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Background: Multiparametric MRI provides complementary information for the diagnosis and management of multiple myeloma (MM). Purpose To evaluate the association of prognostic factors of MM and parameters derived from intravoxel‐incoherent motion diffusion‐weighted imaging (IVIM‐DWI) and multiecho (ME) Dixon. Study Type: Retrospective. Population: In all, 78 MM patients. Field Strength/Sequences: T1‐weighted turbo spin‐echo sequences (TSE), IVIM‐DWI, ME 3D gradient echo sequence with multistep adaptive fitting at 3T. Assessment The region of interest (ROI) on the vertebral body was independently measured on four parametric maps (Dslow, Dfast and perfusion fraction [f], and proton‐density fat‐fraction [Ff] maps) by two readers. All patients were categorized into three groups based on the International Staging System (ISS). Statistical Tests: Three groups were compared using analysis of variance (ANOVA) and post‐hoc tests with Bonferroni correction. Logistic regression analysis was performed to predict the advancement of disease (early vs. advanced). Principal component analysis (PCA) was used to find the deterministic parameters. Results: Dslow and Ff were significantly different among ISS‐1 (n = 38), ISS‐2 (n = 22), and ISS‐3 (n = 18) groups in both readers: 0.36, 0.41, and 0.58 × 10−3 mm2/s for Dslow (P < 0.05), and 46%, 30%, and 15% for Ff (P < 0.05) in reader 1; 0.34, 0.41, and 0.58 × 10−3 mm2/s for Dslow (P < 0.05), 43%, 27%, and 13.2% for Ff (P < 0.05) in reader 2, respectively. Dfast between ISS‐3 and the other groups was significantly different in one reader only: 2.03, 2.29, and 2.85 × 10−3 mm2/s (P < 0.05). There was no significant difference in f among the groups in both readers. Logistic regression by stepwise selection indicated Ff as the single most significant factor for differentiating early and advanced stages of MM with an accuracy of 76% and area under the curve (AUC) of 0.83 (P < 0.05). PCA revealed Ff, and Dslow as the deterministic parameters, with a cumulative proportion of 0.84. Data Conclusion: D slow and Ff are associated with the prognostic factor of MM. Level of Evidence 3 Technical Efficacy Stage 5. J. MAGN. RESON. IMAGING 2021;53:491–501. [ABSTRACT FROM AUTHOR]

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint's contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints' collaborative movement. [ABSTRACT FROM AUTHOR]

Purpose: To explore magnetic resonance imaging (MRI) parameters from intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI), multiecho Dixon imaging (ME-Dixon), and dynamic contrast-enhanced imaging (DCE) for differentiating focal indeterminate marrow abnormalities MATERIALS AND METHODS: Forty-two patients with 14 benign and 28 malignant focal marrow abnormalities were included. The following were independently analyzed by two readers: signal intensity (SI), contour, and margin on conventional MR images; SI on b-800 images (SIb-800 ), apparent diffusion coefficient (ADC), IVIM parameters (Dslow, Dfast , and f), fat fraction (Ff), and DCE parameters (time-to-signal intensity curve pattern, iAUC, Ktrans , kep , and ve ). The MR characteristics and parameters from benign and malignant lesions were compared with a chi-squared test and the Mann-Whitney U-test, respectively. The area under receiver operating characteristic (ROC) curves (AUC) of each sequence were also compared. Interobserver agreements were assessed with Cohen's κ, and intraclass correlation coefficient (ICC).Results: ADC, Dslow , and Ff demonstrated a significant difference between benign and malignant marrow abnormalities for both readers (P < 0.001). SIb-800 and perfusion-related parameters from IVIM-DWI and DCE were not significantly different between the two groups (P = 0.145, 0.439, and 0.337 for reader 1, P = 0.378, 0.368, and 0.343 for reader 2, respectively). The AUCs of ADC, Dslow , and Ff were significantly higher for differentiating indeterminate marrow abnormalities in both readers (P < 0.001). Interobserver agreements were substantial in SIb-800 , and ICCs were almost perfect for ADC, Dslow , f, and Ff, and substantial for iAUC, kep , Ktrans , ve , and Dfast .Conclusion: ADC, Dslow , and Ff may provide information for differentiating focal indeterminate abnormalities.Level Of Evidence: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:49-60. [ABSTRACT FROM AUTHOR]

Susceptibility-weighted imaging (SWI) is a method that uses the intrinsic nature of local magnetic fields to enhance image contrast in order to improve the visibility of various susceptibility sources and to facilitate diagnostic interpretation. It is also the precursor to the concept of the use of phase for quantitative susceptibility mapping (QSM). Nowadays, SWI has become a widely used clinical tool to image deoxyhemoglobin in veins, iron deposition in the brain, hemorrhages, microbleeds and calcification. In this article, we review the basics of SWI, including data acquisition, data reconstruction and post-processing. In particular, the source of cusp artifacts in phase images is investigated in detail and an improved multi-channel phase data combination algorithm is provided. In addition, we show a few clinical applications of SWI for the imaging of stroke, traumatic brain injury, carotid vessel wall, siderotic nodules in cirrhotic liver, prostate cancer, prostatic calcification, spinal cord injury and intervertebral disc degeneration. As the clinical applications of SWI continue to expand both in and outside the brain, the improvement of SWI in conjunction with QSM is an important future direction of this technology. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Early extubation after liver transplantation is safe and accelerates patient recovery. Patients with end-stage liver disease undergo sarcopenic changes, and sarcopenia is associated with postoperative morbidity and mortality. We investigated the impact of core muscle mass on the feasibility of immediate extubation in the operating room (OR) after living donor liver transplantation (LDLT). Methods: A total of 295 male adult LDLT patients were retrospectively reviewed between January 2011 and December 2017. In total, 40 patients were excluded due to emergency surgery or severe encephalopathy. A total of 255 male LDLT patients were analyzed in this study. According to the OR extubation criteria, the study population was classified into immediate and conventional extubation groups (39.6 vs. 60.4%). Psoas muscle area was estimated using abdominal computed tomography and normalized by height squared (psoas muscle index [PMI]). Results: There were no significant differences in OR extubation rates among the five attending transplant anesthesiologists. The preoperative PMI correlated with respiratory performance. The preoperative PMI was higher in the immediate extubation group than in the conventional extubation group. Potentially significant perioperative factors in the univariate analysis were entered into a multivariate analysis, in which preoperative PMI and intraoperative factors (i.e., continuous renal replacement therapy, significant post-reperfusion syndrome, and fresh frozen plasma transfusion) were associated with OR extubation. The duration of ventilator support and length of intensive care unit stay were shorter in the immediate extubation group than in the conventional extubation group, and the incidence of pneumonia and early allograft dysfunction were also lower in the immediate extubation group. Conclusions: Our study could improve the accuracy of predictions concerning immediate post-transplant extubation in the OR by introducing preoperative PMI into predictive models for patients who underwent elective LDLT. [ABSTRACT FROM AUTHOR]

To evaluate the intravoxel incoherent motion (IVIM) diffusion-weighted (DW) MRI for differentiating between benign and malignant musculoskeletal tumours at 3 T. 65 patients with treatment-naïve musculoskeletal tumours (47 malignant and 23 benign lesions) who underwent 3 T MRI including IVIM DW imaging were included. IVIM-derived parameters included pure diffusion coefficient (D), perfusion related incoherent microcirculation (D*, pseudodiffusion coefficient), and perfusion fraction (f). IVIM parameters and mono-exponential apparent diffusion coefficient (ADC) were retrospectively measured by two independent musculoskeletal radiologists. D and ADC values of malignant tumours (923 ± 360, 965 ± 353 µm2 s–1, respectively) were significantly lower than those of benign tumours (1668 ± 546, 1689 ± 526 µm2 s–1) (p < 0.001). F values of malignant tumours (9.6%) were significantly higher than those of benign tumours (7.2%) (p = 0.021), whereas D* values showed no significant difference (p > 0.05). The area under the receiver operating characteristic (ROC) curve of D, ADC and f were 0.874, 0.880 and 0.671, respectively. Using cut-off values of D and ADC of 1200 µm2 s–1, the sensitivity, specificity and accuracy were 92, 83, 89%, 92, 87 and 90%, respectively. D and ADC may be more accurate and reliable for differentiation of malignant from benign musculoskeletal tumours than f and D* at 3 T IVIM DW imaging. Among IVIM-derived parameters, D is more accurate and reliable in differentiating malignant from benign musculoskeletal tumours than f and D* at 3.0T IVIM DW imaging. There was no significant difference in the diagnostic performance of D and ADC. [ABSTRACT FROM AUTHOR]

Magnetic resonance neurography (MRN) is increasingly used to visualize peripheral nerves in vivo. However, the implementation and interpretation of MRN in the brachial and lumbosacral plexi are challenging because of the anatomical complexity and technical limitations. The purpose of this article was to review the clinical context of MRN, describe advanced magnetic resonance (MR) techniques for plexus imaging, and list the general categories of utility of MRN with pertinent imaging examples. The selection and optimization of MR sequences are centered on the homogeneous suppression of fat and blood vessels while enhancing the visibility of the plexus and its branches. Standard 2D fast spin-echo sequences are essential to assess morphology and signal intensity of nerves. Moreover, nerve-selective 3D isotropic images allow improved visualization of nerves and multiplanar reconstruction along their course. Diffusion-weighted and diffusion-tensor images offer microscopic and functional insights into peripheral nerves. The interpretation of MRN in the brachial and lumbosacral plexi should be based on a thorough understanding of their anatomy and pathophysiology. Anatomical landmarks assist in identifying brachial and lumbosacral plexus components of interest. Thus, understanding the varying patterns of nerve abnormalities facilitates the interpretation of aberrant findings., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2023 The Korean Society of Radiology.)

MRI is a valuable imaging technique for the evaluation of intraarticular diseases. Accurate interpretation of joint MRI necessitates sound knowledge of anatomy. In the field of joint anatomy, in addition to the discovery of new structures, previously reported joint components of unexplained function are also detected. In this review, joint anatomy researched actively over the last decade is discussed. Joint components including the rotator cable and the superior capsule of the shoulder, posterolateral corner and the anterolateral ligament complex of the knee, and the distal tibiofibular syndesmosis of the ankle joint are introduced and correlated with their MRI features., Competing Interests: Conflicts of Interest: The authors have no potential conflicts of interest to disclose., (Copyrights © 2020 The Korean Society of Radiology.)