Sample Images

Magnetic resonance imaging (MRI) is a widely used modality for visualizing organs, tissues, and dynamic proceses within the body. Using only magnetic fields, an MRI scanner produces images representing essentially the distribution of atoms exhibiting nuclear magnetic resonance, such as hydrogen. In addition to the simple density of these atoms, MRI can achieve a wide variety of image contrasts based on the local chemical environment, motion, flow, etc.

Below is a brief image gallery.


The collected raw data signals represent the spatial frequency content of the object being imaged. In all MR reconstruction, samples from the (left) frequency domain are inverse Fourier transformed to form images in the (right) object domain.

Practical imaging is complicated by several factors which will become clear during the course. These imperfections include: 1) off-resonance (where not all of the spins in the body is resonating at the same frequency), 2) flow or motion (where spins do not remain stationary during the imaging process), 3) relaxation of excited spins, and 4) hardware imperfections. These produce artifacts that should be understood in both the spatial frequency domain and object domain.

Below are some examples of clincally useful images that can be acquired using the latest MRI techniques.


A high resolution image of the left coronary artery (LCA) and branches in a healthy volunteer. This was acquired during a 16-second breath-hold. The smallest of the visible vessels are barely 1 mm in diameter!


Standard clinical knee image showing an anterior cruciate ligament (ACL). The ACL appears darker relative to surrounding tissue.


Here we are imaging the left ventricle and aorta in real-time using a Spiral SSFP sequence. The thick muscular chamber on the left is the left ventricle (LV). Two leaflets can be seen in the middle of the image, and are barely opening. A flow jet, with signal enhancement, can also be seen through the leaflets. The stiff movement of valve leaflets and tightness of the flow jet are indicative of valvular disease.


This is a cross-sectional view through the aortic valve in a patient. Color is used to display through-plane velocities. The aortic valve in most people has three cusps, and when it becomse stiff (like in this aortic stenosis patient), aortic outflow can become very fast, up to 5 meters/s, and resembles a "mercedes" pattern.