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  1. Article ; Online: Diagnostic Utility of 3D Gradient-Echo MR Imaging Sequences through the Filum Compared with Spin-Echo T1 in Children with Concern for Tethered Cord.

    Rafiee, F / Mehan, W A / Rincon, S / Rohatgi, S / Rapalino, O / Buch, K

    AJNR. American journal of neuroradiology

    2023  Volume 44, Issue 3, Page(s) 323–327

    Abstract: Background and purpose: Fatty intrathecal lesions are a cause of tethered cord, and detection of these on spinal MR imaging is paramount. Conventional T1 FSE sequences are the mainstay of detecting fatty elements; however, 3D gradient-echo MR images, ... ...

    Abstract Background and purpose: Fatty intrathecal lesions are a cause of tethered cord, and detection of these on spinal MR imaging is paramount. Conventional T1 FSE sequences are the mainstay of detecting fatty elements; however, 3D gradient-echo MR images, volumetric interpolated breath-hold examination/liver acquisition with volume acceleration (VIBE/LAVA), are popular, given the increased motion resistance. We sought to evaluate the diagnostic accuracy of VIBE/LAVA compared with T1 FSE for detection of fatty intrathecal lesions.
    Materials and methods: In this retrospective, institutional review board-approved study, 479 consecutive pediatric spine MRIs obtained to evaluate cord tethering between January 2016 and April 2022 were reviewed. Inclusion criteria were patients who were 20 years of age or younger who underwent spine MRIs containing both axial T1 FSE and VIBE/LAVA sequences of the lumbar spine. The presence or absence of fatty intrathecal lesions was recorded for each sequence. If fatty intrathecal lesions were present, anterior-posterior and transverse dimensions were recorded. VIBE/LAVA and T1 FSE sequences were evaluated on 2 separate occasions (VIBE/LAVAs first followed by T1 FSE several weeks later) to minimize bias. Basic descriptive statistics compared fatty intrathecal lesion sizes on T1 FSEs and VIBE/LAVAs. Receiver operating characteristic curves were used to determine minimal fatty intrathecal lesion size detectable by VIBE/LAVA.
    Results: Sixty-six patients were included, with 22 having fatty intrathecal lesions (mean age, 7.2 years). T1 FSE sequences revealed fatty intrathecal lesions in 21/22 cases (95%); however, fatty intrathecal lesions on VIBE/LAVA were detected in 12/22 patients (55%). Mean anterior-posterior and transverse dimensions of fatty intrathecal lesions measured larger on T1 FSE compared with VIBE/LAVA sequences (5.4 × 5.0 mm versus 1.5 × 1.6 mm, respectively;
    Conclusions: While T1 3D gradient-echo MR images may have decreased the acquisition time and are more motion-resistant than conventional T1 FSE sequences, they are less sensitive and may miss small fatty intrathecal lesions.
    MeSH term(s) Humans ; Child ; Retrospective Studies ; Magnetic Resonance Imaging/methods ; Imaging, Three-Dimensional/methods ; Breath Holding ; ROC Curve
    Language English
    Publishing date 2023-02-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A7791
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Academic Performance-Based Compensation Models.

    Mehan, William A / Schaefer, Pamela W / Hirsch, Joshua A

    Journal of the American College of Radiology : JACR

    2019  Volume 16, Issue 11, Page(s) 1621–1627

    Abstract: Academic radiologists spend considerable amounts of time and effort providing nonclinical value-added services in the realms of teaching, research, and administration that are not reimbursable through traditional relative value units (RVUs) under the ... ...

    Abstract Academic radiologists spend considerable amounts of time and effort providing nonclinical value-added services in the realms of teaching, research, and administration that are not reimbursable through traditional relative value units (RVUs) under the resource-based relative value scale. Numerous systems of academic RVUs have been proposed by medicine, surgery, and radiology programs to measure and reward these nonclinical contributions. In this article the authors (1) describe the traditional clinical RVU model of reimbursement; (2) review attempts to develop academic compensation models targeted toward research, teaching, and administration; and (3) describe possible models for academic productivity compensation.
    MeSH term(s) Academic Medical Centers/organization & administration ; Academic Performance/standards ; Faculty, Medical/organization & administration ; Health Services Research/standards ; Humans ; Radiology/organization & administration ; Relative Value Scales ; United States
    Language English
    Publishing date 2019-06-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2274861-1
    ISSN 1558-349X ; 1546-1440
    ISSN (online) 1558-349X
    ISSN 1546-1440
    DOI 10.1016/j.jacr.2019.05.021
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Paraspinal Myositis in Patients with COVID-19 Infection.

    Mehan, W A / Yoon, B C / Lang, M / Li, M D / Rincon, S / Buch, K

    AJNR. American journal of neuroradiology

    2020  Volume 41, Issue 10, Page(s) 1949–1952

    Abstract: Myalgia is a previously reported symptom in patients with COVID-19 infection; however, the presence of paraspinal myositis has not been previously reported. We report MR imaging findings of the spine obtained in a cohort of 9 patients with COVID-19 ... ...

    Abstract Myalgia is a previously reported symptom in patients with COVID-19 infection; however, the presence of paraspinal myositis has not been previously reported. We report MR imaging findings of the spine obtained in a cohort of 9 patients with COVID-19 infection who presented to our hospital between March 3, 2020 and May 6, 2020. We found that 7 of 9 COVID-19 patients (78%) who underwent MR imaging of the spine had MR imaging evidence of paraspinal myositis, characterized by intramuscular edema and/or enhancement. Five of these 7 patients had a prolonged hospital course (greater than 25 days). Our knowledge of the imaging manifestations of COVID-19 infection is expanding. It is important for clinicians>a to be aware of the relatively high frequency of paraspinal myositis in this small cohort of patients with COVID-19 infection.
    MeSH term(s) Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; COVID-19 ; Coronavirus Infections/complications ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Myositis/diagnostic imaging ; Myositis/etiology ; Pandemics ; Pneumonia, Viral/complications ; SARS-CoV-2 ; Spine/diagnostic imaging
    Keywords covid19
    Language English
    Publishing date 2020-08-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A6711
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Reliable Future Climatic Projections for Sustainable Hydro-Meteorological Assessments in the Western Lake Erie Basin

    Mehan, Sushant / Flanagan, Dennis C / Gitau, Margaret W

    Water. 2019 Mar. 20, v. 11, no. 3

    2019  

    Abstract: ... and accessible through the Purdue University Research Repository (Mehan et al., 2019), which is ...

    Abstract Modeling efforts to simulate hydrologic processes under different climate conditions rely on accurate input data. Among other inaccuracies, errors in climate projections can lead to incorrect decisions. This study aimed to develop a reliable climate (precipitation and temperature) database for the Western Lake Erie Basin for the 21st century. Two statistically downscaled bias-corrected sources of climate projections (GDO: Global Downscaled Climate and Hydrology Projections and MACA: Multivariate Adaptive Constructed Analogs) were tested for their effectiveness in simulating historic climate (1966–2005) using ground-based station data from the National Climatic Data Center. MACA was found to have less bias than GDO and was better at simulating selected climate indices; thus, its climate projections were subsequently tested with different bias correction methods including the power transformation method, variance scaling of temperature, and Stochastic Weather Generators. The power transformation method outperformed the other methods and was used in bias corrections for 2006 to 2099. From the analysis, mean daily precipitation values were expected to remain more or less the same under both RCP (Representative Concentration Pathway) 4.5 and RCP 8.5 scenarios, ranging between 2.4 mm and 3.2 mm, while standard deviations were expected to increase, pointing to a rescaling of the distribution. Maximum one-day precipitation was expected to increase and could vary between 120 and 650 mm across the basin, while the number of wet days could potentially increase under the effects of RCP 4.5 and RCP 8.5. Both mean maximum and mean minimum daily air temperatures were expected to increase by up to 5.0 °C across the basin, while absolute maximum and minimum values could increase by more than 10 °C. The number of days in which precipitation could potentially fall as snow was expected to decrease, as was the annual number of days for optimal corn growth, although an earlier start to the growing season could be expected. Results from this study were very useful in creating a reliable climate database for the entire Western Lake Erie Basin (WLEB), which can be used for hydrologic, water resources, and other applications in the basin. The resulting climate database is published and accessible through the Purdue University Research Repository (Mehan et al., 2019), which is an open-access repository.
    Keywords air temperature ; basins ; climate models ; climatic factors ; corn ; databases ; growing season ; hydrometeorology ; Lepidium meyenii ; snow ; standard deviation ; university research ; variance ; water resources ; Lake Erie
    Language English
    Dates of publication 2019-0320
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2521238-2
    ISSN 2073-4441
    ISSN 2073-4441
    DOI 10.3390/w11030581
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Building the next generation of virtual cells to understand cellular biology.

    Johnson, Graham T / Agmon, Eran / Akamatsu, Matthew / Lundberg, Emma / Lyons, Blair / Ouyang, Wei / Quintero-Carmona, Omar A / Riel-Mehan, Megan / Rafelski, Susanne / Horwitz, Rick

    Biophysical journal

    2023  Volume 122, Issue 18, Page(s) 3560–3569

    Abstract: Cell science has made significant progress by focusing on understanding individual cellular processes through reductionist approaches. However, the sheer volume of knowledge collected presents challenges in integrating this information across different ... ...

    Abstract Cell science has made significant progress by focusing on understanding individual cellular processes through reductionist approaches. However, the sheer volume of knowledge collected presents challenges in integrating this information across different scales of space and time to comprehend cellular behaviors, as well as making the data and methods more accessible for the community to tackle complex biological questions. This perspective proposes the creation of next-generation virtual cells, which are dynamic 3D models that integrate information from diverse sources, including simulations, biophysical models, image-based models, and evidence-based knowledge graphs. These virtual cells would provide statistically accurate and holistic views of real cells, bridging the gap between theoretical concepts and experimental data, and facilitating productive new collaborations among researchers across related fields.
    Language English
    Publishing date 2023-04-11
    Publishing country United States
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 218078-9
    ISSN 1542-0086 ; 0006-3495
    ISSN (online) 1542-0086
    ISSN 0006-3495
    DOI 10.1016/j.bpj.2023.04.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The Hammersmith Score optimises patient selection and predicts for overall survival in early-phase cancer trial participants independent of tumour burden.

    Korolewicz, James Alexander / Scheiner, Bernhard / Fulgenzi, Claudia A M / D'Alessio, Antonio / Cortellini, Alessio / Pascual, Chynna / Mehan, Aman / Partridge, Sarah / Gujral, Dorothy M / Mohammed, Waleed / Mohammed, Oreoluwa / Grzesiak, Aneta / Booker, Lauren / Cleator, Susan / Pokrovska, Tzveta / Saleem, Waqar / Rackie, James / Needham, Yasmine / Krell, Jonathan /
    McNeish, Iain / Tookman, Laura / Park, Won-Ho Edward / Asif, Muzamil / Evans, Joanne S / Pinato, David J

    Chemotherapy

    2024  

    Abstract: Introduction: As tumour response rates are increasingly demonstrated in early-phase cancer trials (EPCT), optimal patient selection and accurate prognostication is paramount. Hammersmith Score (HS), a simple prognostic index derived on routine ... ...

    Abstract Introduction: As tumour response rates are increasingly demonstrated in early-phase cancer trials (EPCT), optimal patient selection and accurate prognostication is paramount. Hammersmith Score (HS), a simple prognostic index derived on routine biochemical measures (Albumin <35g/L, Lactate Dehydrogenase (LDH) >450 IU/L, Sodium <135mmol/L) is a validated predictor of response and survival in EPCT participants. HS has not been validated in the cancer immunotherapy era.
    Methods: We retrospectively analysed characteristics and outcomes of unselected referrals to our early-phase unit (12/2019-12/2022). Independent predictors for overall survival (OS) were identified from univariable and multivariable models. HS was calculated for 66 eligible trial participants and compared with the Royal Marsden Score (RMS) to predict OS. Multivariable logistic regression and c-index was used to compare predictive ability of prognostic models.
    Results: Of 212 referrals, 147 patients were screened and 82 patients treated in EPCT. Prognostic stratification by HS identifies significant difference in median OS and HS was confirmed as a multivariable predictor for OS (HR: HS 1 vs. 0 2.51, 95%CI: 1.01-6.24, p=0.049; HS 2/3 vs. 0: 10.32, 95%CI: 2.15-49.62, p=0.004; C-index 0.771) with superior multivariable predictive ability than RMS (HR: RMS 2 vs. 0/1 5.46, 95%CI: 1.12-26.57, p=0.036; RMS 3 vs. 0/1 6.83, 95%CI: 1.15-40.53, p<0.001; C-index 0.743).
    Conclusions: HS is a validated prognostic index for patients with advanced cancer treated in the context of modern EPCTs, independent of tumour burden. HS is a simple, inexpensive prognostic tool to optimise referral for EPCT.
    Language English
    Publishing date 2024-04-27
    Publishing country Switzerland
    Document type News
    ZDB-ID 6708-8
    ISSN 1421-9794 ; 0009-3157
    ISSN (online) 1421-9794
    ISSN 0009-3157
    DOI 10.1159/000539109
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Chest CT Scanning in Suspected Stroke: Not Always Worth the Extra Mile.

    Li, M D / Lang, M / Yoon, B C / Applewhite, B P / Buch, K / Rincon, S P / Leslie-Mazwi, T M / Mehan, W A

    AJNR. American journal of neuroradiology

    2020  Volume 41, Issue 11, Page(s) E86–E87

    MeSH term(s) Betacoronavirus ; COVID-19 ; Coronavirus Infections ; Craniocerebral Trauma ; Humans ; Pandemics ; Pneumonia, Viral ; SARS-CoV-2 ; Stroke/diagnostic imaging ; Tomography, X-Ray Computed
    Keywords covid19
    Language English
    Publishing date 2020-08-13
    Publishing country United States
    Document type Letter ; Comment
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A6763
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Risk of Acute Cerebrovascular Events in Patients with COVID-19 Infection.

    Lang, M / Li, M D / Buch, K / Yoon, B C / Applewhite, B P / Leslie-Mazwi, T M / Rincon, S / Mehan, W A

    AJNR. American journal of neuroradiology

    2020  Volume 41, Issue 11, Page(s) E92–E93

    MeSH term(s) Aged ; Betacoronavirus ; COVID-19 ; Coronavirus Infections/complications ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral/complications ; Prevalence ; SARS-CoV-2 ; Stroke/epidemiology ; Stroke/etiology
    Keywords covid19
    Language English
    Publishing date 2020-08-27
    Publishing country United States
    Document type Letter
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A6796
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Leukoencephalopathy Associated with Severe COVID-19 Infection: Sequela of Hypoxemia?

    Lang, M / Buch, K / Li, M D / Mehan, W A / Lang, A L / Leslie-Mazwi, T M / Rincon, S P

    AJNR. American journal of neuroradiology

    2020  Volume 41, Issue 9, Page(s) 1641–1645

    Abstract: There is increasing evidence to suggest that complications of coronavirus disease 2019 (COVID-19) infection are not only limited to the pulmonary system but can also involve the central nervous system. Here, we report 6 critically ill patients with COVID- ...

    Abstract There is increasing evidence to suggest that complications of coronavirus disease 2019 (COVID-19) infection are not only limited to the pulmonary system but can also involve the central nervous system. Here, we report 6 critically ill patients with COVID-19 infection and neuroimaging findings of leukoencephalopathy. While these findings are nonspecific, we postulate that they may be a delayed response to the profound hypoxemia the patients experienced due to the infection. No abnormal enhancement, hemorrhage, or perfusion abnormalities were noted on MR imaging. In addition, Severe Acute Respiratory Syndrome coronavirus 2 was not detected in the CSF collected from the 2 patients who underwent lumbar puncture. Recognition of COVID-19-related leukoencephalopathy is important for appropriate clinical management, disposition, and prognosis.
    MeSH term(s) Aged ; Betacoronavirus ; COVID-19 ; Coronavirus Infections/complications ; Critical Illness ; Disease Progression ; Female ; Humans ; Hypoxia/etiology ; Leukoencephalopathies/diagnostic imaging ; Leukoencephalopathies/etiology ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral/complications ; SARS-CoV-2 ; Tomography, X-Ray Computed
    Keywords covid19
    Language English
    Publishing date 2020-06-25
    Publishing country United States
    Document type Journal Article
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A6671
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Clinical and Neuroimaging Correlation in Patients with COVID-19.

    Yoon, B C / Buch, K / Lang, M / Applewhite, B P / Li, M D / Mehan, W A / Leslie-Mazwi, T M / Rincon, S P

    AJNR. American journal of neuroradiology

    2020  Volume 41, Issue 10, Page(s) 1791–1796

    Abstract: Background and purpose: Coronavirus disease 2019 (COVID-19) is increasingly being recognized for its multiorgan involvement, including various neurological manifestations. We examined the frequency of acute intracranial abnormalities seen on CT and/or ... ...

    Abstract Background and purpose: Coronavirus disease 2019 (COVID-19) is increasingly being recognized for its multiorgan involvement, including various neurological manifestations. We examined the frequency of acute intracranial abnormalities seen on CT and/or MR imaging in patients with COVID-19 and investigated possible associations between these findings and clinical parameters, including length of hospital stay, requirement for intubation, and development of acute kidney injury.
    Materials and methods: This was a retrospective study performed at a large academic hospital in the United States. A total of 641 patients presented to our institution between March 3, 2020, and May 6, 2020, for treatment of coronavirus disease 2019, of whom, 150 underwent CT and/or MR imaging of the brain. CT and/or MR imaging examinations were evaluated for the presence of hemorrhage, infarction, and leukoencephalopathy. The frequency of these findings was correlated with clinical variables, including body mass index, length of hospital stay, requirement for intubation, and development of acute kidney injury as documented in the electronic medical record.
    Results: Of the 150 patients, 26 (17%) had abnormal CT and/or MR imaging findings, with hemorrhage in 11 of the patients (42%), infarction in 13 of the patients (50%), and leukoencephalopathy in 7 of the patients (27%). Significant associations were seen between abnormal CT/MR imaging findings and intensive care unit admission (
    Conclusions: A spectrum of acute neuroimaging abnormalities was seen in our cohort of patients with coronavirus disease 2019, including hemorrhage, infarction, and leukoencephalopathy. Significant associations between abnormal neuroimaging studies and markers of disease severity (intensive care unit admission, intubation, and acute kidney injury) suggest that patients with severe forms of coronavirus disease 2019 may have higher rates of neuroimaging abnormalities.
    MeSH term(s) Acute Kidney Injury/epidemiology ; Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; COVID-19 ; Central Nervous System Diseases/diagnostic imaging ; Central Nervous System Diseases/etiology ; Coronavirus Infections/complications ; Female ; Humans ; Intensive Care Units ; Length of Stay ; Leukoencephalopathies ; Male ; Middle Aged ; Neuroimaging ; Pandemics ; Pneumonia, Viral/complications ; Retrospective Studies ; SARS-CoV-2 ; Young Adult
    Keywords covid19
    Language English
    Publishing date 2020-09-10
    Publishing country United States
    Document type Journal Article
    ZDB-ID 603808-6
    ISSN 1936-959X ; 0195-6108
    ISSN (online) 1936-959X
    ISSN 0195-6108
    DOI 10.3174/ajnr.A6717
    Database MEDical Literature Analysis and Retrieval System OnLINE

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