T2vektet

T2vektet, or T2-weighted imaging, is a magnetic resonance imaging (MRI) sequence in which the image contrast predominantly reflects the transverse relaxation time, T2, of tissues. T2 is a property that describes how quickly transverse magnetization decays after a radiofrequency pulse due to spin-spin interactions. In practice, T2-weighted images are acquired with relatively long repetition times (TR) and long echo times (TE), which minimizes T1 effects and emphasizes differences in T2.

In T2-weighted images, tissues with longer T2 relaxation times retain signal longer and thus appear brighter. Fluids, such as cerebrospinal fluid and edema, typically show high signal intensity, while tissues with shorter T2 times appear darker. The appearance of gray matter and white matter can vary by region and sequence parameters, with fluids and pathologic fluid collections often standing out against the surrounding tissue. Fat may be suppressed or may contribute to signal depending on the protocol.

Clinical use: T2-weighted imaging is particularly useful for detecting pathology associated with increased water content, including edema, inflammatory processes, demyelinating diseases, tumors, and acute or subacute infarcts. It is also useful in musculoskeletal imaging to highlight edema in ligaments, cartilage, and muscles. T2-weighted images are commonly interpreted alongside T1-weighted images, FLAIR, and diffusion-weighted imaging to provide a comprehensive assessment.

Limitations and variations: Longer acquisition times and sensitivity to motion can affect image quality. Susceptibility and B0 inhomogeneities may degrade certain regions, especially near air-tissue interfaces. To improve contrast or lesion conspicuity, vendors offer variations such as fat suppression or fluid-attenuated techniques in conjunction with T2 weighting.