Magnetic Resonance Imaging Correlation Research Articles

Case Series: Multiple Soft Tissue Lesions Demonstrated by Sonography and MRI Correlation

Varied diagnostic imaging techniques may often be used in tandem, to enhance and complement each other, when an initial imaging diagnosis appears equivocal. Diagnostic medical sonography and magnetic resonance imaging (MRI) are imaging techniques that often complement each another. Sonography is an excellent diagnostic technique to determine the consistency of a soft tissue mass (e.g., solid vs cystic), and its relationship to adjacent structures, size, and shape. Sonography is especially useful for evaluating palpable lumps and allows sonographers to perform targeted examinations around the area of interest. In addition, color and pulsed-wave Doppler enable further characterization of a lesion’s presence or lack of vascularity. Sonography can also guide core-needle biopsy of superficial lesions. However, sonography is less reliable for deep masses in large anatomical regions. The American College of Radiology recommends MRI for deeper lesions of this type. Magnetic resonance imaging is also recommended for soft tissue masses suspected to be localized to the peripheral nervous system.

Comparison of ultrasonic shear wave elastography, AngioPLUS planewave ultrasensitive imaging, and optimized high-resolution magnetic resonance imaging in evaluating carotid plaque stability.

This study aimed to compare the efficiency of evaluating carotid plaque stability using ultrasonic shear wave elastography (SWE), AngioPLUS planewave ultrasensitive imaging (AP), and optimized high-resolution magnetic resonance imaging (MRI). A total of 100 patients who underwent carotid endarterectomy at our hospital from October 2019 to August 2022 were enrolled. Based on the final clinical diagnosis, these patients were divided into vulnerable (n=62) and stable (n=38) plaque groups. All patients were examined using ultrasound SWE, AP, and optimized high-resolution MRI before surgery. The clinical data and ultrasound characteristics of patients of the two groups were compared. Considering the final clinical diagnosis as the gold standard, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SWE, AP, high-resolution MRI, and the final clinical diagnosis of vulnerable plaque were calculated. Pearson's correlation test was used to analyze the correlations of AP, SWE, and MRI results with the grading results of carotid artery stenosis. Statistically significant differences were noticed in terms of the history of smoking and coronary heart disease, plaque thickness, surface rules, calcified nodules, low echo area, and the degree of carotid artery stenosis between the two groups (P<0.05). Considering the final clinical diagnosis as the gold standard, the sensitivity, specificity, PPV, and NPV of SWE-based detection of carotid artery vulnerability were 87.10% (54/62), 76.32% (29/38), 85.71% (54/63) and 78.38% (29/37), respectively, showing a general consistency with the final clinical results (Kappa = 0.637, P<0.05). Considering the final clinical diagnosis as the gold standard, the sensitivity, specificity, PPV and NPV of AP-based detection of carotid artery vulnerability were 93.55% (58/62), 84.21% (32/38), 90.63% (58/64), and 88.89% (32/36), respectively, which agreed with the final clinical detection results (Kappa = 0.786, P<0.05). Considering the final clinical diagnosis as the gold standard, the sensitivity, specificity, PPV and NPV of high-resolution MRI-based detection of carotid artery vulnerability were 88.71% (55/62), 78.95% (30/38), 87.30% (55/63), and 81.08% (30/37), respectively, showing consistency with the final clinical results (Kappa = 0.680, P<0.05). AP, SWE, and MRI results were positively correlated with the results of carotid artery stenosis grading (P<0.05). AP technology is a non-invasive, inexpensive, and highly sensitive method to evaluate the stability of carotid artery plaques. This method can dynamically display the flow of blood in new vessels of plaque in real time and provide a reference for clinical diagnosis and treatment.

A Cellular Ground Truth to Develop MRI Signatures in Glioma Models by Correlative Light Sheet Microscopy and Atlas-Based Coregistration.

Glioblastoma is the most common malignant primary brain tumor with poor overall survival. Magnetic resonance imaging (MRI) is the main imaging modality for glioblastoma but has inherent shortcomings. The molecular and cellular basis of MR signals is incompletely understood. We established a ground truth-based image analysis platform to coregister MRI and light sheet microscopy (LSM) data to each other and to an anatomic reference atlas for quantification of 20 predefined anatomic subregions. Our pipeline also includes a segmentation and quantification approach for single myeloid cells in entire LSM datasets. This method was applied to three preclinical glioma models in male and female mice (GL261, U87MG, and S24), which exhibit different key features of the human glioma. Multiparametric MR data including T2-weighted sequences, diffusion tensor imaging, T2 and T2* relaxometry were acquired. Following tissue clearing, LSM focused on the analysis of tumor cell density, microvasculature, and innate immune cell infiltration. Correlated analysis revealed differences in quantitative MRI metrics between the tumor-bearing and the contralateral hemisphere. LSM identified tumor subregions that differed in their MRI characteristics, indicating tumor heterogeneity. Interestingly, MRI signatures, defined as unique combinations of different MRI parameters, differed greatly between the models. The direct correlation of MRI and LSM allows an in-depth characterization of preclinical glioma and can be used to decipher the structural, cellular, and, likely, molecular basis of tumoral MRI biomarkers. Our approach may be applied in other preclinical brain tumor or neurologic disease models, and the derived MRI signatures could ultimately inform image interpretation in a clinical setting.SIGNIFICANCE STATEMENT We established a histologic ground truth-based approach for MR image analyses and tested this method in three preclinical glioma models exhibiting different features of glioblastoma. Coregistration of light sheet microscopy to MRI allowed for an evaluation of quantitative MRI data in histologically distinct tumor subregions. Coregistration to a mouse brain atlas enabled a regional comparison of MRI parameters with a histologically informed interpretation of the results. Our approach is transferable to other preclinical models of brain tumors and further neurologic disorders. The method can be used to decipher the structural, cellular, and molecular basis of MRI signal characteristics. Ultimately, information derived from such analyses could strengthen the neuroradiological evaluation of glioblastoma as they enhance the interpretation of MRI data.

Brain MRI correlations with disease burden and biomarkers in Fabry disease

ObjectiveTo quantitatively evaluate cerebral small vessel disease (CSVD) in brain magnetic resonance imaging (MRI) and its correlation with disease burden and markers in Fabry disease, a rare X-linked lysosomal storage disease.MethodsWe collected brain MRI data from seventy-one Chinese patients with Fabry disease. CSVD was evaluated using an age-related white matter change rating scale, Fazekas scale, enlarged perivascular spaces grading scale, lacunar infarction scale, Microbleed Anatomical Rating Scale, global cortical atrophy scale, and small-vessel disease score. Factors associated with MRI lesions, including sex, clinical subtype, disease severity, disease burden, genotype, and biomarkers, were also analyzed.ResultsOf 71 patients, 16 (22.5%) experienced ischemic stroke. The incidences of lacunar infarctions, white matter hyperintensities, and cerebral microbleeds were 55%, 62%, and 33%, respectively. The abnormal MRI group had later disease onset, longer disease duration, and a higher Mainz Severity Score Index (p < 0.05) than the normal MRI group. Patients with more severe clinical phenotypes also had higher CVSD-related scores. Sex and GLA mutational type were not closely associated with brain MRI lesions. Of the disease markers, the Mainz Severity Score Index and plasma globotriaosylsphingosine (Lyso-Gb3) were closely correlated with the majority of the MRI scores, whereas α-galactosidase A activity was not.ConclusionBrain MRI revealed progressive lacunar infarctions, white matter hyperintensities, and decreased brain volume in patients with Fabry disease. Brain MRI lesions were closely related to onset-age; disease duration, severity, burden; and plasma Lyso-Gb3. However, they were not associated with sex, α-galactosidase A activity, or GLA mutation type.

Region-focused multi-view transformer-based generative adversarial network for cardiac cine MRI reconstruction.

Cardiac cine magnetic resonance imaging (MRI) reconstruction is challenging due to spatial and temporal resolution trade-offs. Temporal correlation in cardiac cine MRI is informative and vital for understanding cardiac dynamic motion. Exploiting the temporal correlations in cine reconstruction is crucial to resolve aliasing artifacts and maintaining the cardiac motion patterns. However, existing methods have the following shortcomings: (1) they simultaneously compute pairwise correlations along spatial and temporal dimensions to establish dependencies, ignoring that learning spatial contextual information first will benefit the temporal modeling. (2) most studies neglect to focus on reconstructing the local cardiac regions, resulting in insufficient reconstruction accuracy due to a relatively large field of view. To address these problems, we propose a region-focused multi-view transformer-based generative adversarial network for cardiac cine MRI reconstruction. The proposed transformer divides consecutive cardiac frames into multiple views for cross-view feature extraction, establishing long-distance dependencies among features and effectively learning the spatio-temporal information. We further design a cross-view attention for spatio-temporal information fusion, ensuring the interaction of different spatio-temporal information in each view and capturing more temporal correlations of the cardiac motion. In addition, we introduce a cardiac region detection loss for improving the reconstruction quality of the cardiac region. Experimental results demonstrated that our method outperforms state-of-the-art methods. Especially with an acceleration factor as high as 10×, our method can reconstruct images with better accuracy and perceptual quality.

Correlation of Ultrasonography and MRI with Electrodiagnostic Studies in Carpal Tunnel Syndrome.

Background: One controversial question in Carpal Tunnel Syndrome (CTS) diagnosis is whether magnetic resonance imaging (MRI) and Ultrasound (US) imaging tools have any relationship with electrodiagnostic (EDX) study. The objective of this study is to determine the possible correlation between MRI and US measurements with EDX parameters. Methods: Both US and MRI of the median nerve were simultaneously performed in 12 confirmed CTS wrists, at two levels of forearm distal fold (proximal) and the hook of the hamate (distal), to measure various anatomic parameters of the nerve. EDX parameters of median motor distal latency (DL) and median sensory proximal latency (PL) were evaluated in milliseconds. Results: Nerve cross-sectional area (CSA), measured by MRI, correlated with sensory PL at distal level (p = 0.015). At proximal level MRI, nerve width and width to height ratio also correlated with motor DL (p = 0.033 and 0.021, respectively). Median nerve CSA proximal to distal ratio correlated with sensory PL (p = 0.028) at MRI. No correlation was found between US and EDX measurements. Conclusions: Median nerve MRI measurement of nerve CSA at hook of the hamate (distal) level or CSA proximal to distal ratio correlated with EDX parameter of sensory PL. On the other hand, nerve MRI width and width to height ratio at distal level correlated with motor DL in EDX. Level of Evidence: Level III (Diagnostic).

Segmented solenoid RF coils for MRI of ex vivo brain samples at ultra-high field preclinical and clinical scanners

Magnetic resonance imaging (MRI) is a well-known and widespread imaging modality for neuroscience studies and the clinical diagnoses of neurological disorders, mainly due to its capability to visualize brain microstructures and quantify various metabolites. Additionally, its noninvasive nature makes possible the correlation of high-resolution MRI from ex vivo brain samples with histology, supporting the study of neurodegenerative disorders such as Alzheimer's or Parkinson's disease. However, the quality and resolution of ex vivo MRI highly depend on the availability of specialized radiofrequency coils with maximized filling factors for the different sizes and shapes of the samples to be studied. For instance, small, dedicated radiofrequency (RF) coils are not always commercially available in ultrahigh field whole-body MRI scanners. Even for ultrahigh field preclinical scanners, specific RF coils for ex vivo MRI are expensive and not always available. Here, we describe the design and construction of two RF coils based on the solenoid geometry for ex vivo MRI of human brain tissues in a 7T whole-body scanner and for ex vivo MRI of marmoset brain samples in a 9.4T preclinical scanner. We designed the 7T solenoid RF coil to maximize the filling factor of human brain samples conditioned on cassettes for histology, while the 9.4T solenoid was constructed to accommodate marmoset brain samples conditioned in 50 ml centrifuge tubes. Both solenoid designs operate in transceiver mode. The measured B1+ maps show a high level of homogeneity in the imaging volume of interest, with a high signal-to-noise ratio over the imaging volume. High-resolution (80 µm in plane, 500 µm slice thickness) images of human brain samples were acquired with the 7T solenoid, while marmoset brain samples were acquired with an isotropic resolution of 60 µm using the 9.4T solenoid coil.

Role of magnetic resonance imaging and 18-fluorodeoxyglucose positron emission tomography-computed tomography in identifying pain generators in patients with chronic low back pain.

Low back pain (LBP) is a major cause of pain and disability. Identification of the pathology accurately or the pain generators is sometimes difficult with the conventional modalities such as magnetic resonance imaging (MRI), computed tomography (CT), or X-ray. Nuclear medicine investigations such as single-photon emission CT (SPECT/CT) or 18-fluorodeoxyglucose positron emission tomography-CT (18-FDG PET-CT) have emerged as an adjuvant tool in these cases. In this study, we evaluated and analyzed the role of 18-FDG PET-CT in identifying active pain generators and the outcomes of interventions based on that compared to MRI. This study included all patients who fell under inclusion criteria presented with chronic LBP with or without radiculopathy. History and clinical examination were done as well as Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores were calculated. All the patients underwent MRI lumbosacral spine with sacroiliac (SI) joint and 18-FDG PET-CT whole spine. Patients in whom PET-CT was positive and active pain generator was identified were managed for the specific level or pain generator responsible by appropriate modalities, i.e. surgery, interfacetal injections, transforaminal epidural injections, and SI joint injections. Patients in whom PET-CT was negative were managed according to the pain generator identified on the basis of MRI and clinical correlation. Patients were told to follow-up after 1 week and 1 month, and subsequent improvement was evaluated on the basis of VAS after 1 week and 1 month and ODI score after 1 month. A total of 20 patients were included in the study, with a mean age of 41.9 ± 13.53 years. Twelve patients had multiple level pathology without the indication of significant pain generator and eight patients' symptoms did not correlate with the MRI findings. 18-FDG PET-CT was done in all patients. 10% (2/20) patients were identified with active pain generators on PET-CT which were not identified on MRI. Eleven out of twenty patients underwent intervention in the form of surgery or pain injections. The mean VAS and ODI score in the patients intervened on the basis of 18-FDG PET-CT improved by 70.59% and 50%, respectively, whereas in patients who underwent intervention on the basis of MRI had improvement in mean VAS and ODI score by 58.57% and 30.81%, respectively after 1 month. Inflammation and associated degenerative process in the spine is a continuous process and affects multiple levels and might not be easily picked up on MRI or other conventional modalities. Thus, 18-FDG PET-CT is useful in identifying these active inflammatory processes and thereby helping in the localization of active pain generators. Treating these active pain generators has a better outcome in patients after intervention in terms of better pain relief and quality of life and also reduces the levels being treated.

Agreement between intraoperative and magnetic resonance imaging assessments of rotator cuff pathology and 2 magnetic resonance imaging-based assessments of supraspinatus muscle atrophy.

Magnetic resonance imaging (MRI)-based rotator cuff assessment is often qualitative and subjective; few studies have tried to validate such preoperative assessments. This study investigates relationships of preoperative MRI assessments made by conventional approaches to intraoperative findings of tear type, location, and size or MRI-assessed muscle occupation ratio. Intraoperatively, surgeons assessed tear type, location, anterior-posterior (AP) width, and medial-lateral length in 102 rotator cuff repair patients. Two musculoskeletal radiologists independently assessed the preoperative MRI scans for these same parameters and supraspinatus muscle atrophy by both Warner classification and quantitative occupation ratio. Exact agreement proportions, kappa statistics, and correlation coefficients were used to quantify agreement relationships. Agreement between MRI readers' and surgeons' observations of tear status averaged 93% with κ=0.38, and that of tear location averaged 77% with κ=0.50. Concordance correlations of MRI and intraoperative measures of anterior-posterior and medial-lateral tear length averaged 0.59 and 0.56 across readers, respectively. Despite excellent interrater agreement on Warner classification (exact agreement proportion 0.91) and occupation ratio (concordance correlation 0.93) separately, correlations between these 2 measures were-0.54 and-0.64 for the 2 readers, respectively. Patients with Warner grade 0 had occupation ratios ranging from 0.5 to 1.5. Correlations of preoperative MRI tear dimensions and muscle atrophy assessed by conventional approaches with intraoperatively measured tear dimensions and quantitative occupation ratio, respectively, were only fair. Since tear size and muscle atrophy are known strong predictors of outcomes following rotator cuff repair that may influence treatment decisions, surgeons need to be aware of the limitations of MRI methods. Continued development and validation of quantitative preoperative imaging methods to accurately assess these parameters are needed to improve surgical planning and prognosis.

CME Rheumatology 26: Bone Marrow Edema of the Sacro-Iliac Joint = Spondyloarthritis? What the General Practicioner Should Know

CME Rheumatology 26: Bone Marrow Edema of the Sacro-Iliac Joint = Spondyloarthritis? What the General Practicioner Should Know Abstract. Axial spondyloarthritis is a chronic inflammatory joint disease mainly involving the sacroiliac joints (ISG) and the spine. The diagnosis can be made early due to acute inflammatory changes in the ISG on magnetic resonance imaging (MRI). Radiographs of the ISG do not help in early diagnosis because structural damage is not apparent on radiographs until an advanced stage. In recent years, however, several studies have shown that bone marrow edema - hyperintense signals (= bright spots) as a possible MRI correlate for inflammation - does not specifically occur in axial spondyloarthritis, but can also be seen in healthy people, athletes, people with high mechanical stress (e.g. military recruits) and postpartum women. The diagnosis of axial spondyloarthritis should therefore never be based solely on an MRI finding, but must always include the overall clinical context.

Direct correlation of MRI with histopathology in pediatric renal tumors through the use of a patient-specific 3-D-printed cutting guide: a feasibility study

BackgroundPediatric renal tumors are often heterogeneous lesions with variable regions of distinct histopathology. Direct comparison between in vivo imaging and ex vivo histopathology might be useful for identification of discriminating imaging features.ObjectiveThis feasibility study explored the use of a patient-specific three-dimensional (3D)-printed cutting guide to ensure correct alignment (orientation and slice thickness) between magnetic resonance imaging (MRI) and histopathology.Materials and methodsBefore total nephrectomy, a patient-specific cutting guide based on each patient’s preoperative renal MRI was generated and 3-D printed, to enable consistent transverse orientation of the histological specimen slices with MRI slices. This was expected to result in macroscopic slices of 5 mm each. The feasibility of the technique was determined qualitatively, through questionnaires administered to involved experts, and quantitatively, based on structured measurements including overlap calculation using the dice similarity coefficient.ResultsThe cutting guide was used in eight Wilms tumor patients receiving a total nephrectomy, after preoperative chemotherapy. The median age at diagnosis was 50 months (range: 4–100 months). The positioning and slicing of the specimens were rated overall as easy and the median macroscopic slice thickness of each specimen ranged from 5 to 6 mm. Tumor consistency strongly influenced the practical application of the cutting guide. Digital correlation of a total of 32 slices resulted in a median dice similarity coefficient of 0.912 (range: 0.530–0.960).ConclusionWe report the feasibility of a patient-specific 3-D-printed MRI-based cutting guide for pediatric renal tumors, allowing improvement of the correlation of MRI and histopathology in future studies.

Correlation of dynamic contrast-enhanced MRI and diffusion-weighted MR imaging with prognostic factors and subtypes of breast cancers.

ObjectiveTo determine the preoperative magnetic resonance imaging (MRI) findings of breast cancer on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted magnetic resonance imaging (DWI) in different molecular subtypes.Materials and methodsA retrospective study was conducted on 116 breast cancer subjects who underwent preoperative MRI and surgery or biopsy. Three radiologists retrospectively assessed the morphological and kinetic characteristics on DCE-MRI and tumor detectability on DWI, by using apparent diffusion coefficient (ADC) values of lesions. The clinicopathologic and MRI features of four subtypes were compared. The correlation between clinical and MRI findings with molecular subtypes was evaluated using the chi-square and ANOVA tests, while the Mann–Whitney test was used to analyze the relationship between ADC and prognostic factors.ResultsOne hundred and sixteen women diagnosed with breast cancer confirmed by surgery or biopsy had the following subtypes of breast cancer: luminal A (27, 23.3%), luminal B (56, 48.2%), HER2 positive (14, 12.1%), and triple-negative breast cancer (TNBC) (19, 16.4%), respectively. Among the subtypes, significant differences were found in axillary node metastasis, histological grade, tumor shape, rim enhancement, margin, lesion type, intratumoral T2 signal intensity, Ki-67 index, and paratumoral enhancement (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p = 0.02, respectively). On DWI, the mean ADC value of TNBC (0.910 × 10−3 mm2/s) was the lowest compared to luminal A (1.477×10−3 mm2/s), luminal B (0.955 × 10−3 mm2/s), and HER2 positive (0.996 × 10−3 mm2/s) (p < 0.001). Analysis of the correlation between different prognostic factors and ADC value showed that only axillary lymph node status and ADC value had a statistically significant difference (p = 0.009).ConclusionThe morphologic features of MRI can be used as imaging biomarkers to identify the molecular subtypes of breast cancer. In addition, quantitative assessments of ADC values on DWI may also provide biological clues about molecular subtypes.

Correlation of Postoperative Imaging With MRI and Clinical Outcome After Cartilage Repair of the Ankle: A Systematic Review and Meta-analysis.

Background:Magnetic resonance imaging (MRI) is commonly used for evaluation of ankle cartilage repair, yet its association with clinical outcome is controversial. This study analyzes the correlation between MRI and clinical outcome after cartilage repair of the talus including bone marrow stimulation, cell-based techniques, as well as restoration with allo- or autografting.Methods:A systematic search was performed in MEDLINE, Embase, and Cochrane Collaboration. Articles were screened for correlation of MRI and clinical outcome. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) were used. Chi-square test and regression analysis were performed to identify variables that determine correlation between clinical and radiologic outcome.Results:Of 2687 articles, a total of 43 studies (total 1212 cases) were included with a mean Coleman score of 57 (range, 33-70). Overall, 93% were case series, and 5% were retrospective and 2% prospective cohort studies. Associations between clinical outcome and ≥1 imaging variable were found in 21 studies (49%). Of 24 studies (56%) using the composite magnetic resonance observation of cartilage repair tissue (MOCART) score, 7 (29%) reported a correlation of the composite score with clinical outcome. Defect fill was associated with clinical outcome in 5 studies (12%), and 5 studies (50%) reported a correlation of T2 mapping and clinical outcome. Advanced age, shorter follow-up, and larger study size were associated with established correlation between clinical and radiographic outcome (P = .021, P = .028, and P = .033).Conclusion:Interpreting MRI in prediction of clinical outcome in ankle cartilage repair remains challenging; however, it seems to hold some value in reflecting clinical outcome in patients with advanced age and/or at a shorter follow-up. Yet, further research is warranted to optimize postoperative MRI protocols and assessments allowing for a more comprehensive repair tissue evaluation, which eventually reflect clinical outcome in patients after cartilage repair of the ankle.Level of Evidence: Level III, systematic review and meta-analysis.

Role of Transcutaneous Perianal Ultrasonography in Evaluation of Perianal Fistulae with MRI Correlation.

Purpose: The aim of this study was to evaluate the role of transcutaneous perianal ultrasonography (TPUS) in patients with perianal fistula and to correlate the findings with magnetic resonance imaging (MRI) as gold standard. Materials and Methods: This prospective study included patients who presented with suspicion of perianal fistula. After clinical examination, TPUS and MRI of perianal region were performed on each of them. Clockwise position of internal opening of the fistula was described. The entire length of the tract was evaluated up to the external opening. Also, any ramifications along the primary tract were described. Parks et al and St James's University Hospital MR Imaging Classification of Perianal Fistulas were used for classifying the fistulas. Results: Out of total 37 patients, the most common age group of presenting individuals was 45 to 60 years with male to female ratio of 6.4:1. There was excellent agreement between TPUS and MRI for detecting primary fistulous tract with kappa correlation coefficient of 1. The kappa correlation coefficient for detecting secondary fistulous tracts and abscess on TPUS and MRI was 0.839 and 0.937 showing excellent agreement. Moderate agreement was seen with kappa correlation coefficient of 0.839 in the detection of internal opening on TPUS and MRI. Conclusion: TPUS showed promising results in diagnosis and classification of perianal fistulae with MRI as gold standard. A wide availability, cost-effectiveness, and better tolerability of TPUS can make it an imaging modality of first choice for evaluating perianal fistulae.

Population-based cohort imaging: skeletal muscle mass by magnetic resonance imaging in correlation to bioelectrical-impedance analysis.

BackgroundSkeletal muscle mass is subjected to constant changes and is considered a good predictor for outcome in various diseases. Bioelectrical‐impedance analysis (BIA) and magnetic resonance imaging (MRI) are approved methodologies for its assessment. However, muscle mass estimations by BIA may be influenced by excess intramuscular lipids and adipose tissue in obesity. The objective of this study was to evaluate the feasibility of quantitative assessment of skeletal muscle mass by MRI as compared with BIA.MethodsSubjects from a population‐based cohort underwent BIA (50 kHz, 0.8 mA) and whole‐body MRI including chemical‐shift encoded MRI (six echo times). Abdominal muscle mass by MRI was quantified as total and fat‐free cross‐sectional area by a standardized manual segmentation‐algorithm and normalized to subjects' body height2 (abdominal muscle mass indices: AMMIMRI).ResultsAmong 335 included subjects (56.3 ± 9.1 years, 56.1% male), 95 (28.4%) were obese (BMI ≥ 30 kg/m2). MRI‐based and BIA‐based measures of muscle mass were strongly correlated, particularly in non‐obese subjects [r < 0.74 in non‐obese (P < 0.001) vs. r < 0.56 in obese (P < 0.001)]. Median AMMITotal(MRI) was significantly higher in obese as compared with non‐obese subjects (3246.7 ± 606.1 mm2/m2 vs. 2839.0 ± 535.8 mm2/m2, P < 0.001, respectively), whereas the ratio AMMIFat‐free/AMMITotal (by MRI) was significantly higher in non‐obese individuals (59.3 ± 10.1% vs. 53.5 ± 10.6%, P < 0.001, respectively). No significant difference was found regarding AMMIFat‐free(MRI) (P = 0.424). In analyses adjusted for age and sex, impaired glucose tolerance and measures of obesity were significantly and positively associated with AMMITotal(MRI) and significantly and inversely with the ratio AMMIFat‐free(MRI)/AMMITotal(MRI) (P < 0.001).ConclusionsMRI‐based assessment of muscle mass is feasible in population‐based imaging and strongly correlated with BIA. However, the observed weaker correlation in obese subjects may explain the known limitation of BIA in obesity and promote MRI‐based assessments. Thus, skeletal muscle mass parameters by MRI may serve as practical imaging biomarkers independent of subjects' body weight.

Correlation of the Histological ICRS II Score and the 3D MOCART Score for the Analysis of Aged Osteochondral Regenerates in a Large Animal Model.

ObjectiveReliable outcome measures are essential to predict the success of cartilage repair techniques. Histology is probably the gold standard, but magnetic resonance imaging (MRI) has the potential to decrease the need for invasive histological biopsies. The 3D magnetic resonance observation of cartilage repair tissue (MOCART) score is a reliable yet elaborate tool. Moreover, literature is controversial concerning the correlation of histology and MRI.DesignTo test the applicability of the International Cartilage Regeneration and Joint Preservation Society (ICRS) II and MOCART 3D score for the evaluation of aged osteochondral regenerates in a large animal model, and to identify correlating histological and MRI parameters. Osteochondral defects in medial femoral condyles of n = 12 adult sheep were reconstructed with biodegradable bilayer implants. About 19.5 months postoperation, n = 10 joints were analyzed with MRI (3D MOCART score). Histological samples were analyzed using the ICRS II score; both pre- and post-training. The intraclass correlation coefficient, the inter-rater reliability, and the 95% confidence interval were calculated. Matching histological and MRI parameters were tested for correlation.ResultsWe found a statistically significant correlation of all histological parameters. MRI parameters reflecting “overall” assessments had very strong inter-rater correlations. Statistically significant strong correlations were found for the MRI parameters defect filling, cartilage interface, bone interface, and surface. For defect overall (MRI) and overall assessment (ICRS II), we found a significant yet mild correlation.ConclusionsThe ICRS II and the 3D MOCART score are applicable to aged osteochondral regenerates. Prior training on the scoring systems is essential. Select MRI and histological parameters correlate; however, the only statistically significant correlation was found for overall assessment.

Magnetic resonance imaging vs. computed tomography image concordance for linear measurements and the quantification of abdominal skeletal muscle

AbstractBackgroundLinear measurement analysis using computed tomography (CT) scans to quantify abdominal muscle mass has been validated as a clinically practical approach for screening individuals with low muscle mass. However, there is still a need to validate such analysis using magnetic resonance imaging (MRI) imaging. The aim of this study is to assess the reproducibility and concordance of CT and MRI imaging for linear measurement analyses of skeletal muscle at mid‐L3.MethodsWe retrospectively analysed 66 patients with available CT and MRI images within 30 days of one other to evaluate linear measurement CT and MRI concordance. Linear measurement analysis for abdominal/pelvic CT and MRI scans for eight patients was conducted independently three times by the same person separated by at least 1 week to assess intra‐rater variability. The intra‐observer variability for both CT and MRI was assessed using the intraclass correlation coefficient (ICC). The concordance and correlation of CT and MRI mid‐L3 for linear measurements were assessed using Pearson correlation coefficients and Bland–Altman plots.ResultsThe intra‐rater reliability of linear measurements for both CT and MRI was high, as measured by the ICC (CT range: 0.788–0.992; MRI range: 0.766–0.984). CT and MRI linear measurements were found to be significantly positively correlated for all psoas (total psoas r = 0.98; P &lt; 0.0001) and paraspinal muscle measurements (total paraspinal r = 0.99; P &lt; 0.0001). Bland–Altman analysis revealed a mean bias of 0.83 (range: 0.03–5.56) for MRI over CT linear measurements.ConclusionsCT and MRI images were shown to be concordant for linear measurement analysis of abdominal muscle mass. T2‐weighted MRI sequences can be used interchangeably with CT in the assessment of sarcopenia using linear measurement analysis.

Imaging of the medial collateral ligament of the knee: a systematic review

IntroductionThe primary aim of this investigation was to systematically review relevant literature of various imaging modalities (magnetic resonance imaging (MRI), stress radiography and ultrasonography) in the assessment of patients with a medial collateral ligament (MCL) injury.Materials and methodsA systematic literature review of articles indexed in PubMed and Cochrane library was performed. Original research reporting data associated with medial gapping, surgical, and clinical findings associated with MCL injuries were considered for inclusion. The methodological quality of each inclusion was also assessed using a verified tool.ResultsTwenty-three imaging studies (magnetic resonance imaging (MRI) n = 14; ultrasonography n = 6; radiography n = 3) were ultimately included into the review. A total of 808 injured, and 294 control, knees were assessed. Interobserver reliabilities were reported in radiographic and ultrasonographic investigations with almost perfect agreement. MRI studies demonstrated agreement ranging between substantial to almost perfect. Intraobserver reliability was only reported in radiographic studies pertinent to medial gapping and was found to be almost perfect. Correlation of MRI with clinical findings was moderate to strong (65–92%). Additionally, MRI imaging was more sensitive in the detection of MCL lesions when compared to clinical examination. However, when compared to surgical findings, MRI underestimated the grade of instability in up to 21% of cases. Furthermore, MRI showed relatively inferior performance in the identification of the exact MCL-lesion location when compared to surgical findings. Interestingly, preoperative clinical examination was slightly inferior to stress radiography in the detection of MCL lesions. However, clinical testing under general anaesthesia performed similar to stress radiography. The methodological quality analysis showed a low risk of bias regarding patient selection and index testing in each imaging modality.ConclusionMRI can reliably diagnose an MCL lesion but demonstrates limitations in its ability to predict the specific lesion location or grade of MCL instability. Ultrasonography is a widely available, radiation free modality, but is rarely used in clinical practice for detecting MCL lesions and clinical or surgical correlates are scarce. Stress radiography findings correlate with surgical findings but clinical correlations are missing in the literature.Level of evidenceIV.

Knee pain: Ultrasound and MRI correlation

Abstract Background Knee pain incidence is increasing among the community which has different multiple pathologies. Magnetic Resonance Imaging (MRI) is considered the gold standard imaging modality in diagnosing knee soft tissue injury. Ultrasound (US) is another modality which can be used in diagnosing soft tissue injury. Aim of the Work is to detect the reliability of US in diagnosing cases with knee pain as compared to MRI. Patients and Methods A prospective study was conducted on 20 patients with knee pain. They were referred from the Orthopedic and/or Rheumatology Department to Radiology department at Ain Shams University hospitals for MRI and US examination of the knee.The age group were from 19 to 59 years. Results In this study, 20 patients were examined with majority being males (75%). US was tested against MRI for different soft tissue pathologies.including knee effusion, meniscal pathology (tear, degeneration and extrusion), medial collateral ligament sprain, lateral collateral ligament sprain and Baker’s cyst. There was good agreement between US and MRI in most of these pathologies. US showed an overall sensitivity of 61.7% and specificity of 92.7% with accuracy of 86.9%. The overall PPV and NPV were 66.1% and 91.3% respectively. Conclusion Ultrasound can be considered a reliable screening imaging modality in cases of knee pain.

A Novel Physical Examination Test for Ischiofemoral Impingement: Validation With Magnetic Resonance Imaging Correlation.

The purpose of this study was to propose and validate a novel physical examination test for ischiofemoral impingement with magnetic resonance imaging (MRI) correlation. We prospectively studied 24 women with buttock (deep gluteal) pain and 27 asymptomatic women. Each group underwent a 2-stage physical examination test that featured hip adduction-external rotation-extension and knee flexion. Visual analog scale pain scores were noted just before and during test stages on both sides. The MRI findings of the ischiofemoral impingement were evaluated quantitatively and qualitatively. Mean ages were 56.0 and 55.2 years (P = 0.797), and mean body mass indexes were 29.1 and 28.8 kg/m2 (P = 0.817) in symptomatic and asymptomatic groups, respectively. Ischiofemoral spaces were significantly narrower (P < 0.001), ischial angles were wider (P < 0.001, right; P = 0.002, left), and soft tissue edema at the ischiofemoral space was more common (P < 0.001) in the symptomatic group, which also had higher pretest visual analog scale scores (P < 0.001) that increased significantly during both upright standing (P = 0.003, right; P < 0.001, left) and recumbent (P < 0.001 for both sides) stages of the physical examination test. A novel physical examination test significantly increases symptoms of ischiofemoral impingement with positive MRI correlation.