السونار مرحلة الرابعة 🔊.

سؤال للنقاش 🌚✅ 1- A higher duty factor corresponds to: A. Less thermal risk B. More continuous energy delivery C. Shorter pulse duration D. Lower frame rate E. Higher axial resolution

قاعدة ثابتة كل ما زاد تدفق الدم نستخدم ترددات عالية. كل ما انخفض تدفق الدم نستخدم ترددات منخفضة ✅.. علاقة طرديةة بين التردد وسرعة جريان الدم 👍✅.

سؤال مرشح للدور الأول 🌚✅ The ability to distinguish two separate structures lying side-by-side is termed: A. Axial resolution B. Temporal resolution C. Lateral resolution D. Contrast resolution E. NONE ALL OF THE ABOVE

Aduilt ➡️20Hz-20KHz Ultrasound ➡️2MHz of 20MHz Medical range ➡️2-15MHz Speed of sound in water➡️1492 m/s Soft tissue ➡️1540m/s Fatty tissue ➡️1470m/s Muscle ➡️1570 m/s Air ➡️330 m/s Bone and cartilage ➡️3600 m/s Dignostic ultrasound ➡️2-18 MHz Abdomen ➡️3-5 MHz Superficial part➡️5-10 MHz Skin or eye ➡️10-30 MHz Thickness of thin disc➡️ 0.1-1 mm Linear transducer ➡️3-12MHz Sector and convex➡️1-5 MHz Accurancy ➡️0.001 inch or 0.01mm Pulsed per second ➡️1000 Velocity of fat ➡️1450 m/s Velocity of Water ➡️1480 m/s Velocity of soft tissue ➡️1450 m/s Velocity of bone ➡️4100 m/s Greater than 1 ➡️+ Less than 1 ➡️- 11% ➡️0.89➡️1dB 79%➡️0.79➡️2dB 78%➡️0.78➡️2dB 71%➡️0.71➡️3dB 50%➡️0.50➡️6dB 25%➡️12dB 12.5%➡️18dB 6% ➡️24dB Atenuation of water ➡️0.002 Atenuation of fat➡️0.66 Atenuation of soft tissue➡️0.9 Atenuation of Air ➡️12 Atenuation of bone➡️ 20 Atenuation of lung ➡️40 acoustic impedance of Air ➡️429 Acoustic impedance of water ➡️1.43*10^6 Liver and kidney reflected ➡️1% Muscle and bone reflected➡️40% Soft tissue and air reflected ➡️99% Image need for real time ➡️15 per second Ultrasound energy is limeted In 2D ,3D,4D➡️94mW/cm2