Search results for "DCT"
showing 10 items of 25 documents
Cumulative doses analysis in young trauma patients: a single-centre experience
2015
Multidetector computed tomography (MDCT) represents the main source of radiation expo- sure in trauma patients. The radiation exposure of young patients is a matter of considerable medical concern due to possible long-term effects. Multiple MDCT stud- ies have been observed in the young trauma population with an increase in radiation exposure. We have identi- fied 249 young adult patients (178 men and 71 women; age range 14-40 years) who had received more than one MDCT study between June 2010 and June 2014. According to the International Commission on Radio- logical Protection publication, we have calculated the cumulative organ dose tissue-weighting factors by using CT-EXPO software ® . We…
Automated detection of lung nodules in low-dose computed tomography
2007
A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector computed-tomography (CT) images has been developed in the framework of the MAGIC-5 Italian project. One of the main goals of this project is to build a distributed database of lung CT scans in order to enable automated image analysis through a data and cpu GRID infrastructure. The basic modules of our lung-CAD system, consisting in a 3D dot-enhancement filter for nodule detection and a neural classifier for false-positive finding reduction, are described. The system was designed and tested for both internal and sub-pleural nodules. The database used in this study consists of 17 low…
Italian multicenter, prospective study to evaluate the negative predictive value of 16- and 64-slice MDCT imaging in patients scheduled for coronary …
2009
This was a prospective, multicenter study designed to evaluate the utility of MDCT in the diagnosis of coronary artery disease (CAD) in patients scheduled for elective coronary angiography (CA) using different MDCT systems from different manufacturers. Twenty national sites prospectively enrolled 367 patients between July 2004 and June 2006. Computed tomography (CT) was performed using a standardized/optimized scan protocol for each type of MDCT system (> or =16 slices) and compared with quantitative CA performed within 2 weeks of MDCT. A total of 284 patients (81%) were studied by 16-slice MDCT systems, while 66 patients (19%) by 64-slice MDCT scanners. The primary analysis was on-site/off…
Improving diagnostic accuracy of MDCT coronary angiography in patients with mild heart rhythm irregularities using ECG editing
2006
OBJECTIVE. The objective of our study was to compare diagnostic accuracy of MDCT coronary angiography in a population of patients with mild heart rhythm irregularities before and after editing the ECG. SUBJECTS AND METHODS. Thirty-eight patients who underwent MDCT coronary angiography and conventional coronary angiography were enrolled in the study. The inclusion criterion was the presence of mild heart rhythm irregularities (i.e., premature beats; atrial fibrillation; mistriggering; or low heart rate, defined as 40 beats per minute or less) during the scan. All patients underwent MDCT with the following parameters: 16 detectors; collimation, 0.75 mm; gantry rotation time, 375 msec; 120 kV;…
Anatomical variants and anomalies of the coronary tree studied with MDCT coronary angiography
2010
Le anomalie delle arterie coronariche sono presenti alla nascita nella maggior parte dei casi asintomatiche ma possono manifestarsi con sintomatologia severa quale angina pectoris o addirittura l’arresto cardiaco. L’angiografia coronarica mediante tomografia computerizzata multistrato (TCMS) permette, tramite ricostruzioni multiplanari secondo piani curvilinei e riformattazioni 3D, la visualizzazione dell’albero coronarico e delle sue varianti ed anomalie in maniera non invasiva, fornendo migliore e più accurata alternativa alla angiografia coronarica (AC). Lo scopo di questo pictorial consiste nella descrizione mediante immagini TCMS con ricostruzioni multiplanari e 3D delle principali var…
TRANS-CRANIAL MRI-GUIDED FOCUSED ULTRASOUND SURGERY (TCMRGFUS): ITALIAN AND WORLD-FIRST EXPERIENCE AT 1.5 TESLA
2016
Introduction: Transcranial magnetic resonance-guided focused ultrasound surgery (tcMRgFUS) is a promising new technology for the noninvasive treatment of various brain disorders. Here, we present our preliminary results achieved with the first Italian installation of a transcranial MRI-guided focused ultrasound surgery (tcMRgFUS) certified system for functional neurosurgery. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. Materials and Methods: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed me…
Hybrid blind robust image watermarking technique based on DFT-DCT and Arnold transform
2018
In this paper, a robust blind image watermarking method is proposed for copyright protection of digital images. This hybrid method relies on combining two well-known transforms that are the discrete Fourier transform (DFT) and the discrete cosine transform (DCT). The motivation behind this combination is to enhance the imperceptibility and the robustness. The imperceptibility requirement is achieved by using magnitudes of DFT coefficients while the robustness improvement is ensured by applying DCT to the DFT coefficients magnitude. The watermark is embedded by modifying the coefficients of the middle band of the DCT using a secret key. The security of the proposed method is enhanced by appl…
Characterization of focal liver lesions undetermined at grayscale US: contrast-enhanced US versus 64-row MDCT and MRI with liver specific contrast ag…
2011
Role of 64-slices MDCT-enterography in the evaluation of patients with suspected small bowel neoplasm.
2010
Purpose Methods and Materials Results Conclusion References Personal Information