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  • 1
    Electronic Resource
    Electronic Resource
    Prediction of the Recurrence of Atrial Fibrillation After Successful Cardioversion with P Wave Signal-Averaged ECG (2005)
    350 Main Street , Malden , MA 02148 , USA , and 9600 Garsington Road , Oxford OX4 2XG , UK . : Blackwell Publishing, Inc.
    Annals of noninvasive electrocardiology 10 (2005), S. 0 
    Details
    ISSN: 1542-474X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: The recurrence of atrial fibrillation (AF) was often observed after cardioversion. Methods: In our study, a P wave triggered P wave signal-averaged ECG (P-SAECG) was performed on 118 consecutive patients 1 day after successful electrical cardioversion in order to evaluate the utility of this method to predict AF after cardioversion. We measured the filtered P wave duration (FPD) and the root mean square voltage of the last 20 ms of the P wave (RMS 20). Results: During a 1-year follow-up, a recurrence was observed in 57 patients (48%). Patients with recurrence of AF had a larger left atrial size (41.9 ± 4.0 vs 39.3 ± 3.1 mm, P 〈 0.0003), a longer FPD (139.6 ± 16.0 vs 118.2 ± 14.1 ms, P 〈 0.0001), and a lower RMS 20 (2.57 ± 0.77 vs 3.90 ± 0.99 μV, P 〈 0.0001). A cutoff point (COP) of FPD ≥126 ms and RMS 20 ≤3.1 μV could predict AF with a specificity of 77%, a sensitivity of 72%, a positive value of 75%, a negative predictive value of 75%, and an accuracy of 75%. A stepwise logistic regression analysis of variables identified COP (odds ratio 9.97; 95% CI, 4.10–24.24, P 〈 0.0001) as an independent predictor for recurrence. Conclusions: We conclude that the probability of recurrence of AF after cardioversion could be predicted by P-SAECG. This method seems to be appropriate to demonstrate a delayed atrial conduction that might be a possible risk factor of reinitiation of AF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1542-474X.2005.00059.x
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  • 2
    Electronic Resource
    Electronic Resource
    Electrocardiographic abnormalities during recovery from ultra-short opiate detoxification (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Addiction biology 4 (1999), S. 0 
    Details
    ISSN: 1369-1600
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of this study was to detect electrocardiographic abnormalities during recovery from ultra-short opiate detoxification, using a retrospective study design conducted at a university hospital. Twenty-two consecutive patients (mean±SD, age 30.0±6.3 years) receiving daily oral methadone underwent ultrashort opiate detoxification under general anaesthesia. In the post-anaesthetic stages they received oral clonidine and naltrexone, and in some cases trimipramine was dispensed. Heart rate, rate-corrected QT interval (msec) and repolarization abnormalities of 12-lead electrocardiographic recordings before and after detoxification were examined. The serum electrolyte concentrations (mmol/l) including Na+, K+ and Ca2+ were assessed. Eightyone ECGs were evaluated in total. Compared to the initial values, heart rate was significantly lowered in the first two tracings after detoxification (median values 60.0/min. vs. 52,5/min; p=0.0006). The lowest heart rate measured after detoxification was 44/min. The cQT interval was significantly lengthened (median value 420 msec vs. 453 msec after detoxification). In 16 tracings (20%) taken from 10 patients (45%) cQT rose above 460 msec and in two tracings (2%) it topped 500 msec. Modest hypokalaemia (2.9–3.5 mmol/l) was linked to cQT prolongation (460 msec) in 10 ECG tracings. Spearman's correlation coefficient indicated that prolonged cQT intervals correlated with decreased potassium values. Twelve tracings (15%) taken from 10 patients (45%) after detoxification showed T-wave inversion and in two cases sinus rhythm was turned into a rhythm arising from the atrioventricular node. Serum potassium was significantly lowered (median values 4.3 v.s 3.8 mmol/l, p=0.0001). The Ca2+ concentration fell significantly (2.4 vs. 2.2 mmol/l, p=0.0001) but not below the normal range. It was concluded that ultra-short opiate detoxification carries the risk of QTprolongation and bradycardia. These side effects are reversible and can be explained by hypokalaemia and clonidine medication, the effects of which might reinforce each other. To avoid arrhythmic complications, ECG tracings should be carried out regularly during recovery, i.e. at least daily, for a span of 3 days after discharge from the intensive care unit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1080/13556219971551
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  • 3
    Electronic Resource
    Electronic Resource
    Atrial Fibrillatory Electrogram Measurement Allows Atrial Lead Placement in Patients Who Develop Atrial Fibrillation During Permanent Dual Chamber Pacemaker Implantation (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 21 (1998), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The benefit of DDD(R) pacing is proven even in patients with intermittent atrial fibrillation. Atrial fibrillation developing during dual chamber pacemaker implantation creates a difficult problem. Maneuvers to reestablish a stable atrial rhythm often are required if atrial fibrillation sets in. This study was performed to determine if atrial lead placement can be performed with acceptable long-term results in the presence of atrial fibrillation. Twenty-one patients in whom atrial fibrillation developed during permanent pacemaker implantation were included in this study. In 12 patients, episodes of intermittent atrial fibrillation had been documented before the procedure. Screw-in leads were used in 15 patients and J-shaped passive fixation leads in 6 patients. AH leads were bipolar. The intraoperative atrial fibrillation electrogram amplitudes ranged from 0.9 to 3.2 mV (mean 1.8 ± 0.6 mV). One patient required lead revision due to a high atrial pacing threshold after conversion to SR. One patient remained in atrial fibrillation at 3-month follow-up. The other 20 patients converted to SR, 11 of whom had intermittent atrial fibrillation with successful mode switch activation. P wave amplitudes were 2.8 ± 6 mV (range 1.4 to 4.0 mV) after conversion to SR. The mean atrial pacing threshold was 1.1 ± 0.5 V (range 0.5 to 3.5 V). Placement of atrial leads in patients who develop atrial fibrillation during pacemaker implantation is feasible; fibrillatory electrogram amplitudes showed a good correlation with the atrial signal after conversion to an organized atrial rhythm (r = 0.698). Acceptable atrial pacing thresholds can be expected as well.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1998.tb01170.x
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  • 4
    Electronic Resource
    Electronic Resource
    Myocardial Lactate Extraction during Repeated Fibrillation/Defibrillation Episodes in Defibrillator Implantation Testing (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 21 (1998), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Intraoperative testing with several fibrillation/defibrillation episodes (FDEs) is routiinely performed during defibrillator implantation. Testing is considered safe even in patients with severe cardiac impairment, provided the recovery timespans and number of FDEs are adapted to the individual patient. Myocardial lactate extraction (MLE) was examined in two testing protocols. In 30 patients with coronary artery disease defibrillator implantations were performed under intravenous anesthesia. A percutaneous catheter was positioned into the coronary sinus(CS) under fluoroscopy. Two groups were randomly formed: group A (n = 20, mean number of FDEs: 4.2/patient) with 2 minutes waiting time between FDEs, and group B(n = 10. mean number of EDEs 4.1/ patients) with 10 minutes between FDEs. Defibrillation pulses were released 15 seconds after T wave shock induced fibrillation. To estimate MLE. arterial and CS blood samples were collected before and after each FDE. After the last FDE, samples were obtained after 5, 10, and up to 20 minutes. In group A, MLE fell from a baseline value of 29.6%± 3.6% before the FDEs to 7.8%± 5.4% immediately after the episodes. MLE recovered to 27.2%± 6.5% within 1 minute and overshot to 35.6%± 5.8% within 5 minutes. In group B, MLE decreased from 37.6%± 7.5% to 15.1%± 8.1% immediately after each EDE and rose to its original value (33.6 ± 7.8) within the 5-minute recovery period. MLE decreased immediately after each FDE, and recovered within 1 minute even in poor left ventricular function. For full MLE recovery a 2-minute wait between episodes is sufficient, if the total number of FDEs does not exceed four.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1998.tb00281.x
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  • 5
    Electronic Resource
    Electronic Resource
    Does remodeling occur in the diseased human saphenous vein bypass grafts? An intravascular ultrasound study (1999)
    Springer
    The international journal of cardiovascular imaging 15 (1999), S. 295-300 
    Details
    ISSN: 1573-0743
    Keywords: atherosclerosis ; intravascular ultrasound ; remodeling ; saphenous vein bypass graft
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Coronary artery remodeling is a common phenomenon in human atherosclerotic arteries. Controversies exist concerning the presence of absence of the remodeling process in diseased human coronary saphenous vein bypass grafts. The purpose of the study was to observe the vessel and lumen dimensions in patients who had undergone saphenous vein grafting with intravascular ultrasound to find out whether the remodeling process exists in the diseased human saphenous vein bypass grafts. Methods: A total of 43 saphenous vein bypass grafts from 43 patients (39 males, 4 females, mean age 63 ± 8 years); 1–16 years (mean 9.3 ± 4.0 years) after grafting, who had not undergone previous catheter intervention, were studied using intravascular ultrasound. The vessel, lumen and plaque area were measured at the lesion segment as well as in the proximal and distal reference segments. The percent stenosis was calculated. Results: In 43 bypass grafts having severe stenosis before intervention, plaque was eccentric in 69.4% and concentric in 30.6%. No calcification was detected in 75% cases and 25% cases has mild-moderate intimal calcification. The vessel area in the lesion segment was 19.0 ± 9.7 mm2, significantly larger than the proximal reference segment 12.8 ± 4.0 mm2 as well as the distal reference segment 12.9 ± 3.6 mm2 (p 〈 0.001). It was also larger than that of the average area of the proximal and distal reference segments (p 〈 0.001). The vessel area increased in accordance with plaque area (p 〈 0.001). A weak relationship existed between vessel area and percent stenosis (r = 0.37, p = 0.04). Conclusion: In contrary to previous findings, diseased human saphenous vein bypass grafts undergo focal compensatory enlargement (remodeling) in the presence of plaque formation. The underlying mechanism is probably similar to that in de novo atherosclerosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006125205217
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  • 6
    Electronic Resource
    Electronic Resource
    Time course of mitosis and collateral growth following coronary microembolization in the porcine heart (1997)
    Springer
    Cell & tissue research 287 (1997), S. 583-590 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Mitosis ; Gene expression ; Histone H3 ; PCNA (proliferating cell nuclear antigen) ; Microembolization ; Angiogenesis ; Pig (Landrace)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In ischaemic porcine myocardium, the growth of collateral vessels by angiogenesis is observed in clusters in the vicinity of focal necroses. Because mitosis of endothelial cells is a prerequisite for angiogenesis, the purpose of this study has been to evaluate the time course of mitosis as an indicator of vascular growth in a porcine model of coronary microembolization. Ischaemia was induced by injection of 25-µm microspheres in the left circumflex artery, followed by tissue collection from non-ischaemic and ischaemic areas of the same heart after 24, 72 or 168 h microembolization. Tissue was studied by histone H3 in-situ hybridization, PCNA/cyclin immunohistochemistry and electron microscopy. The number of blood vessels in ischaemic myocardium was compared with that in normal control tissue. Capillary growth started as early as 24 h after microembolization, as indicated by increasing numbers of proliferating, histone H3- and PCNA/cyclin-positive cells in the necrotic inflammatory foci of the ischaemic area. At 72 h and 168 h, the number of blood vessels was significantly higher in ischaemic than in normal myocardium, whereas at 168 h, mitosis of cells was, as in normal myocardium, a rare event. Coronary microembolization of porcine myocardium thus leads to an increased cellular proliferation rate between 24 h and less than 7 days after the onset of microembolization, followed by enhanced capillary growth. In-situ hybridization with histone H3 and PCNA/cyclin immunohistochemistry seem to be reliable markers for proliferation and vascular growth in non-cancerogenic tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050781
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  • 7
    Electronic Resource
    Electronic Resource
    Herzinsuffizienz als kardiale Manifestation einer Sarkoidose Erfolgreiche Therapie der Herzinsuffizienz mit Steroiden, Digitalis und einem Angiotensin-1-Rezeptor-Antagonisten bei Sarkoidose (2000)
    Springer
    Medizinische Klinik 95 (2000), S. 151-157 
    Details
    ISSN: 1615-6722
    Keywords: Schlüsselwörter Sarkoidose ; Morbus Boeck ; Herzinsuffizienz ; Myokardbeteiligung ; Medikamentöse Therapie ; Key words Sarcoidosis ; Boeck's disease ; Congestive heart failure ; Myocardial manifestation ; Drug therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Background: Sarcoidosis is a multisystemic disorder that may involve every organ. A symptomatic manifestation of the myocardium is possible, in these cases arrhythmias are the most common symtpoms. Case Report: This case report presents a 26-year-old female with the recurrence of Boeck's sarcoid. Fever, chill and a severe reduction in stress tolerance were the first symtoms. At the time of admission she complained of Grade III dyspnea according to the NYHA classification. The echocardiogram showed a severe impairment of the global and left ventricular function. The left ventricular ejection fraction was reduced to 30% and the Tei index was elevated to 1,0. A specimen taken from a mediastinal tumor confirmed the hypothesis of the recurrence of the sarcoidosis. Myocardial perfusion scintigraphy showed typical leasions for myocardial sarcoidosis. There were signs of an old anteroseptal infarction in the resting ECG without evidence of myocardial ischemia during a stress test. Repeated Holter-ECGs were without signs of severe arrhythmias whereas ventricular late potentials were positive. After the combined therapy with steroids, digitalis and an angiotensin-1 receptor antagonist, mediastinal mass and Tei index were reduced and the ejection fraction moved to 56%. Dyspnoe was classified with Grade II according to the NYHA classification. Conclusion: Treatment of asymptomatic sarcoidosis is still controversial, whereas the treatment of life-threatening sarcoidosis, eye involvement of severe hypercalcemia is accepted. This case report presents the successful treatment of severe heart failure with predinisone, glycosides and an angiotensin-1 receptor antagonist. With this combined therapy an improvement of subjective and objective parameters was possible.
    Notes: Zusammenfassung Hintergrund: Bei der Sarkoidose handelt es sich um eine Multisystemerkrankung, bei der grundsätzlich alle Organe betroffen sein können. Eine symptomatische Herzbeteiligung ist möglich und äußert sich meist in Form von Herzrhythmusstörungen. Fallbeschreibung: Wir berichten über eine 26jährige Patientin, bei der es zu einem Rezidiv eines Morbus Boeck mit ausgeprägter kardialer Symptomatik kam. Neben Fieber und Schüttelfrost bestand bei der Patientin eine massive Beeinträchtigung der körperlichen Leistungsfähigkeit. Bei stationärer Aufnahme litt sie unter einer Dyspnoe im NYHA-Stadium III. Die Echokardiographie zeigte mit einer Ejektionsfraktion von 30% und einem Tei-Index von 1,0 eine massive Einschränkung der linksventrikulären und globalen Funktion. Bei gleichzeitiger mediastinaler Raumforderung konnte das Rezidiv der Sarkoidose bioptisch gesichert werden. Die Thalliummyokardzintigraphie zeigte typische Veränderungen für eine myokardiale Beteiligung. Bei Hinweisen auf einen stattgehabten Anteroseptalinfarkt im EKG fanden sich positive Spätpotentiale im signalgemittelten EKG ohne einen Hinweis auf eine belastungsabhängige Ischämie in der Ergometrie oder Herzrhythmusstörungen im Holter-EKG. Angesichts des schweren Krankheitsbildes begannen wir eine immunsuppressive Therapie mit Prednison sowie eine Herzinsuffizienztherapie mit einem Digitalisglykosid und einem Angiotensin-1-Rezeptor-Antagonisten. Nach Abschluß der Therapie hatte sich die mediastinale Raumforderung zurückgebildet, der Tei-Index betrug nur noch 0,6, und die linksventrikuläre Ejektionsfraktion war auf 56% angestiegen, Dyspnoe bestand nur noch bei stärkerer körperlicher Belastung (NYHA II). Schlußfolgerung: Die Behandlung einer asymptomatischen Verlaufsform der Sarkoidose ist umstritten. Es besteht jedoch Konsens darüber, daß bei vitaler Gefährdung, Augenbeteiligung oder massiver Hyperkalzämie eine immunsuppressive Therapie indiziert ist. Der vorliegende Fallbericht schildert die erfolgreiche Therapie einer symptomatischen, schweren Herzinsuffizienz mittels immunsuppressiver Therapie mit Prednison in Verbindung mit einem Digitalisglykosid und einem Angiotensin-1-Rezeptor-Antagonisten. Mit dieser Kombinationstherapie konnte die Beeinträchtigung der Patientin durch die schwere Herzinsuffizienz nach subjektiven und objektiven Parametern deutlich vermindert werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00002097
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  • 8
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    Protection against malaria at 1 year and immune correlates following PfSPZ vaccination (2016)
    Andrew S Ishizuka; Kirsten E Lyke; Adam De; Zure; Andrea A Berry; Thomas L Richie; Floreliz H Mendoza; Mary E Enama; Ingelise J Gordon; Lee-Jah Chang; Uzma N Sarwar; Kathryn L Zephir; La; Sonji A Holman; Eric R James; Peter F Billingsley; Anusha Gunasekera; Sumana Chakravarty; Anita Manoj; Ming; Lin Li; Adam J Ruben; Tao Li; Abraham G Eappen; Richard E Stafford; Natasha K CTooba Murshedkar; Hope De; Cederfelt; Sarah H Plummer; Cynthia S Hendel; Laura Novik; Pamela J M Costner; Jamie G Saunders; Matthew B Laurens; Christopher V Plowe; Barbara Flynn; William R Whalen; J P Todd; Jay Noor; Srinivas Rao; Kailan Sierra-Davidson; Geoffrey M Lynn; Judith E Epstein; Margaret A Kemp; Gary A Fahle; Sebastian A Mikolajczak; Matthew Fishbaugher; Brandon K Sack; Stefan H I Kappe; Silas A Davidson; Lindsey S Garver; Niklas K Björkström; Martha C Nason; Barney S Graham; Mario Roederer; B Kim Lee Sim; Stephen L Hoffman; Julie E Ledgerwood; Robert A Seder
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2016-06-08
    Description: Nature Medicine 22, 614 (2016). doi:10.1038/nm.4110 Authors: Andrew S Ishizuka, Kirsten E Lyke, Adam DeZure, Andrea A Berry, Thomas L Richie, Floreliz H Mendoza, Mary E Enama, Ingelise J Gordon, Lee-Jah Chang, Uzma N Sarwar, Kathryn L Zephir, LaSonji A Holman, Eric R James, Peter F Billingsley, Anusha Gunasekera, Sumana Chakravarty, Anita Manoj, MingLin Li, Adam J Ruben, Tao Li, Abraham G Eappen, Richard E Stafford, Natasha K C, Tooba Murshedkar, Hope DeCederfelt, Sarah H Plummer, Cynthia S Hendel, Laura Novik, Pamela J M Costner, Jamie G Saunders, Matthew B Laurens, Christopher V Plowe, Barbara Flynn, William R Whalen, J P Todd, Jay Noor, Srinivas Rao, Kailan Sierra-Davidson, Geoffrey M Lynn, Judith E Epstein, Margaret A Kemp, Gary A Fahle, Sebastian A Mikolajczak, Matthew Fishbaugher, Brandon K Sack, Stefan H I Kappe, Silas A Davidson, Lindsey S Garver, Niklas K Björkström, Martha C Nason, Barney S Graham, Mario Roederer, B Kim Lee Sim, Stephen L Hoffman, Julie E Ledgerwood & Robert A Seder
    Print ISSN: 1078-8956
    Electronic ISSN: 1546-170X
    Topics: Biology , Medicine
    Published by Nature Publishing Group (NPG)
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  • 9
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    Corrigendum: Protection against malaria at 1 year and immune correlates following PfSPZ vaccination (2016)
    Andrew S Ishizuka; Kirsten E Lyke; Adam De; Zure; Andrea A Berry; Thomas L Richie; Floreliz H Mendoza; Mary E Enama; Ingelise J Gordon; Lee-Jah Chang; Uzma N Sarwar; Kathryn L Zephir; La; Sonji A Holman; Eric R James; Peter F Billingsley; Anusha Gunasekera; Sumana Chakravarty; Anita Manoj; Ming; Lin Li; Adam J Ruben; Tao Li; Abraham G Eappen; Richard E Stafford; Natasha K CTooba Murshedkar; Hope De; Cederfelt; Sarah H Plummer; Cynthia S Hendel; Laura Novik; Pamela J M Costner; Jamie G Saunders; Matthew B Laurens; Christopher V Plowe; Barbara Flynn; William R Whalen; J P Todd; Jay Noor; Srinivas Rao; Kailan Sierra-Davidson; Geoffrey M Lynn; Judith E Epstein; Margaret A Kemp; Gary A Fahle; Sebastian A Mikolajczak; Matthew Fishbaugher; Brandon K Sack; Stefan H I Kappe; Silas A Davidson; Lindsey S Garver; Niklas K Björkström; Martha C Nason; Barney S Graham; Mario Roederer; B Kim Lee Sim; Stephen L Hoffman; Julie E Ledgerwood; Robert A Seder
    Nature Publishing Group (NPG)
    Details
    Publication Date: 2016-06-08
    Description: Nature Medicine 22, 692 (2016). doi:10.1038/nm0616-692c Authors: Andrew S Ishizuka, Kirsten E Lyke, Adam DeZure, Andrea A Berry, Thomas L Richie, Floreliz H Mendoza, Mary E Enama, Ingelise J Gordon, Lee-Jah Chang, Uzma N Sarwar, Kathryn L Zephir, LaSonji A Holman, Eric R James, Peter F Billingsley, Anusha Gunasekera, Sumana Chakravarty, Anita Manoj, MingLin Li, Adam J Ruben, Tao Li, Abraham G Eappen, Richard E Stafford, Natasha K C, Tooba Murshedkar, Hope DeCederfelt, Sarah H Plummer, Cynthia S Hendel, Laura Novik, Pamela J M Costner, Jamie G Saunders, Matthew B Laurens, Christopher V Plowe, Barbara Flynn, William R Whalen, J P Todd, Jay Noor, Srinivas Rao, Kailan Sierra-Davidson, Geoffrey M Lynn, Judith E Epstein, Margaret A Kemp, Gary A Fahle, Sebastian A Mikolajczak, Matthew Fishbaugher, Brandon K Sack, Stefan H I Kappe, Silas A Davidson, Lindsey S Garver, Niklas K Björkström, Martha C Nason, Barney S Graham, Mario Roederer, B Kim Lee Sim, Stephen L Hoffman, Julie E Ledgerwood & Robert A Seder
    Print ISSN: 1078-8956
    Electronic ISSN: 1546-170X
    Topics: Biology , Medicine
    Published by Nature Publishing Group (NPG)
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  • 10
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    Increasing the spatial resolution and sensitivity of magnetic resonance elastography by correcting for subject motion and susceptibility-induced image distortions (2016)
    Wiley-Blackwell
    Details
    Publication Date: 2016-10-21
    Description: Purpose To improve the resolution of elasticity maps by adapting motion and distortion correction methods for phase-based magnetic resonance imaging (MRI) contrasts such as magnetic resonance elastography (MRE), a technique for measuring mechanical tissue properties in vivo. Materials and Methods MRE data of the brain were acquired with echo-planar imaging (EPI) at 3T ( n  = 14) and 7T ( n  = 18). Motion and distortion correction parameters were estimated using the magnitude images. The real and imaginary part of the complex MRE data were corrected separately and recombined. The width of the point-spread function (PSF) and the position variability were calculated. The images were normalized to the Montreal Neurological Institute (MNI) anatomical template. The gray-to-white matter separability of the elasticity maps was tested. Results Motion correction sharpened the | G *| maps as demonstrated by a narrowing of the PSF by 0.78 ± 0.51 mm at 7T and 0.52 ± 0.63 mm at 3T. The amount of individual head motion during MRE acquisition correlated with the decrease in the width of the PSF at 7T ( r  = 0.53, P  = 0.025) and at 3T ( r  = 0.69, P  = 0.006) and with the increase of gray-to-white matter separability after motion correction at 7T ( r  = 0.64, P  = 0.0039) and at 3T ( r  = 0.57, P  = 0.0319). Improved spatial accuracy after distortion correction results in a significant increase in separability of gray and white matter stiffness ( P  = 0.0067), especially in inferior parts of the brain suffering from strong B 0 inhomogeneities. Conclusion We demonstrate that our method leads to sharper images and higher spatial accuracy, raising the prospect of the investigation of smaller brain areas with increased sensitivity in studies using MRE. Level of Evidence: 1 J. Magn. Reson. Imaging 2016.
    Print ISSN: 1053-1807
    Electronic ISSN: 1522-2586
    Topics: Medicine
    Published by Wiley-Blackwell
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