5 September 2019

In Plos One, Florieke Eggermont, Esther Tanck and colleagues developed a calibration method, which makes clinical implementation of CT-based finite element models as tool for fracture risk assessment easier.
 
Abstract
The objective of this study was to develop a new calibration method that enables calibration of Hounsfield units (HU) to bone mineral densities (BMD) without the use of a calibration phantom for fracture risk prediction of femurs with metastases using CT-based finite element (FE) models. Fifty-seven advanced cancer patients (67 femurs with bone metastases) were CT scanned atop a separate calibration phantom using a standardized protocol. Non-linear isotropic FE models were constructed based on the phantom calibration and on two phantomless calibration methods: the "air-fat-muscle" and "non-patient-specific" calibration. For air-fat-muscle calibration, peaks for air, fat and muscle tissue were extracted from a histogram of the HU in a standardized region of interest including the patient's right leg and surrounding air. These CT peaks were linearly fitted to reference "BMD" values of the corresponding tissues to obtain a calibration function. For non-patient-specific calibration, an average phantom calibration function was used for all patients. FE failure loads were compared between phantom and phantomless calibrations. There were no differences in failure loads between phantom and air-fat-muscle calibration (p = 0.8), whereas there was a significant difference between phantom and non-patient-specific calibration (p<0.001). Although this study was not designed to investigate this, in four patients who were scanned using an aberrant reconstruction kernel, the effect of the different kernel seemed to be smaller for the air-fat-muscle calibration compared to the non-patient-specific calibration. With the air-fat-muscle calibration, clinical implementation of the FE model as tool for fracture risk assessment will be easier from a practical and financial viewpoint, since FE models can be made using everyday clinical CT scans without the need of concurrent scanning of calibration phantoms.

Publication
Calibration with or without phantom for fracture risk prediction in cancer patients with femoral bone metastases using CT-based finite element models.
Eggermont F, Verdonschot N, van der Linden Y, Tanck E.

Florieke Eggermont and Esther Tanck are members of theme Reconstructive and regeneratice medicine.

Related news items


Online intervention for women exposed to intimate partner violence

21 November 2019

Within the SAFE project from the department of Primary and Community Care an eHealth intervention has been developed for women exposed to intimate partner violence (IPV).

read more

A personal touch of Sander Leeuwenburgh

21 November 2019

In order to promote interaction amongst colleagues within RIMLS, we have a ‘personal touch’ series setting employees in the spotlight. A light-hearted manner to learn about the colleagues you know and those you don’t. This week: Sander Leeuwenburgh.

read more

Technology for Oncology II grant application funded

21 November 2019

The grant application called "aiREAD – Accurate and Intelligent Reading for EArlier breast cancer Detection” by project leader Ioannis Sechopoulos, has been selected for funding under the NWO TTW – KWF Kankerbestrijding – Top Sector LSH Partnership “Technology for Oncology II”.

read more

KNCV Golden Master Award call for nominations

20 November 2019

The Royal Netherlands Chemistry Society awards this prize each year to the best Master’s research project. The Master’s thesis must relate to research in the field of chemistry, life sciences, process technology or (bio-)molecular sciences. Deadline: 31-12-2019.

read more

Podosome nanoscale architecture redefined

20 November 2019

Koen van den Dries and Alessandra Cambi, theme Nanomedicine, revealed how the nanoscale architecture of podosomes enables dendritic cells to protrude and sense their extracellular environment. They have published their results in Nature Communications.

read more

270 times Homo Universalis in Nijmegen

20 November 2019

What does a scientist of the future look like? International young scientists addressed this important topic during the ENABLE conference, organized by young researchers for young researchers. They showed how the new generation of researchers wants to open up science to the public.

read more