The Preclinical MRI Core Faciltiy runs MR spectroscopy or imaging experiments on an hourly fee basis. We will be happy to discuss how MR imaging can be used to further your research goals.

Standard applications of the lab include anatomic, T1, T2, diffusion, and perfusion studies. In addition, global and localized spectroscopy experiments are available for either proton or multinuclear applications. Cultured tissue, excised organ, and in vivo model systems are utilized in the following ongoing studies:

In Vivo Imaging

Anatomic in vivo imaging is routine in the head, thorax, and abdomen. Shown are a mouse brain and kidney.

In Vivo Imaging In Vivo Imaging

Angiography

Angiographic images can also be obtained with flow compensated gradient echo imaging. On the right is a 3 dimensional image of the vessels in a rat head.

Angiography

Calculated Parameter Images

In some circumstances, calculated parameter images are desired. In the example shown below, a T1 calculated image of cartilage demonstrates substantial variation in T1 in the presence of Gd(DTPA).

Calculated Parameter Images

Arterial Spin Labeling

Perfusion weighted imaging via arterial spin labeling is also available. In the example shown below, the first image is an image obtained with saturation of the spins (blood) in the neck region, leading to saturation in the perfused area of the brain. The second image is the "control". A calculated image is shown on the far right.

Arterial Spin Labeling Arterial Spin Labeling Arterial Spin Labeling

In Vivo Mouse Cardiac Imaging

Mouse cardiac imaging can be done on a vertical bore 8.5Tesla MRI system or a horizontal bore 4.7Tesla system. Due to the ease of positioning and the lower respiratory motion on the horizontal system, we currently are pursuing most of the cardiac imaging on the 4.7T instrument.

Cardiac images can be obtained in both systole and diastole. The myocardium in each section can be identified and planimetry used to determine the volume of myocardium in each slice. The specific gravity of myocardium was used to convert volume to mass. Ejection fractions can be computed from diastolic and systolic images.

In Vivo Mouse Cardiac Imaging In Vivo Mouse Cardiac Imaging

Images can be obtained throughout the cardiac cycle to produce cine loops of cardiac motion.

In Vivo Mouse Cardiac Imaging In Vivo Mouse Cardiac Imaging In Vivo Mouse Cardiac Imaging

Figures 3. Direct flow studies can be used to visualize flow within the heart. Fast segmented gradient echo sequences with relatively high flip angles can be used to highlight flow; regurgitant flow results in a signal void.

Cultured Tissue

Cultured Tissue

Small (approximately 2 mm) cartilage samples can be imaged with isotropic 50 micron resolution. In the images on the left, a 3D data set is obtained of a cartilage sample; above left is the proton density image demonstrating homogeneous tissue with small blood vessels. Above right is a T1 weighted 3D image demonstrating striking T1 variations across the sample. Bottom left is one 2D section from the 3D data set, demonstrating good correspondence with histology (bottom right).

 

Isolated Organs:

Isolated Organs:

Isolated organs can be imaged in 3D to demonstrate the internal anatomic structures which are difficult to view with 2D histologic slides; on the right is an isolated mouse heart; below left is a mouse knee; below right is an isolated kidney.

Isolated Organs: Isolated Organs: