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1.
Ann Anat ; 256: 152312, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39059507

RESUMEN

INTRODUCTION: Postmortem evaluation of the human vascular system has a long history, with advancements ranging from dissections to modern imaging techniques like computed tomography (CT scan). This study designs a novel combination of Angiofil, a liquid radiopaque polymer, and latex, a flexible cast material, for cadaveric vascular analysis. MATERIAL & METHODS: The aim was to synergize the advantages of both components, providing accurate radiological images and optimal dissection conditions. Three arterial territories (lateral circumflex femoral artery, profunda brachii artery, and radial artery) were injected and assessed through CT scans and dissections. RESULTS: The Angiofil-latex mixture allowed successful visualization of the vascular networks, offering a simple, reproducible, and non-toxic approach. Quantitative assessments of the three territories, including diameters and lengths, showed comparable results between CT scan and dissection. DISCUSSION: The technique precision and versatility make it an accessible and valuable tool for anatomical studies, potentially extending its application to MRI analyses. Overall, the Angiofil-latex combination presents a cost-effective solution for researchers, offering enhanced visibility and detailed anatomical insights for various applications, including anatomical variation studies.

2.
J Belg Soc Radiol ; 107(1): 91, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38023295

RESUMEN

Teaching Point: There are two important signs that could be seen on a non-contrast chest CT scan that can lead to the diagnosis of a pulmonary embolism: the hyperdense pulmonary artery sign and pulmonary infarction.

3.
Eur Radiol ; 32(12): 8726-8736, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35639145

RESUMEN

OBJECTIVES: To date, there are no data on the noninvasive surrogate of intratumoural immune status that could be prognostic of survival outcomes in non-small cell lung cancer (NSCLC). We aimed to develop and validate the immune ecosystem diversity index (iEDI), an imaging biomarker, to indicate the intratumoural immune status in NSCLC. We further investigated the clinical relevance of the biomarker for survival prediction. METHODS: In this retrospective study, two independent NSCLC cohorts (Resec1, n = 149; Resec2, n = 97) were included to develop and validate the iEDI to classify the intratumoural immune status. Paraffin-embedded resected specimens in Resec1 and Resec2 were stained by immunohistochemistry, and the density percentiles of CD3+, CD4+, and CD8+ T cells to all cells were quantified to estimate intratumoural immune status. Then, EDI features were extracted using preoperative computed tomography to develop an imaging biomarker, called iEDI, to determine the immune status. The prognostic value of iEDI was investigated on NSCLC patients receiving surgical resection (Resec1; Resec2; internal cohort Resec3, n = 419; external cohort Resec4, n = 96; and TCIA cohort Resec5, n = 55). RESULTS: iEDI successfully classified immune status in Resec1 (AUC 0.771, 95% confidence interval [CI] 0.759-0.783; and 0.770 through internal validation) and Resec2 (0.669, 0.647-0.691). Patients with higher iEDI-score had longer overall survival (OS) in Resec3 (unadjusted hazard ratio 0.335, 95%CI 0.206-0.546, p < 0.001), Resec4 (0.199, 0.040-1.000, p < 0.001), and TCIA (0.303, 0.098-0.944, p = 0.001). CONCLUSIONS: iEDI is a non-invasive surrogate of intratumoural immune status and prognostic of OS for NSCLC patients receiving surgical resection. KEY POINTS: • Decoding tumour immune microenvironment enables advanced biomarkers identification. • Immune ecosystem diversity index characterises intratumoural immune status noninvasively. • Immune ecosystem diversity index is prognostic for NSCLC patients.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Linfocitos T CD8-positivos/patología , Estudios Retrospectivos , Ecosistema , Estadificación de Neoplasias , Pronóstico , Tomografía Computarizada por Rayos X , Biomarcadores , Microambiente Tumoral
4.
J Belg Soc Radiol ; 106(1): 34, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35600761

RESUMEN

Teaching Point: Appendiceal intussusception appears as a "sausage or target shaped" lesion in the caecal lumen and may be caused by a "lead point".

5.
Eur J Radiol ; 142: 109832, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34246013

RESUMEN

OBJECTIVES: Intramammary mass lesions are reportedly present in up to 5.8% of all contrast enhanced CT-examinations of the female chest. We aimed to assess whether their biological relevance can be estimated using spectral CT-datasets. METHODS: In this bicentric retrospective study patients with breast masses visualized on spectral CT-examinations from 07/2017 to 06/2019 were included. Lesions were characterized as malignant or benign based on histology and/or a stable follow-up of >2 years. Conventional CT-images, iodine density-maps, virtual monoenergetic-images (40 keV, 100 keV) and Zeffective-maps were evaluated by two independent readers. Statistical analysis derived from the Regions of interest (ROIs) was done by calculating the Areas under the Receiver operating characteristic (ROC) curve (AUC) and Youden-indices. RESULTS: 106 breast masses (malignant/benign: 81/25, 76.4%/23.6%) were included. The mean AUCs of the variables "iodine content" (reader 1/2:0.97;0.98), "monoenergetic curve-slope" (0.97;0.96) and "Zeffective" (0.98;0.98) measured in the target lesions (TL) showed superior results compared to those derived from the variable "density" (0.92;0.93) (p < 0.001). The ratios "TL to aorta" calculated for the variables "iodine content", "monoenergetic curve-slope" and "Zeffective" showed superior results compared to normal breast tissue and muscle (p < 0.001). The optimal cutpoint for the "iodine content" in the TL was 0.7-0.9 mg/ml (sensitivity 96.6%, specificity 91.7%). The best diagnostic results were achieved by normalizing the iodine content in the TL to that in the aorta (optimal cutpoint 0.1, sensitivity 95.5%, 98.9%, specificity 91.7%). CONCLUSIONS: Our preliminary results suggest that spectral CT-datasets might allow to estimate the biological dignity of breast masses detected on clinically indicated chest-examinations.


Asunto(s)
Yodo , Tomografía Computarizada por Rayos X , Medios de Contraste , Femenino , Humanos , Curva ROC , Estudios Retrospectivos
6.
Respir Med ; 181: 106383, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33839588

RESUMEN

BACKGROUND: COVID-19 pandemic resulted in an unprecedented number of hospitalizations in general wards and intensive care units (ICU). Severe and critical COVID-19 patients suffer from extensive pneumonia; therefore, long-term respiratory sequelae may be expected. RESEARCH QUESTION: We conducted a cohort study to determine respiratory sequelae in patients with severe and critical COVID-19. We aimed at evaluating the proportion of patients with persisting respiratory symptoms and/or abnormalities in pulmonary function tests (PFT) or in lung imaging. STUDY DESIGN: and methods: This is a single center cohort study including COVID-19 survivors who underwent a three-month follow-up with clinical evaluation, PFT and lung high-resolution computed tomography (HRCT). All clinical, functional, and radiological data were centrally reviewed. Multiple linear regression analysis was performed to identify factors associated with residual lesions on HRCT. RESULTS: Full clinical evaluation, PFT and lung HRCT were available for central review in 126, 122 and 107 patients, respectively. At follow-up, 25% of patients complained from dyspnea and 35% from fatigue, lung diffusion capacity (DLCO) was decreased in 45%, 17% had HRCT abnormalities affecting more than 5% of their lung parenchyma while signs of fibrosis were found in 21%. In multiple linear regression model, number of days in ICU were related to the extent of persisting lesions on HRCT, while intubation was associated with signs of fibrosis at follow-up (P = 0.0005, Fisher's exact test). In contrast, the severity of lung imaging or PFT changes were not predictive of fatigue and dyspnea. INTERPRETATION: Although most hospitalized COVID-19 patients recover, a substantial proportion complains from persisting dyspnea and fatigue. Impairment of DLCO and signs suggestive of fibrosis are common but are not strictly related to long-lasting symptoms.


Asunto(s)
COVID-19/diagnóstico por imagen , COVID-19/fisiopatología , Pulmón/diagnóstico por imagen , Pulmón/fisiopatología , Anciano , COVID-19/complicaciones , Estudios de Cohortes , Disnea/etiología , Fatiga/etiología , Femenino , Estudios de Seguimiento , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Intensificación de Imagen Radiográfica , Pruebas de Función Respiratoria , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X
7.
Clin Chem Lab Med ; 58(12): 2141-2150, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33064667

RESUMEN

Objectives As severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) pandemic is increasing its victims on a global scale with recurring outbreaks, it remains of outmost importance to rapidly identify people requiring an intensive care unit (ICU) hospitalization. The aim of this study was to identify Coronavirus Disease 2019 (COVID-19) biomarkers, to investigate their correlation with disease severity and to evaluate their usefulness for follow-up. Methods Fifty patients diagnosed with SARS-Cov-2 were included in March 2020. Clinical and biological data were collected at admission, during hospitalization and one month after discharge. Patients were divided into two severity groups: non-ICU (28) and ICU and/or death (22) to stratify the risk. Results Blood parameters in COVID-19 patients at admission showed increased C-reactive protein (CRP) (100%), ferritin (92%), lactate dehydrogenase (LDH) (80%), white blood cell (WBC) count (26%) with lymphopenia (52%) and eosinopenia (98%). There were significant differences in levels of CRP, ferritin, D-dimers, fibrinogen, lymphocyte count, neutrophil count and neutrophil-to-lymphocyte ratio (NLR) among the two severity groups. Mapping of biomarker's kinetics distinguished early and late parameters. CRP, ferritin, LDH, lymphopenia and eosinopenia were present upon admission with a peak at the first week. Late biomarkers such as anemia, neutrophilia and elevated liver biomarkers appeared after one week with a peak at three weeks of hospitalization. Conclusions We confirmed that high-values of CRP, NLR, D-dimers, ferritin as well as lymphopenia and eosinopenia were consistently found and are good markers for risk stratification. Kinetics of these biomarkers correlate well with COVID-19 severity. Close monitoring of early and late biomarkers is crucial in the management of critical patients to avoid preventable deaths.


Asunto(s)
Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Recuento de Células Sanguíneas , COVID-19 , Infecciones por Coronavirus/sangre , Femenino , Estudios de Seguimiento , Hemostasis , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/sangre , Pronóstico , Adulto Joven
8.
J Belg Soc Radiol ; 104(1): 52, 2020 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-32984759

RESUMEN

Teaching point: Intra-osseous access for contrast medium injection represents an alternative route for emergency CT in patients with compromised venous access.

9.
Eur Radiol ; 30(11): 6204-6212, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32548647

RESUMEN

OBJECTIVES: To evaluate how pulmonary artery (PA) distensibility performs in detecting pulmonary hypertension due to left heart disease (PH-LHD) in comparison with parameters from ungated computed tomography (CT) and echocardiography. METHODS: One hundred patients (79 men, mean age = 63 ± 17 years) with either severe heart failure with reduced ejection fraction (HFrEF), aortic stenosis, or primary mitral regurgitation prospectively underwent right heart catheterization, ungated CT, ECG-gated CT, and echocardiography. During the ECG-gated CT, the right PA distensibility was calculated. In ungated CT, dPA, dPA/AA, the ratio of dPA to the diameter of the vertebra, segmental PA diameter, segmental PA-to-bronchus ratio, and the main PA volume were measured; the egg-and-banana sign was recorded. During echocardiography, the tricuspid regurgitation (TR) gradient was measured. The areas under the ROC curves (AUC) of these signs were computed and compared with DeLong test. Correlation between PA distensibility and PA pressure (PAP) was investigated through Pearson's coefficient. RESULTS: PA distensibility was lower in patients with PH than in those without PH (11.4 vs. 21.2%, p < 0.001) and correlated negatively with mean PAP (r = - 0.72, p < 0.001). Age, PA size, and mean PAP were independent predictors of PA distensibility. PA distensibility < 18% detected PH-LHD with 96% sensitivity and 73% specificity; its AUC was 0.92, larger than that of any other sign at ungated CT and TR gradient (AUC ranging from 0.54 to 0.83, DeLong: p ranging from 0.020 to < 0.001). CONCLUSION: PA distensibility on an ECG-gated CT can detect PH-LHD better than the parameters reflecting PA dilatation in ungated CT or TR gradient in the echocardiography of patients with severe HFrEF, aortic stenosis, or mitral regurgitation. KEY POINTS: • In left heart disease, pulmonary artery distensibility is lower in patients with PH than in those without pulmonary hypertension (11.4 vs. 21.2%, p < 0.001). • In left heart disease, pulmonary artery distensibility detects pulmonary hypertension with an area under the receiver operating curve of 0.92. • In left heart disease, the area under the receiver operating curve of pulmonary artery distensibility for detecting pulmonary hypertension is larger than that of all other signs at ungated CT (p from 0.019 to < 0.001) and tricuspid regurgitation gradient at echocardiography (p = 0.020).


Asunto(s)
Hipertensión Pulmonar/diagnóstico por imagen , Arteria Pulmonar/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Cateterismo Cardíaco/métodos , Técnicas de Imagen Sincronizada Cardíacas , Ecocardiografía/métodos , Femenino , Corazón/fisiopatología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/fisiopatología , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/complicaciones , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Tamaño de los Órganos , Arteria Pulmonar/patología , Arteria Pulmonar/fisiopatología , Volumen Sistólico , Tomografía Computarizada por Rayos X/métodos
10.
Insights Imaging ; 11(1): 8, 2020 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-31974813

RESUMEN

AIM: We hypothesized that multiple-choice questions written by radiology residents (MCQresident) for their weekly case presentations during radiology staff meetings could be used along with multiple-choice questions written by radiology teachers (MCQteacher) for their annual evaluation. The current prospective study aimed at determining the educational characteristics of MCQresident and at comparing them with those of MCQteacher. METHODS: Fifty-one radiology residents of the first to the fifth year of training took the 2017 exam that contained 58 MCQresident and 63 of MCQteacher. The difficulty index, the discrimination power, and the distractor's quality were calculated in the two series of MCQs and were compared by using Student t test. Two radiologists classified each MCQ according to Bloom's taxonomy and frequencies of required skills of both MCQ series were compared. RESULTS: The mean ± SD difficulty index of MCQresident was statistically significantly higher than that of MCQteacher (0.81 ± 0.1 vs 0.64 ± 0.2; p < 0.0001). The mean ± SD discrimination index of MCQresident was statistically significantly higher than that of MCQteacher (0.34 ± 0.2 vs 0.23 ± 0.2; p = 0.0007). The mean number of non-functional distractors per MCQresident was statistically significantly higher than that per MCQteacher (1.36 ± 0.9 vs 0.86 ± 0.9; p = 0.0031). MCQresident required recalling skills more frequently than MCQteacher which required more advanced skills to obtain a correct answer. CONCLUSIONS: Educational characteristics of MCQresident differ from those of MCQteacher. This study highlights the characteristics to optimize the writing of MCQs by radiology residents.

11.
Skeletal Radiol ; 48(8): 1261-1268, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30725159

RESUMEN

OBJECTIVE: To determine in a cadaveric study the lowest achievable radiation dose and optimal tube potential generating diagnostic image quality in multidetector computed tomography (MDCT) arthrography of the shoulder. MATERIALS AND METHODS: Six shoulders from three human cadavers were scanned using a 256-MDCT system after intra-articular injection of diluted iodinated contrast material. Using six decreasing radiation dose levels (CTDIvol: 20, 15, 10, 8, 6, and 4 mGy) and for each dose level, four decreasing tube potentials (140, 120, 100, and 80 kVp), image noise and contrast-to-noise ratio (CNR) were measured. Two independent and blinded observers assessed the overall diagnostic image quality, subjective amount of noise, and severity of artifacts according to a four-point scale. Influence of those MDCT data acquisition parameters on objective and subjective image quality was analyzed using the Kruskal-Wallis and Wilcoxon signed-rank tests, and pairwise comparisons were performed. RESULTS: Multidetector CT protocols with radiation doses of 15 mGy or higher, combined with tube potentials of 100 kVp or higher, were equivalent in CNR to the reference 20 mGy-140 kVp protocol (all p ≥ 0.054). Above a CTDIvol of 10 mGy and a tube potential of 120 kVp, all protocols generated diagnostic image quality and subjective noise equivalent to the 20 mGy-140 kVp protocol (all p ≥ 0.22). CONCLUSIONS: Diagnostic image quality in MDCT arthrography of the shoulder can be obtained with a radiation dose of 10 mGy at an optimal tube potential of 120 kVp, corresponding to a reduction of up to 50% compared with standard-dose protocols, and as high as 500% compared with reported protocols in the literature.


Asunto(s)
Artrografía , Tomografía Computarizada Multidetector , Dosis de Radiación , Articulación del Hombro/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Cadáver , Medios de Contraste , Femenino , Humanos , Masculino , Relación Señal-Ruido
12.
Expert Rev Pharmacoecon Outcomes Res ; 18(2): 177-189, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29400089

RESUMEN

INTRODUCTION: The cost-effectiveness of clinical interventions is often assessed using current care as comparator. However, evidence suggests practice variation in stroke imaging across countries. For the purpose of feeding into cost-effectiveness analysis, this research aims to describe the patterns of stroke imaging, examine practice variations across countries and, as such, obtain results reflecting current care. AREAS COVERED: A systematic literature review was conducted to identify original studies reporting the imaging workup used in acute stroke care in clinical practice in Hungary, Germany, Sweden and the UK. Information regarding the type and frequency of stroke imaging was analysed. Computed Tomography (CT) was reported as the main diagnostic imaging modality used in stroke care (78-98% across patient profiles and time periods). This review revealed patterns that were not observed in individual studies. Comparisons of UK studies revealed considerable variations in the proportion of scanned patients and timing of imaging. EXPERT COMMENTARY: While the evidence about thrombectomy is difficult to translate in clinical practice, the evidence regarding the optimal imaging approach to diagnose stroke patients is lacking. The heterogeneity in stroke imaging reinforces the need to compare the quality of stroke care within and between countries.


Asunto(s)
Accidente Cerebrovascular/diagnóstico por imagen , Trombectomía/métodos , Tomografía Computarizada por Rayos X/métodos , Análisis Costo-Beneficio , Atención a la Salud/normas , Atención a la Salud/estadística & datos numéricos , Europa (Continente) , Humanos , Calidad de la Atención de Salud , Accidente Cerebrovascular/cirugía , Factores de Tiempo
13.
Eur Radiol ; 28(2): 770-779, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28856413

RESUMEN

OBJECTIVES: To evaluate the diagnostic performance of brain CT images reconstructed with a model-based iterative algorithm performed at usual and reduced dose. METHODS: 115 patients with histologically proven lung cancer were prospectively included over 15 months. Patients underwent two CT acquisitions at the initial staging, performed on a 256-slice MDCT, at standard (CTDIvol: 41.4 mGy) and half dose (CTDIvol: 20.7 mGy). Both image datasets were reconstructed with filtered back projection (FBP) and iterative model-based reconstruction (IMR) algorithms. Brain MRI was considered as the reference. Two blinded independent readers analysed the images. RESULTS: Ninety-three patients underwent all examinations. At the standard dose, eight patients presented 17 and 15 lesions on IMR and FBP CT images, respectively. At half-dose, seven patients presented 15 and 13 lesions on IMR and FBP CT images, respectively. The test could not highlight any significant difference between the standard dose IMR and the half-dose FBP techniques (p-value = 0.12). MRI showed 46 metastases on 11 patients. Specificity, negative and positive predictive values were calculated (98.9-100 %, 93.6-94.6 %, 75-100 %, respectively, for all CT techniques). CONCLUSION: No significant difference could be demonstrated between the two CT reconstruction techniques. KEY POINTS: • No significant difference between IMR100 and FBP50 was shown. • Compared to FBP, IMR increased the image quality without diagnostic impairment. • A 50 % dose reduction combined with IMR reconstructions could be achieved. • Brain MRI remains the best tool in lung cancer staging.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/secundario , Neoplasias Pulmonares/patología , Imagen por Resonancia Magnética , Interpretación de Imagen Radiográfica Asistida por Computador , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodos
14.
Ann Surg ; 266(5): 754-764, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28742686

RESUMEN

OBJECTIVE: During the last decade, face allotransplantation has been shown to be a revolutionary reconstructive procedure for severe disfigurements. However, offer to patients remains limited due to lifelong immunosuppression. To move forward in the field, a new pathway in tissue engineering is proposed. BACKGROUND: Our previously reported technique of matrix production of a porcine auricular subunit graft has been translated to a human face model. METHODS: 5 partial and 1 total face grafts were procured from human fresh cadavers. After arterial cannulation, the specimens were perfused using a combined detergent/polar solvent decellularization protocol. Preservation of vascular patency was assessed by imaging, cell and antigen removal by DNA quantification and histology. The main extracellular matrix proteins and associated cytokines were evaluated. Lip scaffolds were cultivated with dermal, muscle progenitor and endothelial cells, either on discs or in a bioreactor. RESULTS: Decellularization was successful in all facial grafts within 12 days revealing acellular scaffolds with full preservation of innate morphology. Imaging demonstrated a preservation of the entire vascular tree patency. Removal of cells and antigens was confirmed by reduction of DNA and antigen markers negativation. Microscopic evaluation revealed preservation of tissue structures as well as of major proteins. Seeded cells were viable and well distributed within all scaffolds. CONCLUSIONS: Complex acellular facial scaffolds were obtained, preserving simultaneously a cell-friendly extracellular matrix and a perfusable vascular tree. This step will enable further engineering of postmortem facial grafts, thereby offering new perspectives in composite tissue allotransplantation.


Asunto(s)
Trasplante Facial , Ingeniería de Tejidos/métodos , Biomarcadores/metabolismo , Reactores Biológicos , Citocinas/metabolismo , Matriz Extracelular/metabolismo , Humanos , Inmunohistoquímica , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Perfusión/métodos , Reperfusión/métodos , Andamios del Tejido
15.
Eur Radiol ; 27(3): 927-937, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27300195

RESUMEN

OBJECTIVES: To compare image quality [low contrast (LC) detectability, noise, contrast-to-noise (CNR) and spatial resolution (SR)] of MDCT images reconstructed with an iterative reconstruction (IR) algorithm and a filtered back projection (FBP) algorithm. METHODS: The experimental study was performed on a 256-slice MDCT. LC detectability, noise, CNR and SR were measured on a Catphan phantom scanned with decreasing doses (48.8 down to 0.7 mGy) and parameters typical of a chest CT examination. Images were reconstructed with FBP and a model-based IR algorithm. Additionally, human chest cadavers were scanned and reconstructed using the same technical parameters. Images were analyzed to illustrate the phantom results. RESULTS: LC detectability and noise were statistically significantly different between the techniques, supporting model-based IR algorithm (p < 0.0001). At low doses, the noise in FBP images only enabled SR measurements of high contrast objects. The superior CNR of model-based IR algorithm enabled lower dose measurements, which showed that SR was dose and contrast dependent. Cadaver images reconstructed with model-based IR illustrated that visibility and delineation of anatomical structure edges could be deteriorated at low doses. CONCLUSION: Model-based IR improved LC detectability and enabled dose reduction. At low dose, SR became dose and contrast dependent. KEY POINTS: • Model- based Iterative Reconstruction improves detectability of low contrast object. • With model- based Iterative Reconstruction, spatial resolution is dose and contrast dependent. • Model-based Iterative Reconstruction algorithms enable improved IQ combined with dose-reduction possibilities. • Improvement of SR and LC detectability on the same IMR data set would reduce reconstructions.


Asunto(s)
Tomografía Computarizada Multidetector/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/métodos , Algoritmos , Cadáver , Humanos , Fantasmas de Imagen , Dosis de Radiación , Reproducibilidad de los Resultados , Tórax/diagnóstico por imagen
16.
COPD ; 12(1): 38-45, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24914492

RESUMEN

UNLABELLED: Abstract Objective: To describe CT features associated with severe exacerbations of Chronic Obstructive Pulmonary Disease (COPD). MATERIALS AND METHODS: In this prospective ethical-committee-approved study, 44 COPD patients (34 men, 10 women, age range 49-83 years) who provided written informed consent were included at the time of hospital admission for severe exacerbation. Pulmonary function tests (PFT) and chest CT scans were performed at admission and after resolution of the episode following a minimum of 4 weeks free of any acute symptom. For each CT scan, two radiologists independently scored 15 features in each lobe and side. CT features and PFT results were compared for exacerbation and control through Mac-Nemar tests and paired t-tests, respectively. RESULTS: Forced expiratory volume in 1 second and vital capacity improved significantly after exacerbation (p = 0.023 and 0.012, respectively). Bronchial wall thickening and lymphadenopathy were graded significantly higher at exacerbation than at control by both readers (p ranging from < 0.001 to 0.028). Other CT features were not observed during exacerbation, or were so only by one reader (p ranging from < 0.001 to 0.928). CONCLUSION: Only lymphadenopathy and bronchial wall thickening are CT features associated with severe COPD exacerbation, respectively in 25% and 50% of patients. Our findings do not advocate a role for CT in the routine work-up of patients with severe COPD exacerbation.


Asunto(s)
Pulmón/diagnóstico por imagen , Tomografía Computarizada Multidetector , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Femenino , Volumen Espiratorio Forzado , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Índice de Severidad de la Enfermedad , Método Simple Ciego , Capacidad Vital
19.
Eur J Cardiothorac Surg ; 44(1): e32-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23509232

RESUMEN

OBJECTIVES: Because of the limited availability of pulmonary homografts (PH), porcine stentless xenografts (SX) have been proposed as an alternative for pulmonary valve replacement in the Ross operation. However, it is unknown whether they have similar good long-term durability. Therefore, we compared mid- to long-term outcomes between those two right ventricular outflow tract (RVOT) substitutes. METHODS: In 288 adults (>18 years) undergoing a Ross operation between 1991 and 2012, Freestyle(®) SX was used in 18 patients and a cryopreserved PH was used in 270 for RVOT reconstruction. Only patients with follow-up >2 years were included. According to the operative period, gender and age, 37 patients with PH could be matched with 17 SX patients. Clinical and echocardiographic follow-up were obtained. In a subset of patients (SX, n = 11 and PH, n = 25), a cardiac computed tomographic (CT) scan was performed to analyse graft calcification. RESULTS: The mean follow-up period was 8.2 ± 4.0 (range 2-14.6 years). During this period, 3 patients died from cancer, 2 in the SX group and 1 in the PH group (P = 0.15). No patient needed RVOT reoperation. At follow-up, RVOT peak gradient was 21 ± 5.9 mmHg in the SX and 16.3 ± 8.7 in the PH groups (P = 0.07). Peak gradient >40 mmHg was observed in only 1 patient in the PH group. Mean RVOT regurgitation was 0.1 ± 0.4 in the SX group and 0.8 ± 0.6 in the PH group (P = 0.008). CT scan analyses showed progressive calcification mainly of the graft wall, while the valve remained relatively free of calcium. Patients with the SX presented significantly higher calcium scores than those with PH (P = 0.01). CONCLUSIONS: In adult patients having the Ross operation, calcic degeneration is observed in both the PH and the SX used as pulmonary substitutes. Calcification progresses more rapidly in the SX compared with the PH. In both grafts, calcifications affect mainly the wall, while the valve remains relatively free of calcium. As a consequence, both grafts show good and similar haemodynamic outcomes at mid- to long-term follow-up. The Freestyle(®) SX can be considered as an acceptable alternative for RVOT reconstruction when PH is not available.


Asunto(s)
Cardiopatías Congénitas , Enfermedades de las Válvulas Cardíacas , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Xenoinjertos/trasplante , Válvula Pulmonar/trasplante , Adulto , Animales , Válvula Aórtica/cirugía , Enfermedad de la Válvula Aórtica Bicúspide , Estudios de Cohortes , Femenino , Tomografía Computarizada Cuatridimensional , Cardiopatías Congénitas/epidemiología , Cardiopatías Congénitas/cirugía , Enfermedades de las Válvulas Cardíacas/epidemiología , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Implantación de Prótesis de Válvulas Cardíacas/métodos , Ventrículos Cardíacos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Stents , Porcinos , Resultado del Tratamiento
20.
J Cardiovasc Comput Tomogr ; 7(1): 58-61, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23333185

RESUMEN

Recent articles have advocated the possibility of obtaining Agatston coronary calcium scoring at 100 kVp by using a single adapted elevated calcium threshold. To evaluate the influence of kilovoltage potential protocols on the Agatston score, we acquired successive scans of a calcium scoring phantom at 4 levels of kilovoltage potential (80, 100, 120, and 140 kVp, 55 mAs) and measured semiautomatically the individual and the total Agatston score of 6 inserts (of 5-mm and 3-mm diameter) containing hydroxyapatite at different concentrations (800, 400, 200 mg/cm(3)). Our results showed that Agatston scores obtained at various low-kilovoltage potential protocols can be highly overestimated in some particular cases. At 80 kVp, for example, mean measured Agatston score was multiplied by a factor from 1.06 (5-mm highest density insert) to 2.67 (3-mm lowest density insert) compared with the Agatston scores performed at 120 kVp. Indeed in the one hand, reducing kilovoltage potential in multidetector CT acquisitions increase the CT density of coronary calcifications that can be measured on the reconstructed images. On the other hand, Agatston score is a multi-threshold measurement (with a step weighting function). Consequently low kilovoltage potential can lead to overweight some calcifications scores. For these reasons, Agatston score with low kilovoltage potential acquisition cannot be reliably adapted by a unique recalibration of the standard calcium attenuation threshold of 130 HU and requires a standardized CT acquisition protocol at 120 kVp. Alternatives to performing low-dose coronary artery calcium scans are either using coronary calcium scans with reduced tube current (low mAs) at 120 kVp with the iterative reconstructions or using mass/volume scoring (not influenced by kilovoltage potential variations). Finally, we emphasized that incorrect Agatston score evaluation may have important clinical, financial, and health care implications.


Asunto(s)
Artefactos , Calcinosis/diagnóstico por imagen , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Calcinosis/complicaciones , Angiografía Coronaria/instrumentación , Enfermedad de la Arteria Coronaria/etiología , Humanos , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/instrumentación
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