Navigating Neural Landscapes: A Comprehensive Review of Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) Applications in Epilepsy

This review comprehensively explores the evolving role of neuroimaging, specifically magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS), in epilepsy research and clinical practice. Beginning with a concise overview of epilepsy, the discussion emphasizes the crucial importance of neuroimaging in diagnosing and managing this complex neurological disorder. The review delves into the applications of advanced MRI techniques, including high-field MRI, resting-state fMRI, and connectomics, highlighting their impact on refining our understanding of epilepsy's structural and functional dimensions. Additionally, it examines the integration of machine learning in the analysis of intricate neuroimaging data. Moving to the clinical domain, the review outlines the utility of neuroimaging in pre-surgical evaluations and the monitoring of treatment responses and disease progression. Despite significant strides, challenges and limitations are discussed in the routine clinical incorporation of neuroimaging. The review explores promising developments in MRI and MRS technology, potential advancements in imaging biomarkers, and the implications for personalized medicine in epilepsy management. The conclusion underscores the transformative potential of neuroimaging and advocates for continued exploration, collaboration, and technological innovation to propel the field toward a future where tailored, effective interventions improve outcomes for individuals with epilepsy.

The Accuracy of Breast Cancer Diagnostic Tools

Background Breast cancer (BC) remains a significant health concern, leading to illness and death among women globally. It is essential to detect BC early using imaging techniques that accurately reflect the final pathology, guiding suitable intervention strategies. Objectives This study aimed to evaluate the agreement between radiological findings and histopathological results in BC cases. Methods We conducted a retrospective review of breast core needle biopsies (CNBs) in women over a six-year period (2017-2022) at Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. The pathological diagnoses were compared with the findings from preceding radiological investigations. We also compared the tumour sizes in the resection specimens with their radiological counterparts. Results A total of 641 cases were included in the study. Ultrasound (US), mammography, and magnetic resonance imaging (MRI) yielded diagnostic accuracies of 85%, 77.9%, and 86.9%, respectively. MRI had the highest sensitivity at 72.2%, while US had the lowest at 61%. MRI provided the best agreement with the final resected tumor size. By contrast, mammography tended to overestimate the size (41.9%), and US most frequently underestimated it (67.7%). The connection between basal-like molecular subtypes and the Breast Imaging Reporting and Data System (BIRADS)-5 classifications was only statistically significant for MRI (p = 0.04). The luminal subtype was more likely to show speculation in mammography. Meanwhile, BIRADS-4 revealed a considerable number of benign pathologies across all the three modalities. Conclusions MRI demonstrated the highest accuracy, sensitivity, specificity, and positive predictive value (PPV) for diagnosing and estimating the tumor size. Mammography outperformed US in terms of sensitivity and yielded the highest negative predictive value (NPV). US, meanwhile, offered superior specificity, PPV, and accuracy. Therefore, combining these diagnostic methods could yield significant benefits.

Tibial Lateral Condyle Fracture After Cementless Oxford Unicompartmental Knee Arthroplasty (UKA): A Report of Four Cases

Cementless unicompartmental knee arthroplasty (UKA) has a lower rate of radiolucency in postoperative follow-up than cemented UKA. However, the rate of tibial plateau fracture, one of the complications, has been reported to be higher in cementless UKA than in cemented UKA. We report four cases of postoperative tibial lateral condyle fractures after cementless Oxford UKA. Four patients underwent cementless Oxford UKA. Immediate postoperative radiography and CT showed no fracture lines. At five to six weeks postoperatively, MRI showed a fracture line from the intersection of the longitudinal and transverse tibial osteotomies through the lateral pinhole to the end of the lateral tibial diaphysis. At three months, bone union was observed without surgical treatments. Lateral tibial fracture after cementless Oxford UKA has a good clinical course without the need for surgical intervention. Medial fractures should thus be more actively prevented. MRI is useful for less symptomatic tibial lateral condyle fractures.

Impact of Image Enhancement on the Radiomics Stability of Diffusion-Weighted MRI Images of Cervical Cancer

The diffusion-weighted imaging (DWI) technique is known for its capability to differentiate the diffusion of water molecules between cancerous and non-cancerous cervix tissues, which enhances the accuracy of detection. Despite the potential of DWI-MRI, its accuracy is limited by technical factors influencing in vivo data acquisition, thus impacting the quantification of radiomics features. This study aimed to measure the radiomics stability of manual and semi-automated segmentation on contrast limited adaptive histogram equalization (CLAHE)-enhanced DWI-MRI cervical images. Eighty diffusion-weighted MRI images were obtained from patients diagnosed with cervical cancer, and an active contour model was used to analyze the data. Radiomics analysis was conducted to extract the first statistical order, shape, and textural features with intraclass correlation coefficient (ICC) measurement. The results of the CLAHE segmentation approach showed a marked improvement when compared to the manual and semi-automated segmentation methods, with an ICC value of 0.990 ± 0.005 (p<0.05), compared to 0.864 ± 0.033 (p<0.05) and 0.554 ± 0.185 (p>0.05), respectively. The CLAHE segmentation displayed a higher level of robustness than the manual groups in terms of the features present in both categories. Thus, CLAHE segmentation is owing to its potential to generate radiomics features that are more durable and consistent.

Eye Size and Shape in Relation to Refractive Error in Children: A Magnetic Resonance Imaging Study

Purpose

The purpose of this study was to determine the association between eye shape and volume measured with magnetic resonance imaging (MRI) and optical biometry and with spherical equivalent (SE) in children.

Methods

For this study, there were 3637 10-year-old children from a population-based birth-cohort study that underwent optical biometry (IOL-master 500) and T2-weighted MRI scanning (height, width, and volume). Cycloplegic refractive error was determined by automated refraction. The MRI images of the eyes were segmented using an automated algorithm combining atlas registration with voxel classification. Associations among optical biometry, anthropometry, MRI measurements, and RE were tested using Pearson correlation. Differences between refractive error groups were tested using ANOVA.

Results

The mean volume of the posterior segment was 6350 (±680) mm3. Myopic eyes (SE ≤ -0.5 diopters [D]) had 470 mm3 (P < 0.001) and 970 mm3 (P < 0.001) larger posterior segment volume than emmetropic and hyperopic eyes (SE ≥ +2.0D), respectively. The majority of eyes (77.1%) had an oblate shape, but 47.4% of myopic eyes had a prolate shape versus 3.9% of hyperopic eyes. The correlation between SE and MRI-derived posterior segment length (r -0.51, P < 0.001) was stronger than the correlation with height (r -0.30, P < 0.001) or width of the eye (r -0.10, P < 0.001).

Conclusions

In this study, eye shape at 10 years of age was predominantly oblate, even in eyes with myopia. Of all MRI measurements, posterior segment length was most prominently associated with SE. Whether eye shape predicts future myopia development or progression should be investigated in longitudinal studies.

Lateral Lumbar Spinal Stenosis: Associations With the Oswestry Disability Index, Visual Analogue Scale, and Magnetic Resonance Imaging

Introduction Degenerative lumbar spinal stenosis is a communal problem in the sixth decade of life involving L4/L5 and L5/S1 levels. Lateral spinal stenosis is often underestimated because of no established relationship between the clinical symptoms and MRI findings. We conducted a study to establish an association between the degree of anatomical lateral stenosis, posterior disc height, and disc degeneration from MRI with the daily disability and pain severity for lateral lumbar spinal stenosis. Methods This was a cross-sectional study involving 121 patients with distinct clinical symptoms of lateral lumbar spinal stenosis evaluated from February 2018 to December 2019. The clinical data were evaluated using the Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS), while magnetic resonance imaging (MRI) was assessed qualitatively for the anatomical gradation of lateral spinal stenosis, the magnitude of posterior disc height, and the extent of disc degeneration. Statistical analysis for the correlation between posterior disc height and ODI and VAS scores was evaluated using Pearson's correlation test via SPSS version 23.0 (IBM Inc., Armonk, New York), and the association between the extent of lateral stenosis and disc degeneration on MRI with ODI and VAS scores was determined by the Fisher Exact Test via STATA version 14.0 (StataCorp LLC, College Station, Texas). The association was considered statistically significant with a P-value of less than 0.05. Results The analysis of 121 patients showed the mean age of the patients was 58.7 ± 7.1 years old. The number of female patients was higher compared to male patients, 52.9% and 47.1%, respectively. 97.5% of the patients were married or cohabiting, and 76.0% had an abnormal body mass index. The mean score of ODI and VAS was 62.2 ± 10.7% and 79.3 ± 8.6 respectively. 49.6% of the patient presented with a crippling disability with ODI assessment, while 59.5% presented with high pain intensity with VAS assessment. MRI assessment of anatomical grading lateral stenosis of L4/L5 level revealed that 45.5% of the patients had grade 2 lateral recess stenosis, 63.6% had grade 2 foraminal stenosis, and 44.6% had extraforaminal stenosis. L5/S1 level analysis showed that 43.0% had grade 2 lateral recess stenosis, 62.0% had grade 2 foraminal stenosis, and 29.8% had extraforaminal stenosis. 64.5% of patients had grade 4 disc degeneration of L4/L5 with mean posterior disc height of 7.0mm ±1.7mm while 59.5% had grade 4 disc degeneration of L5/S1 with mean posterior disc height of 6.3mm ±1.8mm. However, no statistically significant association between clinical symptoms and MRI findings was found.  Conclusions There was no significant association between the clinical symptoms of pain and disability and the MRI findings for the anatomical gradation of lateral spinal stenosis, the magnitude of posterior disc height, and the extent of disc degeneration. A comprehensive clinical evaluation remains essential for an accurate diagnosis, emphasizing the necessity of appropriately correlating MRI findings with their clinical significance.

High-Resolution Imaging Insights into Shoulder Joint Pain: A Comprehensive Review of Ultrasound and Magnetic Resonance Imaging (MRI)

Shoulder joint pain is a complex and prevalent clinical concern affecting individuals across various ages and lifestyles. This review delves into the pivotal role of high-resolution imaging techniques, namely ultrasound and magnetic resonance imaging (MRI), in the comprehensive assessment and management of shoulder joint pain. We explore the anatomical foundations of the shoulder, common etiologies of pain, and the significance of precise diagnosis. High-resolution imaging facilitates the identification of various shoulder pathologies and is crucial in treatment planning, surgical interventions, and long-term prognosis assessment. We examine emerging technologies, discuss challenges and limitations, and chart potential future developments, emphasizing the ongoing evolution of imaging in this critical healthcare domain. In conclusion, high-resolution imaging is an indispensable tool, continually advancing to meet the diagnostic and therapeutic needs of individuals grappling with shoulder joint pain.

Malignant Solitary Fibrous Tumor of the Inguinal Region: A Case Report

A solitary fibrous tumor (SFT) is a rare spindle cell neoplasm in adults, usually found in the pleural and thoracic cavities. We report an interesting case of a malignant solitary fibrous tumor in a 64-year-old male who presented with a history of swelling in his right inguinal region that gradually increased in size during the past three years. Computed tomography (CT) and magnetic resonance imaging (MRI) scans of the abdomen and pelvis showed a rounded solid mass originating from the right inguinal canal suggestive of sarcoma. Elective excision of the mass was done under general anesthesia with histopathology confirming the diagnosis of high-grade spindle cell sarcoma in keeping with a malignant solitary fibrous tumor. Postoperatively, the patient had no complications and was discharged on postoperative day 4. The patient was then treated with radiotherapy. He remained free of recurrence for two years postoperatively.

Rare Encounter of Cerebral Fat Embolism Post Motor Vehicle Accident: A Case Report

Fat embolism syndrome (FES) is known to occur when fat macroglobules get embolized into the blood circulation, whereby they then get dispersed out to multiple organs including the brain. It's typically diagnosed when the patient sustains a neurological dysfunction, respiratory insufficiency, and petechial rash, the classical triad of FES. Cerebral fat embolism occurrence is rarely seen. In this case report, a 20-year-old male was admitted due to a closed left midshaft femur fracture from a motor vehicle accident, and sustained cerebral manifestation of fat embolism syndrome 32 hours post the incident. It was noted that the patient had the classical triad of FES and intubation was done for airway protection. MRI revealed features of cerebral fat embolism. Interlocking nail fixation of the left femur was done for this patient on day three after admission. On day 15 post trauma, the patient was successfully extubated. Adequate supportive management was given and the patient's prognosis improved. As a practitioner, it is important to recognize and diagnose cerebral fat embolism as early as possible so as to have a much better outcome and to avoid any unnecessary investigation.

A Case Report of Asherman's Syndrome With Abnormal Placenta Implantation (Intrauterine Adhesion)

We report the case of a 28-year-old patient with a partial placental insertion on an intrauterine adhesion diagnosed at 20 weeks' gestation. The increasing incidence of intrauterine adhesions during the last decade has been attributed to the rising number of uterine surgeries in the fertile population and better imaging studies facilitating diagnosis. Although uterine adhesions during pregnancy are generally considered benign, the existing evidence is conflicting. The obstetric risks in these patients are unclear, but higher numbers of placental abruption, preterm premature rupture of membranes (PPROM), and cord prolapse have been reported. Thus, a prenatal diagnosis should prompt close feto-maternal observation. Surgical resection should be offered to patients with adhesions found prior to pregnancy.

Insights Into Meningioma Visibility on Arterial Spin Labeling MRI: Location Outweighs Size

Background Arterial Spin Labeling (ASL) MRI is a non-invasive imaging technique with potential applications for assessing meningiomas. This retrospective study aimed to investigate the impact of tumor location, size, age, and sex on the ASL visibility of meningiomas. Methods We retrospectively analysed 40 patients with meningiomas, who underwent 3 Tesla MRI examinations using a three-dimensional (3D) pulsed ASL technique. Tumor location was categorized as around the skull base or elsewhere, and size was determined by the area in the transverse plane. Results Our findings revealed that meningiomas around the skull base were significantly more likely to be ASL-visible compared to those located elsewhere (p < 0.001), whereas tumor size, age, and sex did not show a significant correlation with ASL visibility. This observation suggests that tumor location is a critical factor in determining the visibility of meningiomas on ASL MRI. Conclusion The results contribute to a better understanding of ASL visibility in meningiomas, highlighting the importance of tumor location over size. Further research, including larger cohorts and additional factors, such as histological variants, is needed to expand upon these findings and explore their clinical implications.

Minor Salivary Gland Polymorphous Adenocarcinoma With Local Recurrence After Seven Years: A Case Report

Polymorphous adenocarcinoma is a rare neoplasm of the minor salivary glands with an indolent behavior. Here, we report and describe the computed tomography (CT) and magnetic resonance imaging (MRI) of polymorphic adenocarcinoma in a 69-year-old patient who presented with local recurrence seven years after the initial treatment. On contrast CT, the primary lesion appeared heterogeneous and invaded the pterygopalatine fossa and the sphenopalatine foramen. The recurrent lesion on MRI showed a hypointense signal on the T1-weighted sequence, a hyperintense signal on the T2-weighted sequence, and heterogeneous enhancement with contrast. The patient underwent a new surgery for lesion resection and is currently under clinical and radiological follow-up. It is recommended to follow patients for at least 15 years after diagnosis, as local recurrences can occur up to 10 years after the initial treatment.

Characterizing Various Posterior Fossa Tumors in Children and Adults With Diffusion-Weighted Imaging and Spectroscopy

Background The posterior fossa is situated between the tentorium cerebelli above and the foramen magnum below. Vital structures like the cerebellum, the pons, and the medulla are situated within it; hence, tumors within the posterior fossa are considered one of the most critical brain lesions. Children are more likely to develop posterior fossa tumors than adults. Diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) sequences along with the conventional MRI help in providing additional information in the characterization of the various posterior fossa tumors. We hereby present a series of 30 patients with clinically suspected posterior fossa masses who underwent preoperative MRI. Objectives This study aims to differentiate the neoplastic from non-neoplastic posterior fossa mass by evaluating the diffusion restriction pattern on DWI, quantifying the apparent diffusion coefficient (ADC) map in various posterior fossa tumors, and comparing the different metabolites of various posterior fossa tumors on MRS. Results Out of the 30 patients with posterior fossa lesions, 18 were males and 12 were females. Eight of them were in the pediatric age group, while twenty-two of them were adults. Metastasis was the most common posterior fossa lesion in our study sample and was found in six patients (20%), followed by vestibular schwannomas (17%) and arachnoid cysts (13%), meningiomas, medulloblastoma, and pilocytic astrocytoma (10% each) and epidermoid, ependymoma, and hemangioblastoma (7% each). The mean ADC value of benign tumors was higher than that of malignant tumors, and this difference was found to be significant (p = 0.012). The cut-off ADC value 1.21x 10^-3mm²/s had a sensitivity of 81.82% and specificity of 80.47%. MRS metabolites played an additional role in differentiating benign from malignant tumors. Conclusion A combination of conventional MRI, DWI, ADC values, and MRS metabolites showed good diagnostic accuracy to differentiate between the various posterior fossa neoplastic tumors both in adults and children.

Age-Dependent Changes in the Water Content and Optical Power of the In Vivo Mouse Lens Revealed by Multi-Parametric MRI and Optical Modeling

Purpose

The purpose of this study was to utilize in vivo magnetic resonance imaging (MRI) and optical modeling to investigate how changes in water transport, lens curvature, and gradient refractive index (GRIN) alter the power of the mouse lens as a function of age.

Methods

Lenses of male C57BL/6 wild-type mice aged between 3 weeks and 12 months (N = 4 mice per age group) were imaged using a 7T MRI scanner. Measurements of lens shape and the distribution of T2 (water-bound protein ratios) and T1 (free water content) values were extracted from MRI images. T2 values were converted into the refractive index (n) using an age-corrected calibration equation to calculate the GRIN at different ages. GRIN maps and shape parameters were inputted into an optical model to determine ageing effects on lens power and spherical aberration.

Results

The mouse lens showed two growth phases. From 3 weeks to 3 months, T2 decreased, GRIN increased, and T1 decreased. This was accompanied by increased lens thickness, volume, and surface radii of curvatures. The refractive power of the lens also increased significantly, and a negative spherical aberration was developed and maintained. Between 6 and 12 months of age, all physiological, geometrical, and optical parameters remained constant, although the lens continued to grow.

Conclusions

In the first 3 months, the mouse lens power increased as a result of changes in shape and in the GRIN, the latter driven by the decreased water content of the lens nucleus. Further research into the mechanisms regulating this decrease in mouse lens water could improve our understanding of how lens power changes during emmetropization in the developing human lens.

Foreign Body Reaction After Hip Augmentation Surgery: A Case Report

Hip augmentation cosmetic surgery is an increasingly popular procedure for patients seeking to enhance their body contour and improve their self-image. Despite its benefits, complications can arise, including the rare but serious foreign body reaction (FBR). We present a case of a 32-year-old patient with a history of hip augmentation cosmetic surgery who presented with persistent hip pain. A comprehensive clinical evaluation, followed by magnetic resonance imaging (MRI), revealed a foreign body reaction associated with the cosmetic augmentation procedure. This case report aims to describe the clinical presentation, diagnosis, and management of FBR in patients who have undergone hip augmentation cosmetic surgery. We will also discuss potential risk factors, prevention strategies, and the importance of early detection and intervention to avoid severe complications and improve patient outcomes. By sharing this case, we aim to raise awareness among healthcare professionals about this rare but significant complication of foreign body reaction and emphasize the need for close monitoring and timely intervention in patients who have undergone hip augmentation cosmetic surgery.

The Spectrum of Vessel Wall Imaging (VWI) Findings in COVID-19-Associated Neurological Syndromes: A Review

Since the start of the pandemic, there have been extensive studies from all over the world reporting on coronavirus disease 2019 (COVID-19)-associated neurological syndromes. Although initially thought of as primarily a respiratory pathogen, it became increasingly clear that the virus does have other systemic manifestations, including on the neurological system. Since then, the discovery of the many neuroimaging features of COVID-19-associated neurological syndromes have puzzled researchers and physicians in terms of interpretation, and how best to manage these findings to benefit patients. We sought to review the neuroimaging findings of COVID-19-associated neurological syndromes, particularly the vessel wall imaging (VWI) features, in the hope of finding a common feature that would better guide physicians in terms of further management of this group of patients. We will also look into the potential pitfalls of interpreting the VWI findings in these patients.

Distributive Shock in Erythrodermic Psoriasis Treated With Norepinephrine and Vasopressin: A Case Report

Distributive shock and hypothermia are two unusual and potentially fatal complications of erythroderma, a rare complication of psoriasis. Very few cases of erythrodermic psoriasis have been reported, particularly in the United States, which may pose a diagnostic challenge for internists. We present a case report of distributive hemodynamic instability and hypothermia in a 61-year-old female who initially presented with acute altered mental status thought to be related to an infectious etiology.

Development of a Synthetic Biosensor for Chemical Exchange MRI Utilizing In Silico Optimized Peptides

Chemical Exchange Saturation Transfer (CEST) magnetic resonance imaging (MRI) has been identified as a novel alternative to classical diagnostic imaging. Over the last several decades, many studies have been conducted to determine possible CEST agents, such as endogenously expressed compounds or proteins, that can be utilized to produce contrast with minimally invasive procedures and reduced or non-existent levels of toxicity. In recent years there has been an increased interest in the generation of genetically engineered CEST contrast agents, typically based on existing proteins with CEST contrast or modified to produce CEST contrast. We have developed an in-silico method for the evolution of peptide sequences to optimize CEST contrast and showed that these peptides could be combined to create de novo biosensors for CEST MRI. A single protein, superCESTide 2.0, was designed to be 198 amino acids. SuperCESTide 2.0 was expressed in E. coli and purified with size-exclusion chromatography. The magnetic transfer ratio asymmetry (MTR asym ) generated by superCESTide 2.0 was comparable to levels seen in previous CEST reporters, such as protamine sulfate (salmon protamine, SP), Poly-L-Lysine (PLL), and human protamine (hPRM1). This data shows that novel peptides with sequences optimized in silico for CEST contrast that utilizes a more comprehensive range of amino acids can still produce contrast when assembled into protein units expressed in complex living environments.

A Report of Two Cases of Malignant Tumor of the Maxillary Sinus Diagnosed Using Fine-Needle Aspiration Cytology

Primary and metastatic malignancies arising in the sinuses are rare and histologically diverse. The role of fine-needle aspiration cytology (FNAC) and the cytomorphologic characteristics of these tumors have not been specifically addressed. We described two cases of suspected malignant maxillary sinus tumors in 85- and 90-year-old patients with comorbid conditions, both of whom underwent tissue biopsies that failed to yield a definitive diagnosis. We performed FNAC after imaging confirmed that the malignant tumors were outside the maxillary sinus. The 85- and 90-year-old patients were diagnosed with squamous cell carcinoma (SCC) and adenocarcinoma, respectively. In the latter, the cell block method was used to prepare the specimen, rendering individual cells identifiable. Atypia of the histological structure was confirmed without the influence of cell duplication, a known weakness of FNAC. Thus, the diagnosis was made quickly. We believe that FNAC would be utilized more frequently for the definitive diagnosis of sinonasal tumors as the technique and diagnostic technology improve further.

Dyke-Davidoff-Masson Syndrome: A Case Report

Dyke-Davidoff-Masson syndrome (DDMS) is a rare neurological entity that is predominantly seen in childhood. Here, we present the case of a 13-year-old girl who was brought to the pediatric ward for general examination with a previous history of seizures, speech difficulty, facial deviation, and progressive left-sided hemiparesis that started at the age of two, followed by delayed developmental milestones. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain showed right cerebral hemiatrophy, ventriculomegaly, hyperpneumatization of the sinus, the decreased caliber of cortical veins, and skull thickening on the right were all characteristic findings of DDMS. Based on the history, clinical presentation, and imaging findings from CT and MRI, DDMS was confirmed. Identifying DDMS in a clinical setting can be challenging because of low awareness of the condition and varied clinical presentations. Although CT and MRI imaging are the gold standards in diagnosing DDMS, the early manifestations of the disease cannot be well-appreciated on a CT and would likely require an MRI. Since there is no standardized protocol for managing DDMS, the treatment is primarily symptomatic. Early identification and diagnosis of the syndrome are essential to aid the child's mental and physical development through a multidisciplinary approach. There is also a need to improve awareness of DDMS so that the condition can be considered a potential differential diagnosis amongst other similar conditions and does not get misdiagnosed. The lack of a proper protocol for the management of DDMS prompts more research for a better understanding and early identification of the condition.

Diagnosis and management of extramedullary plasmacytoma in nasal cavity: Clinical experience and literature review

Nasal extramedullary plasmacytoma (EMP) is a rare plasma cell tumor that occurs in the soft tissue of the nasal cavity, and its imaging characteristics are still unclear. The purpose of this study was to investigate the clinical features, imaging findings, treatment, survival analysis, and prognosis of nasal EMP, and to provide a systematic review of the patients we treated and the published literature. A 45-year-old female patient who presented with epistaxis with nasal obstruction was recommended for magnetic resonance imaging to assess the nature of the lesion. On magnetic resonance imaging, abnormal signal shadow can be seen in the right nasal cavity. Diffusion weighted imaging showed signal of the lesion was significantly limited, presenting high signal, with a low apparent dispersion coefficient, and the lesion was significantly enhanced on contrast-enhanced scan. Combined with the clinical manifestations of the patient, who was initially considered to have a hemangioma. She underwent endoscopic nasal surgery under general anesthesia to remove the mass, and the final pathology confirmed it was EMP. However, the final pathology confirmed EMP. Five months later, the patient came to our hospital for follow-up and underwent fluorine-18-fluorodeoxyglucose/positron emission tomography/computed tomography scan, which showed no recurrence of the lesion and no transformation of multiple myeloma. The nasal EMP imaging findings were mostly soft tissue masses with uniform density or signal, which were significantly enhanced by enhancement scan, high signal on diffusion weighted imaging and low signal on apparent dispersion coefficient. Immunohistochemical staining for CD38, CD138, and CD79a was positive in most of the cases evaluated, while CD20 and CD10 were negative. The absence of dilated features, infiltrative features and the presence of significant contrast enhancement may be relatively specific imaging findings of nasal EMP. The prognosis of nasal EMP is good, and recurrence, metastasis, and transformation into multiple myeloma are rare. Because the lesions are sensitive to radiotherapy, surgical resection combined with radiotherapy is a more effective treatment.

Linear structural features of Wilson's disease and its correlation with neurological symptoms

To measure the linear structure of the brain in patients with Wilson's disease (WD) and analyze its correlation with neurological symptoms. A total of 174 patients diagnosed with WD were enrolled. According to the type of clinical presentation, the patients with WD were divided into two groups: neurological (NWD) and hepatic (HWD). Sixty healthy volunteers were assigned to a control group. All patients with WD and healthy controls underwent brain magnetic resonance imaging (MRI). The severity of the neurological symptoms was assessed using the Burke Fahn Marsden Movement subscale (BFM-M). Linear brain measurements were performed using T1-weighted MRI scans of all the patients, and the correlation between these linear indices and BFM-M score was investigated. The Huckman index, third ventricle width, and sulcus width of the NWD group were significantly higher than those of the HWD and control groups (P < .05). The frontal horn index, ventricular index, and lateral ventricular body width index of the NWD group were significantly lower than those of the HWD and control groups (P < .05). The Huckman index and third ventricle width of the HWD group were higher than those of the control group (P < .05), whereas the body width index of the lateral ventricle was lower than that of the control group (P < .05). The BFM-M score correlated with the Huckman index (r = 0.29, P < .05), third ventricle width (r = 0.426, P < .001), and lateral ventricular body width index (r = -0.19, P < .05). This study demonstrated significant changes in the linear structure of patients with WD. Linear brain measurement analysis could be used as a potential method to assess the severity of neurological symptoms in WD.

Evaluation of Normal Inferior Vena Cava Diameters in the Indian Adult Population by Computed Tomography

Background The imaging evaluation of inferior vena cava (IVC) diameters is essential for the estimation of vena caval pathologies and can also detect early hypovolemic shock. There are very few studies on normal IVC diameters on CT scan done in foreign countries, and none done in the Indian population. Aims The goal of this research is to assess the normal IVC diameter in the Indian adult population by performing a CT scan of the abdomen. Material and methods In this study, CT scans of 200 individuals (aged 19-83) without any circulatory and vascular disorders were analyzed retrospectively. The anteroposterior (AP) and transverse diameters of the IVC were measured at the level of the renal vein and at the level 2 cm proximal to insertion in the heart (usual area of measurement on ultrasonography). Results The study discovered normal adult mean AP and transverse dimensions of the IVC at the level of the renal vein as 16.3 ± 2.9 mm and 25.8 ± 3.5 mm, respectively, and 16.9 + 3.2 mm and 26.2 + 3.6 mm at the level 2 cm proximal to its insertion in the right atrium. Conclusions In this study, the normal morphometric dimensions of the IVC in the Indian adult population were established. The diameters of the IVC and the age of the participants in our study had no statistically significant correlation, however, the IVC changes its cross-sectional area and diameter due to changes in venous pressure and blood pressure and hence is a highly compliant vessel. The results of the study will be used as baseline data for the assessment of IVC disorders.

Acute Disseminated Encephalomyelitis Following Thoracic Endovascular Aortic Repair

Acute disseminated encephalomyelitis (ADEM) is a central nervous system demyelinating condition. The postulated etiology is an autoimmune reaction, however, the mechanistic details are yet unknown. While infection and immunization are the most prevalent precipitating causes of ADEM, we postulate that radiopaque contrast material might have played a role as an immunological trigger. This presentation is unusual and has not been recorded so far. This case also emphasizes the challenges involved in evaluating emerging neurological problems following a period of intubation/sedation among these patients. We present a patient who passed away due to the manifestations of ADEM following admission to the intensive care unit after thoracic endovascular aortic repair for type B aortic dissection. Magnetic resonance imaging (MRI) performed following multiple attempts at sedation weaning demonstrated typical features of this condition. Clinicians and radiologists should be diligent and consider ADEM as a differential diagnosis when treating patients who present with neurological symptoms following radiological interventional procedures and have a high index suspicion to reduce mortality and achieve satisfactory clinical outcomes.

Deformation-Compensated Learning for Image Reconstruction Without Ground Truth

Deep neural networks for medical image reconstruction are traditionally trained using high-quality ground-truth images as training targets. Recent work on Noise2Noise (N2N) has shown the potential of using multiple noisy measurements of the same object as an alternative to having a ground-truth. However, existing N2N-based methods are not suitable for learning from the measurements of an object undergoing nonrigid deformation. This paper addresses this issue by proposing the deformation-compensated learning (DeCoLearn) method for training deep reconstruction networks by compensating for object deformations. A key component of DeCoLearn is a deep registration module, which is jointly trained with the deep reconstruction network without any ground-truth supervision. We validate DeCoLearn on both simulated and experimentally collected magnetic resonance imaging (MRI) data and show that it significantly improves imaging quality.

Imaging techniques to study diabetic bone disease

PURPOSE OF REVIEW

This review article presents the most recent research on bone fragility in individuals with diabetes from a medical imaging perspective.

RECENT FINDINGS

The widespread availability of dual-energy X-ray absorptiometry (DXA) and trabecular bone score (TBS) software has led to recent assessments of bone fragility with this texture parameter in several studies of type 2 diabetes mellitus (T2D), but in few of type 1 diabetes mellitus (T1D). Although most studies show a trend of reduced TBS values in T2D independent of areal bone mineral density (aBMD) of the lumbar spine, some studies also show the limitations of TBS in both T2D and T1D. Given the limitations of DXA to assess bone strength and investigate the etiology of bone fragility in diabetes, more investigators are incorporating three-dimensional (3D) medical imaging techniques in their studies. Recent use of 3D medical imaging to assess bone fragility in the setting of diabetes has been mostly limited to a few cross-sectional studies predominantly incorporating high-resolution peripheral quantitative computed tomography (HR-pQCT). Although HR-pQCT studies indicate higher tibial cortical porosity in subjects with T2D, results are inconsistent in T1D due to differences in study designs, sample sizes, and subject characteristics, among other factors. With respect to central CT, recent studies support a previous finding in the literature indicating femoral neck geometrical impairments in subjects with T2D and provide encouraging results for the incorporation of finite element analysis (FEA) to assess bone strength in studies of T2D. In the recent literature, there are no studies assessing bone fragility in T1D with QCT, and only two studies used pQCT reporting tibial and radial impairments in young women and children with T1D, respectively. Magnetic resonance imaging (MRI) has not been recently used in diabetic studies of bone fragility.

SUMMARY

As bone fragility in diabetes is not explained by DXA-derived aBMD and given the limitations of cross-sectional studies, it is imperative to use 3D imaging techniques for longitudinal assessments of the density, quality, and microenvironment of bone to improve our understanding of the effects of diabetes on bone and reduce the risk of fracture in this large and vulnerable population of subjects with diabetes.

Acute Onset Focal Epilepsy Mimicking Stroke

A wide range of acute neurological disorders may present with symptoms similar to a stroke, so-called 'stroke mimics'. Migraine aura and seizures account for the most extensive stroke mimics population. A large number of patients with a definite stroke mimics diagnosis (most commonly those with psychiatric disorders or seizures) had been treated with IV alteplase without adverse related events. We report a case of a man aged 70 years admitted to the emergency room because of acute onset of delirium and a loss of strength in the left arm (National Institutes of Health Stroke Scale {NIHSS}: 10), severe hyponatremia (127 mEq/L), and no evidence of intracranial arterial occlusion at CT scan. He was eligible for intravenous thrombolysis and, after treatment, neurological symptoms improved (NIHSS: 2). The subsequent appearance of “clonus” in the left lower limb, the persistence of hyponatremia, and the presence of electroencephalogram (EEG) abnormalities led to the clinical suspicion of focal motor-onset seizure with impaired awareness. The patient was treated successfully with anti-seizure medications (ASMs): lacosamide 200 mg IV during the acute setting care, followed by oral lacosamide 200 mg bis in die (BID). Since two other focal seizures occurred, brivaracetam 25 mg BID has been added in therapy with subsequent clinical discontinuance and EEG normalization. Two consecutive magnetic resonance imaging (MRI) examinations showed several cortical lesions restricted in high signal in diffusion‐weighted imaging (DWI) which corresponding to T2‐weighted and fluid‐attenuated inversion recovery (FLAIR) hyperintensities, but without lesions evidence in apparent diffusion coefficient (ADC) map. These radiological changes disappeared at a follow-up MRI performed 20 days after the symptoms’ onset. The patient fully recovered was discharged home without developing pharmacological adverse events. In this case, MRI provided an opportunity for early identification of seizure-related alterations. Hence, we discuss how prospective MRI studies during seizures and interictal period would contribute to defining the relationship between the electroclinical characteristics and MRI alteration patterns, and therefore, the potential role of MRI in the differential diagnosis between seizures and stroke mimic.

Transcranial MR-Guided Histotripsy System

Histotripsy has been previously shown to treat a wide range of locations through excised human skulls in vitro. In this article, a transcranial magnetic resonance (MR)-guided histotripsy (tcMRgHt) system was developed, characterized, and tested in the in vivo pig brain through an excised human skull. A 700-kHz, 128-element MR-compatible phased-array ultrasound transducer with a focal depth of 15 cm was designed and fabricated in-house. Support structures were also constructed to facilitate transcranial treatment. The tcMRgHt array was acoustically characterized with a peak negative pressure up to 137 MPa in free field, 72 MPa through an excised human skull with aberration correction, and 48.4 MPa without aberration correction. The electronic focal steering range through the skull was 33.5 mm laterally and 50 mm axially, where a peak negative pressure above the 26-MPa cavitation intrinsic threshold can be achieved. The MR compatibility of the tcMRgHt system was assessed quantitatively using SNR, B0 field map, and B1 field map in a clinical 3T magnetic resonance imaging (MRI) scanner. Transcranial treatment using electronic focal steering was validated in red blood cell phantoms and in vivo pig brain through an excised human skull. In two pigs, targeted cerebral tissue was successfully treated through the human skull as confirmed by MRI. Excessive bleeding or edema was not observed in the peri-target zones by the time of pig euthanasia. These results demonstrated the feasibility of using this preclinical tcMRgHt system for in vivo transcranial treatment in a swine model.

The V-Localizer for Stereotactic Guidance

Image-guidance for frame-based stereotaxis is facilitated by incorporating three to four N-localizers or Sturm-Pastyr localizers into a stereotactic frame. An extant frame that incorporates only two N-localizers violates the fundamental principle of the N-localizer, which requires three non-colinear points to define a plane in three-dimensional space. Hence, this two N-localizer configuration is susceptible to error. The present article proposes the V-localizer that comprises multiple diagonal bars to provide four or more non-colinear points to minimize error.

Role of MRI in Differentiating Various Posterior Cranial Fossa Space-Occupying Lesions Using Sensitivity and Specificity: A Prospective Study

BACKGROUND

Any abnormal space-occupying posterior fossa lesion may directly involve the vital structures like the brain stem, cranial nerves, cerebellum, vertebrobasilar artery, and venous sinuses, which makes the surgical approach and total excision very difficult. Hence for these reasons, precise evaluation of posterior fossa lesion with MRI is a must to visualize the vital structures, which helps in planning and safe surgery.  Objective: This study aimed to evaluate the added value of diffusion-weighted imaging and magnetic resonance spectroscopy in the localization, extension, characterization, differentiation of various posterior fossa space-occupying lesions, and correlating with the histopathological result.

MATERIALS AND METHODS

This prospective study comprised of 40 patients who were suspected with posterior fossa space-occupying lesions on basis of clinical features or on CT scan. All patients were evaluated using conventional as well as newer MRI techniques using Siemens 1.5 Tesla MRI scanner (Siemens Medical System, Erlangen, Germany). Diffusion-weighted imaging (DWI) was done in all patients and magnetic resonance spectroscopy (MRS) was done in 27 patients. Based on the MRI findings, various posterior fossa lesions were classified as neoplastic or non-neoplastic. The neoplastic lesions were further classified as benign and malignant. The MRI findings were correlated with histopathological findings or follow-up.

STATISTICAL ANALYSIS

Independent sample t-test was used to compare the mean apparent diffusion coefficient (ADC) values of various posterior fossa space-occupying lesions. Receiver operating characteristic (ROC) curve analysis was done to determine the optimal cut-off mean ADC values and choline/creatinine (Cho/cr) ratios for various benign and malignant posterior fossa tumors.

RESULTS

Of 40 patients with posterior fossa lesions, 23 were males and 17 were females with a mean age of 34.67±1.93[SD] years. Metastases were the most common posterior fossa lesions in our study sample and found in seven patients (17.5%) followed by vestibular schwannomas and brainstem gliomas in five patients (12.5%) each, demyelinating lesion in four patients (10%), tubercular abscess in three patients (7.5%), hemangioblastoma, tuberculoma, arachnoid cyst, epidermoid cyst, pilocytic astrocytoma, low-grade glioma in two patients (5%) each, meningioma, medulloblastoma, pyogenic abscess and high-grade glioma in one patient (2.5%) each. The mean ADC value of benign tumors was higher than that of malignant tumors and this difference was found to be significant (p = 0.019). The cut-off ADC value 1.022 x 10^-3mm²/s had a sensitivity of 78.6% and specificity of 66.7%. MRS played important role in differentiating neoplastic from non-neoplastic lesions and benign from malignant tumors. The cut-off Cho/cr ratio of 1.25 had a sensitivity of 66.7%, specificity of 85.7% to differentiate benign from malignant tumors.

CONCLUSION

Conventional MRI sequences able to diagnose most of the benign-appearing lesions of posterior fossa, however, adding advanced MRI sequences like diffusion-weighted imaging and MR spectroscopy helps us to differentiate and diagnose various posterior fossa lesions even closer to the actual histopathological diagnosis.

Added Value of Three-Plane Multiecho Fast Field Echo MRI Sequence in the Evaluation of Acute Spinal Trauma Using Sensitivity: A Prospective Study

Background

Multiecho fast field echo (mFFE) MRI sequence provides added value to the conventional MR imaging in evaluation of acute spinal trauma, especially for detecting spinal cord hemorrhage which is a best predictor for patient prognosis.

Objective

This study aims to evaluate the diagnostic efficacies of three-plane mFFE MRI sequence along with the conventional MRI sequences in acute spinal trauma patients using sensitivity. 

Materials and methods

This prospective study comprised of 48 patients of acute spinal trauma. The neurological deficit of acute spinal trauma patients assessed according to the American Spine Injury Association (ASIA) scale. The correlation between the various MRI findings of acute spinal cord injury and neurological deficits were compared with the Chi-square test.

Results

Of 48 patients of acute spinal trauma, 36 males and 12 females with a mean age of 38.71±1.42 [SD] years. 22 (45.8%) patients had cord edema with a mean length of was 3.45±5.52 [SD] cm. The mean percentage of spinal canal compromisation was 39.47±25.47 [SD] and spinal cord compression 18.1±24.4 [SD]. There was statistical significance between the ASIA impairment scale and spinal canal compromisation and cord compression with a p-value of 0.0005. Cord hemorrhage observed in 13 (27%), non-hemorrhagic cord contusions in 3 (6.3%), cord transection in 5 (10.4%) and epidural hematoma in 10 (20.8%) patients with an initial high grade of ASIA scale. The visibility score of three-plane mFFE sequence was higher in comparison to the single plane sagittal mFFE and short tau inversion recovery (STIR) sequences. For detection of spinal cord hemorrhage with visibility score of 2, the three-plane mFFE had sensitivity of 77% followed by 38.5% with single plane sagittal mFFE and 7.7% with sagittal STIR images. 26 (54.2%) patients showed neurological improvement in their hospital stay/follow-up period and no improvement observed in 7 (14.6%) patients of acute spinal trauma.

Conclusions

Application of three-plane mFFE sequences detects more spinal cord hemorrhages and vertebral fractures with a better visibility score as compared to the single sagittal plane mFFE and STIR sequence.

Classification of Prostate Transitional Zone Cancer and Hyperplasia Using Deep Transfer Learning From Disease-Related Images

Purpose

The diagnosis of prostate transition zone cancer (PTZC) remains a clinical challenge due to their similarity to benign prostatic hyperplasia (BPH) on MRI. The Deep Convolutional Neural Networks (DCNNs) showed high efficacy in diagnosing PTZC on medical imaging but was limited by the small data size. A transfer learning (TL) method was combined with deep learning to overcome this challenge.

Materials and methods

A retrospective investigation was conducted on 217 patients enrolled from our hospital database (208 patients) and The Cancer Imaging Archive (nine patients). Using T2-weighted images (T2WIs) and apparent diffusion coefficient (ADC) maps, DCNN models were trained and compared between different TL databases (ImageNet vs. disease-related images) and protocols (from scratch, fine-tuning, or transductive transferring).

Results

PTZC and BPH can be classified through traditional DCNN. The efficacy of TL from natural images was limited but improved by transferring knowledge from the disease-related images. Furthermore, transductive TL from disease-related images had comparable efficacy to the fine-tuning method. Limitations include retrospective design and a relatively small sample size.

Conclusion

Deep TL from disease-related images is a powerful tool for an automated PTZC diagnostic system. In developing regions where only conventional MR scans are available, the accurate diagnosis of PTZC can be achieved via transductive deep TL from disease-related images.

Intensity non-uniformity correction in MR imaging using residual cycle generative adversarial network

Correcting or reducing the effects of voxel intensity non-uniformity (INU) within a given tissue type is a crucial issue for quantitative magnetic resonance (MR) image analysis in daily clinical practice. Although having no severe impact on visual diagnosis, the INU can highly degrade the performance of automatic quantitative analysis such as segmentation, registration, feature extraction and radiomics. In this study, we present an advanced deep learning based INU correction algorithm called residual cycle generative adversarial network (res-cycle GAN), which integrates the residual block concept into a cycle-consistent GAN (cycle-GAN). In cycle-GAN, an inverse transformation was implemented between the INU uncorrected and corrected magnetic resonance imaging (MRI) images to constrain the model through forcing the calculation of both an INU corrected MRI and a synthetic corrected MRI. A fully convolution neural network integrating residual blocks was applied in the generator of cycle-GAN to enhance end-to-end raw MRI to INU corrected MRI transformation. A cohort of 55 abdominal patients with T1-weighted MR INU images and their corrections with a clinically established and commonly used method, namely, N4ITK were used as a pair to evaluate the proposed res-cycle GAN based INU correction algorithm. Quantitatively comparisons of normalized mean absolute error (NMAE), peak signal-to-noise ratio (PSNR), normalized cross-correlation (NCC) indices, and spatial non-uniformity (SNU) were made among the proposed method and other approaches. Our res-cycle GAN based method achieved an NMAE of 0.011 ± 0.002, a PSNR of 28.0 ± 1.9 dB, an NCC of 0.970 ± 0.017, and a SNU of 0.298 ± 0.085. Our proposed method has significant improvements (p < 0.05) in NMAE, PSNR, NCC and SNU over other algorithms including conventional GAN and U-net. Once the model is well trained, our approach can automatically generate the corrected MR images in a few minutes, eliminating the need for manual setting of parameters.

False-Negative Initial Magnetic Resonance Imaging in Acute Posterior Circulation Stroke: A Case Report Describing Locked-in Syndrome

Locked-in syndrome is defined as quadriplegia and anarthria with the preservation of consciousness. Typically, locked-in syndrome is caused by an insult to the ventral pons secondary to trauma or vascular disease. Presented herein is a case of a locked-in syndrome with an initial MRI with no restricted diffusion and clinical deterioration over the course of four days. Repeat interval MRI demonstrated bilateral pontine ischemia.

Rapid development of application-specific flexible MRI receive coils

Over the last 30 years, there have been dramatic changes in phased array coil technology leading to increasing channel density and parallel imaging functionality. Current receiver array coils are rigid and often mismatched to patient's size. Recently there has been a move towards flexible coil technology, which is more conformal to the human anatomy. Despite the advances of so-called flexible surface coil arrays, these coils are still relatively rigid and limited in terms of design conformability, compromising signal-to-noise ratio (SNR) for flexibility, and are not designed for optimum parallel imaging performance. The purpose of this study is to report on the development and characterization of a 15-channel flexible foot and ankle coil, rapidly designed and constructed using highly decoupled radio-frequency (RF) coil elements. Coil performance was evaluated by performing SNR and g-factor measurements. In vivo testing was performed in a healthy volunteer using both the 15-channel coil and a commercially available 8-channel foot coil. The highly decoupled elements used in this design allow for extremely rapid development and prototyping of application-specific coils for different patient sizes (adult vs child) with minimal additional design consideration in terms of coil overlap and geometry. Image quality was comparable to a commercially available RF coil.

68Ga-PSMA-11 PET/CT combining ADC value of MRI in the diagnosis of naive prostate cancer: Perspective of radiologist

Ga-PSMA-11 positron emission computed tomography /computed tomography (PET/CT) is more sensitive than magnetic resonance imaging (MRI) in detecting prostate cancer (PCa). We evaluated the value of Ga-PSMA-11 PET/CT with MRI in treatment-naive PCa.This retrospective study was approved by the hospital ethics committee. The MRI and Ga-PSMA-11 PET/CT imaging data of 63 cases of highly suspected PCa were enrolled in this study. The SUVmax and apparent diffusion coefficient (ADC), and their ratio, were assessed as diagnostic markers to distinguish PCa from benign disease.There were 107 prostate lesions detected in 63 cases. Forty cases with 64 malignant primary lesions were confirmed PCa, whereas 23 cases had 43 benign lesions. PSMA-avid lesions correlated with hypointense signal on ADC maps and hyperintense signal on diffusion-weighted imaging. The ADC of PCa was lower than that of benign lesions, and SUVmax and SUVmax/ADC of PCa was higher than that of benign lesions (P < .01). ADC had significant negative correlation with Gleason score (GS) and SUVmax, SUVmax, and SUVmax/ADC positively correlated with GS. From ROC analysis, we established cutoff values of ADC, SUVmax, and SUVmax/ADC at 1.02 × 10mm/s, 11.72, and 12.35, respectively, to differentiate PCa from benign lesions. The sensitivity, specificity, and AUC were 90.6%, 58.1%, and 0.816 for ADC, 67.2%, 97.7%, and 0.905 for SUVmax, and 81.2%, 88.4%, and 0.929 for SUVmax/ADC, respectively.Ga-PSMA-11 PET/CT combined with MRI offers higher diagnostic efficacy in the detection of PCa than either modality alone.

Multi-Contrast Super-Resolution MRI Through a Progressive Network

Magnetic resonance imaging (MRI) is widely used for screening, diagnosis, image-guided therapy, and scientific research. A significant advantage of MRI over other imaging modalities such as computed tomography (CT) and nuclear imaging is that it clearly shows soft tissues in multi-contrasts. Compared with other medical image super-resolution methods that are in a single contrast, multi-contrast super-resolution studies can synergize multiple contrast images to achieve better super-resolution results. In this paper, we propose a one-level non-progressive neural network for low up-sampling multi-contrast super-resolution and a two-level progressive network for high up-sampling multi-contrast super-resolution. The proposed networks integrate multi-contrast information in a high-level feature space and optimize the imaging performance by minimizing a composite loss function, which includes mean-squared-error, adversarial loss, perceptual loss, and textural loss. Our experimental results demonstrate that 1) the proposed networks can produce MRI super-resolution images with good image quality and outperform other multi-contrast super-resolution methods in terms of structural similarity and peak signal-to-noise ratio; 2) combining multi-contrast information in a high-level feature space leads to a significantly improved result than a combination in the low-level pixel space; and 3) the progressive network produces a better super-resolution image quality than the non-progressive network, even if the original low-resolution images were highly down-sampled.

Tumoral Calcinosis Presentation in Operated Developmental Dysplasia of the Hip: A Case Report and Review of Literature

Tumoral calcinosis has long been a disputed clinical-pathological subject. It has been characterized by the deposition of calcium salt and hydroxyapatite in different periarticular soft tissue regions. It is most commonly seen in adults, and rarely seen in children. In this report, we present the case of a six-year-old girl referred to our institution for one year with a history of left hip pain and swelling. The patient underwent an open reduction of left hip and acetabuloplasty for developmental dysplasia of the hip (DDH) at the age of two years. Systematic investigations were performed and showed that the patient had abnormal calcifications and large, ill-defined lesions with an irregular margin on the left hip extended to the left gluteal area with skin ulceration suggestive of primary tumor calcinosis. Medical therapy has started, and a follow-up appointment was given to her in a pediatric metabolic clinic. In addition, we present a brief literature review of the effect of medical and surgical treatments on tumor calcinosis.

Magnetic Resonance Imaging Findings and Their Association with Electroencephalogram Data in Children with Partial Epilepsy

Background

It is important to identify the neuroimaging features that are associated with partial epilepsy in children. Advances in technology have recently been made to localize focal epileptogenic lesions, especially high-resolution structural imaging with magnetic resonance imaging (MRI). The recommendation that electroencephalography (EEG) should be the gold standard and that MRI should be optional has been questioned. The present study aims to evaluate the efficacy of MRI in children with partial epilepsy and to compare the diagnostic yields of MRI and EEG data.

Methods

The present study was conducted among one hundred twelve 1- to 6-year-old children with partial epilepsy. All patients underwent EEG and brain MRI. The epileptogenic lesions were identified on the basis of the signal intensities and morphological abnormalities seen on MRI. The correlation between MRI and EEG abnormal findings was analyzed using a chi-square test.

Results

Abnormal MRI findings were present in 34.8% (n = 39) of the sample. The EEG and MRI data agreed with respect to classifications into abnormal or normal in 48.2% of the sample (n = 54). Of the 27 patients with normal EEG findings, six (22.2%) had abnormal MRI findings. Inter-rater agreement showed the compatibility between EEG and MRI not significant (weighted Kappa = 0.105).

Conclusion

A number of MRI abnormalities were found in our study of otherwise normal children, although the correlation between these results was not clear. The follow-up of these children will help us identify the important abnormalities. Despite the small sample size, our results showed that normal EEG findings do not predict normal brain MRI data in children with partial epilepsy.

Obtaining Imaging Cost and Quality Information in Femoroacetabular Impingement: The Patient Experience

BACKGROUND

Recent changes in healthcare have placed increased emphasis on price transparency, quality measures, and improving the patient experience. However, limited information is available for patient cost of obtaining a hip MRI and factors associated with cost variability. For a patient with femoroacetabular impingement (FAI), this study sought to report (1) the availability of pricing and quality information for a hip magnetic resonance imaging (MRI) in the state of Iowa, (2) the time investment required to obtain pricing and quality information, and (3) factors that influence hip MRI cost, quality and the time investment required for patients to obtain cost and quality information.

METHODS

Within the state of Iowa, 126 unique hospital institutions and 30 active, private orthopaedic practices were identified. All 156 providers were contacted via telephone using a standardized script of a hypothetical 25-year-old adult male patient with FAI requesting a quote for a hip MRI. Cost of the MRI and its components, availability of payment discounts, and MRI magnet tesla (T) were requested. A final bundled cost (FBC) was calculated for each MRI provider with all available services and discounts applied. The total amount of time needed to obtain a quote from each location was recorded.

RESULTS

One hundred and thirty-six of the 156 institutions contacted provided hip MRI services (87%). Median call duration was 9.1 minutes (Range 2.3-25.6). Median FBC was $2,114.00 (Range $484.75-4,463.00) across all providers. Hospital median FBC was $2,261.70 (Range $909.62-4,463.00) versus $1,225.13 (Range $484.75-2,218.40) for independent imaging centers (P<0.0001). No difference in median cost was observed between nine available 3.0 T machines and eighty-nine 1.5 T machines (P=0.2655).

CONCLUSIONS

MRI cost varies widely across the state of Iowa and within individual metropolitan areas. Hip MRIs cost less at independent imaging centers compared to hospital locations. The amount of time required to obtain quality and cost data for a hip MRI presents a substantial time burden for patients with FAI. Surgeons, healthcare systems, and policy makers should be cognizant of the large price differences for a hip MRI and the time burden placed on patients with FAI to obtain this information.Level of Evidence: IV.

Establishment and Evaluation of a Monkey Acute Cerebral Ischemia Model

OBJECTIVES

Cerebral ischemia seriously threatens human health and is characterized by high rates of incidence, disability and death. Developing an ideal animal model of cerebral ischemia that reflects the human clinical features is critical for pathological studies and clinical research. The goal of this study is to establish a local cerebral ischemia model in rhesus macaque, thereby providing an optimal animal model to study cerebral ischemia.

METHODS

Eight healthy rhesus monkeys were selected for this study. CT scans were performed before the operation to exclude cerebral vascular and intracranial lesions. Under guidance and monitoring with digital subtraction angiography (DSA), a microcatheter was inserted into the M1 segment of the middle cerebral artery (MCA) via the femoral artery. Then, autologous white thrombi were introduced to block blood flow. Immediately following embolization, multisequence MRI was used to monitor cerebrovascular and brain parenchymal conditions. Twenty-four hours after embolization, 2 monkeys were sacrificed and subjected to perfusion, fixation and pathological examination.

RESULTS

The cerebral ischemia model was established in 7 rhesus monkeys; one animal died during intubation. DSA and magnetic resonance angiography (MRA) indicated the presence of an arterial occlusion. MRI showed acute local cerebral ischemia. HE staining revealed infarct lesions formed in the brain tissues, and thrombi were present in the cerebral artery.

CONCLUSION

We established a rhesus macaque model of local cerebral ischemia by autologous thrombus placement. This model has important implications for basic and clinical research on cerebral ischemia. MRI and DSA can evaluate the models to ensure accuracy and effectiveness.

Standardized Assessment of Automatic Segmentation of White Matter Hyperintensities and Results of the WMH Segmentation Challenge

Quantification of cerebral white matter hyperintensities (WMH) of presumed vascular origin is of key importance in many neurological research studies. Currently, measurements are often still obtained from manual segmentations on brain MR images, which is a laborious procedure. The automatic WMH segmentation methods exist, but a standardized comparison of the performance of such methods is lacking. We organized a scientific challenge, in which developers could evaluate their methods on a standardized multi-center/-scanner image dataset, giving an objective comparison: the WMH Segmentation Challenge. Sixty T1 + FLAIR images from three MR scanners were released with the manual WMH segmentations for training. A test set of 110 images from five MR scanners was used for evaluation. The segmentation methods had to be containerized and submitted to the challenge organizers. Five evaluation metrics were used to rank the methods: 1) Dice similarity coefficient; 2) modified Hausdorff distance (95th percentile); 3) absolute log-transformed volume difference; 4) sensitivity for detecting individual lesions; and 5) F1-score for individual lesions. In addition, the methods were ranked on their inter-scanner robustness; 20 participants submitted their methods for evaluation. This paper provides a detailed analysis of the results. In brief, there is a cluster of four methods that rank significantly better than the other methods, with one clear winner. The inter-scanner robustness ranking shows that not all the methods generalize to unseen scanners. The challenge remains open for future submissions and provides a public platform for method evaluation.

Spongiform leucoencephalomyelopathy in border terriers: clinical, electrophysiological and imaging features

A novel spongiform leucoencephalomyelopathy was reported in border terrier puppies in 2012 causing a shaking puppy phenotype, but no information regarding clinical progression, imaging or electrophysiological findings were available. The aim of the present study was to describe the clinical, electrophysiological and MRI features of this disease in seven dogs and compare them with human white matter disorders. All cases presented with cerebellar ataxia and severe generalised coarse body tremors, which started at three weeks of age. The three cases that were not euthanased showed slow but progressive improvement over several months. Brainstem auditory evoked response demonstrated a normal wave I, reduced amplitude of wave II and an absence of waves III-VII. MRI revealed bilateral and symmetrical T2-weighted hyperintensities affecting the brainstem and cerebellar white matter. Histological examination of the brain and spinal cord showed spongiform change affecting the white matter of the cerebellum, brainstem and spinal cord with decreased myelin content. In summary, this leucoencephalomyelopathy has a pathognomonic clinical presentation with defining MRI and electrophysiological characteristics, and it is the first report to describe a long-term improvement of this condition.

Advance Rectal Cancer in a Young Patient: Should Screening Start Early?

Colorectal cancer is the third most common non-cutaneous malignancy in the United States, and the second most common cause of cancer-related deaths. Colorectal cancer is a broad term to include both colon and rectal cancer. Rectal cancer is commonly seen in age more the 50 years and often present with rectal bleeding. In this article, we will be discussing about a young female patient who presented with somatic pain as an initial symptom for metastatic rectal adenocarcinoma.

Linear magnetic resonance imaging measurements of the hippocampal formation differ in young versus old dogs

Age-related hippocampal formation (HF) atrophy has been documented on MRI studies using volumetric analysis and visual rating scales. This retrospective cross-sectional study aimed to compare linear MRI measurements of the HF between young (1–3 years) and old (>10 years) non-brachycephalic dogs, with normal brain anatomy and cerebrospinal fluid (CSF) analysis. Right and left hippocampal formation height (HFH), height of the brain (HB) and mean HFH/HB ratio were measured by two observers on a transverse T2 fluid-attenuated inversion recovery sequence containing rostral colliculi and mesencephalic aqueduct.119 MRI studies were enrolled: 75 young and 44 old dogs. Left and right HFH were greater (p<0.0001) in young, while HB was greater in old dogs (p=0.024). Mean HFH/HB ratio was 15.66 per cent and 18.30 per cent in old and young dogs (p<0.0001). No differences were found comparing measurements between epileptic and non-epileptic dogs. Old dogs have a greater HB; this may represent the different study populations or a statistical phenomenon. Ageing affects HF linear measurements. A reduction of mean HFH/HB ratio between 18.30 per cent and 15.66 per cent should be considered a physiological age-related process of the canine lifespan. The use of mean HFH/HB ratio could be considered for quantifying brain atrophy in elderly dogs.

Evaluation of the Geometric and Dosimetric Accuracy of Synthetic Computed Tomography Images for Magnetic Resonance Imaging-only Stereotactic Radiosurgery

Introduction

Stereotactic radiosurgery (SRS) plans created using synthetic computed tomography (CT) images derived from magnetic resonance imaging (MRI) data may offer the advantage of inhomogeneity correction by convolution algorithms, as is done for CT-based plans. We sought to determine and validate the clinical significance and accuracy of synthetic CT images for inhomogeneity correction in MRI-only stereotactic radiosurgery plans for treatment of brain tumors.

Methods

In this retrospective study, data from two patients with brain metastases and one with meningioma who underwent imaging with multiple modalities and received frameless SRS treatment were analyzed. The SRS plans were generated using a convolution algorithm to account for brain inhomogeneity using CT and synthetic CT images and compared with the original clinical TMR10 plans created using MRI images.

Results

Synthetic CT-derived SRS plans are comparable with CT-based plans using convolution algorithm, and for some targets, based on location, they provided better coverage and a lower maximum dose.

Conclusions

The results suggest similar dose delivery results for CT and synthetic CT-based treatment plans. Synthetic CT plans offered a noticeable improvement in target dose coverage and a more gradual dose fall-off relative to TMR10 MRI-based plans. The major disadvantage is a slightly increased dose (by 0.37%) to nearby healthy tissue (brainstem) for synthetic CT-based plans relative to those created using clinical MRI images, which may be a problem for patients undergoing high-dose treatment.

A Novel Expandable Catheter Wireless Amplified NMR Detector for MR Sensitivity Accessing the Kidney in Rodent Model

This paper demonstrates the enlarged effective range for MRI sensitivity enhancement with a deformable catheter MRI coils integrated with a wirelessly powered amplifier. The expandable balloon wireless amplified nuclear magnetic resonance detector (WAND) is constructed on a copper-clad polyimide film to resonate at the first and second harmonics of the proton Larmor frequency at 7 Tesla. The WAND is then mounted on a balloon catheter system for easy delivery inside confined orifice. Upon reaching the region of interest, it is unfolded out of the sheath tube to increase its effective size. Magnetic resonance (MR) imaging experiments with and without the WAND are performed both in a water phantom and in a live rat to evaluate the WAND's sensitivity advantage. Expanded from a 3 mm diameter in its folded state, this deformable WAND can change its width by >100% in its inflated state to at least 6 mm, leading to a sensitive detection region extending to up to 20 mm in the transverse direction. When the deformable WAND is placed in an artery in the region of the kidney of a live rat, it could achieve at least a 10-fold SNR gain over images acquired by a standard external detector of 22 mm diameter, even though the region of interest is separated from the WAND's surface by a distance larger than the WAND's own width. The proposed expandable catheter WAND could significantly enlarge the effective range for MR sensitivity enhancement in-vivo, enabling versatile applications in interventional MRI.

Association Between Early Life Weight Gain and Abdominal Fat Partitioning at 4.5 Years is Sex, Ethnicity, and Age Dependent

OBJECTIVE

The aim of this study was to investigate the independent associations between age-specific annual weight gain from birth to age 4 years and fat deposition in metabolically distinct compartments at age 4.5 years in a South Asian longitudinal birth cohort.

METHODS

Volumetric abdominal magnetic resonance imaging with comprehensive segmentation of deep and superficial subcutaneous adipose tissue (SAT) and visceral adipose tissues (VAT) was performed in 316 children (150 boys and 166 girls in three ethnic groups; 158 Chinese, 94 Malay, and 64 Indian) aged 4.5 years. Associations between fat volumes and annual relative weight gain conditional on past growth were assessed overall and stratified by sex and ethnicity.

RESULTS

Conditional relative weight gain had stronger associations with greater SAT and VAT at age 4.5 years in girls than boys and in Indians compared with Malay and Chinese. Overall, the magnitude of association was the largest during 2 to 3 years for SAT and 1 to 2 years for VAT. Despite similar body weight, Indian children and girls had the highest deep and superficial SAT volumes at age 4.5 years (all interactions P < 0.05). No significant sex or ethnic differences were observed in VAT. With increasing BMI, Indian children had the highest tendency to accumulate VAT, and girls accumulated more fat than boys in all depots (all interactions P < 0.001).

CONCLUSIONS

Indian ethnicity and female sex predisposed children to accumulate more fat in the VAT depot with increasing conditional relative weight gain in the second year of life. Thus, 1 to 2 years of age may be a critical window for interventions to reduce visceral fat accumulation.

CONtrast Conformed Electrical Properties Tomography (CONCEPT) Based on Multi- Channel Transmission and Alternating Direction Method of Multipliers

In magnetic resonance-based electrical properties tomography (EPT), circularly polarized magnetic field B1 from a transmit radiofrequency (RF) coil is measured and utilized to infer the electrical conductivity and permittivity of biological tissues. Compared with a quadrature RF coil, a multi-channel transmit coil provides a plurality of unique transmit B1 patterns that help to alleviate the under-determinedness of EPT reconstruction problem, and it also allows to circumvent the "transceive phase assumption" that fails at ultra-high-field MRI. Here, a new approach, contrast conformed electrical properties tomography or CONCEPT, is proposed based on the multi-channel transmission that retrieves electrical properties (EPs) by solving a linear partial differential equation with discriminated L1 and L2 norm regularization informed by intermediate EP gradient. The theory of CONCEPT and a fast reconstruction algorithm based on the alternating direction method of multipliers are described and evaluated using numerical simulations, phantom experiment, and analysis of in vivo human brain data at 7 T MRI. Compared with the multi-channel gradient-based EPT (gEPT) method, this new technology does not require receive- B1 sensitivity profiles and does not rely on symmetry assumption regarding RF coil design and imaged target. Moreover, it is not dependent on external prior information, such as integration seed point or anatomical MRI, which can be sources of bias in reconstructed EP values. By deriving EPs from transmit B1 profiles only, CONCEPT can be used with RF coils that include receive-only arrays with large channel count which can, in turn, offer substantial gains in signal-to-noise ratio. It also holds potentials to image unsymmetrical body organs and diseased brain. CONCEPT provides solutions for the practical problems during the implementation of gEPT, thus representing a more generalized framework in the context of multi-channel RF transmission.

Longitudinally Guided Super-Resolution of Neonatal Brain Magnetic Resonance Images

Neonatal magnetic resonance (MR) images typically have low spatial resolution and insufficient tissue contrast. Interpolation methods are commonly used to upsample the images for the subsequent analysis. However, the resulting images are often blurry and susceptible to partial volume effects. In this paper, we propose a novel longitudinally guided super-resolution (SR) algorithm for neonatal images. This is motivated by the fact that anatomical structures evolve slowly and smoothly as the brain develops after birth. We propose a strategy involving longitudinal regularization, similar to bilateral filtering, in combination with low-rank and total variation constraints to solve the ill-posed inverse problem associated with image SR. Experimental results on neonatal MR images demonstrate that the proposed algorithm recovers clear structural details and outperforms state-of-the-art methods both qualitatively and quantitatively.