A major challenge of T1 and T2 mapping in MR Imaging is that rapid methods must be used to acquire the data required to create the maps in a relatively short scan time, otherwise the data will reflect substantial artifacts from cardiac and respiratory motion. However, these rapid methods are affected by multiple confounding factors that lead to bias and poor reproducibility in quantitative measurements. This leads to differences caused by protocol-dependent, vendor-dependent, hardware- and software-dependent, and even site- and system-dependent bias in the apparent T1 and T2 measurements. Such inconsistency between data acquired at a different time and/or a different location undermines clinical utility.
UW-Madison researchers and collaborators have developed a system to improve reproducibility and accuracy when mapping tissue properties across different MR imaging systems, vendors, protocols, and sites. It provides confounder-corrected tissue mapping by correcting for the impact of confounding effects on tissue properties, such as T1 and T2 measurements, or others from CT data.
The method includes determining ground truth values for a phantom that includes compartments with known reference values for at least one tissue property. Then acquiring apparent values for the tissue property using a clinical imaging protocol. Correction data is generated by processing the apparent values and the ground truth values using a model. The correction data is used to correct apparent values acquired from a subject using the clinical imaging protocol to generate corrected values of the tissue property.