GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Off‐resonance based assessment of metallic wear debris near total hip arthroplasty
    Wiley ; 2018
    In:  Magnetic Resonance in Medicine Vol. 79, No. 3 ( 2018-03), p. 1628-1637
    Details
    In: Magnetic Resonance in Medicine, Wiley, Vol. 79, No. 3 ( 2018-03), p. 1628-1637
    Abstract: The presence of metallic debris near total hip arthroplasty can have a significant impact on longitudinal patient management. Methods for magnetic resonance imaging‐based quantification of metallic debris near painful total hip replacements are described and applied to cohorts of symptomatic and control subject cases. Methods A combination of metal artifact reduction, off‐resonance mapping, off‐resonance background removal, and spatial clustering methods are utilized to quantify off‐resonance signatures in cases of suspected metallosis. These methods are applied to a cohort of symptomatic hip arthroplasties composed of cobalt‐chromium alloys. Magnetostatic simulations and theoretical principles are used to illuminate the potential sources of the measured off‐resonance effects. Reported metrics from histological tissue assays extracted during surgical revision procedures are also correlated with the proposed magnetic resonance imaging‐based quantification results. Results The presented methods identified quantifiable metallosis signatures in more than 70% of the symptomatic and none of the control cases. Preliminary correlations of the MR data with direct histological evaluation of retrieved tissue samples indicate that the observed off‐resonance effect may be related to tissue necrosis. Conclusions Magnetostatic simulations, theoretical principles, and preliminary histological trends suggest that disassociated cobalt is the source of the observed off‐resonance signature. Magn Reson Med 79:1628–1637, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
    Type of Medium: Online Resource
    ISSN: 0740-3194 , 1522-2594
    URL: Issue
    URL: Article
    DOI: 10.1002/mrm.v79.3
    DOI: 10.1002/mrm.26807
    Language: English
    Publisher: Wiley
    Publication Date: 2018
    detail.hit.zdb_id: 1493786-4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Imaging of Physeal Injury : Overuse
    SAGE Publications ; 2015
    In:  Sports Health: A Multidisciplinary Approach Vol. 7, No. 2 ( 2015-03), p. 142-153
    Details
    In: Sports Health: A Multidisciplinary Approach, SAGE Publications, Vol. 7, No. 2 ( 2015-03), p. 142-153
    Abstract: As the intensity of youth participation in athletic activities continues to rise, the number of overuse injuries has also increased. A subset of overuse injuries involves the physis, which is extremely susceptible to injury. This paper aims to review the utility of the various imaging modalities in the diagnosis and management of physeal injuries in the skeletally immature population. Evidence Acquisition: A search for the keywords pediatric, physis, growth plate, x-ray, computed tomography, magnetic resonance imaging, and overuse injury was performed using the PubMed database. No limits were set for the years of publication. Articles were reviewed for relevance with an emphasis on the imaging of growth plate injuries. Study Design: Retrospective literature review. Level of Evidence: Level 4. Results: Three major imaging modalities (radiographs, computed tomography, and magnetic resonance imaging) complement each other in the evaluation of pediatric patients with overuse injuries. However, magnetic resonance imaging is the only modality that offers direct visualization of the physis, and it also offers the best soft tissue contrast for evaluating the other periarticular structures for concomitant injury. Conclusion: Imaging has an important role in the diagnosis of physeal injuries, and the information it provides has a tremendous impact on the subsequent management of these patients.
    Type of Medium: Online Resource
    ISSN: 1941-7381 , 1941-0921
    URL: Article
    DOI: 10.1177/1941738114559380
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2015
    detail.hit.zdb_id: 2474978-3
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Flexible longitudinal magnetization contrast in spectrally overlapped 3D‐MSI metal artifact reduction sequences: Technical considerations and clinical impact
    Wiley ; 2015
    In:  Magnetic Resonance in Medicine Vol. 74, No. 5 ( 2015-11), p. 1349-1355
    Details
    In: Magnetic Resonance in Medicine, Wiley, Vol. 74, No. 5 ( 2015-11), p. 1349-1355
    Abstract: It has previously been demonstrated that increased overlap of spectral bins in three‐dimensional multispectral imaging techniques (3D‐MSI) can aid in reducing residual artifacts near metal implants. However, increasing spectral overlap also necessitates consideration of saturation effects for species with long T 1 values. Here, an interleaved spectral bin acquisition strategy is presented for overlapping 3D‐MSI that allows for flexible choice of repetition times while simultaneously addressing these cross talk concerns. Methods A phantom imaging experiment is used to illustrate the amplified effect of cross talk on 3D‐MSI acquisitions. A methodological approach to address cross talk across a variety of prescribed repetition times is then described. Using the presented principles, a clinical subject with a total hip replacement was imaged to generate T 1 , proton density, and short‐tau inversion recovery contrasts. In addition, a fracture instrumentation case was imaged pre‐ and postcontrast using T 1 ‐weighted spectrally overlapped 3D‐MSI. Results Phantom results demonstrate that conventional spectral interleaving approaches can generate unwanted signal characteristics in heavily overlapped 3D‐MSI. Clinical images using the presented methods successfully demonstrate T 1 , proton density, and inversion recovery image contrasts using heavily overlapped 3D‐MSI. Conclusions Through automated management of spectral bin distributions across multiple interleaves, a variety of longitudinal magnetization contrasts can efficiently be acquired without any clinically relevant cross‐talk impact using heavily overlapped 3D‐MSI. Magn Reson Med 74:1349–1355, 2015. © 2014 Wiley Periodicals, Inc.
    Type of Medium: Online Resource
    ISSN: 0740-3194 , 1522-2594
    URL: Issue
    URL: Article
    DOI: 10.1002/mrm.v74.5
    DOI: 10.1002/mrm.25518
    Language: English
    Publisher: Wiley
    Publication Date: 2015
    detail.hit.zdb_id: 1493786-4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Ultrashort echo imaging of cyclically loaded rabbit patellar tendon
    Elsevier BV ; 2014
    In:  Journal of Biomechanics Vol. 47, No. 13 ( 2014-10), p. 3428-3432
    Details
    In: Journal of Biomechanics, Elsevier BV, Vol. 47, No. 13 ( 2014-10), p. 3428-3432
    Type of Medium: Online Resource
    ISSN: 0021-9290
    URL: Article
    DOI: 10.1016/j.jbiomech.2014.08.018
    RVK:
    WA 15000
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2014
    detail.hit.zdb_id: 1498351-5
    SSG: 12
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Diagnostic Accuracy of Zero-Echo Time MRI for the Evaluation of Cervical Neural Foraminal Stenosis
    Ovid Technologies (Wolters Kluwer Health) ; 2018
    In:  Spine Vol. 43, No. 13 ( 2018-07-1), p. 928-933
    Details
    In: Spine, Ovid Technologies (Wolters Kluwer Health), Vol. 43, No. 13 ( 2018-07-1), p. 928-933
    Type of Medium: Online Resource
    ISSN: 0362-2436 , 1528-1159
    URL: Article
    DOI: 10.1097/BRS.0000000000002462
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2018
    detail.hit.zdb_id: 2002195-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Effects of Surgical Factors on Cartilage Can Be Detected Using Quantitative Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction
    SAGE Publications ; 2017
    In:  The American Journal of Sports Medicine Vol. 45, No. 5 ( 2017-04), p. 1075-1084
    Details
    In: The American Journal of Sports Medicine, SAGE Publications, Vol. 45, No. 5 ( 2017-04), p. 1075-1084
    Abstract: Quantitative magnetic resonance (qMR) can be used to measure macromolecules in tissues and is a potential method of observing early cartilage changes in the development of posttraumatic osteoarthritis. Hypothesis/Purpose: We hypothesized that specific patient and surgical factors affecting cartilage matrix composition after anterior cruciate ligament (ACL) reconstruction (ACLR) can be detected using T1ρ and T2 relaxation times. Our purpose was to demonstrate this ability in a multicenter feasibility study. Study Design: Case series; Level of evidence, 4. Methods: A total of 54 patients who underwent ACLR underwent bilateral MRI at baseline before surgery and 6 months postoperatively. Operative findings were recorded. T1ρ and T2 relaxation times were calculated for 6 cartilage regions: the medial femur, lateral femur, medial tibia, lateral tibia, patella, and trochlea. A paired t test compared relaxation times at baseline and 6 months, univariate regression identified regions that influenced patient-reported outcome measures, and analysis of covariance was used to determine the surgical factors that resulted in elevated relaxation times at 6 months. Results: The injured knee had significantly prolonged T1ρ and T2 relaxation times in the tibiofemoral compartment at baseline and 6 months but had shorter values in the patellofemoral compartment compared with the uninjured knee. Prolonged T1ρ and T2 times at 6 months were noted for both the injured and uninjured knees. At 6 months, prolongation of T1ρ and T2 times in the tibial region was associated with lower patient-reported outcome measures. ACLR performed within 30 days of injury had significantly shorter T1ρ times in the tibial regions, and lateral meniscal tears treated with repair had significantly shorter T1ρ times than those treated with excision. Conclusion: Prolonged relaxation times in multiple regions demonstrate how the injury affects the entire joint after an ACL tear. Changes observed in the uninjured knee may be caused by increased loading during rehabilitation, especially in the patellofemoral articular cartilage and distal femur. Relaxation times in the tibial regions may be predictive of patient symptoms at 6 months. These same regions are affected by surgical timing as early as 30 days after injury, but this may partially be reflective of the severity of the preoperative injury and the choice of treatment of meniscal tears.
    Type of Medium: Online Resource
    ISSN: 0363-5465 , 1552-3365
    URL: Article
    DOI: 10.1177/0363546516677794
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
    detail.hit.zdb_id: 2063945-4
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    An Analysis of Turbulent Shear Stresses in Leakage Flow Through a Bileaflet Mechanical Prostheses
    ASME International ; 2002
    In:  Journal of Biomechanical Engineering Vol. 124, No. 2 ( 2002-04-01), p. 155-165
    Details
    In: Journal of Biomechanical Engineering, ASME International, Vol. 124, No. 2 ( 2002-04-01), p. 155-165
    Abstract: In this work, estimates of turbulence were made from pulsatile flow laser Doppler velocimetry measurements using traditional phase averaging and averaging after the removal of cyclic variation. These estimates were compared with estimates obtained from steady leakage flow LDV measurements and an analytical method. The results of these studies indicate that leakage jets which are free and planar in shape may be more unstable than other leakage jets, and that cyclic variation does not cause a gross overestimation of the Reynolds stresses at large distances from the leakage jet orifice.
    Type of Medium: Online Resource
    ISSN: 0148-0731 , 1528-8951
    URL: Article
    DOI: 10.1115/1.1448519
    Language: English
    Publisher: ASME International
    Publication Date: 2002
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...