@article{HertleinSturmKircheretal.2011, author = {Hertlein, Tobias and Sturm, Volker and Kircher, Stefan and Basse-L{\"u}sebrink, Thomas and Haddad, Daniel and Ohlsen, Knut and Jakob, Peter}, title = {Visualization of Abscess Formation in a Murine Thigh Infection Model of \(Staphylococcus\) \(aureus\) by (19)F-Magnetic Resonance Imaging (MRI)}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0018246}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142846}, pages = {e18246}, year = {2011}, abstract = {Background: During the last years, (19)F-MRI and perfluorocarbon nanoemulsion (PFC) emerged as a powerful contrast agent methodology to track cells and to visualize inflammation. We applied this new modality to visualize deep tissue abscesses during acute and chronic phase of inflammation caused by Staphylococcus aureus infection. Methodology and Principal Findings: In this study, a murine thigh infection model was used to induce abscess formation and PFC or CLIO (cross linked ironoxides) was administered during acute or chronic phase of inflammation. 24 h after inoculation, the contrast agent accumulation was imaged at the site of infection by MRI. Measurements revealed a strong accumulation of PFC at the abscess rim at acute and chronic phase of infection. The pattern was similar to CLIO accumulation at chronic phase and formed a hollow sphere around the edema area. Histology revealed strong influx of neutrophils at the site of infection and to a smaller extend macrophages during acute phase and strong influx of macrophages at chronic phase of inflammation. Conclusion and Significance: We introduce (19)F-MRI in combination with PFC nanoemulsions as a new platform to visualize abscess formation in a murine thigh infection model of S. aureus. The possibility to track immune cells in vivo by this modality offers new opportunities to investigate host immune response, the efficacy of antibacterial therapies and the influence of virulence factors for pathogenesis.}, language = {en} } @article{JakobHertleinSturmetal.2011, author = {Jakob, Peter and Hertlein, Tobias and Sturm, Volker and Kircher, Stefan and Basse-L{\"u}sebrink, Thomas and Haddad, Daniel and Ohlsen, Knut}, title = {Visualization of Abscess Formation in a Murine Thigh Infection Model of Staphylococcus aureus by 19F-Magnetic Resonance Imaging (MRI)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74994}, year = {2011}, abstract = {Background: During the last years, 19F-MRI and perfluorocarbon nanoemulsion (PFC) emerged as a powerful contrast agent based MRI methodology to track cells and to visualize inflammation. We applied this new modality to visualize deep tissue abscesses during acute and chronic phase of inflammation caused by Staphylococcus aureus infection. Methodology and Principal Findings: In this study, a murine thigh infection model was used to induce abscess formation and PFC or CLIO (cross linked ironoxides) was administered during acute or chronic phase of inflammation. 24 h after inoculation, the contrast agent accumulation was imaged at the site of infection by MRI. Measurements revealed a strong accumulation of PFC at the abscess rim at acute and chronic phase of infection. The pattern was similar to CLIO accumulation at chronic phase and formed a hollow sphere around the edema area. Histology revealed strong influx of neutrophils at the site of infection and to a smaller extend macrophages during acute phase and strong influx of macrophages at chronic phase of inflammation. Conclusion and Significance: We introduce 19F-MRI in combination with PFC nanoemulsions as a new platform to visualize abscess formation in a murine thigh infection model of S. aureus. The possibility to track immune cells in vivo by this modality offers new opportunities to investigate host immune response, the efficacy of antibacterial therapies and the influence of virulence factors for pathogenesis.}, subject = {Staphylococcus aureus}, language = {en} } @phdthesis{Sturm2015, author = {Sturm, Volker J{\"o}rg Friedrich}, title = {\(^{19}F\) Magnetresonanztomographie zur Bildgebung von Infektionen im Zeitverlauf}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122851}, school = {Universit{\"a}t W{\"u}rzburg}, pages = {114}, year = {2015}, abstract = {Im Rahmen dieser Arbeit sollten die M{\"o}glichkeiten der MR Tomographie erkundet werden bakterielle Infektionen im Zeitverlauf darzustellen. Genauer gesagt sollte das Potential der MR Tomographie anhand eines durch eine Infektion induzierten lokalisierten Abszesses unter Verwendung dreier unterschiedlicher MRT Methoden untersucht werden: Mittels nativem \(T_2\) Kontrast; der Verwendung von superparamagnetischen Eisenoxid Partieln (USPIO) als \(T_2^*\) Kontrastmittel; und dem Einsatz von Perfluorkarbonen (PFC) als \(^{19}F\) MRT Marker (siehe Kapitel 3). Wie erwartet f{\"u}hrte die durch die Infektion hervorgerufene Entz{\"u}ndung zu ver{\"a}nderten \(T_2\)-Zeiten, welche auf \(T_2\)-gewichteten MR Bildern eine Lokalisierung des Abszessbereiches erlauben. Jedoch eigneten sich diese Daten aufgrund der graduellen {\"A}nderung der \(T_2\)-Zeiten nicht, um eine klare Grenze zwischen Abszess und umliegendem Gewebe zu ziehen. Superparamagnetische Eisenoxidpartikel andererseit haben als MRT Kontrastmittel bereits in den letzten Jahren ihre F{\"a}higkeit unter Beweis gestellt Entz{\"u}ndungen [53, 58, 64] darzustellen. Die Anreicherung dieser Partikel am Rande des Abszesses [53], wie sie auch in unseren MR Daten zu beobachten war, erlaubte eine relativ scharfe Abgrenzung gegen{\"u}ber dem umgebenden Gewebe in der chronischen Phase der Infektion (Tag 9 p.i.). Hingegen gen{\"u}gte die nur sehr sp{\"a}rlichen Anreicherung von USPIO Partikeln in der akuten Phase der Infektion (Tag 3 p.i.) nicht f{\"u}r eine entsprechende Abgrenzung [58]. Aufgrund der sehr geringen biologischen H{\"a}ufigkeit und den sehr kurzen Relaxationszeiten von endogenem Fluor eignen sich Perfluorkarbone als Markersubstanz in der MR Tomographie von biologischen Systemen. Insbesondere da PFC Emulsionen durch phagozytierende Zellen aufgenommen werden und im Bereich von Entz{\"u}ndungen akkumulieren [30, 59]. In dieser Arbeit konnte anhand der erhaltenen MRT Daten eine Akkumulation von Perfluorkarbonen nicht nur in der chronischen Phase, sondern auch in der akuten Phase nachgewiesen werden. Diese Daten erlauben somit zu allen untersuchten Zeitpunkten eine Abgrenzung zwischen Infektion und umliegenden Gewebe. Aufgrund der besagten Vorteile wurden die Perfluorkarbone gew{\"a}hlt, um die M{\"o}glichkeiten der MR Tomographie zu testen, quantitative Informationen {\"u}ber die schwere der Infektion zu liefern. Als Referenz f{\"u}r die Bakterienbelastung wurden die Biolumineszenzbildgebung (BLI) [49, 50] und die Standardmethode zur Bestimmung der Bakterienbelastung cfu (koloniebildenden Einheiten) herangezogen. Eine Gegen{\"u}berstellung der zeitlichen Verl{\"a}ufe der durch die Biolumineszenzbildgebung und durch die cfu erhaltenen Daten liefert eine qualitative {\"U}bereinstimmung mit den durch die 19F MR Tomographie erhaltenen Daten. Dies trifft hierbei sowohl auf die {\"u}ber den gesamten Infektionsbereich hinweg summierten Signalamplituden, als auch auf das Volumen zu, in dem Fluor am Ort der Infektion akkumuliert wurde. Im Gegensatz zur Methode der cfu Bestimmung sind die MR Tomographie und die Biolumineszenzbildgebung nicht invasiv und erlauben die Verfolgung des Infektionsverlaufes an einem einzelnen Individuum. Hierzu ben{\"o}tigt, im Gegensatz zur MR Tomographie, die Methode der Biolumineszenzbildgebung jedoch einen speziellen Pathogenstamm. Dar{\"u}ber hinaus ist hervorzuheben, dass die MR Tomographie zudem die M{\"o}glichkeit bietet auch morphologische Informationen {\"u}ber den Infektionsbereich und seine Umgebung zu akquirieren. Gerade weil jede dieser Methoden die mit der Infektion einhergehenden Prozesse aus einer leicht anderen Blickrichtung betrachtet, erscheint es sinnvoll diese etablierte Untersuchungsplattform bestehend aus MRT, BLI und cfu {\"u}ber die in dieser Arbeit bearbeitete Fragestellung hinaus n{\"a}her zu untersuchen. Insbesondere der Aspekt inwieweit die drei Methoden sich gegenseitig erg{\"a}nzen, k{\"o}nnte einen tieferen Einblick in die Wechselwirkung zwischen Pathogen und Wirt erlauben. Auch wenn f{\"u}r die betrachtete Fragestellung bereits der hierdurchgef{\"u}hrte semiquanitative Ansatz zur Bestimmung der relativen Fluormengen am Ort der Infektion ausreichte, so ist doch im Allgemeinen w{\"u}nschenswert probenbezogen die Sensitivit{\"a}t der Spule und damit die G{\"u}te der Spulenabstimmung zu bestimmen. Hierzu ist jedoch die Aufnahme von \(B_1\)-Karten unabdingbar und wird entsprechend im Kapitel 4 \(Bloch-Siegert B_1^+-Mapping\) n{\"a}her addressiert. Der Schwerpunkt liegt hierbei, wie der Kapitelname bereits andeutet, auf der Bloch-Siegert Methode, die insbesondere in der pr{\"a}sentierten Implementierung in einer Turbo/ Multi Spin Echo Sequenz eine effiziente Nutzung der relativ langen \(T_\)2-Zeiten der Perfluorkarbone erlaubt. Da zudem die Bloch-Siegert-Methode eine rein phasenbasierte Methode ist, kann neben der aus den Daten erzeugten \(B_1\)-Karte zugleich ein unverf{\"a}lschtes Magnitudenbild generiert werden, wodurch eine sehr effiziente Nutzung der vorhandenen Messzeit erm{\"o}glicht wird. Diese Eigenschaft ist insbesondere f{\"u}r \(^{19}F\) Bildgebung von besonderem Interesse, da hier f{\"u}r jede Messung, aufgrund der {\"u}blicherweise relativ geringen Konzentration an Fluoratomen, lange Messzeiten ben{\"o}tigt werden. Zusammenfassend konnte anhand des untersuchten Tiermodells sowohl die F{\"a}higkeit der MR Tomographie nachgewiesen werden Infektionen im Zeitverlauf darzustellen, als auch die F{\"a}higkeit der MR Tomographie quantitative Informationen {\"u}ber den Verlauf der Infektion zu liefern. Desweiteren konnte eine M{\"o}glichkeit aufgezeigt werden, welche das Potential hat in vertretbarem Zeitrahmen auch in vivo B1+-Karten auf dem Fluorkanal zu erstellen und so einen zentralen Unsicherheitsfaktor, f{\"u}r Relaxometry und absolute Quantifizierung von \(^{19}F\) Daten in vivo, zu beseitigen.}, subject = {Kernspintomografie}, language = {de} } @article{WeibelBasseLuesebrinkHessetal.2013, author = {Weibel, Stephanie and Basse-Luesebrink, Thomas Christian and Hess, Michael and Hofmann, Elisabeth and Seubert, Carolin and Langbein-Laugwitz, Johanna and Gentschev, Ivaylo and Sturm, Volker J{\"o}rg Friedrich and Ye, Yuxiang and Kampf, Thomas and Jakob, Peter Michael and Szalay, Aladar A.}, title = {Imaging of Intratumoral Inflammation during Oncolytic Virotherapy of Tumors by \(^{19}\)F-Magnetic Resonance Imaging (MRI)}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0056317}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130311}, pages = {e56317}, year = {2013}, abstract = {Background Oncolytic virotherapy of tumors is an up-coming, promising therapeutic modality of cancer therapy. Unfortunately, non-invasive techniques to evaluate the inflammatory host response to treatment are rare. Here, we evaluate \(^{19}\)F magnetic resonance imaging (MRI) which enables the non-invasive visualization of inflammatory processes in pathological conditions by the use of perfluorocarbon nanoemulsions (PFC) for monitoring of oncolytic virotherapy. Methodology/Principal Findings The Vaccinia virus strain GLV-1h68 was used as an oncolytic agent for the treatment of different tumor models. Systemic application of PFC emulsions followed by \(^1H\)/\(^{19}\)F MRI of mock-infected and GLV-1h68-infected tumor-bearing mice revealed a significant accumulation of the \(^{19}\)F signal in the tumor rim of virus-treated mice. Histological examination of tumors confirmed a similar spatial distribution of the \(^{19}\)F signal hot spots and \(CD68^+\)-macrophages. Thereby, the \(CD68^+\)-macrophages encapsulate the GFP-positive viral infection foci. In multiple tumor models, we specifically visualized early inflammatory cell recruitment in Vaccinia virus colonized tumors. Furthermore, we documented that the \(^{19}\)F signal correlated with the extent of viral spreading within tumors. Conclusions/Significance These results suggest \(^{19}\)F MRI as a non-invasive methodology to document the tumor-associated host immune response as well as the extent of intratumoral viral replication. Thus, \(^{19}\)F MRI represents a new platform to non-invasively investigate the role of the host immune response for therapeutic outcome of oncolytic virotherapy and individual patient response.}, language = {en} } @article{HertleinSturmJakobetal.2013, author = {Hertlein, Tobias and Sturm, Volker and Jakob, Peter and Ohlsen, Knut}, title = {\(^{19}\)F Magnetic Resonance Imaging of Perfluorocarbons for the Evaluation of Response to Antibiotic Therapy in a Staphylococcus aureus Infection Model}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {5}, doi = {10.1371/journal.pone.0064440}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130113}, pages = {e64440}, year = {2013}, abstract = {Background The emergence of antibiotic resistant bacteria in recent decades has highlighted the importance of developing new drugs to treat infections. However, in addition to the design of new drugs, the development of accurate preclinical testing methods is essential. In vivo imaging technologies such as bioluminescence imaging (BLI) or magnetic resonance imaging (MRI) are promising approaches. In a previous study, we showed the effectiveness of \(^{19}\)F MRI using perfluorocarbon (PFC) emulsions for detecting the site of Staphylococcus aureus infection. In the present follow-up study, we investigated the use of this method for in vivo visualization of the effects of antibiotic therapy. Methods/Principal findings Mice were infected with S. aureus Xen29 and treated with 0.9\% NaCl solution, vancomycin or linezolid. Mock treatment led to the highest bioluminescence values during infection followed by vancomycin treatment. Counting the number of colony-forming units (cfu) at 7 days post-infection (p.i.) showed the highest bacterial burden for the mock group and the lowest for the linezolid group. Administration of PFCs at day 2 p.i. led to the accumulation of \(^{19}\)F at the rim of the abscess in all mice (in the shape of a hollow sphere), and antibiotic treatment decreased the \(^{19}\)F signal intensity and volume. Linezolid showed the strongest effect. The BLI, cfu, and MRI results were comparable. Conclusions \(^{19}\)F-MRI with PFCs is an effective non-invasive method for assessing the effects of antibiotic therapy in vivo. This method does not depend on pathogen specific markers and can therefore be used to estimate the efficacy of antibacterial therapy against a broad range of clinically relevant pathogens, and to localize sites of infection.}, language = {en} } @article{ElMajdoubHunscheIgressaetal.2015, author = {El Majdoub, Faycal and Hunsche, Stefan and Igressa, Alhadi and Kocher, Martin and Sturm, Volker and Maarouf, Mohammad}, title = {Stereotactic LINAC-Radiosurgery for Glomus Jugulare Tumors: A Long-Term Follow-Up of 27 Patients}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0129057}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151717}, pages = {e0129057}, year = {2015}, abstract = {Background The optimal treatment of glomus jugulare tumors (GJTs) remains controversial. Due to the critical location, microsurgery still provides high treatment-related morbidity and a decreased quality of life. Thus, we performed stereotactical radiosurgery (SRS) for the treatment of GJTs and evaluated the long-term outcome. Methods Between 1991 and 2011, 32 patients with GJTs underwent SRS using a linear accelerator (LINAC) either as primary or salvage therapy. Twenty-seven patients (median age 59.9 years, range 28.7-79.9 years) with a follow-up greater than five years (median 11 years, range 5.3-22.1 years) were selected for retrospective analysis. The median therapeutic single dose applied to the tumor surface was 15 Gy (range 11-20 Gy) and the median tumor volume was 9.5 ml (range 2.8-51 ml). Results Following LINAC-SRS, 10 of 27 patients showed a significant improvement of their previous neurological complaints, whereas 12 patients remained unchanged. Five patients died during follow-up due to old age or other, not treatment-related reasons. MR-imaging showed a partial remission in 12 and a stable disease in 15 patients. No tumor progression was observed. The actuarial overall survival rates after five, ten and 20 years were 100\%, 95.2\% and 79.4\%, respectively. Conclusions Stereotactic LINAC-Radiosurgery can achieve an excellent long-term tumor control beside a low rate of morbidity in the treatment of GJTs. It should be considered as an alternative therapy regime to surgical resection or fractionated external beam radiation either as primary, adjuvant or salvage therapy.}, language = {en} } @article{MaaroufNeudorferElMajdoubetal.2016, author = {Maarouf, Mohammad and Neudorfer, Clemens and El Majdoub, Faycal and Lenartz, Doris and Kuhn, Jens and Sturm, Volker}, title = {Deep Brain Stimulation of Medial Dorsal and Ventral Anterior Nucleus of the Thalamus in OCD: A Retrospective Case Series}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0160750}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166830}, pages = {e0160750}, year = {2016}, abstract = {Background The current notion that cortico-striato-thalamo-cortical circuits are involved in the pathophysiology of obsessive-compulsive disorder (OCD) has instigated the search for the most suitable target for deep brain stimulation (DBS). However, despite extensive research, uncertainty about the ideal target remains with many structures being underexplored. The aim of this report is to address a new target for DBS, the medial dorsal (MD) and the ventral anterior (VA) nucleus of the thalamus, which has thus far received little attention in the treatment of OCD. Methods In this retrospective trial, four patients (three female, one male) aged 31-48 years, suffering from therapy-refractory OCD underwent high-frequency DBS of the MD and VA. In two patients (de novo group) the thalamus was chosen as a primary target for DBS, whereas in two patients (rescue DBS group) lead implantation was performed in a rescue DBS attempt following unsuccessful primary stimulation. Results Continuous thalamic stimulation yielded no significant improvement in OCD symptom severity. Over the course of thalamic DBS symptoms improved in only one patient who showed "partial response" on the Yale-Brown Obsessive Compulsive (Y-BOCS) Scale. Beck Depression Inventory scores dropped by around 46\% in the de novo group; anxiety symptoms improved by up to 34\%. In the de novo DBS group no effect of DBS on anxiety and mood was observable. Conclusion MD/VA-DBS yielded no adequate alleviation of therapy-refractory OCD, the overall strategy in targeting MD/VA as described in this paper can thus not be recommended in DBS for OCD. The magnocellular portion of MD (MDMC), however, might prove a promising target in the treatment of mood related and anxiety disorders.}, language = {en} }