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7. Interplay of tau and functional network connectivity in progressive supranuclear palsy: a [18F]PI-2620 PET/MRI study.

Author

Aghakhanyan, Gayane, Rullmann, M., Rumpf, J., Schroeter, M. L., Scherlach, C., Patt, M., Brendel, M., Koglin, N., Stephens, A. W., Classen, J., Hoffmann, K. T., Sabri, O., and Barthel, H.

Subjects
PROGRESSIVE supranuclear palsy, TAU proteins, BRAIN function localization, MAGNETIC resonance imaging of the brain, TAUOPATHIES
Abstract

Purpose: Progressive supranuclear palsy (PSP) is primary 4-repeat tauopathy. Evidence spanning from imaging studies indicate aberrant connectivity in PSPs. Our goal was to assess functional connectivity network alterations in PSP patients and the potential link between regional tau-burden and network-level functional connectivity using the next-generation tau PET tracer [18F]PI-2620 and resting-state functional MRI (fMRI). Material and methods: Twenty-four probable PSP patients (70.9 ± 6.9 years, 13 female), including 14 Richardson syndrome (RS) and 10 non-RS phenotypes, underwent [18F]PI-2620 PET/MRI imaging. Distribution volume ratios (DVRs) were estimated using non-invasive pharmacokinetic modeling. Resting-state fMRI was also acquired in these patients as well as in thirteen older non-AD MCI reference group (64 ± 9 years, 4 female). The functional network was constructed using 141 by 141 region-to-region functional connectivity metrics (RRC) and network-based statistic was carried out (connection threshold p < 0.001, cluster threshold pFDR < 0.05). Results: In total, 9870 functional connections were analyzed. PSPs compared to aged non-AD MCI reference group expressed aberrant connectivity evidenced by the significant NBS network consisting of 89 ROIs and 118 connections among them (NBS mass 4226, pFDR < 0.05). Tau load in the right globus pallidus externus (GPe) and left dentate nucleus (DN) showed significant effects on functional network connectivity. The network linked with increased tau load in the right GPe was associated with hyperconnectivity of low-range intra-opercular connections (NBS mass 356, pFDR < 0.05), while the network linked with increased tau load in the left cerebellar DN was associated with cerebellar hyperconnectivity and cortico-cerebellar hypoconnectivity (NBS mass 517, pFDR < 0.05). Conclusions: PSP patients show altered functional connectivity. Network incorporating deep gray matter structures demonstrate hypoconnectivity, cerebellum hyperconnectivity, while cortico-cortical connections show variable changes. Tau load in the right GPe and left DN is associated with functional networks which strengthen low-scale intra-opercular and intra-cerebellar connections and weaken opercular-cerebellar connections. These findings support the concept of tau load-dependent functional network changes in PSP, by that providing evidence for downstream effects of neuropathology on brain functionality in this primary tauopathy. [ABSTRACT FROM AUTHOR]

Published
2022
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12. Accuracy and reproducibility of automated white matter hyperintensities segmentation with lesion segmentation tool: A European multi-site 3T study

Author

Ribaldi, F., Altomare, D., Jovicich, J., Ferrari, C., Picco, A., Pizzini, F. B., Soricelli, A., Mega, A., Ferretti, A., Drevelegas, A., Bosch, B., Muller, B. W., Marra, Camillo, Cavaliere, C., Bartres-Faz, D., Nobili, F., Alessandrini, F., Barkhof, F., Gros-Dagnac, H., Ranjeva, J. -P., Wiltfang, J., Kuijer, J., Sein, J., Hoffmann, K. -T., Roccatagliata, L., Parnetti, L., Tsolaki, M., Constantinidis, M., Aiello, M., Salvatore, M., Montalti, M., Caulo, M., Didic, M., Bargallo, N., Blin, O., Rossini, Paolo Maria, Schonknecht, P., Floridi, P., Payoux, P., Visser, P. J., Bordet, R., Lopes, R., Tarducci, R., Bombois, S., Hensch, T., Fiedler, U., Richardson, J. C., Frisoni, G. B., Marizzoni, M., Marra C. (ORCID:0000-0003-3994-4044), Rossini P. M. (ORCID:0000-0003-2665-534X), Ribaldi, F., Altomare, D., Jovicich, J., Ferrari, C., Picco, A., Pizzini, F. B., Soricelli, A., Mega, A., Ferretti, A., Drevelegas, A., Bosch, B., Muller, B. W., Marra, Camillo, Cavaliere, C., Bartres-Faz, D., Nobili, F., Alessandrini, F., Barkhof, F., Gros-Dagnac, H., Ranjeva, J. -P., Wiltfang, J., Kuijer, J., Sein, J., Hoffmann, K. -T., Roccatagliata, L., Parnetti, L., Tsolaki, M., Constantinidis, M., Aiello, M., Salvatore, M., Montalti, M., Caulo, M., Didic, M., Bargallo, N., Blin, O., Rossini, Paolo Maria, Schonknecht, P., Floridi, P., Payoux, P., Visser, P. J., Bordet, R., Lopes, R., Tarducci, R., Bombois, S., Hensch, T., Fiedler, U., Richardson, J. C., Frisoni, G. B., Marizzoni, M., Marra C. (ORCID:0000-0003-3994-4044), and Rossini P. M. (ORCID:0000-0003-2665-534X)

Abstract

Brain vascular damage accumulate in aging and often manifest as white matter hyperintensities (WMHs) on MRI. Despite increased interest in automated methods to segment WMHs, a gold standard has not been achieved and their longitudinal reproducibility has been poorly investigated. The aim of present work is to evaluate accuracy and reproducibility of two freely available segmentation algorithms. A harmonized MRI protocol was implemented in 3T-scanners across 13 European sites, each scanning five volunteers twice (test-retest) using 2D-FLAIR. Automated segmentation was performed using Lesion segmentation tool algorithms (LST): the Lesion growth algorithm (LGA) in SPM8 and 12 and the Lesion prediction algorithm (LPA). To assess reproducibility, we applied the LST longitudinal pipeline to the LGA and LPA outputs for both the test and retest scans. We evaluated volumetric and spatial accuracy comparing LGA and LPA with manual tracing, and for reproducibility the test versus retest. Median volume difference between automated WMH and manual segmentations (mL) was −0.22[IQR = 0.50] for LGA-SPM8, −0.12[0.57] for LGA-SPM12, −0.09[0.53] for LPA, while the spatial accuracy (Dice Coefficient) was 0.29[0.31], 0.33[0.26] and 0.41[0.23], respectively. The reproducibility analysis showed a median reproducibility error of 20%[IQR = 41] for LGA-SPM8, 14% [31] for LGA-SPM12 and 10% [27] with the LPA cross-sectional pipeline. Applying the LST longitudinal pipeline, the reproducibility errors were considerably reduced (LGA: 0%[IQR = 0], p < 0.001; LPA: 0% [3], p < 0.001) compared to those derived using the cross-sectional algorithms. The DC using the longitudinal pipeline was excellent (median = 1) for LGA [IQR = 0] and LPA [0.02]. LST algorithms showed moderate accuracy and good reproducibility. Therefore, it can be used as a reliable cross-sectional and longitudinal tool in multi-site studies.

Published
2021

23. Vascular white matter lesions negatively correlate with brain metastases in malignant melanoma - results from a retrospective comparative analysis

Author

Berk, B A, Hering, K, Kortmann, R-D, Hoffmann, K-T, Ziemer, M, and Seidel, C

Abstract

Brain metastasis (BM) is a major complication of different cancers. There is increasing evidence for influence of vascular factors on BM in patients with non-small cell lung cancer (NSCLC). It is not known if the same is true for other tumors that might rely on different forms of vasculogenesis. The objective of this retrospective study was to evaluate a possible negative association of vascular white matter lesions and vascular risk factors (vasRF) with brain metastases in patients with melanoma.

Published
2019

27. Differenzierung von ZNS-Läsionen der Enzephalomyelitis disseminata mittels suszeptibilitätsgewichteter Magnetresonanzbildgebung (SWI): Differenzierung von ZNS-Läsionen der Enzephalomyelitis disseminata mittels suszeptibilitätsgewichteter Magnetresonanzbildgebung (SWI)

Author

Hoffmann, K.–T., Schneider, J.– P., Hirsch, Franz Wolfgang, Gutberlet, Matthias, Medizinischen Fakultät der Universität Leipzig, Böttcher, Rene, Hoffmann, K.–T., Schneider, J.– P., Hirsch, Franz Wolfgang, Gutberlet, Matthias, Medizinischen Fakultät der Universität Leipzig, and Böttcher, Rene

Abstract

Die Magnetresonanztomographie stellt für die Detektion von zerebralen und spinalen Läsionen bei der Multiplen Sklerose die sensitivste bildgebende Methode dar und ist ein Instrument, die räumliche und zeitliche Dissemination der Erkrankung abbilden zu können. Die Spezifität des Verfahrens ist aber gering und die Applikation von MR-Kontrastmittel bei der Diagnostik zwingend notwendig. Bei der suszeptibilitätsgewichteten Magnetresonanzbildgebung (SWI) handelt sich um ein MR-Verfahren, das Schwankungen der magnetischen Suszeptibilität in der Gradientenechosequenz nutzt, um einen Bildkontrast zu erzeugen. Dadurch ist es möglich, hochaufgelöst und sensitiv Magnetfeldinhomogenitäten zu detektieren. In der vorliegenden prospektiven Studie wurden im Zeitraum von 2010 bis 2013 MRT-Untersuchungen unter Einschluss der suszeptibilitätsgewichteten Bildgebung in einem Kollektiv von 41 Patienten (33 weiblich, 8 männlich;; Durchschnittsalter 40 Jahre) mit gesicherter Multipler Sklerose und einem Vergleichskollektiv von 43 Patienten (28 weiblich, 15 männlich;; Durchschnittsalter 45 Jahre), bei denen weder bildgebend noch klinisch Hinweise auf eine Multiple Sklerose vorlagen, durchgeführt. Die Untersuchung wurde mit einem 1,5-Tesla-Magnetresonanz- tomographen realisiert. Das besondere wissenschaftliche Interesse galt dabei der „normal erscheinenden weißen Substanz“ (NAWM) und den zerebralen Läsionen. In der FLAIR-Sequenz wurden die MS-Läsionen und ROIs detektiert und markiert. Anschließend erfolgte die Übertragung in gleicher Schichthöhe auf die SWI-, T1w- und ADC-Sequenz. Zur Differenzierung von akuten und chronischen Läsionen erfolgte im Untersuchungsablauf die intravenöse Gabe von Gadolinium-DTPA- Kontrastmittel. Schon längere Zeit werden im wissenschaftlichen Diskurs krankheitsspezifische Veränderungen in der NAWM vor Auftreten der MS-Läsionen vermutet. Die Sensitivität der FLAIR-Sequenz ist aber scheinbar unzureichend. Mit der SWI- Bildgebung konnten statistisch signifikante SI

Published
2017

28. Outcome of Surgical or Endovascular Treatment of Giant Intracranial Aneurysms, with Emphasis on Age, Aneurysm Location, and Unruptured Aneuryms - A Systematic Review and Meta-Analysis

Author

Dengler, Julius, Maldaner, Nicolai, Maldaner, N., van der Zwan, A., van Doormaal, T., Cognard, C., Gawlitza, M., Walter, J., Kalff, R., Fiedler, J., Uebelacker, A., Dengler, J., Bohner, G., Wiener, E., Bauknecht, H. C., Heuschmann, P. U., Malzahn, U., Gläsker, S., Zentner, J., Gläsker, Sven, Van Velthoven, V., Guhl, S., Schroeder, H. W. S., Strowitzki, M., Etminan, N., Haengghi, D., Eicker, S., Turowski, B., Schebesch, K. M., Brawanski, A., Endres, Matthias, Wrede, K., Sure, U., Schmidt, N. O., Regelsberger, J., Westphal, M., Mielke, D., Rohde, V., Hosch, H., Moskopp, D., Joedicke, A., Wagner, Martin, Hohaus, C., Meisel, H. J., Wostrack, M., Meyer, B., Lehmberg, J., Musahl, C., Hopf, N., Winkler, G., Spetzger, U., Graewe, A., Malzahn, Uwe, Meier, U., Hong, B., Nakamura, M., Krauss, J., Grote, A., Simon, M., Schramm, J., Kursumovic, A., Rath, S. A., Marbacher, S., Heuschmann, Peter U, Fathi, A., Fandino, J., Familiari, P., Raco, A., Bijlenga, P., Schaller, K., Gruber, A., Wang, W. T., Knosp, E., Hoffmann, K. T., Vajkoczy, Peter, Boxhammer, E., Rüfenacht, D. A., Wanke, I., Boccardi, E., Piano, M., Niemelä, M., Nurminen, V., Lehecka, M., Hernesniemi, J., Burkhardt, J. K., Group, Giant Intracranial Aneurysm Study, Bozinov, O., Regli, L., Shekhtman, O. D., Eliava, S. S., Kato, N., Irie, K., Nishimura, K., Kaku, S., Arakawa, H., Yuki, I., Vajkoczy, P., Ishibashi, T., Murayama, Y., Fiss, I., Kombos, T., Pedro, M. T., König, R., Wirtz, R., Brand, C., Hagel, V., Helthuis, J., Surgical clinical sciences, University of Zurich, and Dengler, Julius

Subjects
methods [Embolization, Therapeutic], medicine.medical_treatment, Review, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, Medicine, Giant intracranial aneurysm, Embolization, Research Support, Non-U.S. Gov't, surgery [Intracranial Aneurysm], Embolization, Therapeutic, 2728 Neurology (clinical), Treatment Outcome, Neurology, Endovascular procedures, Meta-analysis, Internal carotid artery, Therapeutic, Cardiology and Cardiovascular Medicine, Carotid Artery, Internal, medicine.medical_specialty, pathology [Intracranial Aneurysm], Surgical aneurysm treatment, MEDLINE, 610 Medicine & health, surgery [Carotid Artery, Internal], 2705 Cardiology and Cardiovascular Medicine, 03 medical and health sciences, 10180 Clinic for Neurosurgery, Aneurysm, medicine.artery, Humans, Endovascular treatment, ddc:610, Retrospective Studies, business.industry, Retrospective cohort study, Intracranial Aneurysm, medicine.disease, Internal, Surgery, ddc:616.8, Clinical trial, meta-analysis, pathology [Carotid Artery, Internal], 2808 Neurology, Endovascular Procedures, Neurology (clinical), Carotid Artery, business, 030217 neurology & neurosurgery, methods [Endovascular Procedures]
Abstract

Background: Designing treatment strategies for unruptured giant intracranial aneurysms (GIA) is difficult as evidence of large clinical trials is lacking. We examined the outcome following surgical or endovascular GIA treatment focusing on patient age, GIA location and unruptured GIA. Methods: Medline and Embase were searched for studies reporting on GIA treatment outcome published after January 2000. We calculated the proportion of good outcome (PGO) for all included GIA and for unruptured GIA by meta-analysis using a random effects model. Results: We included 54 studies containing 64 study populations with 1,269 GIA at a median follow-up time (FU-T) of 26.4 months (95% CI 10.8-42.0). PGO was 80.9% (77.4-84.4) in the analysis of all GIA compared to 81.2% (75.3-86.1) in the separate analysis of unruptured GIA. For each year added to patient age, PGO decreased by 0.8%, both for all GIA and unruptured GIA. For all GIA, surgical treatment resulted in a PGO of 80.3% (95% CI 76.0-84.6) compared to 84.2% (78.5-89.8, p = 0.27) after endovascular treatment. In unruptured GIA, PGO was 79.7% (95% CI 71.5-87.8) after surgical treatment and 84.9% (79.1-90.7, p = 0.54) after endovascular treatment. PGO was lower in high quality studies and in studies presenting aggregate instead of individual patient data. In unruptured GIA, the OR for good treatment outcome was 5.2 (95% CI 2.0-13.0) at the internal carotid artery compared to 0.1 (0.1-0.3, p < 0.1) in the posterior circulation. Patient sex, FU-T and prevalence of ruptured GIA were not associated with PGO. Conclusions: We found that the chances of good outcome after surgical or endovascular GIA treatment mainly depend on patient age and aneurysm location rather than on the type of treatment conducted. Our analysis may inform future research on GIA.

Published
2016

29. Perianeurysmal edema in giant intracranial aneurysms in relation to aneurysm location, size, and partial thrombosis

Author

Dengler, Julius, Maldaner, Nicolai, Bijlenga, Philippe, Burkhardt, Jan-Karl, Graewe, Alexander, Guhl, Susanne, Hong, Bujung, Hohaus, Christian, Kursumovic, Adisa, Mielke, Dorothee, Schebesch, Karl-Michael, Wostrack, Maria, Rufenacht, Daniel, Vajkoczy, Peter, Schmidt, Nils Ole, Vajkoczy, P, Maldaner, N, Uebelacker, A, Dengler, J, Endres, M, Bohner, G, Wiener, E, Bauknecht, H C, Heuschmann, P U, Malzahn, U, Gläsker, S, Zentner, J, Van Velthoven, V, Guhl, S, Schroeder, Werner, Strowitzki, M, Etminan, N, Haengghi, D, Eicker, S, Turowski, B, Schebesch, K M, Brawanski, A, Wrede, Karsten, Sure, Ulrich, Schmidt, N O, Regelsberger, J, Westphal, M, Mielke, D, Rohde, V, Hosch, H, Moskopp, D, Joedicke, A, Hohaus, C, Meisel, H J, Wostrack, M, Meyer, B, Lehmberg, J, Musahl, C, Hopf, N, Winkler, G, Spetzger, U, Graewe, A, Meier, U, Hong, B, Nakamura, M, Krauss, J, Grote, A, Simon, M, Schramm, J, Kursumovic, A, Rath, S A, Marbacher, S, Fathi, A, Fandino, J, Familiari, P, Raco, A, Bijlenga, P, Schaller, K, Gruber, A, Wang, W T, Knosp, E, Hoffmann, K T, Boxhammer, E, Rüfenacht, Daniel, Boccardi, E, Piano, M, Niemelä, M, Nurminen, V, Lehecka, M, Hernesniemi, J, Burkhardt, J K, Bozinov, O, Regli, L, Shekhtman, O D, Eliava, S S, Kato, N, Irie, K, Nishimura, K, Kaku, S, Arakawa, H, Yuki, I, Ishibashi, T, Murayama, Y, Fiss, I, Kombos, T, Pedro, M T, König, R, Wirtz, R, Helthuis, J, van der Zwan, A, Cognard, C, Gawlitza, M, Wanke, Isabel, Fiedler, J, Surgical clinical sciences, University of Zurich, and Dengler, Julius

Subjects
Aneurysm volume, Adult, Male, medicine.medical_specialty, animal structures, Perianeurysmal edema, Clinical Neurology, Medizin, 610 Medicine & health, Brain Edema, Giant intracranial aneurysm, Partially thrombosed aneurysm, Vascular disorders, Aged, Female, Humans, Intracranial Aneurysm, Magnetic Resonance Imaging, Middle Aged, Retrospective Studies, Thrombosis, Surgery, Medicine (all), Neurology (clinical), Imaging data, 10180 Clinic for Neurosurgery, Aneurysm, medicine.artery, Edema, medicine, 10. No inequality, medicine.diagnostic_test, business.industry, Research Support, Non-U.S. Gov't, Magnetic resonance imaging, medicine.disease, 2746 Surgery, ddc:616.8, Giant Intracranial Aneurysm, 2728 Neurology (clinical), Middle cerebral artery, Radiology, Internal carotid artery, medicine.symptom, business, Partial thrombosis
Abstract

OBJECT The underlying mechanisms causing intracranial perianeurysmal edema (PAE) are still poorly understood. Since PAE is most frequently observed in giant intracranial aneurysms (GIAs), the authors designed a study to examine the occurrence of PAE in relation to the location, size, and partial thrombosis (PT) of GIAs along with the clinical impact of PAE. METHODS Magnetic resonance imaging data for patients with a diagnosis of unruptured GIA from the international multicenter Giant Intracranial Aneurysm Registry were retrospectively analyzed with regard to location and size of the GIA, PAE volume, and the presence of PT. The occurrence of PAE was correlated to clinical findings. RESULTS Imaging data for 69 GIAs were eligible for inclusion in this study. Perianeurysmal edema was observed in 33.3% of all cases, with the highest frequency in GIAs of the middle cerebral artery (MCA; 68.8%) and the lowest frequency in GIAs of the cavernous internal carotid artery (ICA; 0.0%). Independent predictors of PAE formation were GIA volume (OR 1.13, p = 0.02) and the occurrence of PT (OR 9.84, p = 0.04). Giant intracranial aneurysm location did not predict PAE occurrence. Giant aneurysms with PAE were larger than GIAs without PAE (p < 0.01), and GIA volume correlated with PAE volume (rs = 0.51, p = 0.01). Perianeurysmal edema had no influence on the modified Rankin Scale score (p = 0.30 or the occurrence of aphasia (p = 0.61) or hemiparesis (p = 0.82). CONCLUSIONS Perianeurysmal edema was associated with GIA size and the presence of PT. As no PAE was observed in cavernous ICA aneurysms, even though they exerted mass effect on the brain and also displayed PT, the dura mater may serve as a barrier protecting the brain from PAE formation.

Published
2015

34. Choroidal hemangioma: MR findings and differentiation from uveal melanoma

Author

Stroszczynski, C, Hosten, N, Bornfeld, N, Wiegel, T, Schueler, A, Foerster, P, Lemke, A J, Hoffmann, K T, and Felix, R

Subjects
Adult, Gadolinium DTPA, Male, Uveal Neoplasms, Adolescent, Choroid, Choroid Neoplasms, Contrast Media, Middle Aged, Magnetic Resonance Imaging, Sensitivity and Specificity, eye diseases, Diagnosis, Differential, Journal Article, Humans, Female, sense organs, Child, Hemangioma, Uvea, Melanoma
Abstract

BACKGROUND AND PURPOSE: The aim of this study was to establish the MR imaging characteristics of choroidal hemangioma and to compare them with those of uveal melanoma. METHODS: Among 41 patients examined at 1.5 T (4-cm surface coil, T1-weighted and fast spin-echo T2-weighted sequences), 25 had uveal melanoma and 16 had circumscribed choroidal hemangioma. After i.v. bolus injection of gadopentetate dimeglumine, dynamic and T1-weighted sequences were acquired. RESULTS: In patients with choroidal hemangioma, uniform signal characteristics were detected on fast T2-weighted images. In 15 of 16 patients with choroidal hemangioma, lesions were isointense with vitreous on fast spin-echo T2-weighted images, whereas lesions in 24 of 25 patients with uveal melanoma were hypointense. Signal characteristics of uveal melanoma and hemangioma did not differ significantly on plain T1-weighted images. Enhancement was earlier and much stronger for circumscribed choroidal hemangioma than for uveal melanoma. After i.v. bolus application of gadopentetate dimeglumine, the increase of signal intensity was higher for circumscribed choroidal hemangioma (signal intensity ratio, 5.8) than for uveal melanoma (signal intensity ratio, 2.2). CONCLUSION: Circumscribed choroidal hemangioma may be difficult to differentiate from melanoma by ophthalmologic examination. Differentiation may not be possible if direct viewing of uveal space-occupying lesions is hampered by opaque vitreous media. The characteristic findings on fast spin-echo T2-weighted MR images and early enhanced images aid in differentiating choroidal hemangioma from uveal melanoma.

Published
1998

36. Embolization of experimental wide-necked aneurysms with iodine-containing polyvinyl alcohol solubilized in a low-angiotoxicity solvent

Author

Dudeck, O., Jordan, O., Hoffmann, K. T., Okuducu, A. F., Husmann, I., Kreuzer-Nagy, T., Tesmer, K., Podrabsky, P., Bruhn, H., Hilborn, Jöns, Rüfenacht, D. A., Doelker, E., Felix, R., Dudeck, O., Jordan, O., Hoffmann, K. T., Okuducu, A. F., Husmann, I., Kreuzer-Nagy, T., Tesmer, K., Podrabsky, P., Bruhn, H., Hilborn, Jöns, Rüfenacht, D. A., Doelker, E., and Felix, R.

Abstract

BACKGROUND AND PURPOSE: To evaluate the ready-to-use iodine-containing polyvinyl alcohol (I-PVA) dissolved in the low angiotoxic solvent N-methyl pyrrolidone (NMP) for embolization of porcine wide-necked aneurysms. METHODS: Fourteen broad-based carotid sidewall aneurysms were surgically constructed in 7 swine. I-PVA (40%) in NMP was injected under temporary balloon occlusion bridging the aneurysm neck. After 4 weeks, follow-up angiography, multisection CT angiography (MSCTA), and 3T MR imaging including MR angiography (MRA) sequences were performed. Afterward, harvested aneurysms were investigated histopathologically. RESULTS: The liquid embolic was well visible under fluoroscopy and displayed a favorable precipitation pattern, allowing for controlled polymer delivery. Ten aneurysms (71%) were initially completely occluded, whereas in 1 aneurysm, a minimal polymer leakage was observed. The other 4 aneurysms (29%) were almost completely occluded. One animal suffered a lethal rebleeding from the anastomosis after uneventful embolization. Aneurysms embolized with I-PVA could be discriminated well from the parent artery without beam-hardening artifacts on MSCTA, and no susceptibility artifacts were encountered on MR imaging. Histologic examination revealed all aneurysms covered with a membrane of fibroblasts and an endothelial cell layer while a moderate intraaneurysmal inflammatory response to the polymer was observed. CONCLUSION: I-PVA dissolved in NMP has proved its effectiveness for the embolization of experimental wide-necked aneurysms. This precipitating liquid embolic offers several interesting features in that it needs no preparation before use and no radiopaque admixtures, the latter allowing for artifact-free evaluation of treated aneurysms with MSCTA and MRA. Moreover, it uses NMP as a solvent, which has only a low angiotoxicity.

Published
2006

37. Protonen-Magnet-Resonanz-Spektroskopie (1 H-MRS) mit 3,0 Tesla zur Erfassung cerebraler Metabolite im Frontalhirn depressiver Patienten unter Plazebo-kontrollierter Inositolgabe im Vergleich zu gesunden Probanden

Author

Heinz, A., Hoffmann, K.-T., Bodamer, O., Reinfried, Lutz, Heinz, A., Hoffmann, K.-T., Bodamer, O., and Reinfried, Lutz

Abstract

Ziele: Mittels absolutquantifizierender Protonen-Magnet-Resonanz-Spektroskopie (1H-MRS) wollten wir das Ergebnis einer Vorstudie bestätigen, die im Frontallappen einen reduzierten Quotienten von myo-Inositol/Gesamtcreatin (mI/tCr) bei Depressiven fand. Darüber hinaus testeten wir den antidepressiven Effekt von Inositol als Add-on-Therapie. Methodik: Wir untersuchten Einzelvoxel (2 x 2 x 2 cm3) in der weißen Substanz der rechten und linken Präfrontalregion mit Hilfe eines 3-Tesla Bruker Medspec Systems (STEAM Sequenz, TR/TE/TM = 6000/20/30 ms). Die einzelnen Metabolite wurden anhand des cerebralen Wassers als internem Standard quantifiziert (nach dem LCModell). Es wurden 24 unmedizierte Patienten mit unipolaren depressiven Episoden mit 24 alters- und geschlechtsgematchten gesunden Kontrollen verglichen. In doppelblindem, Plazebo-kontrollierten Parallelgruppen-Design erhielten die Patienten täglich 18 Gramm Inositol oder Plazebo zusätzlich zu Citalopram über vier Wochen. Ergebnisse: An der Baseline unterschieden sich die mI-, Cholin- und N-Acetyl-Aspartat-Konzentrationen der Patienten nicht von jenen der Kontrollen. Es fanden sich keine sich keine signifikanten Unterschiede zwischen Inositol- und Plazebo-Gruppe. Überraschenderweise zeigten die depressiven Patienten an der Baseline gegenüber den Kontrollen signifikant höhere tCr-Konzentrationen (mmol/kg) links (5,57 ± 0,96 vs. 4,87 ± 0,63; + 15 %, p < 0,01) und rechts präfrontal (5,29 ± 0,92 vs. 4,46 ± 0,41; + 17 %, p < 0,01). Nach der Behandlung ergab sich eine Reduktion der tCr-Konzentration links- (Tag 28: 5,05 ± 1,16; – 12 %, p = 0,08) und rechtsfrontal (Tag 28: 4,61 ± 1,07; – 9 %, p = 0,09). Die tCr-Konzentrationen der Patienten am Tag 28 unterschieden sich nicht mehr von jenen der Kontrollen. Zusammenfassung: Wir zeigten eine reversible Steigerung der tCr-Konzentration der Patienten im Vergleich zu Kontrollen, die auf Veränderungen des Creatin-Transports oder der ATP-Synthese bei unmedizierter unipolarer Depressi, Objectives: By means of proton magnetic resonance spectroscopy (1H-MRS) with absolute quantification we wanted to confirm our previous finding of decreased ratios of the metabolites myo-Inositol/total creatine (mI/tCr) in the right frontal brain of depressives. Moreover, we tested the antidepressive effect of oral Inositol ingestion as add-on-therapy. We measured concentrations (mmol/kg ww) of mI, tCr (= Creatine + Phosphocreatine), Choline (Cho) and N-Acetyl-Aspartate (NAA) in the frontal brain. Methods: Single voxels (2x2x2 cm3) in the white matter of the left and right prefrontal region were examined in a three Tesla Bruker Medspec System (STEAM sequence, TR/TE/TM = 6000/20/30 ms). Metabolites were quantified using the LCModel. At baseline, 24 drug-free patients with unipolar depressive episodes were compared to 24 age and sex matched healthy controls. In a double blind, placebo controlled parallel-group design patients received daily 18 grams Inositol or placebo as an add on therapy to Citalopram over four weeks. Results: At baseline, mI, Cho and NAA concentrations showed no significant differences between patients and controls. The treatment with Inositol did not result in any significant differences to the treatment with placebo. Surprisingly the patients showed significant higher tCr concentrations in the left (5.57 ± 0.96 vs. 4.87 ± 0.63; + 15 %, p < 0.01) as well as in the right prefrontal region (5.29 ± 0.92 vs. 4.46 ± 0.41; + 17 %, p < 0.01) compared to controls. The treatment caused a trend towards a decrease of tCr in the left (day 28: 5.05 ± 1.16; – 12 %, p = 0.08) and in the right frontal hemisphere (day 28: 4.61 ± 1.07; – 9 %, p = 0.09) compared to baseline. The differences between the patients’ tCr at day 28 and the tCr of controls were no more significant. Conclusion: We have found a state dependent increase of tCr concentration indicating bifrontal deviations in Creatine transport or ATP synthesis in drug free unipolar depressives.

Published
2006

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