Final answer:
Magnetic Resonance Imaging (MRI) is the imaging technique used to suppress CSF and diagnose periventricular disease and infarct lesions in the cord.
Step-by-step explanation:
The imaging technique that suppresses cerebrospinal fluid (CSF) to help diagnose periventricular disease and infarct lesions in the cord is Magnetic Resonance Imaging (MRI). MRI is highly valued for its ability to produce detailed images without the use of ionizing radiation, which can be particularly important for patients with potential brain or spinal cord issues. This medical imaging tool operates on the principles of nuclear magnetic resonance, interacting with hydrogen nuclei in the body to create two-dimensional and three-dimensional images of the body's internal structures.