Outlines requirements and time allocation Effect on Image 20 The highest possible frequency should be used because it will result in superior resolution arger patients Selection of the proper trasducercteof c The wrong transdu can ive you pasable c in which the anatomy Keep the folowing factors inmind and changing ransducers from patien topatient Thesie of the patient For The amount of fatty or muscular tissue present. cans curved array The linear array trans cer produces a"Tectangular"image display (block shape of image) al ,gynecologic,obstetric imaging ,and also fo Linear Array Transducer Ad bea超vni如ad ncal used where there is a large window,such as in the midline or in a pregnan uterus.Cannot get between ribs Even where Sector transducer (with small transducer head )produces a pie-shaped (wedge-shaped) Advantages small ac Disadvantages The wedge-s provide a large field of iew with a convex near field.This transducer is most commonly used for scan of Much bigger field of viewgod for large structure and overviews it will fit 4 Outlines, requirements and time allocation Effect on Image Transducers are chosen according to the structure being examined and the size of the patient. The highest possible frequency should be used because it will result in superior resolution . Pediatric patients can be examined at 5 to 7.5 MHz. Lower frequencies (e.g., 3.5MHz) permit greater penetration and may be needed to scan larger patients. Transducers Selection of the proper transducer is critical to the success of a scan. The wrong transducer shape or frequency can give you passable scan in which the anatomy is demonstrated , but the pathology never shows up. Keep the following factors in mind, and don’t lazy about changing transducers from patient to patient . The type of transducer selected for a particular examination depends upon several factors: The type of examination The size of the patient For adults : 3.5MHz, For children :10MHz The amount of fatty or muscular tissue present. The echocardiographic examination is performed with a sector transducer(3.5MHz). Obstetric and gynecologic scans are usually performed with a curved array transducer(3.5MHz). The linear array transducer produces a “rectangular” image display (block shape of image) This transducer is often used in abdominal ,gynecologic, obstetric imaging ,and also for scan of small parts, and vascular imaging Linear Array Transducer Advantages “Block” shape of image allow for large field of view in abdomen and superficial areas ;excellent for small parts, and other superficial imaging Disadvantages Can only be used where there is a large window , such as in the midline or in a pregnant uterus. Cannot get between ribs Even where there are no ribs, the flat surface of the transducer makes it difficult to angle around pockets of gas or through small windows Sector transducer (with small transducer head )produces a pie-shaped (wedge-shaped) image and is commonly used in cardiac imaging The echocardiographic examination is performed with a sector transducer(3.5MHz) Sector transducer Advantages Useful for access small access: between ribs, through a urinary bladder, through a fontanel Good for angling up under or for wedging in between tight spots Disadvantages The wedge-shaped image gives you a limited near field of view Curved array transducer with a curved scan head will provide a large field of view with a convex near field . This transducer is most commonly used for scan of abdomen ,obstetrics ,and gynecology Curved array transducer Advantages ⚫ Much bigger field of view , good for large structure and overviews ⚫ Near field is wider than sector ⚫ Useful for second –and third –trimester obstetric patients, anywhere in abdomen that it will fit ⚫ 20’