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Coronary anatomy
Coronary Anatomy On the left is an overview of the coronary arteries in the anterior projection. Left Main or Left Coronary Artery (LCA) Left Anterior Descending (LAD) Diagonal branches (D1, D2) Septal branches Circumflex (Cx) Marginal branches (M1, M2) or Obtuse Marginal (OM) Right Coronary Artery (RCA) Acute marginal branch (AM) AV node branch Posterior Descending Artery (PDA) تشريح الشرايين التاجية (Coronary Anatomy) على اليسار نظرة عامة على الشرايين التاجية في الإسقاط الأمامي (Anterior Projection). الشريان التاجي الأيسر الرئيسي (Left Main أو Left Coronary Artery - LCA) الشريان الأمامي النازل الأيسر (Left Anterior Descending - LAD) الفروع القطرية (Diagonal branches - D1, D2) الفروع الحاجزية (Septal branches) الشريان الدائري (Circumflex - Cx) الفروع الهامشية (Marginal branches - M1, M2) أو الفرع الهامشي المنفرج (Obtuse Marginal - OM) الشريان التاجي الأيمن (Right Coronary Artery - RCA) الفرع الهامشي الحاد (Acute marginal branch - AM) فرع عقدة الأذين البطيني (AV node branch) الشريان ال...
Artifact In CT
Artifact In CT Artifact Origins Physics Based Beam hardening Partial volume effect. Photon starvation. Under sampling. Patient Based Metal. Patient motion Inadequate scan field. Scanner Based Detector sensitivity Spiral Artifacts in MSCT 3D and MPR artifacts: Stair step artifacts. Zebra artifact Windmill artifact. Cone beam artifact Physics Based Beam Hardening Causes The average energy of the X-ray beam becomes greater (Harder) as it passes through tissue. Because the attenuation of bone is greater than tissue, bone causes more beam Hardening than soft tissue. The beam hardening occurs artifacts in CT because rays from some projection angle are hardened to a differing extent than rays from other angles, confusing the reconstruction algorithm. Beam hardening cause broad dark or streaks artifacts. (1) Physics Based Beam Hardening Correction Prefilter the X-ray beam near the focus ( bowtie) Avoid highly absorbing bony regions by patient positioning or gantry tilt. Algorithms. Beam h...































































































































































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