Project: Morphological MRI Investigation of Subcutaneous Adipose Tissue in Lipedema Patients

Principal Investigator: Philipp Kruppa, MD
Co-Principal Investigator: Alexander Huppertz, MD, PhD
Co-Principal Investigator: Mojtaba Ghods, MD, PhD
Klinikum Ernst von Bergmann gGmbH
Department of Plastic, Aesthetic and Reconstructive Microsurgery/Hand Surgery
Potsdam, Germany

Summary

Foremost, the project is aiming to develop a standardized MR protocol for the reliable diagnosis of Lipedema. In particular, differences between healthy probands and Lipedema patients at different stages of the disease will be compared. In addition, qualitative and quantitative parameters are compared between different body regions (abdomen and lower extremity). Furthermore, this study investigates the long-term response of the parameters studied after surgical treatment (liposuction) performed on affected extremities.

Background

For Lipedema patients, MR studies of the subcutaneous adipose tissue (SAT) described a homogeneous thickening of the subcutis in the absence of free fluid. The fat-to-water ratio in the Dixon sequence is found to be increased in Lipedema patients. In addition, an increased sodium concentration is found in skin and SAT compared to healthy controls. Furthermore, excessive fat volumes in the intramuscular and intermuscular compartments have been demonstrated for lymphedema patients, although this aspect has not been adequately studied for patients with Lipedema so far.

Our study will significantly improve knowledge on three aspects:

1) The validation of the results of the Vanderbilt University Medical Center research group in an independent European setting regarding intradermal and SAT sodium concentrations.

2) The objective, software-based quantification of intramuscular and intermuscular fat content in Lipedema patients compared to healthy controls.

3) The influence of surgical therapy (liposuction) on long-term response of potential MR diagnostic criteria in Lipedema patients.

Methodology

The aim of this study is to perform a comparison of morphological, volumetric, and functional MRI parameters of Lipedema patients vs. (healthy) controls. In the study, 21 Lipedema patients (7 patients each in stage I, II, and III), and 21 control subjects matched for sex, age, and BMI will be examined by MRI. For the Lipedema collective, a follow-up MRI examination will be performed after completed surgical therapy (usually 2-4 lower extremity surgeries) and an additional convalescence interval of 6 months. An MRI sequence of the abdomen and the dominantly affected extremity is conducted in each patient. In each case, a T1, T2, Dixon, as well as a specific sodium imaging sequence is performed. Volumetric data are quantified using specialized software solutions.

Study objectives were defined as intradermal and SAT sodium concentrations, volume fractions of intramuscular and intermuscular adipose tissue, presence of lymphostasis markers, and SAT fat-to-water ratio. The collected data will be correlated to the severity of Lipedema-associated symptoms and compared with healthy subjects. Additionally, the data will be analyzed for differences between different body regions (abdomen and extremities), between different disease stages, and for changes after surgery.

Expected outcomes

The hypothesis is that in Lipedema-affected regions (thighs), the following parameters will compare with the (unaffected) periumbilical region or the thighs of a healthy reference population as follows: (1) increased sodium concentration (intradermal and subcutaneous), (2) no differences in lymphostasis markers, (3) increased volume proportions of intramuscular and intermuscular adipose tissue, and (4) increased fat-to-water ratio of subcutaneous tissue. Furthermore, it is hypothesized that the studied parameters in Lipedema patients will trend towards baseline data of the healthy reference population after completion of surgical therapy (usually 2-4 lower extremity surgeries) and an additional convalescence interval of 6 months.

Practical implementations of results

The main limitation in targeted care of Lipedema patients is the lack of an independent and distinct diagnosis validation tool. MRI technology matches these criteria and could therefore be a useful addition to current routine clinical diagnostics. The results of our research will have a relevant impact on the further development of a standardized MR protocol for the diagnosis of Lipedema with sufficient reliability and reproducibility. Considering the limited absolute sample size, this study aims to provide the basis for implementing a protocol based on less cost-efficient techniques with wide availability.

Our Research Grantees by:   Topic | Recent Projects | Past Projects

LF38_21