The Latest in Imaging: Photoacoustics

Imagine being able to image lesions below the skins surface in 3D, or visualising the network of blood vessels into which you are about to cannulate.

Photo-acoustic imaging technology had been in use in academia for years. Now various companies are in the process of commercializing it. The approach provides optical imaging quality at the depth of ultrasound and can view different tissues without contrast media such as iodine. 

How does it work? Photoacoustic imaging is a hybrid biomedical imaging modality based on the photoacoustic effect. Laser pulses are delivered into biological tissues where

 it is absorbed and converted into heat, leading to transient thermoelastic expansion and ultrasonic emission. The generated ultrasonic waves are then detected by

 ultrasonic transducers to form images. 

Here are some examples of its application:

1. 3D imaging of a melanoma in-vivo (right)

2.  Thermoacoustic image of a mastectomy specimen (left).

The malignant breast tissue generates a much stronger thermoacoustic signal than the surrounding benign tissue due to its high microwave absorption.