Functional magnetic resonance imaging (fMRI) has emerged as an essential and highly valuable tool within the neuroscience toolkit, offering noninvasive and high-resolution insights into the functional architecture of the brain. We introduce an advanced line-scanning fMRI protocol that achieves exceptional spatiotemporal fidelity, enabling layer-specific mapping of neuronal circuitry with high precision. Furthermore, single-vessel fMRI is highlighted as a powerful approach for resolving hemodynamic signals at the level of individual microvessels, providing valuable insights into the complex neurovascular coupling mechanisms. These imaging strategies, when combined with optogenetic control and fiber photometry readouts, allow for precise circuit-level manipulation and simultaneous recording, establishing a causal framework for understanding brain function. In conclusion, these cutting-edge fMRI techniques represent a major methodological milestone in functional neuroimaging, opening new avenues for high-resolution and multimodal exploration of the living brain.