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Wang X, Uhlemann F, Borgert J, Chaduvula SC, Tellis R, Frydrychowicz A, Barkhausen J, Amthor T. Analysis and predictability of technologists' perception of MR exam complexity. Radiography (Lond) 2024; 30:151-158. [PMID: 38035426 DOI: 10.1016/j.radi.2023.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/20/2023] [Accepted: 10/19/2023] [Indexed: 12/02/2023]
Abstract
INTRODUCTION As MRI becomes a routine clinical diagnostic method, its complexity of techniques, protocols and scanning is growing. On the other hand, aggravated by the ubiquitous shortage of workforce, technologists' stress level and burnout rates are increasing. In this context, our study aims to shed light on technologists' perceived complexity of MR exams, by analyzing a multidimensional dataset composed of workflow, patient, and operational details, and further predicting perceived exam complexity. METHODS In this IRB-approved study, data about imaging workflow, exam context, and patient characteristics were collected over one year from MR modality logfiles and from technologist questionnaires, including the perceived exam complexity. The association of individual factors with complexity was analyzed via Fisher's exact tests and Cramér's V values. Predictability of exam complexity was further evaluated via ROC analysis of three different multivariate classifiers. RESULTS Retakes, delays, and extended exam duration are associated with perceived complexity (V ≥ 0.2). From the set of possible predictors, patient mobility and communication ability have the most influence on perceived complexity (V > 0.2), followed by special equipment needs (pulse oximetry, intubation, or ECG), protocol details and other patient characteristics. Feasibility of predicting the perceived exam complexity from a multivariate set of exam and patient details known at the time of scheduling has been demonstrated (AUC = 0.73), and suitable classification algorithms have been identified. CONCLUSION Perceived exam complexity is associated with various factors. Our results suggest that it can be predicted sufficiently well to support early operational decision making. Some factors, however, may not be readily available in hospital IT systems and must be obtained before scheduling. IMPLICATIONS FOR PRACTICE Results and observations of this study could be utilized to assist operational scheduling in the radiology department and reduce MR technologists' stress levels.
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Affiliation(s)
- X Wang
- Philips Research Europe, Hamburg, Germany.
| | - F Uhlemann
- Philips Research Europe, Hamburg, Germany
| | - J Borgert
- Philips Research Europe, Hamburg, Germany
| | | | - R Tellis
- Philips Research North America, Cambridge, MA, USA
| | | | - J Barkhausen
- University Hospital Schleswig-Holstein, Lübeck, Germany
| | - T Amthor
- Philips Research Europe, Hamburg, Germany
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Hägele J, Vaalma S, Panagiotopoulos N, Barkhausen J, Vogt F, Borgert J, Rahmer J. Farbkodiertes Magnetic Particle Imaging für kardiovaskuläre Interventionen. ROFO-FORTSCHR RONTG 2016. [DOI: 10.1055/s-0036-1581198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hägele J, Panagiotopoulos N, Cremers S, Rahmer J, Franke J, Duschka R, Vaalma S, Heidenreich M, Borgert J, Borm P, Barkhausen J, Vogt F. SPION-Beschichtung von Instrumenten für MPI-gesteuerte kardiovaskuläre Interventionen. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1550865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Borgert J. Einführung in Magnetic Particle Imaging (MPI). ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1550813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Rahmer J, Halkola A, Gleich B, Schmale I, Borgert J. First experimental evidence of the feasibility of multi-color magnetic particle imaging. Phys Med Biol 2015; 60:1775-91. [PMID: 25658130 DOI: 10.1088/0031-9155/60/5/1775] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Magnetic particle imaging is a new approach to visualizing magnetic nanoparticles. It is capable of 3D real-time in vivo imaging of particles injected into the blood stream and is a candidate for medical imaging applications. To date, only one particle type has been imaged at a time, however, the ability to separate signals acquired simultaneously from different particle types or from particles in different environments would substantially increase the scope of the method. Different colors could be assigned to different signal sources to allow for visualization in a single image. Successful signal separation has been reported in spectroscopic experiments, but it was unclear how well separation would work in conjunction with spatial encoding in an imaging experiment. This work presents experimental evidence of the separability of signals from different particle types and aggregation states (fluid versus powder) using a 'multi-color' reconstruction approach. Several mechanisms are discussed that may form the basis for successful signal separation.
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Affiliation(s)
- J Rahmer
- Philips GmbH Innovative Technologies, Research Laboratories, Röntgenstraße 24-26, D-22315 Hamburg, Germany
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Rahmer J, Antonelli A, Sfara C, Tiemann B, Gleich B, Magnani M, Weizenecker J, Borgert J. Nanoparticle encapsulation in red blood cells enables blood-pool magnetic particle imaging hours after injection. Phys Med Biol 2013; 58:3965-77. [PMID: 23685712 DOI: 10.1088/0031-9155/58/12/3965] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases.
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Affiliation(s)
- J Rahmer
- Philips Technologie GmbH Innovative Technologies, Research Laboratories, Röntgenstrasse 24-26, D-22315 Hamburg, Germany.
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Duschka RL, Wojtczyk H, Panagiotopoulos N, Haegele J, Bringout G, Rahmer J, Bontus C, Buzug TM, Borgert J, Barkhausen J, Vogt FM. Magnetic Particle Imaging (MPI): Sicherheitsmessungen gängiger, interventionell verwendeter Materialien mit gezieltem Focus auf die Materialerwärmung. ROFO-FORTSCHR RONTG 2013. [DOI: 10.1055/s-0033-1346219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Duschka RL, Wojtczyk H, Panagiotopoulos N, Hägele J, Bringout G, Rahmer J, Bontus C, Buzug TM, Borgert J, Barkhausen J, Vogt FM. Magnetic Particle Imaging (MPI) meets Katheter und Co. – Temperaturmessungen interventioneller Materialen im Wechselmagnetfeld. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1329771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gräfe K, Sattel TF, Lüdtke-Buzug K, Finas D, Borgert J, Buzug TM. An Application Scenario for Single-Sided Magnetic Particle Imaging. ACTA ACUST UNITED AC 2012. [DOI: 10.1515/bmt-2012-4343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- K. Gräfe
- Institute of Medical Engineering, University of Luebeck, Lübeck, Germany
| | - T. F. Sattel
- Institute of Medical Engineering, University of Luebeck, Lübeck, Germany
| | - K. Lüdtke-Buzug
- Institute of Medical Engineering, University of Luebeck, Lübeck, Germany
| | - D. Finas
- Department of Obstetrics and Gynaecology, University of Luebeck, Lübeck, Germany
| | - J. Borgert
- Phillips Technology GmbH, Innovative Technologies, Research Laboratories, Hamburg, Germany
| | - T. M. Buzug
- Institute of Medical Engineering, University of Luebeck, Lübeck, Germany
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Hägele J, Rahmer J, Gleich B, Bontus C, Borgert J, Wojtczyk H, Buzug TM, Barkhausen J, Vogt FM. Darstellung von Instrumenten zur Magnetic Particle Imaging (MPI) gesteuerten kardiovaskulären Intervention. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1311012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Abstract
Magnetic particle imaging (MPI) is a new tomographic imaging method which is able to capture the fast dynamic behavior of magnetic tracer material. From measured induced signals, the unknown magnetic particle concentration is reconstructed using a previously determined system function, which describes the relation between particle position and signal response. After discretization, the system function is represented by a matrix, whose size can prohibit the use of direct solvers for matrix inversion to reconstruct the image. In this paper, we present a new reconstruction approach, which combines efficient compression techniques and iterative reconstruction solvers. The data compression is based on orthogonal transforms, which extract the most relevant information from the system function matrix by thresholding, such that any iterative solver is strongly accelerated. The effect of the compression with respect to memory requirements, computational complexity and image quality is investigated. With the proposed method, it is possible to achieve real-time reconstruction with almost no loss in image quality using measured 4D MPI data.
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Affiliation(s)
- J Lampe
- Institute of Numerical Simulation, Hamburg University of Technology, D-21071 Hamburg, Germany.
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Haegele J, Rahmer J, Gleich B, Bontus C, Borgert J, Wojtczyk H, Buzug TM, Barkhausen J, Vogt FM. Darstellung von Instrumenten zur Magnetic Particle Imaging (MPI) gesteuerten kardiovaskulären Intervention. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0031-1300903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Haegele J, Sattel T, Erbe M, Luedtke-Buzug K, Taupitz M, Borgert J, Buzug TM, Barkhausen J, Vogt FM. [Magnetic particle imaging (MPI)]. ROFO-FORTSCHR RONTG 2011; 184:420-6. [PMID: 22198836 DOI: 10.1055/s-0031-1281981] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Magnetic particle imaging (MPI) displays the spatial distribution and concentration of superparamagnetic iron oxides (SPIOs). It is a quantitative, tomographic imaging method with high temporal and spatial resolution and allows work with high sensitivity yet without ionizing radiation. Thus, it may be a very promising tool for medical imaging. In this review, we describe the physical and technical basics and various concepts for clinical scanners. Furthermore, clinical applications such as cardiovascular imaging, interventional procedures, imaging and therapy of malignancies as well as molecular imaging are presented.
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Affiliation(s)
- J Haegele
- Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Schleswig-Holstein, Lübeck.
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Buzug TM, Sattel TF, Erbe M, Biederer S, Borgert J, Finas D, Dietrich K, Vogt F, Barkhausen J, Lüdtke-Buzug K, Knopp T. Alternative Spulentopologien für Magnetic-Particle-Imaging. ROFO-FORTSCHR RONTG 2010. [DOI: 10.1055/s-0030-1268341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Markov DE, Boeve H, Gleich B, Borgert J, Antonelli A, Sfara C, Magnani M. Human erythrocytes as nanoparticle carriers for magnetic particle imaging. Phys Med Biol 2010; 55:6461-73. [DOI: 10.1088/0031-9155/55/21/008] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Knopp T, Rahmer J, Sattel TF, Biederer S, Weizenecker J, Gleich B, Borgert J, Buzug TM. Weighted iterative reconstruction for magnetic particle imaging. Phys Med Biol 2010. [DOI: 10.1088/0031-9155/55/8/c01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Knopp T, Rahmer J, Sattel TF, Biederer S, Weizenecker J, Gleich B, Borgert J, Buzug TM. Weighted iterative reconstruction for magnetic particle imaging. Phys Med Biol 2010; 55:1577-89. [PMID: 20164532 DOI: 10.1088/0031-9155/55/6/003] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Magnetic particle imaging (MPI) is a new imaging technique capable of imaging the distribution of superparamagnetic particles at high spatial and temporal resolution. For the reconstruction of the particle distribution, a system of linear equations has to be solved. The mathematical solution to this linear system can be obtained using a least-squares approach. In this paper, it is shown that the quality of the least-squares solution can be improved by incorporating a weighting matrix using the reciprocal of the matrix-row energy as weights. A further benefit of this weighting is that iterative algorithms, such as the conjugate gradient method, converge rapidly yielding the same image quality as obtained by singular value decomposition in only a few iterations. Thus, the weighting strategy in combination with the conjugate gradient method improves the image quality and substantially shortens the reconstruction time. The performance of weighting strategy and reconstruction algorithms is assessed with experimental data of a 2D MPI scanner.
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Affiliation(s)
- T Knopp
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany.
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Knopp T, Biederer S, Sattel T, Weizenecker J, Gleich B, Borgert J, Buzug TM. Trajectory analysis for magnetic particle imaging. Phys Med Biol 2008; 54:385-97. [DOI: 10.1088/0031-9155/54/2/014] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Begemann P, Van SU, Timinger H, Grewer R, Borgert J, Nolte-Ernsting C, Grass M, Adam G. Messung der räumlichen und zeitlichen Auflösung bei EKG-korrelierter 16-Zeilen-CT (MSCT) am bewegten Herzphantom. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-827787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Auricht E, Borgert J, Butler M, Cadwallader H, Collignon P, Cooper C, Eades M, Ferguson J, Kampen R, Looke D, McLaws ML, Olesen D, Pawsey M, Richards M, Riley T, Saul J, Spearing N, Thomson R, West R, Whitby M, Wishart M, Zerner L. Uniform national denominator definitions for infection control clinical indicators: surgical site and health care associated blood stream infection. ACTA ACUST UNITED AC 2001. [DOI: 10.1071/hi01047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Auricht E, Borgert J, Butler M, Cadwallader H, Collignon P, Eades M, Ferguson J, Kampen R, Looke D, MacBeth D, McLaws ML, Olesen D, Pawsey M, Richards M, Riley T, Sykes P, Whitby M, West R, Zerner L. Introduction to Australian surveillance definitions: surgical site infection & bloodstream infections. ACTA ACUST UNITED AC 2000. [DOI: 10.1071/hi00325] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Auricht E, Borgert J, Butler M, Cadwallader H, Collignon P, Eades M, Ferguson J, Kampen R, Looke D, Macbeth D, McLaws ML, Olesen D, Pawsey M, Richards M, Riley T, Sykes P, Whitby M. Uniform national numerator definitions for infection control clinical indicators: surgical site infection and health-care related bloodstream infection. ACTA ACUST UNITED AC 1999. [DOI: 10.1071/hi99412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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