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2.
J Comput Assist Tomogr ; 44(2): 168-177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195795

RESUMO

In this article, we aim to review Liver Imaging Reporting and Data System version 18 (LI-RADS v2018). Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy. Liver Imaging Reporting and Data System developed for standardizing interpreting, reporting, and data collection of HCC describes 5 major features for accurate HCC diagnosis and several ancillary features, some favoring HCC in particular or malignancy in general and others favoring benignity. Untreated hepatic lesions LI-RADS affords 8 unique categories based on imaging appearance on computed tomography and magnetic resonance imaging, which indicate the possibility of HCC or malignancy with or without tumor in vein. Furthermore, LI-RADS defines 4 treatment response categories for treated HCCs after different locoregional therapy. These continuous recent updates on LI-RADS improve the communication between the radiologists and the clinicians for better management and patient outcome.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Sistemas de Informação em Radiologia , Humanos , Fígado/diagnóstico por imagem , Radiologistas
3.
J Comput Assist Tomogr ; 44(2): 188-192, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195797

RESUMO

OBJECTIVE: The aim of this study was to determine if texture analysis can classify liver observations likely to be hepatocellular carcinoma based on the Liver Imaging Reporting and Data System (LI-RADS) using single portal venous phase computed tomography. METHODS: This research ethics board-approved retrospective cohort study included 64 consecutive LI-RADS observations. Individual observation texture analysis features were compared using Kruskal-Wallis and 2 sample t tests. Logistic regression was used for prediction of LI-RADS group. Diagnostic accuracy was assessed using receiver operating characteristic curves and Youden method. RESULTS: Multiple texture features were associated with LI-RADS including the mean HU (P = 0.003), median (P = 0.002), minimum (P = 0.010), maximum (P = 0.013), standard deviation (P = 0.009), skewness (P = 0.007), and entropy (P < 0.001). On logistic regression, LI-RADS group could be predicted with area under the curve, sensitivity, and specificity of 0.98, 96%, and 100%, respectively. CONCLUSIONS: Texture analysis features on portal venous phase computed tomography can identify liver observations likely to be hepatocellular carcinoma, which may preclude the need to recall some patients for additional multiphase imaging.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Sistemas de Informação em Radiologia , Tomografia Computadorizada por Raios X/métodos , Idoso , Estudos de Coortes , Feminino , Humanos , Fígado/diagnóstico por imagem , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
4.
J Comput Assist Tomogr ; 44(2): 197-203, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195798

RESUMO

INTRODUCTION: Liver segmentation and volumetry have traditionally been performed using computed tomography (CT) attenuation to discriminate liver from other tissues. In this project, we evaluated if spectral detector CT (SDCT) can improve liver segmentation over conventional CT on 2 segmentation methods. MATERIALS AND METHODS: In this Health Insurance Portability and Accountability Act-compliant institutional review board-approved retrospective study, 30 contrast-enhanced SDCT scans with healthy livers were selected. The first segmentation method is based on Gaussian mixture models of the SDCT data. The second method is a convolutional neural network-based technique called U-Net. Both methods were compared against equivalent algorithms, which used conventional CT attenuation, with hand segmentation as the reference standard. Agreement to the reference standard was assessed using Dice similarity coefficient. RESULTS: Dice similarity coefficients to the reference standard are 0.93 ± 0.02 for the Gaussian mixture model method and 0.90 ± 0.04 for the CNN-based method (all 2 methods applied on SDCT). These were significantly higher compared with equivalent algorithms applied on conventional CT, with Dice coefficients of 0.90 ± 0.06 (P = 0.007) and 0.86 ± 0.06 (P < 0.001), respectively. CONCLUSION: On both liver segmentation methods tested, we demonstrated higher segmentation performance when the algorithms are applied on SDCT data compared with equivalent algorithms applied on conventional CT data.


Assuntos
Fígado/diagnóstico por imagem , Fígado/patologia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Meios de Contraste , Humanos , Tamanho do Órgão , Intensificação de Imagem Radiográfica/métodos , Estudos Retrospectivos
5.
J Comput Assist Tomogr ; 44(2): 209-216, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195799

RESUMO

PURPOSE: The aim of this study was to compare hepatic vascular and parenchymal image quality between direct and peristaltic contrast injectors during hepatic computed tomography (HCT). METHODS: Patients (n = 171) who underwent enhanced HCT and had both contrast media protocols and injector systems were included; group A: direct-drive injector with fixed 100 mL contrast volume (CV), and group B: peristaltic injector with weight-based CV. Opacification, contrast-to-noise ratio, signal-to-noise ratio, radiation dose, and CV for liver parenchyma and vessels in both groups were compared by paired t test and Pearson correlation. Receiver operating characteristic curve, visual grading characteristics, and Cohen κ were used. RESULTS: Contrast-to-noise ratio: compared with hepatic vein for functional liver, contrast-to-noise ratio was higher in group B (2.17 ± 0.83) than group A (1.82 ± 0.63); portal vein: higher in group B (2.281 ± 0.96) than group A (2.00 ± 0.66). Signal-to-noise ratio for functional liver was higher in group B (5.79 ± 1.58 Hounsfield units) than group A (4.81 ± 1.53 Hounsfield units). Radiation dose and contrast media were lower in group B (1.98 ± 0.92 mSv) (89.51 ± 15.49 mL) compared with group A (2.77 ± 1.03 mSv) (100 ± 1.00 mL). Receiver operating characteristic curve demonstrated increased reader in group B (95% confidence interval, 0.524-1.0) than group A (95% confidence interval, 0.545-1.0). Group B had increased revenue up to 58% compared with group A. CONCLUSIONS: Image quality improvement is achieved with lower CV and radiation dose when using peristaltic injector with weight-based CV in HCT.


Assuntos
Meios de Contraste/administração & dosagem , Fígado/diagnóstico por imagem , Doses de Radiação , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
6.
J Comput Assist Tomogr ; 44(2): 223-229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195800

RESUMO

OBJECTIVES: This study aimed to assess if dual-energy computed tomography (DECT) quantitative analysis and radiomics can differentiate normal liver, hepatic steatosis, and cirrhosis. MATERIALS AND METHODS: Our retrospective study included 75 adult patients (mean age, 54 ± 16 years) who underwent contrast-enhanced, dual-source DECT of the abdomen. We used Dual-Energy Tumor Analysis prototype for semiautomatic liver segmentation and DECT and radiomic features. The data were analyzed with multiple logistic regression and random forest classifier to determine area under the curve (AUC). RESULTS: Iodine quantification (AUC, 0.95) and radiomic features (AUC, 0.97) differentiate between healthy and abnormal liver. Combined fat ratio percent and mean mixed CT values (AUC, 0.99) were the strongest differentiators of healthy and steatotic liver. The most accurate differentiating parameters of normal liver and cirrhosis were a combination of first-order statistics (90th percentile), gray-level run length matrix (short-run low gray-level emphasis), and gray-level size zone matrix (gray-level nonuniformity normalized; AUC, 0.99). CONCLUSION: Dual-energy computed tomography iodine quantification and radiomics accurately differentiate normal liver from steatosis and cirrhosis from single-section analyses.


Assuntos
Fígado Gorduroso/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Meios de Contraste , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Feminino , Humanos , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Intensificação de Imagem Radiográfica/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Estudos Retrospectivos
7.
J Comput Assist Tomogr ; 44(2): 230-235, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32195801

RESUMO

OBJECTIVE: We developed a patient-specific contrast enhancement optimizer (p-COP) that can exploratorily calculate the contrast injection protocol required to obtain optimal enhancement at target organs using a computer simulator. Appropriate contrast media dose calculated by the p-COP may minimize interpatient enhancement variability. Our study sought to investigate the clinical utility of p-COP in hepatic dynamic computed tomography (CT). METHODS: One hundred thirty patients (74 men, 56 women; median age, 65 years) undergoing hepatic dynamic CT were randomly assigned to 1 of 2 contrast media injection protocols using a random number table. Group A (n = 65) was injected with a p-COP-determined iodine dose (developed by Higaki and Awai, Hiroshima University, Japan). In group B (n = 65), a standard protocol was used. The variability of measured CT number (SD) between the 2 groups of aortic and hepatic enhancement was compared using the F test. In the equivalence test, the equivalence margins for aortic and hepatic enhancement were set at 50 and 10 Hounsfield units (HU), respectively. The rate of patients with an acceptable aortic enhancement (250-350 HU) for the diagnosis of hypervascular liver tumors was compared using the χ test. RESULTS: The mean ± SD values of aortic and hepatic enhancement were 311.0 ± 39.9 versus 318.7 ± 56.5 and 59.0 ± 11.5 versus 58.6 ± 11.8 HU in groups A and B, respectively. Although the SD for aortic enhancement was significantly lower in group A (P = 0.006), the SD for hepatic enhancement was not significantly different (P = 0.871). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 groups was within the range of the equivalence margins. The number of patients with acceptable aortic enhancement was significantly greater in group A than in group B (P < 0.01). CONCLUSIONS: The p-COP software reduced interpatient variability in aortic enhancement and obtained acceptable aortic enhancement at a significantly higher rate compared with the standard injection protocol for hepatic dynamic CT.


Assuntos
Meios de Contraste/administração & dosagem , Iohexol/administração & dosagem , Neoplasias Hepáticas/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Injeções Intravenosas , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
8.
Medicine (Baltimore) ; 99(8): e19343, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32080155

RESUMO

RATIONALE: Foreign body (FB) ingestion is a relatively common clinical situation in the emergency department. However, multiple sharply pointed foreign bodies located in different organs are rare conditions and no definite treatment guidelines has been established. PATIENT CONCERNS: A 31-year-old amateur magician visited the outpatient clinic with a chief complaint of epigastric discomfort. He might have accidentally swallowed some needles while practicing a magic trick 2 days before. DIAGNOSIS: Imaging tests revealed 1 needle was stuck in the left liver lobe through the stomach wall, 1 was in the third portion of the duodenum, 3 were in the ascending colon, and 2 were in the transverse colon. INTERVENTIONS: A needle in the duodenum and 5 in the colon were removed by endoscopy. The needle stuck in the liver from the stomach was not visible inside the stomach and was successfully removed by laparoscopy a few days later. OUTCOMES: The patient was able to tolerate an oral diet and was discharged on postoperative day 4 without any complications. LESSONS: Developing a treatment plan in cases of multiple sharp FB may be difficult. A multidisciplinary team of endoscopists and surgeons is needed to determine the best possible treatment plan. This experience illustrates the importance of the planning of the sequence and method of removal of multiple foreign bodies from the gastrointestinal tract.


Assuntos
Endoscopia do Sistema Digestório , Corpos Estranhos/cirurgia , Laparoscopia , Agulhas , Acidentes , Adulto , Colo/diagnóstico por imagem , Colo/cirurgia , Duodeno/diagnóstico por imagem , Duodeno/cirurgia , Humanos , Fígado/diagnóstico por imagem , Fígado/cirurgia , Magia , Masculino , Radiografia , Estômago/diagnóstico por imagem , Estômago/cirurgia
9.
J Comput Assist Tomogr ; 44(2): 204-208, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31972750

RESUMO

PURPOSE: The purpose of this study was to determine whether liver extracellular volume (ECV) measured using equilibrium computed tomography (EQ-CT) can be used to quantitatively assess doxorubicin-induced liver injury (DILI). METHODS: The ethical approval was obtained from the Institutional Animal Care and Use Committee regulations. Thirteen dogs administered with doxorubicin for 0 to 24 weeks were imaged by contrast-enhanced EQ-CT. The dogs were divided into 3 groups: the baseline (13 dogs), 16-week (10 dogs), and 24-week (7 dogs) groups. Pathological analysis of the liver was performed using hematoxylin-eosin and Masson staining. Liver ECV uptake was calculated for each group and correlated with the histopathological and serological findings of hepatic fibrosis (hyaluronic acid and procollagen type III). RESULTS: In the baseline group, the median ECVs of the right and left liver lobes were 21.78% (interquartile range [IQR], 16.78%-26.68%) and 20.91% (IQR, 16.39%-24.07%), respectively. In the 16- and 24-week groups, the median ECVs of these 2 liver lobes were 28.18% (IQR, 20.56%-34.61%) and 25.96% (IQR, 14.07%-41.38%) and 29.71% (IQR, 27.19%-35.25%) and 29.22% (IQR, 22.62%-38.67%), respectively. There were no significant differences in ECV between the left and right lobes in the 3 groups (P < 0.05). Both the 16- and 24-week groups showed significantly higher ECV than did the primary group (P = 0.001-0.0006). However, there were no significant differences in ECV between the 16-week group and 24-week group (P = 0.412). There was a positive correlation between the serum index and edema due to the inflammation and necrosis associated with DILI (R = 0.6534, R = 0.7129). CONCLUSIONS: Extracellular volume measured by EQ-CT imaging can accurately predict the potential DILI through the quantification of ECV changes.


Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Doença Hepática Crônica Induzida por Substâncias e Drogas/diagnóstico por imagem , Doxorrubicina/efeitos adversos , Fígado/diagnóstico por imagem , Fígado/patologia , Tomografia Computadorizada por Raios X/métodos , Animais , Doença Hepática Crônica Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Cães , Feminino , Tamanho do Órgão
10.
PLoS One ; 15(1): e0221544, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31986149

RESUMO

BACKGROUND: Computed tomography (CT) images of livers may show a hypo-attenuated structure alongside the falciform ligament, which can be a focal fatty pseudolesion and can mimic a malignancy. The preferred location is on the right parafissural site, ventral in segment IVa/b. The etiology is not clear, nor is it known how the histology of this location develops. These are evaluated in this study. METHODS: 40 adult cadavers with autopsy and / or postmortem CT in a university hospital and a forensic center were included. Liver biopsies were taken at the left side of the falciform ligament as control, and at the right side as the possible precursor of a pseudolesion; these were examined for collagen and fat content. Cadavers with steatotic (>5% fat) or fibrotic (>2% collagen) control samples were excluded. RESULTS: Significantly more collagen was present in the right parafissural liver parenchyma: median 0.68% (IQR: 0.32-1.17%), compared to the left side 0.48% (IQR: 0.21-0.75%) (p 0.008), with equal fat content and CT attenuation values. The etiophysiology goes back to the demise of the umbilical venes in the early embryonic and neonatal period. CONCLUSIONS: The right parafissural area contains more collagen and an equal amount of fat compared to the control left side. This supports the hypothesis of delayed, 'third' inflow: the postnatal change in blood supply from umbilical to portal leaves the downstream parafissural area hypoperfused leading to hypoxia which in turn results in collagen accumulation and the persistence of paraumbilical veins of Sappey.


Assuntos
Colágeno/metabolismo , Diagnóstico Diferencial , Fígado Gorduroso/diagnóstico , Neoplasias Hepáticas/diagnóstico , Fígado/diagnóstico por imagem , Adulto , Autopsia , Biópsia , Cadáver , Fígado Gorduroso/diagnóstico por imagem , Fígado Gorduroso/patologia , Feminino , Humanos , Ligamentos/diagnóstico por imagem , Ligamentos/patologia , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Masculino , Mesentério/diagnóstico por imagem , Mesentério/patologia , Pessoa de Meia-Idade , Veia Porta/diagnóstico por imagem , Veia Porta/patologia , Umbigo/diagnóstico por imagem , Umbigo/patologia
11.
Acta Cir Bras ; 34(11): e201901103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31939502

RESUMO

PURPOSE: To evaluate liver regeneration after selective ligation of portal vein and hepatic artery by 3D Computed Tomography in an experimental model. METHODS: Sixteen Wistar rats were randomized into four equal groups: Group I- control (sham), Group II- isolated selective ligation of the hepatic artery, Group III- isolated selective ligation of the portal vein and Group IV- combined ligation of portal vein and hepatic artery. Before procedure and five days after a 3D CT Scan was performed to analyze the hypertrophy, weight and function of the remnant liver. RESULTS: The largest regeneration rate and increase of weight in the hypertrophied lobe was detected in group IV, the first with an average of 3.99 (p=0.006) and the last varying from 6.10g to 9.64g (p=0.01). However, total liver weight and the R1 ratio (Hypertrophied Lobe Weight/Total Liver Weight) was higher in group III (P<0.001) when compared with groups I, II and IV and showed no difference between them. The immunohistochemical examination with PCNA also found higher percentages with statistical significance differences in rats of groups III and IV. It was possible to confirm a strong correlation between hypertrophied lobe weight and its imaging volumetric study. Liver function tests only showed a significant difference in serum gamma-glutamyltransferase and phosphorous. CONCLUSION: There is a largest liver regeneration after combined ligation of portal vein and hepatic artery and this evidence may improve the knowledge of surgical treatment of liver injuries, with a translational impact in anima nobile.


Assuntos
Artéria Hepática/cirurgia , Regeneração Hepática/fisiologia , Fígado/diagnóstico por imagem , Veia Porta/cirurgia , Animais , Hepatomegalia/diagnóstico por imagem , Hepatomegalia/fisiopatologia , Imagem Tridimensional/métodos , Imuno-Histoquímica , Ligadura , Fígado/irrigação sanguínea , Fígado/patologia , Masculino , Tamanho do Órgão/fisiologia , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
13.
J Trauma Acute Care Surg ; 88(2): 305-309, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31804421

RESUMO

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a viable resuscitation approach for a subdiaphragmatic injury that can regulate arterial blood flow. On the other hand, the evaluation of venous or portal venous blood flow during REBOA remains insufficient because invasive cannulation or exposure of the vessel may affect the blood flow, and Doppler echography is highly operator-dependent. However, phase contrast magnetic resonance imaging has enabled accurate evaluation and noninvasive measurement. This study aimed to investigate the change of venous and portal venous blood flow during REBOA in a porcine model. METHODS: Seven pigs were anesthetized, and a REBOA catheter was placed. The blood flows of the inferior vena cava (IVC), hepatic vein (HV), portal vein (PV), and superior vena cava (SVC) were measured using phase contrast magnetic resonance imaging, in both the balloon deflated (no-REBOA) and fully balloon inflated (REBOA) states. Mean arterial pressure (MAP), central venous pressure, cardiac index, and systemic vascular resistance index were measured. RESULTS: The blood flows of the suprahepatic, infrahepatic, and distal IVC, HV, and PV in the no-REBOA state were 1.40 ± 0.36 L·min, 0.94 ± 0.16 L·min, 0.50 ± 0.19 L·min, 0.060 ± 0.018 L·min, and 0.32 ± 0.091 L·min, respectively. The blood flow of each section in the REBOA condition was significantly decreased at 0.41 ± 0.078 (33% of baseline), 0.15 ± 0.13 (15%), 0.043 ± 0.034 (9%), 0.029 ± 0.017 (37%), and 0.070 ± 0.034 L·min (21%), respectively. The blood flow of the SVC increased significantly in the REBOA condition (1.4 ± 0.63 L·min vs. 0.53 ± 0.14 L·min [257%]). Mean arterial pressure, central venous pressure, cardiac index, and systemic vascular resistance index were significantly increased after REBOA inflation. CONCLUSION: Resuscitative endovascular balloon occlusion of the aorta decreased blood flows of the IVC, HV, and PV and increased blood flow of the SVC. This result could be explained by the collateral flow from the lower body to the SVC. A better understanding of the effect of REBOA on the venous and portal venous systems may help control liver injury.


Assuntos
Oclusão com Balão/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Sistema Porta/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Ressuscitação/efeitos adversos , Animais , Aorta/cirurgia , Oclusão com Balão/métodos , Procedimentos Endovasculares/métodos , Feminino , Humanos , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Fígado/lesões , Imagem por Ressonância Magnética , Masculino , Modelos Animais , Sistema Porta/diagnóstico por imagem , Ressuscitação/métodos , Choque Hemorrágico/etiologia , Choque Hemorrágico/terapia , Suínos , Porco Miniatura
14.
Radiol Med ; 125(1): 15-23, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31587182

RESUMO

OBJECTIVES: To evaluate the performance of the LI-RADS v.2018 scale by comparing it with the Likert scale, in the characterization of liver lesions. METHODS: A total of 39 patients with chronic liver disease underwent MR examination for characterization of 44 liver lesions. Images were independently analyzed by two radiologists using the LI-RADS scale and by another two radiologists using the Likert scale. The reference standard used was either histopathological evaluation or a 4-year MRI follow-up. Receiver operating characteristic analysis was performed. RESULTS: The LI-RADS scale obtained an accuracy of 80%, a sensitivity of 72%, a specificity of 93%, a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 70%, while the Likert scale achieved an accuracy of 79%, a sensitivity of 73%, a specificity of 87%, a PPV of 89% and a NPV of 70%. The area under the curve (AUC) was 85% for the LI-RADS scale and 83% for the Likert scale. The inter-observer agreement was strong (k = 0.89) between the LI-RADS evaluators and moderate (k = 0.69) between the Likert evaluators. CONCLUSIONS: There was no statistically significant difference between the performances of the two scales; nevertheless, we suggest that the LI-RADS scale be used, as it appeared more objective and consistent.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Lesões Pré-Cancerosas/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Fígado/diagnóstico por imagem , Imagem por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Curva ROC , Padrões de Referência , Estudos Retrospectivos , Sensibilidade e Especificidade , Ultrassonografia
15.
Br J Radiol ; 93(1106): 20190701, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31825655

RESUMO

OBJECTIVE: To evaluate accuracy of virtual-non-contrast images (VNC) compared to true-unenhanced-images (TNC) for evaluation of liver attenuation acquired using spectral-detector CT (SDCT). METHODS: 149 patients who underwent multiphase transcatheter-aortic-valve-replacement (TAVR) SDCT-examinations [unenhanced-chest (TNC), CT-angiography chest (CTA-chest, early arterial-phase) and abdomen (CTA-abdomen, additional early arterial-phase after a second injection of contrast media)] were retrospectively included. VNC of CTA-chest (VNC-chest) and CTA-abdomen (VNC-abdomen) were reconstructed and compared to TNC. Region of interest-based measurement of mean attenuation (Hounsfield unit, HU) was applied in the following regions: liver, spleen, abdominal aorta and paraspinal muscle. RESULTS: VNC accuracy was high in the liver, spleen, abdominal aorta and muscle for abdomen-scanning. For the liver, average attenuation was 59.0 ± 9.1 HU for TNC and 72.6 ± 9.5 HU for CTA-abdomen. Liver attenuation in VNC-abdomen (59.1 ± 6.4 HU) was not significantly different from attenuation in TNC (p > 0.05). In contrast, VNC was less accurate for chest-scanning: Due to the protocol, in CTA-chest no contrast media was present in the liver parenchyma as indicated by the same attenuation in TNC (59.0 ± 9.1 HU) and CTA-chest (58.8 ± 8.9 HU, p > 0.05). Liver attenuation in VNC-chest (56.2 ± 6.4 HU, p < 0.05) was, however, significantly lower than in TNC and CTA-chest implying an artificial reduction of attenuation. CONCLUSION: VNC performed well in a large cohort of TAVR-examinations yielding equivalent mean attenuations to TNC; however, application of this technique might be limited when no or very little contrast media is present in parenchyma, more precisely in an early arterial-phase of the liver. ADVANCES IN KNOWLEDGE: This study showed that VNC can be reliably applied in cardiac protocols when certain limitations are considered.


Assuntos
Fígado/diagnóstico por imagem , Substituição da Valva Aórtica Transcateter/métodos , Abdome , Idoso , Idoso de 80 Anos ou mais , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tórax , Realidade Virtual
16.
Eur Radiol ; 30(1): 370-382, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31385048

RESUMO

OBJECTIVES: The 8th International Forum for Liver Magnetic Resonance Imaging (MRI), held in Basel, Switzerland, in October 2017, brought together clinical and academic radiologists from around the world to discuss developments in and reach consensus on key issues in the field of gadoxetic acid-enhanced liver MRI since the previous Forum held in 2013. METHODS: Two main themes in liver MRI were considered in detail at the Forum: the use of gadoxetic acid for contrast-enhanced MRI in patients with liver cirrhosis and the technical performance of gadoxetic acid-enhanced liver MRI, both opportunities and challenges. This article summarises the expert presentations and the delegate voting on consensus statements discussed at the Forum. RESULTS AND CONCLUSIONS: It was concluded that gadoxetic acid-enhanced MRI has higher sensitivity for the diagnosis of hepatocellular carcinoma (HCC), when compared with multidetector CT, by utilising features of hyperenhancement in the arterial phase and hypointensity in the hepatobiliary phase (HBP). Recent HCC management guidelines recognise an increasing role for gadoxetic acid-enhanced MRI in early diagnosis and monitoring post-resection. Additional research is needed to define the role of HBP in predicting microvascular invasion, to better define washout during the transitional phase in gadoxetic acid-enhanced MRI for HCC diagnosis, and to reduce the artefacts encountered in the arterial phase. Technical developments are being directed to shortening the MRI protocol for reducing time and patient discomfort and toward utilising faster imaging and non-Cartesian free-breathing approaches that have the potential to improve multiphasic dynamic imaging. KEY POINTS: • Gadoxetic acid-enhanced MRI provides higher diagnostic sensitivity than CT for diagnosing HCC. • Gadoxetic acid-enhanced MRI has roles in early-HCC diagnosis and monitoring post-resection response. • Faster imaging and free-breathing approaches have potential to improve multiphasic dynamic imaging.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Artefatos , Carcinoma Hepatocelular/patologia , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Fígado/patologia , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Masculino , Tomografia Computadorizada Multidetectores , Suíça
17.
Eur Radiol ; 30(1): 383-393, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31392478

RESUMO

Our intention is to demystify the MR quantification of hepatic iron (i.e., the liver iron concentration) and give you a step-by-step approach by answering the most pertinent questions. The following article should be more of a manual or guide for every radiologist than a classic review article, which just summarizes the literature. Furthermore, we provide important background information for professional communication with clinicians. The information regarding the physical background is reduced to a minimum. After reading this article, you should be able to perform adequate MR measurements of the LIC with 1.5-T or 3.0-T scanners. KEY POINTS: • MRI is widely accepted as the primary approach to non-invasively determine liver iron concentration (LIC). • This article is a guide for every radiologist to perform adequate MR measurements of the LIC. • When using R2* relaxometry, some points have to be considered to obtain correct measurements-all explained in this article.


Assuntos
Sobrecarga de Ferro/diagnóstico por imagem , Ferro/análise , Fígado/química , Fígado/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Protocolos Clínicos , Humanos , Guias de Prática Clínica como Assunto
18.
Eur Radiol ; 30(1): 558-570, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31444598

RESUMO

PURPOSE: To enhance clinician's decision-making by diagnosing hepatocellular carcinoma (HCC) in cirrhotic patients with indeterminate liver nodules using quantitative imaging features extracted from triphasic CT scans. MATERIAL AND METHODS: We retrospectively analyzed 178 cirrhotic patients from 27 institutions, with biopsy-proven liver nodules classified as indeterminate using the European Association for the Study of the Liver (EASL) guidelines. Patients were randomly assigned to a discovery cohort (142 patients (pts.)) and a validation cohort (36 pts.). Each liver nodule was segmented on each phase of triphasic CT scans, and 13,920 quantitative imaging features (12 sets of 1160 features each reflecting the phenotype at one single phase or its change between two phases) were extracted. Using machine-learning techniques, the signature was trained and calibrated (discovery cohort), and validated (validation cohort) to classify liver nodules as HCC vs. non-HCC. Effects of segmentation and contrast enhancement quality were also evaluated. RESULTS: Patients were predominantly male (88%) and CHILD A (65%). Biopsy was positive for HCC in 77% of patients. LI-RADS scores were not different between HCC and non-HCC patients. The signature included a single radiomics feature quantifying changes between arterial and portal venous phases: DeltaV-A_DWT1_LL_Variance-2D and reached area under the receiver operating characteristic curve (AUC) of 0.70 (95%CI 0.61-0.80) and 0.66 (95%CI 0.64-0.84) in discovery and validation cohorts, respectively. The signature was influenced neither by segmentation nor by contrast enhancement. CONCLUSION: A signature using a single feature was validated in a multicenter retrospective cohort to diagnose HCC in cirrhotic patients with indeterminate liver nodules. Artificial intelligence could enhance clinicians' decision by identifying a subgroup of patients with high HCC risk. KEY POINTS: • In cirrhotic patients with visually indeterminate liver nodules, expert visual assessment using current guidelines cannot accurately differentiate HCC from differential diagnoses. Current clinical protocols do not entail biopsy due to procedural risks. Radiomics can be used to non-invasively diagnose HCC in cirrhotic patients with indeterminate liver nodules, which could be leveraged to optimize patient management. • Radiomics features contributing the most to a better characterization of visually indeterminate liver nodules include changes in nodule phenotype between arterial and portal venous phases: the "washout" pattern appraised visually using EASL and EASL guidelines. • A clinical decision algorithm using radiomics could be applied to reduce the rate of cirrhotic patients requiring liver biopsy (EASL guidelines) or wait-and-see strategy (AASLD guidelines) and therefore improve their management and outcome.


Assuntos
Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/diagnóstico por imagem , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/diagnóstico por imagem , Aprendizado de Máquina , Tomografia Computadorizada por Raios X/métodos , Idoso , Inteligência Artificial , Carcinoma Hepatocelular/patologia , Meios de Contraste/farmacologia , Diagnóstico Diferencial , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
20.
Clin Nucl Med ; 45(1): e1-e7, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31789907

RESUMO

PURPOSE: This study was conducted to identify the role of hepatobiliary scintigraphy (HBS) in the management of biliary tract injuries. METHODS: We retrospectively studied 54 patients (28 male and 26 female patients) aged 3 to 78 years with evidence of bile leak on HBS performed between January 2015 and October 2017. Following intravenous injection of Tc-mebrofenin, dynamic images were acquired for 30 minutes followed by static images until 24 hours. SPECT/CT was performed in patients with suspicion of bile leak on the planar images. Patients were classified as those with free intraperitoneal or localized bile leak. Any abdominal drain output was documented, and its statistical significance was assessed using Mann-Whitney U test. Subsequent management was also documented. RESULTS: Of the 54 patients, 28 demonstrated free intraperitoneal bile leak and 26 localized leak on HBS. Thirty-four patients (24 with free intraperitoneal leak and 10 with localized leak) had an abdominal drain. Drain output was significantly higher in patients with free intraperitoneal leak compared with patients with localized leak (370 vs 78 mL/d per patient, P < 0.01). All patients with free intraperitoneal bile leak underwent interventional procedures such as endoscopic retrograde cholangiopancreatography and stenting or Roux-en-Y hepaticojejunostomy later on. Patients with localized bile leak were managed conservatively and were free of symptoms at 1-year follow-up. CONCLUSIONS: Our findings indicate that, in addition to detecting biliary leak, HBS may be used to identify patients with localized bile leak (48% of patients in our study) who do not require active intervention.


Assuntos
Sistema Biliar/diagnóstico por imagem , Sistema Biliar/lesões , Fígado/diagnóstico por imagem , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Idoso , Procedimentos Cirúrgicos do Sistema Biliar , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
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