What are ultrasound waves : A udible sound waves lie between 20 and 20,000 Hz.

1. What are ultrasound waves: Audible sound waves lie between 20 and 20,000 Hz. Ultra sound uses sound waves with a far greater frequency between 1 and 30 MHz.

2. Anatomical directions These terms are used both to describe the direction of movement of the transducer and to describe the relationship between various organs or structures. It is a standard labeling nomenclature used to show where structures lie in relation to each other.

3. Planes or body sections There are four mainscanning planes: sagittal, transverse, coronal, and oblique. Scan planes can apply to either the whole body or an individual organ.

4. IMAGE orientation To assist with orientation, most transducers have a notch or mark on the transducer that corresponds to a mark on the screen. Images are displayed on the ultrasound screen in a standardized way. Imagine standing at the foot of a bed and looking up at a large loaf of sliced bread. The captured image is projected as a slice, lifted onto the screen. IN TRANSVERSE SECTION : Anterior abdominal wall--- anterior aspect of image. Spine—posterior aspect of image Right side of body—left side of image Left side of body –right side of image IN SAGITTAL SECTION: Anterior abdominal wall--- anterior aspect of image. Spine—posterior aspect of image Head end—left side of image Foot end—right side of image

5. A transverse image is orientated with the patient's right side to the left of the screen. Sagittal images are displayed with the patient's head to the left of the screen. anterior anterior left Cephalad /cranial right Inferior / caudal posterior posterior

6. Role of Ultrasound •  To assess the: • Size • Capsular contour (smooth, coarse, lobulated) • Parenchymalechogenicity • Vascularity • Biliarytree • Masses or collections

7. Patient preparation: Elective hepatic scanning should be performed after an overnight fast or at least 6-8 hrs fasting which allows: • GB distension • Reduces portal vein caliber to its resting level • Reduces the amount of swallowed gas in the upper GIT

8. Patient position for liver • Right lobe: supine position /lateral decubitus with right side up. • Left lobe: Supine position • A liver ultrasound should include the following minimum images: • Longitudinal • Left lobe • Caudate lobe • IVC • Portahepatis • Comparison to RtKidney • Left hepatic vein • Transverse • Left lobe • Left portal vein • Right portal vein • Middle and Right hepatic vein

11. LEFT LOBE WITH LEFT HEPATIC VEIN

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