This "readme - Stähli et al 2020 Ultrasonics.txt" file was generated on 2024-04-02 by 
Michael Jaeger, Institute of Applied Physics, University of Bern 

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GENERAL INFORMATION
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1. Title of dataset: "Raw data used in Stähli et al. 2020 Ultrasonics 108" 

2. Short description: 
Echo ultrasound raw data used in "the paper": 
"Improved forward model for quantitative pulse-echo speed-of-sound
imaging" Stähli et al. 2020, Ultrasonics 108, 106168-1--17, doi: 10.1016/j.ultras.2020.106168 

3. Contributor information: 
Patrick Stähli, first author and data creator: code development, phantom building, data acquisition, data analysis, manuscript writing. 
Maju Kuriakose: scientific discussions 
Martin Frenz, principal investigator: manuscript editing   
Michael Jaeger, group leader: scientific supervision, manuscript editing, data curation 
 
For questions, contact: 
Michael Jaeger, group leader 
Institute of Applied Physics, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland 
michael.jaeger@unibe.ch 

4. Date of data collection: 
2018-04-10 to 2019-10-29 

5. Geographic location of data collection:  
Bern, Switzerland 

6. Keywords:  
Ultrasound tomography, reflection mode, multimodal imaging, inverse problem

7. Information about funding sources that supported the collection of the data:  
Funding agency: Swiss National Science Foundation 
Grant number: 205320_178038 
Funding agency: European Union’s Horizon 2020 research and innovation
programme 
Grant number: 732411 
Funding agency: Photonics Private Public Partnership 
Funding agency: Swiss State Secretariat for Education,
Research and Innovation (SERI) 
Grant number: 
16.0162 

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SHARING/ACCESS INFORMATION 
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1. Licenses/restrictions placed on the data: 
Attribution NonCommercial-NoDerivs CC BY-NC-SA

2. Links to publications that cite or use the data: 
DOI 10.1016/j.ultras.2020.106168 
https://www.sciencedirect.com/science/article/pii/S0041624X20301074

3. Was data derived from another source? No 

4. Recommended citation for this dataset: 
Patrick Stähli, Maju Kuriakose, Martin Frenz, Michael Jaeger "Raw data used in Stähli et al. 2020 Ultrasonics 108" 2024, BORIS, https://doi.org/10.48620/387

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DATA & FILE OVERVIEW  
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1. File list: 
The files are named according to the nomenclatura in the paper. In addition, there are 3 files containing data for system calibration. Calibration was used for the results shown in the figures, even though it was not mentionned in the paper. The calibration procedure is, however, described in Jaeger et al. "Pulse-echo speed-of-sound imaging using convex probes" 2022 Phys Med Biol 67, 215016-1--17, doi: 10.1088/1361-6560/ac96c6

Fig. 8: 
2-layer.pw.mat 

Fig. 9: 
4-layer.pw.mat

Fig. 10: 
LVMD.pw.mat

Fig. 11: 
1-layer-inclusion.pw.mat 

Fig. 12: 
2-layer-inclusion.pw.mat 

Fig. 14: 
liver_1 to liver_5.pw.mat 

Calibration: 
calibration_1.pw.mat 
calibration_2.pw.mat
calibration_3.pw.mat
calibration_4.pw.mat

2. Relationship between files: 
none 

3. Are there multiple versions of the dataset? no 

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METHODOLOGICAL INFORMATION  
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1. Description of methods used for collection/generation of data: 
The data were acquired using a L7-4 linear vascular probe (ATL Philips, WA, USA), 
connected to a Vantage 64 LE (Verasonics Inc., WA, USA) research ultrasound system. 

For details see: 
"Improved forward model for quantitative pulse-echo speed-of-sound
imaging" Stähli et al. 2020, Ultrasonics 108, 106168-1--17, doi: 10.1016/j.ultras.2020.106168 

2. Methods for processing the data 
For ease of use, the raw data from the Verasonics system was converted to a self-explaining format. 
Each .mat file contains two variables: 
"metadata" a structure with fields describing important parameters for the interpreation of the data 
"rawdata" a matrix containing the signal values, where dimensions correspond to (time, element index, acquisition angle) 

3. Instrument- or software-specific information needed to interpret the data: 
Information needed for interpretation are found in the "metadata" variable 

4. Standards and calibration information: 
No standards or calibration were used for producing the data. When processing the data, however, note that calibration data is available (see above) for calibrating the desired results. 

5. Quality-assurance procedures: 
None 

6. People involved with sample collection, processing, analysis, curation: 
Patrick Stähli, Michael Jaeger 

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DATA-SPECIFIC INFORMATION  
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Data were acquired from phantoms made of gelatine, cellulose, oil in gelatine. For further detail read the article. The reference SoS values were: 

Two-layer phantom: (from top to bottom) 1420 m/s, 1555 m/s 
Four-layer phantom: (from top to bottom) 1420 m/s, 1555 m/s, 1420 m/s, 1555 m/s 
LVMD phantom: (from top to bottom) 1420 m/s, 1555 m/s, 1420 m/s, 1555 m/s 
One-layer inclusion phantom: cylinder with 1570 m/s inside background of 1540 m/s 
Two-layer inclusion phantom: cylinder with 1570 m/s inside layer with 1540 m/s, with additional 
layer with 1570 m/s below. 

Abdominal data were acquired from a healthy volunteer with the imaging plane perpendicular to the linea alba on top of the liver. Five acquisitions were taken, so that the resulting SoS maps can 
be averaged to reduce noise. 

"calibration ...pw.mat" were acquired from a phantom made of agar and cellulose, in slightly different positions with decorrelated speckle. The reference SoS value is 1490 m/s