Special probes improve ultrasound for people with obesity

Ultrasound is used to diagnose many diseases in the abdominal cavity. A recent study conducted by Leipzig University Medicine with the support of the Helmholtz Institute for Metabolism, Obesity and Vascular Research (HI-MAG) shows that obesity impairs the quality of ultrasound in liver and kidney examinations. It also shows that the use of high-performance probes can improve the anatomical visualisation of ultrasound images in these patients. The results have been published in the journal "Scientific Reports".

The ultrasound examination of the abdominal organs plays a central role as a diagnostic tool and is recommended as the first measure for many complaints. Compared to other imaging procedures, such as computer tomography (CT) and magnetic resonance imaging (MRI), ultrasound is easily available, avoids unnecessary radiation exposure and can be used on almost anyone. However, the accuracy of this method is usually limited in people who are overweight, as anatomical structures are more difficult to visualise. However, it has not yet been sufficiently researched at what degree of obesity ultrasound diagnostics is no longer sufficiently precise.

In a recent clinical study at Leipzig University Medicine, researchers found that the quality of ultrasound in liver and kidney examinations is significantly impaired in patients with obesity. „The results showed that the higher the body mass index of the participants, the poorer the image quality of the ultrasound. It also became clear that modern ultrasound probes with so-called matrix technology improve the quality of the ultrasound image," explains Prof Dr Thomas Karlas, head of the study and corresponding author of the current publication. The matrix probes have improved transmission and reception technology and therefore achieve a greater penetration depth into the tissue. This means that better diagnostic accuracy can be achieved in high-risk patients. To date, there has not been sufficient scientific confirmation of the performance of the matrix probes in people who are overweight.

The current data show that the relatively expensive special probes for ultrasound devices can offer relevant added value. The 40 participants in the study underwent a highly standardised ultrasound examination of the abdomen with three different probes, a standard probe versus two high-performance probes. The liver and right kidney were examined in people with different degrees of obesity. The quality of the ultrasound examination was assessed using a point score.

„Especially at centres that specialise in the care of patients with obesity, for example in the field of diabetology, nutritional medicine or obesity surgery, ultrasound devices with matrix probes should be available for the examination of the abdominal cavity,

recommends Prof. Karlas. The senior physician and head of the interdisciplinary central ultrasound unit at the Clinic and Polyclinic for Oncology, Gastroenterology, Hepatology and Pneumology at Leipzig University Hospital also points out the following problem: „Even if matrix probes improve the ultrasound quality in obesity, the quality that was determined in lean comparison subjects is often not achieved. Obesity therefore remains a challenge - both as a cause of secondary diseases, for example metabolic liver disease, but also as a limitation of common diagnostic methods. A follow-up project will investigate whether specialised ultrasound applications, such as the determination of liver fat content and liver stiffness, work better with the high-performance probes than with conventional methods.

Original publication in Scientific Reports:

"The application of high-performance ultrasound probes increases anatomic depiction in obese patients." Doi: https://doi.org/10.1038/s41598-023-43509-9

Information on the collaboration with HI-MAG:

The Helmholtz Institute for Metabolism, Obesity and Vascular Research (HI-MAG) is a joint institution of Helmholtz Munich with the Medical Faculty of Leipzig University and Leipzig University Hospital. The institute investigates the molecular basis of morbid obesity in order to enable precise therapies for obesity and its secondary diseases with the help of a clinical-translational research approach.

For the current study, HI-MAG provided the Interdisciplinary Ultrasound Department of Leipzig University Hospital with a modern ultrasound device with matrix probes. In addition, Dr Sascha Heinitz, an employee of HI-MAG, was able to visit the ultrasound centre and carry out the study presented. These structural requirements are a unique selling point for Leipzig University Medicine.

News of the "Universität Leipzig" from 16 October 2023