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Wang PN, Velikina JV, Strigel RM, Henze Bancroft LC, Samsonov AA, Cashen TA, Wang K, Kelcz F, Johnson KM, Korosec FR, Ersoz A, Holmes JH. Comparison of data-driven and general temporal constraints on compressed sensing for breast DCE MRI. Magn Reson Med 2021; 85:3071-3084. [PMID: 33306217 DOI: 10.1002/mrm.28628] [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: 06/03/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE Current breast DCE-MRI strategies provide high sensitivity for cancer detection but are known to be insufficient in fully capturing rapidly changing contrast kinetics at high spatial resolution across both breasts. Advanced acquisition and reconstruction strategies aim to improve spatial and temporal resolution and increase specificity for disease characterization. In this work, we evaluate the spatial and temporal fidelity of a modified data-driven low-rank-based model (known as MOCCO, model consistency condition) compressed-sensing (CS) reconstruction compared to CS with temporal total variation with radial acquisition for high spatial-temporal breast DCE MRI. METHODS Reconstruction performance was characterized using numerical simulations of a golden-angle stack-of-stars breast DCE-MRI acquisition at 5-second temporal resolution. Specifically, MOCCO was compared with CS total variation and conventional SENSE reconstructions. The temporal model for MOCCO was prelearned over the source data, whereas CS total variation was performed using a first-order temporal gradient sparsity transform. RESULTS The MOCCO reconstruction was able to capture rapid lesion kinetics while providing high image quality across a range of optimal regularization values. It also recovered kinetics in small lesions (1.5 mm) in line-profile analysis and error images, whereas g-factor maps showed relatively low and constant values with no significant artifacts. The CS-TV method demonstrated either recovery of high spatial resolution with reduced temporal accuracy using large regularization values, or recovery of rapid lesion kinetics with reduced image quality using low regularization values. CONCLUSION Simulations demonstrated that MOCCO with radial acquisition provides a robust imaging technique for improving temporal fidelity, while maintaining high spatial resolution and image quality in the setting of bilateral breast DCE MRI.
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Affiliation(s)
- Ping N Wang
- Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Julia V Velikina
- Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Roberta M Strigel
- Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Leah C Henze Bancroft
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Alexey A Samsonov
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Ty A Cashen
- Global MR Applications & Workflow, GE Healthcare, Madison, Wisconsin, USA
| | - Kang Wang
- Global MR Applications & Workflow, GE Healthcare, Madison, Wisconsin, USA
| | - Frederick Kelcz
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Frank R Korosec
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Ali Ersoz
- MR Engineering, GE Healthcare, Waukesha, Wisconsin, USA
| | - James H Holmes
- Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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Ichikawa S, Motosugi U, Kromrey ML, Tamada D, Wakayama T, Wang K, Cashen TA, Ersoz A, Onishi H. Utility of Stack-of-stars Acquisition for Hepatobiliary Phase Imaging without Breath-holding. Magn Reson Med Sci 2019; 19:99-107. [PMID: 31061270 PMCID: PMC7232028 DOI: 10.2463/mrms.mp.2019-0030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose: Post-contrast liver magnetic resonance imaging is typically performed with breath-hold 3D gradient echo sequences. However, breath-holding for >10 s is difficult for some patients. In this study, we compared the quality of hepatobiliary phase (HBP) imaging without breath-holding using the prototype pulse sequences stack-of-stars liver acquisition with volume acceleration (LAVA) (LAVA Star) with or without navigator echoes (LAVA Starnavi+ and LAVA Starnavi−) and Cartesian LAVA with navigator echoes (Cartesian LAVAnavi+). Methods: Seventy-two patients were included in this single-center, retrospective, cross-sectional study. HBP imaging using the three LAVA sequences (Cartesian LAVAnavi+, LAVA Starnavi−, and LAVA Starnavi+) without breath-holding was performed for all patients using a 3T magnetic resonance system. Two independent radiologists qualitatively analyzed (overall image quality, liver edge sharpness, hepatic vein clarity, streak artifacts, and respiratory motion/pulsation artifacts) HBP images taken by the three sequences using a five-point scale. Quantitative evaluations were also performed by calculating the liver-to-spleen, -lesion, and -portal vein (PV) signal intensity ratios. The results were compared between the three sequences using the Friedman test. Results: LAVA Starnavi+ showed the best image quality and hepatic vein clarity (P < 0.0001). LAVA Starnavi− showed the lowest image quality (P < 0.0001–0.0106). LAVA Starnavi+ images showed fewer streak artifacts than LAVA Starnavi− images (P < 0.0001), while Cartesian LAVAnavi+ images showed no streak artifacts. Cartesian LAVAnavi+ images showed stronger respiratory motion/pulsation artifacts than the others (P < 0.0001). LAVA Starnavi− images showed the highest liver-to-spleen ratios (P < 0.0001–0.0005). Cartesian LAVAnavi+ images showed the lowest liver-to-lesion and -PV ratios (P < 0.0001–0.0108). Conclusion: In terms of image quality, the combination of stack-of-stars acquisition and navigator echoes is the best for HBP imaging without breath-holding.
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Affiliation(s)
| | | | | | - Daiki Tamada
- Department of Radiology, University of Yamanashi
| | | | - Kang Wang
- MR Collaboration and Development, GE Healthcare
| | - Ty A Cashen
- MR Collaboration and Development, GE Healthcare
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Ersoz A, Tugan Muftuler L. Undersampled linogram trajectory for fast imaging (ULTI): experiments at 3 T and 7 T. NMR Biomed 2016; 29:340-348. [PMID: 26751051 DOI: 10.1002/nbm.3475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/18/2015] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
In this study, the performance of linogram acquisition was investigated for the reconstruction of images from undersampled data using parallel imaging methods. The point spread function (PSF) of linogram sampling was analyzed for image sharpness and artifacts. Generalized auto-calibrating partially parallel acquisition was implemented for this new sampling scheme, and images were reconstructed with high acceleration rates. The results were compared with conventional radial sampling methods using simulations and phantom experiments at 3 T. Additionally, a human volunteer was scanned at 7 T. The results demonstrated that the PSF was sharper and the mean artifact power was lower for linogram sampling compared with radial sampling. Results of simulations and phantom experiments were in accord with the findings of the PSF analysis. In simulations, errors in the reconstructed images were lower for linogram sampling. In phantom experiments, fine details and sharp edges were preserved for linogram sampling, while details were blurred for radial sampling. The in vivo human study demonstrated that linogram sampling could provide high quality images of anatomy, even at high acceleration rates. Linogram sampling not only possesses the advantages of radial sampling, such as reduced sensitivity to motion and higher acceleration rates, but it also provides sharper images with fewer artifacts. Moreover, it is less prone to off-resonance artifacts compared with radial sampling. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ali Ersoz
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - L Tugan Muftuler
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
- Center for Imaging Research, Medical College of Wisconsin, Milwaukee, WI, USA
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Huettner AM, Mickevicius NJ, Ersoz A, Koch KM, Muftuler LT, Nencka AS. Wavelet Domain Radiofrequency Pulse Design Applied to Magnetic Resonance Imaging. PLoS One 2015; 10:e0141151. [PMID: 26517262 PMCID: PMC4627821 DOI: 10.1371/journal.pone.0141151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/04/2015] [Indexed: 11/18/2022] Open
Abstract
A new method for designing radiofrequency (RF) pulses with numerical optimization in the wavelet domain is presented. Numerical optimization may yield solutions that might otherwise have not been discovered with analytic techniques alone. Further, processing in the wavelet domain reduces the number of unknowns through compression properties inherent in wavelet transforms, providing a more tractable optimization problem. This algorithm is demonstrated with simultaneous multi-slice (SMS) spin echo refocusing pulses because reduced peak RF power is necessary for SMS diffusion imaging with high acceleration factors. An iterative, nonlinear, constrained numerical minimization algorithm was developed to generate an optimized RF pulse waveform. Wavelet domain coefficients were modulated while iteratively running a Bloch equation simulator to generate the intermediate slice profile of the net magnetization. The algorithm minimizes the L2-norm of the slice profile with additional terms to penalize rejection band ripple and maximize the net transverse magnetization across each slice. Simulations and human brain imaging were used to demonstrate a new RF pulse design that yields an optimized slice profile and reduced peak energy deposition when applied to a multiband single-shot echo planar diffusion acquisition. This method may be used to optimize factors such as magnitude and phase spectral profiles and peak RF pulse power for multiband simultaneous multi-slice (SMS) acquisitions. Wavelet-based RF pulse optimization provides a useful design method to achieve a pulse waveform with beneficial amplitude reduction while preserving appropriate magnetization response for magnetic resonance imaging.
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Affiliation(s)
- Andrew M. Huettner
- Department of Biophysics, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Nikolai J. Mickevicius
- Department of Radiation Oncology, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Ali Ersoz
- Department of Neurosurgery, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Kevin M. Koch
- Department of Biophysics, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Radiology, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - L. Tugan Muftuler
- Department of Neurosurgery, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Andrew S. Nencka
- Department of Biophysics, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Radiology, The Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Agopyan A, Tekin D, Unal M, Kurtel H, Turan G, Ersoz A. Acute effects of static stretching on isokinetic thigh strength on modern dancers. J Sports Med Phys Fitness 2013; 53:538-550. [PMID: 23903535] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM The aim of this study was to examine the acute effects of static stretching in dominant leg flexor muscle groups on concentric isokinetic leg extension and flexion peak torque (PT), peak torque % body weight (PT%BW) and total work (TW) at 60, 180 and 300 °.s-1 in stretched and non-stretched limbs of modern dancers. METHODS Twenty-six trained modern dancers volunteered in this study. On the first measurement, isokinetic tests were performed on dominant and non-dominant legs. On the second measurement, the dominant leg flexors were stretched using 3 unassisted and 1 assisted static stretching exercises (each 4x15 seconds; 10-second rest). After the stretching, isokinetic tests were repeated on both legs. RESULTS The results indicated a positive increase in strength in the stretched (PT%BW, TW) and non-stretched (PT, PT%BW, TW) limbs in flexion at 180°s-1 (P<0.05). We observed a positive increase (P<0.05) in the stretched limb (180 and 300°.s-1, TW; 300°.s-1, PT%BW) in extension whereas an acute decrease (P<0.05) was observed in both legs (60˚.s-1, PT and PT%BW). CONCLUSION Our findings indicated a possible positive effect of static stretching at high angular velocities on the strength production of isokinetic contraction in stretched and non-stretched muscles. However, due to its negative effect on the extensor muscle groups, we think using static stretching is required attention before maximal strength exercises.
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Affiliation(s)
- A Agopyan
- Department of Trainer Education School of Physical Education and Sports Marmara University, Istanbul, Turkey2Department of Physiotherapy and Rehabilitation School of Health Sciences Istanbul Bilgi University, Istanbul, Turkey3Department of Physiotherapy and Rehabilitation Faculty of Health Sciences Yeni Yuzyil University, Istanbul, Turkey4Department of Sports Physiology School of Medicine, Marmara University Istanbul, Turkey5Department of Physical Education and Sports Institute of Health Sciences Marmara University, Istanbul, Turkey6Department of Music and Performing Arts Dance Program Faculty of Arts and Design Yildiz Technical University, Istanbul, Turkey -
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Ersoz A, Arpinar VE, Dreyer S, Muftuler LT. Quantitative analysis of the efficacy of gradient table correction on improving the accuracy of fiber tractography. Magn Reson Med 2013; 72:227-36. [PMID: 23922298 DOI: 10.1002/mrm.24889] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 02/13/2013] [Revised: 06/24/2013] [Accepted: 06/25/2013] [Indexed: 11/09/2022]
Abstract
PURPOSE Several groups suggested that the gradient table of a DTI data set should be reoriented to compensate for head motion. Although the effects of this correction were demonstrated qualitatively, its efficacy was not demonstrated quantitatively to date. The main goal of this study was to investigate the efficacy of gradient table correction on improving the accuracy of fiber tractography. METHODS First, the effects of gradient table correction on the estimation of fractional anisotropy (FA) maps and the primary diffusion direction were quantified and compared with the inherent uncertainty in the estimation process. Then, the effects of gradient table correction on tractography were quantified. RESULTS The corrections in FA values were only a fraction of the typical values seen in major fasciculi and inter-subject variance. The corrections to the primary diffusion direction were also much smaller than the uncertainty inherent in the estimation of its direction. However, the directional estimates were biased due to head motion and deviated fiber tracking. CONCLUSIONS Corrections to FA values were negligible and are not expected to affect group comparisons. However, a small but consistent bias was introduced to the estimates of primary diffusion direction, which might affect brain connectivity analyses based on fiber tracking.
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Affiliation(s)
- Ali Ersoz
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Abstract
PURPOSE Rapid magnetic resonance imaging (MRI) acquisition is typically achieved by acquiring all or most lines of k-space after one radio frequency (RF) excitation. Parallel imaging techniques can further accelerate data acquisition by acquiring fewer phase-encoded lines and utilizing the spatial sensitivity information of the RF coil arrays. The goal of this study was to develop a new MRI data acquisition and reconstruction technique that is capable of reconstructing a two-dimensional (2D) image using highly undersampled k-space data without any special hardware. Such a technique would be very efficient, as it would significantly reduce the time wasted during multiple RF excitations or phase encoding and gradient switching periods. METHODS The essence of this new technique is to densely sample a small number of projections, which should be acquired at an angle other than 0° or multiples of 45°. This results in multiple rays passing through a voxel and provides new and independent measurements for each voxel. Then the images are reconstructed using the unique information coming from these projections combined with RF coil sensitivity profiles. The feasibility of this new technique was investigated with realistic simulations and experimental studies using a phantom and compared with conventional nonuniform fast Fourier transform technique. Eigenvalue analysis and error calculations were conducted to find optimal projection angles and minimum requirements for dense sampling. RESULTS Reconstruction of 64 × 64 images was done using a single projection from simulated data under different noise levels. Simulated reconstruction was also tested with two projections to assess the improvement. Experimental phantom images were reconstructed at higher resolution using 4, 8, and 16 projections. Cross-sectional profiles illustrate that the new technique resolved compartment boundaries clearly. CONCLUSIONS Simulations demonstrated that only a single k-space line might be sufficient to reconstruct a 2D image using this new technique. Experimental results showed that this is a promising new technique for fast imaging. Using the information from the simulations and fast imaging parameters published in the literature, it could be predicted that a two-dimensional image could be acquired in about 10 ms. One of the major advantages of this new technique is that it does not require any additional hardware and can be implemented on a conventional scanner with an eight-channel coil.
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Affiliation(s)
- Ali Ersoz
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Guo Z, Ersoz A, Butterfield DA, Mattson MP. Beneficial effects of dietary restriction on cerebral cortical synaptic terminals: preservation of glucose and glutamate transport and mitochondrial function after exposure to amyloid beta-peptide, iron, and 3-nitropropionic acid. J Neurochem 2000; 75:314-20. [PMID: 10854276 DOI: 10.1046/j.1471-4159.2000.0750314.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [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: 11/20/2022]
Abstract
Recent studies have shown that rats and mice maintained on a dietary restriction (DR) regimen exhibit increased resistance of neurons to excitotoxic, oxidative, and metabolic insults in experimental models of Alzheimer's, Parkinson's, and Huntington's diseases and stroke. Because synaptic terminals are sites where the neurodegenerative process may begin in such neurodegenerative disorders, we determined the effects of DR on synaptic homeostasis and vulnerability to oxidative and metabolic insults. Basal levels of glucose uptake were similar in cerebral cortical synaptosomes from rats maintained on DR for 3 months compared with synaptosomes from rats fed ad libitum. Exposure of synaptosomes to oxidative insults (amyloid beta-peptide and Fe(2+)) and a metabolic insult (the mitochondrial toxin 3-nitropropionic acid) resulted in decreased levels of glucose uptake. Impairment of glucose uptake following oxidative and metabolic insults was significantly attenuated in synaptosomes from rats maintained on DR. DR was also effective in protecting synaptosomes against oxidative and metabolic impairment of glutamate uptake. Loss of mitochondrial function caused by oxidative and metabolic insults, as indicated by increased levels of reactive oxygen species and decreased transmembrane potential, was significantly attenuated in synaptosomes from rats maintained on DR. Levels of the stress proteins HSP-70 and GRP-78 were increased in synaptosomes from DR rats, consistent with previous data suggesting that the neuroprotective mechanism of DR involves a "preconditioning" effect. Collectively, our data provide the first evidence that DR can alter synaptic homeostasis in a manner that enhances the ability of synapses to withstand adversity.
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Affiliation(s)
- Z Guo
- Sanders-Brown Research Center on Aging. Department of Chemistry and Center of Membrane Sciences, University of Kentucky, Lexington, Kentucky, USA
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Sinci V, Kalaycioglu S, Gunaydin S, Imren Y, Gokgoz L, Soncul H, Ersoz A. Evaluation of heparin-coated circuits with full heparin dose strategy. Ann Thorac Cardiovasc Surg 1999; 5:156-63. [PMID: 10413761] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
Heparin-coated cardiopulmonary circuits (HCC) in combination with a reduced systemic heparin dose has been demonstrated to reduce postoperative hemorrhage after cardiac surgery. But, it has still been equivocal whether this effect was related to the improved bio-compatibility or to the reduced exposure of the circulating heparin. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into two groups either to be operated by HCC (30 patients) or uncoated but otherwise identical circuits (NHCC). Full systemic heparinization was induced in both groups. Hemodynamic parameters, hematological and biocompatibility tests were monitored within 24 hours. Postoperative blood loss, requirements for transfusions, clinical performance were recorded. Arterial filters were examined electron microscopically. Platelet levels remained significantly higher in the HCC group starting at the tenth minute following the institution of cardiopulmonary bypass until postoperative 24 hours. Electron microscopy showed significantly more platelet adhesion and pseudopod formation in the NHCC group. The mean amount of shed pleural and mediastinal blood measured from the time of the sternal closure was significantly lower in the HCC group (316 +/- 30 cc for HCC and 550 +/- 35 cc for NHCC). Mean postoperative transfusion requirements were also lower in the HCC group (230 +/- 23 cc for HCC and 320 +/- 25 cc for NHCC). The use of HCC and full systemic heparinization did not change the inflammatory response or biocompatibility but demonstrated benefits in platelet preservation and postoperative bleeding.
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Affiliation(s)
- V Sinci
- Department of Thoracic and Cardiovascular Surgery, Gazi University School of Medicine, Ankara, Turkey
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Gokgoz L, Gunaydin S, Sinci V, Unlu M, Boratav C, Babacan A, Soncul H, Halit V, Inanir S, Ersoz A. Psychiatric complications of cardiac surgery postoperative delirium syndrome. SCAND CARDIOVASC J 1997; 31:217-22. [PMID: 9291540 DOI: 10.3109/14017439709041749] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [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: 02/05/2023]
Abstract
Psychiatric disturbances due to cardiopulmonary bypass, especially postoperative delirium syndrome, are among the immediate complications of open-heart surgery. In a series of 32 male and 18 female patients the prevalence of such disorders was investigated and search was made for possible risk factors for their occurrence. Psychiatric, neurologic and electroencephalographic evaluation was made pre- and postoperatively, in addition to haemodynamic, echocardiographic, angiographic and regional cerebral blood flow studies. Nine of the 50 patients had significantly reduced perfusion of certain cerebral lobes in single photon emission computed tomography, and in six of them the psychiatric tests indicated postoperative delirium; three of these six also had moderate electroencephalographic changes. The cerebral hypoperfusion persisted on day 15 in four patients, while psychiatric tests were negative. The study showed possible risk factors to be patient age, long aortic cross-clamp time, high-dose inotropic support and excessive transfusion of blood or blood products.
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Affiliation(s)
- L Gokgoz
- Department of Cardiovascular Surgery, Gazi University, School of Medicine, Ankara, Turkey
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Erbas D, Soncul H, Turkozkan N, Arioioglu A, Muftugoglu S, Ersoz A. Effect of selenium on ischemic and reperfusion injury in isolated guinea pig lungs. Gen Pharmacol 1995; 26:1669-72. [PMID: 8745154 DOI: 10.1016/0306-3623(95)00027-5] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. An experimental comparative study on isolated guinea pig lungs was carried out to determine the effect of selenium added to pulmoplegic solution on ischemic lung preservation. 2. Two different types of solutions (Eurocollins in control group and Eurocollins + selenium 10(-3) M in experimental group) were infused before 3 hr of normothermic ischemia. 3. Tissue malone dialdehyde (MDA) and tissue glutathione (GSH) levels were assessed before the ischemic period, after the ischemia and at the end of reperfusion. Electron microscopic changes were also studied at the end of reperfusion to compare the cellular injury between the groups. 4. Addition of selenium before the ischemic period relatively decreased tissue MDA levels after reperfusion but did not alter tissue GSH levels.
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Affiliation(s)
- D Erbas
- Department of Physiology, Gazi University Medical Faculty, Ankara, Turkey
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Sinci V, Soncul H, Gunaydin S, Halit V, Gokgoz L, Tatlican O, Yener A, Bilgehan A, Ersoz A. The effects of thyroid hormones on the heart following global ischemia. A clinical and experimental study. Jpn Heart J 1994; 35:443-54. [PMID: 7967049 DOI: 10.1536/ihj.35.443] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cardiopulmonary bypass is associated with a reduction in plasma thyroid hormone concentrations in patients undergoing cardiac surgery. However, studies of the effects of cardiopulmonary bypass on thyroid function are limited and many studies report conflicting data concerning only the period of cardiopulmonary bypass. In this study, we tried to clinically determine the effects of cardiopulmonary bypass on concentrations of thyroid hormones by comprehensive thyroid function tests in 10 patients before and after surgery, and observed the benefits of triiodothyronine supplementation after global ischemia on myocardial function experimentally in guinea pigs. In patients undergoing surgery, concentrations of total triiodothyronine and free triiodothyronine decreased progressively on the institution of cardiopulmonary bypass and remained below normal levels until 24 hours postoperatively. In the guinea pig hearts studied in a Langendorf perfusion apparatus, T3 supplementation enhanced percentage recovery of ventricular contractile force, heart work and heart rate with respect to other groups receiving no T3 supplementation or T3 supplementation without any ischemic interval.
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Affiliation(s)
- V Sinci
- Department of Cardiovascular Surgery, Gazi University, School of Medicine, Ankara, Turkey
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Yener A, Gokgoz L, Soncul H, Sezgin A, Ersoz A, Sinci V. Nonpenetrating thoracic trauma causing dissection of the interventricular septum and leading to complete heart block. J Thorac Cardiovasc Surg 1992; 103:820-3. [PMID: 1548929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Ross BA, Hosseini H, Clement AJ, Ersoz A, Braimbridge MV. Results of 100 consecutive mitral valve replacement operations using Starr-Edwards prostheses in a general hospital. Heart 1973; 35:556. [PMID: 4716032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Simpkin P, Brown AH, Ersoz A, Braimbridge MV. Chronic left heart tamponade. J Thorac Cardiovasc Surg 1973; 65:531-3. [PMID: 4266812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
A technique of external DC defibrillation during open heart surgery is described. It has proved of value in second operations and has been consistently successful except in some patients with aortic valve disease and massive left ventricles.
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