The purpose of this module is to introduce the tissue property filter concept as a way to understand how soft tissue contrast is obtained with MRI. A basic understanding of MRI is assumed. This includes the concepts of met magnetisation, longitudinal magnetisation recovery, transverse magnetisation relaxation, TR, TE, Spin Echo, Inversion Recovery, and Gradient Echo. These concepts are reviewed.

The module begins with the traditional overview of how tissue contrast is generated and identifies limitations of that paradigm. The concept of tissue property filters is introduced as an alternative.

Subsequent chapters describe tissue property filters for the different tissue properties used in MRI. We start with the filters for fast spin echo (FSE) proton density (PD), T1, and T2.
These chapters provide a foundation for understanding why traditional FSE PD, T1, and T2 “weighted” images look the way they do – specifically why some tissues appear dark and other tissues appear bright – and why some sequences are more sensitive for detecting pathology than others. We then introduce the T1 inversion recovery filter to explain how sequences like STIR, T2-FLAIR, and T1-FLAIR work and why they provider better contrast than traditional IR sequences.

Subsequent topics of diffusion, echo subtraction, and the concept of creating sequences with synergistic contrast are not yet developed. Synergistic contrast means that all the tissue properties work together to increase the sensitivity of the sequence for detecting pathology. Lastly, we will introduce sample sequences that should be very sensitive to pathology and explain how they work.

The app is designed for iOS devices. For optimal visualisation on a computer screen create a landscape shaped viewer window.

Text on the right hand side of the screen can be scrolled through using the mouse. Hyperlinks are indicated in blue. Graphs and buttons on the left hand side of the screen can be interacted with using the mouse or keypad.

Ultra-high contrast MRI papers

• Cornfeld D, Condron P, Newburn G, McGeown J, Scadeng M, Bydder M, Griffin M, Handsfield G, Perera MR, Melzer T, et al. Ultra-High Contrast MRI: Using Divided Subtracted Inversion Recovery (dSIR) and Divided Echo Subtraction (dES) Sequences to Study the Brain and Musculoskeletal System. Bioengineering. 2024; 11(5):441. 
• Newburn G, Condron P, Kwon EE, McGeown JP, Melzer TR, Bydder M, Griffin M, Scadeng M, Potter L, Holdsworth SJ, et al. Diagnosis of Delayed Post-Hypoxic Leukoencephalopathy (Grinker’s Myelinopathy) with MRI Using Divided Subtracted Inversion Recovery (dSIR) Sequences: Time for Reappraisal of the Syndrome? Diagnostics. 2024; 14(4):418. 
• Ma YJ, Moazamian D, Port JD, Edjlali M, Pruvo JP, Hacein-Bey L, Hoggard N, Paley MNJ, Menon DK, Bonekamp D, Pravatà E, Garwood M, Danesh-Meyer H, Condron P, Cornfeld DM, Holdsworth SJ, Du J, Bydder GM. Targeted magnetic resonance imaging (tMRI) of small changes in the T1 and spatial properties of normal or near normal appearing white and gray matter in disease of the brain using divided subtracted inversion recovery (dSIR) and divided reverse subtracted inversion recovery (drSIR) sequences. Quant Imaging Med Surg. 2023;13(10):7304-7337.
• Newburn G, McGeown J, Kwon E, Tayebi M, Condron P, Emsden T, Holdsworth S, Cornfeld D, Bydder G. Targeted MRI (tMRI) of Small Increases in the T1 of Normal Appearing White Matter in Mild Traumatic Brain Injury (mTBI) Using a Divided Subtracted Inversion Recovery (dSIR) Sequence. OBM Neurobiology. 2023;7(4):201.
• Ma Y, Moazamian D, Cornfeld D, Condron P, Holdsworth SJ, Bydder M, Du J, Bydder GM. Improving the Understanding and Performance of Clinical MRI using Tissue Property Filters (TPfilters) and the Central Contrast Theorem, MASDIR (Multiplied, Added, Subtracted and/or Divided Inversion Recovery) Pulse Sequences and Synergistic Contrast MRI (scMRI). Quantitative Imaging in Medicine and Surgery. 2022;12(9):4658-4690.

Conference Proceedings 

• Condron P, Kumar H, Holdsworth S, Cornfeld D, Bydder G. Multiple Sclerosis (MS): High Contrast Visualization of Abnormalities in Normal Appearing White Matter Using MASDIR Sequences. Oral Presentation, ISMRM, Toronto, Canada, 2023.
• Bydder M, Ali F. Validation of a High Contrast Technique and T1 Values Obtained by Divided Subtracted Inversion Recovery (dSIR). Abstract #3713, ISMRM, Singapore, 2024.
• Condron P, Newburn G, Kwon E, Emsden T, Bristow B, Tayebi M, Ngarimu T, Mohi W, Holdsworth SJ, Cornfeld D, Scadeng M, Bydder GM. Targeted MRI (tMRI) of Small Changes in the T1 of White Matter of the Brain in Methamphetamine Dependency Before and After Abstinence. Abstract #2505, ISMRM, Singapore, 2024.
• Condron P, Newburn G, Tayebi M, Kwon E, Griffin M, Scadeng M, Holdsworth SJ, Cornfeld D, Bydder GM. Recognition of Delayed Hypoxic Leukoencephalopathy After a Severe Drug Overdose Using a Divided Subtracted Inversion Recovery (dSIR) Sequence. Abstract #2526, ISMRM, Singapore, 2024.
• Condron P, Tayebi M, Emsden T, Bristow B, Ngārimu T, McHugh P, Newburn G, Taylor D, Holdsworth S, Cornfeld D, Scadeng M, Bydder G. MRI of Neuroinflammation in the Brain Following Meth Addiction Using Multiplied, Added, Subtracted and/or Divided (MASDIR) Sequences. Oral Presentation, ISMRM, Toronto, Canada, 2023.
• Condron P. Acquisition and Post Processing with Multiplied, Added, Subtracted and Divided Echo (MASDEA) Acquisition for Imaging Fascia. Oral Presentation, ISMRM, Toronto, Canada, 2023.