Cerenkov Luminescence Imaging of Interscapular Brown Adipose Tissue

The overall goal of this procedure is to use Chernoff luminescence imaging to visualize brown adipose tissue with F 18 FDG. After demonstrating the feasibility of this methodology and nude mice by tail vein injection of F 18 FDG, the activation of brown adipose tissue is then monitored in vivo. Next spectral unmixing is used to remove unspecific chechen cough luminescence signal around the interscapular brown adipose tissue area, and then 3D tomographic imaging is used to visualize the tissue.

Ultimately, OV luminescence imaging can be used to visualize brown adipose tissue with F 18 FDG, particularly in laboratories without PET facilities. The main advantages of this technology over existing methods are it is easy to use, quick to perform inexpensive and widely available, particularly for image bro adipose tissue in mouse status. Before injecting the animals with F 18 FDG first place four anesthetized nude mice into the imaging apparatus and acquire a background image with the following parameters.

Open filter F equals one bin equals eight. Field of view equals D exposure time equals 120 seconds and stage temperature equals 37 degrees Celsius. Then intravenously inject the animals with 280 micro curry of F 18 FDG in PBS via the tail vein and return them to a cage equipped with food and water 30, 60 and 120 minutes after the injection.

Acquire the chernoff luminescence images with the same parameters as the background imaging. Then to quantify the signal to noise ratio, use the imaging software interface to draw two equal size ellipse regions of interest over the intrascapular brown adipose tissue, and an area adjacent to the brown pose tissue as a reference area to monitor brown adipose tissue activation after norepinephrine treatment, first IP inject one group of four nude mice with norepinephrine leaving a second group of nude mice unin injected as nonactivated controls. After 30 minutes iv, inject each mouse with 220 micro curie of F 18 FDG as just demonstrated, and then image both groups 60 minutes later, significantly higher.

Jaryn cough luminescence imaging signal is expected under norepinephrine treatment than in controls for multi cough luminescence tomography studies after injecting 300 micro curry of F 18 FDG acquire multispectral images at 60 minutes after injection. From the animal's dorsal side with the following parameters, F equals one bin equals 16. Acquisition time equals 300 seconds per filter and emission filters equals five hundred eighty six hundred six hundred and twenty six hundred and forty, six hundred and sixty and 680 nanometers.

The acquisition will take about 30 minutes for completion. Then conduct spectral unmixing with living imaging, 4.3 0.1 software and then from the tool palette panel, select the spectral unmixing button and press analyze, then select automatic from the pull down method manual. Finally, apply the ticoff regularization in the non-negative lease squares optimization of the residuals to generate the surface tomography, which is used for 3D image co-registration from the structure light imaging.

In this image, no particular area was highlighted from the unmixed image of the number one component and the corresponding spectrum closely resembles the emission spectrum of the F 18 in pure media. These signal suggests that the unmixed number one represented an unspecified chernov luminescence image signal, which is probably from very shallow depths such as from F 18 FDG accumulation in the skin. The peak of the unmixed number two spectrum was around 640 nanometers, suggesting that the signal was from the brown adipose tissue.

Interestingly, contrary to the significant attenuation of the intensity of the chernov luminescence image shorter than 640 nanometers, no dramatic decrease of the intensity was observed once it reached its peak indicating a better tissue penetration of the emitted light At longer wavelengths. The reconstructed 3D images acquired with Multispectral Senoff luminescence tomography are coregistered with surface tomography that is generated from the structured light, and the images reveal that a substantial portion of the chernov luminescence image signal originates from the intrascapular brown pose tissue. Remarkably, the coronal image clearly outlines the two lobes of the brown pose tissue, which closely resembles the triangle contour of the brown pose tissue shown in this macro anatomical image.

After watching the video, you should be able to apply this image procedure to other image studies of brown adipose tissue.