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Keller S, Sedlacik J, Schuler T, Buchert R, Avanesov M, Zenouzi R, Lohse AW, Kooijman H, Fiehler J, Schramm C, Yamamura J. Prospective comparison of diffusion-weighted MRI and dynamic Gd-EOB-DTPA-enhanced MRI for detection and staging of hepatic fibrosis in primary sclerosing cholangitis. Eur Radiol 2018; 29:818-828. [PMID: 30014204 DOI: 10.1007/s00330-018-5614-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/26/2018] [Accepted: 06/15/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To assess the diagnostic value of multiparametric magnetic resonance imaging (MRI) including dynamic Gd-EOB-DTPA-enhanced (DCE) and diffusion-weighted (DW) imaging for diagnosis and staging of hepatic fibrosis in primary sclerosing cholangitis (PSC) using transient elastography as a standard reference. MATERIAL AND METHODS Multiparametric MRI was prospectively performed on a 3.0-Tesla scanner in 47 patients (age 43.9±14.3 years). Transient elastography derived liver stiffness measurements (LSM), DCE-MRI derived parameters (hepatocellular uptake rate (Ki), arterial (Fa), portal venous (Fv) and total (Ft) blood flow, mean transit time (MTT), and extracellular volume (Ve)) and the apparent diffusion coefficient (ADC) were calculated. Correlation and univariate analysis of variance with post hoc pairwise comparison were applied to test for differences between LSM derived fibrosis stages (F0/F1, F2/3, F4). ROC curve analysis was used as a performance measure. RESULTS Both ADC and Ki correlated significantly with LSM (r= -0.614; p<0.001 and r= -0.368; p=0.01). The ADC significantly discriminated fibrosis stages F0/1 from F2/3 and F4 (p<0.001). Discrimination of F0/1 from F2/3 and F4 reached a sensitivity/specificity of 0.917/0.821 and 0.8/0.929, respectively. Despite significant inter-subject effect for classification of fibrosis stages, post hoc pairwise comparison was not significant for Ki (p>0.096 for F0/1 from F2/3 and F4). LSM, ADC and Ki were significantly associated with serum-based liver functional tests, disease duration and spleen volume. CONCLUSION DW-MRI provides a higher diagnostic performance for detection of hepatic fibrosis and cirrhosis in PSC patients in comparison to Gd-EOB-DTPA-enhanced DCE-MRI. KEY POINTS • Both ADC and hepatocellular uptake rate (Ki) correlate significantly with liver stiffness (r= -0.614; p<0.001 and r= -0.368; p=0.01). • The DCE-imaging derived quantitative parameter hepatocellular uptake rate (Ki) fails to discriminate pairwise intergroup differences of hepatic fibrosis (p>0.09). • DWI is preferable to DCE-imaging for discrimination of fibrosis stages F0/1 to F2/3 (p<0.001) and F4 (p<0.001).
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Affiliation(s)
- S Keller
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany. .,Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany.
| | - J Sedlacik
- Department of Neuroradiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - T Schuler
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany
| | - R Buchert
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany
| | - M Avanesov
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany
| | - R Zenouzi
- 1st Department of Medicine, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - A W Lohse
- 1st Department of Medicine, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - H Kooijman
- Philips Medical Systems, MR Clinical Science, Hamburg, Germany
| | - J Fiehler
- Department of Neuroradiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - C Schramm
- 1st Department of Medicine, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - J Yamamura
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany
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Kammer NN, Coppenrath E, Treitl KM, Kooijman H, Dietrich O, Saam T. Comparison of contrast-enhanced modified T1-weighted 3D TSE black-blood and 3D MP-RAGE sequences for the detection of cerebral metastases and brain tumours. Eur Radiol 2015; 26:1818-25. [PMID: 26334511 DOI: 10.1007/s00330-015-3975-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/24/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To compare a modified T1-weighted 3D TSE black-blood sequence with sub-millimetre resolution (T1-mVISTA) with a magnetization-prepared rapid gradient echo (MP-RAGE) sequence for the diagnosis of cerebral malignomas. METHODS Forty-six patients with known or suspected intracranial tumours and 15 control patients were included in this retrospective study. All patients underwent T1-mVISTA (0.75-mm isotropic resolution, 4:43 min) and MP-RAGE (0.8-mm isotropic resolution, 4:46 minutes) at 3-Tesla in random order after application of contrast agent. Two experienced radiologists determined the number of lesions. Maximum diameter, diagnostic confidence (DC), visual assessment of contrast enhancement (VCE) and CNRlesion/parenchyma were assessed for each lesion. RESULTS Significantly more lesions were detected with T1-mVISTA compared to the MP-RAGE (61 vs. 36; p < 0.05). Further, DC and VCE was rated significantly higher in the T1-mVISTA (p < 0.05 and p < 0.001). Mean CNRlesion/parenchyma was twofold higher for T1-mVISTA (24.2 ± 17.5 vs. 12.7 ± 11.5, p < 0.001). The 25 lesions detected only in T1-mVISTA were significantly smaller than those detected in both sequences (4.3 ± 3.7 mm vs. 11.3 ± 10.7 mm; p < 0.01). CONCLUSIONS T1-mVISTA increases the contrast of lesions significantly compared to MP-RAGE and might therefore improve detection rates of small lesions in early stages of disease. KEY POINTS • T1-mVISTA leads to significantly higher contrast-to-noise ratios of cerebral malignomas. • T1-mVISTA detects significantly more metastatic lesions compared to 3D-MPRAGE. • Lesions detected only by T1-mVISTA are smaller than those detected in both sequences. • Diagnostic confidence is significantly higher for lesions detected by T1-mVISTA. • Application of T1-mVISTA might be of high relevance in early stages of disease.
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Affiliation(s)
- N N Kammer
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstr. 20, 80336, Munich, Germany.
| | - E Coppenrath
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstr. 20, 80336, Munich, Germany
| | - K M Treitl
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstr. 20, 80336, Munich, Germany
| | - H Kooijman
- Philips Healthcare, Luebeckertordamm 5, 20099, Hamburg, Germany
| | - O Dietrich
- Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr 15, 81377, Munich, Germany
| | - T Saam
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstr. 20, 80336, Munich, Germany
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Saam T, Maurus S, Kammer N, Kooijman H, Treitl M, Reiser M, Coppenrath E, Treitl K. Atem-getriggertes 3D-T1w-Black-Blood-MRT für die Diagnose der thorakalen Großgefäßvaskulitis: Eine Machbarkeitsstudie. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1550969] [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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Kammer N, Coppenrath E, Treitl K, Kooijman H, Reiser M, Saam T. 3D T1w-Black-Blood MRT in der Diagnostik zerebraler Metastasen bei 3.0 Tesla. ROFO-FORTSCHR RONTG 2015. [DOI: 10.1055/s-0035-1551332] [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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Kammer N, Coppenrath E, Kooijman H, Reiser MF, Saam T. Whole Brain 3D-Black-Blood 3T-MRI: Eine Pilotstudie in der bildgebenden Diagnostik zerebraler Vaskulitiden. ROFO-FORTSCHR RONTG 2014. [DOI: 10.1055/s-0034-1372906] [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: 10/25/2022]
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Kording F, Schoennagel B, Much C, Ueberle F, Kooijman H, Yamamura J, Adam G, Wedegaertner U. MRT-Herzbildgebung mit neuem Triggerverfahren: MR kompatibles Doppler Ultraschall Gerät im Vergleich zum EKG. ROFO-FORTSCHR RONTG 2013. [DOI: 10.1055/s-0033-1346293] [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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Regier M, Schwarz D, Derlin T, Kooijman H, Hennigs J, Klose H, Adam G. Diffusionsgewichtete MRT und FDG-PET des nicht kleinzelligen Bronchialkarzinoms (NSCLC): Korreliert der Apparent Diffusion Coefficient (ADC) mit der Stoffwechselaktivität (SUV)? ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221584] [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: 10/20/2022]
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Wedegärtner U, Yamamura J, Frisch M, Kooijman H, Huff A, Hecher K, Adam G. In-vivo Messungen der fetalen Blutsauerstoffsättigung im fetalen Schaf: eine Machbarkeitsstudie. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221261] [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: 10/20/2022]
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Yamamura J, Frisch M, Schnackenburg B, Kooijman H, Adam G, Wedegärtner U. MR Angiographie der fetalen Gefäße mit cardialer Triggerung: eine Machbarkeitsstudie am Schafsmodell. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221321] [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: 10/20/2022]
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Buerke B, Bremer C, Kooijman H, Tombach B, Heindel W, Allkemper T. Bestimmung der optimalen „Keyhole-Percentage“ für die hochaufgelöste, kontrastmittelgestützte 3D-Keyhole-MRA: Ergebnisse einer experimentellen Studie. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221604] [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: 10/20/2022]
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Frisch MF, Yamamura J, Kooijman H, Hecher K, Adam G, Wedegärtner U. Funktionelle MR-Bildgebung an fetalen Lämmern am 1,5T und 3,0T: Signaländerungen von delta R2* im fetalen Gehirn und Lunge unter Hypoxie. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221268] [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: 10/20/2022]
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Schreiter D, Ries T, Begemann PG, Kooijman H, Brandl S, Klose H, Adam G, Regier M. Diffusionsgewichtete MRT mit Unterdrückung des Hintergrundsignals (DWIBS) zur Detektion von Lungenrundherden bei 1,5 Tesla: Erste Ergebnisse. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073590] [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: 10/21/2022]
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Regier M, Schreiter D, Kooijman H, Kaul MG, Begemann PG, Brandl S, Klose H, Adam G. Stellenwert der Diffusionsgewichteten Bildgebung in der Differenzierung histologischer Subtypen des Brochialkarzinoms. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073520] [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: 10/21/2022]
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Habermann CR, Gossrau P, Kooijman H, Graessner J, Cramer MC, Kaul MG, Reitmeier F, Jaehne M, Adam G. Monitoring of gustatory stimulation of salivary glands by diffusion-weighted MR imaging: comparison of 1.5T and 3T. AJNR Am J Neuroradiol 2007; 28:1547-51. [PMID: 17846209 PMCID: PMC8134380 DOI: 10.3174/ajnr.a0587] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND PURPOSE Our aim was to compare different field strengths monitoring physiologic changes due to oral stimulation of parotid glands by using diffusion-weighted (DW) echo-planar imaging (EPI). MATERIALS AND METHODS Twenty-seven healthy volunteers were examined with a DW-EPI sequence at 1.5T and 3T before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1000 s/mm(2). Apparent diffusion coefficient (ADC) maps were evaluated with a manually placed region of interest including the entire parotid gland. For comparison of results, a Student t test was used on the basis of the mean of the volunteer median values. To compare both field strengths, we calculated the Pearson correlation coefficient (r). RESULTS DW-EPI MR imaging visualized the parotid glands of all volunteers. With 1.5T, the mean ADC before stimulation was 1.12 x 10(-3) mm(2)/s +/- 0.08 x 10(-3) mm(2)/s. After stimulation with lemon juice, the ADC increased to 1.18 x 10(-3) mm(2)/s +/- 0.09 x 10(-3) mm(2)/s. For 3T, the ADC before stimulation was 1.14 x 10(-3) mm(2)/s +/- 0.04 x 10(-3) mm(2)/s, with an increase to 1.17 x 10(-3) mm(2)/s +/- 0.05 x 10(-3) mm(2)/s after stimulation. For both field strengths, the increase in ADC after stimulation was significant (P < .001). High correlations between both field strengths were found pre- and poststimulation (r = 0.955, and 0.936, respectively). CONCLUSION DW-EPI MR imaging allows monitoring of physiologic changes due to oral stimulation of parotid glands by using DW imaging with high correlation between 1.5T and 3T.
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Affiliation(s)
- C R Habermann
- Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Wilkinson P, Vos E, Konijn G, Kooijman H, Mosca G, Tonon L. Distillation Trays that Operate Beyond the Limits of Gravity by Using Centrifugal Separation. Chem Eng Res Des 2007. [DOI: 10.1205/cherd06103] [Citation(s) in RCA: 14] [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: 11/19/2022]
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Wedegärtner U, Popovych S, Yamamura J, Kooijman H, Adam G. In vivo T2 MR-Messungen zur Bestimmung der fetalen Blut-Sauerstoffsättigung während Hypoxie bei Schaf-Feten: eine Machbarkeitsstudie. ROFO-FORTSCHR RONTG 2007. [DOI: 10.1055/s-2007-976869] [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: 10/21/2022]
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Buskens E, Meijboom MJ, Kooijman H, Van Hout BA. The use of a surgical sealant (CoSeal) in cardiac and vascular reconstructive surgery: an economic analysis. J Cardiovasc Surg (Torino) 2006; 47:161-70. [PMID: 16572090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
AIM We designed a study to estimate the economic impact of CoSeal Surgical Sealant for the prevention of anastomotic bleeding in cardiac and vascular surgery. We also explored the potential economic value of CoSeal as a means of inhibiting the formation of pericardial tissue adhesions. METHODS A Delphi panel of 6 expert vascular and cardiac surgeons provided the assumptions and estimates needed to develop a decision analysis model to assess the impact of sealant on the costs associated with low- and high-risk forms of cardiac (valve replacement/reconstruction) and vascular (abdominal aortic aneurysm [AAA] repair, femoral bypass grafting) surgery. The primary outcome was incremental cost per patient. RESULTS For valve repair/replacement surgery, sealant was expected to confer cost-savings in high-risk but not low-risk procedures. Predicted cost savings for high-risk AAA repairs were substantial, but minimal in the overall AAA group. Cost-savings were predicted for sealant use in all femoral-popliteal ePTFE bypass grafts, but in high-risk femoral-femoral ePTFE bypass grafts only. CONCLUSIONS According to our decision analysis model, routine use of surgical sealant in select subgroups may confer considerable economic benefits to health service budgets. Future research should aim at testing this model in a real-world hospital setting. Assessment of the value of CoSeal in the prevention of postsurgical adhesions showed that expert surgeons see a need for effective prophylaxis. Further research into the clinical and economic benefit of this intervention is required.
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Affiliation(s)
- E Buskens
- Pharmerit BV, Rotterdam, The Netherlands.
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Allkemper T, Heindel W, Kooijman H, Ebert W, Tombach B. CMR 2005: 2.01: High-field MRA with iron oxide blood-pool contrast agents: field strength effects on vascular contrast enhancement in rabbits at 1.5 and 3.0 T. Contrast Media Mol Imaging 2006. [DOI: 10.1002/cmmi.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Stehling C, Bachmann R, Kooijman H, Nassenstein I, Vieth V, Heindel W, Fischbach R. Hochauflösende MR-Bildgebung des Kiefergelenks: Vergleich der Bildqualität bei 1,5 und 3 Tesla. ROFO-FORTSCHR RONTG 2006. [DOI: 10.1055/s-2006-941001] [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: 10/20/2022]
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Wedegärtner U, Kooijman H, Priest AN, Tchirikov M, Schröder H, Adam G. Quantitative T2*-Messungen der Oxygenierung im fetalen Gehirn während Hypoxie am 3T MRT: Vergleich mit fetalen arteriellen Blutgasanalysen. ROFO-FORTSCHR RONTG 2006. [DOI: 10.1055/s-2006-940685] [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: 10/20/2022]
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Nassenstein I, Krämer S, Kooijman H, Kugel H, Dittrich R, Stehling C, Niederstadt T, Heindel W, Bachmann R. Spezifische Zeichen der akuten Dissektion der supraaortalen Gefäße: Eine prospektiv vergleichende Studie bei 1,5 und 3,0 Tesla. ROFO-FORTSCHR RONTG 2006. [DOI: 10.1055/s-2006-940769] [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: 10/20/2022]
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Vieth V, Stehling C, Langer M, Krämer SC, Kooijman H, Kugel H, Heindel W, Bachmann R. Evaluierung eines hochauflösenden MR-Protokolls für die Untersuchung des Handgelenks bei 3.0 Tesla: Vergleich zum 1.5 Tesla Standardprotokoll. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867733] [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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Habermann CR, Gossrau P, Kooijman H, Graessner J, Cramer MC, Reitmeier F, Jaehne M, Adam G. Funktionelle Bildgebung der Glandula parotidea mittels diffusionsgewichteter echoplanarer MRT: Ein Vergleich zwischen 1.5T und 3.0T. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867882] [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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Bachmann R, Krämer SC, Kooijman H, Nassenstein I, Kugel H, Dittrich R, Niederstadt T, Heindel W. Hochaufgelöste Darstellung der Gefäßwand bei spontanen Dissektionen der Halsgefäße bei 3.0T: Eine prospektiv vergleichende Studie. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867462] [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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Habermann CR, Cramer MC, Graessner J, Kooijman H, Reitmeier F, Gossrau P, Jaehne M, Adam G. Functional Imaging of Parotid Glands: Diffusion-Weighted Echo-Planar MRI Before and After Stimulation using 1.5 T and 3 T. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-865266] [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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Priest AN, Ittrich H, Jahntz CL, Kölling M, Kooijman H, Weber C, Adam G. Investigation of Atherosclerotic Plaques with MRI using Ultra-Small Iron Oxide Particles at 3T. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-863982] [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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Habermann CR, Cramer MC, Graessner J, Kooijman H, Weiss F, Ußmüller J, Adam G. Fast and Ultra Fast MR-Sialography: Comparison of 1.5 T and 3 T. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-820830] [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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Walter C, Philippi G, Westerhausen R, Kooijman H, Hoffmannn HG, Busch HP. Hochauflösende 3D-MR-Angiographie (MRA) der Nierenarterien unter Verwendung der SENSE-Technik. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-827832] [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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Kooijman H. MRT – mit Sicherheit. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-828234] [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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Cramer M, Habermann CR, Reitmeier F, Graessner J, Kooijman H, Weiss F, Aldefeld D, Adam G. Schnelle und ultraschnelle MR-Sialographie: 1.5 T und 3 T im Vergleich. ROFO-FORTSCHR RONTG 2004. [DOI: 10.1055/s-2004-828114] [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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Walter C, Philippi G, Westerhausen R, Kooijman H, Hoffmann HG, Busch HP. [High resolution contrast-enhanced 3D MR-angiography of renal arteries using parallel imaging (SENSE)]. ROFO-FORTSCHR RONTG 2003; 175:1244-50. [PMID: 12964081 DOI: 10.1055/s-2003-41937] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To compare three dimensional contrast enhanced MR angiography with parallel imaging technique (sensitivity encoding) to standard MR angiography technique. MATERIAL AND METHODS CE-3D MRA of renal arteries was performed in 22 patients (23 examinations) on a 1.5 T MR- scanner (Gyroscan Intera, Philips, Netherlands). For contrast enhanced MRA a single dose of Gd-DTPA (0.1 mmol/kg b.w.) was administered. Group I: The following standard 3D gradient echo (GE) sequence was performed in 9 of the 22 patients: TR: 4.3 ms, TE: 1.5 ms, flip angle: 40, 40 slices, scan duration: 19 seconds. A spatial resolution of 1.96 x 1.76 x 3.0 mm (3) (1.76 x 1.76 x 1.5 mm (3) interpolated) was obtained. Group II: 14 examinations were acquired in 13 patients: TR, TE and flip angle were equal compared to the first protocol. The k-space lines were acquired with CENTRA (contrast-enhanced time robust angiography) and parallel imaging technique (SENSE). 60 slices were acquired, scan duration was 24 seconds. The spatial resolution of this sequence was 1.19 x 1.08 x 2.0 mm (3) (0,84 x 0,84 x 1,0 mm (3) interpolated). Original images and calculated maximum intensity projection (MIP) images were analysed by two radiologists. Image quality and the visibility of renal arteries were rated on a four-point scale. RESULTS In the first group the image quality was rated "good" in 8/9 patients. The renal arteries were detected in all cases and rated "good". The anterior and posterior segments were rated "good" in only 5/9 and the lobar arteries were detectable only in 3 of 9 cases. The interlobar arteries could not be seen in these patients. In the second group the image quality was rated excellent in 5 examinations and good in 9 of 14 examinations. The rating for the renal arteries was excellent in all examinations (14/14). The results of the anterior and posterior segment were as followed: excellent 5/14, good 7/14, insufficient 2/14; the lobar arteries: good 6/14, insufficient 6/14 and not detectable 2/14. Interlobar arteries could be seen in 7/14 examinations, but the quality was insufficient. In 7/14 the interlobar arteries could not be detected. CONCLUSION The use of parallel imaging technique improves image quality and the delineation of small vessels in renal MRA.
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Affiliation(s)
- C Walter
- Abteilung für Radiologie, Krankenhaus der Barmherzigen Brüder, Trier.
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Söntjens SH, Meijer JT, Kooijman H, Spek AL, van Genderen MH, Sijbesma RP, Meijer EW. A multiple hydrogen-bond scaffold based on dipyrimidin-2-ylamine. Org Lett 2001; 3:3887-9. [PMID: 11720561 DOI: 10.1021/ol016750a] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A multiple hydrogen-bond array based on dipyrimidin-2-ylamine is presented, which is easily accessible. The influence of a preorganizing intramolecular hydrogen bond, tautomeric equilibria, and steric effects on the association behavior were investigated. X-ray diffraction shows that the molecules feature an ADA (acceptor-donor-acceptor) array of hydrogen-bonding sites in the solid state. The array persists in solution, and (1)H NMR titrations show that molecules with sterically nondemanding DAD arrays are selectively bound. [structure: see text]
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Affiliation(s)
- S H Söntjens
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
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Nijsen JF, van Steenbergen MJ, Kooijman H, Talsma H, Kroon-Batenburg LM, van De Weert M, van Rijk PP, De Witte A, Van Schip AD, Hennink WE. Characterization of poly(L-lactic acid) microspheres loaded with holmium acetylacetonate. Biomaterials 2001; 22:3073-81. [PMID: 11575483 DOI: 10.1016/s0142-9612(01)00055-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Holmium-loaded PLLA microspheres are useful systems in radioembolization therapy of liver metastases because of their low density, biodegradability and favourable radiation characteristics. Neutron activated Ho-loaded microspheres showed a surprisingly low release of the relatively small holmium complex. In this paper factors responsible for this behaviour are investigated, in particular by the use of differential scanning calorimetry, scanning electron microscopy, infrared spectroscopy and X-ray diffraction. The holmium complex is soluble in PLLA up to 8% in films and 17% in microspheres. Interactions between carbonyl groups of PLLA, and the Ho-ion in the HoAcAc complex, explain very satisfactorily the high stability of holmium-loaded microspheres.
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Affiliation(s)
- J F Nijsen
- Department of Nuclear Medicine, University Medical Centre Utrecht, The Netherlands.
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34
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Boer DR, Kooijman H, Groen M, van der Louw J, Kelder J, Kroon J. Conformational comparison of five follicular fluid meiosis-activating sterol-related active and inactive compounds. Acta Crystallogr C 2001; 57:1177-81. [PMID: 11600777 DOI: 10.1107/s0108270101010010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2001] [Accepted: 06/18/2001] [Indexed: 11/10/2022] Open
Abstract
The crystal structures of five follicular fluid meiosis-activating sterol-related Delta(8,14)-sterol compounds are presented. These are 4,4-dimethyl-23-phenyl-24-nor-5alpha-chola-8,14-dien-3beta-ol, C(31)H(44)O, 4,4-dimethyl-22-phenyl-23,24-dinor-5alpha-chola-8,14-dien-3beta-ol, C(30)H(42)O, (20R)-4,4-dimethyl-22-oxa-5alpha,20-cholesta-8,14,24-trien-3beta-ol, C(28)H(44)O(2), 4,4-dimethyl-23-phenyl-22-oxa-24-nor-5alpha-chola-8,14-dien-3beta-ol-water (4/1), 4C(30)H(42)O(2).H(2)O, and 4,4-dimethyl-5alpha-cholesta-8,14-dien-3-one, C(29)H(46)O. Two of the derivatives are inactive and three are active as agonists. Preliminary structure-activity relationship studies showed that the positions of the double bonds in the skeleton and the structures of the side chains are important determinants for activity. The conformations of the skeletons were compared with double-bond isomers retrieved from the Cambridge Structural Database [Allen & Kennard (1993). Chem. Des. Autom. News, 8, 1, 31-37]; no significant differences were found. Thus, conformational changes induced by the double bonds are not discriminative with respect to the activity of the compounds. Comparisons of the side-chain conformations of active and inactive structures revealed that the crystal structures were not conclusive as far as correlation of conformation and activity of the side chains were concerned.
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Affiliation(s)
- D R Boer
- Bijvoet Center for Biomolecular Research, Department of Crystal and Structural Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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35
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Boer DR, Kooijman H, van der Louw J, Groen M, Kelder J, Kroon J. Relation between the molecular electrostatic potential and activity of some FF-MAS related sterol compounds. Bioorg Med Chem 2001; 9:2653-9. [PMID: 11557353 DOI: 10.1016/s0968-0896(01)00189-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Follicular Fluid-Meiosis Activating Sterol (FF-MAS) is a compound important for maturation of gametes in mammals. Therefore, it may serve as a lead compound for a novel method of contraception. We studied the Molecular Electrostatic Potential of a series of active and inactive analogues of FF-MAS. We find that double bond configurations required for activity result in a local negative electrostatic potential which is larger as well as more dense compared to those of inactive molecules. We therefore hypothesize that the interaction energy of the double bond system of the MAS compounds with its receptor substantially contributes to the overall interaction energy. This notion is supported by interaction studies of the electrostatic potential originating from the double bonds in crystal structures of cholesterol and four MAS-derived Delta(8,14) structures synthesized and crystallized by us. In addition, we were able to derive a pharmacophore model that relates the local average ESP and its distance to the 3beta-OH oxygen atom to the activity of the molecules.
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Affiliation(s)
- D R Boer
- Department of Crystal & Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
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36
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van Bommel KJ, de Jong MR, Metselaar GA, Verboom W, Huskens J, Hulst R, Kooijman H, Spek AL, Reinhoudt DN. Complexation and (templated) synthesis of rhenium complexes with cyclodextrins and cyclodextrin dimers in water. Chemistry 2001; 7:3603-15. [PMID: 11560332 DOI: 10.1002/1521-3765(20010817)7:16<3603::aid-chem3603>3.0.co;2-e] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Several small, lipophilic rhenium complexes form inclusion complexes with native beta-cyclodextrin (beta-CD) and beta-CD dimers. Association constants larger than 10(9)M(-1) were obtained using dimers. The use of beta-CD also enabled the synthesis of these rhenium complexes in water, in excellent yields, through complexation of the otherwise insoluble corresponding ligands. The influence of the reaction time and temperature on the configuration of the reaction products has been investigated in depth for one of these complexes. Using a beta-CD dimer, it proved possible to specifically template the formation of one configuration. The strength of the complexes of the rhenium complexes in cyclodextrin dimers may allow radiolabeling of biomolecules.
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Affiliation(s)
- K J van Bommel
- Laboratory of Supramolecular Chemistry and Technology, MESA+ Research Institute, University of Twente, Enschede, The Netherlands
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37
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Freund M, Adwan M, Kooijman H, Heiland S, Thomsen M, Hähnel S, Jensen K, Gerner HJ, Sartor K. [Measurement of CSF flow in the spinal canal using MRI with an optimized MRI protocol: experimental and clinical studies]. ROFO-FORTSCHR RONTG 2001; 173:306-14. [PMID: 11367838 DOI: 10.1055/s-2001-12463] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
PURPOSE Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. METHODS In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (mm2), and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 different power levels were measured at the stenosis and at a distance of 70 cm. RESULTS A total of 226 dynamic measurements have been performed--so far 76 in the first part (62 = 81.5% evaluable) and 150 in the second part--using the optimized sequence and optimal flow velocities. A flow-encoding sequence of 12 cm/s was found best in the CSC and one of 6 cm/s in the TSC and LSC. The maximum velocity in the CSC was 0.95 cm/s with the flow being directed caudal and 0.38 cm/s with the flow being directed cranial. In the TSC the values were 4.7 cm/s and 1.65 cm/s and in the LSC 0.96 cm/s and 0.59 cm/s. The highest velocities were found at the TSC, which has the smallest diameter compared to the CSC and LSC. In the 4 patients with PTS, the maximum velocities were between 0.09 cm/s and 0.97 cm/s with the flow being directed cranial and between 0.04 cm/s and 1.03 cm/s with the flow being directed caudal. The stroke volumina in the CSC were between 0.1 and 1.23 ml/s (mean: 0.48 ml/s) and 0.2 and 2.45 ml/s (mean: 0.66 ml/s) in the TSC and in the LSC 0.08 ml/s and 0.67 ml/s (mean: 0.29 ml/s). The results of the flow model studies showed an increase of velocity between 2.06 and 4.94 cm/s (mean: 3.31 cm/s) at the stenosis and 1.1 and 1.33 cm/s (mean: 1.23 cm/s) at a distance of 70 cm. CONCLUSION Quantitative measurement of the oscillating CSF flow in the entire spinal canal (SC) is possible using an optimized MRI protocol as well as to detect stenosis induced velocity changes. Due to the high interindividual variability in the data of spinal CSF dynamics, further studies are necessary to collect normal data. The detection of movement of CSF in a post-traumatic spinal cord lesion may alter the therapeutic management.
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Affiliation(s)
- M Freund
- Abteilung Neuroradiologie der Neurologischen Universitätsklinik, Universitätskliniken Heidelberg.
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Beyersdorff D, Schiemann T, Taupitz M, Kooijman H, Hamm B, Nicolas V. Sectional depiction of the pelvic floor by CT, MR imaging and sheet plastination: computer-aided correlation and 3D model. Eur Radiol 2001; 11:659-64. [PMID: 11354764 DOI: 10.1007/s003300000561] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The structures of the pelvic floor are clinically important but difficult to assess. To facilitate the understanding of the complicated pelvic floor anatomy on sectional images obtained by CT and MR imaging, and to make the representation more vivid, a computer-aided 3D model was created from a male and a female torso to develop a teaching tool. A male and a female cadaver torso were investigated by means of CT, MR imaging, and serial-section sheet plastination. A 3D reconstruction of the pelvic floor and adjacent structures was performed by fusion of CT and MR imaging data sets with sheet plastination sections. Corresponding sections from all three methods could be compared and visualized in their 3D context. Sheet plastination allows distinction of connective tissue, muscles, and pelvic organs down to a microscopic level. In combination with CT, MR imaging, and sheet plastination a 3D model of the pelvic floor offers a better understanding of the complex pelvic anatomy. This knowledge may be applied in the diagnostic imaging of urinary incontinence or prolapse and prior to prostate surgery.
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Affiliation(s)
- D Beyersdorff
- Department of Radiology, Charité, Humboldt University, Schumannstrasse 20/21, 10117 Berlin, Germany
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Wijsman GW, Iglesias GA, de Wolf WH, Beekman MC, Bickelhaupt F, Kooijman H, Spek AL. X-ray crystal structures and conformational analysis of bicyclo[5.3.1]undec-1(11)-enes: twisting versus pyradidalization in anti-bredt olefins. J Org Chem 2001; 66:1216-27. [PMID: 11312951 DOI: 10.1021/jo0013195] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of several 9,11,11-trihalo[5.3.1]propellanes and their 4-dimethylsila analogues is described. They solvolyze under formation of the corresponding isomeric 7,9,11- trihalobicyclo[5.3.l]undec-1(11)-enes which are "anti-Bredt" olefins with a strained trans double bond in a bridged eight-membered ring; in the presence of nucleophiles such as water or ethanol, the corresponding 7-hydroxy or 7-ethoxy derivatives, respectively, are obtained. On the basis of the X-ray crystal structures of four of these compounds (1a, 9a, 15, 17b), the effect of strain and of the substitution pattern on the degree of twisting and pyramidalization of the double bond is discussed.
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Affiliation(s)
- G W Wijsman
- Scheikundig Laboratorium, Vrije Universiteit, De Boelelaan 1083, NL-1081 HV, Amsterdam, The Netherlands
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Rohrschneider WK, Hoffend J, Becker K, Darge K, Wunsch R, Clorius JH, Kooijman H, Tröger J. [Static-dynamic MR urography. Comparison with excretory urography and scintigraphy in experimentally-induced urinary tract obstruction]. Radiologe 2001; 41:154-67. [PMID: 11253101 DOI: 10.1007/s001170050958] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction. METHODS Static-dynamic MRU--combination study with a respiratory-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furosemide--was obtained in comparison with 99mTc-MAG3 diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy piglets and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks). RESULTS MRU allowed complete depiction of the urinary tract in all controls, in operated piglets the stenosis was always correctly identified. Quality of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urinary excretion from whole-kidney renograms resulted in a highly significant agreement of MRU with DRS. CONCLUSION Static-dynamic MR urography allows excellent depiction of experimentally induced urinary tract obstruction, and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morphological correlation.
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Affiliation(s)
- W K Rohrschneider
- Pädiatrische Radiologie, Universität Heidelberg, Im Neuenheimer Feld 153, 69120 Heidelberg.
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Abstract
Symmetrical 2,5-bis(2-aminophenyl)pyrazines have been synthesized by application of the Stille coupling strategy. These cotrimers feature three important properties, namely strong intramolecular hydrogen bonding, push-pull character, and high electron affinity. The presence of intramolecular hydrogen bonds has been confirmed by 1H NMR, IR spectroscopy, and single-crystal X-ray diffraction. The hydrogen bond strength can be increased by substituting the amino groups with stronger electron-withdrawing functionalities. Despite the anticipated enhanced pi-conjugation through planarization, a hypsochromic shift was observed in the UV/Vis spectra, explained by a decrease in push-pull character. The electron affinity of the cotrimers was deduced from the first reduction potentials measured by cyclic voltammetry and is related to the electron-withdrawing character of the amino substituents. The results obtained have been compared with those of the corresponding 4-aminophenyl analogues and show that intramolecular hydrogen bonds can be used to design polymers with enhanced pi conjugation as well as a high electron affinity.
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Affiliation(s)
- K Pieterse
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, The Netherlands
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Abstract
The calix[4]arene platform was used for the syntheses of novel rhenium(V) complexes, that may have potential applications as radiopharmaceuticals. The reaction of ReO(PPh3)2Cl3 with tetradentate N2O2-calix[4]arene ligand 8 in ethanol gave the novel mixed-ligand rhenium complex 9 with the structure ReO(N2O2-calix)OEt. The configuration was elucidated by using a number of 1H NMR techniques. In 9, the ethoxy ligand could be easily and quantitatively exchanged for another monodentate ligand to give complex 12. Tetradentate N2S2-calix[4]arene ligand 15 formed the rhenium complex 16 either via reaction with ReO(PPh3)2Cl3 in an organic solvent or by reaction with rhenium gluconate in an aqueous solution. Complex 16 showed good stability in phosphate-buffered saline solution (37 degrees C, 5 d). The crystal structures of a mono- and a bimetallic complex were determined. The bimetallic N2O2-calixarene complex dimer 11 crystallized in the monoclinic space group C2/c, with a = 38.963(5) A, b = 23.140(6) A, c = 27.382(6) A, beta = 128.456(10) degrees, V = 19,333(7) A3, Z = 8, and final R = 0.0519. The monometallic N2S2 model complex 17 crystallized in the monoclinic space group Cc, with a = 15.715(2) A, b = 12.045(2) A, c = 20.022(3) A, beta = 94.863(12) degrees, V = 3776.3(10) A3, Z = 4, and final R = 0.0342.
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Affiliation(s)
- K J van Bommel
- Laboratory of Supramolecular Chemistry and Technology, MESA+ Research Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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Hagen H, Bezemer C, Boersma J, Kooijman H, Lutz M, Spek AL, van Koten G. Vanadium(IV) and -(V) complexes with O,N-chelating aminophenolate and pyridylalkoxide ligands. Inorg Chem 2000; 39:3970-7. [PMID: 11198849 DOI: 10.1021/ic991415s] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two different monoanionic O,N-chelating ligand systems, i.e., [OC6H2(CH2NMe2)-2-Me2-4,6]- (1) and [OCMe2([2]-Py)]- (2), have been applied in the synthesis of vanadium(V) complexes. The tertiary amine functionality in 1 caused reduction of the vanadium nucleus to the 4+ oxidation state with either [VOCl3], [V(=NR)Cl3], or [V(=NR)(NEt2)3] (R = Ph, (3a, 5a), R = p-Tol (3b, 5b)), and applying 1 as a reducing agent resulted in the synthesis of the vanadium(IV) complexes [VO(OC6H2(CH2NMe2)-2-Me2-4,6)2] (4) and [V(=NPh)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (6). In the case of [V(=N-p-Tol)(NEt2)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (7b), the reduction was sufficiently slow to allow its characterization by 1H NMR and variable-temperature studies showed it to be a five-coordinate species in solution. Although the reaction of 1 with [V(=N-p-Tol)(O-i-Pr)3] (9b) did not result in reduction of the vanadium nucleus, vanadium(V) compounds could not be isolated. Mixtures of the vanadium(V) (mono)phenolate, [V(=N-p-Tol)(O-i-Pr)2(OC6H2(CH2NMe2)-2-Me2-4,6)] (10), and the vanadium(V) (bis)phenolate, [V(=N-p-Tol)(O-i-Pr)(OC6H2(CH2NMe2)-2-Me2-4,6)2] (11), were obtained. With the pyridylalkoxide 2, no reduction was observed and the vanadium(V) compounds [VOCl2(OCMe2([2]-Py))] (12) and [V(=N-p-Tol)Cl2(OCMe2([2]-Py)] (13) were obtained. 51V NMR showed 7b and 12 to be five-coordinate in solution, whereas for 10, 11, and 13 a coordination number of 6 was found. Compounds 12 and 13 showed decreased activity compared to their nonchelated vanadium(V) analogues when applied as catalysts in ethene polymerization. Two polymorphic forms with a difference in the V-N-C angle of 12.5 degrees have been found for 6. Crystal data: 6.Et2O, triclinic, P1, a = 11.1557(6) A, b = 12.5744(12) A, c = 13.1051(14) A, alpha = 64.244(8) degrees, beta = 70.472(7) degrees, gamma = 87.950(6) degrees, V = 1547(3) A3, Z = 2; 6.C6H6, triclinic, P1, a = 8.6034(3) A, b = 13.3614(4) A, c = 15.1044(5) A, alpha = 98.182(3) degrees, beta = 105.618(2) degrees, gamma = 107.130(2) degrees, V = 1551.00(10) A3, Z = 2; 12, orthorhombic, Pbca, a = 11.8576(12) A, b = 12.6710(13) A, c = 14.722(2) A, V = 2211.9(4) A3, Z = 8.
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Affiliation(s)
- H Hagen
- Debye Institute, Department of Metal-Mediated Synthesis, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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Rohrschneider WK, Hoffend J, Becker K, Clorius JH, Darge K, Kooijman H, Tröger J. Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. I. Evaluation of the normal status in an animal model. Pediatr Radiol 2000; 30:511-22. [PMID: 10993535 DOI: 10.1007/s002470000270] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE A new approach, combined static-dynamic MR urography is evaluated to determine its potential utility for the functional-morphological diagnosis of paediatric urinary tract obstruction. In this initial investigation we sought to evaluate the procedure by imaging the urinary tract of piglets. MATERIALS AND METHODS Twenty-nine healthy piglets were studied with MR urography (MRU), 99mTc-MAG3 diuretic renal scintigraphy (DRS), ultrasound (US) and excretory urography (EU). The functional and morphological findings were compared. For MRU we combined a respiration-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA injection. RESULTS MRU depicted the complete urinary tract with superior image quality compared to EU. Calculation of time-intensity curves from the dynamic sequence permitted determination of single kidney function from parenchymal ROIs and urinary excretion using the whole kidney ROI. MRU and DRS showed significant agreement in the assessment of both single kidney function and urinary excretion. Disturbances of urinary drainage were generally caused by an overfilled bladder. CONCLUSIONS Combined static-dynamic MRU is well suited for the depiction of the complete urinary tract and for the determination of individual kidney function and urinary excretion in the piglet.
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Rohrschneider WK, Becker K, Hoffend J, Clorius JH, Darge K, Kooijman H, Tröger J. Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. II. Findings in experimentally induced ureteric stenosis. Pediatr Radiol 2000; 30:523-32. [PMID: 10993536 DOI: 10.1007/s002470000273] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet. MATERIALS AND METHODS In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration. RESULTS MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86% and slightly discordant results in 12%. CONCLUSIONS Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out--it does not require radiation and it permits functional-morphological correlation.
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Velders AH, Kooijman H, Spek AL, Haasnoot JG, de Vos D, Reedijk J. Strong differences in the in vitro cytotoxicity of three isomeric dichlorobis(2-phenylazopyridine)ruthenium(II) complexes. Inorg Chem 2000; 39:2966-7. [PMID: 11196889 DOI: 10.1021/ic000167t] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A H Velders
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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Abstract
The course of the hydrogenation of [5]- and [6]metacyclophane (1b and 1c) and their thermochemistry is described. Both compounds are hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstable olefins which correlates nicely with its reluctance to undergo hydrogenation. By combining experimental hydrogenation enthalpies and DFT calculations, SE of 187 and 121 kJmol(-1) were derived for 1b and 1c.
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van Koningsbruggen PJ, Garcia Y, Kahn O, Fournès L, Kooijman H, Spek AL, Haasnoot JG, Moscovici J, Provost K, Michalowicz A, Renz F, Gütlich P. Synthesis, crystal structure, EXAFS, and magnetic properties of catena [mu-tris(1,2-bis(tetrazol-1-yl)propane-N1,N1')iron(II)] bis(perchlorate). First crystal structure of an iron(II) spin-crossover chain compound. Inorg Chem 2000; 39:1891-900. [PMID: 11428109 DOI: 10.1021/ic991118n] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[Fe(btzp)3](ClO4)2 (btzp = 1,2-bis(tetrazol-1-yl)propane) represents the first structurally characterized Fe(II) linear chain compound exhibiting thermal spin crossover. It shows a very gradual spin transition (T1/2 = 130 K) which has been followed by magnetic susceptibility measurements and 57Fe Mössbauer spectroscopy. The structure has been solved at 200 and 100 K by single-crystal X-ray analysis. It crystallizes in the trigonal space group P3c1 with Z = 2 Fe(II) units at both temperatures. The molecular structure consists of chains running along the c axis in which the Fe(II) ions are linked by three N4,N4' coordinating bis(tetrazole) ligands. The main difference between the two forms appears to be in the Fe-N bond lengths, which are 2.164(4) A at 200 K and 2.038(4) A at 100 K. The Fe-Fe separations are 7.422(1) A at 200 K and 7.273(1) A at 100 K. The EXAFS results are consistent with the crystal structure. In both spin states, the FeN6 octahedron is almost regular within the EXAFS resolution. The Fe-N distance is found as 2.16(2) A at 300 K and 2.00(2) A at 40 K. The absence of the "7 A peak" in the EXAFS spectra of [Fe(btzp)3](ClO4)2, in contrast with what has been observed for the [Fe(4-R-1,2,4-triazole)3]-(anion)2 chain compounds, confirms that this peak can be used as the signature of a metal alignment only when it involves a strongly enhanced multiple scattering M-M-M path, with M-M spacing less than 4 A. Irradiation with green light at 5 K has led to the population of the metastable high-spin state for the iron(II) ion. The nature of the spin-crossover behavior has been discussed on the basis of the structural features.
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Affiliation(s)
- P J van Koningsbruggen
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg University, Staudingerweg 9, D-55099 Mainz, Germany
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Kooijman H, Spek AL, Kleijn H, van Maanen HL, Jastrzebski JT, van Koten G. (3R,4S)-3-phenyl-1-[(R)-1-phenylethyl]-4-[(R)-1-phenylethyliminomethyl] azetidin-2-one. Acta Crystallogr C 2000; 56 ( Pt 4):481-3. [PMID: 10815219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Affiliation(s)
- H Kooijman
- Bijvoet Center for Biomolecular Research, Department of Crystal and Structural Chemistry, Utrecht University, The Netherlands.
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Bouma B, Kooijman H, Kroon J, Grech E, Brzezinski B. 1,8-Bis(dimethylaminomethyl)naphthalene bis(squaric acid) dihydrate. Acta Crystallogr C 1999. [DOI: 10.1107/s0108270199009853] [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: 11/10/2022] Open
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