Search results for " Computed Tomography"
showing 10 items of 411 documents
Reproducible coronary plaque quantification by multislice computed tomography
2007
BACKGROUND: The aim of this study was to investigate reproducibility and accuracy of computer-assisted coronary plaque measurements by multislice computed tomography coronary angiography (QMSCT-CA). METHODS AND RESULTS: Forty-eight patients undergoing MSCT-CA and coronary arteriography for symptomatic coronary artery disease and quantitative intravascular ultrasound (IVUS, QCU) were examined. Two investigators performed the QMSCT-CA twice and a third investigator performed the QCU, all blinded for each other's results. There was no difference found for the matched region of interest (ROI) lengths (QCU 29.4 +/- 13 mm vs. QMSCT-CA 29.6 +/- 13 mm, P = 0.6; total length = 1,400 mm). The compari…
Radiomics analysis of 18F-Choline PET/CT in the prediction of disease outcome in high-risk prostate cancer: an explorative study on machine learning …
2021
Objective: The aim of this study was (1) to investigate the application of texture analysis of choline PET/CT images in prostate cancer (PCa) patients and (2) to propose a machine-learning radiomics model able to select PET features predictive of disease progression in PCa patients with a same high-risk class at restaging. Material and methods: Ninety-four high-risk PCa patients who underwent restaging Cho-PET/CT were analyzed. Follow-up data were recorded for a minimum of 13 months after the PET/CT scan. PET images were imported in LIFEx toolbox to extract 51 features from each lesion. A statistical system based on correlation matrix and point-biserial-correlation coefficient has been impl…
Influence of convolution filtering on coronary plaque attenuation values: observations in an ex vivo model of multislice computed tomography coronary…
2007
Attenuation variability ( measured in Hounsfield Units, HU) of human coronary plaques using multislice computed tomography (MSCT) was evaluated in an ex vivo model with increasing convolution kernels. MSCT was performed in seven ex vivo left coronary arteries sunk into oil followingthe instillation of saline (1/infinity) and a 1/50 solution of contrast material ( 400 mgI/ml iomeprol). Scan parameters were: slices/ collimation, 16/0.75 mm; rotation time, 375 ms. Four convolution kernels were used: b30f-smooth, b36f-medium smooth, b46f-medium and b60f-sharp. An experienced radiologist scored for the presence of plaques and measured the attenuation in lumen, calcified and noncalcified plaques …
Radiation dose from multidetector CT studies in children: results from the first Italian nationwide survey
2014
Background Multidetector CT (MDCT) scanners have con- tributed to the widespread use of CT in paediatric imaging. However, concerns are raised for the associated radiation exposure. Very few surveys on radiation exposure from MDCT studies in children are available. Objective The aim of this study was to outline the status of radiation exposure in children from MDCT practice in Italy. Materials and methods In this retrospective multicentre study we asked Italian radiology units with an MDCT scanner with at least 16 slices to provide dosimetric and acquisition param- eters of CT examinations in three age groups (1–5, 6–10, 11– 15 years) for studies of head, chest and abdomen. The dosi- metric…
Transmurality of scar influences the effect of a hybrid-intervention with autologous bone marrow cell injection and aortocoronary bypass surgery (MNC…
2010
Abstract Background Cell therapy (CTx) is a strategy to support cardiac regeneration after myocardial infarction (MI). Thus far, clinical studies provided mixed results. Here, we investigated whether transmurality of the infarct may play a relevant role. Methods 18 patients (63±3years, 15 male) undergoing elective coronary artery bypass graft (CABG) surgery 2.2±0.7months post MI participated. 10 had transmural and 8 non-transmural infarct scars assessed by Tc-99m-MIBI Single-Photon Emission Computed Tomography (SPECT) and F18-FDG-Positron-Emission-Tomography (PET). During surgery, 10ml of sternal bone marrow were obtained, mononuclear cells (MNC) were isolated. At the end of surgery MNC wer…
Reducing Patient Radiation Dose With Image Noise Reduction Technology in Transcatheter Aortic Valve Procedures
2015
X-ray radiation exposure is of great concern for patients undergoing structural heart interventions. In addition, a larger group of medical staff is required and exposed to radiation compared with percutaneous coronary interventions. This study aimed at quantifying radiation dose reduction with implementation of specific image noise reduction technology (NRT) in transcatheter aortic valve implantation (TAVI) procedures. We retrospectively analyzed 104 consecutive patients with TAVI procedures, 52 patients before and 52 after optimization of x-ray radiation chain, and implementation of NRT. Patients with 1-step TAVI and complex coronary intervention, or complex TAVI procedures, were excluded…
Imaging features of pancreatic metastases: A comparison with pancreatic ductal adenocarcinoma
2018
Purpose: To compare imaging features of pancreatic metastases (PM) with those of pancreatic ductal adenocarcinomas (PDAC). Methods: CT and MR scans of 24 patients with 54 PM and 30 patients with PDAC were reviewed to evaluate the imaging features, which were compared by using a Chi square test. Results: We found a statistically significant difference between PM and PDAC based on location (P < 0.001), margins (P < 0.001), arterial enhancement (P = 0.004), rim enhancement (P < 0.001), pancreatic duct dilatation (P = 0.01), common bile duct dilatation (P = 0.003), vascular involvement (P = 0.02), parenchymal atrophy (P < 0.001), peripancreatic fluid (P = 0.03). Conclusion: Imaging features mig…
Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability
2015
Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour w…
Immunoglobulin G4-Related Aortitis and Severe Aortic Valve Stenosis Treated With Transcatheter Aortic Valve Replacement and Immunosuppression.
2021
Abstract IgG4-related disease is an immune-mediated fibro-inflammatory disorder with multisystemic involvement. Aortitis and peri-aortitis are the most common cardiovascular manifestations of the disease. We present the case of a 65-year-old man with symptomatic severe aortic stenosis and concomitant IgG4 aortitis. The diagnosis was confirmed by IgG4 serum levels, positive positron emission computed tomography (PET-CT) scans, and pathology from mediastinal dissection. Surgical aortic valve replacement (SAVR) was unfeasible owing to extensive mediastinal fibrosis, and transcatheter aortic valve replacement (TAVR) was successfully performed. As ascending aorta access for SAVR in IgG4 aortitis…
Basal Cerebral Computed Tomography as Diagnostic Tool to Improve Patient Selection in Asymptomatic Carotid Artery Stenosis
2012
One-hundred patients were included to evaluate the role of cerebral computed tomography (CT) to improve patient selection in asymptomatic internal carotid stenosis. Symptomatic patients were assigned to group A, asymptomatic patients to group B. A cerebral CT pattern A was observed in groups A and B in 60% and 20%, respectively ( P < .0001). Between A and B groups, type 6 plaques were found, respectively, in 26.7% and 7.5% of patients ( P = .01); a type 5 in 51.7% and 45% ( P = .32) of patients; and a type 4 in 21.7% and 47.5% of patients, respectively ( P = .006). Within B group, the association of CT pattern A and histological plaque level 4, 5, and 6 was, respectively, 25% ( P = .15)…