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  • 1
    In: Skeletal Radiology, Springer Science and Business Media LLC, Vol. 46, No. 1 ( 2017-1), p. 7-15
    Type of Medium: Online Resource
    ISSN: 0364-2348 , 1432-2161
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
    detail.hit.zdb_id: 1461957-X
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  • 2
    In: European Radiology, Springer Science and Business Media LLC, Vol. 29, No. 2 ( 2019-2), p. 609-619
    Type of Medium: Online Resource
    ISSN: 0938-7994 , 1432-1084
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2019
    detail.hit.zdb_id: 1472718-3
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  • 3
    In: European Radiology, Springer Science and Business Media LLC, Vol. 32, No. 2 ( 2022-02), p. 1276-1284
    Abstract: Vessel wall enhancement (VWE) may be commonly seen on MRI images of asymptomatic subjects. This study aimed to characterize the VWE of the proximal internal carotid (ICA) and vertebral arteries (VA) in a non-vasculitic elderly patient cohort. Methods Cranial MRI scans at 3 Tesla were performed in 43 patients (aged ≥ 50 years) with known malignancy for exclusion of cerebral metastases. For vessel wall imaging (VWI), a high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo sequence (T1 CS-SPACE prototype) was applied post gadolinium with an isotropic resolution of 0.55 mm. Bilateral proximal intradural ICA and VA segments were evaluated for presence, morphology, and longitudinal extension of VWE. Results Concentric VWE of the proximal intradural ICA was found in 13 (30%) patients, and of the proximal intradural VA in 39 (91%) patients. Mean longitudinal extension of VWE after dural entry was 13 mm in the VA and 2 mm in the ICA. In 14 of 39 patients (36%) with proximal intradural VWE, morphology of VWE was suggestive of the mere presence of vasa vasorum. In 25 patients (64 %), morphology indicated atherosclerotic lesions in addition to vasa vasorum. Conclusions Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in elderly subjects. Concentric VWE in these locations should not be confused with large artery vasculitis. Distal to these segments, VWE may be more likely related to pathologic conditions such as vasculitis. Key Points • Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in non-vasculitic elderly people. • Concentric enhancement within the proximal 2 mm of the intradural ICA and within the proximal 13 mm of the intradural VA portions should not be misinterpreted as vasculitis. • Distal of this, VWE is likely related to pathologic conditions, in case of concentric VWE suggestive of vasculitis.
    Type of Medium: Online Resource
    ISSN: 0938-7994 , 1432-1084
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 1472718-3
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  • 4
    Online Resource
    Online Resource
    Ovid Technologies (Wolters Kluwer Health) ; 2016
    In:  Investigative Radiology Vol. 51, No. 10 ( 2016-10), p. 609-617
    In: Investigative Radiology, Ovid Technologies (Wolters Kluwer Health), Vol. 51, No. 10 ( 2016-10), p. 609-617
    Abstract: The aim of this study was to prospectively test the hypothesis that a 2-dimensional (2D) CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) sampling pattern facilitates 5-minute high spatial resolution 3-dimensional (3D) sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) magnetic resonance imaging (MRI) of the knee with image quality similar or better than current 2D turbo spin echo (TSE) and 3D SPACE standards. Materials and Methods The study was approved by our institutional review board. Twenty asymptomatic subjects (12 men, 8 women; mean age, 42 years; age range, 24–65 years) underwent 3 T MRI of the knee. A 4-fold accelerated 3D SPACE TSE prototype with 2D CAIPIRINHA sampling pattern and 5-minute acquisition time was compared with commercially available 2-fold and 4-fold accelerated 3D SPACE and 2D TSE pulse sequences with acquisition times of 11 minutes and 15 seconds, 6 minutes and 30 seconds, as well as 9 minutes and 48 seconds, respectively. Outcome variables included image quality, anatomic visibility, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Statistical analysis included Friedman, repeated measures analysis of variances, and Cohen's weighted κ tests. Bonferroni-corrected P values of 0.005 and less were considered statistically significant. Results Overall, image quality, visibility of anatomic structures, SNR, and CNR of 3D CAIPIRINHA SPACE were statistically similar to 2-fold accelerated 3D SPACE and significantly better than 4-fold accelerated 3D SPACE, which exhibited degrading parallel imaging artifacts. Compared with 2.5-mm 2D TSE images, 0.5-mm 3D CAIPIRINHA SPACE images showed statistically similar good edge sharpness and very good contrast resolution, and significantly less partial volume as well as absent chemical shift and pulsatile flow artifacts. Visibility of menisci, anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, and lateral collateral ligament was good to very good on 0.5-mm 3D CAIPIRINHA SPACE images as compared with good on 2.5-mm 2D TSE image ( P 〈 0.005). The SNR of fat, fluid, and cartilage as well as CNR between cartilage, fluid, fat, posterior cruciate ligament, and menisci were minimally higher on 2.5-mm 2D TSE image ( P 〈 0.005). Image quality, visibility of anatomic structures, SNR, and CNR of 2.5-mm 3D CAIPIRINHA SPACE and 2.5-mm 2D TSE images were good to very good without significant differences. Conclusions Three-dimensional SPACE with 2D CAIPIRINHA sampling pattern enables high-quality 3D TSE MRI of the knee at an acquisition time of 5 minutes and image quality, visibility of anatomic structures, SNR, and CNR similar to conventional 3D SPACE and 2D TSE, both of which require approximately 10-minute acquisition times.
    Type of Medium: Online Resource
    ISSN: 1536-0210 , 0020-9996
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2016
    detail.hit.zdb_id: 2041543-6
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  • 5
    In: Investigative Radiology, Ovid Technologies (Wolters Kluwer Health), Vol. 53, No. 12 ( 2018-12), p. 742-747
    Abstract: High-resolution T2-weighted sequences are frequently used in magnetic resonance imaging (MRI) studies to assess the cerebellopontine angle and internal auditory canal (IAC) in sensorineural hearing loss patients but have low yield and lengthened examinations. Because image content in the Wavelet domain is sparse, compressed sensing (CS) that uses incoherent undersampling of k -space and iterative reconstruction can accelerate MRI acquisitions. We hypothesized that an accelerated CS T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) sequence would produce acceptable diagnostic quality for IAC screening protocols. Material and Methods Seventy-six patients underwent 3 T MRI using conventional SPACE and a CS T2 SPACE prototype sequence for screening the IACs were identified retrospectively. Unilateral reconstructions for each sequence were separated, then placed into mixed folders for independent, blinded review by 3 neuroradiologists during 2 sessions 4 + weeks apart. Radiologists reported if a lesion was present. Motion and visualization of specific structures were rated using ordinal scales. McNemar, Wilcoxon, Cohen κ, and Mann-Whitney U tests were performed for accuracy, equivalence, and interrater and intrarater reliability. Results T2 SPACE using CS reconstruction reduced scan time by 80% to 50 seconds and provided 98.7% accuracy for IAC mass detection by 3 raters. Radiologists preferred conventional images (0.7–1.0 reduction on 5-point scale, P 〈 0.001), but rated CS SPACE acceptable. The 95% confidence for reduction in any cerebellopontine angle, IAC, or fluid-filled inner ear structure assessment with CS SPACE did not exceed 0.5. Conclusions Internal auditory canal screening MRI protocols can be performed using a 5-fold accelerated T2 SPACE sequence with compressed sensing while preserving diagnostic image quality and acceptable lesion detection rate.
    Type of Medium: Online Resource
    ISSN: 1536-0210 , 0020-9996
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2018
    detail.hit.zdb_id: 2041543-6
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  • 6
    In: Investigative Radiology, Ovid Technologies (Wolters Kluwer Health), Vol. 58, No. 6 ( 2023-6), p. 405-412
    Abstract: Detection of rotator cuff tears, a common cause of shoulder disability, can be time-consuming and subject to reader variability. Deep learning (DL) has the potential to increase radiologist accuracy and consistency. Purpose The aim of this study was to develop a prototype DL model for detection and classification of rotator cuff tears on shoulder magnetic resonance imaging into no tear, partial-thickness tear, or full-thickness tear. Materials and Methods This Health Insurance Portability and Accountability Act-compliant, institutional review board–approved study included a total of 11,925 noncontrast shoulder magnetic resonance imaging scans from 2 institutions, with 11,405 for development and 520 dedicated for final testing. A DL ensemble algorithm was developed that used 4 series as input from each examination: fluid-sensitive sequences in 3 planes and a sagittal oblique T1-weighted sequence. Radiology reports served as ground truth for training with categories of no tear, partial tear, or full-thickness tear. A multireader study was conducted for the test set ground truth, which was determined by the majority vote of 3 readers per case. The ensemble comprised 4 parallel 3D ResNet50 convolutional neural network architectures trained via transfer learning and then adapted to the targeted domain. The final tear-type prediction was determined as the class with the highest probability, after averaging the class probabilities of the 4 individual models. Results The AUC overall for supraspinatus, infraspinatus, and subscapularis tendon tears was 0.93, 0.89, and 0.90, respectively. The model performed best for full-thickness supraspinatus, infraspinatus, and subscapularis tears with AUCs of 0.98, 0.99, and 0.95, respectively. Multisequence input demonstrated higher AUCs than single-sequence input for infraspinatus and subscapularis tendon tears, whereas coronal oblique fluid-sensitive and multisequence input showed similar AUCs for supraspinatus tendon tears. Model accuracy for tear types and overall accuracy were similar to that of the clinical readers. Conclusions Deep learning diagnosis of rotator cuff tears is feasible with excellent diagnostic performance, particularly for full-thickness tears, with model accuracy similar to subspecialty-trained musculoskeletal radiologists.
    Type of Medium: Online Resource
    ISSN: 1536-0210 , 0020-9996
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2023
    detail.hit.zdb_id: 2041543-6
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  • 7
    In: Journal of Cachexia, Sarcopenia and Muscle, Wiley, Vol. 9, No. 6 ( 2018-12), p. 1093-1100
    Abstract: Changes in muscle fat composition as for example observed in sarcopenia or muscular dystrophy affect physical performance and muscular function, like strength and power. The purpose of the present study is to measure the repeatability of Dixon magnetic resonance imaging (MRI) for assessing muscle volume and fat in the thigh. Furthermore, repeatability of magnetic resonance spectroscopy (MRS) for assessing muscle fat is determined. Methods A prototype 6‐point Dixon MRI method was used to measure muscle volume and muscle proton density fat fraction (PDFF) in the left thigh. PDFF was measured in musculus semitendinosus of the left thigh with a T2‐corrected multi‐echo MRS method. For the determination of short‐term repeatability (consecutive examinations), the root mean square coefficients of variation of Dixon MRI and MRS data of 23 young and healthy (29 ± 5 years) and 24 elderly men with sarcopenia (78 ± 5 years) were calculated. For the estimation of the long‐term repeatability (13 weeks between examinations), the root mean square coefficients of variation of MRI data of seven young and healthy (31 ± 7 years) and 23 elderly sarcopenic men (76 ± 5 years) were calculated. Long‐term repeatability of MRS was not determined. Results Short‐term errors of Dixon MRI volume measurement were between 1.2% and 1.5%, between 2.1% and 1.6% for Dixon MRI PDFF measurement, and between 9.0% and 15.3% for MRS. Because of the high short‐term repeatability errors of MRS, long‐term errors were not determined. Long‐term errors of MRI volume measurement were between 1.9% and 4.0% and of Dixon MRI PDFF measurement between 2.1% and 4.2%. Conclusions The high degree of repeatability of volume and PDFF Dixon MRI supports its use to predict future mobility impairment and measures the success of therapeutic interventions, for example, in sarcopenia in aging populations and muscular dystrophy. Because of possible inhomogeneity of fat infiltration in muscle tissue, the application of MRS for PDFF measurements in muscle is more problematic because this may result in high repeatability errors. In addition, the tissue composition within the MRS voxel may not be representative for the whole muscle.
    Type of Medium: Online Resource
    ISSN: 2190-5991 , 2190-6009
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2018
    detail.hit.zdb_id: 2586864-0
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  • 8
    In: Clinical Neuroradiology, Springer Science and Business Media LLC, Vol. 31, No. 1 ( 2021-03), p. 207-216
    Type of Medium: Online Resource
    ISSN: 1869-1439 , 1869-1447
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2232347-8
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  • 9
    Online Resource
    Online Resource
    SAGE Publications ; 2019
    In:  Orthopaedic Journal of Sports Medicine Vol. 7, No. 3_suppl ( 2019-03-01), p. 2325967119S0013-
    In: Orthopaedic Journal of Sports Medicine, SAGE Publications, Vol. 7, No. 3_suppl ( 2019-03-01), p. 2325967119S0013-
    Abstract: Magnetic resonance imaging (MRI) is often indicated in the diagnosis of pediatric knee trauma, but using traditional MRIs in children can be time-consuming, require anaesthesia, and sometimes cause discomfort. Recently, 3D turbo spin echo (TSE) MRIs with isotropic datasets have been found to reduce acquisition times substantially, but they have been little-studied in pediatric patients. The purpose of our study was to determine the arthroscopy-based diagnostic performance of 10-minute isotropic 3D TSE MRI for the detection of internal derangement in children with acute knee trauma. Methods Institutional review board approval was obtained for prospective data collection, and informed consent and assent were obtained from all parents and children, respectively. The final study group consisted of 60 children (38 boys, 22 girls; 11 (2-16) years-of-age) with acute knee trauma who underwent 10-minute isotropic 3D prototype CAIPIRINHA SPACE MRI at 3 T and subsequent arthroscopic knee surgery. Two fellowship-trained musculoskeletal radiologists retrospectively evaluated the MRI studies independently and resolved discrepancies through consensus. Outcome variables included image quality, motion artifacts, meniscal abnormalities, cruciate ligament tears, and cartilage lesions. Statistical analysis included the diagnostic performance of MRI with arthroscopy as the reference standard and inter-reader agreements using kappa statistics. Results All studies were suitable for diagnostic interpretation with good-to-very-good image quality and little-to-no motion degradation in the majority of cases. The sensitivities/specificities/accuracies of MRI were 0.93/0.93/0.93 for 15/60 (25%) medial meniscal tears, 0.95/0.90/0.92 for 21/60 (35%) lateral meniscal tears, 0.83/1.0/0.92 for 10/60 (17%) discoid menisci, 1.0/0.95/0.98 for 16/60 (27%) anterior cruciate ligament tears, 1.0/0.95/0.98 for 2/60 (3%) posterior cruciate ligament tears, 1.0/1.0/1.0 for 5/60 (8%) osteochondritis dissecans lesions, and 0.71/0.97/0.84 for 48 (13%) defects in 360 cartilage segments. The inter-reader agreements were overall good-to-very-good (kappa, 0.730 -1.00). Conclusion 10-minute isotropic 3D TSE MRI of the knee is feasible in children with acute knee trauma and yields high diagnostic accuracies for the diagnosis of internal knee derangement. Accuracies for the detection of meniscal tears, discoid menisci, anterior and posterior cruciate ligament tears, osteochondritis dissecans lesions, and cartilage defects ranged from 84-100%. Using previously published protocols for pediatric 2D MRI knee exams with total acquisition times of 25 minutes as a benchmark for traditional MRI, a 10-minute protocol could increase the efficiency by a factor of two or more, and thus substantially improve the availability of MRI and timely care for children with acute knee trauma. [Table: see text]
    Type of Medium: Online Resource
    ISSN: 2325-9671 , 2325-9671
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2019
    detail.hit.zdb_id: 2706251-X
    SSG: 31
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  • 10
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2015
    In:  Magnetic Resonance Materials in Physics, Biology and Medicine Vol. 28, No. 5 ( 2015-10), p. 413-425
    In: Magnetic Resonance Materials in Physics, Biology and Medicine, Springer Science and Business Media LLC, Vol. 28, No. 5 ( 2015-10), p. 413-425
    Type of Medium: Online Resource
    ISSN: 0968-5243 , 1352-8661
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2015
    detail.hit.zdb_id: 1502491-X
    SSG: 11
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