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Query: EC:3.4.24.59 (MIP)
 4,906 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Technical characteristics, acquisition modality and data representations as well as examination protocols and main clinical applications of spiral CT angiography (CTA) are described. The different methods of 2D (MPR, CPR) and 3D (SSD, MIP) data display and their advantages and limitations were investigated. We describe the examination technique representing an important tool to achieve good image quality and to make the correct diagnosis. The clinical effectiveness and the main applications in the body were studied. CTA already has a clinical role for arterial system study, while it is less indicated in the venous system because good and continuous contrast agent opacification is difficult to obtain. In our preliminary experience, CTA can be considered an effective alternative to DSA in the assessment of vascular conditions because it is easier to perform, more rapid and less invasive.
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PMID:[Angiography with spiral computed tomography. The basic principles and clinical potentials]. 759 24

This study was aimed to assess the comparative capabilities of CT angiography (CTA) and DSA in diagnosing aneurysms in different sites in a series of 20 patients. Volumes were measured during intravenous contrast agent infusion and images were then edited and reformatted as 2D and 3D displays (MPR, SSD, MIP techniques). Some of the main semiologic patterns of aneurysms were considered and the diagnostic accuracy of the 3 reconstruction techniques was assessed and compared with that of axial CT and DSA. Abdominal aortic aneurysms were analyzed separately to study the involvement of main collateral vessels. The best results were obtained with MIP and MPR in the assessment of aneurysm extent and neck. MPR is the only technique which could depict the thrombus and the best technique to demonstrate the relationships between aneurysm and adjacent structures. The MIP technique depicts calcifications and is the method of choice to demonstrate the involvement of collateral vessels by abdominal aortic aneurysms. SSD permits good assessment of the neck and of the longitudinal extent of the aneurysms but is severely limited in the analysis of the other variables.
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PMID:[Aneurysmal disease. Initial clinical experience with spiral computerized tomography angiography]. 761 2

Spiral CT allows rapid data acquisition in an entire anatomical region during a single breath-hold and permits to obtain 2D and 3D reconstructions with good diagnostic accuracy. We investigated the capabilities of spiral CT reconstructions in demonstrating esophageal cancers. Spiral CT was performed in 10 patients with esophageal cancers and in 3 patients who underwent endoprostheses placement with surgical or interventional procedures. Bidimensional (MPR, CPR, MIP) and three-dimensional reconstructions with Shaded Surface Display (SSD) were obtained at the end of each exam. In the analysis of the results, CT reconstructions were compared with previous barium esophagography. Some of the main semiologic patterns were considered: tumor visualization, longitudinal extent of the neoplasm and its relationships with adjacent structures. MPRs were obtained in 9 patients and allowed to visualize the esophageal lumen with a filling defect, the neoplastic mass and its longitudinal and extraluminal extent. SSD reconstructions was obtained in 7 patients and allowed a good assessment of longitudinal neoplasm extent in 6 patients. Neoplastic mass visualization and extraluminal tumor extent were difficult to assess in all cases. MIP reconstructions were obtained in all patients and demonstrated longitudinal neoplasm extent with good accuracy. Neo-plastic tissue was visualized only indirectly through the filling defect of the esophageal lumen. MIP allowed to define, in 5 patients, the relationships of the neoplasms with adjacent vascular structures after the intravenous administration of contrast agent. In conclusion, we consider that Spiral CT reconstructions can be useful for a more accurate staging of esophageal cancers.
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PMID:[Bi- and tridimensional reconstruction with spiral computerized tomography in esophageal neoplasms. Preliminary clinical applications]. 897 6

We assessed the improvement of longitudinal resolution in helical CT by deblurring techniques in a phantom and 8 head and neck patients. After helical scanning with 3- or 5-mm-collimation and 3- or 5 mm/sec table feed, overlapped axial images were reconstructed at every 0.3 or 0.5 mm pitch. Deblurring techniques were applied to these data. The slice profile and longitudinal resolution were improved by deblurring. Longitudinal resolution increased with the strength of deblurring. Image sharpness was improved in reconstructed images of MPR, MIP and 3D, and better visualization of the peripheral vessels was obtained in CTAs.
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PMID:[Improvement of longitudinal resolution by deblurring technique in helical CT of the head and neck]. 912 78

We evaluated the use of deblurring technique by digital deconvolution for improving the longitudinal resolution in helical CT in a phantom and CT images of head and neck patients. After performing the helical scanning, overlapped axial images were reconstructed at 1/10 of the actual collimation. Then, the deblurring technique was performed. Results revealed that the resolution of slice profiles was improved after deblurring. Further, the longitudinal resolution increased as the strength of the deconvolution increased, at the expense of an increase in helical artifacts. The sharpness and visualization of horizontally running structures were improved in the reconstructed MPR, MPVR, MIP and 3D images in both the phantom and the images of all patients. Also, visualization of the peripheral vessels in CTAs was improved.
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PMID:The use of deblurring technique for improving the longitudinal resolution in helical CT of the head and neck region. 925 93

RF-refocused single or multi-shot EPI provides high-contrast 2D or 3D T2-weighted images in a very short scan time. Applications include MR cholangiopancreatography, MR myelography, imaging detailed structures of the internal auditory canal and in situations in which very fast T2 imaging is required. FASE offers both 2D and 3D techniques. 2D FASE technique permits high-resolution images of 384 matrix or more to be obtained at 2 to 3 seconds per image. It is easy to perform and suitable for screening. 3D FASE permits acquisition of isotropic voxels, allowing high-resolution viewing from any desired direction by post-processing (MIP and/or MPR). This technique is best suited to detailed examinations in which multiple projection angles will be reconstructed or high-resolution diagnosis of source images.
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PMID:[FASE (fast advanced spin echo)]. 984 98

MR-cholangiopancreatography (MRCP) is a new method that is non-invasive and permits volume data collection and three-dimensional expression. With the three-dimensional Fourier transform fast asymmetric spin echo (3DFT-FASE) method, a higher spatial resolution can be obtained both in-pain and in slice selecting direction. In this paper, the usefulness of this new technique is investigated in the clinical diagnosis of MIP images and MPR. The study was performed in 10 normal volunteers and 21 patients with abnormalities in the pancreas or bile-duct sustem. The study was done using a 1.5 Tesla super-conductive machine. The MRCP images were interpreted by three radiologists. In most cases good images were obtained. The additional clinical information provided by MPR was remarkably useful in cystic lesions, especially in mucinous cystic neoplasm of the pancreas. Even when the intestine overlapped the pancreas, it was possible to evaluate the pancreatic duct by MPR. Three-dimensional observation and clinically useful diagnosis were possible by utilizing the advantageds of the 3DFT-FASE method appears quite useful in clinical application.
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PMID:Clinical evaluation of three-dimensional MR-cholangiopancreatography using three-dimensional Fourier transform fast asymmetric spin echo method (3DFT-FASE): usefulness of observation by multi-planar reconstruction. 1037 47

Because it is a non-invasive method, Magnetic Resonance Angiography has more and more indications in the thorax, particularly with the help of use of contrast media. Different types of sequences used (Cine-MR, Gradient-echo 2D and Gadolinium enhanced breath-hold and non breath-hold 3D) are described as well as acquisition parameters and reconstructions from natives images. Post-processing techniques (MIP, MPR, 3D Surface Rendering) and their limitations depending upon the region explored are explained. Major indications (congenital anomalies of the great vessels, aneurysms, dissections, post-operative studies, evaluation of coronary arteries) are illustrated and the role of MRA compared to the other invasive and non invasive modalities is discussed.
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PMID:[MRI angiography of the thoracic vessels including coronary arteries: techniques and indications]. 1050 61

The authors have presented several 3-D CT imaging techniques that may be useful in dentistry. MPR and dental MPR provides cross-sectional images of the jaws and the dental arches, and its utility in implant treatment planning is widely recognized. SSD allows the clinician to visualize the surface of an anatomic structure that is selected by a threshold value. Volume rendering is a powerful and flexible three-dimensional imaging technique that can create various unique images. MIP may be useful in contrast-enhanced CT examinations, such as sialography. Model production and virtual reality three-dimensional imaging may become major techniques in the near future. Although the increased radiation dose to the patients has to be considered, future imaging demands will bring more access to 3-D CT imaging by dental patients and, with adequate three-dimensional rendering techniques, more accurate diagnosis and treatment planning.
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PMID:Three-dimensional computed tomography imaging in dentistry. 1074 Jul 75

The aim of the study was to investigate the use of 2D and 3D reconstructions in examinations of the aorta with CT and MRI. Postprocessing of 5 data sets including 2D MPR reconstructions, 3D MIP reconstructions and 3D volume rendering reconstructions acquired with contrast enhanced CTA and 5 data sets acquired with contrast enhanced MRA were performed. The luminal diameter, the length of the aneurysm and the detection of dissection was assessed for the reconstructions and the source images. Aneurysms and dissections of the aorta were correctly identified on source images. 2D MPR reconstructions and source images allow for a clear and easy image analysis including cases with high signal intensity or density of surrounding tissue and complex anatomical structures. The diameter and length of pathological findings can be determined correctly wit 2D MPR reconstructions, even when the vessel orientation is not exactly inplane or throughplane in relation to the source images. MIP reconstructions are suitable for contrast enhanced MRA data sets with high C/N ratio and volume rendering reconstructions are suitable for contrast enhanced CTA data sets, where calcifications and bone have also high density. For 3D visualization of large volumes MIP reconstructions are the method of choice for MRA and volume rendering reconstructions for CTA, respectively. In addition, 2D MPR can be necessary to determine the diameter and length of pathological findings.
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PMID:[Reconstruction methods in postprocessing of CT- and MR-angiography of the aorta]. 1155 84


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