The abdominal ultrasound transducer

A computer turns those echoes into moving images. The transducer remains outside the body for a standard abdominal examination, and it does not use ionising radiation.

Gel removes air between the transducer and skin because air interferes with transmission of sound. As the sonographer changes the probe's angle and position, different slices of organs appear on the screen. Returned echoes vary with tissue depth and character, producing the patterns used for interpretation.

The operator may select a probe or setting suited to the depth and area being assessed. Doppler settings can evaluate blood movement, while ordinary greyscale imaging outlines organs, stones, fluid, and other structural features. Image quality also depends on bowel gas and access to the target area.

Preparation may involve fasting or filling the bladder, so follow the booking instructions. During the examination, expose the requested area and tell the sonographer about any especially tender spot, recent wound, dressing, or difficulty changing position.

The probe is moved across the gelled skin with enough pressure to obtain a clear view. You may be asked to turn, take a deep breath, or hold your breath briefly so an organ shifts into view. Speak up if pressure becomes too uncomfortable; the operator can often alter the approach.

Mild pressure during scanning can occur, particularly over an already sore area. Sudden severe abdominal or back pain, fainting, repeated vomiting, a rigid or rapidly swelling abdomen, fever with pain, blood in vomit or stool, confusion, or difficulty breathing requires urgent assessment rather than waiting for the ultrasound result.

Before starting, ask which area will be scanned, whether you need a full bladder, and how long preparation restrictions continue. Mention mobility limitations or painful areas. For results, ask the referring clinician whether every target structure was adequately seen and what further step is planned if the images were limited.