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1.
Radiologe ; 61(Suppl 1): 49-53, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34013397

RESUMO

BACKGROUND: The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks. OBJECTIVES: The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine. MATERIAL AND METHODS: A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed. RESULTS: The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3. CONCLUSION: Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.


Assuntos
Fáscia , Vértebras Lombares , Fáscia/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética , Músculo Esquelético , Estudos Retrospectivos
2.
Eur Radiol ; 30(1): 1-10, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31278580

RESUMO

OBJECTIVES: Various imaging methods have been evaluated regarding non-invasive differentiation of renal cell carcinoma (RCC) subtypes. Dual-energy computed tomography (DECT) allows iodine concentration (IC) analysis as a correlate of tissue perfusion. Microvascular density (MVD) in histopathology specimens is evaluated to determine intratumoral vascularization. The objective of this study was to assess the potential of IC and MVD regarding the differentiation between papillary and clear cell RCC and between well- and dedifferentiated tumors. Further, we aimed to investigate a possible correlation between these parameters. METHODS: DECT imaging series of 53 patients with clear cell RCC (ccRCC) and 15 with papillary RCC (pRCC) were analyzed regarding IC. Histology samples were stained using CD31/CD34 monoclonal antibodies; MVD was evaluated digitally. Statistical analysis included performance of Mann-Whitney U test, ROC analysis, and Spearman rank correlation. RESULTS: Analysis of IC demonstrated significant differences between ccRCC and pRCC (p < 0.001). A cutoff value of ≤ 3.1 mg/ml at IC analysis allowed identification of pRCC with an accuracy of 86.8%. Within the ccRCC subgroup, G1/G2 tumors could significantly be differentiated from G3/G4 carcinomas (p = 0.045). A significant positive correlation between IC and MVD could be determined for the entire RCC cohort and the ccRCC subgroup. Limitations include the small percentage of pRCCs. CONCLUSIONS: IC analysis is a useful method to differentiate pRCC from ccRCC. The significant positive correlation between IC and MVD indicates valid representation of tumor perfusion by DECT. KEY POINTS: • Analysis of iodine concentration using DECT imaging could reliably distinguish papillary from clear cell subtypes of renal cell cancer (RCC). • A cutoff value of 3.1 mg/ml allowed a distinction between papillary and clear cell RCCs with an accuracy of 86.8%. • The positive correlation with microvascular density in tumor specimens indicates correct display of perfusion by iodine concentration analysis.


Assuntos
Carcinoma Papilar/patologia , Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/irrigação sanguínea , Carcinoma Papilar/diagnóstico por imagem , Carcinoma de Células Renais/irrigação sanguínea , Carcinoma de Células Renais/diagnóstico por imagem , Transformação Celular Neoplásica/patologia , Meios de Contraste/farmacocinética , Feminino , Humanos , Iodo/farmacocinética , Neoplasias Renais/irrigação sanguínea , Neoplasias Renais/diagnóstico por imagem , Masculino , Microvasos/diagnóstico por imagem , Microvasos/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X/métodos , Carga Tumoral
3.
Eur Radiol ; 30(3): 1644-1652, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31802213

RESUMO

Women in Focus: Be Inspired was a unique programme held at the 2019 European Congress of Radiology that was structured to address a range of topics related to gender and healthcare, including leadership, mentoring and the generational progression of women in medicine. In most countries, women constitute substantially fewer than half of radiologists in academia or private practice despite frequently accounting for at least half of medical school enrolees. Furthermore, the proportion of women decreases at higher academic ranks and levels of leadership, a phenomenon which has been referred to as a "leaky pipeline". Gender diversity in the radiologic workplace, including in academic and leadership positions, is important for the present and future success of the field. It is a tool for excellence that helps to optimize patient care and research; moreover, it is essential to overcome the current shortage of radiologists. This article reviews the current state of gender diversity in academic and leadership positions in radiology internationally and explores a wide range of potential reasons for gender disparities, including the lack of role models and mentorship, unconscious bias and generational changes in attitudes about the desirability of leadership positions. Strategies for both individuals and institutions to proactively increase the representation of women in academic and leadership positions are suggested. KEY POINTS: • Gender-diverse teams perform better. Thus, gender diversity throughout the radiologic workplace, including in leadership positions, is important for the current and future success of the field. • Though women now make up roughly half of medical students, they remain underrepresented among radiology trainees, faculty and leaders. • Factors leading to the gender gap in academia and leadership positions in Radiology include a lack of role models and mentors, unconscious biases, other societal barriers and generational changes.


Assuntos
Liderança , Médicas/tendências , Radiologistas/tendências , Radiologia/organização & administração , Feminino , Humanos
4.
Eur Radiol ; 29(3): 1094-1103, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30151643

RESUMO

OBJECTIVES: Diverticular disease represents an increasing pathology and healthcare burden worldwide. Our aim was to study the prevalence, extent and distribution of asymptomatic diverticular disease assessed by magnetic resonance imaging (MRI) in a sample of a Western population. METHODS: Subjects from a population-based cohort study who underwent 3-T MRI were analyzed for the prevalence and extent of diverticula of the colon using an isotropic VIBE-Dixon gradient-echo sequence. The extent of diverticular disease was categorized according to the number of diverticula in each colonic segment. Univariate and adjusted analyses were performed to assess associated characteristics and risk factors. RESULTS: Among 393 subjects included in the analysis (56.4 ± 9.2 years, 57.5% males), 164 (42%) had diverticular disease, with the highest prevalence in the left-sided colonic segments (93% diverticular disease in the descending and sigmoid segment). Subjects with advanced diverticular disease were older (62.1 vs. 54.4 years) and had a higher body mass index (BMI), LDL cholesterol levels and systolic blood pressure (30.2 ± 5.1 vs. 27.8 ± 4.9 kg/m2, 149.8 ± 29.3 vs. 135.2 ± 32.9 mg/dl and 128.2 ± 14.1 vs. 118.4 ± 16.1 mmHg, respectively; all p > 0.003) compared with subjects without diverticular disease. In contrast, no significant correlation could be found for gender, physical activity, smoking status and alcohol consumption (all p > 0.31). Intra-rater reliability was excellent for all colonic segments (intra-class correlation [ICC] = 0.99-1.00), and inter-rater reliability was excellent for left- and right-sided colonic segments (ICC = 0.84-0.97). CONCLUSIONS: These findings provide insights into the disease mechanism of asymptomatic diverticular disease and may help to improve prevention of diverticulosis and its associated complications. KEY POINTS: • Overall prevalence of asymptomatic diverticular disease assessed by MRI was 42%, affecting predominantly the left-sided colon. • Asymptomatic diverticular disease was associated with age and cardiometabolic risk factors. • Magnetic resonance imaging reveals insights into the pathophysiologic mechanism of asymptomatic diverticular disease.


Assuntos
Colo/patologia , Doenças Diverticulares/diagnóstico , Imageamento por Ressonância Magnética/métodos , Idoso , Índice de Massa Corporal , Estudos de Coortes , Doenças Diverticulares/epidemiologia , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Risco
5.
Radiol Med ; 124(9): 926-933, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31175536

RESUMO

PURPOSE: To evaluate the rate and types of complications after minimally invasive radiological central vein port implantation without ultrasound guidance. MATERIALS AND METHODS: We retrospectively evaluated 8654 patients who underwent port implantations in the subclavian vein without ultrasound guidance in our institution from 1998 to 2014 with regard to types and rates of peri-, early and late post-interventional complications according to the common classification for complications published by the Society of Interventional Radiology (SIR). Additionally, the impact of the training level of the operators on the rate of complications was analyzed. RESULTS: Successful port implantations were performed in 99.8% (8636/8654 procedures). From 1998 to 2014, a total of 565 (6.52%) complications were recorded. The overall percentage of the peri-, early and late post-interventional complications according to the SIR criteria was 1.69, 0.15 and 4.68, respectively. Significant differences due to the training level of the performing physician could be seen for the rates of pneumothorax, arterial puncture and hematoma. CONCLUSION: Minimally invasive radiological interventional port implantation is a safe treatment option with a low rate of complications even without ultrasound guidance.


Assuntos
Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos , Cateteres de Demora , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Radiologia Intervencionista , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Estudos Retrospectivos , Veia Subclávia , Ultrassonografia de Intervenção , Adulto Jovem
6.
Radiology ; 288(2): 518-526, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29893641

RESUMO

Purpose To determine the impact of patient age on the cost-effectiveness of endovascular therapy (EVT) in addition to standard care (SC) in large-vessel-occlusion stroke for patients aged 50 to 100 years in the United States. Materials and Methods A decision-analytic Markov model was used to estimate direct and indirect lifetime costs and quality-adjusted life years (QALYs). Age-dependent input parameters were obtained from the literature. Deterministic and probabilistic sensitivity analysis for age at index stroke were used. The willingness-to-pay (WTP) was set to thresholds of $50 000, $100 000, and $150 000 per QALY. The study applied a U.S. setting for health care and societal perspectives. Incremental costs and effectiveness were derived from deterministic and probabilistic sensitivity analysis. Acceptability rates at different WTP thresholds were determined. Results EVT+SC was the dominant strategy in patients aged 50 to 79 years. The highest incremental effectiveness (2.61 QALYs) and cost-savings (health care perspective, $99 555; societal perspective, $146 385) were obtained in 50-year-old patients. In octogenarians (80-89 years), EVT+SC led to incremental QALYs at incremental costs with acceptability rates of more than 85%, more than 99%, and more than 99% at a WTP of $50 000, $100 000, and $150 000 per QALY, respectively. In nonagenarians (90-99 years), acceptability rates at a WTP of $50 000 per QALY dropped but stayed higher than 85% and higher than 95% at thresholds of $100 000 and $150 000 per QALY. Conclusion Using contemporary willingness-to-pay thresholds in the United States, endovascular therapy in addition to standard care reduces lifetime costs for patients up to 79 years of age and is cost-effective for patients aged 80 to 100 years.


Assuntos
Análise Custo-Benefício/economia , Procedimentos Endovasculares/economia , Procedimentos Endovasculares/métodos , Acidente Vascular Cerebral/economia , Acidente Vascular Cerebral/terapia , Isquemia Encefálica/complicações , Isquemia Encefálica/economia , Isquemia Encefálica/terapia , Análise Custo-Benefício/estatística & dados numéricos , Humanos , Acidente Vascular Cerebral/complicações
7.
Eur Radiol ; 28(12): 5284-5292, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29882070

RESUMO

OBJECTIVES: To assess the prognostic value of pre-therapeutic computed tomography (CT) attenuation of liver metastases for overall survival (OS) in metastatic colorectal cancer (mCRC). METHODS: In the open-label, randomised, prospective phase-III FIRE-3 trial, patients with histologically confirmed mCRC received fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) with either cetuximab or bevacizumab. Participating patients gave written informed consent prior to study entry. In CT at baseline (portal venous phase, slice thickness ≤5 mm), mean attenuation [Hounsfield units (HU)] of liver metastases was retrospectively assessed by semi-automated volumetry. Its prognostic influence on OS was analysed in Kaplan-Meier-analysis and Cox proportional hazard regression and an optimal threshold was determined. RESULTS: In FIRE-3, 592 patients were enrolled between 2007 and 2012. Among the 347 patients eligible for liver volumetry, median baseline CT attenuation of liver metastases was 59.67 HU [interquartile range (IQR), 49.13, 68.85]. Increased attenuation was associated with longer OS {per 10 HU: hazard ratio (HR), 0.85 [95% confidence interval (CI), 0.78, 0.93], p < 0.001}. The optimised threshold (≥61.62 HU) was a strong predictor for increased OS [median, 21.3 vs 30.6 months; HR, 0.61 (95% CI, 0.47, 0.80), p < 0.001]. Multivariate regression controlling for correlated and further prognostic factors confirmed this [HR, 0.60 (95% CI, 0.45, 0.81), p = 0.001]. Furthermore, mean attenuation ≥61.62 HU was significantly associated with increased early tumour shrinkage (p = 0.002) and increased depth of response (p = 0.012). CONCLUSIONS: Increased mean baseline CT attenuation of liver metastases may identify mCRC patients with prolonged OS and better tumour response. KEY POINTS: • In colorectal cancer, increased attenuation of liver metastases in baseline computed tomography is a prognostic factor for prolonged OS (p < 0.001). • A threshold of ≥61.62 HU was determined as optimal cut-off to identify patients with prolonged OS (p < 0.001), early tumour shrinkage (p = 0.002) and increased depth of response (p = 0.012).


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/diagnóstico , Neoplasias Hepáticas/secundário , Terapia de Alvo Molecular/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/mortalidade , Feminino , Alemanha/epidemiologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida/tendências
8.
AJR Am J Roentgenol ; 210(6): 1317-1322, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29629804

RESUMO

OBJECTIVE: The aim of this study was to quantitatively assess hyaline cartilage and subchondral bone conditions in a fully preserved cadaveric human knee joint using high-resolution x-ray propagation-based phase-contrast imaging (PBI) CT and to compare the performance of the new technique with conventional CT and MRI. MATERIALS AND METHODS: A cadaveric human knee was examined using an x-ray beam of 60 keV, a detector with a 90-mm2 FOV, and a pixel size of 46 × 46 µm2. PBI CT images were reconstructed with both the filtered back projection algorithm and the equally sloped tomography method. Conventional 3-T MRI and CT were also performed. Measurements of cartilage thickness, cartilage lesions, International Cartilage Repair Society scoring, and detection of subchondral bone changes were evaluated. Visual inspection of the specimen akin to arthroscopy was conducted and served as a standard of reference for lesion detection. RESULTS: Loss of cartilage height was visible on PBI CT and MRI. Quantification of cartilage thickness showed a strong correlation between the two modalities. Cartilage lesions appeared darker than the adjacent cartilage on PBI CT. PBI CT showed similar agreement to MRI for depicting cartilage substance defects or lesions compared with the visual inspection. The assessment of subchondral bone cysts showed moderate to strong agreement between PBI CT and CT. CONCLUSION: In contrast to the standard clinical methods of MRI and CT, PBI CT is able to simultaneously depict cartilage and bony changes at high resolution. Though still an experimental technique, PBI CT is a promising high-resolution imaging method to evaluate comprehensive changes of osteoarthritic disease in a clinical setting.


Assuntos
Doenças das Cartilagens/diagnóstico por imagem , Cartilagem Articular/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Algoritmos , Cadáver , Doenças das Cartilagens/patologia , Cartilagem Articular/patologia , Humanos , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X/métodos
9.
Radiol Med ; 123(6): 456-462, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29380261

RESUMO

BACKGROUND: Intracranial arterial calcifications (ICAC) are often detected on unenhanced CT of patients with an age > 60. However, association with the subsequent occurrence of major adverse cardiovascular events (MACE) has not yet been evaluated. PURPOSE: This study aimed at evaluating the association of ICAC with subsequent MACE and overall mortality. METHODS: In this retrospective, IRB approved study, we included 175 consecutive patients (89 males, mean age 78.3 ± 8.5 years) of age > 60 years who underwent an unenhanced CT of the head due to minor trauma or neurological disorders. Presence of ICAC was determined in seven intracranial arteries using a semi-quantitative scale, which resulted in the calcified plaque score (CPS). Clinical follow-up information was obtained by questionnaires and telephone interviews. MACE was defined as myocardial infarction or revascularization, stroke or death due to cardiovascular event. RESULTS: Mean follow-up time was 39.8 ± 7.8 months, resulting in 579.7 patient-years of follow-up. Overall, 36 MACE occurred during follow-up (annual event rate = 6.2%/year). Mean CPS was significantly higher in subjects with MACE during follow-up compared to subjects without MACE (p < 0.01). In 15 patients CPS was 0; in none of these patients MACE was registered. Kaplan-Meier-analysis revealed that patients with a low plaque burden (CPS < 5) had a significant longer MACE-free and overall survival than patients with a high plaque burden (CPS ≥ 5) (p < 0.01). CONCLUSION: Patients with ICAC have an increased risk for future cardio- or cerebrovascular events. Therefore, ICAC might be a prognostic factor to determine the risk for these events in older patients.


Assuntos
Doenças Cardiovasculares/etiologia , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Calcificação Vascular/complicações , Calcificação Vascular/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/mortalidade , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Inquéritos e Questionários , Taxa de Sobrevida , Calcificação Vascular/mortalidade
10.
Radiology ; 283(2): 478-485, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27905865

RESUMO

Purpose To prospectively evaluate the perfusion patterns at quantitative dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging of transient bone marrow edema syndrome (TBMES) and avascular osteonecrosis. Materials and Methods Institutional review board approval and written informed consent were obtained. Thirty-two patients (21 men, 11 women; mean age, 48 years; 26 hips, 10 knees) underwent conventional MR imaging and a dynamic contrast-enhanced three-dimensional spoiled gradient-echo sequence at 3 T. Parameter maps for mean transit time (MTT) and plasma flow (PF) were evaluated qualitatively and quantitatively. Differences in perfusion patterns were analyzed by using the Fisher exact test. Regions of interest were drawn in areas of high PF and long MTT on each parametric map. Mean, median, standard deviation, minimum, and maximum values were determined. TBMES and osteonecrosis were compared statistically by using the Mann-Whitney U and Wilcoxon signed-rank tests, with a P value of less than .05 considered indicative of a significant difference. Results Nineteen joints with TBMES and 17 joints with osteonecrosis were evaluated. TBMES joints showed a subchondral elongated area of high PF and low MTT that was surrounded by an area of long MTT and low PF. Osteonecrosis joints showed a subchondral area with low or no detectable PF and MTT adjacent to the joint surface, which was surrounded by a rim of high PF and intermediate MTT. Patterns for TBMES and osteonecrosis did not overlap. A significant difference (P < .001) in PF in the immediate subchondral area was found between TBMES and osteonecrosis; in joints with osteonecrosis, this was comparable to background noise, and therefore, could not be quantified. In the circumscribed rim of high PF and intermediate MTT, which was only found in joints with osteonecrosis, mean ± standard deviation PF was 18.9 mL/100 mL per minute ± 11.0 and mean MTT was 213.3 seconds ± 56.8. No significant difference between TBMES and osteonecrosis was found for MTT (P = .09) and PF (P = .75) in the surrounding area. Conclusion Parameter maps derived at dynamic contrast-enhanced MR imaging with high temporal resolution can allow differentiation of osteonecrosis from TBMES in hip and knee joints. © RSNA, 2016 Online supplemental material is available for this article.


Assuntos
Doenças da Medula Óssea/diagnóstico por imagem , Edema/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética/métodos , Osteonecrose/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Síndrome
11.
Clin Endocrinol (Oxf) ; 86(3): 325-331, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27748964

RESUMO

OBJECTIVE: To evaluate volumetric and densitometric properties of the adrenal glands in patients with unilateral and bilateral disease in comparison with normal controls. DESIGN: A total of 77 patients (56 males and 21 females) diagnosed with primary aldosteronism (PA) with a mean age of 53 ± 10 years were prospectively enrolled. Unenhanced and contrast-enhanced computed tomography scans were analysed for adrenal volumes and mean densities. These values were compared with normal controls and between PA subtypes. RESULTS: Adrenals containing an aldosterone-producing adenoma (APA, n = 56) had on average higher attenuation values as compared to adrenals with bilateral adrenal hyperplasia (n = 21). Mean adrenal gland volume in PA patients was not significantly different between PA subtypes. In comparison with normal adrenal glands, volumes were significantly higher in PA patients (P < 0·0001) including adrenals contralateral to APAs, which were significantly larger in comparison with controls. CONCLUSION: Independent of subtype differentiation, adrenal volumetry reveals higher adrenal volumes in PA patients in comparison with normal controls. These findings provide indirect evidence for a general adrenal growth dysregulation in the context of PA.


Assuntos
Glândulas Suprarrenais/patologia , Hiperaldosteronismo/diagnóstico , Adenoma/metabolismo , Adenoma/patologia , Glândulas Suprarrenais/crescimento & desenvolvimento , Adulto , Idoso , Aldosterona/metabolismo , Estudos de Casos e Controles , Diagnóstico Diferencial , Feminino , Alemanha , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Tomografia Computadorizada por Raios X , Adulto Jovem
12.
NMR Biomed ; 30(3)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26114411

RESUMO

Diffusion-weighted MRI (DWI) of the vertebral bone marrow is a clinically important tool for the characterization of bone-marrow pathologies and, in particular, for the differentiation of benign (osteoporotic) and malignant vertebral compression fractures. DWI of the vertebral bone marrow is, however, complicated by some unique MR and tissue properties of vertebral bone marrow. Due to both the spongy microstructure of the trabecular bone and the proximity of the lungs, soft tissue, or large vessels, substantial magnetic susceptibility variations occur, which severely reduce the magnetic field homogeneity as well as the transverse relaxation time T*2 , and thus complicate MRI in particular with echoplanar imaging (EPI) techniques. Therefore, alternative diffusion-weighting pulse sequence types such as single-shot fast-spin-echo sequences or segmented EPI techniques became important alternatives for quantitative DWI of the vertebral bone marrow. This review first describes pulse sequence types that are particularly important for DWI of the vertebral bone marrow. Then, data from 24 studies that made diffusion measurements of normal vertebral bone marrow are reviewed; summarizing all results, the apparent diffusion coefficient (ADC) of normal vertebral bone marrow is typically found to be between 0.2 and 0.6 × 10-3 mm2 /s. Finally, DWI of vertebral compression fractures is discussed. Numerous studies demonstrate significantly greater ADCs in osteoporotic fractures (typically between 1.2 and 2.0 × 10-3 mm2 /s) than in malignant fractures or lesions (typically 0.7-1.3 × 10-3 mm2 /s). Alternatively, several studies used the (qualitative) image contrast of diffusion-weighted acquisitions for differentiation of lesion etiology: a very good lesion differentiation can be achieved, particularly with diffusion-weighted steady-state free precession sequences, which depict malignant lesions as hyperintense relative to normal-appearing vertebral bone marrow, in contrast to hypointense or isointense osteoporotic lesions. Copyright © 2015 John Wiley & Sons, Ltd.


Assuntos
Doenças da Medula Óssea/diagnóstico por imagem , Medula Óssea/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Reconhecimento Automatizado de Padrão/métodos , Doenças da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Animais , Medula Óssea/patologia , Medicina Baseada em Evidências , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coluna Vertebral/patologia
13.
Neuroradiology ; 59(4): 403-409, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28324122

RESUMO

PURPOSE: The aim of this study is to evaluate the MR imaging behavior of ferrous (Fe2+) and ferric (Fe3+) iron ions in order to develop a noninvasive technique to quantitatively differentiate between both forms of iron. METHODS: MRI was performed at 3 T in a phantom consisting of 21 samples with different concentrations of ferrous and ferric chloride solutions (between 0 and 10 mmol/L). A multi-echo spoiled gradient-echo pulse sequence with eight echoes was used for both T 2* and quantitative susceptibility measurements. The transverse relaxation rate, R 2* = 1/T 2*, was determined by nonlinear exponential fitting based on the mean signals in each sample. The susceptibilities, χ, of the samples were calculated after phase unwrapping and background field removal by fitting the spatial convolution of a unit dipole response to the measured internal field map. Relaxation rate changes, ΔR 2*(c Fe), and susceptibility changes, Δχ(c Fe), their linear slopes, as well as the ratios ΔR 2*(c Fe) / Δχ(c Fe) were determined for all concentrations. RESULTS: The linear slopes of the relaxation rate were (12.5 ± 0.4) s-1/(mmol/L) for Fe3+ and (0.77 ± 0.09) s-1/(mmol/L) for Fe2+ (significantly different, z test P < 0.0001). The linear slopes of the susceptibility were (0.088 ± 0.003) ppm/(mmol/L) for Fe3+ and (0.079 ± 0.006) ppm/(mmol/L) for Fe2+. The individual ratios ΔR 2*/Δχ were greater than 40 s-1/ppm for all samples with ferric solution and lower than 20 s-1/ppm for all but one of the samples with ferrous solution. CONCLUSION: Ferrous and ferric iron ions show significantly different relaxation behaviors in MRI but similar susceptibility patterns. These properties can be used to differentiate ferrous and ferric samples.


Assuntos
Íons/química , Ferro/química , Imageamento por Ressonância Magnética/métodos , Cloretos , Compostos Férricos , Imagens de Fantasmas
14.
J Comput Assist Tomogr ; 41(2): 254-262, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27636247

RESUMO

OBJECTIVE: The aim of this study was to define optimal tube potential for soft tissue and vessel visualization in dose-reduced chest CT protocols using model-based iterative algorithm in average and overweight patients. METHODS: Thirty-six patients receiving chest CT according to 3 protocols (120 kVp/noise index [NI], 60; 100 kVp/NI, 65; 80 kVp/NI, 70) were included in this prospective study, approved by the ethics committee. Patients' physical parameters and dose descriptors were recorded. Images were reconstructed with model-based algorithm. Two radiologists evaluated image quality and lesion conspicuity; the protocols were intraindividually compared with preceding control CT reconstructed with statistical algorithm (120 kVp/NI, 20). Mean and standard deviation of attenuation of the muscle and fat tissues and signal-to-noise ratio of the aorta were measured. RESULTS: Diagnostic images (lesion conspicuity, 95%-100%) were acquired in average and overweight patients at 1.34, 1.02, and 1.08 mGy and at 3.41, 3.20, and 2.88 mGy at 120, 100, and 80 kVp, respectively. Data are given as CT dose index volume values. CONCLUSIONS: Model-based algorithm allows for submillisievert chest CT in average patients; the use of 100 kVp is recommended.


Assuntos
Peso Corporal , Modelos Teóricos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sobrepeso , Estudos Prospectivos , Radiografia Torácica/instrumentação , Tomografia Computadorizada por Raios X/instrumentação
15.
Acta Radiol ; 58(8): 906-913, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27856804

RESUMO

Background In unclear pancreatic lesions, a tissue sample can confirm or exclude the suspected diagnosis and help to provide an optimal treatment strategy to each patient. To date only one small study reported on the outcome of computed tomography (CT) fluoroscopy-guided biopsies of the pancreas. Purpose To evaluate technical success and diagnostic rate of all CT fluoroscopy-guided core biopsies of the pancreas performed in a single university center during a 10-year period. Material and Methods In this retrospective study we included all patients who underwent a CT fluoroscopy-guided biopsy of a pancreatic mass at our comprehensive cancer center between 2005 and 2014. All interventions were performed under local anesthesia on a 16-row or 128-row CT scanner. Technical success and diagnostic rates as well as complications and effective patient radiation dose were analyzed. Results One hundred and one patients (54 women; mean age, 63.9 ± 12.6 years) underwent a total of 104 CT fluoroscopy-guided biopsies of the pancreas. Ninety-eight of 104 interventions (94.2%) could be performed with technical success and at least one tissue sample could be obtained. In 88 of these 98 samples, a definitive pathological diagnosis, consistent with clinical success could be achieved (89.8%). Overall 19 minor and three major complications occurred during the intra- or 30-day post-interventional period and all other interventions could be performed without complications; there was no death attributable to the intervention. Conclusion CT fluoroscopy-guided biopsy of pancreatic lesions is an effective procedure characterized by a low major complication and a high diagnostic rate.


Assuntos
Biópsia Guiada por Imagem , Pancreatopatias/diagnóstico por imagem , Pancreatopatias/patologia , Tomografia Computadorizada por Raios X/métodos , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Eur Arch Otorhinolaryngol ; 274(8): 3029-3039, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28584970

RESUMO

Loss of neural structures (such as hair cells or neurones within the spiral ganglion) has been proposed to be involved in Menière's disease (MD) (Spoendlin et al. Acta oto-laryngologica Supplementum 499:1-21, 1; Merchant et al. Eur Arch Oto-Rhino-Laryngol Off J Eur Feder Oto-Rhino-Laryngol Soc (EUFOS) Affil German Soc Oto-Rhino-Laryngol Head Neck Surg 252(2):63-75, 2; Tsuji et al. Ann Otol Rhinol Laryngol Suppl 81:26-31, 3; Kariya, Otol Neurotol Off Publ Am Otol Soc Am Neurotol Soc Eur Acad Otol Neurotol 28(8):1063-1068, 4; Megerian Laryngoscope 115(9):1525-1535, 5) but this has yet to be confirmed. Therefore, the aim of this study was to investigate morphometric changes of VIIth and VIIIth cranial nerve in MD. MD is characterized by episodic vertigo, tinnitus, fluctuating hearing loss, and aural fullness. The exact pathophysiological mechanisms involved such as viral infections, autoimmune processes, genetic predisposition, cellular apoptosis, and oxidative stress are still not clear. Using a T2-weighted 3D-GE "constructive interference in steady state" (CISS) 3T magnetic resonance imaging (MRI) sequence, we evaluated the properties of the VIIth and VIIIth cranial nerves as they passed from the cerebellopontine angle to the inner ear modiolus. 21 patients with MD were examined along with 39 normal controls. Bidirectional nerve diameters and cross-sectional areas (CSA) were measured in a transverse plane. The comparison of study and control group showed statistically significant (P < 0.000595 after Bonferroni correction) differences between the CSA measurements. The facial, cochlear, superior vestibular, and inferior vestibular nerves (FN, CN, SVN, IVN) of MD patients were significantly larger than those of the control group, both on the MD-affected side and on the healthy side. Thus for example, the cochlear nerve CSA measurements were 0.69 ± 0.14 mm2 (P < 0.0001) in the affected ears of the unilateral MD group, 0.70 ± 0.12 mm2 (P < 0.0001) in the affected ears of the cohort including the bilateral MD group, 0.71 ± 0.13 mm2 (P < 0.0001) in the non-affected ears of the MD patients, as compared to 0.46 ± 0.14 mm2 in the control group. The perpendicular nerve diameters were found to vary according to site of measurement and type of measurement used. For example a statistically significant enlargement of the short diameter measurements of the SVN at the level of the meatus was found, but not of long diameter measurements at the same site. Although cellular death would theoretically be expected to lead to a decreased nerve thickness, our data showed a swelling of cranial nerves VII and VIII within the study group compared to our normal hearing control group. The similar reaction of the facial nerve supports mediator-based theories of MD pathophysiology.


Assuntos
Orelha Interna/inervação , Nervo Facial/diagnóstico por imagem , Doença de Meniere , Nervo Vestibulococlear/diagnóstico por imagem , Adulto , Idoso , Feminino , Alemanha , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Doença de Meniere/diagnóstico , Doença de Meniere/fisiopatologia , Pessoa de Meia-Idade
17.
Ultraschall Med ; 38(3): 244-264, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28511226

RESUMO

Endovascular aortic repair (EVAR) has become established in the treatment of abdominal aortic aneurysms and shows potential benefits such as a low perioperative morbidity and a short hospitalization duration. The follow-up after EVAR primarily consists of lifelong postinterventional imaging of the aneurysm size in order to detect complications such as endoleaks or stent dislocation. Computed tomography angiography, an imaging modality that uses ionizing radiation and that relies on a contrast medium which is dependent on thyroid and renal function, is widely used for follow-up. Meanwhile, contrast-enhanced ultrasound (CEUS) has been established as a viable, fast and cost-effective imaging alternative for the follow-up and the detection of endoleaks after EVAR with the additional benefit of being a real-time non-ionizing radiation examination and having comparable or even superior diagnostic performance. This review describes the use of CEUS for follow-up after EVAR and describes the most common pathologies.


Assuntos
Implante de Prótese Vascular , Meios de Contraste , Endoleak/diagnóstico por imagem , Procedimentos Endovasculares , Aumento da Imagem , Ultrassonografia/métodos , Angiografia por Tomografia Computadorizada , Endoleak/classificação , Seguimentos , Humanos , Imagem Multimodal , Sensibilidade e Especificidade
19.
Radiol Med ; 122(6): 449-457, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28236046

RESUMO

PURPOSE: Calcified nodules ("CN") are responsible for up to 5% of coronary-infarcts and, therefore, classified as minor criteria of "vulnerable" atherosclerotic plaque. We sought to evaluate prevalence and distribution of CN in carotid arteries in correlation with clinical symptoms. METHODS: 178 consecutive patients with unilateral ischemic stroke and carotid plaques ≥2 mm by duplex ultrasound underwent a carotid-black-blood-3T-MRI with fat-saturated pre- and post-contrast T1w-, PDw-, T2w- and TOF images using dedicated surface-coils. CN were defined as distinct calcification with an irregular, protruding, and convex luminal surface. Prevalence of CN was determined in common carotid artery ("CCA") and internal carotid artery ("ICA") in consensus by two reviewers blinded to clinical information. RESULTS: Thirty seven CN in 28 arteries of 26 patients were identified. Prevalence of CN in CCA compared to ICA was slightly higher (59 vs. 41%), but nearly similar in 66 arteries with ≥30% compared to 290 arteries with <30% stenosis (9.1 vs. 7.6%) and in the artery ipsilateral versus contralateral to stroke (7.9 vs. 7.9%; P values n.s.). Prevalence of CN was significantly higher in 40 symptomatic arteries with ≥30% stenosis compared to asymptomatic 26 arteries (15.6 vs. 0%; P = 0.04). There was a significantly higher prevalence of hypercholesterolemia and hypertension in patients with CN (57.7 vs. 36.0 and 88.5 vs. 66.7%; P values <0.05). CONCLUSION: CN were found in 7.9% of arteries with carotid-plaques ≥2 mm by duplex-ultrasound; prevalence was significantly higher in symptomatic arteries with ≥30% stenosis compared to asymptomatic with <30% stenosis, suggesting that CN play a role in pathogenesis of ischemic stroke in a small subset of patients.


Assuntos
Artérias Carótidas , Ultrassonografia Doppler Dupla , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/epidemiologia , Idoso , Feminino , Humanos , Masculino , Prevalência , Estudos Prospectivos , Calcificação Vascular/diagnóstico
20.
Stroke ; 47(11): 2797-2804, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27758942

RESUMO

BACKGROUND AND PURPOSE: Endovascular therapy in addition to standard care (EVT+SC) has been demonstrated to be more effective than SC in acute ischemic large vessel occlusion stroke. Our aim was to determine the cost-effectiveness of EVT+SC depending on patients' initial National Institutes of Health Stroke Scale (NIHSS) score, time from symptom onset, Alberta Stroke Program Early CT Score (ASPECTS), and occlusion location. METHODS: A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALYs) associated with both strategies applied in a US setting. Model input parameters were obtained from the literature, including recently pooled outcome data of 5 randomized controlled trials (ESCAPE [Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke], EXTEND-IA [Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial], MR CLEAN [Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands], REVASCAT [Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within 8 Hours of Symptom Onset], and SWIFT PRIME [Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment]). Probabilistic sensitivity analysis was performed to estimate uncertainty of the model results. Net monetary benefits, incremental costs, incremental effectiveness, and incremental cost-effectiveness ratios were derived from the probabilistic sensitivity analysis. The willingness-to-pay was set to $50 000/QALY. RESULTS: Overall, EVT+SC was cost-effective compared with SC (incremental cost: $4938, incremental effectiveness: 1.59 QALYs, and incremental cost-effectiveness ratio: $3110/QALY) in 100% of simulations. In all patient subgroups, EVT+SC led to gained QALYs (range: 0.47-2.12), and mean incremental cost-effectiveness ratios were considered cost-effective. However, subgroups with ASPECTS ≤5 or with M2 occlusions showed considerably higher incremental cost-effectiveness ratios ($14 273/QALY and $28 812/QALY, respectively) and only reached suboptimal acceptability in the probabilistic sensitivity analysis (75.5% and 59.4%, respectively). All other subgroups had acceptability rates of 90% to 100%. CONCLUSIONS: EVT+SC is cost-effective in most subgroups. In patients with ASPECTS ≤5 or with M2 occlusions, cost-effectiveness remains uncertain based on current data.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/economia , Análise Custo-Benefício , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/economia , Terapia Trombolítica/economia , Humanos , Modelos Estatísticos , Índice de Gravidade de Doença , Terapia Trombolítica/estatística & dados numéricos
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