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1.
Clin Radiol ; 76(11): 863.e11-863.e17, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34120733

RESUMO

AIM: To define reference values for the transverse relaxation rate (R2∗) in iron storage organs and to investigate the role of human haemochromatosis protein (HFE) genotype on iron storage. MATERIALS AND METHODS: Whole-body magnetic resonance imaging (MRI) including a five-echo gradient-echo sequence was performed in 483 volunteers (269 men, mean age 59.3 ± 12.2 years) without clinical evidence of an iron storage disease at 1.5 T. R2∗ values were assessed for liver, spleen, pancreas, heart, bones, and brain parenchyma. The HFE genotype was determined regarding the single nucleotide polymorphisms (SNPs) rs74315324, rs1799945, rs41303501, rs1800562, rs1800730. R2∗ values were compared among participants without and with at least one mutation. R2∗ reference values were defined using volunteers without any mutation. RESULTS: Three hundred and one participants had no mutations in any HFE SNP, 182 had at least one mutation. HFE gene mutations were distributed as (heterozygous/homozygous) rs1799945:132/9, rs1800562:33/1, and rs1800730:11/0. Mean R2∗ values ± SD (per second) in the group without mutation were: liver: 33.4 ± 12.7, spleen: 24.1 ± 13.8, pancreas: 27.2 ± 6.6, heart: 32.7 ± 11.8, bone: 69.3 ± 21.0, brain parenchyma: 13.9 ± 1.2. No significant difference in R2∗ values were found between participants with and without the HFE gene mutation for any examined iron storage organ (pliver=0.09, pspleen=0.36, ppancreas = 0.08, pheart = 0.36, pbone = 0.98, pbrain=0.74). CONCLUSION: Reference values of R2∗ in iron storage organs are feasible to support the diagnosis of iron storage diseases. Non-specific mutations in HFE SNPs appear not to affect the phenotype of tissue iron accumulation.


Assuntos
Proteína da Hemocromatose/genética , Hemocromatose/diagnóstico , Ferro/metabolismo , Imageamento por Ressonância Magnética/métodos , Polimorfismo de Nucleotídeo Único/genética , Imagem Corporal Total/métodos , Estudos de Coortes , Feminino , Genótipo , Alemanha , Hemocromatose/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência
2.
Eur Radiol ; 30(11): 5923-5932, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32556463

RESUMO

OBJECTIVES: To reveal the utility of motion artifact reduction with convolutional neural network (MARC) in gadoxetate disodium-enhanced multi-arterial phase MRI of the liver. METHODS: This retrospective study included 192 patients (131 men, 68.7 ± 10.3 years) receiving gadoxetate disodium-enhanced liver MRI in 2017. Datasets were submitted to a newly developed filter (MARC), consisting of 7 convolutional layers, and trained on 14,190 cropped images generated from abdominal MR images. Motion artifact for training was simulated by adding periodic k-space domain noise to the images. Original and filtered images of pre-contrast and 6 arterial phases (7 image sets per patient resulting in 1344 sets in total) were evaluated regarding motion artifacts on a 4-point scale. Lesion conspicuity in original and filtered images was ranked by side-by-side comparison. RESULTS: Of the 1344 original image sets, motion artifact score was 2 in 597, 3 in 165, and 4 in 54 sets. MARC significantly improved image quality over all phases showing an average motion artifact score of 1.97 ± 0.72 compared to 2.53 ± 0.71 in original MR images (p < 0.001). MARC improved motion scores from 2 to 1 in 177/596 (29.65%), from 3 to 2 in 119/165 (72.12%), and from 4 to 3 in 34/54 sets (62.96%). Lesion conspicuity was significantly improved (p < 0.001) without removing anatomical details. CONCLUSIONS: Motion artifacts and lesion conspicuity of gadoxetate disodium-enhanced arterial phase liver MRI were significantly improved by the MARC filter, especially in cases with substantial artifacts. This method can be of high clinical value in subjects with failing breath-hold in the scan. KEY POINTS: • This study presents a newly developed deep learning-based filter for artifact reduction using convolutional neural network (motion artifact reduction with convolutional neural network, MARC). • MARC significantly improved MR image quality after gadoxetate disodium administration by reducing motion artifacts, especially in cases with severely degraded images. • Postprocessing with MARC led to better lesion conspicuity without removing anatomical details.


Assuntos
Artefatos , Aprendizado Profundo , Gadolínio DTPA/farmacologia , Neoplasias Hepáticas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Adulto , Idoso , Idoso de 80 Anos ou mais , Suspensão da Respiração , Meios de Contraste/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Clin Radiol ; 74(7): 539-546, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30955836

RESUMO

AIM: To investigate the accuracy of ultrasonography in the assessment of hepatic steatosis using magnetic resonance imaging (MRI) as standard of reference and to explore the influence of additional hepatic iron overload. MATERIAL AND METHODS: A total of 2,783 volunteers (1,442 women, 1,341 men; mean age, 52.3±13.8 years) underwent confounder-corrected chemical-shift-encoded MRI of the liver at 1.5 T. Proton-density fat fraction (PDFF) and transverse relaxation rate (R2*) were calculated to estimate hepatic steatosis and liver iron overload, respectively. In addition, the presence of hepatic steatosis was assessed by B-mode ultrasonography. The sensitivity, specificity, and accuracy of hepatic ultrasonography were determined for different degrees of hepatic steatosis and different amounts of liver iron. RESULTS: MRI revealed hepatic steatosis in 40% of participants (n=1,112), which was mild in 68.9% (n=766), moderate in 26.7% (n=297), and severe in 4.4% (n=49) of patients. Ultrasonography detected hepatic steatosis in 37.8% (n=1,052), corresponding to 74.5% sensitivity and 86.6% specificity. The sensitivity of ultrasound increased with the amount of hepatic fat present and was 65.1%, 95%, and 96% for low, moderate, and high fat content; whereas the specificity was constantly high at 86.6%. The diagnostic accuracy of ultrasound for detection of hepatic steatosis did not vary significantly with the amount of liver iron present. CONCLUSION: Ultrasonography is an excellent tool to assess hepatic steatosis in the clinical setting with some limitations in patients with a low liver fat content. The detection of hepatic steatosis by ultrasonography is not influenced by liver iron.


Assuntos
Fígado Gorduroso/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Ultrassonografia/métodos , Feminino , Humanos , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
Radiologe ; 59(4): 342-347, 2019 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-30806733

RESUMO

CLINICAL ISSUE: Percutaneous transhepatic biliary and gall bladder interventions play an important role in the diagnosis and therapy of biliary tract diseases. PERFORMANCE: With technical success rates up to 99% as well as complications rates up to a maximum of 26% they showed good results. Indications were opacification of the biliary tree as well as treatment of biliary system pathologies, such as drainage and stents. ACHIEVEMENTS: Interventions were used if endoscopic approaches are not possible or exploited. We describe the current state of knowledge and the range for percutaneous biliary/gall bladder interventions and give an overview of technical approaches for fundamental interventional procedures, including percutaneous transhepatic biliary drainage. PRACTICAL RECOMMENDATIONS: Percutaneous transhepatic biliary and gall bladder interventions are safe and effective treatments for benign and malignant stenosis, postoperative complications and risk patients with cholecystitis.


Assuntos
Drenagem , Vesícula Biliar , Constrição Patológica , Humanos , Complicações Pós-Operatórias , Stents
5.
Int J Obes (Lond) ; 42(2): 183-189, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28925406

RESUMO

BACKGROUND: Various fat depots including visceral (VAT), subcutaneous adipose tissue (SAT) or liver fat content (LFC) were supposed to have different influences on various entities including adipokine levels as well as insulin resistance/sensitivity. Therefore, the aim of the study was to investigate the associations of SAT, VAT and LFC with the levels of leptin and vaspin as well as insulin resistance in a general non-diabetic population. METHODS: In total, 1825 participants of the Study of Health in Pomerania were characterized according to body fat compartments and LFC determined by magnetic resonance imaging. Of those subjects, insulin resistance (HOMA-IR) and insulin sensitivity ([ISI(comp)) were determined in 981 participants and adipokines were assessed in 698 using enzyme-linked immunosorbent assay. Analyses of variance and linear regression models adjusted for age, sex, smoking, height, physical inactivity and alcohol consumption were used for analysis. RESULTS: Using the residual method to assess independently the effect of the various fat depots, a strong positive association of SAT (beta per standard deviation (s.d.) increase 0.54 (95% confidence interval (CI) 0.47-0.60)) but not VAT (beta 0.01 (95% CI -0.08 to 0.09)) and LFC (beta 0.01 (95% CI -0.06 to 0.08)) with log2-leptin levels was found independent of the HOMA-IR status. Moreover, a positive association of LFC (beta 0.17 (95% CI 0.07-0.26)) with log2-vaspin levels becomes apparent, which were mostly driven by subjects with a low HOMA-IR. With respect to HOMA-IR and ISI(comp) index, pronounced positive and inverse associations to all fat markers were revealed, respectively, with the strongest relation found for SAT and LFC. CONCLUSIONS: SAT and LFC were identified as predominant sites associated with leptin and vaspin levels, respectively. Residual analysis pointed towards a general adverse effect of disproportional triglyceride storage across physiological despots, in particular in ectopic sides such as the liver, with markers of insulin resistance.


Assuntos
Resistência à Insulina/fisiologia , Leptina/metabolismo , Serpinas/metabolismo , Gordura Subcutânea/metabolismo , Adulto , Distribuição por Idade , Idoso , Consumo de Bebidas Alcoólicas/epidemiologia , Biomarcadores/metabolismo , Índice de Massa Corporal , Ensaio de Imunoadsorção Enzimática , Feminino , Alemanha/epidemiologia , Inquéritos Epidemiológicos , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo , Fígado/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Comportamento Sedentário , Distribuição por Sexo , Fumar/epidemiologia , Gordura Subcutânea/diagnóstico por imagem , Adulto Jovem
6.
Eur J Clin Microbiol Infect Dis ; 36(2): 373-378, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27778120

RESUMO

To establish a routine workflow for in vivo magnetic resonance imaging (MRI) of mice infected with bacterial biosafety level 2 pathogens and to generate a mouse model for systemic infection with Staphylococcus aureus suitable for monitoring by MRI. A self-contained acrylic glass animal bed complying with biosafety level 2 requirements was constructed. After intravenous infection with 105 colony-forming units (CFU) (n = 3), 106 CFU (n = 11) or 107 CFU (n = 6) of S. aureus strain Newman, female Balb/c mice were whole-body scanned by 7T MRI. Abdominal infections such as abscesses were visualized using a standard T2-weighted scan. Infection monitoring was performed for each animal by measurements at 1, 3, and 7 days after infection. Intravenous pathogen application led to a dose-dependent decrease in survival probability (p = 0.03). In the group with the highest infectious dose the 7-day survival rate was 33 %. An intermediate S. aureus dose showed a survival rate of 80 %, whereas at the lowest infection dose, none of the animals died. All animals with the highest infection dose exhibited hepatic abscesses 4 days after inoculation, 80 % developed renal abscesses on the 3rd day. Mice obtaining the intermediate S. aureus load reached a plateau at day 4 with 72 % liver and 60 % renal abscess probability. No abscesses were observed in other abdominal organs at any time point. The implemented experimental setup provides a suitable and reliable in vivo MRI method to study murine abdominal infection models using BSL-2 pathogen. Systemic Staphylococcus aureus infection leads to a dose-dependent development of hepatic and renal abscesses.


Assuntos
Abscesso Abdominal/diagnóstico por imagem , Modelos Animais de Doenças , Nefropatias/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Infecções Estafilocócicas/diagnóstico por imagem , Abscesso Abdominal/patologia , Animais , Carga Bacteriana , Feminino , Nefropatias/patologia , Hepatopatias/patologia , Camundongos Endogâmicos BALB C , Infecções Estafilocócicas/patologia , Staphylococcus aureus/isolamento & purificação , Análise de Sobrevida
8.
Radiologe ; 55(4): 308-13, 2015 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-25802035

RESUMO

CLINICAL/METHODICAL ISSUE: Fatty liver disease plays an important role in the development of type 2 diabetes. Accurate techniques for detection and quantification of liver fat are essential for clinical diagnostics. STANDARD RADIOLOGICAL METHODS: Chemical shift-encoded magnetic resonance imaging (MRI) is a simple approach to quantify liver fat content. METHODICAL INNOVATIONS: Liver fat quantification using chemical shift-encoded MRI is influenced by several bias factors, such as T2* decay, T1 recovery and the multispectral complexity of fat. PERFORMANCE: The confounder corrected proton density fat fraction is a simple approach to quantify liver fat with comparable results independent of the software and hardware used. ACHIEVEMENTS: The proton density fat fraction is an accurate biomarker for assessment of liver fat. PRACTICAL RECOMMENDATIONS: An accurate and reproducible quantification of liver fat using chemical shift-encoded MRI requires a calculation of the proton density fat fraction.


Assuntos
Tecido Adiposo/patologia , Complicações do Diabetes/patologia , Fígado Gorduroso/patologia , Interpretação de Imagem Assistida por Computador/métodos , Fígado/patologia , Alemanha , Humanos , Interpretação de Imagem Assistida por Computador/normas , Medição de Risco/métodos
9.
Clin Radiol ; 69(10): 1027-33, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24957855

RESUMO

AIM: To investigate the feasibility of gadoxetate disodium-enhanced magnetic resonance (MR) cholangiography in chronic obstructive cholestatic biliary disease in the clinical setting. MATERIALS AND METHODS: Twenty-three patients with dilated bile duct trees and ten volunteers underwent gadoxetate disodium-enhanced liver MR cholangiography and were enrolled in the present retrospective study. Gadoxetate disodium was given in a standardized manner as a bolus injection at a dose of 0.25 mmol/kg of body weight (0.1 ml/kg). Region of interest-based measurement of mean enhancement of the dilated bile ducts was performed in series before gadoxetate disodium administration and during hepatobiliary phases. RESULTS: Direct comparison of mean bile duct enhancement during hepatobiliary phases in the clinical imaging window between healthy volunteers [4.7 ± 2.2 arbitrary units (au)] and patients with dilated bile ducts (0.1 ± 0.3 au) revealed significantly lower or absent enhancement in dilated bile ducts (p = 0.001). CONCLUSION: Standard clinical gadoxetate disodium-enhanced MR cholangiography is not a reliable technique for the evaluation of the biliary trees, because of altered biliary gadoxetate disodium elimination in patients with chronic obstructive biliary diseases.


Assuntos
Doenças dos Ductos Biliares/diagnóstico , Colangiografia/métodos , Meios de Contraste , Gadolínio DTPA , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Ductos Biliares/patologia , Colestase/diagnóstico , Doença Crônica , Estudos de Viabilidade , Feminino , Humanos , Masculino , Estudos Retrospectivos
10.
Pneumologie ; 67(10): 573-9, 2013 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-23999695

RESUMO

BACKGROUND: Superior vena cava syndrome is defined as the lack of central venous inflow through the superior vena cava and can present a life-threatening situation. The acute situation is characterized by dyspnea and requires a fast and effective treatment. METHODS: Using two case reports, endovascular stent therapy for the treatment of acute and subacute superior vena cava syndrome is explained and discussed. RESULTS: In the first case, we introduce a patient with acute dyspnea due to decompensation of a chronic thrombosis of the superior vena cava. The second case displayed the same acute symptoms consisting of acute dyspnea and upper venous congestion due to a tumor-related compression of the superior vena cava. In both cases, the acute situation of superior vena cava syndrome was successfully treated by stent implantation. CONCLUSION: Endovascular treatment of superior vena cava syndrome is an effective option with a high technical success rate.


Assuntos
Prótese Vascular , Dispneia/etiologia , Dispneia/prevenção & controle , Procedimentos Endovasculares/métodos , Stents , Síndrome da Veia Cava Superior/diagnóstico , Síndrome da Veia Cava Superior/cirurgia , Doença Aguda , Idoso , Dispneia/diagnóstico , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
12.
Sci Rep ; 13(1): 10164, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349374

RESUMO

To evaluate the influence of the blood-brain barrier on neuronal gadolinium deposition in a mouse model after multiple intravenous applications of the linear contrast agent gadodiamide. The prospective study held 54 mice divided into three groups: healthy mice (A), mice with iatrogenic induced disturbance of the blood-brain barrier by glioblastoma (B) or cerebral infarction (C). In each group 9 animals received 10 iv-injections of gadodiamide (1.2 mmol/kg) every 48 h followed by plain T1-weighted brain MRI. A final MRI was performed 5 days after the last contrast injection. Remaining mice underwent MRI in the same time intervals without contrast application (control group). Signal intensities of thalamus, pallidum, pons, dentate nucleus, and globus pallidus-to-thalamus and dentate nucleus-to-pons ratios, were determined. Gadodiamide complex and total gadolinium amount were quantified after the last MR examination via LC-MS/MS and ICP-MS. Dentate nucleus-to-pons and globus pallidus-to-thalamus SI ratios showed no significant increase over time within all mice groups receiving gadodiamide, as well as compared to the control groups at last MR examination. Comparing healthy mice with group B and C after repetitive contrast administration, a significant SI increase could only be detected for glioblastoma mice in globus pallidus-to-thalamus ratio (p = 0.033), infarction mice showed no significant SI alteration. Tissue analysis revealed significantly higher gadolinium levels in glioblastoma group compared to healthy (p = 0.013) and infarction mice (p = 0.029). Multiple application of the linear contrast agent gadodiamide leads to cerebral gadolinium deposition without imaging correlate in MRI.


Assuntos
Glioblastoma , Compostos Organometálicos , Camundongos , Animais , Meios de Contraste/farmacologia , Barreira Hematoencefálica/diagnóstico por imagem , Gadolínio/farmacologia , Cromatografia Líquida , Estudos Prospectivos , Estudos Retrospectivos , Espectrometria de Massas em Tandem , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Globo Pálido , Modelos Animais de Doenças
13.
Sci Rep ; 12(1): 1257, 2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-35075169

RESUMO

To investigate the accuracy of liver diameters for estimation of liver size and to evaluate their application as tool for assessment of parenchymal liver disease. In the course of a population-based study, (SHIP) one thousand nine hundred thirty-nine volunteers underwent magnetic resonance imaging (MRI) of the liver including 3D gradient echo MRI sequences. Maximum liver diameters were measured in cranio-caudal (CC), anterior-posterior (AP), medial-lateral (ML) orientation. Diameters were compared with true liver volume assessed by liver segmentation. Additionally, age-dependent reference values for diameters were defined. Finally, accuracy of liver diameters was assessed to discriminate volunteers with healthy livers and participants with parenchymal changes, measured by MRI and laboratory. Reference values of liver diameters within the healthy population (n = 886) were defined as follows (mean ± standard deviation, confidence interval CI in cm): CC 17.2 ± 2, CI 13.6/21.2; AP 15.8 ± 1.9, CI 12.6/19.8; ML 19.7 ± 2.3, CI 15.8/24.6. There was a poor correlation using linear regression between liver diameter and true liver volume; CC 0.393, AP 0.359; ML 0.137. The AP direction shows the best correlation to discriminate between healthy and pathologic liver changes; AUC 0.78; p < 0.001, CC AUC 0.53; p < 0.001 and ML AUC 0.52; p = 0.008. Measurement of liver diameter, especially in the anterior-posterior direction is a simple option to detect chronic liver disease but less suitable for prediction of liver volume.


Assuntos
Fígado/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Hepatopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Valores de Referência , Adulto Jovem
14.
Sci Rep ; 12(1): 12465, 2022 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-35864140

RESUMO

To evaluate the suitability of volume index measurement (VI) by either ultrasound (US) or computed tomography (CT) for the assessment of liver volume. Fifty-nine patients, 21 women, with a mean age of 66.8 ± 12.6 years underwent US of the liver followed immediately by abdominal CT. In US and CT imaging dorsoventral, mediolateral and craniocaudal liver diameters in their maximum extensions were assessed by two observers. VI was calculated by multiplication of the diameters divided by a constant (3.6). The liver volume determined by a manual segmentation in CT ("true liver volume") served as gold standard. True liver volume and calculated VI determined by US and CT were compared using Bland-Altman analysis. Mean differences of VI between observers were - 34.7% (- 90.1%; 20.7%) for the US-based and 1.1% (- 16.1%; 18.2%) for the CT-based technique, respectively. Liver volumes determined by semi-automated segmentation, US-based VI and CT-based VI, were as follows: 1.500 ± 347cm3; 863 ± 371cm3; 1.509 ± 432cm3. Results showed a great discrepancy between US-based VI and true liver volume with a mean bias of 58.3 ± 66.9%, and high agreement between CT-based VI and true liver volume with a low mean difference of 4.4 ± 28.3%. Volume index based on CT diameters is a reliable, fast and simple approach for estimating liver volume and can therefore be recommended for clinical practice. The usage of US-based volume index for assessment of liver volume should not be used due to its low accuracy of US in measurement of liver diameters.


Assuntos
Fígado , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Fígado/diagnóstico por imagem , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia
15.
Sci Rep ; 11(1): 11661, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083637

RESUMO

Aim of this study was to investigate frequency, incidence and risk factors of liver cysts in the general population in a longitudinal survey. Cyst frequency was investigated in 607 adult volunteers (288 women, 319 men, mean age 55 years) using strong T2-weighted magnetic resonance imaging. Risk factors were investigated for occurrence, frequency and size of cystic lesions at baseline. Incidence and physiological growing of the lesions were observed in a 5-years follow-up. At baseline, 431 volunteers had 1,479 cysts (71.0%). The mean number of cysts per person was 3.4 ± 9.0. The mean size of cysts was 13.1 ± 11.7 mm. Women had a higher number of cysts than men (p = 0.026). Older and male volunteers demonstrated a higher cyst frequency (p = 0.002 and p = 0.025). Per one-year increase in age the chance for a liver cyst increased by 2%. Four-hundred seventeen volunteers had cysts in the follow-up, in 24.6% new lesions had occurred. Lesion size significantly increased in follow-up (p < 0.001). Age and male sex were associated with the occurrence of at least one liver cyst. Women had a higher average number of cysts. Cystic lesion progression is a physiological phenomenon in the long-term follow-up.


Assuntos
Cistos/epidemiologia , Neoplasias Hepáticas/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Cistos/diagnóstico por imagem , Cistos/patologia , Feminino , Seguimentos , Humanos , Incidência , Achados Incidentais , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Fatores de Risco , Adulto Jovem
16.
Int J Cardiovasc Imaging ; 35(7): 1379-1386, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30850908

RESUMO

New protocols for coronary computed tomography angiography (CCTA) could lower the radiation dose for patients but influence the image quality. To compare image quality and radiation exposure in step-and-shoot CCTA and high-pitch spiral CCTA. Fifty-nine pairs of patients matched for weight, height, sex and heart rate were included in this study (74 m, 44 f, average age 60 years, age range 29-94 years). Step-and-shoot CCTA and high-pitch spiral CCTA was performed on a third generation dual-source CT in equally sized patient groups. The signal-to-noise ratio (SNR) in the ascending aorta and the coronary arteries were determined for each dataset. Image quality was rated using a five-point scale. We used the t-test for paired samples to compare SNR and effective dose, and the Wilcoxon test to compare image quality scores. Mean effective dose for the step-and-shoot protocol (4.15 ± 3.07 mSv) was significantly higher in comparison to the high-pitch spiral protocol (1.2 ± 0.69 mSv; p < 0.0001). Mean SNR was higher with the step-and-shoot protocol compared to the high-pitch spiral protocol in the aorta, in the left main and peripheral coronary arteries (p < 0.01), in the proximal right coronary artery (p = 0.027). Image quality scores were significantly better for the step-and-shoot protocol (p = 0.0003). Step-and-shoot CCTA has significantly better SNR and overall image quality compared to high-pitch spiral CCTA, but with a mean effective dose more than thrice as high.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Doses de Radiação , Exposição à Radiação , Tomografia Computadorizada Espiral/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Aorta/diagnóstico por imagem , Aortografia/métodos , Angiografia por Tomografia Computadorizada/efeitos adversos , Angiografia Coronária/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Exposição à Radiação/efeitos adversos , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Tomografia Computadorizada Espiral/efeitos adversos
17.
Eur J Radiol ; 106: 32-37, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30150048

RESUMO

PURPOSE: To investigate factors influencing liver size and to determine reference values of liver volume (LV) for healthy subjects. METHODS: 2773 volunteers underwent magnetic resonance imaging (MRI) of the liver in the setting of the population based Study of Health in Pomerania. Based on measurement of maximum diameters in three orientations, LVs were calculated and correlated with demographic factors such as age, gender, and body mass index. In addition, LVs of healthy volunteers and participants with parenchymal liver diseases such as fatty liver disease, iron overload, fibrosis/cirrhosis were compared. Adjusted reference values of liver volumes were defined for the group of healthy participants. RESULTS: In general, mean LV (mean ±â€¯standard deviation) was 1505 ±â€¯385 cm3. Age, gender and body mass index correlated significantly with the liver volume (p ≤ 0.001). Parenchymal liver diseases significantly influence LV (with: 1624 ±â€¯420 cm3, n = 1525 and without parenchymal liver diseases: 1360 ±â€¯273 cm3; n = 1.248, p ≤ 0.001). Compared to LV of participants without liver diseases, LV was increased in volunteers with hepatic steatosis (1717 ±â€¯419 cm3; n = 1111), liver iron overload (1558 ±â€¯367 cm3; n = 553; p ≤ 0.001) as well as in participants with fibrosis/cirrhosis (1494 ±â€¯459 cm3; n = 383). CONCLUSIONS: LV is influenced by age, body mass index and parenchymal liver diseases. Reference values were established to aid in the diagnosis of parenchymal liver diseases.


Assuntos
Voluntários Saudáveis , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Tamanho do Órgão/fisiologia , Adulto , Idoso , Índice de Massa Corporal , Fígado Gorduroso , Feminino , Alemanha , Inquéritos Epidemiológicos , Humanos , Fígado/patologia , Cirrose Hepática , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valores de Referência , População Branca
18.
Abdom Radiol (NY) ; 41(7): 1293-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26907711

RESUMO

OBJECTIVES: The purpose of the study was to evaluate the accuracy of measured diameters and calculated volume indices for determining liver size and to derive a simple approach for estimating liver volume. METHODS: Three hundred twenty-nine volunteers (cohort A) were grouped according to liver volume: small (n = 109), medium (n = 110), and large (n = 110). True liver volume was determined by magnetic resonance imaging (MRI) using manual segmentation. Maximum diameters (maxdiam) of the liver and distances in midclavicular line (MCL) were measured. Volume indices were calculated as a simple product of the measured diameters. The calculated volume indices were calibrated to predict true liver volume. Performance of the calibrated method was evaluated in a control group (cohort B) including randomly selected volunteers (n = 110) and a patient group with histopathologically proven parenchymal liver diseases (n = 28). RESULTS: In cohort A, there was strong correlation between diameters and true liver volume (r s = 0.631-0.823). Calculated volume indices had slightly better correlation (maxdiam r s = 0.903, MCL r s = 0.920). A calibration index was calculated from the volumes and diameters determined in cohort A. Application of this calibration on cohort B verified a very strong correlation between calibrated volume indices and true liver volume (maxdiam r s = 0.920, MCL r s = 0.909). In addition, the low mean difference between predicted liver volume (maxdiam = -70.9 cm(3);MCL = -88.4 cm(3)) and true liver volume confirms that the calibrated method allows accurate assessment of liver volume. CONCLUSIONS: Both simple diameters and volume indices allow estimating liver size. A simple calibration formula enables prediction of true liver volume without significant expense.


Assuntos
Fígado/anatomia & histologia , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Algoritmos , Feminino , Alemanha , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Valores de Referência , Estudos Retrospectivos
19.
Medicine (Baltimore) ; 48(6): 411-39, 1969 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-4951233

RESUMO

Forty examples (27 from the literature and 13 new cases) of a syndrome of hypomegakaryocytic thrombocytopenia with bilateral absence of the radius have been analyzed. This syndrome is designated in this paper as "thrombocytopenia with absent radius (TAR)". The onset of hematologic complications usually occurs at birth or during early infancy. Thrombocytopenia may be episodic and sometimes is accompanied by leukemoid reactions and eosinophilia. Bone marrow examination reveals decreased and/or abnormal megakaryocytes, with normal myeloid and erythroid precursors. Congenital skeletal deformities include bilateral absence of radius, shortening and deformity of the ulnae, and occasionally absence of all the long bones in the arm. The fingers and thumbs are always present. Other skeletal anomalies are frequent. Cardiac anomalies, particularly the tetralogy of Fallot and atrial septal defects, may be present. Other non-skeletal congenital abnormalities are rare. The prognosis is good if the patient survives to one year of age. The syndrome has been compared to Fanconi's anemia, thalidomide embryopathy, limb-cardiovascular syndrome, and a syndrome of multiple congenital malformations, from which it can be distinguished.


Assuntos
Anormalidades Múltiplas/genética , Rádio (Anatomia)/anormalidades , Trombocitopenia/genética , Adolescente , Adulto , Contagem de Células , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Cardiopatias Congênitas/genética , Humanos , Lactente , Recém-Nascido , Deformidades Congênitas dos Membros , Masculino , Megacariócitos/patologia , Linhagem , Síndrome , Trombocitopenia/congênito
20.
Pediatrics ; 82(4): 609-14, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3050866

RESUMO

The purpose of the study was to determine the incidence of silent but significant urinary tract abnormalities that might be detected by screening renal ultrasound studies of apparently healthy infants. Of 437 babies studied, six were found to have uropathology severe enough to warrant surgery for an incidence of 1.37% or one of every 73 babies studied.


Assuntos
Ultrassonografia , Sistema Urinário/anormalidades , Feminino , Humanos , Lactente , Masculino , Programas de Rastreamento , New York , Sistema Urinário/cirurgia
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