71%) and 23 (61%) of the 38 patients had at least one liver lesion; 13 (34%) and 12 (32%) had a LI-RADS 5 lesion (κ = 0.821); 19 (50%) and 16 (42%) had a hypervascular lesion (κ = 0.668); and 30 (79%) and 24 (63%) had splenomegaly (κ = 0.503). Both radiologists identified chronic liver disease in 31 (82%) of the patients (κ = 1.00). CONCLUSION: Lesions categorized as LI-RADS 5 were detected in approximately 32% of the patients, with almost perfect agreement between the radiologists. The level of agreement was substantial or moderate for the other LI-RADS categories.

Keywords: Carcinoma, hepatocellular; Liver cirrhosis; Tomography, X-ray computed.

Hepatocellular carcinoma is the most common primary malignant liver tumour and is a leading cause of death worldwide. Despite the advent of screening programmes, most cases of hepatocellular carcinoma are diagnosed late (in an advanced stage) which precludes curative treatments such as surgery and ablation. Therefore, intra-arterial locoregional treatments now play a central role in the management of advanced hepatocellular carcinoma, such treatments ranging from trans-arterial chemo-embolisation to the more recently developed trans-arterial radio-embolisation technique. In this essay, we discuss the state of the art of intra-arterial treatment for locally advanced hepatocellular carcinoma and the future directions for such treatment.

Keywords: Carcinoma, hepatocellular/therapy; Fibrosis; Liver/pathology; Medical oncology/methods; Chemoembolization, therapeutic; Liver neoplasms/radiotherapy.

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 develop a deep learning system to classify non-small cell lung cancer (NSCLC) by histologic subtype—adenocarcinoma or squamous cell carcinoma (SCC)—from computed tomography (CT) images in which the tumor regions were segmented, comparing our results with those of similar studies conducted in other countries and evaluating the accuracy of automated classification by using data from the Instituto Nacional de Câncer, Brazil.
MATERIALS AND METHODS: To develop the classification system, we employed a 2D U-Net neural network for semantic segmentation, with data augmentation and preprocessing steps. It was pretrained on 28,506 CT images from The Cancer Image Archive, a private database, and validated on 2,015 of those images. To develop the classification algorithm, we used a VGG16-based network, modified for better performance, with 3,080 images of adenocarcinoma and SCC from the Instituto Nacional de Câncer database.
RESULTS: The algorithm achieved an accuracy of 84.5% for detecting adenocarcinoma and 89.6% for detecting SCC, with sensitivities of 91.7% and 90.4%, respectively, which are considered satisfactory when compared with the values obtained in similar studies.
CONCLUSION: The system developed appears to provide accurate automated detection, as well as tumor segmentation and classification of NSCLC subtypes of a local population using deep learning networks trained using public image data sets. This method could assist oncological radiologists by improving the efficiency of preliminary diagnoses

Keywords: Carcinoma, non-small-cell lung; Image processing, computer-assisted/methods; Segmentation; Semantics; Carcinoma/classification; Deep learning.

This study aimed to systematically review the highest-quality evidence regarding the cutoff value in kPa for the diagnostic accuracy of ultrasound-based liver elastography in comparison with reference standards, including magnetic resonance imaging (MRI), computed tomography, and liver biopsy. In addition, we assessed the presence of hepatocellular carcinoma (HCC) and its associated implications in clinical and diagnostic contexts. We conducted a search using Medical Subject Headings across PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Lilacs for articles published up to June 6, 2024. Of 1,131 studies identified, 33 were eligible and 8 met the quality criteria, as evaluated with the “RTI Item Bank” and “QUADAS-2” tools, following the PICO strategy. The mean elasticity of the liver parenchyma among patients with confirmed HCC was 18.77 kPa (95% CI: 16.28–21.27), making ultrasound liver elastography useful as a predictor of the diagnosis by gold-standard methods such as MRI. Ultrasound elastography is a low-cost, accessible, and noninvasive diagnostic tool capable of estimating liver elasticity in patients with HCC. However, due to the heterogeneity of the articles included in this review, further prospective studies are needed in order to confirm and standardize a cutoff stiffness value for early HCC screening, which could improve patient outcomes, particularly in resource-limited settings.

Keywords: Carcinoma, hepatocellular; Elasticity imaging techniques; Liver neoplasms/diagnostic imaging.