Planar Magnetic Resonance Imaging Research Articles

Evaluation of healing after arthroscopic repair of lateral meniscal tears around the popliteal hiatus

BackgroundThe popliteal hiatus stabilizes the lateral meniscus (LM). Variable failure rates for LM repairs have been reported in knees with lateral meniscal tears (LMTs), which may be attributable to low vascularity around the popliteal hiatus. An effective repair method is essential to enhance the biological healing and stability of LMTs around the popliteal hiatus. HypothesisArthroscopic repair of LMTs, including the popliteus tendon around the popliteal hiatus, is expected to produce a low reoperation rate and effective treatment, both clinically and radiographically. Material and methodsFrom June 2011 to August 2020, 93 patients (mean age 27.9 ± 13.5 years) who underwent arthroscopic repair of LMTs including the popliteus tendon around the popliteal hiatus were enrolled. Patients with LMTs were divided into three groups: isolated LMTs, discoid LMTs, and LMTs with ACL injury. Patients had a minimum clinical follow-up of 2 years (mean 37.9 ± 19.3 months) and Tegner activity, Lysholm knee, and Hospital for Special Surgery (HSS) scores were evaluated for all patients. The widths of the popliteal hiatus and LM extrusion were measured on the sagittal and coronal planes using preoperative and postoperative magnetic resonance imaging (MRI). ResultsThe Tegner activity (2.6 ± 1.2 to 4.5 ± 1.3), Lysholm (67.9 ± 14.2 to 88.1 ± 6.4), and HSS scores (79.8 ± 11.5 to 93.7 ± 5.1) were significantly improved in all knees (p < 0.001). The width of the popliteal hiatus measured on MRI was significantly decreased, when comparing the preoperative and postoperative MRI for all knees (sagittal plane, 2.9 ± 1.4 to 1.5 ± 0.5 mm; coronal plane, 3.8 ± 2.5 to 1.9 ± 1.0 mm) (p < 0.05). The LM extrusion measured on the sagittal plane of postoperative MRI was also significantly reduced after arthroscopic repair (24.8 ± 3.1 to 23.7 ± 2.8 mm) (p = 0.001). Five reoperations (5/93, 5.3%) were performed, suggesting a clinical failure. ConclusionArthroscopic repair of isolated, discoid and post-traumatic LMTs including the popliteus tendon around the popliteal hiatus, is an effective surgical treatment for LM stabilization. Level of evidenceLevel IV, retrospective series.

Balancing Anterior and Posterior Cruciate Ligaments in Adults.

The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) represent the central pivot of the knee. The balance between these two ligaments impacts the tibiofemoral biomechanics. Each structure is the opposite of the other in terms of anteroposterior translation and rotation. The aimof this study was to find a correlation between the cross-sectional area of the ACL and PCL in adults. Magnetic resonance imaging (MRI) data analysis was conducted by a musculoskeletal radiologist using MRI planes tailored to the study's requirements. In all 62 studied patients, measurements were done according to the protocol. The study observed three types of intercondylar notches: Type U was identified in 35% (22) of patients, type W in 27% (17), and type A in 37% (23). The median difference between the ACL and PCL areas was found to be statistically significant (p = 0.02). A significant difference in the area of the ACL was detected between Type A and Type U notches (p = 0.02), while no significant differences were found between Type A-W and Type W-U after post hoc corrections (p > 0.05). Additionally, no significant difference was observed in the mean area of the PCL across all three notch types (p = 0.1). In 68% of the cases, the ACL is no less than 60% of the PCL in area, and no more than 120%. The size of ACL and PCL in healthy individuals also depends on other factors like synergistic and antagonistic muscle activities, occupation, and the hip-knee-ankle axis. For example, if the PCL area is 0.79 cm² and the measured structure is round (during a reconstruction a hamstring graft is round), the diameter is 10 mm. A native ACL is, in 68% of the cases, no less than 7.7 mm, and no more than 10.9 mm. The ACL-PCL size correlation helps in understanding the balance of the central pivot of the knee.

Model-based iterative reconstruction for direct imaging with point spread function encoded echo planar MRI

BackgroundEcho planar imaging (EPI) is a fast measurement technique commonly used in magnetic resonance imaging (MRI), but is highly sensitive to measurement non-idealities in reconstruction. Point spread function (PSF)-encoded EPI is a multi-shot strategy which alleviates distortion, but acquisition of encodings suitable for direct distortion-free imaging prolongs scan time. In this work, a model-based iterative reconstruction (MBIR) framework is introduced for direct imaging with PSF-EPI to improve image quality and acceleration potential. MethodsAn MBIR platform was developed for accelerated PSF-EPI. The reconstruction utilizes a subspace representation, is regularized to promote local low-rankedness (LLR), and uses variable splitting for efficient iteration. Comparisons were made against standard reconstructions from prospectively accelerated PSF-EPI data and with retrospective subsampling. Exploring aggressive partial Fourier acceleration of the PSF-encoding dimension, additional comparisons were made against an extension of Homodyne to direct PSF-EPI in numerical experiments. A neuroradiologists' assessment was completed comparing images reconstructed with MBIR from retrospectively truncated data directly against images obtained with standard reconstructions from non-truncated datasets. ResultsImage quality results were consistently superior for MBIR relative to standard and Homodyne reconstructions. As the MBIR signal model and reconstruction allow for arbitrary sampling of the PSF space, random sampling of the PSF-encoding dimension was also demonstrated, with quantitative assessments indicating best performance achieved through nonuniform PSF sampling combined with partial Fourier. With retrospective subsampling, MBIR reconstructs high-quality images from sub-minute scan datasets. MBIR was shown to be superior in a neuroradiologists' assessment with respect to three of five performance criteria, with equivalence for the remaining two. ConclusionsA novel image reconstruction framework is introduced for direct imaging with PSF-EPI, enabling arbitrary PSF space sampling and reconstruction of diagnostic-quality images from highly accelerated PSF-encoded EPI data.

Content-aware Nakagami morphing for incremental brain MRI

Within the carcinogenesis mechanism, from the initiation of the very first tumor cell to the preneoplastic and neoplastic cancer cell groups, cancer cells omnidirectionally and unpredictably proliferate in three-dimensional (3D) space during the promotion and progression steps. Whole tumors areas, consisting of edema, necrosis, enhancing and non-enhancing tumor subareas, could easily be identified by the typical sequences of magnetic resonance imaging (MRI), mostly by FLAIR, the fluid attenuated inversion recovery sequence. Depending on the increment value of the scanner, not every scan could be contiguous though, which might create some gaps between the slices and cause some crucial loss of information. Shape-based morphing by erosion and dilation operations might be inadequate when the source or target lesions are not found on the MRI slices, which might emerge due to unpredictable shape of tumors. Furthermore, the real trajectories and genuine shapes of the tumors in spatial view might not be seen in the planar MRI slices due to approximations during the voxel-to-pixel transformations executed in MRI devices. Therefore, we propose a novel content-aware morphing procedure to generate imaginary slices by m-parametric Nakagami imaging. The mathematical and parametric design in our framework not only leads to precise segmentation of the whole tumors according to the ground truth images; but also, to realistic morphing, based on the content of tumor footprints in MRI slices. For testing purposes, a total number of 5133 morphs are created using 1831 genuine images containing at least one lesion taken from the Brats 2012 dataset. Given the average dice score coefficients (DSC), we obtained an average of 88.44% DSC with our morphing framework outperforming the conventional dilation-based morphing result which is 83.25%. Besides being a novel morphing methodology, the outcomes of this research could also be very beneficial in smoother 3D reconstruction and more realistic volumetric calculations of lesions to help the experts working on assessment of lesions.

Radial Planes in Hip Magnetic Resonance Imaging: Techniques, Applications, and Perspectives.

The hip cartilage and labrum, as the main targets of femoroacetabular impingement, sports-related or traumatic damage, as well as congenital and developmental abnormalities, have attracted increasing attention with the development of magnetic resonance imaging (MRI) and hip arthroscopy. MRI is a commonly used imaging modality to noninvasively visualize the hip cartilage and labral lesions. However, conventional orthogonal MRI planes encounter unique challenges given the ball-and-socket configuration of the hip joint, its anatomically abducted and anteverted orientation, and the thin, closely apposed cartilage enveloping the femoral head and acetabulum. Advancements in hip MRI's radial plane, which is acquired through the center of the hip joint, offer a solution. This technology provides true cross-sectional images of the cartilage and labrum perpendicular to the curvature of the joint, thereby mitigating the partial-volume-averaging effects. The integration of 3.0-Tesla high field strength and three-dimensional (3D) acquisition techniques further enhances the capabilities of the radial plane. This combination yields a high signal-to-noise ratio, high spatial resolution, high contrast between intraarticular structures, while minimizing partial-volume-averaging effects. Such improvements potentially facilitate the comprehensive detection of even minor chondral and labral lesions. The capability for multiplanar reconstruction from a single 3D volumetric acquisition further strengthens the usefulness of the radial plane by aiding in precise localization of hip cartilage and labral lesions, in line with hip arthroscopy findings. These advancements have the potential to standardize MRI evaluations and radiographic reporting systems for hip cartilage and labrum, offering precise guidance for hip arthroscopy. This article presents a comprehensive review of radial plane technology applied to the hip MRI, and discusses the morphological assessment and localization of hip cartilage and labral lesions utilizing this advanced imaging technique. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

Cubonavicular Coalition: Magnetic Resonance Imaging Findings and Associated Pathology of a Rarely Reported Condition in 27 Patients

(1) Describe multimodality imaging of cubonavicular coalition (CNC) with magnetic resonance imaging (MRI) focus, (2) evaluate CNC associated foot and ankle pathology, (3) examine clinical presentation/symptoms associated with CNC, (4) record CNC treatment. Retrospective Institutional Review Board (IRB) approved study. Picture Archiving and Communication System (PACS) databases searched for CNC. Final study population: 34 cases in 27 patients. Each CNC was reviewed for: coalition type (osseous versus non-osseous- cartilaginous versus fibrous), tendon and ligament pathology, bone marrow edema at CNC and adjacent joints, presence and severity of degenerative changes at CNC and adjacent joints, fractures, additional coalitions, laterality, and pes planus. MRI planes and radiographic views on which coalitions were best identified were recorded. Each CNC EMR was reviewed for: symptoms, trauma, management, patient demographics. Inter-reader reliability was performed for type of non-osseous coalition. Final cohort included 34 cases in 27 patients (average age: 34.7, range: 10-76; 71% female). No CNC was completely osseous. On MRI, 89.5% of coalitions were non-osseous and 5.3% were partially osseous. 76.5% of patients had referable symptoms including pain, limited motion, inability to bear weight. 23.5% of patients were surgically managed/pathologically proven. On MRI, 36.8% of patients had tendon pathology, 52.6% had ligamentous pathology, 100% had bone marrow edema-like signal abnormality about the CNC, and 88.2% had CNC degenerative changes. There was bone marrow edema-like signal abnormality at bones adjacent to the CNC in 52.6% and adjacent joint degenerative disease present in 50%. CNC was best identified on oblique radiographs and axial MRI. Inter-reader reliability for non-osseous coalition type was poor, Cronbach's alpha 0.554. CNC is subtle and findings of osteoarthritis or bone marrow edema-like about the cubonavicular articulation should raise suspicion for underlying coalition.

Association of Internal and External Motion Based on Cine MR Images Acquired During Real-Time Treatment on MRI–Guided Linear Accelerator for Patients With Lung Cancer

With the recent clinical implementation of magnetic resonance imaging (MRI)-guided linear accelerators, a large number of real-time planar MR images has been acquired during lung cancer treatment as a standard of care. In this study, associations among lung tumor, diaphragm, and external skin movement were studied based on MR cine imaging during the entire duration of each treatment fraction. This retrospective study used 181,798 planar MRI frames acquired over 55 treatment/imaging sessions of 13 patients with lung cancer treated on 2 MRI-guided linear accelerators. From each planar MR image frame, in-house software automatically extracted 9 features: the superior-interior (SI) and posterior-anterior (PA) positions of a lung tumor; the area of the lung (Lung_Area); the posterior (Dia_Post), dome/apex (Dia_Dome), and anterior (Dia_Ant) points of a diaphragmatic curve; the diaphragm curve point (Dia_Max); and the chest (Chest) and belly (Belly) skin points experienced the maximum range of motions. Correlation analyses were performed among the 9 features for every session. Lung tumor motion range and standard deviations were calculated based on positions obtained in cine images and compared with motion ranges obtained from 4-dimensional computed tomography images. In the study, 177,009 frames of images were successfully analyzed. For all patients, correlation coefficients were as follows: 0.91 ± 0.10 between any 2 features among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.82 ± 0.21 between SI and any feature among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.75 ± 0.24 between SI and Belly. Six of 13 patients were considered large amplitude motion (patients with lung tumor SI motion standard deviation >5 mm). Furthermore, 92,956 frames of images were analyzed for the 6 large-amplitude motion patients. For this set, correlation coefficients were 0.93 ± 0.07 between any 2 features among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.94 ± 0.06 between SI and any feature among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; and 0.90 ± 0.09 between SI and Belly. Both belly and diaphragmatic motions as assessed by cine MRI are highly correlated with large amplitude lung tumor motion in the longitudinal axis.

Clinical study of magnetic resonance imaging-based texture analysis and fasciculation of the lateral pterygoid muscle in young patients with temporomandibular disorder

We aimed to evaluate the effectiveness of clinical examination combined with texture analysis of magnetic resonance imaging (MRI) and fasciculation patterns of the lateral pterygoid muscle (LPM) in distinguishing among the different anatomic causes of temporomandibular disorder. We divided the patients into four groups: healthy control (HC), disk without displacement (DWoD), disk displacement with reduction (DDWR), and disk displacement without reduction (DDWoR). Demographic information and clinical symptoms of patients in each group were recorded. LPM textures were compared among groups. LPM fasciculation was examined. P<0.05 indicated significant difference. Several clinical symptoms and signs, but not age or sex, differed significantly among groups. Oblique sagittal planar MRI revealed significant differences in the parameters of Angular Second Moment, Contrast, Correlation, Inverse Difference Moment, and Entropy between the healthy controls and the 3 patient groups. MRI of the patients, both without and with disk displacement, demonstrated relative uniformity in gray distribution and correlation of gray values, with greater complexity but an unclear texture and no obvious regularity. The proportion of type B LPM fascicles was significantly higher in the DDWR and DDWoR groups CONCLUSION: Temporomandibular disorder, without and with disk displacement, is associated with clinical symptoms and texture analysis values that differ from healthy muscle. The types of LPM fascicles are related to the position of the articular disk.

Hypoglycaemic Encephalopathy following Coronavirus Disease in a Six-month-old Infant: A Rare Case Report

Hypoglycaemia refers to a state when the blood sugar level drops below the normal range of 70-110 mg/dL. Blood sugar level, or glucose in the blood, is responsible for various vital functions. A decrease in blood glucose levels causes a wide range of clinical presentations, from tremors to coma and even death. Long-term hypoglycaemia can lead to extensive neuronal damage due to apoptosis and energy failure. Additionally, authors discuss a rare case of a six-month-old male neonate who presented with fever, diarrhoea, and two episodes of convulsions over the last two days. The movements started with an ictal cry and were followed by micturition and defecation. Nasal and throat swabs were positive for SARS-CoV-2 viral antigen. A plane Magnetic Resonance Imaging (MRI) of the brain was performed, which revealed evidence of altered signal intensity in the cortical and subcortical areas of the right frontal-temporal-parietal-occipital region, suggesting hypoglycaemic encephalopathy. The patient was given a breastfeeding trial and managed with 25% dextrose initially at a rate of 0.2 g/kg for 48 hours, as the patient was symptomatic, followed by an infusion of dextrose normal saline. After ruling out all possibilities of hypoglycaemic encephalopathy, the diagnosis of hypoglycaemic encephalopathy secondary to Coronavirus Disease (COVID-19) was made.

The Pelican Sign: Case Series Demonstrating A Unique Description of an Anteriorly Flipped Bucket-Handle Meniscal Tear of the Knee.

Introduction Bucket-handle tears (BHTs) of the menisci are not uncommon and can occur in isolation or in conjunction with other injuries. The torn fragment can be displaced within the intercondylar notch or flipped anteriorly. In case of anterior flipped fragment, appearances of such tears on magnetic resonance imaging (MRI) scan have been described as various signs in literature (for example double posterior cruciate ligament sign, double delta sign) but mostly in the sagittal or coronal planes. Purpose The aim of this study was to describe a unique ancillary sign that helps to identify this injury on the axial MRI plane where the anterior flipped BHT figuratively resembles a "pelican bird." Materials and Methods A retrospective review of MRI sequences of 10 consecutive patients over a 3-month period referred following a traumatic knee injury with anterior flipped meniscal tears was performed. Demographic details, clinical indication, and other associated features on the MRI were correlated following the observation of characteristic MRI appearance of a BHT. Results All 10 patients (M:F = 7:3) with a mean age of 24.7 (17-38 years) presented following a twisting injury. 6 out of 10 patients had associated soft-tissue injuries in the knee visualized on the MRI. All patients demonstrated the distinctive "pelican bird" sign on the axial sequences of anterior flipped BHT of either menisci. This was not present with BHTs with displaced fragment within the intercondylar notch. Conclusion We conclude that the "pelican sign" on an axial sequence when present correlates well with a BHT and its anterior displaced/flipped meniscal fragment. This ancillary sign can complement other previously described signs on different MRI sequences used to confirm a displaced BHT.

Sagittal Plane Geometry of Cervical, Thoracic, and Lumbar Endplates.

Many studies have emphasized the importance of interface contact between implants and the vertebral endplate (VE). The goal of this study was to analyze the shape and other specific parameters of the VE to provide reference data for better implant interface contact in intervertebral disc space procedures. Cervical, thoracic, and lumbar spine midsagittal plane magnetic resonance images of 100 adults (58 women) were analyzed. The morphology of the VEs was classified as concave, convex, flat, or irregular. Midsagittal endplate length (ML), endplate concavity depth (ECD), and endplate concavity axis (ECA) location were measured in the midsagittal plane. The parameters were compared between the cervical, thoracic, and lumbar spines and between the sexes. The VE morphology, ML, ECD, and ECA showed variations along the spine, mainly in the cervical and lower lumbar spines. The sagittal geometry of the VE was not flat or uniform along the cervical, thoracic, and lumbar spines. Different morphological types were observed along different spinal segments and according to sex. In the cervical spine, the majority of cranial VEs were flat, while caudal VEs were mostly concave. Sagittal VE geometry should be taken into consideration during the use of intervertebral cages or disc arthroplasty.

3D Reconstruction of a Unitary Posterior Eye by Converging Optically Corrected Optical Coherence and Magnetic Resonance Tomography Images via 3D CAD.

PurposeIn acquiring images of the posterior eye, magnetic resonance imaging (MRI) provides low spatial resolution of the overall shape of the eye while optical coherence tomography (OCT) offers high spatial resolution of the limited range. Through the merger of the two devices, we attempted to acquire detailed anatomy of the posterior eye.MethodsOptical and display distortions in OCT images were corrected using the Listing reduced eye model. The 3.0T orbital MRI images were placed on the three-dimensional coordinate system of the computer-aided design (CAD) program. Employing anterior scleral canal opening, visual axis, and scleral curvature as references, original and corrected OCT images were ported into the CAD application. The radii of curvature of the choroid–scleral interfaces (Rc values) of all original and corrected OCT images were compared to the MRI images.ResultsSixty-five eyes of 33 participants (45.58 ± 19.82 years) with a mean Rc of 12.94 ± 1.24 mm on axial MRI and 13.66 ± 2.81 mm on sagittal MRI were included. The uncorrected horizontal OCT (30.51 ± 9.34 mm) and the uncorrected vertical OCT (34.35 ± 18.09 mm) lengths differed significantly from the MRI Rc values (both P < 0.001). However, the mean Rc values of the corrected horizontal (12.50 ± 1.21 mm) and vertical (13.05 ± 1.98 mm) images did not differ significantly from the Rc values of the corresponding MRI planes (P = 0.065 and P = 0.198, respectively).ConclusionsFeatures identifiable only on OCT and features only on MRI were successfully integrated into a unitary posterior eye.Translational RelevanceOur CAD-based converging method may establish the collective anatomy of the posterior eye and the neural canal, beyond the range of the OCT.

Comparative Analysis of Backbone Networks for Deep Knee MRI Classification Models

This paper focuses on different types of backbone networks for machine learning architectures which perform classification of knee Magnetic Resonance Imaging (MRI) images. This paper aims to compare different types of feature extraction networks for the same classification task, in terms of accuracy and performance. Multiple variations of machine learning models were trained based on the MRNet architecture, choosing AlexNet, ResNet, VGG-11, VGG-16, and Efficientnet as the backbone. The models were evaluated on the MRNet validation dataset, computing Area Under the Receiver Operating Characteristics Curve (ROC-AUC), accuracy, f1 score, and Cohen’s Kappa as evaluation metrics. The MRNet-VGG16 model variant shows the best results for Anterior Cruciate Ligament (ACL) tear detection. For general abnormality detection, MRNet-VGG16 is dominated by MRNet-Resnet in confidence between 0.5 and 0.75 and by MRNet-VGG11 for confidence more than 0.8. Due to the non-uniform nature of backbone network performance on different MRI planes, it is advisable to use an LR ensemble of: VGG16 on a coronal plane for all classification tasks; on an axial plane for abnormality and ACL tear detection; Alexnet on a sagittal plane for abnormality detection, and an axial plane for meniscal tear detection; and VGG11 on a sagittal plane for ACL tear detection. The results also indicate that the Cohen’s Kappa metric is valuable in model evaluation for the MRNet dataset, as it provides deeper insights on classification decisions.

Abstract 479: The role of diffusion in molecular networks: Diffusion coefficients in describing the development of cancer

Abstract To study and forecast the developments of cancers, the molecular networks, compositional fluctuations, diffusion in networks and altogether the biological processes resulting at cellular and intracellular levels, are highly important. Focusing on diffusion coefficients as the translational biomarkers to quantify the nucleation and growth of tumors and cancers has potential advantages. Because, diffusion coefficients act as guiding tools in preventing or treating the cancers and associated adversities. Collectively the biological, pharmacological and toxicological indicators during and prior to the course of cancer are taken as measures for the data over specific distances of the molecules to determine diffusion coefficients. Because, multiple mechanisms are simultaneously responsible in altering the compositions. In this work, the mass transportation in both healthy individuals and cancer patients are taken into account to compare and contrast the initiation and spread of cancers in the light of immunology and immunotherapy. Measurements through incoherent motion diffusion-weighted imaging (IVIM-DWI) and echo planar magnetic resonance (MR) imaging are applied in determining the diffusion parameters. Diffusion coefficients were within the ranges of 0.1 to 5 X 10-3 mm2/sec. Perfusion played important role in quantifications. Magnitudes of diffusion coefficients are used to forecast biological prevalence and to develop prevention and treatment therapeutics. Citation Format: Narayana Garimella. The role of diffusion in molecular networks: Diffusion coefficients in describing the development of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 479.

Comparison between the coronal diameters of the cervical spinal canal and spinal cord measured using computed tomography and magnetic resonance imaging in Korean patients.

BackgroundIf the proportion of the spinal cord in the epidural space can be determined under C-arm fluoroscopy during cervical epidural block, a safe entry point for the epidural needle can be established. The aim of this study was the measurement of the cord to canal transverse diameter ratio of each cervical spines. MethodsWe retrospectively evaluated the imaging data of 100 patients who underwent both cervical computed tomography (CT) and cervical magnetic resonance imaging (MRI) at our hospital. We measured the diameters of the spinal canal and spinal cord from the 3rd cervical vertebra to the 1st thoracic vertebra (T1) at each level by using the patients’ cervical CT and MRI images. The spinal cord and spinal canal diameters were measured in the transverse plane of the cervical MRI and CT images, respectively.ResultsThe spinal cord to spinal canal diameter ratio was the highest at the 4th and 5th cervical vertebrae (0.64 ± 0.07) and the lowest at T1 (0.55 ± 0.06, 99% CI [0.535, 0.565].ConclusionsOur findings suggest that the cord to canal transverse diameter ratio could be used as a reference to reduce direct spinal cord injuries during cervical epidural block under C-arm fluoroscopy. In the C-arm fluoroscopic image, if an imaginary line connecting the left and right innermost lines of the pedicles of T1 is drawn and if the needle is inserted into the outer one-fifth of the left and right sides, the risk of puncturing the spinal cord would be relatively reduced.

Correlation of histopathology and multi-modal magnetic resonance imaging in childhood osteosarcoma: Predicting tumor response to chemotherapy.

BackgroundOsteosarcoma, which is the most common malignant pediatric bone cancer, remains dependent on an imprecise systemic treatment largely unchanged in 30 years. In this study, we correlated histopathology with magnetic resonance imaging (MRI), used the correlation to extract MRI-specific features representative of tumor necrosis, and subsequently developed a novel classification model for predicting tumor response to neoadjuvant chemotherapy in pediatric patients with osteosarcoma using multi-modal MRI. The model could ultimately serve as a testable biomarker for a high-risk malignancy without successful precision treatments.MethodsPatients with newly diagnosed high-grade appendicular osteosarcoma were enrolled in a single-center observational study, wherein patients underwent pre-surgical evaluation using both conventional MRI (post-contrast T1-weighted with fat saturation, pre-contrast T1-weighted, and short inversion-time inversion recovery (STIR)) and advanced MRI (diffusion weighted (DW) and dynamic contrast enhanced (DCE)). A classification model was established based on a direct correlation between histopathology and MRI, which was achieved through histologic-MR image co-registration and subsequent extraction of MR image features for identifying histologic tumor necrosis. By operating on the MR image features, tumor necrosis was estimated from different combinations of MR images using a multi-feature fuzzy clustering technique together with a weighted majority ruling. Tumor necrosis calculated from MR images, for either an MRI plane of interest or whole tumor volume, was compared to pathologist-estimated necrosis and necrosis quantified from digitized histologic section images using a previously described deep learning classification method.Results15 patients were enrolled, of whom two withdrew, one became ineligible, and two were subjected to inadequate pre-surgical imaging. MRI sequences of n = 10 patients were subsequently used for classification model development. Different MR image features, depending on the modality of MRI, were shown to be significant in distinguishing necrosis from viable tumor. The scales at which MR image features optimally signified tumor necrosis were different as well depending on the MR image type. Conventional MRI was shown capable of differentiating necrosis from viable tumor with an accuracy averaging above 90%. Conventional MRI was equally effective as DWI in distinguishing necrotic from viable tumor regions. The accuracy of tumor necrosis prediction by conventional MRI improved to above 95% when DCE-MRI was added into consideration. Volume-based tumor necrosis estimations tended to be lower than those evaluated on an MRI plane of interest.ConclusionsThe study has shown a proof-of-principle model for interpreting chemotherapeutic response using multi-modal MRI for patients with high-grade osteosarcoma. The model will continue to be evaluated as MR image features indicative of tumor response are now computable for the disease prior to surgery.

Prevalence and clinical potential of extraspinal incidental findings in lumbosacral spine MRI of patients with suspected disc diseases

BACKGROUND Incidental findings could be observed in organs close to the spine while reporting lumbosacral spine magnetic resonance imaging (MRI). This study aimed to report the prevalence and clinical potential of extraspinal incidental findings in lumbosacral MRI of patients with suspected disc diseases.&#x0D; METHODS This single-centered cross-sectional study was carried out on 420 consecutive adult patients who underwent lumbar spine MRI for suspected disc disease from January to July 2019. The MRI was checked for the presence of extraspinal incidental findings, and each finding was categorized according to the body organ and its clinical significance. Each MRI plane that best displayed the findings was recorded, and the association between the findings and patient's age and sex was determined.&#x0D; RESULTS Of 420 samples, 135 cases showed extraspinal findings (32.1%), and 7.6% of the patients displayed suspicious lesions. The urinary tract was the most common system (18.6%) to display both clinically significant (5.0%) and benign findings (13.6%), and the axial MRI section was the plane which showed most of the incidental findings. Incidental findings in any body system were rarely found in the younger patients. Females had significantly higher benign findings than males (p = 0.002).&#x0D; CONCLUSIONS The prevalence of extraspinal findings in lumbosacral spine MRI is high, and some are significant. Most findings are related to the urinary tract and best displayed in the axial plane.

Variances of the intraarticular landmarks for anterior cruciate ligament tibial footprint: Tibial eminencies have less variability than lateral meniscus on sagittal magnetic resonance scans

Objective: The purpose of this study was to analyze the sagittal plane variations of intraarticular landmarks for single bundle anterior cruciate ligament (ACL) reconstruction including lateral meniscus, medial and lateral tibial eminencies. Methods: T2 weighted sagittal magnetic resonance (MR) scans of 80 skeletally mature patients aged between 18 to 60 years and without any sign of ligament and meniscal injuries were viewed. Midpoint of ACL, most posterior aspect of anterior horn of lateral meniscus (LMAH), tip of medial eminence (ME) and lateral eminence (LE) were identified on widest antero-posterior (A-P) distance of tibial plateau according to of Staubli-Rausching method and variances were compared. Results: Mean location of center of tibial footprint of ACL at sagittal plane was found as 38.0±4.2% (range, 29-51%) on A-P distance of tibial plateau. Location of posterior border of LMAH, ME and LE were 38.0±12.4% (range, 21-62%), 52.3±4.2% (range, 41- 60%) and 59.5±4.4% (range, 51- 69%), respectively. Difference between the variances of ACL midpoint and LMAH was large enough to be statistically significant (p=&lt;.001) with a large effect size (f=0.59), however differences between the variances of ACL midpoint and bony landmarks were not significant (ME, p=.65; LE, p=.33). Intra and interobserver agreement for measurement of all parameters were detected as moderate to good. Conclusion: There was no constant relationship between ACL midpoint and posterior border of LMAH on sagittal plane MR images. Difference of variances between ACL midpoint and ME and LE were significantly lower than of variances of LMAH.

Subacromial impingement syndrome: association of multiple magnetic resonance imaging parameters with shoulder function and pain

IntroductionShoulder pain is one of the most common complaints in orthopaedics. This study focusses on the relationship between shoulder function in subacromial impingement syndrome and imaging criteria in magnetic resonance imaging (MRI).Materials and methodsThis prospective clinical trial included 69 patients treated for subacromial impingement syndrome. Shoulder function (Constant Score, range of abduction, abduction force) and pain were correlated with the following MRI parameters: tendinosis of the rotator cuff, “halo-sign” around the biceps tendon, subacromial distance, critical shoulder angle, size of subacromial osteophytic spurs and maximum width of subacromial and subdeltoid bursa. Statistical analyses included Pearson’s and Spearman’s coefficients of correlation, multiple regression analysis and Student’s t-test.ResultsThe Constant Score was correlated positively with the critical shoulder angle (r = 0.313; p = 0.009) and inversely with a “halo-sign” around the biceps tendon (rho = −0.384; p = 0.001). There was no significant correlation between spur size and shoulder function, but the size of the subacromial and subdeltoid bursae was positively correlated with the subacromial spur’s size (subacromial bursa: coronal plane: r = 0.327; p = 0.006; sagittal view: r = 0.305; p = 0.011; subdeltoid bursa coronal view: r = 0.333 p = 0.005). The width of the subdeltoid bursa in coronal plane was positively correlated with shoulder pain (r = 0.248; p = 0.004) and negatively with the range of abduction (r = −0.270; p = 0.025), as well as the mean (r = −0.332; p = 0.005) and maximum (r = −0.334; p = 0.005) abduction force.ConclusionsShoulder function and pain in subacromial impingement are best predicted by the width of the subdeltoid bursa measured in the coronal MRI plane as an indicator of bursitis as well as the presence of a “halo-sign” around the biceps tendon indicating glenohumeral joint effusion. Presence of a subacromial spur could lead to subacromial and subdeltoid bursitis, which impairs shoulder function. Shoulder function seems not to be compromised by the presence of a subacromial spur in absence of bursitis.This study was registered at the German Clinical Trials Register on 08 February 2013 (ID: DRKS00011548).

The Anterior Cruciate Ligament Can Become Hypertrophied in Response to Mechanical Loading: A Magnetic Resonance Imaging Study in Elite Athletes

Background: Evidence, mainly from animal models, suggests that exercise during periods of pubertal growth can produce a hypertrophied anterior cruciate ligament (ACL) and improve its mechanical properties. In humans, the only evidence of ACL hypertrophy comes from a small cross-sectional study of elite weight lifters and control participants; that study had methodological weaknesses and, thus, more evidence is needed. Purpose: To investigate bilateral differences in the ACL cross-sectional area (CSA) for evidence of unilateral hypertrophy in athletes who have habitually loaded 1 leg more than the other. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We recruited 52 figure skaters and springboard divers (46 female and 6 male; mean age, 20.2 ± 2.7 years) because the former always land/jump on the same leg while the latter always drive the same leg into the board during their hurdle approach. Sport training for all participants began before puberty and continued throughout as well as after. Using oblique axial– and oblique sagittal–plane magnetic resonance imaging, we measured the ACL CSA and the anteroposterior diameter of the patellar tendon, respectively. In addition, isometric and isokinetic knee extensor and flexor peak torques were acquired using a dynamometer. Bilateral differences in the ACL CSA, patellar tendon diameter, and knee muscle strength were evaluated via 2-sided paired-samples t tests. Correlations between the bilateral difference in the ACL CSA and age of training onset as well as between the bilateral difference in the ACL CSA and years of training were also examined. Results: A significantly larger ACL CSA (mean difference, 4.9% ± 14.0%; P = .041), as well as patellar tendon diameter (mean difference, 4.7% ± 9.4%; P = .002), was found in the landing/drive leg than in the contralateral leg. The bilateral difference in the ACL CSA, however, was not associated with the age of training onset or years of training. Last, the isometric knee flexor peak torque was significantly greater in the landing/drive leg than the contralateral leg (mean difference, 14.5% ± 33.8%; P = .019). Conclusion: Athletes who habitually loaded 1 leg more than the other before, during, and after puberty exhibited significant unilateral ACL hypertrophy. This study suggests that the ACL may be able to be “trained” in athletes. If done correctly, it could help lower the risk for ACL injuries.