MRIsekvenssit

MRIsekvenssit refers to the specific protocols or sets of radiofrequency pulses and magnetic field gradients used in Magnetic Resonance Imaging (MRI) to generate contrast between different tissues. These sequences are crucial for highlighting specific anatomical structures or pathological processes. Different MRI sequences are designed to exploit variations in tissue properties, primarily the T1 and T2 relaxation times of water protons, as well as proton density.

Commonly used MRI sequences include spin echo (SE), gradient echo (GRE), and inversion recovery (IR). Spin echo sequences are known for their robustness and good signal-to-noise ratio, making them suitable for general anatomical imaging. Gradient echo sequences are faster and offer more flexibility in controlling image contrast, often used for dynamic imaging or when susceptibility artifacts are a concern. Inversion recovery sequences, such as STIR (Short Tau Inversion Recovery) and FLAIR (Fluid Attenuated Inversion Recovery), are particularly effective at suppressing signals from fat or fluid, respectively, which can enhance the visibility of certain lesions.

The choice of MRI sequence depends on the clinical question being asked and the specific area of the body being imaged. Factors such as the desired contrast, acquisition time, and susceptibility to artifacts influence the selection. Advanced sequences like diffusion-weighted imaging (DWI) and perfusion imaging provide information about tissue microstructure and blood flow, respectively, and are essential for diagnosing conditions like stroke and tumors. Understanding these sequences is fundamental to interpreting MRI results accurately.