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Diagnostic Services - CT
There are 2 main differences between ordinary spiral CT machines and multislice CT :-
- It allows the acquisition of multiple axial images with a single gantry rotation instead of a single image in each rotation like ordinary spiral CT.
- It has shorter gantry rotation period making it much faster. We can cover the whole chest, abdomen and pelvis in 15 seconds with thinner cuts and images of higher quality than those done by ordinary spiral
CT, allowing us to make 3D reconstructions for any lesion with high efficiency.
Single slice
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Multi-slice
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Advantages of Multi-slice Technology
- Increased Volume Coverage and Speed
We can cover a longer distance in a very short time
- Improved Temporal Resolution
- Decreased Image Noise
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Minimal Artifacts Formation
New examinations that are done by multislice CT :
- CT angiography of the aorta and both lower limbs down to the ankle.
- CT angiography of the coronary arteries.
- Calcium scoring for the coronary arteries
- CT angiography of the circle of Willis to detect aneurysms.
- Triphasic liver studies are faster and more able to detect focal lesions.
- Volumetric studies of the liver for the liver transplantation candidates.
- Virtual bronchoscopy and colonoscopy with higher quality.
CT Imaging:
SOMATOM Sensation from 'SIEMENS medical' that provides:
Fast, fully integrated workstream up to 16 slices reconstruction and instant data access on shared data-base for
advanced data evaluation and quantification tools to support typical examination times < 10 minutes for all
applications.
Advanced evaluation tools dedicated to cardiac and cardiovascular imaging support rapid 3D-based automated
viewing, analysis, quantification and customizable reporting.
Cardiac Imaging:
Isotropic Angiographic Imaging of the Cardiovascular System: Whole-Body angiography with nearly isotropic resolution
Motion-Free imaging of the major mediastinal vessels
Isotropic Volume Imaging of the thoracic and abdominal vasculature
Submillimeter-resolution studies of the carotid, cerebral, and renal vessels in pure arterial phase
Long-range, nearly isotropic peripheral run-offs.
Quantification of Coronary Calcification: Find evidence of coronary atherosclerosis
May be used as independent risk indicator for a future cardiac event
Exclusion of calcified/hard plaque via the absence of coronary calcium
Can be used as marker for progression of coronary atherosclerosis
Isotropic Cardiac and Coronary CT Angiography: Diagnosis of general cardiac diseases and congenital heart disease.
Detection and exclusion of significant coronary stenoses, evaluation of coronary morphology prior to intervention
and follow-up after PTCA and bypass surgery.
Visualization and evaluation of atherosclerotic non-calcified
coronary plaque and early stage preclinical coronary
artery disease. Visual 4D Imaging and Functional Analysis:
Basic left ventricular function parameters and wall motion defects can be derived as Add-On to morphology
examination by re-using the same scan data.
CT Imaging of the Heart
CT imaging of the heart is now well established in the diagnostic field after the introduction of very fast scanner known as multidetector CT (MDCT) which enables the development of ECG – Synchronized scanning and reconstruction techniques.
A stack of images are generated and reconstructed during each cardiac cycle. The combination of these images will form a volume image data set.
The use of multidetector row CT (MDCT) scanners with more detector rows enables improved temporal resolution and reduced breath holding time and thus helps to minimize motion related artifacts.
Our new machine at Cairo Scan is a 16 row multi-detector scanner (from Siemens medical system) that can efficiently perform the following tasks:
- CT coronary angiography for diagnostic and post therapeutic evaluation.
- Mural calcium scoring in the coronary arteries as a predictive test for possible risk of myocardial ischemia.
- Assessment of the cardiac morphology for diagnosis of congenital lesions and acquired diseases.
- Functional cardiac imaging by assessment of wall motion abnormalities, contractility, ejection fraction and valvular diseases.
Multi-detector CT (MDCT) angiography of the aorta and lower limb vessels is done by intravenous injection of contrast material as one bolus into a suitable upper limb vein, followed by fast helical scan from the abdomen down to the ankle using very thin sections that are reconstructed to create 3D images which are as informative as those of conventional angiography.
Advantages of MDCT Angiography as compared to Conventional Angiography:-
Less invasive with no direct arterial puncture.
Highly diagnostic comparable images with sensitivity, specificity, and accuracy about 99% as compared to conventional angiography(Ota et al 2004).
No need to stop heparin or any other anticoagulant drugs and no need for any lab. Investigation (e.g. PT, PC), that are usually required before conventional angiography.
Much faster technique that is better tolerated by the patients.
MDCT angiography is able to detect infra popliteal vessels distal to obstruction much better than conventional angiography.
Better assessment of aortic and dissecting aneurysms than single slice CT with excellent evaluation of the aortic branches.
Less amount of contrast material, less examination time, less side effects , complications and lower cost.
Less ionizing irradiation.
- The radiation exposure with MDCT angiography is 3.9 times less than that with conventional angiography (Rubin et al, 2001).
Numerous angles of view can be acquired (AP, Lat, Obliques) for any arterial segment even retrospectively with 3 dimensional reconstruction allowing better visualization.
Advanced vessel and dynamic analysis may be used for determining the exact degree of arterial diameter changes and its effects haemodynamically.
MDCT images give additional data about the surrounding structures (e.g. para aortic area, liver, spleen, pancreas, kidneys, etc.)
Images can be delivered on a CD for better viewing and retrieval of colored and source images.
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