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1.
Bone Joint J ; 103-B(4): 725-733, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33789478

RESUMEN

AIMS: The aim of this study was to determine the differences in spinal imaging characteristics between subjects with or without lumbar developmental spinal stenosis (DSS) in a population-based cohort. METHODS: This was a radiological analysis of 2,387 participants who underwent L1-S1 MRI. Means and ranges were calculated for age, sex, BMI, and MRI measurements. Anteroposterior (AP) vertebral canal diameters were used to differentiate those with DSS from controls. Other imaging parameters included vertebral body dimensions, spinal canal dimensions, disc degeneration scores, and facet joint orientation. Mann-Whitney U and chi-squared tests were conducted to search for measurement differences between those with DSS and controls. In order to identify possible associations between DSS and MRI parameters, those who were statistically significant in the univariate binary logistic regression were included in a multivariate stepwise logistic regression after adjusting for demographics. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported where appropriate. RESULTS: Axial AP vertebral canal diameter (p < 0.001), interpedicular distance (p < 0.001), AP dural sac diameter (p < 0.001), lamina angle (p < 0.001), and sagittal mid-vertebral body height (p < 0.001) were significantly different between those identified as having DSS and controls. Narrower interpedicular distance (OR 0.745 (95% CI 0.618 to 0.900); p = 0.002) and AP dural sac diameter (OR 0.506 (95% CI 0.400 to 0.641); p < 0.001) were associated with DSS. Lamina angle (OR 1.127 (95% CI 1.045 to 1.214); p = 0.002) and right facet joint angulation (OR 0.022 (95% CI 0.002 to 0.247); p = 0.002) were also associated with DSS. No association was observed between disc parameters and DSS. CONCLUSION: From this large-scale cohort, the canal size is found to be independent of body stature. Other than spinal canal dimensions, abnormal orientations of lamina angle and facet joint angulation may also be a result of developmental variations, leading to increased likelihood of DSS. Other skeletal parameters are spared. There was no relationship between DSS and soft tissue changes of the spinal column, which suggests that DSS is a unique result of bony maldevelopment. These findings require validation in other ethnicities and populations. Level of Evidence: I (diagnostic study) Cite this article: Bone Joint J 2021;103-B(4):725-733.


Asunto(s)
Degeneración del Disco Intervertebral/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Conducto Vertebral/diagnóstico por imagen , Estenosis Espinal/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
2.
Anticancer Res ; 41(4): 2183-2186, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33813431

RESUMEN

BACKGROUND/AIM: The aim of this study was to identify simple and reliable factors to detect clinically insignificant prostate cancer (PC) for avoiding immediate prostate biopsies using biparametric magnetic resonance imaging (MRI), which consists of T2-weighted and diffusion-weighted imaging. PATIENTS AND METHODS: We retrospectively evaluated 427 men with suspected PC, who underwent biparametric MRI and standard 12-core transrectal prostate biopsy. MRI and prostate specific antigen density (PSAD) were analysed. To evaluate the combination of the two parameters, patients were divided into three groups (Group A: MRI negative and PSAD <0.23, Group B: MRI positive or PSAD ≥0.23, Group C: MRI positive and PSAD ≥0.23). A grade of ≥2 was defined as clinically significant PC. RESULTS: Clinically significant PC was detected in 46.5% of men with positive MRI findings, and 60.0% of men with PSAD ≥0.23. When combining MRI and PSAD, detection rates of clinically significant PC were 10.0%, 28.4% and 65.3% in group A, B and, C, respectively. CONCLUSION: Negative biparametric MRI findings with PSAD <0.23 might be a reliable evidence for avoiding immediate prostate biopsies.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Antígeno Prostático Específico/análisis , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja Gruesa/métodos , Imagen de Difusión por Resonancia Magnética , Humanos , Biopsia Guiada por Imagen , Pruebas Inmunológicas , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Cuidados Preoperatorios , Próstata/patología , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/metabolismo , Estudios Retrospectivos , Carga Tumoral , Ultrasonografía Intervencional
3.
Nat Commun ; 12(1): 1795, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741933

RESUMEN

Neural computations are often fast and anatomically localized. Yet, investigating such computations in humans is challenging because non-invasive methods have either high temporal or spatial resolution, but not both. Of particular relevance, fast neural replay is known to occur throughout the brain in a coordinated fashion about which little is known. We develop a multivariate analysis method for functional magnetic resonance imaging that makes it possible to study sequentially activated neural patterns separated by less than 100 ms with precise spatial resolution. Human participants viewed five images individually and sequentially with speeds up to 32 ms between items. Probabilistic pattern classifiers were trained on activation patterns in visual and ventrotemporal cortex during individual image trials. Applied to sequence trials, probabilistic classifier time courses allow the detection of neural representations and their order. Order detection remains possible at speeds up to 32 ms between items (plus 100 ms per item). The frequency spectrum of the sequentiality metric distinguishes between sub- versus supra-second sequences. Importantly, applied to resting-state data our method reveals fast replay of task-related stimuli in visual cortex. This indicates that non-hippocampal replay occurs even after tasks without memory requirements and shows that our method can be used to detect such spontaneously occurring replay.


Asunto(s)
Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Imagen por Resonancia Magnética/métodos , Memoria/fisiología , Corteza Visual/diagnóstico por imagen , Corteza Visual/fisiología , Adulto , Algoritmos , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Modelos Neurológicos , Análisis Multivariante , Tiempo de Reacción/fisiología , Adulto Joven
4.
Nat Commun ; 12(1): 1793, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741956

RESUMEN

Neural substrates of "mind wandering" have been widely reported, yet experiments have varied in their contexts and their definitions of this psychological phenomenon, limiting generalizability. We aimed to develop and test the generalizability, specificity, and clinical relevance of a functional brain network-based marker for a well-defined feature of mind wandering-stimulus-independent, task-unrelated thought (SITUT). Combining functional MRI (fMRI) with online experience sampling in healthy adults, we defined a connectome-wide model of inter-regional coupling-dominated by default-frontoparietal control subnetwork interactions-that predicted trial-by-trial SITUT fluctuations within novel individuals. Model predictions generalized in an independent sample of adults with attention-deficit/hyperactivity disorder (ADHD). In three additional resting-state fMRI studies (total n = 1115), including healthy individuals and individuals with ADHD, we demonstrated further prediction of SITUT (at modest effect sizes) defined using multiple trait-level and in-scanner measures. Our findings suggest that SITUT is represented within a common pattern of brain network interactions across time scales and contexts.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Conectoma/métodos , Imagen por Resonancia Magnética/métodos , Red Nerviosa/diagnóstico por imagen , Adolescente , Adulto , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Encéfalo/fisiología , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiología , Pruebas Neuropsicológicas , Descanso/fisiología , Adulto Joven
5.
Medicine (Baltimore) ; 100(12): e25266, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33761727

RESUMEN

INTRODUCTION: The objective is to analyze the clinical diagnosis and treatment of children with rescindable posterior encephalopathy syndrome (PRES) and intracranial hemorrhage (ICH) to improve the pediatrician's understanding of PRES combined with ICH in children. PATIENT CONCERNS AND DIAGNOSIS: After liver transplantation, the patient developed symptoms of epilepsy and coma. Meanwhile, massive necrosis of acute cerebral infarction and small hemorrhage was observed in the left cerebellar hemisphere and left occipital lobe, respectively. The above symptoms were initially diagnosed as PRES. INTERVENTIONS AND OUTCOMES: After adjusting the anti-rejection drug regimen, it was found that the child's neurological symptoms were relieved, and the limb motor function gradually recovered during follow-up. Imaging examination showed significant improvement on abnormal signals in brain. CONCLUSION: In general, children with PRES may further develop ICH and contribute to a poor prognosis. Early diagnosis, detection of risk factors and timely adjustment of medication regimen are the keys to prevent irreversible brain damage.


Asunto(s)
Conductos Biliares/anomalías , Atresia Biliar/cirugía , Infarto Cerebral , Inmunosupresión , Hemorragias Intracraneales , Síndrome de Leucoencefalopatía Posterior , Ajuste de Riesgo/métodos , Atresia Biliar/diagnóstico , Atresia Biliar/etiología , Encéfalo/diagnóstico por imagen , Daño Encefálico Crónico/etiología , Daño Encefálico Crónico/prevención & control , Infarto Cerebral/diagnóstico , Infarto Cerebral/etiología , Preescolar , Diagnóstico Precoz , Humanos , Inmunosupresión/efectos adversos , Inmunosupresión/métodos , Hemorragias Intracraneales/diagnóstico , Hemorragias Intracraneales/etiología , Trasplante de Hígado/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Síndrome de Leucoencefalopatía Posterior/diagnóstico , Síndrome de Leucoencefalopatía Posterior/etiología , Síndrome de Leucoencefalopatía Posterior/fisiopatología , Síndrome de Leucoencefalopatía Posterior/terapia , Tomografía Computarizada por Rayos X/métodos
6.
BMJ Case Rep ; 14(3)2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33762283

RESUMEN

COVID-19 has now emerged from a respiratory illness to a systemic viral illness with multisystem involvement. There is still a lot to learn about this illness as new disease associations with COVID-19 emerge consistently. We present a unique case of a neurological manifestation of a patient with structural brain disease who was COVID-19 positive and developed mental status changes, new-onset seizures and findings suggestive of viral meningitis on lumbar puncture. We also review the literature and discuss our case in the context of the other cases reported. We highlight the value of considering seizures and encephalopathy as one of the presenting features of COVID-19 disease.


Asunto(s)
Encefalopatías/etiología , Convulsiones/etiología , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/uso terapéutico , Adulto , Alanina/análogos & derivados , Alanina/uso terapéutico , Anticonvulsivantes/uso terapéutico , Antivirales/uso terapéutico , Encefalopatías/diagnóstico , Encefalopatías/terapia , /terapia , Confusión/complicaciones , Humanos , Inmunización Pasiva/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Reacción en Cadena de la Polimerasa , Radiografía/métodos , Convulsiones/terapia , Resultado del Tratamiento
7.
J Comput Assist Tomogr ; 45(2): 277-284, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33661152

RESUMEN

PURPOSE: The aims of this study were to evaluate the relationship between age change and amide proton transfer (APT) signal in each region of the whole brain and to derive the standard value of APT signal in each brain region of normal adults. MATERIALS AND METHODS: Using the mDIXON 3-dimensional-APT sequence of the fast spin echo method, an APT image was obtained. In total, 60 patients (mean age, 49.8 ± 16.9 years) with no abnormal findings on magnetic resonance imaging data were included. For image analysis, registration parameters were created using the FMRIB Software Library 5.0.11, and then a region of interest was set in the Montreal Neurological Institute structural atlas for analysis. Statistical analyses were performed using the age-dependent and sex differences in APT signals from each brain region. RESULTS: No significant correlation was seen between APT signal and age and sex in all brain regions. CONCLUSION: Under the APT imaging parameter conditions used in this study, local brain APT signals in healthy adults are independent of age and sex.


Asunto(s)
Química Encefálica/fisiología , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Proteínas del Tejido Nervioso/análisis , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas del Tejido Nervioso/química , Factores Sexuales , Adulto Joven
8.
Medicine (Baltimore) ; 100(9): e24687, 2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33655933

RESUMEN

RATIONALE: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid deposition disorder characterized by systemic signs and neurological dysfunction. The radiological features of CTX are infrequently summarized in the literature. PATIENT CONCERNS: We described a 40-year-old male patient who repeatedly engaged in wrestling matches and presented with progressive difficulty in walking and reduced balance with egg-sized, hard, smooth, and painless masses in both ankles. DIAGNOSIS: Neuroimaging examination showed abnormalities both supra- and infratentorially. Bilateral ankle joint magnetic resonance imaging showed bilateral xanthomata of the Achilles tendon. The diagnosis was confirmed by the detection of a sterol 27-hydroxylase gene mutation. INTERVENTIONS: The patient was treated with chenodeoxycholic acid (250 mg 3 times per day). OUTCOMES: To date, the patient's bilateral xanthomas of the Achilles tendon have begun to diminish, and his neurological impairment has not deteriorated further but has not yet improved. LESSONS: We report a rare case of CTX and summarize the clinical and imaging features of this disease. Our findings suggest that the abnormal signals in the dentate nucleus or a long spinal cord lesion involving the central and posterior cord, combined with tendon xanthoma, are important clues for the diagnosis of CTX.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Enfermedades del Sistema Nervioso/congénito , Xantomatosis Cerebrotendinosa/complicaciones , Tendón Calcáneo/diagnóstico por imagen , Tendón Calcáneo/patología , Adulto , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/patología , Ácido Quenodesoxicólico/uso terapéutico , Humanos , Masculino , Enfermedades del Sistema Nervioso/diagnóstico por imagen , Enfermedades del Sistema Nervioso/patología , Xantomatosis Cerebrotendinosa/diagnóstico por imagen , Xantomatosis Cerebrotendinosa/patología
9.
Medicine (Baltimore) ; 100(9): e24972, 2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33655964

RESUMEN

INTRODUCTION: Vaginal agenesis is a congenital disorder, which can be managed by nonsurgical dilation or surgical reconstruction of the vagina. The sigmoid vaginoplasty procedure is a popular approach, which pulls down part of the sigmoid colon to form a neovagina. One complication of this procedure is introital stenosis. PATIENT CONCERNS: A 55-year-old woman presented to the outpatient general surgery department with severe, persistent abdominal pain. The patient was diagnosed with congenital absence of uterus and vagina, and a sigmoid vaginoplasty was performed 34 years ago. DIAGNOSIS: A pelvic MRI and an abdominal enhanced CT scan were performed, finding that the uterus was absent, and the os of the vagina was closed, forming a closed loop full of fluid. Introital atresia and closed loop of neovaginal colon conduit were diagnosed. INTERVENTIONS: Based on our conclusions and the patient's consent we surgically removed the neovagina. OUTCOMES: After surgery, the abdominal pain was relieved, and the patient reported full recovery during a 6-month follow-up appointment. CONCLUSION: Introital stenosis is one of the long-term complications of sigmoid vaginoplasty procedure. Introital stenosis, leading to introital atresia, is rare but may occur. Surgical removal of neovagina can relieve the pain in patients who do not have the demand of sexual intercourse.


Asunto(s)
Colon Sigmoide/cirugía , Anomalías Congénitas/cirugía , Procedimientos Quirúrgicos Ginecológicos/métodos , Procedimientos Quirúrgicos Reconstructivos/métodos , Estructuras Creadas Quirúrgicamente , Vagina/anomalías , Anomalías Congénitas/diagnóstico , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Persona de Mediana Edad , Vagina/cirugía
10.
Eur J Endocrinol ; 184(4): 565-574, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33730688

RESUMEN

Design: Cushing's disease (CD) is a rare clinical syndrome characterized by chronic exposure to hypercortisolism due to an adrenocorticotropic hormone-secreting pituitary adenoma. The adverse effects of chronic exposure to hypercortisolism on the human brain remain unclear. The purpose of this study was to assess the prevalence of cerebral microbleeds (CMBs) in CD patients and their associations with clinical characteristics. Methods: In this study, 48 active CD patients, 39 remitted CD patients, and 52 healthy control (HC) subjects underwent MRI. CD patients also underwent neuropsychological testing and clinical examinations. The number, locations, and volumes of CMBs were assessed on quantitative susceptibility mapping (QSM) images and with the Microbleed Anatomical Rating Scale. The correlation between CMBs and clinical characteristics was explored. Results: The prevalence of CMBs among active and remitted CD patients was higher than that among HCs (16.3%, 20.5%, and 3.3%, respectively). Moreover, the age of CD patients with CMBs were much younger than HCs with CMBs. Furthermore, the increased number of CMBs in active CD patients was associated with increased cerebrospinal fluid (CSF) volumes in remitted CD patients. Conclusions: Chronic exposure to hypercortisolism may be relevant to CMBs and significantly correlated with altered brain volumes in CD.


Asunto(s)
Encéfalo/diagnóstico por imagen , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/etiología , Imagen por Resonancia Magnética/métodos , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/complicaciones , Adulto , Anciano , Encéfalo/patología , Mapeo Encefálico/métodos , Estudios de Casos y Controles , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/patología , Estudios Transversales , Síndrome de Cushing/complicaciones , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/epidemiología , Síndrome de Cushing/patología , Susceptibilidad a Enfermedades/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/diagnóstico , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/epidemiología , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/patología , Prevalencia
11.
Nat Biomed Eng ; 5(3): 252-263, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33686281

RESUMEN

Contrast agents for magnetic resonance imaging (MRI) improve anatomical visualizations. However, owing to poor image resolution in whole-body MRI, resolving fine structures is challenging. Here, we report that a nanoparticle with a polysaccharide supramolecular core and a shell of amorphous-like hydrous ferric oxide generating strong T1 MRI contrast (with a relaxivity coefficient ratio of ~1.2) facilitates the imaging, at resolutions of the order of a few hundred micrometres, of cerebral, coronary and peripheral microvessels in rodents and of lower-extremity vessels in rabbits. The nanoparticle can be synthesized at room temperature in aqueous solution and in the absence of surfactants, has blood circulation and renal clearance profiles that prevent opsonization, and leads to better imaging performance than Dotarem (gadoterate meglumine), a clinically approved gadolinium-based MRI contrast agent. The nanoparticle's biocompatibility and imaging performance may prove advantageous in a broad range of preclinical and clinical applications of MRI.


Asunto(s)
Dextranos/química , Compuestos Férricos/química , Imagen por Resonancia Magnética/métodos , Nanopartículas/química , Animales , Materiales Biocompatibles/química , Medios de Contraste/química , Gadolinio/química , Meglumina/química , Ratones , Ratones Endogámicos BALB C , Microvasos/patología , Compuestos Organometálicos/química , Tamaño de la Partícula , Polisacáridos/química , Conejos , Ratas , Ratas Sprague-Dawley
12.
Nat Commun ; 12(1): 1922, 2021 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-33771999

RESUMEN

Despite major advances in measuring human brain activity during and after educational experiences, it is unclear how learners internalize new content, especially in real-life and online settings. In this work, we introduce a neural approach to predicting and assessing learning outcomes in a real-life setting. Our approach hinges on the idea that successful learning involves forming the right set of neural representations, which are captured in canonical activity patterns shared across individuals. Specifically, we hypothesized that learning is mirrored in neural alignment: the degree to which an individual learner's neural representations match those of experts, as well as those of other learners. We tested this hypothesis in a longitudinal functional MRI study that regularly scanned college students enrolled in an introduction to computer science course. We additionally scanned graduate student experts in computer science. We show that alignment among students successfully predicts overall performance in a final exam. Furthermore, within individual students, we find better learning outcomes for concepts that evoke better alignment with experts and with other students, revealing neural patterns associated with specific learned concepts in individuals.


Asunto(s)
Corteza Cerebral/diagnóstico por imagen , Aprendizaje , Imagen por Resonancia Magnética/métodos , Programas Informáticos , Estudiantes/estadística & datos numéricos , Curriculum , Evaluación Educacional/métodos , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Factores de Tiempo , Universidades , Adulto Joven
13.
Nat Commun ; 12(1): 1851, 2021 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-33767170

RESUMEN

Radiographic imaging is routinely used to evaluate treatment response in solid tumors. Current imaging response metrics do not reliably predict the underlying biological response. Here, we present a multi-task deep learning approach that allows simultaneous tumor segmentation and response prediction. We design two Siamese subnetworks that are joined at multiple layers, which enables integration of multi-scale feature representations and in-depth comparison of pre-treatment and post-treatment images. The network is trained using 2568 magnetic resonance imaging scans of 321 rectal cancer patients for predicting pathologic complete response after neoadjuvant chemoradiotherapy. In multi-institution validation, the imaging-based model achieves AUC of 0.95 (95% confidence interval: 0.91-0.98) and 0.92 (0.87-0.96) in two independent cohorts of 160 and 141 patients, respectively. When combined with blood-based tumor markers, the integrated model further improves prediction accuracy with AUC 0.97 (0.93-0.99). Our approach to capturing dynamic information in longitudinal images may be broadly used for screening, treatment response evaluation, disease monitoring, and surveillance.


Asunto(s)
Quimioradioterapia Adyuvante/métodos , Aprendizaje Profundo , Imagen por Resonancia Magnética/métodos , Terapia Neoadyuvante/métodos , Neoplasias del Recto/diagnóstico por imagen , Biomarcadores de Tumor/sangre , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Recto/diagnóstico por imagen , Recto/patología , Resultado del Tratamiento
14.
Br J Radiol ; 94(1120): 20201215, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33710907

RESUMEN

MRI has been an essential diagnostic tool in healthcare for several decades. It offers unique insights into most tissues without the need for ionising radiation. Historically, MRI has been predominantly used qualitatively, images are formed to allow visual discrimination of tissues types and pathologies, rather than providing quantitative measurements. Increasingly, quantitative MRI (qMRI) is also finding clinical application, where images provide the basis for physical measurements of, e.g. tissue volume measures and represent aspects of tissue composition and microstructure. This article reviews some common current research and clinical applications of qMRI from the perspective of measurement science. qMRI not only offers additional information for radiologists, but also the opportunity for improved harmonisation and calibration between scanners and as such it is well-suited to large-scale investigations such as clinical trials and longitudinal studies. Realising these benefits, however, presents a new kind of technical challenge to MRI practioners. When measuring a parameter quantitatively, it is crucial that the reliability and reproducibility of the technique are well understood. Strictly speaking, a numerical result of a measurement is meaningless unless it is accompanied by a description of the associated measurement uncertainty. It is therefore necessary to produce not just estimates of physical properties in a quantitative image, but also their associated uncertainties. As the process of determining a physical property from the raw MR signal is complicated and multistep, estimation of uncertainty is challenging and there are many aspects of the MRI process that require validation. With the clinical implementation of qMRI techniques and its continued expansion, there is a clear and urgent need for metrology in this field.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/normas , Estudios de Evaluación como Asunto , Humanos , Reproducibilidad de los Resultados
15.
Br J Radiol ; 94(1120): 20201249, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33733811

RESUMEN

OBJECTIVE: To compare left ventricular (LV) and right ventricular (RV) volume, function, and image quality of a respiratory-triggered two-dimensional (2D)-cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling (2D kat-ARC) with those of the standard reference, namely, breath-hold 2D balanced steady-state free precession (2D SSFP), in patients with repaired tetralogy of Fallot (TOF). METHODS: 30 patients (14 males, mean age 32.2 ± 13.9 years) underwent cardiac magnetic resonance, and 2D kat-ARC and 2D SSFP images were acquired on short-axis view. Biventricular end-diastolic volume (EDV) and end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass (LVM) were analysed. RESULTS: The 2D kat-ARC had significantly shorter scan time (35.2 ± 9.1 s vs 80.4 ± 16.7 s; p < 0.0001). Despite an analysis of image quality showed significant impairment using 2D kat-ARC compared to 2D SSFP cine (p < 0.0001), the two sequences demonstrated no significant difference in terms of biventricular EDV, LVESV, LVSV, LVEF, and LVM. However, the RVESV was overestimated for 2D kat-ARC compared with that for 2D SSFP (73.8 ± 43.2 ml vs 70.3 ± 44.5 ml, p = 0.0002) and the RVSV and RVEF were underestimated (RVSV = 46.2±20.5 ml vs 49.4 ± 20.4 ml, p = 0.0024; RVEF = 40.2±12.7% vs. 43.5±14.0%, p = 0.0002). CONCLUSION: Respiratory-triggered 2D kat-ARC cine is a reliable technique that could be used in the evaluation of LV volumes and function. ADVANCES IN KNOWLEDGE: 2D cine kat-ARC is a reliable technique for the assessment LV volume and function in patients with repaired TOF.


Asunto(s)
Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Complicaciones Posoperatorias/diagnóstico por imagen , Tetralogía de Fallot/cirugía , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Derecha/diagnóstico por imagen , Adulto , Contencion de la Respiración , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Complicaciones Posoperatorias/fisiopatología , Reproducibilidad de los Resultados , Volumen Sistólico , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Derecha/fisiopatología
16.
Br J Radiol ; 94(1120): 20200682, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33733812

RESUMEN

OBJECTIVE: To assess intra- and inter-reader variability of apparent diffusion coefficient (ADC) and fat fraction (FF) measurement in focal myeloma bone lesions and the influence of lesion size. METHODS: 22 myeloma patients with focal active disease on whole body MRI were included. Two readers outlined a small (5-10 mm) and large lesion (>10 mm) in each subject on derived ADC and FF maps; one reader performed this twice. Intra- and inter-reader agreement for small and large lesion groups were calculated for derived statistics from each map using within-subject standard deviation, coefficient of variation, interclass correlation coefficient measures, and visualized with Bland-Altman plots. RESULTS: For mean ADC, intra- and inter-reader repeatability demonstrated equivalently low coefficient of variation (3.0-3.6%) and excellent interclass correlation coefficient (0.975-0.982) for both small and large lesions. For mean FF, intra- and inter-reader repeatability was significantly poorer for small lesions compared to large lesions (intra-reader within-subject standard variation estimate is 2.7 times higher for small lesions than large lesions (p = 0.0071), and for inter-reader variations is 3.8 times higher (p = 0.0070)). CONCLUSION: There is excellent intra- and inter-reader agreement for mean ADC estimates, even for lesions as small as 5 mm. For FF measurements, there is a significant increase in coefficient of variation for smaller lesions, suggesting lesions >10 mm should be selected for lesion FF measurement. ADVANCES IN KNOWLEDGE: ADC measurements of focal myeloma have excellent intra- and inter-reader agreement. FF measurements are more susceptible to lesion size as intra- and inter-reader agreement is significantly impaired in lesions less than 10 mm.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Mieloma Múltiple/diagnóstico por imagen , Imagen de Cuerpo Entero/métodos , Tejido Adiposo/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Proyectos Piloto , Reproducibilidad de los Resultados
17.
Br J Radiol ; 94(1120): 20200990, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33733819

RESUMEN

OBJECTIVES: Abnormal neuronal activity and functional connectivity have been reported in patients with venous pulsatile tinnitus (PT). As neuronal activity is closely coupled to regional brain perfusion, the purpose of this study was to investigate the cerebral blood flow (CBF) alterations in patients with unilateral venous PT using arterial spin labeling (ASL). METHODS: This study included patients with right-sided PT between January 2018 and July 2019. A healthy control (HC) group matched 1:1 for gender and age was also recruited. All subjects underwent ASL scanning using 3.0T MRI. The correlation between altered CBF and Tinnitus Handicap Inventory (THI) score as well as PT duration was analyzed. RESULTS: Twenty-one patients with right-sided PT and 21 HCs were included. The mean PT duration of the patients was 35.9 ± 32.2 months, and the mean THI score was 64.1 ± 20.3. Compared with the HCs, the PT patients exhibited increased CBF in the left inferior parietal gyrus and decreased CBF in the bilateral lingual gyrus (family-wise error corrected, p < 0.05). The increased CBF in the left inferior parietal gyrus showed a positive correlation with the THI score in PT patients (r = 0.501, p = 0.021). CONCLUSIONS: PT patients exhibit regional CBF alterations. The increased CBF in the left inferior parietal gyrus may reflect the severity of PT. ADVANCES IN KNOWLEDGE: This study not only presents evidence for the potential neuropathology of PT from the perspective of CBF alterations but also offers a new method for investigating the neuropathological mechanism of PT.


Asunto(s)
Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Imagen por Resonancia Magnética/métodos , Acúfeno/fisiopatología , Adulto , Encéfalo/fisiopatología , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino , Índice de Severidad de la Enfermedad , Marcadores de Spin , Tiempo
18.
Clin Nutr ESPEN ; 42: 233-238, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33745585

RESUMEN

BACKGROUND: Paediatric Crohn's disease (CD) has been associated with undernutrition. Accurate and accessible measures of body composition would provide data to personalise nutritional therapy. We assessed feasibility of MRI-derived measures of psoas cross-sectional area (PCSA) in paediatric CD and correlated with anthropometric and bioelectrical impedance spectroscopy (BIS) measures. METHODS: MRI small bowel/pelvis images of patients with CD, aged <18 years, were retrieved. Patients with concurrent anthropometric and BIS measurements were eligible for inclusion. The PCSA at L3 was calculated by two assessors and combined. To assess reproducibility of measures we calculated the coefficient of variation (CoV). Age, height-Z-scores, weight-Z-scores and BIS measures were correlated with PCSA. Using normal paediatric data from CT-scans we derived psoas area Z-scores for our cohort. RESULTS: 10 patients were included. Mean age at MRI scan was 14.6 years (11.7-16.3). PCSA was calculated for all MRI scans. There was high reproducibility between measurers, mean CoV 0.099. There was a significant positive correlation between PCSA and BIA-derived fat free mass, Pearson correlation coefficient (PCC) 0.831, p = 0.003. Correlation coefficients for PCSA and Height-for-age Z-score, weight-for-age -Z-score and age were PCC 0.343- p = 0.33, PCC = 0.222- p = 0.54, and PCC 0.6034- p = 0.065, respectively. The mean PCSA Z-score was -1.81, with 70% of the patients having a Z-score < -2.0. CONCLUSIONS: These data demonstrate the feasibility of deriving measures of body composition from routine MRI imagine. There was significant positive correlation between PCSA and BIS-derived lean mass. Further studies are required to confirm applicability of normal ranges prior to routine clinical implementation.


Asunto(s)
Enfermedad de Crohn/diagnóstico por imagen , Espectroscopía Dieléctrica/métodos , Impedancia Eléctrica , Imagen por Resonancia Magnética/métodos , Músculos Psoas/diagnóstico por imagen , Adolescente , Antropometría/métodos , Composición Corporal , Peso Corporal , Niño , Femenino , Humanos , Masculino , Evaluación Nutricional , Pelvis , Reproducibilidad de los Resultados
19.
Medicine (Baltimore) ; 100(8): e24955, 2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33663135

RESUMEN

ABSTRACT: To investigate the feasibility of arterial spin labeling (ASL) blood flow (BF) and its histogram analysis to distinguish early-stage nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPLH).Sixty-three stage T1 NPC patients and benign NPLH patients underwent ASL on a 3.0-T magnetic resonance imaging system. BF histogram parameters were derived automatically, including the mean, median, maximum, minimum, kurtosis, skewness, and variance. Absolute values were obtained for skewness and kurtosis (absolute value of skewness [AVS] and absolute value of kurtosis [AVK], respectively). The Mann-Whitney U test, receiver operating characteristic curve, and multiple logistic regression models were used for statistical analysis.The mean, maximum, and variance of ASL BF values were significantly higher in early-stage NPC than in NPLH (all P < 0.0001), while the median and AVK values of early-stage NPC were also significantly higher than those of NPLH (all P < 0.001). No significant difference was found between the minimum and AVS values in early-stage NPC compared with NPLH (P = 0.125 and P = 0.084, respectively). The area under the curve (AUC) of the maximum was significantly higher than those of the mean and median (P < 0.05). The AUC of variance was significantly higher than those of the other parameters (all P < 0.05). Multivariate analysis showed that variance was the only independent predictor of outcome (P < 0.05).ASL BF and its histogram analysis could distinguish early-stage NPC from NPLH, and the variance value was a unique independent predictor.


Asunto(s)
Circulación Cerebrovascular , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Carcinoma Nasofaríngeo/diagnóstico por imagen , Estudios de Casos y Controles , Detección Precoz del Cáncer/métodos , Estudios de Factibilidad , Femenino , Humanos , Hiperplasia/diagnóstico por imagen , Enfermedades Linfáticas/diagnóstico por imagen , Masculino , Estudios Prospectivos , Curva ROC , Sensibilidad y Especificidad
20.
BMJ Case Rep ; 14(3)2021 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-33653852

RESUMEN

The COVID-19 pandemic has dealt a devastating blow to healthcare systems globally. Approximately 3.2% of patients infected with COVID-19 require invasive ventilation during the course of the illness. Within this population, 25% of patients are affected with neurological manifestations. Among those who are affected by severe neurological manifestations, some may have acute cerebrovascular complications (5%), impaired consciousness (15%) or exhibit skeletal muscle hypokinesis (20%). The cause of the severe cognitive impairment and hypokinesis is unknown at this time. Potential causes include COVID-19 viral encephalopathy, toxic metabolic encephalopathy, post-intensive care unit syndrome and cerebrovascular pathology. We present a case of a 60 year old patient who sustained a prolonged hospitalization with COVID-19, had a cerebrovascular event and developed a persistent unexplained encephalopathy along with a hypokinetic state. He was treated successfully with modafinil and carbidopa/levodopa showing clinical improvement within 3-7 days and ultimately was able to successfully discharge home.


Asunto(s)
Encefalopatías , Carbidopa/administración & dosificación , Hipocinesia , Levodopa/administración & dosificación , Modafinilo/administración & dosificación , Rehabilitación/métodos , /aislamiento & purificación , Coagulación Sanguínea , Encefalopatías/fisiopatología , Encefalopatías/virología , /complicaciones , /terapia , Estimulantes del Sistema Nervioso Central/administración & dosificación , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etiología , Cuidados Críticos/métodos , Combinación de Medicamentos , Humanos , Hipocinesia/diagnóstico , Hipocinesia/etiología , Hipocinesia/terapia , /etiología , /terapia , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Respiración Artificial/métodos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Desconexión del Ventilador/métodos
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