Diagnostic performance of low field MRI in acute knee injuries

1994 ◽  
Vol 12 (8) ◽  
pp. 1155-1160 ◽  
Author(s):  
Jaakko Kinnunen ◽  
Sören Bondestam ◽  
Aarne Kivioja ◽  
Juhani Ahovuo ◽  
Sanna-Kaisa Toivakka ◽  
...  
2013 ◽  
Vol 20 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Jaakko O. Nieminen ◽  
Jens Voigt ◽  
Stefan Hartwig ◽  
Hans Jürgen Scheer ◽  
Martin Burghoff ◽  
...  

Abstract The spin-lattice (T1) relaxation rates of materials depend on the strength of the external magnetic field in which the relaxation occurs. This T1 dispersion has been suggested to offer a means to discriminate between healthy and cancerous tissue by performing magnetic resonance imaging (MRI) at low magnetic fields. In prepolarized ultra-low-field (ULF) MRI, spin precession is detected in fields of the order of 10-100 μT. To increase the signal strength, the sample is first magnetized with a relatively strong polarizing field. Typically, the polarizing field is kept constant during the polarization period. However, in ULF MRI, the polarizing-field strength can be easily varied to produce a desired time course. This paper describes how a novel variation of the polarizing-field strength and duration can optimize the contrast between two types of tissue having different T1 relaxation dispersions. In addition, NMR experiments showing that the principle works in practice are presented. The described procedure may become a key component for a promising new approach of MRI at ultra-low fields


2020 ◽  
Vol 6 (1) ◽  
pp. e000950
Author(s):  
Sanne Fomin ◽  
Håkan Gauffin ◽  
Joanna Kvist

ObjectivesTo describe self-reported knee function, participation in physical activity and the number of knee surgeries at 3 and 6 months following acute knee injury.MethodsProspective cohort study. Participants, aged 15–40 years with an acute knee injury sustained no more than 6 weeks prior to inclusion, were recruited. There were 279 participants with ACL injury and 101 participants with other acute knee injuries included. Follow-up questionnaires were sent at 3 and 6 months after injury. Demographic information, activity participation, International Knee Documentation Committee subjective knee form (IKDC-SKF) and the Single Assessment Numeric Evaluation (SANE) score were collected. Additional knee injuries were obtained from self-report and medical charts.ResultsThe IKDC-SKF, SANE and physical activity participation were reduced at 3-month and 6-month follow-up. The number of participants who achieved health-promoting physical activity levels was reduced by 50% at 6-month follow-up compared with before injury. Seventeen per cent of participants with ACL injury and 41% of participants with other acute knee injuries had returned to their preinjury physical activity at 6 months. Participants with ACL injury reported worse knee function, lower physical activity participation and had more surgeries (128 surgeries, including 109 ACL-reconstructions) compared with participants with other acute knee injuries (six surgeries).ConclusionAcute knee injuries, including ACL injuries, affected self-reported knee function and physical activity participation for at least 6 months after index injury. More research is needed to understand how best to help people with acute knee injuries return to physical activity and achieve satisfactory knee function.


2021 ◽  
Author(s):  
Armando Garcia Hernandez ◽  
Pierre Fau ◽  
Stanislas Rapacchi ◽  
Julien Wojak ◽  
Hugues Mailleux ◽  
...  

1993 ◽  
Vol 93 (3) ◽  
pp. 75-86 ◽  
Author(s):  
Mitchell H. Rothenberg ◽  
Ben K. Graf
Keyword(s):  

2002 ◽  
Vol 171 (S2) ◽  
pp. 71-72
Author(s):  
S. R. Kearns ◽  
S. H. Orakzai ◽  
H. A. Ridha ◽  
G. Roche-Nagle ◽  
P. Keogh ◽  
...  

1994 ◽  
Vol 12 (3) ◽  
pp. 395-401 ◽  
Author(s):  
Kirsti I. Dean ◽  
Markku Komu

2021 ◽  
Author(s):  
Dang Bich Thuy Le ◽  
Meredith Sadinski ◽  
Aleksandar Nacev ◽  
Ram Narayanan ◽  
Dinesh Kumar

2004 ◽  
Vol 22B (1) ◽  
pp. 1-6 ◽  
Author(s):  
Giulio Giovannetti ◽  
Raffaello Francesconi ◽  
Luigi Landini ◽  
Vittorio Viti ◽  
Maria Filomena Santarelli ◽  
...  

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