What does the 20-MHz ultrasound show?

The layers of the skin, the skin appendages and structures directly beneath the skin. Tumours and inflammations show typical images, and the thickness of a lesion can be measured.

Why is the tumour thickness measured before an operation?

How deep a tumour reaches determines how the procedure is planned and which further steps make sense. The ultrasound provides this value before the procedure; it is checked on the removed tissue under the microscope.

Is the examination painful?

No. It is non-invasive and as a rule causes little pain; you merely feel the probe and the gel on the skin.

Does the ultrasound replace a tissue sample?

No. The ultrasound helps to classify a lesion and to plan a procedure. Whether it is benign or malignant is, where necessary, still settled by the examination under the microscope.

Does health insurance cover the costs?

20-MHz ultrasound is as a rule one of the self-pay or IGeL services. We discuss beforehand what makes medical sense in your case and which framework applies.

20-MHz ultrasound (skin sonography)

High-resolution sonography of the skin: non-invasive and imaging. Before an operation we use it to determine how deep a tumour reaches.

Overview

20-MHz sonography is a non-invasive imaging method for diagnosis. It shows the skin and the skin appendages, that is hair, nails and the sebaceous and sweat glands, in detail. With a resolution of about 80 µm axially and 200 µm laterally, fractions of a millimetre, even fine structures in and beneath the skin can be assessed.

Many skin diseases, among them tumours and inflammations, show typical images on high-resolution ultrasound. The examination therefore provides additional information that supports the distinction between different skin lesions. It complements inspection with the naked eye and dermoscopy (incident-light microscopy), but does not replace them.

One focus lies on the time before an operation: with a skin tumour we use the ultrasound to measure the depth of invasion, that is the thickness of the tumour. This value determines how the procedure is planned and which further steps make sense. In our practice, 20-MHz sonography is therefore part of skin cancer screening.

Areas of application

Measuring the tumour thickness (depth of invasion) before a planned operation
Assessing unclear skin lesions as an addition to inspection and dermoscopy
Distinguishing between tumorous and inflammatory skin lesions
Assessing structures in and beneath the skin that cannot be judged from the outside
Addition to skin cancer screening

Procedure

Clarifying the question
At the start we discuss what the ultrasound is meant to clarify: the thickness of a tumour before the operation, or how an unclear skin lesion should be classified. The examination usually follows on from the inspection and the dermoscopy.
Examination with the probe
A little contact gel is applied to the area of skin in question, then the probe is placed on it. The image appears in real time on the monitor. The examination is non-invasive; the skin remains intact.
Measuring and assessing
On the image we measure the depth of a lesion and assess how it is delimited from the surrounding tissue. Tumours and inflammations show typical patterns, which we interpret together with the clinical picture.
Discussing the findings
We discuss the result with you and derive the next steps from it, from monitoring over time through to planning a procedure. If an operation is due, the measured tumour thickness goes into its planning.

What to expect

The examination is non-invasive and as a rule causes little pain; you feel the probe and the cool gel on the skin.
Ultrasound works with sound waves and needs no X-rays; the examination can be repeated where necessary.
As a rule no special preparation is needed.
The image is produced during the examination; we discuss the result with you.
20-MHz sonography is usually combined with inspection, dermoscopy and other methods of skin cancer screening.
20-MHz sonography is as a rule a self-pay or IGeL service; we discuss the framework with you beforehand.

Risks & notes

The examination itself is non-invasive and carries no notable risks.
No diagnostic method offers 100 per cent certainty. The ultrasound supports the medical assessment but does not replace it.
The tumour thickness measured by ultrasound is an estimate before the procedure. It is determined definitively by examining the removed tissue under the microscope (histology).
If a finding gives cause for concern, surgical removal with a subsequent examination under the microscope may be necessary in order to establish a reliable diagnosis.
Like every imaging method, 20-MHz ultrasound has limits, for example with lesions lying very deep; where necessary we add further examinations.

Frequently asked questions

What does the 20-MHz ultrasound show?: The layers of the skin, the skin appendages and structures directly beneath the skin. Tumours and inflammations show typical images, and the thickness of a lesion can be measured.
Why is the tumour thickness measured before an operation?: How deep a tumour reaches determines how the procedure is planned and which further steps make sense. The ultrasound provides this value before the procedure; it is checked on the removed tissue under the microscope.
Is the examination painful?: No. It is non-invasive and as a rule causes little pain; you merely feel the probe and the gel on the skin.
Does the ultrasound replace a tissue sample?: No. The ultrasound helps to classify a lesion and to plan a procedure. Whether it is benign or malignant is, where necessary, still settled by the examination under the microscope.
Does health insurance cover the costs?: 20-MHz ultrasound is as a rule one of the self-pay or IGeL services. We discuss beforehand what makes medical sense in your case and which framework applies.