Quantitative magnetic resonance imaging of subcutaneous adipose tissue.

Background/purpose: Quantitative transverse relaxation time (T(2)) magnetic resonance (MR) imaging has been used with the aim to characterize subcutaneous adipose tissue. Protons in adipose tissue have a fast exchange behavior giving bi-component transverse relaxation processes with short and long relaxation time values depending on the tissue properties.

Methods: MR images were acquired on a 1 T Siemens MR scan using a multi-spin-echo sequence.

Capillary permeability and extracellular volume fraction in uterine cervical cancer as patient outcome predictors: measurements by using dynamic MRI spin-lattice relaxometry.

Purpose: To improve the outcome prediction of uterine cervical carcinoma by measuring the vascular permeability (k(ep)) and the extracellular volume fraction (v(e)) of the tumor from Dynamic T(1)- IRM Relaxometry.

Materials And Methods: Twenty-six patients with proven cervical carcinoma were divided into good outcome and poor outcome groups. Classic tumor prognostic factors, the longest diameter L and the volume V of the tumor, were measured from morphologic MR images.

In vivo visualization of hyaluronic acid injection by high spatial resolution T2 parametric magnetic resonance images.

Background/purpose: In recent years, increasing use of injectable resorbable fillings has been reported for facial wrinkle treatment. However, the physiological processes involved such as the localization and subsequent diffusion of the injected product in skin tissues are poorly documented. This may be noninvasively achieved using quantitative magnetic resonance imaging (MRI), which is duly presented in this pilot study.

Magnetic resonance imaging measurements of vascular permeability and extracellular volume fraction of breast tumors by dynamic Gd-DTPA-enhanced relaxometry.

Vascular permeability (k(ep), min(-1)) and extracellular volume fraction (v(e)) are tissue parameters of great interest to characterize malignant tumor lesions. Indeed, it is well known that tumors with high blood supply better respond to therapy than poorly vascularized tumors, and tumors with large extracellular volume tend to be more malignant than tumors showing lower extracellular volume. Furthermore, the transport of therapeutic agents depends on both extracellular volume fraction and vessel permeability.

High spatial resolution quantitative MR images: an experimental study of dedicated surface coils.

Measuring spin-spin relaxation times (T2) by quantitative MR imaging represents a potentially efficient tool to evaluate the physicochemical properties of various media. However, noise in MR images is responsible for uncertainties in the determination of T2 relaxation times, which limits the accuracy of parametric tissue analysis. The required signal-to-noise ratio (SNR) depends on the T2 relaxation behaviour specific to each tissue.