Bioluminescence imaging uses enzymes that emit light when reacting with a specific substrate. By introducing bioluminescent cells or organisms, the emitted light can be detected.

This technique is widely used in preclinical studies to track tumor growth, infections, and gene expression in living animals. Bioluminescence is highly sensitive and can detect small amounts of light, but it is mainly effective for monitoring processes in superficial tissues.

Fluorescence imaging uses fluorescently labeled molecules that absorb light at a specific wavelength and re-emit it at a longer wavelength. This fluorescence is detected by a camera, allowing the localization of specific molecules or cells in the body.                                                        

Fluorescence imaging is often used to track specific biological processes, such as tumor growth or the migration of immune cells. It is especially useful for surface imaging, although certain techniques allow imaging of deeper tissues as well.

Photoacoustics combines light and sound. When laser light is directed at tissue, some molecules absorb the light, causing thermoelastic expansion and the generation of ultrasound waves. These waves are detected and converted into images.

This technique is used for deep tissue imaging, commonly for studying blood oxygenation levels and vascular structures. It provides both functional and anatomical information and is used in oncological and cardiovascular research.

Ultrasound uses high-frequency sound waves that are reflected by tissues in the body. These reflected waves are captured by a transducer and converted into images of internal structures.

It is often used to image soft tissues such as the heart, liver, or embryos. In preclinical studies, ultrasound is a fast, non-invasive method to visualize anatomical changes and blood flow.

µCT is the preclinical version of CT-scans, using X-rays to create cross-sectional images of the body. By scanning the body from different angles, detailed 3D images are generated.

µCT provides high spatial resolution and is commonly used for imaging bone structures or lungs. It can also visualize vasculature or monitor changes in tissue structure in preclinical studies.

PET is similar to SPECT, but it uses positron-emitting radiopharmaceuticals. When these positrons collide with electrons in the body, photons (gamma rays) are produced and detected.

PET is mainly used to image metabolic processes, such as glucose metabolism or protein synthesis. This is highly useful in oncology, neurological, and cardiovascular preclinical studies. PET offers higher sensitivity than SPECT but is often more expensive.

In SPECT, radioactive substances (radiopharmaceuticals) are injected, which emit gamma rays. These gamma rays are detected by a gammacamera, and a 3D image of the radioactive substance distribution in the body is reconstructed.

SPECT is often used to visualize blood flow to organs such as the heart and brain. It provides functional information on physiological processes and is useful for studying cancer cells or metabolism in preclinical studies.

MRI uses a strong magnetic field and radio waves to create detailed images of tissues and organs. Water molecules in the body respond to the magnetic field, and by measuring these responses, a detailed image can be formed.

MRI provides excellent resolution for mapping soft tissues such as the brain, muscles, and organs. It is often used to study tumors, brain disorders, and cardiovascular abnormalities in preclinical research. A key advantage is that it does not use ionizing radiation, making it suitable for longitudinal studies.