A key characteristic of intrinsic contrast parameters in tissues is that they are specific to each tissue type. This specificity allows MRI to differentiate between various tissues based on their unique properties, such as water content, cellularity, and molecular composition. For instance, the differences in relaxation times (T1 and T2) between fat and water can be exploited in MRI imaging to provide contrast and detail in the resulting images. These characteristics are inherent to the tissues themselves and help radiologists identify and assess different structures or abnormalities within the body.
The other concepts presented are important to understand in the broader context of MRI but do not define intrinsic contrast parameters. Altering contrast parameters during imaging refers to the use of different imaging techniques or sequences, while stating that they are uniform across all tissues contradicts the fundamental principle of MRI that relies on the differences between tissues. Lastly, while patient factors can influence overall imaging results, intrinsic contrast parameters focus on the physical and chemical properties of the tissues themselves rather than variations between patients.