3D T 1-mapping for the characterization of deep vein thrombosis

Abstract

Measurement of all relevant T (1) values of acute thrombi and normal blood achieved accurate and reproducible results in vivo. Fast T (1) quantification of the thrombus can provide information about tissue characteristics such as thrombus resolution. Such a quantitative MRI technique may be valuable in studying the factors that influence natural resolution and in evaluating treatment effects that enhance this process.

In Vivo Magnetization Transfer and Diffusion-Weighted Magnetic Resonance Imaging Detects Thrombus Composition in a Mouse Model of Deep Vein Thrombosis

“…Proton binding to Fe 3+ within accumulating methemoglobin in the thrombus is thought to result in shortening of the T1 and T2 relaxation times. 20,21 The protein content of thrombus cannot, however, be directly detected using conventional MRI owing to the very short T2 relaxation times (<0.1 millisecond) of restricted protons bound to proteins. The development of fibrin-targeted MR contrast agents has allowed in vivo imaging of the fibrin content in arterial and venous thrombus in animal models and humans.…”

“…21 The 2 imaging trains result in a set of 16 images per slice with increasing inversion times. For T1 mapping, the acquisition parameters were TR=9.6 milliseconds, TE=4.9 milliseconds, flip angle=10°, FOV=36×22×10 mm, acquired matrix=180×102, measured slice thickness=0.5 mm, acquired resolution=0.2×0.2 mm, reconstructed resolution=0.1×0.1 mm, slices=20, and averages=1.…”

A new method for quantification of false lumen thrombosis in aortic dissection using magnetic resonance imaging and a blood pool contrast agent

“…DTI is a technique that relies on the intrinsic properties of thrombus to produce signal enhancement on MR. [16][17][18][19][20] We have used it as supportive evidence to validate distribution of the blood pool contrast agent and found good agreement between both the DTI and phase-contrast flow data. DTI has potential to be used as the sole technique to quantify thrombus, but at present is limited by low spatial resolution and relatively long acquisition times; further development and investigation is planned.…”

“…Direct thrombus imaging (DTI) is technique that uses endogenous properties of thrombus (methemoglobin content) to produce a bright signal on black blood imaging. [16][17][18][19][20] DTI images were acquired before administration of exogenous contrast agent, using an electrocardiogram-triggered, 3D gradient echo sequence with an effective inversion time chosen to null the blood (FOV, 300 ϫ 255 ϫ 60 mm 3 ; acquired voxel size, 2 ϫ 2 ϫ 5 mm 3 ; flip angle, 15°; TR/TE, 3.2/0.94 ms; TI, 490 ms; TFE factor, 36). Fat suppression was applied to null fat signal to avoid chemical shift artefacts.…”

European Perspectives

“…He says, "Ten years later, we developed this method by creating a T1 mapping sequence that allowed rapid analysis of longitudinal T1 time of a thrombus in man. 4 This revealed a shortening of T1 time as the thrombus resolved, but the source of the signal and its relationship to the structure of the thrombus were not known. We went back to our experimental model of thrombosis, in which we could relate T1 signal at any given time to the structure of a thrombus visualised histologically.…”