Morphological Magnetic Resonance Imaging Research Articles

Assessment of Low-Grade Focal Cartilage Lesions in the Knee With Sodium MRI at 7 T: Reproducibility and Short-Term, 6-Month Follow-up Data.

Several articles have investigated potential of sodium (Na) magnetic resonance imaging (MRI) for the in vivo evaluation of cartilage health, but so far no study tested its feasibility for the evaluation of focal cartilage lesions of grade 1 or 2 as defined by the International Cartilage Repair Society. The aims of this study were to evaluate the ability of Na-MRI to differentiate between early focal lesions and normal-appearing cartilage, to evaluate within-subject reproducibility of Na-MRI, and to monitor longitudinal changes in participants with low-grade, focal chondral lesions. Thirteen participants (mean age, 50.1 ± 10.9 years; 7 women, 6 men) with low-grade, focal cartilage lesions in the weight-bearing region of femoral cartilage were included in this prospective cohort study. Participants were assessed at baseline, 1 week, 3 months, and 6 months using morphological MRI at 3 T and 7 T, compositional Na-MRI at 7 T, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Na signal intensities corrected for coil sensitivity and partial volume effect (Na-cSI) were calculated in the lesion, and in weight-bearing and non-weight-bearing regions of healthy femoral cartilage. Coefficients of variation, repeated measures analysis of covariance models, and Pearson correlation coefficients were calculated to evaluate within-subject reproducibility as well as cross-sectional and longitudinal changes in Na-cSI values. The mean coefficients of variation of Na-cSI values between the baseline and 1-week follow-up were 5.1% or less in all cartilage regions. Significantly lower Na-cSI values were observed in lesion than in weight-bearing and non-weight-bearing regions at all time points (all P values ≤ 0.002). Although a significant decrease from baseline Na-cSI values in lesion was found at 3-month visit (P = 0.015), no substantial change was observed at 6 months. KOOS scores have improved in all subscales at 3 months and 6 months visit, with a significant increase observed only in the quality of life subscale (P = 0.004). In vivo Na-MRI is a robust and reproducible method that allows to differentiate between low-grade, focal cartilage lesions and normal-appearing articular cartilage, which supports the concept that compositional cartilage changes can be found early, before the development of advanced morphological changes visible at clinical 3-T MRI.

Quistes pancreáticos: valor agregado de EUS-FNA sobre EUS y RMI. Experiencia de un hospital universitario de alta complejidad

Background. Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) are valuable tools in the assessment of cystic pancreatic lesions (CPLs). However, preoperative diagnosis of CPLs still remains a challenge. EUS-guided fine needle aspiration (FNA) provides a method to obtain cyst fluid for analysis to gain additional information. Aim. Compare the concordance between the diagnosis of the cyst by FNA, with that obtained by two diagnostic imaging methods (EUS morphology and MRI). Evaluate if EUS-FNA offered any benefit in cases of inconclusive MRI. Material and methods. We performed a retrospective analysis of a prospectively collected database at a tertiary-care academic medical center between January 2015 and December 2018. All patients who were referred for EUS were reviewed, and patients with diagnosis of pancreatic cysts were included. Imaging, pancreatic cyst fluid (PCF) and follow-up were analyzed. Results. A total of 2238 EUS were performed during the study period and 319 of them had a final diagnosis of pancreatic cyst. FNA was performed on 139 cysts: 62 were diagnosed as mucinous by PCF. The agreement between the diagnosis of the cyst by FNA, with that obtained by EUS morphology was 89.2% (Kappa 0.78, p < 0.001). The concordance between the diagnosis of the cyst by FNA and that obtained by MRI was 72.66 (Kappa 0.41, p < 0.001). From the 319 patients with pancreatic cysts, 60 (18.8%) had inconclusive results on MRI and EUS morphology was able to make a diagnosis in 31 of them. When we analyzed the 139 punctured cysts, MRI was indeterminate in 40 patients and FNA diagnosed 36 of the 40 patients (90%). Discussion. In our study, EUS +/- FNA was superior to MRI specially in cases of inconclusive MRI.

Magnetic resonance imaging features of minimal-fat angiomyolipoma and causes of preoperative misdiagnosis.

BACKGROUNDMinimal-fat angiomyolipoma (mf-AML) is often misdiagnosed as renal cell carcinoma before surgery.AIMTo analyze the magnetic resonance imaging (MRI) features of mf-AML and the causes of misdiagnosis by MRI before operation.METHODSA retrospective analysis was performed on ten patients with mf-AML confirmed by surgical pathology, all of whom underwent preoperative MRI examination to analyze the morphological characteristics and MRI signals of the tumor.RESULTSMRI revealed a circular-like mass in 4/10 (40%) patients, an oval mass in 6/10 patients (60%), a mass with a capsule in 9/10 patients (90%), and a mass with a lipid component in 7/10 patients (70%). The diameter of the masses in all ten patients was from 11 to 47 mm; the diameter was between 11 mm and 40 mm in 8/10 (80%) patients and between 40 mm and 47 mm in 2/10 (20%) patients.CONCLUSIONAn oval morphological characteristic is strong evidence for the diagnosis of mf-AML, while a capsule and lipids are atypical manifestations of mf-AML.

Associations between magnetic resonance imaging and EMG findings in myopathies.

Magnetic resonance imaging (MRI) is a cornerstone in diagnosis of myopathies. The present study sought to elucidate possible associations between electromyography (EMG) findings and histogram parameters derived from clinical MRI in myositis and other myopathies. Twenty six patients with myopathies were included in this retrospective study. Clinical MRI was performed with a 1.5T MRI scanner including T2- and T1-weighted images. EMG analysis was performed during clinical diagnostic workup. The histogram parameters of the MRI sequences were obtained of the same muscle, which was investigated with EMG. Several correlations were identified between mean duration of the motor unit potentials (MUP) and histogram parameters derived from T1- and T2-weighted images. The highest for T1-weighted images was mode (r= -.73, P<.0001) and for T2-weighted images was p25 (r=-.57, P=.022). There were significant differences for several histogram parameters between muscles with pathological spontaneous activity and without. So, for T1-weighted images, the best discrimination was achieved with mean (P=.096), and for T2-weighted images for p10 (P=.05). Mean SI values derived from T1-weighted images achieved an AUC of 0.84 with a sensitivity of 0.81 and a specificity of 0.86 to discriminate patients with and without pathological spontaneous activity (PSA). The present study identified strong associations between histogram analysis derived from morphological MRI sequences and the duration of the MUP derived from EMG in myopathies strengthening the fact that both diagnostic modalities can reflect disease state in a similar fashion. Histogram parameters can predict muscles with PSA.

Chondral and Osteochondral Femoral Cartilage Lesions Treated with GelrinC: Significant Improvement of Radiological Outcome Over Time and Zonal Variation of the Repair Tissue Based on T2 Mapping at 24 Months.

ObjectiveTo prospectively assess the efficacy of GelrinC in the treatment of chondral and osteochondral femoral cartilage lesions using morphological (Magnetic Resonance Observation of Cartilage Repair Tissue [MOCART]) and quantitative (T2-mapping) magnetic resonance imaging (MRI).DesignThis study was designed as a prospective single-arm, open label, multicenter study. Morphological magnetic resonance imaging (MRI) for MOCART assessment and T2 mapping was performed 1 week and 6, 12, 18, and 24 months after GelrinC implantation. Evaluation of T2 mapping was based on the assessment of global T2 indices (T2 of the repair tissue [RT] divided by T2 of healthy reference cartilage) and zonal variation.ResultsFifty-six (20 female) patients were prospectively enrolled. The mean MOCART score significantly increased from baseline to the 24-month follow-up with 88.8 (95% CI, 85.8-91.9; P < 0.001) for all lesions combined as well as 86.8 (95% CI, 83.0-90.6) for chondral lesions and 94.1 (95% CI, 68.55-100) for osteochondral lesions. Furthermore, based on T2 mapping, significant zonal variation of the RT was observed at 24 months (P = 0.039), which did not differ significantly from healthy reference cartilage (P = 0.6).ConclusionIncreasing MOCART scores were observed throughout the follow-up period, indicative of maturation of the cartilage repair. Significant zonal variation of the RT at 24 months might indicate the transformation into hyaline cartilage–like RT. Slightly differing morphological outcome between chondral and osteochondral lesions, but similar global and zonal T2 indices at 24 months, support the potential of GelrinC as a treatment option for both lesion types.

Morphological magnetic resonance imaging study of oral submucosal tissue and buccinator muscle dynamics in the posterior dentition: A clinical study

Statement of problemThe relationship between the buccal mucosa-tongue side wall contact points and at what ratio the submucosal tissue (ST) and buccinator muscle (BUC) change during function are unclear. PurposeThe purpose of this clinical study was to clarify the space and dynamics of the ST and BUC in complete denture wearers by using magnetic resonance imaging and to investigate how denture base shape affects space sealing and the relationship between the ST and BUC. Material and methodsEight edentulous participants wearing maxillary and mandibular complete dentures were enrolled. Wax was added to the buccal border of the dentures, and axial and coronal magnetic resonance imaging scans were made during mandibular rest (MR) to observe the relationship of the buccal mucosa and tongue above the retromolar pads. In addition, on axial images, the thicknesses of the ST and BUC were measured at 3 sites: second molar center, second molar distal (SMD), and retromolar pad center (RPC). Coronal images were made during MR, partial mouth opening, and midmouth opening (MMo). At second molar center, SMD, and RPC, the thicknesses of the ST and BUC were measured at the maxillary buccinator attachment region (point A), the mandibular buccinator attachment region (point B), and the median point between A and B (point M). ResultsDuring MR, contact sealing of the buccal mucosa and tongue on the RPC was noted in 81% of participants. After expanding the denture base with wax, contact was lost in 86% of participants. The ST and BUC thicknesses on the RPC decreased significantly with the addition of wax. During MR, the ST became significantly thicker the further posteriorly it was located. The ST was significantly thicker at point M than at point A for all sections, regardless of mouth opening. The ST and BUC thicknesses in SMD and RPC were significantly thicker at point M than at point B during MR and MMo. The differences of the ST and BUC thicknesses depending on the opening amount were observed only at the point M. In the RPC, the thickness of the ST and BUC decreased significantly as the opening amount increased (ST thickness between MR and partial mouth opening, MR, and MMo: P=.007, P=.001, BUC: P=.018, P=.001, respectively) ConclusionsThe thickness of the ST and BUC differed depending on the site. During mouth opening, these changes in thickness at each site are proportional to the differences in ST and BUC thickness.

Diffusion-weighted magnetic resonance imaging in the characterization of odontogenic cysts and tumors

The aim of this study was to evaluate diffusion-weighted imaging (DWI) in comparison with morphologic magnetic resonance imaging (MRI) in differentiating among odontogenic keratocyst (OKC), unicystic ameloblastoma (UAB), and dentigerous cyst (DC). Contrast-enhanced MRI, including DWI, was performed on 27 patients with the 3 lesions. Signal intensity characteristics were evaluated on T1- and T2-weighted MRI. The apparent diffusion coefficient (ADC) cutoff value to most effectively differentiate among the 3 lesions was calculated with receiver operating characteristic analysis. In total, 17 OKCs, 5 UABs, and 5 DCs were diagnosed histologically. There were no significant differences among them in signal intensity on T1- or T2-weighted images (P ≥ .13). On DWI, 14 of 17 OKCs showed restricted diffusion with a mean ADC value of 0.954 × 10-3 mm2/s. All 5 UABs and all 5 DCs exhibited facilitated diffusion with ADC values ≥ 2.150 × 10-3 mm2/s. The ADC cutoff to differentiate OKCs from UABs was 2.137 × 10-3 mm2/s (P = .01); UABs from DCs was 2.422 × 10-3 mm2/s (P = .03); and OKCs from DCs was 2.347 × 10-3 mm2/s (P = .01). Addition of diffusion-weighted sequences to MRI jaw protocols can assist in the characterization of OKCs, UABs, and DCs.

Assessment of Articular Cartilage Disorders After Distal Radius Fracture Using Biochemical and Morphological Nonenhanced Magnetic Resonance Imaging

To assess radiocarpal articular cartilage after distal radius fracture, with and without intra-articular extension, compared with healthy controls using multiparametric, nonenhanced magnetic resonance imaging (MRI). In this prospective study, multiparametric MRI of the radiocarpal articular cartilage was performed in 26 participants (16 males and 10 females; mean age, 39.5 ± 14.7 years; range, 20-70 years) using 3T MRI. The cohort consisted of 14 patients with a distal radius fracture and 12 healthy volunteers. The radiocarpal articular cartilage was assessed using morphological (Double Echo Steady-State [DESS] and True Fast Imaging With Steady-State Precession [TrueFISP]) and biochemical (T2∗) MRI sequences without an intravenous contrast agent. The modified Outerbridge classification system for morphological analyses and region-of-interest biochemical analysis were applied to assess the degree of articular cartilage damage in each patient. Morphological articular cartilage assessment showed no difference between the DESS sequence and the reference standard, TrueFISP. In the morphological (DESS and TrueFISP) and biochemical (T2∗) assessments, patients with intra-articular fractures did not show articular cartilage damage different from those with extra-articular fractures. Greater articular cartilage degradation was observed after distal radius fracture compared with controls. Posttraumatic radiocarpal articular cartilage damage did not differ between fractures with intra-articular and extra-articular extension, but patients with fractures had notably higher articular cartilage degradation compared with healthy controls. Magnetic resonance imaging using advanced multiparametric sequences may facilitate accurate, noninvasive assessment of articular cartilage changes after distal radius fracture without the need for a contrast agent. Diagnostic IV.

MRI Features of the Vomeronasal Organ in Dogs (Canis Familiaris).

According to current knowledge, the vomeronasal organ (VNO, Jacobson's organ) is the structure responsible for semiochemical signal detection. In dogs and other mammals, it is located close to the vomer and palatine processes of the incisive and maxillary bones. Although there are reports describing the anatomy and histology of this structure, there are limited available reports assessing this organ in live individuals and no direct visualization reports in dogs. The aim of this study was 2-fold: (1) preparation and optimization of a protocol for magnetic resonance imaging (MRI) examination of the VNO in a cadaver study with precise visualization and localization, and (2) characterization of the physiological VNO image features in MRI of live dogs. The first part of the study was performed on 10 beagle cadavers, the second on 8 live beagle dogs. For the VNO visualization, a 1.5T MRI (Philips® Ingenia) scanner and 20-channel digital head-neck spine coil were used (Philips®, Holland). The cadaver study allowed confirmation of the organ's location by the topical application of an MRI contrast agent (gadolinium) via the external entrance of the VNO canal. Accurate delineation of the VNO was obtained using a high resolution submillimeter three-dimensional T1-fast field echo (FFE) 3D sequence. Imaging of the VNO in 8 living dogs allowed the description of the morphological MRI features and direct evaluation of its shape and size. The results obtained demonstrate the ability to visualize the VNO in vivo and to evaluate its structure in dogs.

Multivariate use of MRI biomarkers to classify histologically confirmed necrosis in symptomatic total hip arthroplasty.

The failure of total hip arthroplasty (THA) is commonly associated with the necrosis of the periprosthetic tissue. To date, there is no established method to noninvasively quantify the progression of such necrosis. Magnetic resonance imaging (MRI) of soft tissues near implants has undergone a recent renaissance due to the development of multispectral metal-artifact reduction techniques. Advanced analysis of multispectral MRI has been shown capable of detecting small magnetism effects of metallic debris in periprosthetic tissue. The purpose of this study is to demonstrate the diagnostic utility of these MRI-based tissue-magnetism signatures. Together with morphological MRI metrics, such as synovial volume and thickness, these measurements are utilized as biomarkers to noninvasively detect soft-tissue necrosis in symptomatic THA patients ( ). All subjects underwent an advanced MRI scan before revision surgery and tissue biopsies utilized for necrosis grading. Statistical analyses demonstrated a weak, but significant positive correlation (P = .04) between MRI magnetism signatures and necrosis scores, while indicating no meaningful association between the latter and serum cobalt and chromium ion levels. Receiver-operating characteristic (ROC) analyses were then performed based on uni- and multivariate logistic regression models utilizing the measured MRI biomarkers as predictors of severe necrosis. The area under the curve of the ROC plots for MRI biomarkers as combined predictors were found to be 0.70 and 0.84 for cross-validation and precision-recall tests, respectively.

Assessment of an scFv Antibody Fragment Against ELTD1 in a G55 Glioblastoma Xenograft Model

Glioblastoma (GBM), the most common primary brain tumor found in adults, is extremely aggressive. These high-grade gliomas, which are very diffuse, highly vascular, and invasive, undergo unregulated vascular angiogenesis. Despite available treatments, the median survival for patients is dismal. ELTD1 (EGF, latrophilin, and 7 transmembrane domain containing protein 1) is an angiogenic biomarker highly expressed in human high-grade gliomas. Recent studies have demonstrated that the blood-brain barrier, as well as the blood-tumor barrier, is not equally disrupted in GBM patients. This study therefore aimed to optimize an antibody treatment against ELTD1 using a smaller scFv fragment of a monoclonal antibody that binds against the external region of ELTD1 in a G55 glioma xenograft glioma preclinical model. Morphological magnetic resonance imaging (MRI) was used to determine tumor volumes and quantify perfusion rates. We also assessed percent survival following tumor postdetection. Tumor tissue was also assessed to confirm and quantify the presence of the ELTD1 scFv molecular targeted MRI probe, as well as microvessel density and Notch1 levels. In addition, we used molecular-targeted MRI to localize our antibodies in vivo. This approach showed that our scFv antibody attached-molecular MRI probe was effective in targeting and localizing diffuse tumor regions. Through this analysis, we determined that our anti-ELTD1 scFv antibody treatments were successful in increasing survival, decreasing tumor volumes, and normalizing vascular perfusion and Notch1 levels within tumor regions. This study demonstrates that our scFv fragment antibody against ELTD1 may be useful and potential antiangiogenic treatments against GBM.

Morphological MRI of knee cartilage: repeatability and reproducibility of damage evaluation and correlation with gross pathology examination.

To assess the performance of a morphological evaluation, based on a clinically relevant magnetic resonance imaging (MRI) protocol, in scoring the severity of knee cartilage damage. Specifically, to evaluate the reproducibility, repeatability, and agreement of MRI evaluation with the gross pathology examination (GPE) of the tissue. MRI of the knee was performed the day before surgery in 23 patients undergoing total knee arthroplasty. Osteochondral tissue resections were collected and chondral defects were scored by GPE according to a semi-quantitative scale. MR images were independently scored by four radiologists, who assessed the severity of chondral damage according to equivalent criteria. Inter- and intra-rater agreements of MRI evaluations were assessed. Correlation, precision, and accuracy metrics between MRI and GPE scores were calculated. Moderate to substantial inter-rater agreement in scoring cartilage damage by MRI was found among radiologists. Intra-rater agreement was higher than 96%. A significant positive monotonic correlation between GPE and MRI scores was observed for all radiologists, although higher correlation values were obtained by radiologists with expertise in musculoskeletal radiology and/or longer experience. The accuracy of MRI scores displayed a spatial pattern, characterized by lesion overestimation in the lateral condyle and underestimation in the medial condyle with respect to GPE. Evaluation of knee cartilage morphology by MRI is a reproducible and repeatable technique, which positively correlates with GPE. Clinical expertise in musculoskeletal radiology positively impacts the evaluation reliability. These findings may help to address limitations in MRI evaluation of knee chondral lesions, thus improving MRI assessment of knee cartilage. • MRI evaluation of knee cartilage shows moderate to strong correlation with gross pathology examination. • MRI evaluation overestimates cartilage damage in the lateral condyle and underestimates it in the medial condyle. • Education and experience of the radiologist play a role in MRI evaluation of knee chondral lesions.

Hemoglobin-mediated biomimetic synthesis of paramagnetic O2-evolving theranostic nanoprobes for MR imaging-guided enhanced photodynamic therapy of tumor.

The hypoxic microenvironment in solid tumors severely limits the efficacy of photodynamic therapy (PDT). Therefore, the development of nanocarriers co-loaded with photosensitizers and oxygen, together with imaging guidance ability, is of great significance in cancer therapy. However, previously reported synthetic methods for these multi-functional probes are complicated, and the raw materials used are toxic.Methods: Herein, the human endogenous protein, hemoglobin (Hb), was used for the simultaneous biomimetic synthesis of Gd-based nanostructures and co-loading of Chlorine e6 (Ce6) and oxygen for alleviating the hypoxic environment of tumors and accomplishing magnetic resonance imaging (MRI)-guided enhanced PDT. The Gd@HbCe6-PEG nanoprobes were synthesized via a green and protein biomimetic approach. The physicochemical properties, including relaxivity, oxygen-carrying/release capability, and PDT efficacy of Gd@HbCe6-PEG, were measured in vitro and in vivo on tumor-bearing mice after intravenous injection. Morphologic and functional MRI were carried out to evaluate the efficacy of PDT.Results: The results demonstrated the successful synthesis of compact Gd@HbCe6-PEG nanostructures with desired multi-functionalities. Following treatment with the nanoparticles, the embedded MR moiety was effective in lighting tumor lesions and guiding therapy. The oxygen-carrying capability of Hb after biomimetic synthesis was confirmed by spectroscopic analysis and oxygen detector in vitro. Further, tumor oxygenation for alleviating tumor hypoxia in vivo after intravenous injection of Gd@HbCe6-PEG was verified by photoacoustic imaging and immunofluorescence staining. The potent treatment efficacy of PDT on early-stage was observed by the morphologic and functional MR imaging. Importantly, rapid renal clearance of the particles was observed after treatment.Conclusion: In this study, by using a human endogenous protein, we demonstrated the biomimetic synthesis of multi-functional nanoprobes for simultaneous tumor oxygenation and imaging-guided enhanced PDT. The therapeutic efficacy could be quantitatively confirmed at 6 h post PDT with diffusion-weighted imaging (DWI).

Les modifications morphologiques IRM d’un ligament croisé antérieur sont liées à l’augmentation de la pente tibiale médiale après ostéotomie proximale tibiale d’ouverture médiale

BackgroundMedial opening wedge high tibial osteotomy (OWHTO) is a useful treatment for medial osteoarthritis. However, OWHTO sometimes causes a change in tibial slope in the sagittal plane. Although several studies have described the effects of the tibial slope on the biomechanics of the knee, including the anterior cruciate ligament (ACL), there has been little study of the magnetic resonance imaging (MRI) visible changes occurring to the native ACL and the factors affecting them after OWHTO. HypothesisWe hypothesized that morphologic MRI changes to an uninjured ACL after OWHTO would be associated with increased medial tibial plateau bony slope. Patients and methodsThirty-three patients who underwent OWHTO and pre/postoperative MRI were included in this retrospective study. The mean period of follow-up MRI was 22.35 (±14.78) months. The patients were divided into two groups according to the occurrence of postoperative ACL morphologic MRI changes defined as mucoid degeneration, ganglion cyst occurrence, or change in the ACL fiber shape (stationary group n=21, altered group n=12). The medial tibial plateau bony slope (MTS) and anterior tibial translation (ATT) were evaluated on MRI. Logistic regression analysis was used to determine factors affecting the occurrence of postoperative ACL morphologic changes. ResultsPostoperative MTS and the difference between pre- and post values (ΔMTS), postoperative ATT and the difference between pre- and post values (ΔATT) were significantly different between stationary and altered groups. ΔMTS was associated with postoperative morphologic changes to the ACL (odds ratio: 0.30, 95% confidence interval=0.11–0.82, p=0.019). ConclusionThe occurrence of morphologic ACL change after OWHTO is associated with the amount of MTS change. Level of evidenceIII, retrospective comparative study.

Comparison of proton density fat fraction, simultaneous R2*, and apparent diffusion coefficient for assessment of focal vertebral bone marrow lesions

To investigate the diagnostic performance of proton density fat fraction (PDFF) and simultaneous R2* for focal vertebral bone marrow lesion (VBML) assessment, compared with the apparent diffusion coefficient (ADC). One hundred and ninety-two spinal magnetic resonance imaging (MRI) examinations performed in 126 patients with focal VBMLs from March 2016 to November 2018 were reviewed retrospectively. The lesions were divided into metastases and benign VBMLs. The protocol consisted of routine morphological MRI sequences, followed by complex-based chemical shift imaging (CSE)-MRI and diffusion-weighted (DW)-MRI with a 1.5 T system. PDFF, R2*, and the ADC values were compared using the Mann-Whitney U-test. Receiver operating characteristic curve analysis was carried out to assess the diagnostic performance for differentiating metastases from focal benign VBMLs. PDFF, R2*, and mean ADC values in metastases were significantly lower than those in benign VBMLs (p<0.05). The PDFF (area under the curve [AUC]= 0.968; 95% confidence interval [CI]=0.932-0.988) showed a significantly larger AUC compared with R2* (AUC=0.670; 95% CI=0.599-0.736) and ADC (AUC=0.801; 95% CI=0.738-0.855). The optimal cut-off value of the PDFF for predicting metastases was 9%; this threshold corresponded to a sensitivity of 96.67%, specificity of 90.28%, and accuracy of 94.27%. PDFF is significantly more accurate than ADC and R2* for differentiating focal benign VMBLs from metastases.

Does Injection of Hyaluronic Acid Protect Against Early Cartilage Injury Seen After Marathon Running? A Randomized Controlled Trial Utilizing High-Field Magnetic Resonance Imaging

Background: Previous studies have shown that runners demonstrate elevated T2 and T1ρ values on magnetic resonance imaging (MRI) after running a marathon, with the greatest changes in the patellofemoral and medial compartment, which can persist after 3 months of reduced activity. Additionally, marathon running has been shown to increase serum inflammatory markers. Hyaluronic acid (HA) purportedly improves viscoelasticity of synovial fluid, serving as a lubricant while also having chondroprotective and anti-inflammatory effects. Purpose/Hypothesis: The purpose was to investigate whether intra-articular HA injection can protect articular cartilage from injury attributed to marathon running. The hypothesis was that the addition of intra-articular HA 1 week before running a marathon would reduce the magnitude of early cartilage breakdown measured by MRI. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: After institutional review board approval, 20 runners were randomized into receiving an intra-articular injection of HA or normal saline (NS) 1 week before running a marathon. Exclusionary criteria included any prior knee injury or surgery and having run >3 prior marathons. Baseline 3-T knee MRI was obtained within 48 hours before the marathon (approximately 5 days after injection). Follow-up 3-T MRI scans of the same knee were obtained 48 to 72 hours and 3 months after the marathon. The T2 and T1ρ relaxation times of articular cartilage were measured in 8 locations—the medial and lateral compartments (including 2 areas of each femoral condyle) and the patellofemoral joint. The statistical analysis compared changes in T2 and T1ρ relaxation times (ms) from baseline to immediate and 3-month postmarathon scans between the HA and NS groups with repeated measures analysis of variance. Results: Fifteen runners completed the study: 6 women and 2 men in the HA group (mean age, 31 years; range, 23-50 years) and 6 women and 1 man in the NS group (mean age, 27 years; range, 20-49 years). There were no gross morphologic MRI changes after running the marathon. Postmarathon studies revealed no statistically significant changes between the HA and NS groups in all articular cartilage areas of the knee on both T2 and T1ρ relaxation times. Conclusion: Increased T2 and T1ρ relaxation times have been observed in marathon runners, suggesting early cartilage injury. The addition of intra-articular HA did not significantly affect relaxation times in all areas of the knee when compared with an NS control.

Morphologic MRI changes of the anterior cruciate ligament are associated with an increase in the medial tibial plateau bony slope after medial opening wedge high tibial osteotomy in a non-injured ACL population

BackgroundMedial opening wedge high tibial osteotomy (OWHTO) is a useful treatment for medial osteoarthritis. However, OWHTO sometimes causes a change in tibial slope in the sagittal plane. Although several studies have described the effects of the tibial slope on the biomechanics of the knee, including the anterior cruciate ligament (ACL), there has been little study of the magnetic resonance imaging (MRI) visible changes occurring to the native ACL and the factors affecting them after OWHTO. HypothesisWe hypothesized that morphologic MRI changes to an uninjured ACL after OWHTO would be associated with increased medial tibial plateau bony slope. Patients and MethodsThirty-three patients who underwent OWHTO and pre/postoperative MRI were included in this retrospective study. The mean period of follow-up MRI was 22.35 (±14.78) months. The patients were divided into two groups according to the occurrence of postoperative ACL morphologic MRI changes defined as mucoid degeneration, ganglion cyst occurrence, or change in the ACL fiber shape (stationary group n=21, altered group n=12). The medial tibial plateau bony slope (MTS) and anterior tibial translation (ATT) were evaluated on MRI. Logistic regression analysis was used to determine factors affecting the occurrence of postoperative ACL morphologic changes. ResultsPostoperative MTS and the difference between pre- and post values (ΔMTS), postoperative ATT and the difference between pre- and post values (ΔATT) were significantly different between stationary and altered groups. ΔMTS was associated with postoperative morphologic changes to the ACL (odds ratio: 0.30, 95% confidence interval=0.11–0.82, p=0.019). ConclusionThe occurrence of morphologic ACL change after OWHTO is associated with the amount of MTS change. Level of EvidenceIII, Retrospective comparative study.

A New Method for Cartilage Evaluation in Femoroacetabular Impingement Using Quantitative T2 Magnetic Resonance Imaging: Preliminary Validation against Arthroscopic Findings.

The outcome of arthroscopic treatment for femoroacetabular impingement (FAI) depends on the preoperative status of the hip cartilage. Quantitative T2 can detect early biochemical cartilage changes, but its routine implementation is challenging. Furthermore, intrinsic T2 variability between patients makes it difficult to define a threshold to identify cartilage lesions. To address this, we propose a normalized T2-index as a new method to evaluate cartilage in FAI. We retrospectively analyzed magnetic resonance imaging (MRI) data of 18 FAI patients with arthroscopically confirmed cartilage defects. Cartilage T2 maps were reconstructed from multi-spin-echo 3-T data using the echo-modulation-curve (EMC) model-based technique. The central femoral cartilage, assumed healthy in early-stage FAI, was used as the normalization reference to define a T2-index. We investigated the ability of the T2-index to detect surgically confirmed cartilage lesions. The average T2-index was 1.14 ± 0.1 and 1.13 ± 0.1 for 2 separated segmentations. Using T2-index >1 as the threshold for damaged cartilage, accuracy was 88% and 100% for the 2 segmentations. We found moderate intraobserver repeatability, although separate segmentations yielded comparable accuracy. Damaged cartilage could not be identified using nonnormalized average T2 values. This preliminary study confirms the importance of normalizing T2 values to account for interpatient variability and suggests that the T2-index is a promising biomarker for the detection of cartilage lesions in FAI. Future work is needed to confirm that combining T2-index with morphologic MRI and other quantitative biomarkers could improve cartilage assessment in FAI.

Morphological MRI investigations of the hypothalamus in 232 individuals with Parkinson's disease.

The pathophysiology of the hypothalamic involvement in Parkinson's disease (PD) is not well understood. The objective of this study was the quantification of hypothalamic volumes in vivo in PD. High-resolution T1 -weighted magnetic resonance imaging (MRI) data from 232 individuals with PD and 130 healthy non-PD individuals were used for quantification of the hypothalamic volumes. The hypothalamus in PD was not atrophied, as indicated by volumetric analyses in the prospectively collected subcohort (30 PD, V = 921 ± 78 mm3 vs 30 non-PD, V = 917 ± 67 mm3 ; P = 0.850) and validated in a large cohort (202 PD, V = 925 ± 88 mm3 vs 100 non-PD, V = 932 ± 114 mm3 ; P = 0.602). Hypothalamic involvement in PD as shown by a large body of histopathological evidence does not appear to be detectable by MRI-based volumetric quantification. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Texture analysis parameters derived from T1-and T2-weighted magnetic resonance images can reflect Ki67 index in soft tissue sarcoma

Background and objectivesTexture analysis derived from morphological magnetic resonance (MR) images might be associated with histopathology in tumors. The present study sought to elucidate possible associations between texture features derived from T1-and T2-weighted images with proliferation index Ki67 in soft tissue sarcomas. MethodsOverall, 29 patients (n = 13, 44.8% female) with a median age of 52 years were included into this retrospective study. Several soft tissue sarcomas were investigated. Texture analysis was performed on pre-contrast T1-weighted and T2-weighted images using the free available Mazda software. ResultsThe best correlation coefficients with Ki67 index were identified for the following parameters: T1-weighted images “45dgr_RLNonUni (p = 0.50, P = 0.006), T2-weighted images “S (4,0)SumAverg” (p = −0.45, P = 0.02). A ROC analysis was performed for Ki67-index with a threshold of 10%. The highest area under the curve (AUC) was found for the parameter “T1_WavEnHL_s-7” with an AUC of 0.90. For the threshold of Ki67 = 20% the highest AUC was identified for the parameter „T2_S (1,1)Entropy” with an AUC of 0.77. ConclusionSeveral texture features derived from T1-and T2-weighted images correlated with proliferation index Ki67 and might be used as valuable novel biomarkers in soft tissue sarcomas.