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BACKGROUND Scan acceleration such as parallel imaging reduces scan time, but shorter scan time may reduce the signal-to-noise ratio and affect image quality. The reproducibility of longitudinal changes in the brain structure between non-accelerated and accelerated imaging by surface-based analysis is unclear. PURPOSE To determine the reproducibility of longitudinal changes in cortical thickness, measured by surface-based morphometry, between non-accelerated and accelerated structural T1 -weighted imaging in the healthy elderly and those with mild cognitive impairment (MCI) and Alzheimer's disease (AD). STUDY TYPE Retrospective. SUBJECTS Fifty healthy elderly subjects (age = 73 ± 5 years, 29 females, 21 males), 54 MCI patients (age = 71 ± 7 years, 23 females, 31 males), and 8 AD patients (age = 78 ± 6 years, 6 females, 2 males). FIELD STRENGTH/SEQUENCE 3 T, magnetization-prepared rapid gradient-echo. ASSESSMENT Longitudinal changes in cortical thickness estimated by the longitudinal stream in FreeSurfer from 2-year interval data, and visual assessment of image quality by three radiologists. STATISTICAL TESTS Intraclass correlation coefficient (ICC) and Kruskal-Wallis test. A P value

BACKGROUND Mapping of T1 and T2 relaxation times in cardiac MRI is an invaluable tool for the diagnosis and risk stratification of a wide spectrum of cardiac diseases. PURPOSE To investigate the global and regional reproducibility of native T1 and T2 mapping and to analyze the influence of demographic factors, physiological parameters, slice position, and myocardial regions on reproducibility. STUDY TYPE Prospective single-center cohort-study. POPULATION Fifty healthy volunteers (29 female, 21 male) with a mean age of 39.4 ± 13.7 years. FIELD STRENGTH/SEQUENCE Each volunteer was investigated twice at 1.5 T using a modified look-locker inversion-recovery (MOLLI) sequence (T1 mapping) and a T2-prepared steady-state free precession (SSFP) sequence (T2 mapping). ASSESSMENT Global T1 and T2 values were quantified for the entire left ventricle in three short-axis slices. Regional T1 and T2 values were measured for each myocardial segment and for myocardial segments grouped by slice position and anatomical region. STATISTICAL TESTS Test-retest reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman statistics. A P value

BACKGROUND Differentiation of benign and malignant pancreatic cystic lesions on MRI, computed tomography (CT), and endoscopic ultrasound (EUS) is critical for determining management. PURPOSE To perform a systematic review evaluating the diagnostic accuracy of MRI for diagnosing malignant pancreatic cystic lesions, and to compare the accuracy of MRI to CT and EUS. STUDY TYPE Systematic review and meta-analysis. DATA SOURCES MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched until February 2020 for studies reporting MRI accuracy for assessing pancreatic cystic lesions. FIELD STRENGTH 1.5T or 3.0T. ASSESSMENT Methodologic and outcome data were extracted by two reviewers (AU and MA, 2 years of experience each). All studies of pancreatic cystic lesions on MRI were identified. Studies with incomplete MRI technique were excluded. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. STATISTICAL TESTS Sensitivity/specificity was pooled using bivariate random-effects meta-analysis with 95% confidence intervals (95%CI). Pairwise-comparison of MRI to CT and EUS was performed. The impact of gadolinium-based contrast agents, mucinous lesions, and risk of bias were explored using meta-regression. RESULTS MRI pooled sensitivity was 76% (95%CI 67% to 84%) and specificity was 80% (95%CI 74% to 85%) for distinguishing benign and malignant lesions. MRI and CT had similar sensitivity (P = 0.822) and specificity (P = 0.096), but MRI was more specific than EUS (80% vs. 75%, P

BACKGROUND Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) can develop in patients with and without risk factors for hepatocellular carcinoma (HCC). PURPOSE To compare the clinical and magnetic resonance imaging (MRI) characteristics of cHCC-CCA in patients with and without risk factors for HCC, and to assess the influence of risk factors on patient prognosis. STUDY TYPE Retrospective. POPULATION A total of 152 patients with surgically confirmed cHCC-CCA. FIELD STRENGTH/SEQUENCE 1.5-T and 3-T/T1-weighted dual gradient-echo in- and opposed-phase, T2-weighted turbo-spin-echo, diffusion-weighted single-shot spin-echo echo-planar, and T1-weighted three-dimensional gradient-echo contrast-enhanced sequences. ASSESSMENT MRI features according to the Liver Imaging Reporting and Data System (LI-RADS) and pathologic findings based on revised classification were compared between patients with and without risk factors for HCC. Overall survival (OS) and recurrence-free survival (RFS) were also compared between the two groups, and factors associated with survival were evaluated. STATISTICAL TESTS The clinico-pathologic and MRI features of the two groups were compared using Student's t-tests, Mann-Whitney U-tests, and chi-square tests. OS and RFS were evaluated by the Kaplan-Meier method, and factors associated with survival were evaluated by Cox proportional hazard model. RESULTS cHCC-CCA in patients with risk factors were more frequently classified as LI-RADS category 4 or 5 (LR-4/5; probably or definitely HCC) (48.7%), whereas those without risk factors were more frequently classified as category M (LR-M; probably malignant, not specific for HCC) (63.6%). RFS and OS did not differ significantly according to risk factors (P = 0.63 and 0.83). Multivariable analysis showed that pathologic tumor type (hazard ratio 2.02; P

BACKGROUND Charcot-Marie-Tooth (CMT) disease is diagnosed through clinical findings and genetic testing. While there are neurophysiological tools and clinical functional scales in CMT, objective disease biomarkers that can facilitate in monitoring disease progression are limited. PURPOSE To investigate the utility of diffusion tensor imaging (DTI) in determining the microstructural integrity of sciatic and peroneal nerves and its correlation with the MRI grading of muscle atrophy severity and clinical function in CMT as determined by the CMT neuropathy score (CMTNS). STUDY TYPE Prospective case-control. SUBJECTS Nine CMT patients and nine age-matched controls. FIELD STRENGTH/SEQUENCE 3 T T1 -weighted in-/out-of phase spoiled gradient recalled echo (SPGR) and DTI sequences. ASSESSMENT Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) values for sciatic and peroneal nerves were obtained from DTI. Muscle atrophy was graded according to the Goutallier classification using in-/out-of phase SPGRs. DTI parameters and muscle atrophy grades were compared between CMT and controls, and the relationship between DTI parameters, muscle atrophy grades, and CMTNS were assessed. STATISTICAL TESTS The Wilcoxon Signed Ranks test was used to compare DTI parameters between CMT and controls. The relationship between DTI parameters, muscle atrophy grades, and CMTNS were analyzed using the Spearman correlation. Receiver operating characteristic (ROC) analyses of DTI parameters that can differentiate CMT from healthy controls were done. RESULTS There was a significant reduction in FA and increase in RD of both nerves (P

BACKGROUND Preoperative discrimination between malignant and benign sinonasal tumors is important for treatment plan selection. PURPOSE To build and validate a radiomic nomogram for preoperative discrimination between malignant and benign sinonasal tumors. STUDY TYPE Retrospective. POPULATION In all, 197 patients with histopathologically confirmed 84 benign and 113 malignant sinonasal tumors. FIELD STRENGTH/SEQUENCES Fast-spin-echo (FSE) T1 -weighted and fat-suppressed FSE T2 -weighted imaging on a 1.5T and 3.0T MRI. ASSESSMENT T1 and fat-suppressed T2 -weighted images were selected for feature extraction. The least absolute shrinkage selection operator (LASSO) algorithm was applied to establish a radiomic score. Multivariate logistic regression analysis was applied to determine independent risk factors, and the radiomic score was combined to build a radiomic nomogram. The nomogram was assessed in a training dataset (n = 138/3.0T MRI) and tested in a validation dataset (n = 59/1.5T MRI). STATISTICAL TESTS Independent t-test or Wilcoxon's test, chi-square-test, or Fisher's-test, univariate analysis, LASSO, multivariate logistic regression analysis, area under the curve (AUC), Hosmer-Lemeshow test, decision curve, and the Delong test. RESULTS In the validation dataset, the radiomic nomogram could differentiate benign from malignant sinonasal tumors with an AUC of 0.91. There was no significant difference in AUC between the combined radiomic score and radiomic nomogram (P > 0.05), and the radiomic nomogram showed a relatively higher AUC than the combined radiomic score. There was a significant difference in AUC between each two of the following models (the radiomic nomogram vs. the clinical model, all P

Background The diagnosis of sonographically indeterminate adnexal masses (AM) signifies a major challenge in clinical practice. Early detection and characterization have increased the need for accurate imaging evaluation before treatment. Purpose To assess the validity and reproducibility of the ADNEX MR Scoring system in the diagnosis of sonographically indeterminate AM. Study type A prospective multicenter study. Population In all, 531 women (mean age, 44 ± 11.2 years; range, 21-79 years) with 572 sonographically indeterminate AM. Field strength/sequence 1.5T/precontrast T1 -weighted imaging (WI) fast spin echo (FSE) (in-phase and out-of-phase, with and without fat suppression); T2 -WI FSE; diffusion-WI single-shot echo planner with b-values of 0 and 1000 s/mm2 ; and dynamic contrast-enhanced perfusion T1 -WI liver acquisition with volume acceleration (LAVA). Assessment All MRI examinations were evaluated by three radiologists, and the AM were categorized into five scores based on the ADNEX MR Scoring system. Score 1: no AM; 2: benign AM; 3: probably benign AM; 4: indeterminate AM; 5: probably malignant AM. Histopathology and imaging follow-up were used as the standard references for evaluating the validity of the ADNEX MR Scoring system for detecting ovarian malignancy. Statistical tests Four-fold table test, kappa statistics (κ), and receiver operating characteristic (ROC) curve. Results In all, 136 (23.8%) AM were malignant, and 436 (76.2%) were benign. Of the 350 AM classified as score 2, one (0.3%) was malignant; of the 62 AM classified as score 3, six (9.7%) were malignant; of the 73 AM classified as score 4, 43 (58.9%) were malignant; and of the 87 AM categorized as score 5, 86 (98.9%) were malignant. The best cutoff value for predicting malignant AM was score >3 with sensitivity and specificity of 92.9% and 94.9%, respectively. The interreader agreement of the ADNEX MR Scoring was very good (κ = 0.861). Data conclusion The current study supports the high validity and reproducibility of the ADNEX MR Scoring system for the diagnosis of sonographically indeterminate AM. Level of evidence 1 TECHNICAL EFFICACY STAGE: 2.

Background There appears to be less agreement in the identification of cancers in the transition zone (TZ), which is not as reliable as those in peripheral zone when using the Prostate Imaging Reporting and Data System (PI-RADS) version 2 (v2). In response to such shortcomings, the updated version 2.1 was introduced, which incorporated diffusion-weighted imaging (DWI) into category 2 and clarified lexicons. Purpose To compare the diagnostic performance for the detection of clinically significant TZ prostate cancers (csPCa) and interreader agreement between PI-RADS v2.1 and v2. Study type Retrospective study. Population In all, 142 patients, 201 TZ lesions. Field strength/sequence 3.0T; T2 -weighted image and DWI. Assessment Lesions were scored by three independent readers using PI-RADS v2 and v2.1. Statistical tests The sensitivity and specificity at category ≥3 were compared between v2 and v2.1 using the generalized estimating equation model. Detection rates for csPCa of upgraded and downgraded lesions in the use of PI-RADS v2.1 from v2 were assessed. Interreader agreement was assessed using κ statistics. Results PI-RADS v2.1 showed a higher sensitivity and specificity (94.5% and 60.9%) than v2 (91.8% and 56.3%) for category ≥3 lesions in the detection of csPCa, although not significantly. Of eight upgraded lesions from category 2 to 3 (2 + 1) with an incorporated DWI, 50% (4/8) were csPCa. This was significantly higher than category 2 lesions (4.4%; P = 0.003). No csPCa was detected among the 22.8% (46/201) downgraded lesions. There was a moderate interreader agreement for scores ≥3 (κ = 0.565) in v2.1, which was slightly higher than that for v2 (κ = 0.534), although not significantly. Data conclusion PI-RADS v2.1 provides moderate and comparable interreader agreement at category ≥3 than v2 in the TZ lesions. Upgraded lesions from category 2 to 3 demonstrated a higher detection rate of csPCa than category 2 lesions in v2.1. Level of evidence 4 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:577-586.

BACKGROUND Luminal water imaging (LWI), a multicomponent T2 mapping technique, has shown promise for prostate cancer (PCa) detection and characterization. PURPOSE To 1) quantify LWI parameters and apparent diffusion coefficient (ADC) in PCa and benign peripheral zone (PZ) tissues; and 2) evaluate the diagnostic performance of LWI, ADC, and PI-RADS parameters for differentiation between low- and high-grade PCa lesions. STUDY TYPE Prospective. SUBJECTS Twenty-six PCa patients undergoing prostatectomy (mean age 59 years, range 46-72 years). FIELD STRENGTH/SEQUENCE Multiparametric MRI at 3.0T, including diffusion-weighted imaging (DWI) and LWI T2 mapping. ASSESSMENT LWI parameters and ADC were quantified in index PCa lesions and benign PZ. STATISTICAL TESTS Differences in MRI parameters between PCa and benign PZ were assessed using Wilcoxon signed tests. Spearman correlation of pathological grade group (GG) with LWI parameters, ADC, and PI-RADS was evaluated. The utility of each of the parameters for differentiation between low-grade (GG ≤2) and high-grade (GG ≥3) PCa was determined by Mann-Whitney U tests and ROC analyses. RESULTS Twenty-six index lesions were analyzed (mean size 1.7 ± 0.8 cm, GG: 1 [n = 1; 4%], 2 [n = 14, 54%], 3 [n = 8, 31%], 5 [n = 3, 12%]). LWI parameters and ADC both showed high diagnostic performance for differentiation between benign PZ and PCa (highest area under the curve [AUC] for LWI parameter T2,short [AUC = 0.98, P

BACKGROUND Quantification of fat by proton density fat fraction (PDFF) measurements may be valuable for the quantification and follow-up of pathology in multicenter clinical trials and routine practice. However, many centers do not have access to specialist methods (such as chemical shift imaging) for PDFF measurement. This is a barrier to more widespread trial implementation. PURPOSE/HYPOTHESIS To determine the agreement between fat fraction (FF) measurements derived from 1) basic vendor-supplied sequences, 2) basic sequences with offline correction, and 3) specialist vendor-supplied methods. STUDY TYPE Prospective. POPULATION Two substudies with ten and five healthy volunteers. FIELD STRENGTH/SEQUENCE Site A: mDixon Quant (Philips 3T Ingenia); Site B: IDEAL and FLEX (GE 1.5T Optima MR450W); Site C: DIXON, with additional 5-echo gradient echo acquisition for offline correction (Siemens 3T Skyra); Site D: DIXON, with additional VIBE acquisitions for offline correction (Siemens 1.5T Avanto). The specialist method at site A was used as a standard to compare to the basic methods at sites B, C, and D. ASSESSMENT Regions of interest were placed on areas of subchondral bone on FF maps from the various methods in each volunteer. STATISTICAL TESTS Relationships between FF measurements from the various sites and Dixon methods were assessed using Bland-Altman analysis and linear regression. RESULTS Basic methods consisting of IDEAL, LAVA FLEX, and DIXON produced FF values that were linearly related to reference FF values (P

Background Preoperative evaluation of the consistency of pituitary macroadenomas is important for neurosurgeons to prepare the surgical plan. Purpose To evaluate the diagnostic performance of texture analysis (TA) of diffusion-weighted imaging (DWI) at a standard b-value (b = 1000 s/mm2 ) and a high b-value (b = 2000 s/mm2 ) for their ability to assess the tumor consistency of pituitary macroadenomas. Study type Retrospective. Population/subjects Fifty patients with histologically confirmed pituitary macroadenomas were classified as soft (n = 37) or hard (n = 13) types. Field strength/sequence Coronal T2 -weighted imaging (T2 WI), Readout Segmentation of Long Variable Echo-trains (RESOLVE) DWI at b = 1000 s/mm2 and b = 2000 s/mm2 were acquired with 3.0T MRI. Assessment The corresponding apparent diffusion coefficient (ADC) maps (ADC1000 and ADC2000 ) were registered to T2 WI. Regions of interest (ROIs) were manually drawn along the solid part of the tumor from the coregistered T2 WI-ADC images. The texture parameters from T2 WI, ADC1000 , and ADC2000 were acquired. Statistical tests The texture parameters were compared between the two types by using unpaired Student's t-test. Receiver operating characteristic (ROC) curves and logistic regression analyses were used to assess their diagnostic performance. Results Significant differences in TA parameters of ADC1000 and ADC2000 were observed between soft and hard types (P l 0.05 for all), whereas the TA of T2 WI resulted in no significant difference (P g 0.05 for all). TA of ADC2000 provided a superior diagnostic performance compared with that of ADC1000 (P = 0.038). A combination of mean value and entropy of ADC2000 yielded an AUC, a sensitivity, and a specificity of 0.911, 78.4% and 92.3%, respectively. Data conclusion TA of ADC values were useful for assessing the tumor consistency of pituitary macroadenomas. ADC2000 may facilitate better type discrimination. Level of evidence 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1507-1513.

BACKGROUND Altered gray matter (GM) volumes and functional connectivity (FC) happens in attention-deficit/hyperactivity disorder (ADHD) patients and the intelligence quotient (IQ) of ADHD patients is generally lower than healthy subjects, while few studies have focused on the association among the three. PURPOSE To investigate the abnormal changes of GM volumes and FC in ADHD patients compared with typically-developing control (TD-C), as well as the association between the changes and IQ. STUDY TYPE Case control. POPULATION 36 ADHD patients and 36 TD-C, aged 8-17. FIELD STRENGTH/SEQUENCE 3.0T/single shot echo planar imaging (EPI). ASSESSMENT Preprocessing of fMRI data and seed-based FC calculation using DPABI4.0, and VBM was performed by CAT12. STATISTICAL TESTS Comparison between groups of smoothed GM volumes was performed using two-sample t-test within SPM 12, age and total intracranial volume (TIV) were returned as covariates. Comparison between groups of FCs was performed using a two-sample t-test within RESTplus; age was returned as a covariate. False discovery rate (FDR)-corrected and P

CONTRACT GRANT SPONSOR Chinese Academy of Medical Sciences (CAMS) Initiative for Innovative Medicine; Contract grant number: 2017-I2M-1-001; Contract grant sponsor: Outstanding Youth Fund of Peking Union Medical College Hospital; Contract grant number: JQ201704; Contract grant sponsor: National Natural Science Foundation of China; Contract grant number: 81871512; Contract grant sponsor: National Public Welfare Basic Scientific Research Program of Chinese Academy of Medical Sciences; Contract grant numbers: 2018PT32003 and 2017PT32004. BACKGROUND Both compressed-sensing (CS) and gradient- and spin-echo (GRASE) sequences can achieve 3D magnetic resonance cholangiopancreatography (MRCP) with a single breath-hold (BH). This work hypothesized that compared with conventional navigator-triggered (NT)-MRCP, the two BH-MRCP protocols, GRASE and CS, may provide better imaging quality, especially for patients with irregular breathing. PURPOSE To evaluate and compare the image quality and diagnostic performance of three MRCP protocols. STUDY TYPE Prospective. SUBJECTS Seventy-four patients suspected to have duct-related pathologies were enrolled. FIELD STRENGTH 3.0T. SEQUENCES NT-MRCP, BH-CS-MRCP, and BH-GRASE-MRCP. ASSESSMENT Breath regularity was evaluated subjectively according to the respiratory waves. The acquisition time was compared. The pancreaticobiliary system was divided into 12 segments and evaluated on a 5-point scale. The diagnostic performance of the three MRCPs was evaluated and compared. STATISTICAL TESTS The Friedman test with a post-hoc test, receiver operating characteristic (ROC) curve analysis, McNemar test, and Kendall's W test were used. RESULTS The BH-MRCP decreased the scan time significantly (P

BACKGROUND The neural mechanism of amblyopia and its impact on the adult brain remain unclear. This hinders effective treatment for adults with this disease. PURPOSE To investigate neuroanatomical differences in cortical morphometry between amblyopic adults and healthy controls, and to explore the structural covariance of abnormal morphometric changes. STUDY TYPE Prospective. POPULATION Twenty-one amblyopic adults and 34 healthy controls. FIELD STRENGTH/SEQUENCE 3T MRI, T1 -weighted, MPRAGE sequence. ASSESSMENT All participants completed ophthalmologic exams to confirm the diagnosis of amblyopia or its absence in the healthy controls, including tests of ocular motility and dilation, fundus exam, autorefraction and synoptophore tests. Cortical volume, thickness, and surface area measurements were obtained using FreeSurfer software. STATISTICAL TESTS Statistical differences of MRI measures between amblyopic adults and healthy controls were identified using a general linear model with intracranial volume and age as covariates. Monte Carlo simulations were used to correct for multiple comparisons. The structural covariance of abnormal morphometric changes and the relationship between morphometric abnormalities and visual acuity of the amblyopic eye were examined. RESULTS Compared with healthy controls, amblyopic adults showed reduced cortical volume in left lateral occipital cortex, and decreased cortical thickness in bilateral inferior temporal gyrus and left precentral gyrus (P

BACKGROUND Growth plate injuries and disorders cause premature closure, resulting in shortened or deformed limbs. Quantitative assessment by MRI might monitor the status of the growth plate and may assist in the prediction of these deformations. PURPOSE To investigate whether the status of the growth plate can be monitored by quantitative evaluation using MRI of the noninjured region of the growth plate in a physeal injury model. STUDY TYPE Prospective, longitudinal. ANIMAL MODEL A 3.0-mm drill was used to create an injury to the central region of the right proximal tibial growth plate in 5-week-old male Japanese white rabbits (N = 18). The left tibia served as the control. FIELD STRENGTH/SEQUENCE 7.04T, T2 -weighted imaging, diffusion-weighted imaging. ASSESSMENT Eight of 18 rabbits underwent MRI, proton density-weighted imaging, and T2 -weighted and diffusion-weighted imaging. T2 and apparent diffusion coefficient (ADC) maps were generated for each image. The growth plate height and the T2 and ADC values of the noninjured region were measured. Two rabbits were sacrificed at 2, 4, 6, 8, and 10 weeks postinjury. Proximal tibial bones were evaluated using microcomputed tomography, histological, and immunohistological methods. STATISTICAL TESTS Data were compared using repeated-measures analysis of variance followed by Tukey post-hoc multiple comparison. RESULTS Growth plate height decreased at 10 weeks postinjury (P = 0.018) on the injured side. T2 values were greater at 2 weeks postinjury (P = 0.0478) and decreased at 8 and 10 weeks (P = 0.0226, P = 0.0470, respectively) on the injured side. ADC values increased at 6 weeks on the lateral side (P = 0.0304) and decreased at 8 weeks and 10 weeks postinjury (P < 0.01) on the medial and injured sides, respectively. DATA CONCLUSION Quantitative MRI can help monitor the status of the growth plate and capture its changes early. LEVEL OF EVIDENCE 1 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:133-143.