Magnetic Resonance Imaging Machine Research Articles

Improved Magnetic Resonance Image Reconstruction using Compressed Sensing and Adaptive Multi Extreme Particle Swarm Optimization Algorithm

One powerful technique that can offer a thorough examination of the body's internal structure is magnetic resonance imaging (MRI). MRI's lengthy acquisition times, however, may restrict its clinical usefulness, particularly in situations where time is of the essence. Compressed sensing (CS) has emerged as a potentially useful method for cutting down on MRI acquisition times; nevertheless, the effectiveness of CS-MRI is dependent on the selection of the sparsity-promoting algorithm and sampling scheme. This research paper presents a novel method based on adaptive multi-extreme particle swarm optimization (AMEPSO) and dual tree complex wavelet transform (DTCWT) for fast image acquisition in magnetic resonance. The method uses AMEPSO in order to maximize the sampling pattern and minimize reconstruction error, while also exploiting the sparsity of MR images in the DTCWT domain to improve directional selectivity and shift invariance. MATLAB software was used for simulation of the proposed method. In comparison with the particle swarm optimized-DTCWT (PSODTCWT) and DTCWT algorithms, respectively, the results demonstrated an improvement in the peak signal-to-noise ratio of 8.92% and 15.92% and a higher structural similarity index measure of 3.69% and 7.5%. Based on these improvements, the proposed method could potentially make high-quality, real-time MRI imaging possible, which might improve detection and treatment of medical conditions and increase the throughput of MRI machines.

Computational-Design Enabled Wearable and Tunable Metamaterials via Freeform Auxetics for Magnetic Resonance Imaging.

Metamaterials hold significant promise for enhancing the imaging capabilities of magnetic resonance imaging (MRI) machines as an additive technology, due to their unique ability to enhance local magnetic fields. However, despite their potential, the metamaterials reported in the context of MRI applications have often been impractical. This impracticality arises from their predominantly flat configurations and their susceptibility to shifts in resonance frequencies, preventing them from realizing their optimal performance. Here, a computational method for designing wearable and tunable metamaterials via freeform auxetics is introduced. The proposed computational-design tools yield an approach to solving the complex circle packing problems in an interactive and efficient manner, thus facilitating the development of deployable metamaterials configured in freeform shapes. With such tools, the developed metamaterials may readily conform to a patient's knee, ankle, head, or any part of the body in need of imaging, and while ensuring an optimal resonance frequency, thereby paving the way for the widespread adoption of metamaterials in clinical MRI applications.

Sagittal balance parameters measurement on cervical spine MR images based on superpixel segmentation.

Introduction: Magnetic Resonance Imaging (MRI) is essential in diagnosing cervical spondylosis, providing detailed visualization of osseous and soft tissue structures in the cervical spine. However, manual measurements hinder the assessment of cervical spine sagittal balance, leading to time-consuming and error-prone processes. This study presents the Pyramid DBSCAN Simple Linear Iterative Cluster (PDB-SLIC), an automated segmentation algorithm for vertebral bodies in T2-weighted MR images, aiming to streamline sagittal balance assessment for spinal surgeons. Method: PDB-SLIC combines the SLIC superpixel segmentation algorithm with DBSCAN clustering and underwent rigorous testing using an extensive dataset of T2-weighted mid-sagittal MR images from 4,258 patients across ten hospitals in China. The efficacy of PDB-SLIC was compared against other algorithms and networks in terms of superpixel segmentation quality and vertebral body segmentation accuracy. Validation included a comparative analysis of manual and automated measurements of cervical sagittal parameters and scrutiny of PDB-SLIC's measurement stability across diverse hospital settings and MR scanning machines. Result: PDB-SLIC outperforms other algorithms in vertebral body segmentation quality, with high accuracy, recall, and Jaccard index. Minimal error deviation was observed compared to manual measurements, with correlation coefficients exceeding 95%. PDB-SLIC demonstrated commendable performance in processing cervical spine T2-weighted MR images from various hospital settings, MRI machines, and patient demographics. Discussion: The PDB-SLIC algorithm emerges as an accurate, objective, and efficient tool for evaluating cervical spine sagittal balance, providing valuable assistance to spinal surgeons in preoperative assessment, surgical strategy formulation, and prognostic inference. Additionally, it facilitates comprehensive measurement of sagittal balance parameters across diverse patient cohorts, contributing to the establishment of normative standards for cervical spine MR imaging.

Utility of Chemical Shift Imaging and Diffusion-weighted Images/Apparent Diffusion Coefficient Maps as a Tool for Evaluation of Solid Renal Tumors.

To study the utility of chemical shift imaging (CSI) and diffusion-weighted images (DWI)/apparent diffusion coefficient (ADC) maps for the evaluation of solid renal tumors. Magnetic resonance imaging (MRI) has an equivalent application as computerized tomography (CT) in the characterization of renal masses. It offers a radiation-free imaging technique and has a better soft tissue contrast than CT. Also, MRI is favored in patients with chronic kidney disease. MRI is useful when findings on CT are equivocal. The role of DWI in characterizing solid renal lesions as malignant is encouraging, and DWI can be particularly useful when gadolinium is contraindicated. CSI is useful in differentiating angiomyolipoma (AML) from clear cell (cc) renal cell carcinoma (RCC). We did a cross-sectional study on 24 patients with solid renal masses. MRI of the upper abdomen (from the dome of the diaphragm to the iliac crest) will be done on an MRI machine in our department (1.5T, ACHIEVA, Phillips medical system) using the torso coil. There was no significant association seen in terms of ADC values and histological subtypes (χ2 = 11.222, p = 0.082). In our study, 50% (one out of two) of AML showed a signal drop, whereas 40% of cases (6 out of 15) of ccRCC and 66% (two out of three) of papillary RCC showed a signal drop. In this article, we concluded CSI, although a useful tool to look for microscopic fat, can't be used as a reliable marker to rule in cc-carcinoma as both AML and papillary cell carcinoma have microscopic fat. Further, no histological classification can be done on the basis of DWI/ADC images.

Overcoming Operational Challenges: A Case Study of MRI Functionality in Resource-Scarce Regions

Magnetic resonance imaging(MRI) is a veritable radiological diagnostic tool for the in-depth diagnosis of various ailment involving virtually all organ systems of the human body. The machinery for this radiological investigation tool is quite huge and needs installation in a spacious, well ventilated and air-conditioned room. It also must have verified working alternative power source as the essential lithium gas needed for its proper working must be kept cool at all times, and the environment where the MRI equipment is installed must always be kept at an ambient room temperature. This requirement means that a regular power supply must be assured as the lack of it may impact negatively on the functional ability of the equipment, which was procured at a great cost, its installation and maintenance also at a great deal of scarce fund. So, all care must be put in place not to endanger the perfect workings of the MRI equipment. Angry hospital workers deliberately shut off the electrical and water supply to the MRI unit in protest, aiming to force management to address their grievances. However, this action had severe consequences for the MRI machine, as its cooling system for the essential helium gas was disrupted, leading to gas depletion from the cannisters. This incident underscores the critical need for uninterrupted power and cooling systems in MRI installations to ensure their proper functioning and avoid costly damage.

Morphometric Analysis of the Eye by Magnetic Resonance Imaging in MGST2-Gene-Deficient Mice.

Strabismus, a neuro-ophthalmological condition characterized by misalignment of the eyes, is a common ophthalmic disorder affecting both children and adults. In our previous study, we identified the microsomal glutathione S-transferase 2 (MGST2) gene as one of the potential candidates for comitant strabismus susceptibility in a Japanese population. The MGST2 gene belongs to the membrane-associated protein involved in the generation of pro-inflammatory mediators, and it is also found in the protection against oxidative stress by decreasing the reactivity of oxidized lipids. To look for the roles of the MGST2 gene in the development, eye alignment, and overall morphology of the eye as the possible background of strabismus, MGST2 gene knockout (KO) mice were generated by CRISPR/Cas9-mediated gene editing with guide RNAs targeting the MGST2 exon 2. The ocular morphology of the KO mice was analyzed through high-resolution images obtained by a magnetic resonance imaging (MRI) machine for small animals. The morphometric analyses showed that the height, width, and volume of the eyeballs in MGST2 KO homozygous mice were significantly greater than those of wild-type mice, indicating that the eyes of MGST2 KO homozygous mice were significantly enlarged. There were no significant differences in the axis length and axis angle. These morphological changes may potentially contribute to the development of a subgroup of strabismus.

Role of MRI in detection of lumber spine pathologies using 1.5 tesla (MRI)

Background: This study investigates the diagnostic accuracy of MRI in detecting various lumbar spine pathologies in patients with lower back pain. Lower back pain (LBP) is a prevalent issue affecting 80%–85% of the population during their lifetime, contributing significantly to global disability. LBP is nonspecific in 95% of cases but can stem from underlying pathologies such as disc herniation, spinal stenosis, infection, inflammation, tumours, or fractures. Objective: To emphasize the importance of magnetic resonance imaging (MRI) in patients suspected of lumbar spinal examinations. Methods and material: The research focused on adult patients with radicular syndrome, spinal stenosis, spinal tumours, spinal fractures, spinal infection/inflammation, disc herniation, spondylolisthesis, spondylolysis, ankylosing spondylitis, disc displacement, osteoporotic fractures, and other degenerative disc diseases. Utilizing a 1.5 Tesla MRI machine, the descriptive, cross-sectional observational study spanned one year and included 150 patients. Results: revealed that diffuse disc bulge (87.33%) and disc protrusion (87.33%) were the most common pathologies, followed by partial desiccation (34.67%), neural foramina stenosis (16.00%), spondylosis (1.33%), osteoporosis (12.00%), spinal haemorrhage (2.00%), osteophyte spurs (29.33%), and sclerotic changes (3.33%). Discussion and Conclusion: The study's discussion highlighted notable findings, including a higher prevalence of lumbar spine abnormalities in females (51.33%) and a substantial association with a history of lower back pain (40.00%). The conclusion underscores the significance of MRI in diagnosing lumbar spine pathologies, with specific attention to the prevalence of disc bulge and protrusion in the studied population.

Cortical atrophy in early-stage patients with anti-NMDA receptor encephalitis: a machine-learning MRI study with various feature extraction.

Conventional brain magnetic resonance imaging (MRI) of anti-N-methyl-D-aspartate-receptor encephalitis (NMDARE) is non-specific, thus showing little differential diagnostic value, especially for MRI-negative patients. To characterize patterns of structural alterations and facilitate the diagnosis of MRI-negative NMDARE patients, we build two support vector machine models (NMDARE versus healthy controls [HC] model and NMDARE versus viral encephalitis [VE] model) based on radiomics features extracted from brain MRI. A total of 109 MRI-negative NMDARE patients in the acute phase, 108 HCs and 84 acute MRI-negative VE cases were included for training. Another 29 NMDARE patients, 28 HCs and 26 VE cases were included for validation. Eighty features discriminated NMDARE patients from HCs, with area under the receiver operating characteristic curve (AUC) of 0.963 in validation set. NMDARE patients presented with significantly lower thickness, area, and volume and higher mean curvature than HCs. Potential atrophy predominately presented in the frontal lobe (cumulative weight = 4.3725, contribution rate of 29.86%), and temporal lobe (cumulative weight = 2.573, contribution rate of 17.57%). The NMDARE versus VE model achieved certain diagnostic power, with AUC of 0.879 in validation set. Our research shows potential atrophy across the entire cerebral cortex in acute NMDARE patients, and MRI machine learning model has a potential to facilitate the diagnosis MRI-negative NMDARE.

Kenya Psychosis-Risk Outcomes Study (KePROS): Development of an Accelerated Medicine Partnership Schizophrenia-Aligned Project in Africa

Abstract Background and Hypothesis The Accelerating Medicines Partnership Schizophrenia (AMP SCZ) funds a longitudinal study of 43 research sites across 5 continents to develop tools to stratify developmental trajectories of youth at clinical high risk for psychosis (CHR) and identify homogenous targets for future clinical trials. However, there are no sites in Africa, leaving a critical gap in our knowledge of clinical and biological outcomes among CHR individuals. Study Design We describe the development of the Kenya Psychosis-Risk Outcomes Study (KePROS), a 5-year NIH-funded project in Kenya designed to harmonize with AMP SCZ. The study will recruit over 100 CHR and 50 healthy participants and conduct multiple clinical and biomarker assessments over 2 years. Capacity building is a key component of the study, including the construction of an electroencephalography (EEG) laboratory and the upgrading of a local 3 T magnetic resonance imaging (MRI) machine. We detail community recruitment, study methodologies and protocols, and unique challenges with this pioneering research in Africa. Study Results This paper is descriptive only. Planned future analyses will investigate possible predictors of clinical outcomes and will be compared to results from other global populations. Conclusions KePROS will provide the research community with a rich longitudinal clinical and biomarker dataset from an African country in the developing Global South, which can be used alongside AMP SCZ data to delineate CHR outcome groups for future treatment development. Training in mental health assessment and investment in cutting-edge biomarker assessment and other technologies is needed to facilitate the inclusion of African countries in large-scale research consortia.

The Incidence of the Associated Meniscal Ligament (ML) With the Anterior Cruciate Ligament (ACL) Tears

Objective: To assess the incidence of the associated meniscal ligament (ML) with the anterior cruciate ligament (ACL) tears in hospital A in Medina-KSA. And to see the effect of sports activities in comparison between males and females. 
 Materials and Methods: In a retrospective study, ninety-nine patients' knee magnetic resonance imaging (MRI) records were selected conveniently from the (A) hospital's picture archiving and communication system (PACS). Patients with suspected anterior cruciate and meniscal ligament' tears were included. Patients with posterior cruciate ligament (PCL) tear, medial collateral ligament (MCL) or lateral collateral ligament (LCL) injury, and previously operated index knees were excluded. All patients were scanned by a 1.5T MRI machine using standard MRI knee scanning protocol. The categorical and continuous variables were presented as percentages, frequencies, and descriptive statistics. The cross-tabulations and chi-square test were applied to obtain the statistical associations between the study variables. A statistical association was considered significant if the P-value was < 0.05. 
 Results: 72 males and 27 females were included, with a mean age of 33 ± 2.43. 42.4% of the knee tears were ML tears, followed by associated (ACL with ML) tears, noted in 31.3%, and 26.3% were ACL tears. The tears were more frequent in the age group (31-40), reported in 35.3% (out of 99). There was no statistical association between the tears and the participants' age, gender, or sports activities; P value = 0.3, 0.5, and 0.9, respectively. 
 Conclusion: The study concluded that the isolated ML tears were more frequent than the associated (ACL with ML) tears—moreover, there was no significant statistical association between the participants' age, gender, or sports activities.

Evaluating the axonal injury and predicting the motor function recovery in supratentorial acute stroke patients

PurposeThis study aims to evaluate axonal injury in supratentorial acute stroke patients and predict motor function recovery. MethodsA cross-sectional descriptive study was performed on 28 patients with supratentorial acute stroke. All patients underwent brain magnetic resonance imaging (MRI) at Bach Mai Hospital from September 2021 to August 2022. Diffuse tensor imaging (DTI) was conducted using a 3-Tesla MRI machine to evaluate the association between the corticospinal tract and infarct area. Therefore, axonal injury and motor function recovery levels could be predicted. ResultsAlmost patients had no change in the signal of the axons, which did not pass through the infarct lesion (28.6%), and the signals strongly decreased in patients whose axons completely stayed inside the infarct lesion (32.1%). The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) indices of the axons on the infarcted side were lower than those of axons on the contralateral side. The patient group, in which the axons did not pass through the infarct lesion or had no change in axonal signals, had a higher rate of better motor function recovery after 3 months than the other groups (39.3% and 25 %, respectively), whereas the axon group, in which the axons stayed completely inside the infarct lesion or had a remarkably decreased signal, had a very poor rate of recovery (32.1% and 39.3 %, respectively). The FA index of the axons on the infarct side in the poor recovery group was lower than that in the good recovery group. The ADC index did not differ between the groups. ConclusionMRI finding with axonal signal, location, and infarct side could significantly predict motor recovery after 3 months in acute stroke patients.

Sophisticated Study of Time, Frequency and Statistical Analysis for Gradient-Switching-Induced Potentials during MRI.

Magnetic resonance imaging (MRI) is a standard procedure in medical imaging, on a par with echography and tomodensitometry. In contrast to radiological procedures, no harmful radiation is produced. The constant development of magnetic resonance imaging (MRI) techniques has enabled the production of higher resolution images. The switching of magnetic field gradients for MRI imaging generates induced voltages that strongly interfere with the electrophysiological signals (EPs) collected simultaneously. When the bandwidth of the collection amplifiers is higher than 150 Hz, these induced voltages are difficult to eliminate. Understanding the behavior of these artefacts contributes to the development of new digital processing tools for better quality EPs. In this paper, we present a study of induced voltages collected in vitro using a device (350 Hz bandwidth). The experiments were conducted on a 1.5T MRI machine with two MRI sequences (fast spin echo (FSE) and cine gradient echo (CINE)) and three slice orientations. The recorded induced voltages were then segmented into extract patterns called "artefact puffs". Two analysis series, "global" and "local", were then performed. The study found that the temporal and frequency characteristics were specific to the sequences and orientations of the slice and that, despite the pseudo-periodic character of the artefacts, the variabilities within the same recording were significant. These evolutions were confirmed by two stationarity tests: the Kwiatkowski-Phillips-Schmidt-Shin (KPSS) and the time-frequency approach. The induced potentials, all stationary at the global scale, are no longer stationary at the local scale, which is an important issue in the design of optimal filters adapted to reduce MRI artifacts contaminating a large bandwidth, which varies between 0 and 500 Hz.

The Effect of Orientation on Increasing Knowledge and Reducing Anxiety During MRI Examination in a Radiology Installation

Radiology services encompass the use of ionizing and non-ionizing radiation sources for diagnostic imaging and therapy. Magnetic Resonance Imaging (MRI) is a crucial clinical radiology service, primarily conducted in hospital-based healthcare facilities. The aim of this research is to assess the influence of patient orientation on MRI-related knowledge and anxiety. This study employs a quasi-experimental design with pretest and posttest measurements, taking into account variables such as age, gender, education, diagnosis, and experience. The results of the research indicate that patient orientation effectively reduces anxiety levels and has a positive impact on the patient's experience during MRI examinations. The conclusions that can be drawn from this research are: The influence of orientation on knowledge in groups that were not given orientation and orientation found that there was no significant difference in the average knowledge before and after orientation (p>0.05), this was because respondents had previously read first about MRI examinations on the internet and after reading the knowledge questionnaire their knowledge increased because after they filled out the questionnaire they asked the researchers what was stated in the knowledge questionnaire. The research suggests that the use of open MRI machines with wider bore diameters, along with patient-oriented practices such as allowing patients to see during the examination, can reduce anxiety.

Multidimensional numerical simulation of thermodynamic and oscillating gas flow processes of a Gifford-McMahon cryocooler

Abstract The Gifford-McMahon cryocoolers are considered to be prominent candidates for the cooling of high-temperature superconducting magnets, liquefaction of permanent gases, helium recondensation in magnetic resonance imaging machines, cooling of superconducting quantum interference device, etc. In this paper, multi-dimensional numerical simulation is performed to visualize the oscillating heat and fluid flow processes that happen in a mechanically driven GM cryocooler. Influence of the ideal gas equation and real gas equation of states on the cooling behaviour is explained. The minimum achievable refrigeration temperature of a uniform mesh regenerator is compared with a multi-mesh regenerator. It is noticed that a multi-mesh regenerator produces a lower refrigeration temperature as compared to a uniform mesh regenerator. In addition to this, a one-dimensional simulation is conducted and results are compared with multi-dimensional numerical simulation. The no-load temperature value calculated by the one-dimensional model and multi-dimensional model with ideal gas is lower than that of real gas equations. Additionally, the refrigerating capacity calculated by the one-dimensional model and multi-dimensional model with the ideal gas equation is higher than those of the real gas equation of state.

Overview of the Electromagnetic Optimization Literature of Superconducting Solenoidal Magnets and Coils

This article is a narrative and systematic review on the electromagnetic optimization literature of superconducting solenoidal magnets and coils. Superconducting solenoids are the basis of magnetic resonance imaging machines and superconducting energy storage systems. As the literature has evolved and many optimization techniques have been used, in this paper, we review the evolution of techniques used to achieve a defined field homogeneity, to reduce conductor's length, achieve a defined field intensity, increase stored energy, and optimize secondary aspects. We present chronologically, discuss and compare the referenced literature, which is also categorized in tables based on the optimization target. The tables present the optimization type, the used technique, the contribution of the paper, and the material. We discuss the existing literature gaps and the optimization techniques applied for designing the two most common machines, i.e., magnetic resonance imaging and superconducting magnetic energy storage devices, and we conclude that modern techniques are not used frequently, compared to techniques that predate the year 2000.

Malignant and Benign Peripheral Nerve Sheath Tumors in a Single Center: Value of Clinical and Ultrasound Features for the Diagnosis of Malignant Peripheral Nerve Sheath Tumor Compared With Magnetic Resonance Imaging.

This study aimed to investigate the combined use of ultrasonography and clinical features for the differentiation of malignant peripheral nerve sheath tumors (MPNST) from benign peripheral nerve sheath tumors (BPNST) and to compare the efficacy of ultrasonography with that of magnetic resonance imaging (MRI). This retrospective study included 28 MPNSTs and a control group of 57 BPNSTs. All patients underwent an ultrasound scan using the Logiq E9 (GE Health Care, Milwaukee, WI) or EPIQ7 equipment (Philips Medical System, Bothell, WA). A 3.0-T MRI machine (Ingenia; Philips Healthcare, Best, the Netherlands) was used for scanning, and conventional MRI was performed on different regions based on the patient's clinical situation. The following variables were evaluated: palpable mass, pain, nerve symptoms, maximum diameter, location, shape, boundary, encapsulation, echogenicity, echo homogeneity, presence of a cystic component, calcification, target sign, posterior echo, and intertumoral vascularity of the tumors. The diagnostic efficacy of ultrasonography and clinical factors was compared with that of MRI. Independent factors for predicting MPNST versus BPNST were also assessed. The parameters of location, shape, boundary, encapsulation, and vascularity were significantly different between MPNSTs and BPNSTs. Multiple logistic regression analysis showed that shape, boundary, and vascularity were independent predictors of MPNSTs. The sensitivity, specificity, and Youden index of the three clinical and ultrasound factors (shape, boundary, and vascularity) were 0.89, 0.81, and 0.69, respectively, whereas those of MRI were 0.71, 0.89, and 0.61, respectively. No significant differences in the area under the curve (AUC) of the three combined clinical and ultrasound factors and those of MRI were found (P > .05). MRI was useful in the differential diagnosis between MPNSTs and BPNSTs. However, the combination of clinical and ultrasound diagnoses can achieve the same effect as MRI, including shape, boundary, and vasculature.

Current role of portable MRI in diagnosis of acute neurological conditions.

Neuroimaging is an inevitable component of the assessment of neurological emergencies. Magnetic resonance imaging (MRI) is the preferred imaging modality for detecting neurological pathologies and provides higher sensitivity than other modalities. However, difficulties such as intra-hospital transport, long exam times, and availability in strict access-controlled suites limit its utility in emergency departments and intensive care units (ICUs). The evolution of novel imaging technologies over the past decades has led to the development of portable MRI (pMRI) machines that can be deployed at point-of-care. This article reviews pMRI technologies and their clinical implications in acute neurological conditions. Benefits of pMRI include timely and accurate detection of major acute neurological pathologies such as stroke and intracranial hemorrhage. Additionally, pMRI can be potentially used to monitor the progression of neurological complications by facilitating serial measurements at the bedside.

Peranan Magnetic Resonance Imaging (MRI) Lumbal dalam Penegakan Diagnosis Kasus Low Back Pain: Studi Kasus di Instalasi Radiologi Rumah Sakit Satya Negara Jakarta Utara

Background: Magnetic resonance imaging (MRI) is considered the best imaging for chronic low back pain because of high tissue contrast and no effect of ionizing radiation. The purpose of this study was to determine the management of Lumbar MRI examination with Low Back Pain Cases.Methods: The research used was a qualitative descriptive research method by collecting data by direct observation which was conducted in December 2022 at Satya Negara Hospital, North Jakarta. The research was conducted using direct observation methods, documentation and decision studies. The sample used was 1 patient.Results: The image results are strengthened by the expertise of a radiologist. The results of the study were obtained from the beginning of the patient's process of coming to radiology to perform a Lumbar MRI examination in the administration section until the examination was completed. Using a GE 1.5 T MRI machine and a whole spine coil. The sequences used are 3-plane location, calibration scan lumbar, Coronal T2, Sagittal T2, Sagittal T1, Sagittal T2 + FATSAT, Axial T2, Sagittal Myelography, Coronal Myelography.Conclusions: This study shows that Lumbar MRI image results and the doctor's expertise show that there is grade I spondylolithesis and L4-L5 spondyloarthrosis with disc protrusion. It’s mean that MRI can provide information for making a diagnosis.

Multicenter Standardization of Phase-Resolved Functional Lung MRI in Patients With Suspected Chronic Thromboembolic Pulmonary Hypertension.

Detection of pulmonary perfusion defects is the recommended approach for diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). This is currently achieved in a clinical setting using scintigraphy. Phase-resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is an alternative technique for evaluating regional ventilation and perfusion without the use of ionizing radiation or contrast media. To assess the feasibility and image quality of PREFUL-MRI in a multicenter setting in suspected CTEPH. This is a prospective cohort sub-study. Forty-five patients (64 ± 16 years old) with suspected CTEPH from nine study centers. 1.5 T and 3 T/2D spoiled gradient echo/bSSFP/T2 HASTE/3D MR angiography (TWIST). Lung signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between study centers with different MRI machines. The contrast between normally and poorly perfused lung areas was examined on PREFUL images. The perfusion defect percentage calculated using PREFUL-MRI (QDPPREFUL) was compared to QDP from the established dynamic contrast-enhanced MRI technique (QDPDCE). Furthermore, QDPPREFUL was compared between a patient subgroup with confirmed CTEPH or chronic thromboembolic disease (CTED) to other clinical subgroups. t-Test, one-way analysis of variance (ANOVA), Pearson's correlation. Significance level was 5%. Significant differences in lung SNR and CNR were present between study centers. However, PREFUL perfusion images showed a significant contrast between normally and poorly perfused lung areas (mean delta of normalized perfusion -4.2% SD 3.3) with no differences between study sites (ANOVA: P = 0.065). QDPPREFUL was significantly correlated with QDPDCE (r = 0.66), and was significantly higher in 18 patients with confirmed CTEPH or CTED (57.9 ± 12.2%) compared to subgroups with other causes of PH or with excluded PH (in total 27 patients with mean ± SD QDPPREFUL = 33.9 ± 17.2%). PREFUL-MRI could be considered as a non-invasive method for imaging regional lung perfusion in multicenter studies. 3 TECHNICAL EFFICACY: Stage 1.

Qualitative Classification of Proximal Femoral Bone Using Geometric Features and Texture Analysis in Collected MRI Images for Bone Density Evaluation.

The aim of this study was to use geometric features and texture analysis to discriminate between healthy and unhealthy femurs and to identify the most influential features. We scanned proximal femoral bone (PFB) of 284 Iranian cases (21 to 83 years old) using different dual-energy X-ray absorptiometry (DEXA) scanners and magnetic resonance imaging (MRI) machines. Subjects were labeled as "healthy" (T-score > -0.9) and "unhealthy" based on the results of DEXA scans. Based on the geometry and texture of the PFB in MRI, 204 features were retrieved. We used support vector machine (SVM) with different kernels, decision tree, and logistic regression algorithms as classifiers and the Genetic algorithm (GA) to select the best set of features and to maximize accuracy. There were 185 participants classified as healthy and 99 as unhealthy. The SVM with radial basis function kernels had the best performance (89.08%) and the most influential features were geometrical ones. Even though our findings show the high performance of this model, further investigation with more subjects is suggested. To our knowledge, this is the first study that investigates qualitative classification of PFBs based on MRI with reference to DEXA scans using machine learning methods and the GA.