Multi-sequence MRI-based radiomics: An objective method to diagnose early-stage osteonecrosis of the femoral head.

OBJECTIVES: This study investigated the use of radiomics for diagnosing early-stage osteonecrosis of the femoral head (ONFH) by extracting features from multiple MRI sequences and constructing predictive models. MATERIALS AND METHODS: We conducted a retrospective review, collected MR images of early-stage ONFH (102 from institution A and 20 from institution B) and healthy femoral heads (102 from institution A and 20 from institution B) from two institutions. We extracted radiomics features, handled batch effects using Combat, and normalized features using z-score. We employed the Least absolute shrinkage and selection operator (LASSO) algorithm, along with Max-Relevance and Min-Redundancy (mRMR), to select optimal features for constructing radiomics models based on single, double, and multi-sequence MRI data. We evaluated performance using receiver operating characteristic (ROC) and precision-recall (PR) curves, and compared area under curve of ROC (AUC-ROC) values with the DeLong test. Additionally, we studied the diagnostic performance of the multi-sequence radiomics model and radiologists, compared the diagnostic outcomes of the model and radiologists using the Fisher exact test. RESULTS: We studied 122 early-stage ONFH and 122 normal femoral heads. The multi-sequence model exhibited the best diagnostic performance among all models (AUC-ROC, PR-AUC for training set: 0.96, 0.961; validation set: 0.96, 0.97; test set: 0.94, 0.94), and it outperformed three resident radiologists on the external testing group with an accuracy of 87.5 %, sensitivity of 85.00 %, and specificity of 90.00 % (p < 0.01), highlighting the robustness of our findings. CONCLUSIONS: Our study underscored the novelty of the multi-sequence radiomics model in diagnosing early-stage ONFH. By leveraging features extracted from multiple imaging sequences, this approach demonstrated high efficacy, indicating its potential to advance early diagnosis for ONFH. These findings provided important guidance for enhancing early diagnosis of ONFH through radiomics methods, offering new avenues and possibilities for clinical practice and patient care.

Causal effects of body mass index, education, and lifestyle behaviors on intervertebral disc disorders: Mendelian randomization study.

This study aimed to investigate the causal risk factors for intervertebral disc disorders (IVDD) to help establish prevention strategies for IVDD-related diseases. We performed two-sample Mendelian randomization analyses to investigate the causal effects of body mass index (BMI), education, and lifestyle behaviors (sedentary behavior, smoking, and sleeping) on thoracic/thoracolumbar/lumbosacral IVDD (TTL-IVDD) and cervical IVDD. The inverse-variance weighted (IVW) method was conducted as the primary model to pool effect sizes using odds ratio and 95% confidence interval. The strength of causal evidence was evaluated from the effect size and different Mendelian randomization methods (MR-Egger/weighted median/weighted mode method, Cochran's Q test, leave-one-out analysis, MR Steiger, MR-PRESSO and radial IVW analyses). We found strong evidence for the causal associations between IVDD and BMI (TTL-IVDD, 1.27 [1.18, 1.37], p = 2.40 × 10-10 ; cervical IVDD, 1.24 [1.12, 1.37, p = 6.58 × 10-5 ), educational attainment (TTL-IVDD, 0.57 [0.51, 0.64], p = 9.64 × 10-21 ; cervical IVDD, 0.58 [0.49, 0.68], p = 1.78 × 10-10 ), leisure television watching (TTL-IVDD, 1.54 [1.29, 1.84], p = 7.80 × 10-6 ; cervical IVDD, 1.65 [1.29, 2.11], p = 0.0001), smoking initiation (TTL-IVDD, 1.37 [1.25, 1.50], p = 1.78 × 10-10 ; cervical IVDD, 1.32 [1.16, 1.51], p = 6.49 × 10-5 ), short sleep (TTL-IVDD, 1.28 [1.09, 1.49], p = 0.0027; cervical IVDD, 1.53 [1.21, 1.94], p = 0.0008), or frequent insomnia (TTL-IVDD, 1.20 [1.11, 1.30], p = 1.54 × 10-5 ; cervical IVDD, 1.37 [1.20, 1.57], p = 7.80 × 10-6 ). This study provided genetic evidence that increased BMI, low educational attainment, sedentary behavior by leisure television watching, smoking initiation, short sleep, and frequent insomnia were causal risk factors for IVDD. More efforts should be directed toward increasing public awareness of these modifiable risk factors and mobilizing individuals to adopt healthy lifestyles.

Gastrointestinal tumor-related perihepatic fluorouracil encapsulated lesions and liver metastases: a diagnostic imaging study based on contrast-enhanced computed tomography and magnetic resonance imaging.

Background: Perihepatic fluorouracil encapsulated lesions (FELs) can result in potentially confusing computed tomography (CT) and magnetic resonance imaging (MRI) features in postoperative examinations of gastrointestinal tumors. This retrospective study aimed to summarize the typical imaging features of FELs and determine the best imaging modality to distinguish FELs from liver metastases for junior residents. Methods: Patients with FELs who had undergone gastrointestinal tumor surgery in Tongji Hospital from January 2016 to June 2022 were evaluated. The imaging features of FELs were summarized by two senior radiologists. Contrast-enhanced CT (CECT) was used as the primary follow-up tool for postoperative gastrointestinal tumor patients. Patients with FELs and available CECT and MRI examinations were matched with patients with liver metastases based on gender and age and presented in chronological order in a 2:1 ratio. Different imaging modality combinations were used for further evaluation, including a CECT group (modality Ⅰ), CECT and nonenhanced MRI group (modality Ⅱ) and CECT with all MRI sequences group (modality Ⅲ). Subsequently, two junior residents blindly evaluated three groups following a 4-week interval based on a 5-point scale (1= definite benign lesion, 2= probable benign lesion, 3= indeterminate, 4= probable liver metastasis, 5= definite liver metastasis). Results: Imaging features of 33 patients with 36 FELs were analyzed. CECT and dynamic contrast-enhanced MRI (DCE-MRI) showed no enhancement in most lesions. Additionally, 20 patients with FELs meeting the requirements were matched with 40 patients with liver metastases. The highest sensitivity, specificity, and consistency for identifying liver metastases were achieved using a combination of CECT and MRI encompassing all sequences yielded, including modality Ⅰ (reader 1: 72.0% and 17.4%; reader 2: 62.0% and 17.4%; kappa value 0.295), modality Ⅱ (reader 1: 88.0% and 8.7%; reader 2: 92.0% and 34.8%; kappa value 0.259), and modality Ⅲ (reader 1: 98.0% and 34.8%; reader 2: 92.0% and 39.1%; kappa value 0.680). Conclusions: FELs are typically non-enhancing lesions. In our study, two junior residents could best distinguish FELs from liver metastases using CECT with all MRI sequences.

Whole-joint histogram analysis of different models of diffusion weighted imaging in evaluating disease activity of axial spondyloarthritis.

OBJECTIVES: To assess whole-joint histogram analysis of mono-exponential and bi-exponential diffusion weighted and diffusion kurtosis imaging in evaluating disease activity of axial spondyloarthritis (axSpA). METHODS: A total of 82 patients with axSpA who underwent both DKI and multi b diffusion weighted imaging of the sacroiliac joints were divided into active and inactive disease groups based on clinical activity indices. Another 17 patients with nonspecific low back pain were included as a control group. The SPARCC scoring system was used to assess the level of sacroiliac joint bone marrow edema. Histogram parameters of apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion fraction (f), pseudodiffusion coefficient (D*), mean kurtosis (MK), and mean diffusivity (MD) were calculated. Regions of interest were placed covering the entire sacroiliac joint. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of imaging parameters in distinguishing different groups. Regression analysis was applied to determine the correlation between imaging parameters and clinical activity indices. RESULTS: All of the histogram parameters distinguished the active from inactive groups with a low area under the curve (AUC) (max AUCs≤0.71), while the SPARCC score failed to differentiate the two groups (p = 0.08). MD, MK, D, D*, and ADC showed good performance in differentiating active and inactive from control groups (max AUC = 0. 81 ~ 0.98). f50 differentiated the active from control groups with an AUC of 0.72, significantly lower than the maximum AUC for MD, MK, D, ADC, and SPARCC score (all p < 0.05). The max AUC of MD in differentiating inactive from control groups was significantly higher than that of D* and the SPARCC score. MD, D, D*, f, and ADC were positively correlated with BASDAI, while MK was negatively correlated with BASDAI. Only MD was positively correlated with hsCRP. CONCLUSIONS: Whole-joint histogram analysis of mono-exponential, bi-exponential diffusion weighted, and diffusion kurtosis imaging showed good diagnostic performance in differentiating active and inactive axSpA from patients with non-specific back pain. All the imaging parameters were correlated with BASDAI except for SPARCC score. Only DKI-derived MD was correlated with an increase in hsCRP, suggesting its potential use as an imaging biomarker for disease activity in axSpA. ADVANCES IN KNOWLEDGE: 1. No significant difference was found between the three models of diffusion weighted imaging in evaluating disease activity of axial spondyloarthritis.2. Only DKI-derived MD was correlated with an increase in hsCRP, suggesting its potential use as an imaging biomarker for disease activity in axSpA.

Determinants of diurnal variation in lumbar intervertebral discs and paraspinal muscles: A prospective quantitative magnetic resonance imaging study.

PURPOSE: To prospectively investigate the determinants of diurnal variations in lumbar intervertebral discs and paraspinal muscles. METHOD: 71 females aged 19 âˆ¼ 31 years were examined by morning-evening T2 mapping/diffusion kurtosis imaging (DKI), with weight and lifestyle information (time in night bed-rest [TIB], bed-napping, activity time, and sitting time) assessed by standardized questionnaires. Diurnal shifts in T2, mean diffusivity and mean kurtosis (T2-DS, MD-DS and MK-DS; morning-value minus evening-value) were evaluated for L4-S1 discs (normal, Pfirrmann grade Ⅰ/Ⅱ; degenerative, III/IV). T2 and T2-DS were assessed for L4/5 multifidus and erector spinalis. RESULTS: For normal discs, bed-napping correlated with MD-DS and MK-DS in disc entirety (p = 0.001 and 0.004); increased activity time suggested higher T2-DS in nucleus pulposus (p = 0.004); prolonged sitting time predicted greater T2-DS in disc entirety and posterior inner annulus fibrosus (PI-AF, p ≤ 0.011); decreased TIB and weight suggested lower T2-DS and higher MK-DS in PI-AF (p = 0.001 âˆ¼ 0.035). For degenerative discs, bed-napping predicted lower T2-DS in nucleus pulposus and PI-AF (p = 0.019); increased TIBsuggested higher T2-DS and lower MK-DS in PI-AF (p = 0.006 and 0.034); longer sitting time predicted higher MK-DS in PI-AF (p = 0.020). Paraspinal muscles exhibited diurnal T2 variation (p < 0.001) which did not correlate with lifestyle factors (p > 0.050). CONCLUSIONS: Lifestyle and weight have causal effects on the diurnal variation of lumbar discs. Bed-rest may correlate with disc hydration and microstructural stability reserves for subsequent daytime activities. Sitting behavior could induce greater dehydration in normal discs and may alleviate diurnal microstructural rearrangement in degenerative discs. T2 mapping and DKI are promising tools to evaluate disc biomechanics in clinics.

Detection of erosions and fat metaplasia of the sacroiliac joints in patients with suspected sacroiliitis using a chemical shift-encoded sequence (IDEAL-IQ).

PURPOSE: To evaluate the performance of a chemical shift-encoded sequence called IDEAL-IQ for detecting sacroiliac joint (SIJ) erosions and fat metaplasia compared to T1-weighted fast spin echo (T1 FSE) using qualitative and quantitative analysis. METHOD: Thirty-four patients with suspicion of sacroiliitis who underwent both MRI and CT were included. Each SIJ was divided into four quadrants for analysis. For qualitative analysis, the diagnostic performance of IDEAL-IQ and T1 FSE for erosions were compared by the McNemar test, using CT as the gold standard. Cochran's Q and McNemar tests were used to determine differences in structural changes detected by different imaging methods. For quantitative analysis, two-sample t test and receiver operating characteristic (ROC) analysis were used for the analysis of histogram parameters of proton density fat fraction (PDFF). RESULTS: Diagnostic sensitivity and accuracy of IDEAL-IQ were greater than T1 FSE for erosions (all P < 0.05). IDEAL-IQ and CT detected more erosions than T1 FSE (all P < 0.05). IDEAL-IQ did not statistically significantly differ from T1 FSE for the detection of fat metaplasia (P = 0.678). All histogram parameters were different between groups with and without fat metaplasia (all P < 0.05) and could distinguish the two groups (all P < 0.05). PDFF75th was the most effective histogram parameter. CONCLUSION: IDEAL-IQ detects SIJ erosions with better accuracy than T1 FSE and is similar to T1 FSE for detection of fat metaplasia, enabling further quantitative analysis of the latter via histogram analysis.

Diurnal Variation in Hydration of the Cervical Intervertebral Disc Assessed Using T2 Mapping of Magnetic Resonance Imaging.

OBJECTIVE: The study aimed to investigate the diurnal variation in cervical disc hydration and its relationship with cervical degeneration. MATERIALS AND METHODS: C3-C7 discs of 86 prospectively enrolled participants (37 males, 49 females; mean age ± standard deviation, 23.5 ± 2.5 years) were assessed using T2 mapping in the morning and evening. All discs were stratified by Miyazaki grade or C2-C7 Cobb angle and T2 values (T2). The degree of diurnal T2 variation (T2-DDV), defined as (morning T2 - evening T2)/morning T2 × 100%, was measured for the entire disc, annulus fibrosus (AF), nucleus pulposus (NP), and endplate zones. RESULTS: T2 of the entire disc decreased significantly after the daytime load (p < 0.001), with a T2-DDV of 13.3% for all discs and 16.0%, 12.2%, and 13.0% for healthy (grade I), mild degenerative (grade II), and advanced degenerative (grade III/IV) discs, respectively. T2 of regional NPs and AFs decreased significantly from morning to evening (p ≤ 0.049) except in the healthy anterior inner AF (p = 0.092). Compared with healthy discs, mild degenerative discs displayed lower T2 and T2-DDV in regional NPs (p < 0.001). Advanced degenerative discs showed higher T2-DDV in the anterior inner AF compared with healthy discs (p = 0.050). Significant diurnal T2 changes in the endplate zones were observed only in healthy discs (p = 0.013). Cervical discs in the low Cobb angle group showed higher T2-DDV in the anterior AFs and anterior NP and lower T2-DDV in the posterior AF than those in the high Cobb angle group (p ≤ 0.041). CONCLUSION: This study characterized the diurnal variation in hydration of the cervical discs as assessed using T2 mapping and revealed early chemo-mechanical coupling dysfunction in degenerating discs. Cervical sagittal alignment on MRI can affect the diurnal stress patterns of the cervical discs. T2 mapping is sensitive to disc biomechanical dysfunction and offers translational potential from biomechanical research to clinical application.

Incidence of pulmonary embolism and impact on mortality in patients with malignant melanoma.

PURPOSE: Pulmonary embolism (PE) occurs frequently in patients with malignant melanoma (MM). The aim of this study is to determine the incidence of PE in patients with MM and to assess the clinical characteristics and mortality of MM patients with PE. MATERIAL AND METHODS: Medical records from 381 MM patients who underwent contrast-enhanced computed tomography were evaluated. Imaging parameters including location of PE and measurements of right heart dysfunction and clinical parameters including D-Dimer levels, local and distant tumor stage and time of death were analyzed. RESULTS: PE was found in 23/381 (6%) MM patients, whereby 17/23 (74%) were detected incidentally and only 6/23 (26%) were symptomatic. The presence of PE significantly correlated with elevated D-Dimers (p < 0.001), right ventricular dysfunction (p = 0.04), higher local tumor stage (≥T3) (p = 0.05), presence of visceral (p = 0.02) or cerebral metastases (p = 0.03) and increased mortality (p = 0.05). Further, patients with central PE showed an increased mortality compared to peripheral PE (p = 0.03), but no correlation was found between the localization of PE and the occurrence of clinical symptoms (p = 0.36). CONCLUSION: PE in patients with MM often occurs without clinical symptoms and is indicative for advanced disease and a poorer prognosis.

Comparison of CAIPIRINHA-accelerated 3D fat-saturated-SPACE MRI with 2D MRI sequences for the assessment of shoulder pathology.

OBJECTIVES: To compare the performance of 6-min MRI with a fat-saturated 3D-controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) Sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) TSE protocol with 10-min 2D TSE MRI protocol for assessment of abnormalities of the shoulder. METHODS: Forty-nine subjects underwent both 3D fat-saturated-CAIPIRINHA SPACE and 2D TSE sequences of the shoulder on a 3.0-T system. Following randomization and anonymization, two musculoskeletal radiologists evaluated the 2D and 3D images independently for image quality and diagnostic capability. Descriptive statistics, inter-observer, and inter-method concordance were investigated. p values < 0.05 were considered significant. RESULTS: For image quality assessment, 2D images were similar to 3D CAIPIRINHA SPACE images (p = 0.05). 3D had lower noise standard deviation (SD) and higher fluid CNR than 2D images (p = 0.00). For diagnostic capability assessment, using 2D TSE as a standard of reference, sensitivity, specificity, and accuracy of 3D SPACE were, respectively, 94.81%, 94.12%, and 94.39% for tendon abnormalities; 97.06%, 80.00%, and 91.84% for acromioclavicular joint abnormalities; 88.89%, 100.00%, and 93.89% for adjacent bone alterations; and 97.30%, 100%, and 97.96% for joint fluid/effusion assessment. The inter-method concordance was moderate to almost perfect. The inter-observer-concordance of the shoulder assessment was also moderate to almost perfect, with SSP lesions demonstrating the greatest concordance. CONCLUSIONS: The performance of 6-min 3D fat-saturated-CAIPIRINHA SPACE MRI for shoulder MRI is similar to that of 10-min 2D TSE MRI. 3D fat-saturated-CAIPIRINHA SPACE MRI can be utilized to reduce scan time without degradation in image quality. KEY POINTS: • CAIPIRINHA acceleration 3D fat-saturated-MRI of the shoulder is achievable in 6 min with high spatial resolution. • 3D fat-saturated CAIPIRINHA MRI is similar to 2D MRI in the shoulder assessment. • 3D CAIPIRINHA MRI images enable rapid diagnosis of shoulder abnormalities without image quality degradation.

Cross-reactivity among iodinated contrast agents: should we be concerned?

BACKGROUND: Although several papers deal with "cross-reactivity" in patients with iodinated contrast medium (ICM) hypersensitivity reactions (HSRs), there is no in-depth knowledge of this phenomenon. To define ICM-groups as potential reaction partners and to identify any potential clinical relevance in patients with ICM-HSRs. METHODS: The literature database PubMed was searched for eligible papers dealing with ICM-allergy and "cross-reactivity". The data presented by the papers was analyzed and individual patient data was extracted for re-evaluation based on a definition for both 'polyvalent reactivity' and 'cross-reactivity' as well as for chemical structure-dependent ICM-groups. RESULTS: Twenty-five original papers (with n=340 extracted patients) formed the study population. Incidences of polyvalent reactivity were non-significantly higher than incidences of cross-reactivity (both range from 0% to 100%). Crossover evaluation in reaction pairings (culprit ICM A with ICM B versus culprit ICM B with ICM A) showed concordance of only 30%. Data support rather non-cross-reactivity (individual reaction pattern) than cross-reactivity constellations. CONCLUSIONS: The obtained results favour an individual reaction pattern, rather than a reactivity driven by chemical structures and so-called cross-reactivity.

Utility of noncontrast MRI in the detection and risk grading of gastrointestinal stromal tumor: a comparison with contrast-enhanced CT.

BACKGROUND: Recently developed adjuvant therapies for gastrointestinal stromal tumor (GIST) have been shown to improve patient survival. Guidelines currently recommend contrast-enhanced computed tomography (CECT) for GIST detection and surveillance. Patients with moderate-to-high risk GISTs require more frequent surveillance due to a higher 5-year recurrence rate. Our study aimed to compare noncontrast magnetic resonance imaging (MRI) with CECT for GIST detection, and evaluate volumetric apparent diffusion coefficients (ADCs) for risk stratification of GIST. METHODS: We retrospectively enrolled 83 patients with histopathologically confirmed GISTs for lesion detection efficiency analysis between noncontrast MRI and matched CECT studies. A 5-point scale was used by two independent reviewers to determine if the lesion was present or absent. Another cohort, comprising 28 patients with pathologically confirmed primary GISTs, was further screened for risk stratification, with a comparison of volumetric ADC parameters between the pathologically very-low-to-low risk and moderate-to-high risk GIST patients. RESULTS: For identifying GISTs, the sensitivity and specificity of noncontrast MRI were 83.6% and 89.3% for reader 1 respectively, and 81.8% and 92.9% for reader 2 respectively; the sensitivity and specificity of CECT were 76.4% and 89.3% for reader 1 respectively, and 76.4 and 78.6% for reader 2 respectively. Tumor volumetric ADC histogram parameters, including ADCmax, ADCstdev, 90th and 95th percentiles, inhomogeneity, and entropy, were positively correlated with a higher risk grade of GIST (r=0.421-0.758). The receiver operator characteristic curve analysis showed ADCmax achieved the highest area under the curve value of 0.938 for discriminating very-low-to-low risk versus moderate-to-high risk GISTs. CONCLUSIONS: Noncontrast MRI was an efficient technique for identifying GIST patients. The combination of CECT and noncontrast MRI can improve the reliability of diagnosis. For patients with contraindications to CECT, noncontrast MRI may be a comparable alternative. Volumetric ADC histogram parameters may be useful in differentiating very-low-to-low risk from moderate-to-high risk primary GISTs.

CT facilitates improved diagnosis of adult intestinal malrotation: a 7-year retrospective study based on 332 cases.

OBJECTIVE: To classify adult intestinal malrotation by CT. METHODS: This retrospective study enrolled adults diagnosed with intestinal malrotation who underwent abdominal CT at our institution between June 1, 2013, and August 30, 2020. All patients' clinical information was recorded. Patients were divided into groups undergoing surgical and conservative management. The duodenum (nonrotation, partial rotation, and malrotation), jejunum, cecum, and the superior mesenteric artery/superior mesenteric vein relationship were reviewed on the CT images of each patient, and classification criteria developed based on the first three items. For each patient, each item was assessed separately by three radiologists. Consensus was required from at least two of them. RESULTS: A total of 332 eligible patients (218 men and 114 women; mean age 51.0 ± 15.3 years) were ultimately included and classified into ten types of malrotation. Duodenal partial rotation was present in most (73.2%, 243/332) with only 25% (83/332) demonstrating nonrotation. The jejunum was located in the right abdomen in 98.2% (326/332) of cases, and an ectopic cecum was found in only 12% (40/332, 29 cases with a left cecum, 7 pelvic, and 4 at midline). Asymptomatic patients comprised 56.6% (188/332) of cases, much higher than that in previous studies (17%, n = 82, p < .001), comprised mainly of patients with duodenal partial rotation (80.3%, 151/188). In 91 patients with detailed clinical data available (12 managed surgically and 79 conservatively), a significant difference in malrotation CT categorization was identified (p = .016). CONCLUSIONS: CT enables greater detection of asymptomatic intestinal malrotation, enabling classification into multiple potentially clinically relevant subtypes.

Differentiation of hepatocellular carcinoma from intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma in high-risk patients matched to MR field strength: diagnostic performance of LI-RADS version 2018.

PURPOSE: To eliminate the effects of field strength in determining the diagnostic performance of the LI-RADS version 2018 (LI-RADS v2018) in differentiating hepatocellular carcinoma (HCC) from non-HCC primary liver malignancy in high-risk patients. METHODS: Patients who were pathologically confirmed intrahepatic cholangiocarcinoma (iCCA) or combined hepatocellular-cholangiocarcinoma (cHCC-CCA) were retrospectively reviewed. Patients with HCC were matched to the iCCA or cHCC-CCA patients on age, tumor size, MR scanner, and number of tumors. Two readers independently evaluated the lesions according to LI-RADS v2018. Diagnostic performance of LI-RADS v2018 in differentiating HCC from non-HCC primary liver malignancy were analyzed. RESULTS: A total of 198 patients with 204 lesions (102 HCCs, 78 iCCAs, and 24 cHCC-CCAs) were enrolled. The sensitivity and specificity of LR-5 or LR-TIV (definitely due to HCC) in diagnosing HCC were 68.63% and 85.29%, respectively. LR-M or LR-TIV (may be due to non-HCC malignancy) had a sensitivity of 72.55% and a specificity of 86.27% in diagnosing non-HCC malignancy. The sensitivity of LR-M or LR-TIV (may be due to non-HCC malignancy) for iCCA and cHCC-CCA was 82.05% and 41.67%, respectively. Nearly half (11/24, 45.83%) of cHCC-CCAs were categorized as LR-5. Three tesla MR showed higher sensitivity than 1.5 T in diagnosing HCC (80.00% vs 57.69%, P = 0.015). CONCLUSION: When the effect of field strength was eliminated, LI-RADS v2018 demonstrated high specificity but suboptimal sensitivity in distinguishing HCC from non-HCC primary liver carcinomas. Most iCCAs were categorized as LR-M or LR-TIV (may be due to non-HCC malignancy). However, nearly half of cHCC-CCAs were assigned as LR-5.

The Diagnostic Value of MR IVIM and T2 Mapping in Differentiating Autoimmune Myositis From Muscular Dystrophy.

RATIONALE AND OBJECTIVES: To confirm the feasibility and compare the accuracy of magnetic resonance imaging intravoxel incoherent motion (IVIM) and T2 mapping models for the differentiation of autoimmune myositis from muscular dystrophy. MATERIALS AND METHODS: Fourty-two autoimmune myositis and 11 muscular dystrophy patients proven by diagnostic criteria were enrolled in the study. Conventional MR sequences, IVIM, and T2 mapping through the bilateral thighs were obtained as well as blood samples for all patients. IVIM and T2 mapping parameters as well as serum markers were compared between the autoimmune myositis and muscular dystrophy groups. Mann-Whitney U tests were performed for statistical analysis along with receiver operating characteristic curves. Spearman correlation coefficient models were constructed to analyze the correlation between IVIM and T2 mapping with serological parameters. RESULTS: The intramuscular apparent diffusion coefficient, tissue diffusivity (D), perfusion fraction (fp), and T2 relaxation time values were statistically significantly different between the autoimmune myositis and muscular dystrophy groups (p < 0.05). Pseudo diffusivity (Dp) values showed no statistical difference between the groups (p > 0.05). D parameter of IVIM sequences differentiated autoimmune and muscular dystrophy with a higher specificity of 75.60%. T2 values within the thighs were correlated with serum creatine kinase and lactate dehydrogenase levels (p < 0.05). CONCLUSION: Thigh muscle IVIM and T2 mapping parameters are useful in differentiating autoimmune myositis from muscular dystrophy, particularly the IVIM parameters.

Association Between MRI-Based Tibial Slope Measurements and Mucoid Degeneration of the Anterior Cruciate Ligament: A Propensity Score-Matched Case-Control Study.

BACKGROUND: The cause of mucoid degeneration (MD) of the anterior cruciate ligament (ACL), which is commonly observed on magnetic resonance imaging (MRI) of patients with knee pain, has yet to be elucidated. Despite the limited evidence on the relationship between ACL lesions (injury and MD) and tibial morphologic features (ie, posterior tibial slope), the potential association between the presence of ACL MD and medial and lateral tibial slope (MTS and LTS) has not been well-established. PURPOSE: To investigate whether MTS and LTS measurements are associated with the presence of ACL MD. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Consecutive knee MRI examinations of patients referred by an orthopaedic surgeon for potential internal joint derangements were identified within a 4-year period. The presence of ACL MD and the MTS/LTS values were assessed by independent expert observers in consensus in a blinded fashion. From 413 consecutive knee MRI scans, a sample of 80 knees, including 32 knees with ACL MD (cases) and 48 knees with normal ACL (controls), were selected using propensity score matching method for age, sex, body mass index, and presence of severe medial tibiofemoral compartment cartilage damage. The association between ACL MD and MTS/LTS was evaluated using conditional regression models. RESULTS: Knees with ACL MD had higher values of LTS (mean ± SD, 7.18° ± 3.58°) in comparison with control knees (5.32° ± 3.35°). Conditional regression analysis revealed a significant association between LTS measurements (not MTS) and ACL MD; every 1° increase in LTS was associated with a 17% (95% CI, 1%-35%) higher probability of having ACL MD. CONCLUSION: Excessive LTS was associated with the presence of ACL MD, independent of participants' age, sex, BMI, and cartilage damage severity.

Recognition of sacroiliac joint structural lesions: Comparison of volumetric interpolated breath-hold examination (VIBE) sequences with different slice thicknesses to T1-weighted turbo-echo.

PURPOSE: To compare volumetric interpolated breath-hold examination (VIBE) with different slice thicknesses to T1-weighted turbo-echo (T1 TSE) for identification of sacroiliac joint structural lesions in patients suspected of spondyloarthritis (SpA) using CT as the gold standard. METHODS: 192 sacroiliac joints (including VIBE with both 1.2 mm and 3 mm slice thickness, T1 TSE) from 96 patients suspected of SpA were included. Joint space changes and sclerosis were evaluated for each joint. Erosions were assessed both at the level of the individual sacral and iliac bones and at the level of the entire joint for calculation of sensitivity, specificity, and accuracy. MRI and CT correlation was performed and inter-reader reliability was determined. Fat infiltration on MRI was scored. RESULTS: VIBE with a 1.2 mm slice thickness was the most sensitive and accurate for erosion detection at the bone level followed by 3 mm thickness VIBE and then T1 TSE (p < 0.05). At the whole-joint level, only the 1.2 mm slice thickness VIBE was superior to T1 TSE in sensitivity and accuracy (p > 0.05). For joint space changes, both VIBE sequences were superior to T1 TSE in sensitivity and accuracy (p < 0.05) and had more consistency with CT. T1 TSE was slightly more sensitive for detection of sclerosis (p < 0.05). The MR sequences did not differ in detection of fat infiltration. CONCLUSION: A VIBE sequence with 1.2 mm slice thickness and less than one-minute acquisition time was superior to T1 TSE for detection of sacroiliac joint space changes and erosions in patients with suspected SpA, while the utility of the 3 mm slice thickness VIBE remains questionable.

Simultaneous Multislice Diffusion-Weighted Imaging of the Kidneys at 3 T.

PURPOSE: The aim of this study was to compare respiratory-triggered diffusion-weighted imaging with simultaneous-multislice acceleration (SMS-RT-DWI) to a standard free-breathing echoplanar DWI (s-DWI) for 3 T renal imaging with respect to image quality and artifacts. MATERIALS AND METHODS: A total of 40 patients who had undergone renal magnetic resonance imaging were included in this retrospective analysis of a prospectively planned cohort study. All examinations were performed on a 3 T whole-body magnetic resonance system. Both s-DWI and SMS-RT-DWI were obtained and images were independently reviewed by 2 radiologists on a 5-point Likert scale with respect to overall preference and image quality, renal edge and parenchymal sharpness, cortico-medullary differentiation, and sequence-related artifacts. Furthermore, discernibility of renal lesions was assessed. The signal-to-noise ratio (SNR) was measured from SNR maps. The derived mean apparent diffusion coefficients were also compared. Qualitative parameters were assessed with the Wilcoxon rank-sum test, and quantitative parameters, with the Student t test. RESULTS: Overall image quality, renal edge, and parenchymal sharpness of SMS-RT-DWI were rated as superior to s-DWI by the readers, with fewer sequence-related artifacts (P < 0.01 for all). Lesion discernibility was significantly improved for SMS-RT-DWI (P < 0.01). Both readers preferred SMS-RT-DWI to s-DWI in all cases (40/40). The acquisition time for SMS-RT-DWI was 30% shorter than for s-DWI. Mean SNR heterogeneity of SMS-RT-DWI at b = 800 s/mm was statistically significantly lower than s-DWI, whereas mean SNR was significantly higher for SMS-RT-DWI. Mean apparent diffusion coefficient values from both sequences were comparably homogeneous throughout the kidneys. CONCLUSION: Simultaneous multislice DWI of the kidney at 3 T with respiratory triggering yields substantially improved image quality and lesion discernibility compared with standard single-shot echoplanar DWI with a 30% reduction in scan acquisition time.

Histogram analysis with computed tomography angiography for discriminating soft tissue sarcoma from benign soft tissue tumor.

To investigate the feasibility of histogram analysis with computed tomography angiography (CTA) in distinguishing between soft tissue sarcomas and benign soft tissue tumors. Fourty nine patients (23 men, mean age = 44.3 years, age range = 25-64) with pathologically-confirmed soft tissue sarcoma (n = 24) or benign soft tissue tumors (n = 25) in the lower extremities undergoing CTA for tumor evaluation were retrospectively analyzed. Two radiologists separately performed histogram analyses of CT density with CTA images by drawing a region of interest (ROI). The 10th (P10), 25th (P25), 50th (P50), 75th (P75), 90th percentiles (P90), mean, and standard deviations (SD) of measured tumor density were obtained along with measurements of the absolute value of kurtosis (AVK), absolute value of skewness (AVS), and inhomogeneity for each tumor. Intra-class correlation coefficients (ICC) were calculated to determine inter- and intra-reader variability in parameter measurements. The Mann-Whitney U test was used to compare histogram parameters between soft tissue sarcomas and benign soft tissue tumors. Receiver operator characteristic (ROC) curves were constructed to evaluate the accuracy of tumor discrimination. ICC was greater than 0.7 for AVS, AVK, and inhomogeneity, and >0.9 for mean, SD, and all percentile measures. There was no significant difference in P10, P25, P50, P75, P90, mean, or SD between soft tissue sarcomas and benign tumors (P > .05). AVS, AVK, and inhomogeneity were significantly higher in soft tissue sarcomas (P < .05). Areas under the curve (AUC) were 0.81, 0.83, and 0.84 for AVS, AVK, and inhomogeneity respectively. AUC were below 0.6 for mean, SD, and all percentiles.Skewness, kurtosis, and inhomogeneity measurements derived from histogram analysis from CTA distinguish between soft tissue sarcomas and benign soft tissue tumors.

A Systematic Review of Technical Parameters for MR of the Small Bowel in non-IBD Conditions over the Last Ten Years.

Technical guidelines for magnetic resonance imaging (MRI) of the small bowel (SB) in the setting of inflammatory bowel diseases (IBDs) were detailed in a 2017 consensus issued by European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Pediatric Radiology (ESPR); however, MRI for non-IBD conditions was not addressed. Hence, we performed a systematic review collecting researches on SB MRI for non-IBDs. The literatures were then divided into morphologic group and functional group. Information about the MRI techniques, gastrointestinal preparation, and details of cine-MRI protocols was extracted. We found that a 1.5 T MRI system, prone positioning, and MR enterography were frequently utilized in clinical practice. Gadolinium contrast sequences were routinely implemented, while diffusion-weighted imaging (DWI) was much less performed. The gastrointestinal preparation varied throughout the studies. No uniform protocols for cine imaging could be established. SB MRI examinations for non-IBDs are far from standardized, especially for functional studies. Recommendations for standard parameters in cine-MRI sequences are difficult to make due to lack of evidentiary support. MRI investigations in non-IBD conditions are needed and the standardization of non-IBD imaging in clinical practice is required.

Quantitative diffusion-weighted magnetic resonance enterography in ileal Crohn's disease: A systematic analysis of intra and interobserver reproducibility.

BACKGROUND: Magnetic resonance enterography (MRE) is increasingly attractive as a noninvasive and radiation-free tool for assessing Crohn's disease (CD). Diffusion-weighted imaging (DWI) is recommended as an optional MRE sequence for CD by the European Society of Gastrointestinal and Abdominal Radiology, and has shown a superb potential as a quantitative modality for bowel inflammation evaluation. However, the measurement reproducibility of quantitative DWI analysis in MRE has not been ascertained so far. To facilitate the application of quantitative diffusion-weighted MRE in the clinical routine, systematic investigations of the intra and interobserver reproducibility of DWI quantitative parameters should be performed. AIM: To evaluate the intra and interobserver reproducibility of quantitative analysis for diffusion-weighted MRE (DW-MRE) in ileal CD. METHODS: Forty-four subjects (21 with CD and 23 control subjects) who underwent ileocolonoscopy and DW-MRE (b = 800 s/mm2) within one week were included. Two radiologists independently measured apparent diffusion coefficients (ADC) of the terminal ileum and signal intensity ratio (SR) of the terminal ileum to ipsilateral psoas muscle on DWI images (b = 800 s/mm2). Between- and within-reader agreements were assessed using intraclass correlation coefficients (ICC), coefficients of variation (CoV), and 95% limits of agreement of Bland-Altman plots (BA-LA LoA). Diagnostic performances of ADC and SR for identifying inflamed terminal ileum from the normal were evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: There were no significant differences in ADC or SR values between the two sessions or between the two radiologists either in the CD or control group (paired t-test, P > 0.05). The intra and interobserver reproducibility of ADC (ICC: 0.952-0.984; CoV: 3.73-6.28%; BA-LA LoA: ±11.27% to ±15.88%) and SR (ICC: 0.969-0.989; CoV: 3.51%-4.64%; BA-LA LoA: ±10.62% to ±15.45%) was excellent for CD. Agreement of ADC measurements was slightly less in control subjects (ICC: 0.641-0.736; CoV: 10.47%-11.43%; BA-LA LoA: ± 26.59% to ± 30.83%). SR of normal terminal ileum demonstrated high intra and interobserver reproducibility (ICC: 0.944-0.974; CoV: 3.73%-6.28%; BA-LA LoA: ± 18.58% to ± 24.43%). ADC and SR of two readers had outstanding diagnostic efficiencies (area under the ROC curve: 0.923-0.988). CONCLUSION: Quantitative parameters derived from DW-MRE have good to excellent intra and interobserver agreements with high diagnostic accuracy, and can serve as robust and efficient quantitative biomarkers for CD evaluation.