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Fischer J, Bouhana K, Chicarelli M, Dahlke J, Fell B, Fulton J, Guarnieri A, Haygood L, Jalluri R, Johnson A, McLean B, Max M, Rieger R, Robinson J, Rodriguez M, Sullivan F, Wang Y, Winski S, Zhou Y. In Vivo Pre-clinical characterization of a Novel Series of FGFR2 Selective Inhibitors with Potency Against Clinically Relevant Mutations. Eur J Cancer 2022. [DOI: 10.1016/s0959-8049(22)01016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Niedbalski PJ, Cochran AS, Freeman MS, Guo J, Fugate EM, Davis CB, Dahlke J, Quirk JD, Varisco BM, Woods JC, Cleveland ZI. Validating in vivo hyperpolarized 129 Xe diffusion MRI and diffusion morphometry in the mouse lung. Magn Reson Med 2021; 85:2160-2173. [PMID: 33017076 PMCID: PMC8544163 DOI: 10.1002/mrm.28539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/27/2020] [Accepted: 09/14/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE Diffusion and lung morphometry imaging using hyperpolarized gases are promising tools to quantify pulmonary microstructure noninvasively in humans and in animal models. These techniques assume the motion encoded is exclusively diffusive gas displacement, but the impact of cardiac motion on measurements has never been explored. Furthermore, although diffusion morphometry has been validated against histology in humans and mice using 3 He, it has never been validated in mice for 129 Xe. Here, we examine the effect of cardiac motion on diffusion imaging and validate 129 Xe diffusion morphometry in mice. THEORY AND METHODS Mice were imaged using gradient-echo-based diffusion imaging, and apparent diffusion-coefficient (ADC) maps were generated with and without cardiac gating. Diffusion-weighted images were fit to a previously developed theoretical model using Bayesian probability theory, producing morphometric parameters that were compared with conventional histology. RESULTS Cardiac gating had no significant impact on ADC measurements (dual-gating: ADC = 0.020 cm2 /s, single-gating: ADC = 0.020 cm2 /s; P = .38). Diffusion-morphometry-generated maps of ADC (mean, 0.0165 ± 0.0001 cm2 /s) and acinar dimensions (alveolar sleeve depth [h] = 44 µm, acinar duct radii [R] = 99 µm, mean linear intercept [Lm ] = 74 µm) that agreed well with conventional histology (h = 45 µm, R = 108 µm, Lm = 63 µm). CONCLUSION Cardiac motion has negligible impact on 129 Xe ADC measurements in mice, arguing its impact will be similarly minimal in humans, where relative cardiac motion is reduced. Hyperpolarized 129 Xe diffusion morphometry accurately and noninvasively maps the dimensions of lung microstructure, suggesting it can quantify the pulmonary microstructure in mouse models of lung disease.
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Affiliation(s)
- Peter J. Niedbalski
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Alexander S. Cochran
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Matthew S. Freeman
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Elizabeth M. Fugate
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Cory B. Davis
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Physics, West Texas A&M University, Canyon, TX
| | - Jerry Dahlke
- Department of Radiology, Duke University School of Medicine, Durham, NC
| | - James D. Quirk
- Department of Radiology, Washington University, St. Louis, MO
| | - Brian M. Varisco
- Division of Critical Care Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Jason C. Woods
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Radiology, Washington University, St. Louis, MO
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
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Virgincar RS, Dahlke J, Robertson SH, Morand N, Qi Y, Degan S, Driehuys B, Nouls JC. A portable ventilator with integrated physiologic monitoring for hyperpolarized 129Xe MRI in rodents. J Magn Reson 2018; 295:63-71. [PMID: 30125865 PMCID: PMC6719309 DOI: 10.1016/j.jmr.2018.07.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/13/2018] [Accepted: 07/21/2018] [Indexed: 05/09/2023]
Abstract
Hyperpolarized (HP) 129Xe MRI is emerging as a powerful, non-invasive method to image lung function and is beginning to find clinical application across a range of conditions. As clinical implementation progresses, it becomes important to translate back to well-defined animal models, where novel disease signatures can be characterized longitudinally and validated against histology. To date, preclinical 129Xe MRI has been limited to only a few sites worldwide with 2D imaging that is not generally sufficient to fully capture the heterogeneity of lung disease. To address these limitations and facilitate broader dissemination, we report on a compact and portable HP gas ventilator that integrates all the gas-delivery and physiologic monitoring capabilities required for high-resolution 3D hyperpolarized 129Xe imaging. This ventilator is MR- and HP-gas compatible, driven by inexpensive microcontrollers and open source code, and allows for precise control of the tidal volume and breathing cycle in perorally intubated mice and rats. We use the system to demonstrate data acquisition over multiple breath-holds, during which lung motion is suspended to enable high-resolution 3D imaging of gas-phase and dissolved-phase 129Xe in the lungs. We demonstrate the portability and versatility of the ventilator by imaging a mouse model of lung cancer longitudinally at 2 Tesla, and a healthy rat at 7 Tesla. We also report the detection of subtle spectroscopic fluctuations in phase with the heart rate, superimposed onto larger variations stemming from the respiratory cycle. This ventilator was developed to facilitate duplication and gain broad adoption to accelerate preclinical 129Xe MRI research.
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Affiliation(s)
| | - Jerry Dahlke
- Radiology, Duke University Medical Center, Durham, NC, USA
| | | | | | - Yi Qi
- Radiology, Duke University Medical Center, Durham, NC, USA
| | - Simone Degan
- Radiology, Duke University Medical Center, Durham, NC, USA
| | - Bastiaan Driehuys
- Biomedical Engineering, Duke University, Durham, NC, USA; Radiology, Duke University Medical Center, Durham, NC, USA; Medical Physics Graduate Program, Duke University, Durham, NC, USA
| | - John C Nouls
- Radiology, Duke University Medical Center, Durham, NC, USA.
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Dahlke J, Tepper R, Geitner R, Zechel S, Vitz J, Kampes R, Popp J, Hager MD, Schubert US. A healing ionomer crosslinked by a bis-bidentate halogen bond linker: a route to hard and healable coatings. Polym Chem 2018. [DOI: 10.1039/c8py00149a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bis-bidentate halogen bond linker was introduced into a fully organic, phosphate based ionomer, yielding a crosslinked network with healing abilities and improved mechanical properties.
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Affiliation(s)
- J. Dahlke
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - R. Tepper
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - R. Geitner
- Institute for Physical Chemistry and Abbe Center of Photonics (ACP)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Leibniz Institute for Photonic Technology (IPHT) Jena
| | - S. Zechel
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - J. Vitz
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - R. Kampes
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - J. Popp
- Jena Center for Soft Matter (JCSM)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Institute for Physical Chemistry and Abbe Center of Photonics (ACP)
| | - M. D. Hager
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - U. S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
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Stang A, Keles H, Hentschke S, von Seydewitz CU, Dahlke J, Habermann C, Wessling J. Incidentally detected splenic lesions in ultrasound: does contrast-enhanced ultrasonography improve the differentiation of benign hemangioma/hamartoma from malignant lesions? Ultraschall Med 2011; 32:582-592. [PMID: 22161555 DOI: 10.1055/s-0031-1282034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE The aim of the study was to identify and validate enhancing features for differentiating benign vascular neoplasms of the hemangioma/hamartoma type from malignant splenic lesions on contrast-enhanced ultrasonography (CEUS). MATERIALS AND METHODS 136 splenic lesions (58 benign vascular neoplasms, 78 malignant) in 136 patients underwent baseline US and pulse-inversion CEUS after sulfur hexafluoride-filled microbubble injection. Two on-site readers assessed lesion enhancement features during arterial and parenchymal phase in consensus. Best predicting CEUS features for lesion diagnosis were identified through univariate and multivariate analyses. Two blinded off-site readers independently issued a confidence rating for lesion diagnosis in baseline US and CEUS using extracted diagnostic CEUS features. Diagnostic performance, receiver operating curves (Az-value), and interreader agreement were calculated. The reference standards were histopathology or CT and/or MR imaging with clinical follow-up. RESULTS Multivariate analysis outlined arterial hyperenhancement or isoenhancement to be an independent CEUS predictor of benign vascular neoplasms (odds ratio, 3.558; p < 0.0017). Within the subgroup of isoechoic or hypoechoic lesions, arterial hyperenhancement was virtually diagnostic for benign vascular neoplasm (odds ratio, 21.333; p < 0.001). The diagnostic accuracy and confidence (Az-value) of the two readers was 63.2 % and 70.6 % (0.785 and 0.818) for baseline US, which improved significantly to 87.5 % and 88.2 % (0.915 and 0.908) for CEUS (p < 0.001). Interreader agreement also increased with CEUS (қ = 0.88) compared to baseline US (қ = 0.52). CONCLUSION Sulfur hexafluoride-enhanced CEUS improves differentiation between benign vascular and malignant splenic tumors and may be especially useful in clinical scenarios in which the incidental hypoechoic splenic lesion is unclear on conventional US.
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Affiliation(s)
- A Stang
- Department of Hematology, Oncology, and Palliative Care, Asklepios Hospital Barmbek, Hamburg, Germany.
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Saager B, Rohde H, Timmerbeil BS, Franke G, Pothmann W, Dahlke J, Scherpe S, Sobottka I, Heisig P, Horstkotte MA. Molecular characterisation of linezolid resistance in two vancomycin-resistant (VanB) Enterococcus faecium isolates using Pyrosequencing™. Eur J Clin Microbiol Infect Dis 2008; 27:873-8. [DOI: 10.1007/s10096-008-0514-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 03/25/2008] [Indexed: 11/29/2022]
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Dahlke J, Sobottka I, Rhode H, Franke G, Zabelina T, Lellek H, Muth A, Wolschke C, Zander A, Kröger N. P720 Successful treatment of a linezolid-and vancomycin-resistant Enterococcus faecium sepsis with daptomycin plus doxycycline in an allogenic stem cell transplant recipient. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)70561-7] [Citation(s) in RCA: 1] [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: 11/25/2022]
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Kröger N, Shimoni A, Zabelina T, Schieder H, Panse J, Ayuk F, Wolschke C, Renges H, Dahlke J, Atanackovic D, Nagler A, Zander A. Reduced-toxicity conditioning with treosulfan, fludarabine and ATG as preparative regimen for allogeneic stem cell transplantation (alloSCT) in elderly patients with secondary acute myeloid leukemia (sAML) or myelodysplastic syndrome (MDS). Bone Marrow Transplant 2006; 37:339-44. [PMID: 16415898 DOI: 10.1038/sj.bmt.1705259] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [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: 11/09/2022]
Abstract
We investigated a dose-reduced conditioning regimen consisting of treosulfan and fludarabine followed by allogeneic stem cell transplantation (SCT) in 26 patients with secondary AML or MDS. Twenty patients were transplanted from matched or mismatched unrelated donors and six from HLA-identical sibling donors. The median age of the patients was 60 years (range, 44-70). None of the patients was eligible for a standard myeloablative preparative regimen. No graft-failure was observed, and leukocyte and platelet engraftment were observed after a median of 16 and 17 days, respectively. Acute graft-versus-host disease (GvHD) grade II-IV was seen in 23% and severe grade III GvHD in 12% of the patients. No patients experienced grade IV acute GvHD. Chronic GvHD was noted in 36% of the patients, which was extensive disease in 18%. The 2-year cumulative incidence of relapse was 21%. The relapse rate was higher in patients beyond CR1 or with intermediate two or high risk MDS (P = 0.02). The treatment-related mortality at day 100 was 28%. The 2-year estimated overall and disease-free survival was 36-34%, respectively. No difference in survival was seen between unrelated and related SCT.
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Affiliation(s)
- N Kröger
- Department of Bone Marrow Transplantation, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
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Dahlke J, Kröger N, Zabelina T, Ayuk F, Fehse N, Wolschke C, Waschke O, Schieder H, Renges H, Krüger W, Kruell A, Hinke A, Erttmann R, Kabisch H, Zander AR. Comparable results in patients with acute lymphoblastic leukemia after related and unrelated stem cell transplantation. Bone Marrow Transplant 2005; 37:155-63. [PMID: 16284608 DOI: 10.1038/sj.bmt.1705221] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [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: 11/09/2022]
Abstract
We report the results of 84 patients with ALL after related (n = 46) or unrelated (n = 38) allogeneic SCT. Mean recipient age was 23 years (range: 1-60) and median follow-up was 18 months (range: 1-133). Forty-three patients were transplanted in CR1; 25 in CR2 or CR3; four were primary refractory; four in PR; eight in relapse. The conditioning regimen consisted of TBI/VP16/CY (n = 76), TBI/VP16 (n = 2), TBI/CY (n = 2), Bu/VP16/CY (n = 4). The OS at 3 years was 45% (44% unrelated, 46% related). Univariate analysis showed a significantly better OS for patients <18 years (P=0.03), mismatched sex-combination (P = 0.03), both with a stronger effect on increasing OS after unrelated SCT. Factors decreasing TRM were patient age <18 years (P = 0.004), patient CMV-seronegativity (P = 0.014), female recipient (P = 0.04). There was no significant difference in TRM and the relapse rate was similar in both donor type groups. Multivariate analysis showed that factors for increased OS which remained significant were mismatched sex-combination (RR: 0.70,95% CI: 0.51-0.93, P = 0.015), patient age < 18 years (RR: 0.66, 95% CI: 0.47-0.93, P = 0.016). A decreased TRM was found for female patients (RR: 0.56, 95% CI: 0.33-0.98, P=0.042), negative CMV status of the patient (RR: 0.57, 95% CI: 0.36-0.90, P = 0.015). Unrelated stem cell transplantation for high-risk ALL patients with no HLA-compatible family donor is justifiable.
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Affiliation(s)
- J Dahlke
- Department of Bone Marrow Transplantation, University Hospital Hamburg-Eppendorf, Hamburg, Germany
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Graf Finckenstein F, Zabelina T, Dürken M, Dahlke J, Kröger N, Krüger W, Janka-Schaub G, Erttmann R, Zander AR, Kabisch H. [Unrelated donor stem cell transplantation in children: low toxicity using a GvHD-prophylaxis regimen with CSA, MTX, metronidazole,iv-immunoglobulin and ATG]. Klin Padiatr 2002; 214:206-11. [PMID: 12165903 DOI: 10.1055/s-2002-33177] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Unrelated donor (UD) hematopoietic stem cell transplantation (HSCT) is accepted as a therapy for leukaemic diseases and varying inborn diseases if a suitable related donor cannot be found. The goal of immunosuppressive therapy with UD-HSCT is an effective prevention of graft-versus-host-disease (GvHD) on one hand. On the other hand an optimal balance with immunocompetence of the transplanted bone marrow is desirable in order to prevent graft failure, infection and, in the case of leukaemic diseases, potentially control the underlying disease. PATIENTS AND METHODS Between 1992 and 2000 49 patients aged 11 months to 16.7 years received an UD-HSCT in Hamburg. Underlying diseases were leukaemia or MDS in 35, of these ALL in 21, hemophagocytic lymphohistiocytosis (HLH) in 9, immunodeficiency or inborn error of metabolism in 5 patients. GvHD-prophylaxis consisted of a combination of Cyclosporin A (CSA), methotrexate (MTX), metronidazole, IgM-enriched iv-immunoglobulin (ivIg) (Pentaglobin(R)) or ivIgG and anti-thymocyte-globulin (ATG). Within the same time span 10 patients with ALL received a matched related donor HSCT (MRD-HSCT). GvHD-prophylaxis in these patients was done without ATG in 8 of 10 cases. UD-HSCT were analyzed for survival, relapse and toxicity. Probability of survival of the patients with ALL after UD-HSCT was compared with results of MRD-HSCT in children with ALL. RESULTS The Kaplan-Meier estimates of three year overall-survival (OS) were 74 % for all patients. Probability of disease-free survival (DFS) at three years was 62 % for leukaemia/MDS-patients and 100 % for the HLH-patients. Acute GvHD (aGvHD) grades II or III occurred in 51 % of patients. Chronic GvHD (cGvHD) occurred in 22 % of patients. There were 5 cases of treatment-related mortality (TRM). Probability of DFS for patients with ALL at three years was 65 % after UD-HSCT and 30 % in the patients after MRD-HSCT. CONCLUSIONS UD-HSCT in children is an effective and safe therapy. A GvHD-prophylaxis regimen combining the standard immunosuppressive agents CSA and MTX with ivIg, metronidazole and serotherapy using ATG may result in a low incidence of severe GvHD-complications and low TRM rate without increase in relapse rates.
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Spritzer CE, Keogan MT, DeLong DM, Dahlke J, MacFall JR. Optimizing fast spin echo acquisitions for hepatic imaging in normal subjects. J Magn Reson Imaging 1996; 6:128-35. [PMID: 8851417 DOI: 10.1002/jmri.1880060124] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 02/02/2023] Open
Abstract
The purpose of this study was to determine which implementations of a T2-weighted fast spin-echo sequence of the liver resulted in observer preference in normal subjects. Five volunteers were scanned with a series of fast spin-echo sequences modified to allow for flow compensation, respiratory triggering (RT), ECG triggering, randomized phase encoding (RPE), breath-holding, and echo train length (ETL). Images were compared with conventional 2500/40/80 msec spin-echo images using flow compensation and spatial presaturation by two observers blinded to the specific sequence parameters. All FSE sequences were completed in less than the 12 minutes necessary to perform a conventional spin-echo sequence. The most preferred fast spin-echo sequence employed flow compensation, RT, and used an 8 ETL. Analysis of image preference, signal to noise, and contrast to noise showed that RT was the single most important variable in determining each image response (P < .01, P < .02, P < .01, respectively). There was some evidence that images obtained with an 8 ETL were preferred over those using a 16 ETL (P = .07). No other variables approached statistical significance although one reader preferred images with flow compensation in the frequency direction to those either not flow compensated or flow compensated in the slice direction. Respiratory triggered fast spin-echo images combined with flow compensation in the frequency direction and using ETL = 8 can provide image quality equal to conventional spin-echo sequences with significant time savings.
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Affiliation(s)
- C E Spritzer
- Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
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Abstract
Breathing motion severely degrades the quality of magnetic resonance images (MRI) of the thorax and upper abdomen and interferes with the acquisition of quantitative data. To minimize these motion effects, we built an MRI compatible ventilator for use in animal studies. Solid state circuitry is used for controlling ventilation parameters. The ventilator can be triggered internally at frequencies of 0.1 to 30 Hz or it can be triggered externally such as by the MRI pulse sequence. When triggered by the scanner, ventilation is synchronized to occur between image data acquisitions. Thus, image data are obtained when there is no breathing motion and at a minimum lung volume when hydrogen density is maximum. Since the ventilator can be adjusted to operate at virtually any frequency from conventional to high frequency, ventilation can be synchronized to all commonly used repetition times (100 ms to 2000 ms or more; 600 to 30 breaths/min). Scan synchronous ventilation eliminates breathing motion artifacts from most imaging sequences (single and multiple spin echo and inversion recovery). Best image quality is obtained when scan synchronous ventilation is combined with cardiac gating. These methods are also useful for quantitative research studies of thoracic and abdominal organs.
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