DSC Perfusion MRI Artefact Reduction Strategies: A Short Overview for Clinicians and Scientific Applications

Abstract

MRI perfusion is used to diagnose and monitor neurological conditions such as brain tumors, stroke, dementia, and traumatic brain injury. Dynamic Susceptibility Contrast (DSC) is the most widely available quantitative MRI technique for perfusion imaging. Even in its most basic implementation, DSC MRI provides critical hemodynamic metrics like cerebral blood flow (CBF), blood volume (CBV), mean transit time (MTT), and time between the peak of arterial input and residue function (Tmax), through the dynamic tracking of a gadolinium-based contrast agent. Notwithstanding its high clinical importance and widespread use, the reproducibility and diagnostic reliability are impeded by a lack of standardized pre-processing protocols and quality controls. A comprehensive literature review and the authors' aggregated experience identified common DSC MRI artefacts and corresponding pre-processing methods. Pre-processing methods to correct for artefacts were evaluated for their practical applicability and validation status. A consensus on the pre-processing was established by a multidisciplinary team of experts. Acquisition-related artefacts include geometric distortions, slice timing misalignment, and physiological noise. Intrinsic artefacts include motion, B₁ inhomogeneities, Gibbs ringing, and noise. Motion can be mitigated using rigid-body alignment, but methods for addressing B₁ inhomogeneities, Gibbs ringing, and noise remain underexplored for DSC MRI. Pre-processing of DSC MRI is critical for reliable diagnostics and research. While robust methods exist for correcting geometric distortions, motion, and slice timing issues, further validation is needed for methods addressing B₁ inhomogeneities, Gibbs ringing, and noise. Implementing adequate mitigation methods for these artefacts could enhance reproducibility and diagnostic accuracy, supporting the growing reliance on DSC MRI in neurological imaging. Finally, we emphasize the crucial importance of pre-scan quality assurance with phantom scans.

Keywords: artefacts; dynamic susceptibility contrast; perfusion weighted imaging; pre-processing.

Figure 1

Normalized Dynamic Susceptibility Contrast (DSC) MRI signal of a 3 × 3 × 3 mm³ cube region located in healthy brain tissue (region indicated by the red box). Normalization was the division of observed signal intensity by max observed signal intensity.

Figure 2

Geometric distortions in DSC MRI appear as misshapen or incorrectly sized brain structures, leading to spatial misregistration with anatomical images, primarily in regions near air/tissue interfaces. Geometric distortions in DSC MRI arise due to B₀ field inhomogeneities and tissue susceptibility differences. On the left is a T₁w MRI scan and on the right a DSC MRI scan with visible geometric distortions. The red square indicates tissue hyper intensities due to B₁ field inhomogeneities.

Figure 3

B₁ field inhomogeneity in DSC MRI appears as spatially varying signal intensities. The red square indicates tissue hyper intensities due to B₁ field inhomogeneities.

Figure 4

Subject motion causes image blurring and may lead to stripes in the phase encoding direction. Top panel is DSC acquisition without motion, bottom panel is DSC acquisition with motion.

Figure 5

Normalized DSC MRI signal of a 3 × 3 × 3 mm³ cube region (indicated by the red box), demonstrating the presence of motion artefacts. Distinct peaks labeled “Motion” indicate signal disruptions caused by patient movement. Normalization was the division of observed signal intensity by max observed signal intensity.

Figure 6

Normalized DSC MRI signal of a 3 × 3 × 3 mm³ cube region (indicated by the red box), illustrating substantial noise artefacts. The fluctuating pattern indicates physiological noise. Normalization was the division of observed signal intensity by max observed signal intensity.