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1.
Radiol Med ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958915

RESUMO

PURPOSE: Microwave ablation (MWA) and conventional transarterial chemoembolization (cTACE) are locoregional treatments commonly performed in very early, early and intermediate stages of hepatocellular carcinoma (HCC). Despite combined locoregional approaches have shown encouraging results in obtaining complete tumor necrosis, their application in a single session is poorly described. Our aim was to evaluate the safety and efficacy of single-session MWA and cTACE treatment in 5-cm HCCs and its influence on liver function. MATERIALS AND METHODS: All 5-cm HCCs treated by MWA and cTACE performed in a single-session in our Interventional Radiology unit between January 2020 and December 2022 were retrospectively recorded and analyzed. Patients with poor or missing pre- and post-treatment imaging were excluded. Technical success, clinical success, and complications rate were examined as primary endpoints. Pre- and post-treatment liver function laboratory parameters were also evaluated. RESULTS: A total of 15 lesions (mean lesion diameter, 5.0 ± 1.4 cm) in 15 patients (11 men; mean age, 67.1 ± 8.9 years) were retrospectively evaluated. Technical and clinical success were 100% and 73%, respectively. Four (27%) cases of partial response and no cases of progressive or stable disease were recorded. AST and ALT values have found to be significantly higher in post-treatment laboratory tests. No other significant differences between pre- and post-treatment laboratory values were registered. AST and ALT pre- and post-treatment higher differences (ΔAST and ΔALT) were significantly associated with a lower clinical success rate. CONCLUSION: MWA and cTACE single-session approach is safe and effective for 5-cm HCCs, without significant liver function impairment. A post-treatment increase in AST and ALT values may be a predictor for clinical failure.

2.
Radiol Med ; 126(3): 388-398, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33044732

RESUMO

OBJECTIVES: To investigate the role of third-generation iterative reconstruction (ADMIRE) in dual-source, high-pitch chest CT protocol with spectral shaping at 100 kVp in Coronavirus disease 2019 (COVID-19). METHODS: Confirmed COVID-19 inpatients undergoing to unenhanced chest CT were scanned with a dual-energy acquisition (DECT, 90/150Sn kV) and a dual-source, high-pitch acquisition with tin-filtered 100 kVp (LDCT). On the DECT with ADMIRE 3 (DECT3) were evaluated the pulmonary findings and their extension (25-point score). Two radiologists in consensus evaluated with 5-point scales the overall image quality, the anatomical structures, and the elementary findings on LDCT reconstructed with filtered backprojection (LDCT0), with ADMIRE 3 (LDCT3) and 5 (LDCT5), and on DECT3. The signal-to-noise ratio (SNR), the body mass index, the exposure times, and the radiation doses were recorded. RESULTS: Seventy-five patients (57 M/18F; median age: 63 y.o.) were included, with median pulmonary extension of 13/25 points. The imaging findings were detected in proportion comparable to the available literature. The ADMIRE significantly improved the SNR in LDCT (p < 0.00001) with almost no significant differences in overweight patients. The LDCT had median effective dose of 0.39 mSv and acquisition time of 0.71 s with significantly less motion artifacts than DECT (p < 0.00001). The DECT3 and LDCT3 provided the best image quality and depiction of pulmonary anatomy and imaging findings, with significant differences among all the series (p < 0.00001). CONCLUSION: The LDCT with spectral shaping and ADMIRE3 provided acceptable image quality in the evaluation of patients with COVID-19, with significantly reduced radiation dose and motion artifacts.


Assuntos
COVID-19/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Pulmão/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Estudos Retrospectivos
3.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925387

RESUMO

Melanoma is one of the most aggressive skin cancers. The 5-year survival rate of stage III melanoma patients ranges from 93% (IIIA) to 32% (IIID) with a high risk of recurrence after complete surgery. The introduction of target and immune therapies has dramatically improved the overall survival, but the identification of patients with a high risk of relapse who will benefit from adjuvant therapy and the determination of the best treatment choice remain crucial. Currently, patient prognosis is based on clinico-pathological features, highlighting the urgent need of predictive and prognostic markers to improve patient management. In recent years, many groups have focused their attention on identifying molecular biomarkers with prognostic and predictive potential. In this review, we examined the main candidate biomarkers reported in the literature.


Assuntos
Melanoma/genética , Melanoma/patologia , Melanoma/terapia , Biomarcadores , Biomarcadores Farmacológicos , DNA Tumoral Circulante/genética , Humanos , MicroRNAs/genética , Estadiamento de Neoplasias/métodos , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/patologia , Taxa de Sobrevida , Melanoma Maligno Cutâneo
4.
Radiol Med ; 125(12): 1288-1300, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32415476

RESUMO

Magnetic resonance imaging (MRI) is particularly attractive for clinical application in perfusion imaging thanks to the absence of ionizing radiation and limited volumes of contrast agent (CA) necessary. Dynamic contrast-enhanced MRI (DCE-MRI) involves sequentially acquiring T1-weighted images through an organ of interest during the passage of a bolus administration of CA. It is a particularly flexible approach to perfusion imaging as the signal intensity time course allows not only rapid qualitative assessment, but also quantitative measures of intrinsic perfusion and permeability parameters. We examine aspects of the T1-weighted image series acquisition, CA administration, post-processing that constitute a DCE-MRI study in clinical practice, before considering some heuristics that may aid in interpreting the resulting contrast enhancement time series. While qualitative DCE-MRI has a well-established role in the diagnostic assessment of a range of tumours, and a central role in MR mammography, clinical use of quantitative DCE-MRI remains limited outside of clinical trials. The recent publication of proposals for standardized acquisition and analysis protocols for DCE-MRI by the Quantitative Imaging Biomarker Alliance may be an opportunity to consolidate and advance clinical practice.


Assuntos
Meios de Contraste/farmacocinética , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias/diagnóstico por imagem , Permeabilidade Capilar/fisiologia , Meios de Contraste/administração & dosagem , Espaço Extracelular/diagnóstico por imagem , Espaço Extracelular/metabolismo , Humanos , Neoplasias/irrigação sanguínea , Imagem de Perfusão/métodos , Fluxo Sanguíneo Regional/fisiologia
5.
Radiol Med ; 125(4): 365-373, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32239472

RESUMO

AIM: To subjectively and objectively evaluate the feasibility and diagnostic reliability of a low-dose, long-pitch dual-source chest CT protocol on third-generation dual-source CT (DSCT) with spectral shaping at 100Sn kVp for COVID-19 patients. MATERIALS AND METHODS: Patients with COVID-19 and positive swab-test undergoing to a chest CT on third-generation DSCT were included. The imaging protocol included a dual-energy acquisition (HD-DECT, 90/150Sn kVp) and fast, low-dose, long-pitch CT, dual-source scan at 100Sn kVp (LDCT). Subjective (Likert Scales) and objective (signal-to-noise and contrast-to-noise ratios, SNR and CNR) analyses were performed; radiation dose and acquisition times were recorded. Nonparametric tests were used. RESULTS: The median radiation dose was lower for LDCT than HD-DECT (Effective dose, ED: 0.28 mSv vs. 3.28 mSv, p = 0.016). LDCT had median acquisition time of 0.62 s (vs 2.02 s, p = 0.016). SNR and CNR were significantly different in several thoracic structures between HD-DECT and LDCT, with exception of lung parenchyma. Qualitative analysis demonstrated significant reduction in motion artifacts (p = 0.031) with comparable diagnostic reliability between HD-DECT and LDCT. CONCLUSIONS: Ultra-low-dose, dual-source, fast CT protocol provides highly diagnostic images for COVID-19 with potential for reduction in dose and motion artifacts.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , COVID-19 , Protocolos Clínicos , Estudos de Viabilidade , Humanos , Pandemias , Doses de Radiação , SARS-CoV-2
6.
Radiol Med ; 125(7): 636-646, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32500509

RESUMO

COVID-19 is an emerging infection caused by a novel coronavirus that is moving so rapidly that on 30 January 2020 the World Health Organization declared the outbreak a Public Health Emergency of International Concern and on 11 March 2020 as a pandemic. An early diagnosis of COVID-19 is crucial for disease treatment and control of the disease spread. Real-time reverse-transcription polymerase chain reaction (RT-PCR) demonstrated a low sensibility; therefore chest computed tomography (CT) plays a pivotal role not only in the early detection and diagnosis, especially for false negative RT-PCR tests, but also in monitoring the clinical course and in evaluating the disease severity. This paper reports the CT findings with some hints on the temporal changes over the course of the disease: the CT hallmarks of COVID-19 are bilateral distribution of ground glass opacities with or without consolidation in the posterior and peripheral lung, but the predominant findings in later phases include consolidations, linear opacities, "crazy-paving" pattern, "reversed halo" sign and vascular enlargement. The CT findings of COVID-19 overlap with the CT findings of other diseases, in particular the viral pneumonia including influenza viruses, parainfluenza virus, adenovirus, respiratory syncytial virus, rhinovirus, human metapneumovirus, etc. There are differences as well as similarities in the CT features of COVID-19 compared with those of the severe acute respiratory syndrome. The aim of this article is to review the typical and atypical CT findings in COVID-19 patients in order to help radiologists and clinicians to become more familiar with the disease.


Assuntos
Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Radiografia Torácica , Tomografia Computadorizada por Raios X , COVID-19 , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Progressão da Doença , Humanos , Pandemias , Pneumonia Viral/epidemiologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave
7.
Radiol Med ; 125(12): 1249-1259, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32367320

RESUMO

BACKGROUND: As one of the most frequent risk factors for cardiovascular disease, type 2 diabetes mellitus (T2DM) is one of the largest causes of death. However, an acute cardiac presentation is not uncommon in diabetic patients, and the current investigative approach remains often inadequate. The aim of our study was to retrospectively stratify the risk of asymptomatic T2DM patients using low-dose 640-slice coronary computed tomography angiography (CCTA). MATERIALS AND METHODS: CCTA examinations of 62 patients (mean age, 65 years) with previous diagnosis of type 2 diabetes and without cardiac symptoms were analyzed. Image acquisition was performed using a 640-slice CT. Per-patient, per-vessel and per-plaque analyses were performed. Stratification risk was evaluated according to the ESC guidelines. The patients were followed up after 2.21 ± 0.56 years from CCTA examination. RESULTS: Coronary artery disease (CAD) was found in 58 patients (93.55%) presenting 290 plaques. Analysis of all samples showed severe-to-occlusive atherosclerosis in 24 patients (38.7% of cases). However, over the degree of stenosis, 23 patients were evaluated at high risk considering the extension of CAD. Good agreement was shown by the correlation of CAD extension/risk estimation and MACE incidence, according to a Kaplan-Meier survival analysis (p value = 0.001), with a 7.25-fold increased risk (HR 7.25 CI 2.13-24.7; p value = 0.002). CONCLUSION: Our study confirms the high capability of CCTA to properly stratify the CV risk of asymptomatic T2DM patients. Its use could be recommended if we consider how current investigative strategies to correctly assess these patients often seem inadequate.


Assuntos
Doenças Assintomáticas , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Diabetes Mellitus Tipo 2/complicações , Placa Aterosclerótica/diagnóstico por imagem , Idoso , Angiografia por Tomografia Computadorizada , Doença da Artéria Coronariana/etiologia , Estenose Coronária/diagnóstico por imagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Placa Aterosclerótica/etiologia , Doses de Radiação , Estudos Retrospectivos , Medição de Risco
8.
Diabetologia ; 62(11): 2007-2016, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31273408

RESUMO

AIMS/HYPOTHESIS: Gestational diabetes mellitus (GDM) is linked with a higher lifetime risk for the development of impaired fasting glucose, impaired glucose tolerance, type 2 diabetes, the metabolic syndrome, cardiovascular disease, postpartum depression and tumours. Despite this, there is no consistency in the long-term follow-up of women with a previous diagnosis of GDM. Further, the outcomes selected and reported in the research involving this population are heterogeneous and lack standardisation. This amplifies the risk of reporting bias and diminishes the likelihood of significant comparisons between studies. The aim of this study is to develop a core outcome set (COS) for RCTs and other studies evaluating the long-term follow-up at 1 year and beyond of women with previous GDM treated with insulin and/oral glucose-lowering agents. METHODS: The study consisted of three work packages: (1) a systematic review of the outcomes reported in previous RCTs of the follow-up at 1 year and beyond of women with GDM treated with insulin and/or oral glucose-lowering agents; (2) a three-round online Delphi survey with key stakeholders to prioritise these outcomes; and (3) a consensus meeting where the final COS was decided. RESULTS: Of 3344 abstracts identified and evaluated, 62 papers were retrieved and 25/62 papers were included in this review. A total of 121 outcomes were identified and included in the Delphi survey. Delphi round 1 was emailed to 835 participants and 288 (34.5%) responded. In round 2, 190 of 288 (65.9%) participants responded and in round 3, 165 of 190 (86.8%) participants responded. In total, nine outcomes were selected and agreed for inclusion in the final COS: assessment of glycaemic status; diagnosis of type 2 diabetes since the index pregnancy; number of pregnancies since the index pregnancy; number of pregnancies with a diagnosis of GDM since the index pregnancy; diagnosis of prediabetes since the index pregnancy; BMI; post-pregnancy weight retention; resting blood pressure; and breastfeeding. CONCLUSIONS/INTERPRETATION: This study identified a COS that will help bring consistency and uniformity to outcome selection and reporting in clinical trials and other studies involving the follow-up at 1 year and beyond of women diagnosed with GDM treated with insulin and/or oral glucose-lowering agents during pregnancy.


Assuntos
Glicemia/análise , Diabetes Gestacional/terapia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Algoritmos , Índice de Massa Corporal , Atenção à Saúde , Técnica Delphi , Feminino , Seguimentos , Intolerância à Glucose , Humanos , Insulina/sangue , Obstetrícia/organização & administração , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
9.
Eur Radiol ; 29(8): 3976-3985, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30689033

RESUMO

PURPOSE: To develop and optimize a rapid magnetic resonance imaging (MRI) screening protocol for pancreatic cancer to be performed in conjunction with breast MRI screening in breast cancer susceptibility gene (BRCA)-positive individuals. METHODS: An IRB-approved prospective study was conducted. The rapid screening pancreatic MR protocol was designed to be less than 10 min to be performed after a standard breast MRI protocol. Protocol consisted of coronal NT T2 SSFSE, axial NT T2 SSFSE and axial NT rFOV FOCUS DWI, and axial T1. Images were acquired with the patient in the same prone position of breast MRI using the built-in body coil. Image quality was qualitatively assessed by two radiologists with 12 and 13 years of MRI experience, respectively. The imaging protocol was modified until an endpoint of five consecutive patients with high-quality diagnostic images were achieved. Signal-to-noise ratio and contrast-to-noise ratio were assessed. RESULTS: The rapid pancreas MR protocol was successfully completed in all patients. Diagnostic image quality was achieved for all patients. Excellent image quality was achieved for low b values; however, image quality at higher b values was more variable. In one patient, a pancreatic neuroendocrine tumor was found and the patient was treated surgically. In four patients, small pancreatic cystic lesions were detected. In one subject, a hepatic mass was identified and confirmed as adenoma by liver MRI. CONCLUSION: Rapid MR protocol for pancreatic cancer screening is feasible and has the potential to play a role in screening BRCA patients undergoing breast MRI. KEY POINT: • Develop and optimize a rapid magnetic resonance imaging (MRI) screening protocol for pancreatic cancer to be performed in conjunction with breast MRI screening in BRCA mutation positive individuals.


Assuntos
Proteína BRCA1/genética , DNA de Neoplasias/genética , Detecção Precoce de Câncer/métodos , Imageamento por Ressonância Magnética/métodos , Mutação , Neoplasias Pancreáticas/diagnóstico , Adulto , Idoso , Proteína BRCA1/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Projetos Piloto , Estudos Prospectivos
11.
Radiol Med ; 124(8): 753-761, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31011995

RESUMO

PURPOSE: To compare radiation exposure associated with daily practice cardiovascular (CV) examinations performed on two different multidetector computed tomography (MDCT) scanners, a conventional 64-MDCT and a third-generation dual-source (DS) MDCT. MATERIALS AND METHODS: In this retrospective study, 1458 patients who underwent CV examinations between January 2017 and August 2018 were enrolled. A single-source 64-MDCT (Lightspeed VCT, GE) scan was performed in 705 patients from January to August 2017 (207 coronary examinations and 498 vascular examinations) and 753 patients underwent third-generation 192 × 2-DSCT (Somatom FORCE, Siemens) scan from January to August 2018 (302 coronary examinations and 451 vascular examinations). Volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), tube voltage (TV) and exposure time (ET), pitch factor (PF) were registered for each patient. Student's t test was used to compare mean values between each corresponding group of MDCT and DSCT. RESULTS: In coronary examinations with DSCT, CTDIvol was 24.4% lower (23.1 mGy vs 30.6 mGy, p < 0.0001) and DLP and ED reductions were 35.6% than with MDCT (465.0 mGy * cm vs 732.3 mGy * cm and 6.5 mSv and 10.3 mSv; vs p < 0.0001). Concerning scan parameters, kVp and ET reductions were 12.7% and 69.4%, respectively (p < 0.0001); PF increase was 73.8% (p < 0.0001). In all vascular studies, DSCT, compared with MDCT, permitted to reduce CTDIvol from 43.5 to 70.6%; DLP and ED reductions were from 50.3 to 73.1%; kVp and ET decreases were from 10.7 to 32.5% and from 26.3 to 68.7%. PF increase was from 16.7 to 58.1% (all differences with p < 0.0001). CONCLUSIONS: In daily practice, CV examinations CTDI, DLP, ED, ET and TV were lower and PF was higher with 192 × 2-DSCT compared to 64-MDCT.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Tomografia Computadorizada Multidetectores/métodos , Exposição à Radiação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Angiografia por Tomografia Computadorizada/efeitos adversos , Angiografia por Tomografia Computadorizada/instrumentação , Angiografia Coronária/efeitos adversos , Angiografia Coronária/instrumentação , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Segurança de Equipamentos , Humanos , Tomografia Computadorizada Multidetectores/efeitos adversos , Tomografia Computadorizada Multidetectores/instrumentação , Doses de Radiação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/efeitos adversos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Estudos Retrospectivos , Fatores de Tempo
12.
Radiol Med ; 124(8): 745-752, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31004322

RESUMO

AIM: To provide an overview on dose reduction and image quality after the installation of a third-generation dual-source CT (dsCT) in a Pediatric Radiology Department. MATERIALS AND METHODS: We included pediatric patients (< 20 years old) undergoing CT for oncological staging (neck, chest and abdomen) or low-dose chest CT for lung diseases. Each of these two groups were further divided in two age groups (≤ or > 10 years old) including patients scanned in the same period of two consecutive years, in 2017 with a 16-row LightSpeed CT (GE Healthcare) or in 2018 with a Somatom Force dsCT (Siemens Healthineers). Technical parameters such as kVp, mAs, slice thickness, exposure times and dose indicators were retrieved and compared. Image quality was evaluated in consensus by two radiologists on a five-point semiquantitative scale. Nonparametric tests were used. RESULTS: In oncological patients, significantly lower kVp and tube current with better image quality were achieved with the dsCT. Radiation dose (total DLP) was 5-6 times lower with dsCT, thanks also to virtual non-contrast images. In low-dose chest CT, the frequent use of tin filter required higher tube current; a total DLP 3 times lower was achieved with dsCT in patients ≤ 10 years old. The image quality was better with the dsCT in low-dose chest CT protocols. CONCLUSION: The third-generation dsCT provides high-quality images with reduced motion artifacts at lower dose.


Assuntos
Pneumopatias/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/normas , Tomografia Computadorizada Multidetectores/tendências , Neoplasias/diagnóstico por imagem , Doses de Radiação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Adolescente , Fatores Etários , Artefatos , Criança , Feminino , Humanos , Masculino , Tomografia Computadorizada Multidetectores/instrumentação , Movimentos dos Órgãos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Radiografia Torácica/normas , Radiografia Torácica/tendências , Adulto Jovem
13.
Radiol Med ; 124(12): 1238-1252, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31630332

RESUMO

Cardiovascular computer tomography (CT) in pediatric congenital heart disease (CHD) patients is often challenging. This might be due to limited patient cooperation, the high heart rate, the complexity and variety of diseases and the need for radiation dose minimization. The recent developments in CT technology with the introduction of the third-generation dual-source (DS) dual-energy (DE) CT scanners well suited to respond to these challenges. DSCT is characterized by high-pitch, long anatomic coverage and a more flexible electrocardiogram-synchronized scan. DE provides additional clinical information about vascular structures, myocardial and lung perfusion and allows artifacts reduction. These advances have increased clinical indications and modified CT protocol for pediatric CHD patients. In our hospital, DSCT with DE technology has rapidly become an important imaging technique for both pre- and postoperative management of pediatric patients with CHDs. The aim of this article is to describe the state-of-the-art in DSCT protocol with DE technology in pediatric CHD patients, providing some case examples of our experience over an 18-month period.


Assuntos
Cardiopatias Congênitas/diagnóstico por imagem , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Artefatos , Criança , Pré-Escolar , Meios de Contraste/administração & dosagem , Filtração/instrumentação , Frequência Cardíaca , Humanos , Lactente , Recém-Nascido , Movimentos dos Órgãos , Doses de Radiação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Respiração , Tomografia Computadorizada por Raios X/instrumentação
14.
Radiol Med ; 124(12): 1281-1295, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31792703

RESUMO

The physical principles of dual-energy computed tomography (DECT) are as old as computed tomography (CT) itself. To understand the strengths and the limits of this technology, a brief overview of theoretical basis of DECT will be provided. Specific attention will be focused on the interaction of X-rays with matter, on the principles of attenuation of X-rays in CT toward the intrinsic limits of conventional CT, on the material decomposition algorithms (two- and three-basis-material decomposition algorithms) and on effective Rho-Z methods. The progresses in material decomposition algorithms, in computational power of computers and in CT hardware, lead to the development of different technological solutions for DECT in clinical practice. The clinical applications of DECT are briefly reviewed in relation to the specific algorithms.


Assuntos
Algoritmos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tecnologia Radiológica/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Masculino , Espalhamento de Radiação , Raios X
16.
J Comput Assist Tomogr ; 42(2): 222-229, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29489589

RESUMO

OBJECTIVE: To evaluate the accuracy of single-source dual-energy computed tomography (ssDECT) in iodine quantification using various segmentation methods in an ex vivo model. METHODS: Ten sausages, injected with variable quantities of iodinated contrast, were inserted into 2 livers and scanned with ssDECT. Material density iodine images were reconstructed. Three radiologists segmented each sausage. Iodine concentration, volume, and absolute quantity were measured. Agreement between the measured and injected iodine was assessed with the concordance correlation coefficient (CCC). Intrareader agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: Air bubbles were observed in sausage (IX). Sausage (X) was within the same view as hyper-attenuating markers used for localization. With IX and X excluded, CCC and ICC were greater than 0.98 and greater than 0.88. When included, CCC and ICC were greater than 0.94 and greater than 0.79. CONCLUSIONS: Iodine quantification was reproducible and precise. However, accuracy reduced in sausages consisting of air filled cavities and within the same view as hyperattenuating markers.


Assuntos
Iodo/análise , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Animais , Bovinos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Reprodutibilidade dos Testes
19.
Ann Surg ; 264(5): 787-796, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27429025

RESUMO

OBJECTIVE: A novel and easy prognostic score based on the combination of pre-operatively available variables in patients with hepatocellular cancer (HCC) waiting for liver transplantation (LT) has been developed from a long waiting time (WT) training set and then validated in a short-WT set. SUMMARY OF BACKGROUND DATA: The role of radiological response to loco-regional therapies, alpha-fetoprotein modification, inflammatory markers, and length of WT has been recently shown to be important selection criteria for the risk of intention-to-treat (ITT)-death and recurrence. METHODS: The training set consisted of 179 HCC patients listed for LT during the period January 2000 to December 2012 from the UCL Brussels Transplant Centre; the validation set consisted of 110 patients listed during the period January 2005 to December 2014 from the Ancona Liver Centre. RESULTS: The proposed Time-Radiological-response-Alpha-fetoprotein-INflammation (TRAIN) score was the best predictor of microvascular invasion. A TRAIN score ≥1.0 excellently stratified both the investigated populations in terms of ITT and recurrence survivals. When compared with Milan criteria, the proposed score allowed obtaining an increase of potentially transplantable patients (+8.9% in training set and 24.6% in validation set) without additive recurrence risks. CONCLUSIONS: The proposed TRAIN score is an easy selection tool based on variables available before LT. This score enables the selection process to be refined in the 2 different scenarios of long and short WT. In case of longer WT, the score is better at predicting risk of death during the WT; in case of short WT, the score is better at identifying risk of post-LT recurrence.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Seleção de Pacientes , Listas de Espera , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/diagnóstico , Feminino , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Medição de Risco , Sensibilidade e Especificidade , alfa-Fetoproteínas/metabolismo
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