T2viktad

T2viktad is the term used in Swedish radiology to describe T2-weighted magnetic resonance imaging (MRI) sequences. It refers to a class of MRI contrast mechanisms in which differences in T2 relaxation times across tissues are emphasized, making fluids and edema appear bright while many other tissues are relatively darker.

Principles and appearance. In a T2-weighted sequence, the imaging parameters are chosen to maximize T2 contrast, typically with a long echo time and a long repetition time. This weighting tends to suppress T1 effects and highlight differences in water content. On the resulting images, cerebrospinal fluid and edema commonly appear bright, while normal white matter is darker and gray matter shows intermediate signal. Fat signal can vary depending on the exact sequence and may require fat suppression in some protocols.

Clinical uses. T2viktad imaging is widely used for examining the brain, spine, joints, and various organs. It is particularly useful for identifying edema, cysts, inflammatory or demyelinating lesions, tumors, ischemic changes, and other conditions associated with increased water content. In brain imaging, it helps visualize pathology adjacent to CSF and can complement T1-weighted imaging. In the spine and musculoskeletal system, it aids in detecting disc herniation, nerve root compression, and inflammatory or traumatic changes.

Variants and related sequences. Common variants include turbo or fast spin-echo T2 sequences, which shorten acquisition time. Fat-suppressed or water-only T2 protocols can improve lesion conspicuity. Fluid-attenuated inversion recovery (FLAIR) is a related technique that suppresses CSF signal to enhance certain periventricular lesions.

Limitations. T2 weighting can have lower spatial resolution and is more susceptible to motion, with fat signals potentially obscuring subtle abnormalities. It is typically used in combination with other MRI sequences to provide a comprehensive assessment.