Anders Persson

Linkoping University, Department of Medical and Health Sciences, Faculty Member

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Biography: Anders Persson, M.D., Ph.D. Professor, senior physicianDirector Center for Medical Science and Visualization (CMIV) and professor Department of Medicine and Health, University of Linköping Sweden. 2003. Senior physician Radiology Linköping university Hospital. Guest Professor, Clinical Science Intervention and Technology Karolinska Institute Sweden.Prof. Persson has been working in the field of medical image applications for over 30 years. As a radiologist and researcher, he has worked on the introduction and validation of new visualization tools for the clinical environment and he has taught medical volume rendering in the clinical practice for more than 30 years. Currently his research is focusing on algorithms for specific clinical investigations (Photon counting CT and AI) in cardiovascular image field. He has been a Visiting professor Mayo clinic’s USA, May 2009 – lecturing forensic science. He has >300 Refereed journal and conference publications 2003-2020, >800 Invited talks and 12 book chapters. Several international and national awards such as H.M. The Kings Gold Medal H.M. for special merit in Medical Image Science Research, 2017, RSNA Cum Lade and Lennart Nilsson Award. The Royal Photographic Society Award U.K. 2011, Athena award for best medical research in Sweden. The Royal College Combined Scientific Gold Medal in UK. 2013.

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Papers by Anders Persson

Computed tomography angiography of the coronary arteries with virtual contrast injection

Maximun-likelihood VRT - a new way to visualize MRA datasets

Effect of tube load, model-based iterative reconstruction (MBIR) and slice thickness in abdominal CT using multi-planar reconstruction (MPR)

Poster: "ECR 2019 / C-1185 / Effect of tube load, model-based iterative reconstruction (MBIR... more Poster: "ECR 2019 / C-1185 / Effect of tube load, model-based iterative reconstruction (MBIR) and slice thickness in abdominal CT using multi-planar reconstruction (MPR) " by: " B. Kataria 1, J. Nilsson Althen1, �. Smedby2, A. Persson1, H. Sokjer1, M. Sandborg1; 1Linkoping/SE, 2Huddinge/SE"

Biliary enhancement of Gd-BOPTA and Gd-EOB-DTPA - a study in healthy volunteers

Dual-Energy CT : Uncovering and Troubleshooting New Pitfalls and Artefacts. Educational Exhibit

ABSTRACT PURPOSE/AIM 1. To review pitfalls and limitations in Dual Energy CT (DECT) acquisition a... more ABSTRACT PURPOSE/AIM 1. To review pitfalls and limitations in Dual Energy CT (DECT) acquisition and image reconstruction. 2. To discuss trouble-shooting strategies in view of current and evolving DECT techniques. CONTENT ORGANIZATION 1. Dual Energy CT technique is described, specifically in the context of patient- and technology-related limitations such as artefacts and how these can be addressed. 2. Use of reconstruction parameters in order to support material decomposition is discussed, including different pitfalls in the reconstruction process. 3. New techniques and approaches to handle the specific characteristics of DECT image datasets are discussed. SUMMARY Dual Energy CT involves new factors to be considered when optimizing examination and reconstruction methods and provides a material decomposition capability exceeding that of traditional CT. Knowledge of the characteristics of Dual Energy CT image formation and an understanding of its specific current limitations and pitfalls is essential for optimizing image quality and performing material decomposition, with available and emerging techniques.

Comparison of the Agatston score acquired with photon-counting detector CT and energy-integrating detector CT: Ex vivo study of cadaveric hearts

The purpose of this study was to compare the correlation and agreement between AS derived from ei... more The purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. Method In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50-150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-proces...

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Interactive visualization of 3d scanned mummies at public venues

Communications of the ACM, 2016

A full-body virtual autopsy of an ancient Egyptian mummy showed visitors he was likely murdered.

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Evaluation of transfer function methods in direct volume rendering of the blood vessel lumen

Eurographics, Sep 4, 2014

Visualization of contrast enhanced blood vessels in CT angiography data presents a challenge due ... more Visualization of contrast enhanced blood vessels in CT angiography data presents a challenge due to varying concentration of the contrast agent. The purpose of this work is to evaluate the correctness (effectiveness) in visualizing the vessel lumen using two different 3D visualization strategies, thereby assessing the feasibility of using such visualizations for diagnostic decisions. We compare a standard visualization approach with a recent method which locally adapts to the contrast agent concentration. Both methods are evaluated in a parallel setting where the participant is instructed to produce a complete visualization of the vessel lumen, including both large and small vessels, in cases of calcified vessels in the legs. The resulting visualizations are thereafter compared in a slice viewer to assess the correctness of the visualized lumen. The results indicate that the participants generally overestimated the size of the vessel lumen using the standard visualization, whereas the locally adaptive method better conveyed the true anatomy. The participants did find the interpretation of the locally adaptive method to be less intuitive, but also noted that this did not introduce any prohibitive complexity in the work flow. The observed trends indicate that the visualized lumen strongly depends on the width and placement of the applied transfer function and that this dependency is inherently local rather than global. We conclude that methods that permit local adjustments, such as the method investigated in this study, can be beneficial to certain types of visualizations of large vascular trees.

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Postmortem quantitative 1.5-T MRI for the differentiation and characterization of serous fluids, blood, CSF, and putrefied CSF

International Journal of Legal Medicine, 2015

The purpose of the present study was to investigate whether serous fluids, blood, cerebrospinal f... more The purpose of the present study was to investigate whether serous fluids, blood, cerebrospinal fluid (CSF), and putrefied CSF can be characterized and differentiated in synthetically calculated magnetic resonance (MR) images based on their quantitative T 1 , T 2 , and proton density (PD) values. Images from 55 postmortem short axis cardiac and 31 axial brain 1.5-T MR examinations were quantified using a quantification sequence. Serous fluids, fluid blood, sedimented blood, blood clots, CSF, and putrefied CSF were analyzed for their mean T 1 , T 2 , and PD values. Body core temperature was measured during the MRI scans. The fluid-specific quantitative values were related to the body core temperature. Equations to correct for temperature differences were generated. In a 3D plot as well as in statistical analysis, the quantitative T 1 , T 2 and PD values of serous fluids, fluid blood, sedimented blood, blood clots, CSF, and putrefied CSF could be well differentiated from each other. The quantitative T 1 and T 2 values were temperature-dependent. Correction of quantitative values to a temperature of 37°C resulted in significantly better discrimination between all investigated fluid mediums. We conclude that postmortem 1.5-T MR quantification is feasible to discriminate between blood, serous fluids, CSF, and putrefied CSF. This finding provides a basis for the computeraided diagnosis and detection of fluids and hemorrhages.

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Biliary Enhancement of Gd-BOPTA (MultiHance®) and Gd-EOB-DTPA (Primovist®)-a Study in Healthy Volunteers

N. Dahlström, T. B. Brismar, A. Persson, N. Albiin, Ö. Smedby Center for Medical Image Science an... more N. Dahlström, T. B. Brismar, A. Persson, N. Albiin, Ö. Smedby Center for Medical Image Science and Visualization (CMIV), Linköping University Hospital, Linköping, Sweden, Department of Radiology, Hudiksvall Hospital, Hudiksvall, Sweden, Department of Radiology, Karolinska University Hospital Huddinge, Stockholm, Sweden Introduction: The gallbladder and in particular the bile ducts are readily depicted by heavily T2-weighted MRC(P) acquisitions. Contrast media giving intraluminal enhancement in the biliary system can, in addition to displaying its morphology, also provide functional dynamic information of the hepatobiliary system. There are two contrast agents based on gadolinium which may be used, Gd-BOPTA (Multihance®) and Gd-EOB-DTPA (Primovist®). They differ in hepatocellular enhancement properties as well as in the degree of biliary elimination (5% for Gd-BOPTA and 50% for GdEOB-DTPA). This study aimed to investigate the dynamics of bile duct enhancement relative to that of liver parenchyma for both these contrast agents.

The aim of this study was to compare the enhancement dynamics in the liver of Gd-BOPTA (MultiHance®) and Gd-EOB-DTPA (Primovist®). The conventional MRI contrast agents based on Gd-DTPA display the vascularity of organs and lesions. When imaging liver lesions an added liver specific enhancement an...

Multilayer Quick Time Virtual Reality Object Movie: A New Way to Share High Dimensional Post-processing Results

Three-dimensional drip infusion CT cholangiography in patients with suspected obstructive biliary disease: A retrospective analysis of feasibility and adverse reaction to contrast material

BMC Medical Imaging, 2006

Background: Computed Tomography Cholangiography (CTC) is a fast and widely available alternative ... more Background: Computed Tomography Cholangiography (CTC) is a fast and widely available alternative technique to visualise hepatobiliary disease in patients with an inconclusive ultrasound when MRI cannot be performed. The method has previously been relatively unknown and sparsely used, due to concerns about adverse reactions and about image quality in patients with impaired hepatic function and thus reduced contrast excretion. In this retrospective study, the feasibility and the frequency of adverse reactions of CTC when using a drip infusion scheme based on bilirubin levels were evaluated. Methods: The medical records of patients who had undergone upper abdominal spiral CT with subsequent three-dimensional rendering of the biliary tract by means of CTC during seven years were retrospectively reviewed regarding serum bilirubin concentration, adverse reaction and presence of visible contrast media in the bile ducts at CT examination. In total, 153 consecutive examinations in 142 patients were reviewed. Results: Contrast media was observed in the bile ducts at 144 examinations. In 110 examinations, the infusion time had been recorded in the medical records. Among these, 42 examinations had an elevated bilirubin value (>19 umol/L). There were nine patients without contrast excretion; 3 of which had a normal bilirubin value and 6 had an elevated value (25-133 umol/L). Two of the 153 examinations were inconclusive. One subject (0.7%) experienced a minor adverse reaction-a pricking sensation in the face. No other adverse effects were noted. Conclusion: We conclude that drip infusion CTC with an infusion rate of the biliary contrast agent iotroxate governed by the serum bilirubin value is a feasible and safe alternative to MRC in patients with and without impaired biliary excretion. In this retrospective study the feasibility and the frequency of adverse reactions when using a drip infusion scheme based on bilirubin levels has been evaluated.

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Volume rendering of three-dimensional drip infusion CT cholangiography in patients with suspected obstructive biliary disease: a retrospective study

The British Journal of Radiology, 2005

Standardized Volume Rendering for Magnetic Resonance Angiography Measurements in the Abdominal Aorta

Acta Radiologica, 2006

To compare three methods for standardizing volume rendering technique (VRT) protocols by studying... more To compare three methods for standardizing volume rendering technique (VRT) protocols by studying aortic diameter measurements in magnetic resonance angiography (MRA) datasets. Datasets from 20 patients previously examined with gadolinium-enhanced MRA and with digital subtraction angiography (DSA) for abdominal aortic aneurysm were retrospectively evaluated by three independent readers. The MRA datasets were viewed using VRT with three different standardized transfer functions: the percentile method (Pc-VRT), the maximum-likelihood method (ML-VRT), and the partial range histogram method (PRH-VRT). The aortic diameters obtained with these three methods were compared with freely chosen VRT parameters (F-VRT) and with maximum intensity projection (MIP) concerning inter-reader variability and agreement with the reference method DSA. F-VRT parameters and PRH-VRT gave significantly higher diameter values than DSA, whereas Pc-VRT gave significantly lower values than DSA. The highest interobserver variability was found for F-VRT parameters and MIP, and the lowest for Pc-VRT and PRH-VRT. All standardized VRT methods were significantly superior to both MIP and F-VRT in this respect. The agreement with DSA was best for PRH-VRT, which was the only method with a mean error below 1 mm and which also had the narrowest limits of agreement (95% of cases between 2.1 mm below and 3.1 mm above DSA). All the standardized VRT methods compare favorably with MIP and VRT with freely selected parameters as regards interobserver variability. The partial range histogram method, although systematically overestimating vessel diameters, gives results closest to those of DSA.

Volume rendering compared with maximum intensity projection for magnetic resonance angiography measurements of the abdominal aorta

Acta Radiologica, 2004

Purpose: To compare the volume rendering technique (VRT) with maximum intensity projection (MIP) ... more Purpose: To compare the volume rendering technique (VRT) with maximum intensity projection (MIP) for aortic diameter measurements in MR angiography (MRA) data sets. Material and Methods: Existing contrast‐enhanced 3‐dimensional MRA and digital subtraction angiography (DSA) data sets from 20 patients were analyzed. In each MRA data set, two aortic diameters were measured using MIP and VRT. Agreement with DSA measurements, dependence on rendering parameters, and interobserver agreement were assessed. Results: Diameters measured on MIP with fixed parameters showed no significant difference compared with DSA and with freely selected parameters a slight overestimation relative to DSA. Diameters measured on VRT were larger than on DSA. For both MIP and VRT, the measurements depended on the chosen parameters. The error relative to DSA was larger for VRT than for MIP with fixed parameters but not with freely chosen parameters. Interobserver agreement did not differ significantly. Conclusion...

Computed tomographic colonography: comparison of two workstations

Acta Radiologica, 2005

Purpose: To compare two commercially available computed tomography (CT) colonography systems with... more Purpose: To compare two commercially available computed tomography (CT) colonography systems with respect to interobserver variability, the influence of level of expertise, and the gradual reduction of reviewing time for each system.Material and Methods: Two residents and two radiologists using Siemens CTAPP Colography software and Viatronix V3D-Colon software reviewed supine and prone CT acquisitions from 24 patients in a primary 3D endoluminal view. The observers graded each case with respect to technical quality and diagnostic value, assessed the presence of pathology, and indicated the time spent on the viewing.Results: Significant differences were found in technical quality ( P<0.001) and diagnostic value ( P<0.001) depending on which system was used, with higher scores for the Viatronix software. The agreement between specialists tended to be higher than that between residents (κ = 0.63 (0.30–0.95) vs. κ = 0.51 (0.21–0.81)), and the residents gave significantly ( P<0....

Measurements Before Endovascular Repair Of Abdominal Aortic Aneurysms. MR imaging with MRA vs. angiography and CT

Acta Radiologica, 2003

Purpose: 1) To compare measurements obtained with MR imaging (MRI)/ contrast-enhanced MR angiogra... more Purpose: 1) To compare measurements obtained with MR imaging (MRI)/ contrast-enhanced MR angiography (CE MRA) with measurements obtained with angiography (DSA) and CT, for stent-graft sizing of abdominal aortic aneurysms (AAA). 2) To compare MRA measurements obtained with the two post processing techniques MIP (maximum intensity projection) and VRT (3D volume rendering technique). Material and Methods: The prospective study included 20 consecutive patients with AAA identified by DSA and CT as suitable for endovascular repair. For the study, MRI/CE MRA was performed. Five measurement variables for stentgraft sizing were chosen. Comparisons were made between MRI/CE MRA, DSA and CT, and between observers. Comparisons were also made between MIP and VRT. Results: Significantly shorter lengths were obtained with MRA-MIP than with DSA. Three out of six diameter measurements were significantly smaller on MRI/CE MRA than on DSA and CT. No significant differences were found between the observers. One diameter measurement was significantly smaller on MIP than on VRT, while the other measurements showed no significant differences. Conclusion: The length measurements obtained with MRA-MIP were probably more correct than those with DSA. For more reliable diameter measurements with CE MRA, improvements of the technique, including VRT reconstructions and a standardized determination of the vessel boundaries, are needed.

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Can segmented 3D images be used for stenosis evaluation in coronary CT angiography?

Acta Radiologica, 2012

Background Thanks to the development of computed tomography (CT) scanners and computer software, ... more Background Thanks to the development of computed tomography (CT) scanners and computer software, accurate coronary artery segmentation can be achieved with minimum user interaction. However, the question remains whether we can use these segmented images for reliable diagnosis. Purpose To retrospectively evaluate the diagnostic accuracy of coronary CT angiography (CCTA) using segmented 3D data for the detection of significant stenosis. Material and Methods CCTA data-sets from 30 patients were acquired with a 64-slice CT scanner and segmented using the region growing (RG) method and the “virtual contrast injection” (VC) method. Three types of images of each patient were reviewed by different reviewers for the presence of stenosis with diameter reduction of 50% or more. The evaluation was performed on four main arteries of each patient (120 arteries in total). For the original series, the reviewer was allowed to use all the 2D and 3D visualization tools available (conventional method)....

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The aim of this study was to compare the enhancement dynamics in the liver of Gd-BOPTA (MultiHancetextregistered) and Gd-EOB-DTPA (Primovisttextregistered). The conventional MRI contrast agents based on Gd-DTPA display the vascularity of organs and lesions. When imaging liver lesions an added liv...