Hand-held and point-of-care ultrasound

What it does. Conventional ultrasound machines are cart-sized and priced for radiology departments. Since GE's Vscan in 2010, and especially since Butterfly Network replaced the piezoelectric crystal array with a silicon chip in 2017, a whole-body probe fits in a pocket, runs off a phone or tablet, and stores images to the cloud. Philips Lumify, Clarius and others sell wireless or plug-in probes; image quality is below a departmental machine but adequate for many questions.

Where it matters in cancer. Triage of breast lumps where mammography is scarce; measuring thyroid nodules and neck nodes; finding liver masses and ascites; guiding biopsies, drains and central lines at the bedside; checking for kidney obstruction in cervical or bladder cancer; and in palliative care, confirming effusions before drainage. In low- and middle-income countries, where most of the world's cancer patients live and where imaging is the largest single gap in diagnosis, a hand-held probe with a trained nurse and a tele-radiology link is often the only imaging within reach. Butterfly and the Bill and Melinda Gates Foundation deployed thousands of probes to sub-Saharan Africa primarily for maternal care, and the same devices serve cancer clinics.

What changes and what limits it. A normal scan lets the clinic reassure and discharge; a suspicious scan justifies the journey to a biopsy or CT. Accuracy depends on the operator, training programmes are short, and a small probe cannot replace mammography, CT staging or a radiologist's report. Regulation covers the devices (FDA clearance and CE mark for the major brands) rather than the person holding them. Costs run from about two thousand to ten thousand pounds per probe plus a subscription for software and cloud storage, roughly a tenth of a cart machine.