List mode file patient 2 (broken neck bimodular endoprosthesis)

TissueMaps is a Marie Curie Project where experts from various backgrounds (Medicine, Physics, Chemistry …) work together to develop more complete diagnostic techniques to improve life of patients using or in need of endoprostheses.

Due to corrosion and/or friction, endoprostheses may generate debris, which can cause toxicity, inflammation and prosthesis unsealing by osseous dissolution. We need to understand the mechanism of dispersion of the different metal particles from the endoprosthesis into the tissue, by the study of the content, size and nature of debris.

During TissueMaps project we collect and analyse human serum and tissue samples. The purpose of the sample collection and data generation is to study into detail the problem of failure endoprosthesis, by the analysis of the metal content in serum and tissue. Sample collection, for both the serum and tissue, is carried out at the Department of Orthopedics UKC Maribor in accordance with the principles of medical ethics and in the interest of patients. All the information regarding the medical history of patients is safety kept at the Hospital files. All the samples and files are named according to a code to avoid the identification of the patient.

At Department of Low and Medium Energy Physics F2 (MIC) at the Jožef Stefan Institute (JSI) we are carrying out the study of the metallic particles dispersed into the human tissue after the endoprosthesis failure. We use a technique called Particle Induced X-ray Emission, to determine the distribution and quantification of metallic particles, with a lateral resolution under the micro-regime, the so-called micro-PIXE technique (https://tissuemaps.wordpress.com/2019/05/16/physics-behind/).

We are sharing the lmf (list mode files) from the PIXE measurements from the elemental maps already published in scientific articles, Conference posters and oral presentations. We will also share the lmf from other representative unpublished cases.

The list mode files are the most completed files we can share. Each file contains:

X-rays recorded at the two X-ray detectors, Silicon Drift Detector (SDD) and intrinsic Germanium detectors (iGe). The SDD detector is used for the detection of lighter elements, while the iGe detector, with a better energy resolution, it is used for the detection of heavier elements.

Spectrum from backscattered protons from the sample, that can be used for quantification, and from backscattered protons coming from chopper, that is used for dose quantification.

The information regarding the areal density of the samples can be extracted from the scanning transmission ion microscopy. This information can be used to complete the quantification information.

--> In this file (973003.lmf) we are sharing the "list mode file" from our so-called "patient 2". This pacient suffered from a broken endoprosthesis. A Profemur Z model. A prosthesis replacement was needed. During the replacement surgery the tissue sample was taken and processed to by analyzed. Lots of metallic debris can be found into the soft periprosthetic tissue. 
More detailed information can be found at the following open access journal publication: "Particle Induced X-ray Emission (PIXE) for elemental tissue imaging in hip modular prosthesis fracture case".
Open access: https://www.sciencedirect.com/science/article/pii/S0168583X19306846

GeoPIXE software to transform the list mode files into elemental maps

As we exposed before, the list mode files are the most completed data we are able to share. Each file contains the most complete information of the scanned area.

There are various softwares available that can be used to obtain the elemental map distribution from the list mode files. We have used the software GeoPIXETM. The software is not free. To get access to the software you can contact the company CSIRO Earth Science and Resource Engineering (Austrialia) thought its web page:

http://nmp.csiro.au/GeoPIXE.html