Ultrasound — Sound Wave Imaging

Ultrasound, also known as sonography, relies on a small hand-held device called a transducer. The transducer emits inaudible sound waves into tissue and captures the echoes that bounce back from organs and masses. A computer processes these signals into real-time, two-dimensional or three-dimensional images.

Because different tissues, fluid collections, and tumours reflect sound differently, ultrasound clearly differentiates solid lesions from benign fluid cysts. Doppler ultrasound can also assess blood flow patterns within or around a growth, offering valuable diagnostic clues.

Ultrasound is often one of the first tests performed when a lump or pain appears. Because it happens in real time, doctors frequently use it to guide needles accurately during biopsies, ensuring tissue samples come directly from the suspicious area. This allows for a swift, reliable diagnosis while minimising procedural discomfort and complications.

While ultrasound itself does not measure molecular biomarkers, it is central to collecting them. It guides fine-needle aspirations or core biopsies that extract tissue for genomic, histological, and immunohistochemical testing (such as ER, PR, and HER2 in breast lesions). Specialised Doppler studies also test vascularity within suspicious lesions.

Ultrasound is widely used to evaluate breast changes, thyroid nodules, and testicular lumps. It is also routinely used to examine abdominal organs, helping detect primary liver cancer, gallbladder tumours, and pancreatic lesions. In gynaecology, pelvic and transvaginal ultrasound helps evaluate ovarian cysts, uterine masses, and endometrial thickening.

Ultrasound directly affects treatment planning by establishing tumour size, local spread, and involvement of adjacent blood vessels. Surgeons use intraoperative ultrasound during liver or brain resections to locate margins accurately. It also guides the placement of central venous catheters, drainage tubes for fluid build-up, and local ablative therapies.