1,927 research outputs found

    Type IV dual left anterior descending coronary artery evaluated using multislice computed tomography: Anatomy of a rare coronary anomaly

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    Images in cardiovascular medicine Type IV dual left anterior descending coronary artery evaluated using multislice computed tomography: anatomy of a rare coronary anomal

    MR quantitative biomarkers of non-alcoholic fatty liver disease: technical evolutions and future trends

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    Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis as the earliest manifestation and hallmark, and ranges from benign fatty liver to non-alcoholic steatohepatitis (NASH). Liver biopsy (LB) is considered the reference standard for NAFLD diagnosis, grading and characterization, but it is limited by its invasiveness and observer-dependence. Among imaging surrogates for the assessment of hepatic steatosis, MR is the most accurate. (1)H MR spectroscopy (MRS) provides a quantitative biomarker of liver fat content (LFC) called proton density fat fraction (PDFF), but it is time-consuming, not widely available and limited in sample size. Several MR imaging (MRI) techniques, in particular fat suppression and in-opposed phase techniques, have been used to quantify hepatic steatosis, mainly estimating LFC from water and fat signal intensities rather than proton densities. Several technical measures have been introduced to minimize the effect of confounding factors, in particular a low flip angle, a multiecho acquisition and a spectral modeling of fat with multipeak reconstruction to address respectively T1 effect, T2* effect, and the multifrequency interference effects of fat protons, allowing to use MRI to estimate LFC based on PDFF. Tang et al. evaluated MRI-estimated PDFF, obtained by applying the above-mentioned technical improvements, in the assessment of hepatic steatosis, using histopathology as the reference standard. The identification of PDFF thresholds, even though to be further explored and validated in larger and more diverse cohorts, is useful to identify steatosis categories based on MRI-based steatosis percentages. MRI, with the new refined techniques which provide a robust quantitative biomarker of hepatic steatosis (PDFF) evaluated on the whole liver parenchyma, is a promising non-invasive alternative to LB as the gold standard for steatosis diagnosis and quantification

    Noninvasive evaluation of coronary artery stents patency after PTCA: role of Multislice Computed Tomography.

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    Restenosis of a coronary artery treated with stent implantation is a well-known process that can compromise over time the success of a coronary angioplasty and, accordingly, treated patients must undergo periodic controls. We have recently witnessed a shift towards a greater use of Multi-slice CT (msCT) in the study of coronary disease without its precise indications and limits having yet been underlined. The purpose of our study is to assess the role of msCT in the follow-up of patients treated with coronary angioplasty.Forty-eight patients, for a total of 72 lesions, who underwent treatment with a slotted tube stent implant, had an msCT examination 1 week before scheduled coronary angiography, and the results were compared. 34 stents/72 (47.2\%) were inserted on the left anterior descending; 21/72 (29.2\%) on the right coronary; 17/72 (23.6\%) on the circumflex artery or obtuse marginal branches.The observation of the opacification of the vessel located distally to treated segments allowed us to assess the patency of all stents. Coronary angiography identified a significant intrastent restenosis or a stent occlusion in 12 of the 72 stents analysed (16.7\%). msCT enabled easier visualization of the lumen of the treated artery and its differentiation from the stent struts in the ones located on the left anterior descending artery than those on the circumflex (28 stents out of 34 [82.4\%] vs 13/17 [76.5\%]; p3.5 mm (OR 2.97 [IC 95\%: from 1.67 to 4.86]; p<0.01).The msCT technology available at present makes the study of smaller stents and those positioned on the right coronary artery and circumflex rather complex; on the other hand msCT appears a promising study method for stents greater then 3.5 mm and for those positioned on the proximal segment of the left anterior descending artery

    Subjective Symptoms in Magnetic Resonance Imaging Personnel: A Multi-Center Study in Italy

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    Introduction: Magnetic Resonance Imaging (MRI) personnel have significant exposure to static and low-frequency time-varying magnetic fields. In these workers an increased prevalence of different subjective symptoms has been observed. The aim of our study was to investigate the prevalence of non-specific subjective symptoms and of “core symptoms” in a group of MRI personnel working in different centers in Italy, and of possible relationships with personal and occupational characteristics.Methods: The occurrence of 11 subjective symptoms was evaluated using a specific questionnaire with 240 subjects working in 6 different Italian hospitals and research centers, 177 MRI health care and research personnel and 63 unexposed subjects employed in the same departments. Exposure was subjectively investigated according to the type of MRI scanner (≤1.5 vs. ≥3 T) and to the number of MRI procedures attended and/or performed by the personnel, even if no information on how frequently the personnel entered the scanner room was collected. The possible associations among symptoms and estimated EMF exposure, the main characteristics of the population, and job stress perception were analyzed.Results: Eighty-six percent of the personnel reported at least one symptom; drowsiness, headache, and sleep disorders were the most frequent. The total number of symptoms did not differ between exposed persons and controls. Considering the total number of annual MRI procedures reported by the personnel, no significant associations were found nor with the total number of symptoms, nor with “core symptoms.” Only subjects complaining of drowsiness also reported a significantly higher mean annual number of MRI procedures with ≤ 1.5 T scanners when compared with exposed subjects without drowsiness. In a multivariate model, subjects with a high level of perceived stress complained of more symptoms (p = 0.0002).Conclusions: Our study did not show any association between the occurrence of reversible subjective symptoms, including the more specific “core symptoms,” and the occupational exposure of MRI personnel to static and low-frequency time-varying magnetic fields. On the other hand, the role played by occupational stress appears to be not negligible. In further research in this field, measurements of EMF exposure should be considered

    Quantificazione del calcio coronarico (calcium score) attraverso l'utilizzo di nuove tecniche di imaging e suo ruolo prognostico in vari sottogruppi di pazienti

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    Coronary artery disease is the first cause of mortality in industrialized countries notwithstanding the diagnostic and therapeutic progresses. Electron beam computed tomography and multislice computed tomography with calcium score software seem to have an important role in the early diagnosis of coronary artery disease. Coronary calcium is associated with a high probability of subclinical atherosclerosis. In particular the area of calcification has a positive correlation with the histologically analyzed area of the atheromatous burden plaque. The pathophysiological mechanism may be that the calcium adherent to the plaque makes unstable the plaque with possible rupture. Several studies have analyzed the predictive value of calcium score in various subgroups of patients (asymptomatic, with chest pain, with diabetes) and they have confirmed the presence of large calcific deposits in subjects with a high cardiovascular risk. The correlation of the other risk factors with calcium score is unclear and whether this is due to genetic predisposition requires further investigation. © 2003 CEPI Srl

    Lung and Heart Diseases Are Better Predicted by Pack-Years than by Smoking Status or Duration of Smoking Cessation in HIV Patients

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    BACKGROUND: The objective of this study was to assess the relationship of pack-years smoking and time since smoking cessation with risk of lung and heart disease. METHODS: We investigated the history of lung and heart disease in 903 HIV-infected patients who had undergone thoracic computed tomography (CT) imaging stratified by smoking history. Multimorbidity lung and heart disease (MLHD) was defined as the presence of 65 2 clinical or subclinical lung abnormalities and at least one heart abnormality. RESULTS: Among 903 patients, 23.7% had never smoked, 28.7% were former smokers and 47.6% were current smokers. Spirometry indicated chronic obstructive pulmonary disease in 11.4% of patients and MLHD was present in 53.6%. Age, male sex, greater pack-years smoking history and smoking cessation less than 5 years earlier vs. more than 10 years earlier (OR 2.59, 95% CI 1.27-5.29, p = 0.009) were independently associated with CT detected subclinical lung and heart disease. Pack-years smoking history was more strongly associated with MLHD than smoking status (p<0.001). CONCLUSIONS: MLHD is common even among HIV-infected patients who never smoked and pack- years smoking history is a stronger predictor than current smoking status of MLHD. A detailed pack-years smoking history should be routinely obtained and smoking cessation strategies implemente

    Emphysema distribution and diffusion capacity predict emphysema progression in human immunodeficiency virus infection

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    Background Chronic obstructive pulmonary disease (COPD) and emphysema are common amongst patients with human immunodeficiency virus (HIV). We sought to determine the clinical factors that are associated with emphysema progression in HIV. Methods 345 HIV-infected patients enrolled in an outpatient HIV metabolic clinic with \uf42 chest computed tomography scans made up the study cohort. Images were qualitatively scored for emphysema based on percentage involvement of the lung. Emphysema progression was defined as any increase in emphysema score over the study period. Univariate analyses of clinical, respiratory, and laboratory data, as well as multivariable logistic regression models, were performed to determine clinical features significantly associated with emphysema progression. Results 17.4% of the cohort were emphysema progressors. Emphysema progression was most strongly associated with having a low baseline diffusion capacity of carbon monoxide (DLCO) and having combination centrilobular and paraseptal emphysema distribution. In adjusted models, the odds ratio (OR) for emphysema progression for every 10% increase in DLCO percent predicted was 0.58 (95% confidence interval [CI] 0.41-0.81). The equivalent OR (95% CI) for centrilobular and paraseptal emphysema distribution was 10.60 (2.93-48.98). Together, these variables had an area under the curve (AUC) statistic of 0.85 for predicting emphysema progression. This was an improvement over the performance of spirometry (forced expiratory volume in 1 second to forced vital capacity ratio), which predicted emphysema progression with an AUC of only 0.65. Conclusion Combined paraseptal and centrilobular emphysema distribution and low DLCO could identify HIV patients who may experience emphysema progression

    Molecular Imaging of Vascular Calcification with 18 F-Sodium-Fluoride in Patients Infected with Human Immunodeficiency Virus

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    18F-Sodium Fluoride (NaF) accumulates in areas of active hydroxyapatite deposition and potentially unstable atherosclerotic plaques. We assessed the presence of atherosclerotic plaques in 50 adult patients with HIV (HIV+) who had undergone two cardiac computed tomography scans to measure coronary artery calcium (CAC) progression. CAC and its progression are predictive of an unfavorable prognosis. Tracer uptake was quantified in six arterial territories: aortic arch, innominate carotid artery, right and left internal carotid arteries, left coronary (anterior descending and circumflex) and right coronary artery. Thirty-one patients showed CAC progression and 19 did not. At least one territory with high NaF uptake was observed in 150 (50%) of 300 arterial territories. High NaF uptake was detected more often in non-calcified than calcified areas (68% vs. 32%), and in patients without than in those with prior CAC progression (68% vs. 32%). There was no correlation between clinical and demographic variables and NaF uptake. In clinically stable HIV+ patients, half of the arterial territories showed a high NaF uptake, often in the absence of macroscopic calcification. NaF uptake at one time point did not correlate with prior progression of CAC. Prospective studies will demonstrate the prognostic significance of high NaF uptake in HIV+ patients

    Abdominal Fat Characteristics and Mortality in Rectal Cancer: A Retrospective Study

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    : The aim of this study was to evaluate the association of adipose tissue characteristics with survival in rectal cancer patients. All consecutive patients, diagnosed with stage II-IV rectal cancer between 2010-2016 using baseline unenhanced Computed Tomography (CT), were included. Baseline total, subcutaneous and visceral adipose tissue areas (TAT, SAT, VAT) and densities (TATd, SATd, VATd) at third lumbar vertebra (L3) were retrospectively measured. The association of these tissues with cancer-specific and progression-free survival (CCS, PFS) was assessed by using competitive risk models adjusted by age, sex and stage. Among the 274 included patients (median age 70 years, 41.2% females), the protective effect of increasing adipose tissue area on survival could be due to random fluctuations (e.g., sub-distribution hazard ratio-SHR for one cm2 increase in SAT = 0.997; 95%confidence interval-CI = 0.994-1.000; p = 0.057, for CSS), while increasing density was associated with poorer survival (e.g., SHR for one Hounsfield Unit-HU increase in SATd = 1.03, 95% CI = 1.01-1.05, p = 0.002, for CSS). In models considering each adipose tissue area and respective density, the association with CSS tended to disappear for areas, while it did not change for TATd and SATd. No association was found with PFS. In conclusion, adipose tissue density influenced survival in rectal cancer patients, raising awareness on a routinely measurable variable that requires more research efforts
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