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  • 1
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2017
    In:  Scientific Reports Vol. 7, No. 1 ( 2017-12-13)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 7, No. 1 ( 2017-12-13)
    Abstract: The purpose of this study is to test the feasibility of applying a dual-input two-compartment liver perfusion model to patients with different pathologies. A total of 7 healthy subjects and 11 patients with focal liver lesions, including 6 patients with metastatic adenocarcinoma and 5 with hepatocellular carcinoma (HCC), were examined. Liver perfusion values were measured from both focal liver lesions and cirrhotic tissues (from the 5 HCC patients). Compared to results from volunteer livers, significantly higher arterial fraction, fractional volume of the interstitial space, and lower permeability-surface area product were observed for metastatic lesions, and significantly higher arterial fraction and lower vascular transit time were observed for HCCs ( P   〈  0.05). Significantly lower arterial fraction and higher vascular transit time, fractional volume of the vascular space, and fractional volume of the interstitial space were observed for metastases in comparison to HCCs ( P   〈  0.05). For cirrhotic livers, a significantly lower total perfusion, lower fractional volume of the vascular space, higher fractional volume of the interstitial space, and lower permeability-surface area product were noted in comparison to volunteer livers ( P   〈  0.05). Our findings support the possibility of using this model with 3D free-breathing acquisitions for lesion and diffuse liver disease characterization.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
    detail.hit.zdb_id: 2615211-3
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  • 2
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2020
    In:  Scientific Reports Vol. 10, No. 1 ( 2020-06-23)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 10, No. 1 ( 2020-06-23)
    Abstract: Perfusion properties can be estimated from pharmacokinetic models applied to DCE-MRI data using curve fitting algorithms; however, these suffer from drawbacks including the local minimum problem and substantial computational time. Here, a dictionary matching approach is proposed as an alternative. Curve fitting and dictionary matching were applied to simulated data using the dual-input single-compartment model with known perfusion property values and 5 in vivo DCE-MRI datasets. In simulation at SNR 60 dB, the dictionary estimate had a mean percent error of 0.4–1.0% for arterial fraction, 0.5–1.4% for distribution volume, and 0.0% for mean transit time. The curve fitting estimate had a mean percent error of 1.1–2.1% for arterial fraction, 0.5–1.3% for distribution volume, and 0.2–1.8% for mean transit time. In vivo , dictionary matching and curve fitting showed no statistically significant differences in any of the perfusion property measurements in any of the 10 ROIs between the methods. In vivo , the dictionary method performed over 140-fold faster than curve fitting, obtaining whole volume perfusion maps in just over 10 s. This study establishes the feasibility of using a dictionary matching approach as a new and faster way of estimating perfusion properties from pharmacokinetic models in DCE-MRI.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2615211-3
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  • 3
    In: Journal of Magnetic Resonance Imaging, Wiley, Vol. 50, No. 4 ( 2019-10), p. 1133-1143
    Abstract: The 3D breast magnetic resonance fingerprinting (MRF) technique enables T 1 and T 2 mapping in breast tissues. Combined repeatability and reproducibility studies on breast T 1 and T 2 relaxometry are lacking. Purpose To assess test–retest and two‐visit repeatability and interscanner reproducibility of the 3D breast MRF technique in a single‐institution setting. Study Type Prospective. Subjects Eighteen women (median age 29 years, range, 22–33 years) underwent Visit 1 scans on scanner 1. Ten of these women underwent test–retest scan repositioning after a 10‐minute interval. Thirteen women had Visit 2 scans within 7–15 days in same menstrual cycle. The remaining five women had Visit 2 scans in the same menstrual phase in next menstrual cycle. Five women were also scanned on scanner 2 at both visits for interscanner reproducibility. Field Strength/Sequence Two 3T MR scanners with the 3D breast MRF technique. Assessment T 1 and T 2 MRF maps of both breasts. Statistical Tests Mean T 1 and T 2 values for normal fibroglandular tissues were quantified at all scans. For variability, between and within‐subjects coefficients of variation (bCV and wCV, respectively) were assessed. Repeatability was assessed with Bland–Altman analysis and coefficient of repeatability (CR). Reproducibility was assessed with interscanner coefficient of variation (CoV) and Wilcoxon signed‐rank test. Results The bCV at test–retest scans was 9–12% for T 1 , 7–17% for T 2 , wCV was 〈 4% for T 1 , and 〈 7% for T 2 . For two visits in same menstrual cycle, bCV was 10–15% for T 1 , 13–17% for T 2 , wCV was 〈 7% for T 1 and 〈 5% for T 2 . For two visits in the same menstrual phase, bCV was 6–14% for T 1 , 15–18% for T 2 , wCV was 〈 7% for T 1 , and 〈 9% for T 2 . For test–retest scans, CR for T 1 and T 2 were 130 msec and 11 msec. For two visit scans, CR was 〈 290 msec for T 1 and 10–14 msec for T 2 . Interscanner CoV was 3.3–3.6% for T 1 and 5.1–6.6% for T 2 , with no differences between interscanner measurements ( P  = 1.00 for T 1 , P  = 0.344 for T 2 ). Data Conclusion 3D breast MRF measurements are repeatable across scan timings and scanners and may be useful in clinical applications in breast imaging. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1133–1143.
    Type of Medium: Online Resource
    ISSN: 1053-1807 , 1522-2586
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2019
    detail.hit.zdb_id: 1497154-9
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