Fusión de datos multimodales de neurociencias generados en estudios EEG-fMRI, un análisis temático / Fusion of Multimodal Neuroscience Data Generated in EEG-fMRI Studies, a Thematic Analysis

La actividad cerebral tiene múltiples atributos, entre ellos los eléctricos, metabólicos, hemodinámicos y hormonales. Los métodos modernos para estudiar las funciones cerebrales como el PET (Tomografía por Emisión de Positrones), fMRI (Imagen de Resonancia Magnética Funcional) y MEG (Magnetoencefalograma) son ampliamente utilizados por los científicos. Sin embargo, el EEG es una herramienta utilizada para la investigación y diagnóstico debido a su bajo costo, simplicidad de uso, movilidad y la posibilidad de monitoreo a largo tiempo de adquisición. Para detectar e interpretar las características relevantes de estas señales, se describe cada proceso por su escala temporal (EEG) y espacial (fMRI). La presente investigación se enfoca en realizar una revisión bibliográfica sobre la integración de datos multimodales EEG-fMRI que propicie valorar su importancia para el desarrollo de algoritmos de fusión y su uso en el contexto cubano. Para ello se analizaron documentos con altos índices de citas en la literatura, donde se destacan autores precursores de los temas en análisis. Los estudios multimodales EEG-fMRI generan múltiples datos temporales y espaciales con alto valor para la medicina basada en evidencia. La integración de los mismos provee un valor agregado en la búsqueda de nuevos métodos diagnósticos, aplicando minería de datos, Deep learning y algoritmos de fusión. En este trabajo se pone de relieve la existencia de baja resolución temporal de fMRI y por otro lado la baja resolución espacial de EEG, por lo que la integración de ambos estudios aumentaría la calidad de su información(AU)

Brain activity has multiple attributes, including electrical, metabolic, hemodynamic, and hormonal. Modern methods for studying brain functions such as PET (Positron Emission Tomography), fMRI (Functional Magnetic Resonance Imaging), and MEG (Magnetoencephalogram) are widely used by scientists. However, the EEG is a tool used for research and diagnosis due to its low cost, simplicity of use, mobility and the possibility of long-term monitoring of acquisition. To detect and interpret the relevant characteristics of these signals, each process is described by its temporal (EEG) and spatial (fMRI) scale. The present research focuses on conducting a bibliographic review on the integration of multimodal EEG-fMRI data that favors assessing its importance for the development of fusion algorithms and their use in the Cuban context. For this, documents with high rates of citations in the literature were analyzed, where precursor authors of the topics under analysis stand out. Multimodal EEG-fMRI studies generate multiple temporal and spatial data with high value for evidence-based medicine. Their integration provides added value in the search for new diagnostic methods, applying data mining, Deep learning and fusion algorithms. This work highlights the existence of low temporal resolution of fMRI and, on the other hand, the low spatial resolution of EEG, so the integration of both studies would increase the quality of their information(AU)

Linfoma cardíaco primário: o papel da multimodalidade de imagem na abordagem diagnóstica / Primary cardiac lymphoma: role of imaging multimodality in diagnosis

Massas intracardíacas constituem um desafio diagnóstico, já que os sintomas são comuns a patologias cardiovasculares ou não. Métodos ­ invasivos ou não ­ possibilitam o diagnóstico diferencial e a confirmação histológica, propiciando tratamento adequado. Para melhor compreender a importância da multimodalidade em imagem e a abordagem nos tumores cardíacos , relatamos o caso de um lifoma cardíaco primário, em que a abordagem multidisciplinar permitiu o rápido diagnóstico e seu tratamento, inclusive das intercorrências, com resposta inicial promissora, a despeito da evolução fatal durante a pandemia por SARS-CoV-2.(AU)

Intracardiac masses are a diagnostic challenge since their symptoms can be common to cardiovascular pathologies. Some methods, whether invasive or not, enable differential diagnosis, histological confirmation, and adequate treatment. To better understand the importance of imaging multimodality and the approach to managing cardiac tumors, we investigated a case of a primary cardiac lymphoma in which the multidisciplinary approach allowed rapid diagnosis and treatment, including of intercurrences, with a promising initial response despite fatal progression due to severe acute respiratory syndrome coronavirus 2 infection. (AU)

Multimodal imaging analysis of the cyst like lesion of condyle in temporomandibular joint / 中华口腔医学杂志

Objective: To investigate the imaging features of condylar cystic degeneration of temporomandibular joint (TMJ) by cone-beam CT (CBCT), spiral CT, MRI and radionuclide bone imaging. Methods: From January 2018 to December 2020, thirty-two patients with cyst-like lesions of condylein temporomandibular joint were examined by CBCT, spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 12 males and 20 females involved, aged from 16 to 65 years with an average age of (33.9±12.5) years. The characteristics of CBCT, spiral CT, MRI and radionuclide bone imaging were analyzed. Condylar cyst like lesions were classified as type A and type B based on the presence or absence of surface bone defects. Condylar cyst like lesions were classified as type Ⅰ(yes) and type Ⅱ(no) according to the accompanying bone marrow edema-like lesions of the condyles. The incidence of condylar bone marrow edema, disc displacement and abnormal bone metabolism were analyzed. Results: A total of 64 joint images of 32 patients were included, including 34 sides with TMJ cyst-like lesion and 6 sides with multiple cyst-like lesions,the total cyst-like lesions were 42. The largest diameter of cyst-like lesion ranged from 1.0 to 12.4 mm, with an average length of (3.7± 1.8) mm. There were 24 cases of type A TMJ cyst like lesion and 10 cases of type B cyst-like lesion. The detection rate of CBCT was 95.2% (40/42) and that of spiral CT was 100% (42/42), there was no significant difference (Calibration Chi-square=0.51, P=0.474). The detection rate of nuclear magnetic resonance was 80.1% (34/42), and the detection rate of cyst-like lesions less than 2 mm was 3/11. In the cyst like lesion side, there were 9 sides with anterior disc displacement with reduction, 20 sides with anterior disc displacement without reduction. In the non-cyst like lesion side, 10 sides with anterior disc displacement with reduction and 6 sides with anterior disc displacement without reduction. There was a significant difference in the displacement of the disc between cyst-like and non-cystic lesion side (χ²=7.80, P=0.005). MRI showed that 6 cases of cystic side[17.6% (6/34)] had bone marrow edema-like lesions (all type A), 1 case of non-cyst like lesions side [3.3% (1/30)] had bone marrow edema-like lesion, there was no significant difference between cystic and non-cystic lesions (Calibration Chi-square=2.04, P=0.153). There was a significant difference between type A and B cystic lesions (Fisher exact probability method, P=0.024). Radionuclide bone imaging showed abnormal bone metabolism in 26 patients in the cyst-like lesion side and 5 patients in the non-cyst like lesion side (χ²=22.82, P<0.001). Conclusions Multi-slice Spiral CT could detect the cyst-like lesion of TMJ condyle in the early stage, which is different from the large joint. And the formation mechanism may vary from the different classifications.

The correlation between metabolic parameters in (18)F-FDG PET-CT and solid and micropapillary histological subtypes in lung adenocarcinoma / 中华肿瘤杂志

Objective: Solid and micropapillary pattern are highly invasive histologic subtypes in lung adenocarcinoma and are associated with poor prognosis while the biopsy sample is not enough for the accurate histological diagnosis. This study aims to assess the correlation and predictive efficacy between metabolic parameters in (18)F-fluorodeoxy glucose positron emission tomography/computed tomography ((18)F-FDG PET-CT), including the maximum SUV (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and solid and micropapillary histological subtypes in lung adenocarcinoma. Methods: A total of 145 resected lung adenocarcinomas were included. The clinical data and preoperative (18)F-FDG PET-CT data were retrospectively analyzed. Mann-Whitney U test was used for the comparison of the metabolic parameters between solid and micropapillary subtype group and other subtypes group. Receiver operating characteristic (ROC) curve and areas under curve (AUC) were used for evaluating the prediction efficacy of metabolic parameters for solid or micropapillary patterns. Univariate and multivariate analyses were conducted to determine the prediction factors of the presence of solid or micropapillary subtypes. Results: Median SUV(max) and TLG in solid and papillary predominant subtypes group (15.07 and 34.98, respectively) were significantly higher than those in other subtypes predominant group (6.03 and 10.16, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for prediction of solid and micropapillary predominant subtypes [AUC=0.811(95% CI: 0.715~0.907) and 0.725(95% CI: 0.610~0.840), P<0.05]. Median SUV(max) and TLG in lung adenocarcinoma with the solid or micropapillary patterns (11.58 and 22.81, respectively) were significantly higher than those in tumors without solid and micropapillary patterns (4.27 and 6.33, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for predicting the presence of solid or micropapillary patterns [AUC=0.757(95% CI: 0.679~0.834) and 0.681(95% CI: 0.595~0.768), P<0.005]. Multivariate logistic analysis showed that the clinical stage (Stage Ⅲ-Ⅳ), SUV(max) ≥10.27 and TLG≥7.12 were the independent predictive factors of the presence of solid or micropapillary patterns (P<0.05). Conclusions: Preoperative SUV(max) and TLG of lung adenocarcinoma have good prediction efficacy for the presence of solid or micropapillary patterns, especially for the solid and micropapillary predominant subtypes and are independent factors of the presence of solid or micropapillary patterns.

Punctate inner choroidopathy with atypical presentation / Coroidopatia interna ponteada de apresentação atípica

ABSTRACT We report a case of a young Caucasian female presenting with sudden decrease of vision in the left eye, metamorphopsia, and nasal scotoma. Past medical history revealed a diagnosis of myasthenia gravis, which was currently treated with azathioprine, pyridostigmine, and prednisone. Ophthalmological examination showed fundus with clear vitreous and yellow-white lesions that were isolated and perimacular in the right eye, multiple and confluent in the macula, and punctate in periphery in the left eye. Laboratory workup ruled out the presence of infectious and inflammatory diseases. Fundus autofluorescence disclosed hypoautoflurescence with hyperfluorescent margins corresponding to the lesions observed in both eyes and the angiogram revealed hyperfluorescence since early phases without late leakage. Spectral-domain optical coherence tomography showed areas of intermittent retinal pigment epithelium elevations and disruption of the ellipsoid zone. She was diagnosed with punctate inner choroidopathy and then treated with an increased dose of daily prednisone, which resulted in progressive improvement of her visual acuity and anatomical status.(AU)

RESUMO Relato de caso de mulher jovem, caucasiana, com súbita diminuição de acuidade visual de olho esquerdo, metamorfopsia e escotoma nasal. Apresentava diagnóstico de Miastenia gravis, em tratamento com Azatioprina, Piridostigmina e Prednisona. Fundo de olho demonstrava vítreo límpido e lesões amarelo-esbranquiçadas, perimaculares e isoladas em olho direito, múltiplas e confluentes em mácula e pontilhadas em periferia no olho esquerdo. Exames laboratoriais descartaram doenças infecciosas e inflamatórias. Auto-fluorescência revelou lesões hipoautofluorescentes com margens hiperfluorescentes correspondentes às observadas em ambos os olhos, enquanto angiofluoresceinografia mostrou hiperfluorescência desde as fases iniciais sem vazamento tardio. Tomografia de coerência óptica de domínio espectral revelou áreas de elevações intermitentes do epitélio pigmentar da retina e interrupção da zona elipsóide correspondente. Definiu-se como diagnóstico a coroidopatia interna ponteada, sendo instituído aumento na dose diária de Prednisona, com melhoria progressiva da acuidade visual e do aspecto de fundo de olho da paciente.(AU)

Un caso clínico de implante valve in valve mitral: nuevo horizonte en el tratamiento de la disfunción valvular protésica / A clinical case of mitral valve in valve implant: new skyline in the treatment of prosthetic valve dysfunction / Presentação de um caso clínico do valve in valve mitral: um novo horizonte no tratamento da disfunção valvular protética

La disfunción valvular protésica es cada vez más frecuente debido al envejecimiento de la población portadora de bioprótesis y se presenta como un desafío en el momento de su diagnóstico, valoración y tratamiento. Aplicar un enfoque imagenológico multimodal es fundamental para su manejo. Respecto al tratamiento, surge como nueva alternativa un procedimiento mínimamente invasivo de sustitución valvular percutánea, denominado valve in valve, principalmente en pacientes con riesgo quirúrgico elevado. Presentamos uno de los primeros casos locales de implante percutáneo de prótesis mitral transeptal dentro de una bioprótesis mitral quirúrgica disfuncionante.

Prosthetic valve dysfunction is increasingly common due to the aging of the bioprosthesis-bearing population, and it presents a challenge at the time of diagnosis, evaluation, and treatment. A multimodal imaging approach is essential for its management. In relation to treatment, a minimally invasive percutaneous valve replacement procedure called valve in valve arises as a new alternative, mainly in patients with high surgical risk. We present one of first local cases of percutaneous implantation of a transseptal mitral prosthesis within a dysfunctional surgical mitral bioprosthesis.

A disfunção valvular protética é cada vez mais comum devido ao envelhecimento da população portadora de biopróteses e representa um desafio no momento do diagnóstico, avaliação e tratamento. A multimodalidade da imagem cardiovascular é essencial para sua avaliação. Em relação ao tratamento, um procedimento de troca valvular percutânea minimamente invasivo, denominado valve in valve, surge como uma nova alternativa, principalmente em pacientes com alto risco cirúrgico. Apresentamos um dos primeiros casos realizados no Uruguai de implantação percutânea de prótese mitral transeptal dentro de bioprótese mitral cirúrgica disfuncional.

Cuando no todo es lo que parece_: masa extracardíaca en la aurícula izquierda: reporte de un caso en Uruguay / When not everything is what it seems_: extra-cardiac mass in the left atrium: a case report in Uruguay / Quando nem tudo é o que parece_: massa extracardíaca em átrio esquerdo: relato de um caso no Uruguai

La hernia hiatal es una entidad relativamente frecuente y puede ser un hallazgo incidental en un estudio ecocardiográfico. Describimos el caso de una paciente con diagnóstico de masa en la aurícula izquierda (AI) sin clara etiología, a quien se le realiza el diagnóstico de hernia hiatal por resonancia magnética cardíaca (RMC) y luego se demuestra mediante ecocardiografía de contraste el contenido gástrico de la masa tras la ingestión de una bebida carbonatada, lo que permite de forma rápida y sencilla aclarar el diagnóstico.

Hiatal hernia is a relatively common entity, and may be an incidental finding in an echocardiographic study. We describe the case of a patient with a diagnosis of a mass in the left atrium with no clear etiology, in whom the diagnosis of hiatal hernia is made by cardiac magnetic resonance imaging and then demonstrated by contrast echocardiography the gastric content of the mass after the ingestion of a carbonated drink, which allows quickly and easily to clarify the diagnosis.

A hérnia de hiato é uma entidade relativamente comum, e pode ser um achado incidental em um estudo ecocardiográfico. Descrevemos o caso de um paciente com diagnóstico de massa em átrio esquerdo sem etiologia definida, em que o diagnóstico de hérnia de hiato é feito por ressonância magnética cardíaca e posteriormente demonstrado por ecocardiografia contrastada com uma bebida gaseificada, permitindo esclarecer de forma rápida e fácil o diagnóstico.

Supradesnivel del segmento ST como forma de presentación atípica de un tumor cardíaco: rol diagnóstico de la multimodalidad de imagen / ST segment elevation as an atypical presentation of a cardiac tumor: diagnostic role of a multimodal imaging approach / Elevação do segmento ST como apresentação de tumor cardíaco: papel diagnóstico da multimodalidade de imagem

Los tumores cardíacos malignos son neoplasias poco frecuentes que pueden presentarse de diversas formas, lo que dificulta su diagnóstico. La ecocardiografía y la resonancia magnética cardíaca son técnicas fundamentales para el diagnóstico, la caracterización y la evaluación de su extensión tumoral. La identificación de la línea tumoral es esencial al iniciar un tratamiento oncológico dirigido. Si bien el "estándar de oro" para este fin es el estudio anatomopatológico (obtenido por biopsia o resección quirúrgica), en los casos en que esto no es posible, la resonancia magnética cardíaca es la técnica no invasiva que proporciona un mejor abordaje diagnóstico. El tratamiento de elección es la resección quirúrgica y el pronóstico, en general, es malo. Presentamos el caso de una paciente con un tumor cardíaco de presentación clínica atípica, en la que un abordaje imagenológico multimodal aporta información clave y complementaria para el diagnóstico y la caracterización tisular.

Malignant cardiac tumors are rare neoplasms that can present in various forms, making their diagnosis difficult. Echocardiography and cardiac magnetic resonance imaging are fundamental techniques for the diagnosis, characterization, and evaluation of tumor extension. Identification of the tumor line is essential when initiating targeted cancer therapy. Although the "gold standard" for this purpose is the pathological study (obtained by biopsy or surgical resection), in cases where this is not possible, cardiac resonance is the non-invasive technique that provides a better diagnostic approach. The treatment of choice is surgical resection and the prognosis is generally poor. We present the case of a patient with an atypical clinical presentation, in which a multimodal approach provides key and complementary information for tumor diagnosis and tissue characterization.

Os tumores cardíacos malignos são neoplasias raras que podem se apresentar de várias formas, dificultando seu diagnóstico. A ecocardiografia e a ressonância magnética cardíaca são técnicas fundamentais para o diagnóstico, caracterização e avaliação da extensão tumoral. A identificação da linha do tumor é essencial ao iniciar a terapia direcionada do câncer. Embora o "padrão ouro" para esse fim seja o estudo patológico (obtido por biópsia ou ressecção cirúrgica), nos casos em que isso não seja possível, a ressonância cardíaca é a técnica não invasiva que proporciona melhor abordagem diagnóstica. O tratamento de escolha é a ressecção cirúrgica e o pronóstico geralmente é ruim. Apresentamos o caso de uma paciente com apresentação clínica atípica, em que a abordagem multimodal fornece informações essenciais e complementares para o diagnóstico do tumor e caracterização do tecido.

A review on cardiac positron emission tomography/magnetic resonance imaging in diagnosis of cardivascular diseases / 生物医学工程学杂志

There are various examination methods for cardiovascular diseases. Non-invasive diagnosis and prognostic information acquisition are the current research hotspots of related imaging examinations. Positron emission tomography (PET)/magnetic resonance imaging (MRI) is a new advanced fusion imaging technology that combines the molecular imaging of PET with the soft tissue contrast function of MRI to achieve their complementary advantages. This article briefly introduces several major aspects of cardiac PET/MRI in the diagnosis of cardiovascular disease, including atherosclerosis, ischemic cardiomyopathy, nodular heart disease, and myocardial amyloidosis, in order to promote cardiac PET/MRI to be more widely used in precision medicine in this field.

Neuroimaging and electroencephalographic (EEG) methods for investigating neural circuits in mental disorders / Métodos de neuroimagem e eletroencefalografia (EEG) para investigação de circuitos neurais em transtornos mentais

It is increasingly recognised that dysfunction in neural circuits plays a key role in the neurobiological basis of mental disorders. The efficacy of pharmacological and behavioural treatments for mental disorders could therefore be improved by targeting dysfunctions in neurocircuits. However, to achieve this, a better understanding of the specific alterations in neural circuits involved in different mental disorders is required. Such understanding can be acquired by using advanced neuroscience methods to examine the pathways and function of neurocircuits in both typically developing individuals and in those with mental disorders. This article provides an overview of currently available neuroscience methods of investigating neural circuits, including advantages and limitations of different techniques, and highlights the importance of using multi-modal imaging in future research.

É cada vez mais reconhecido que a disfunção nos circuitos neurais desempenha um papel fundamental na base neurobiológica dos transtornos mentais. A eficácia dos tratamentos farmacológicos e comportamentais para os transtornos mentais pode, portanto, ser melhorada por direcionar as disfunções nos neurocircuitos. No entanto, para isso, é necessário um melhor entendimento das alterações específicas nos circuitos neurais envolvidos em diferentes transtornos mentais. Tal entendimento pode ser adquirido usando-se métodos avançados de neurociência para examinar as vias e a função dos neurocircuitos em indivíduos com desenvolvimento típico e naqueles com transtornos mentais. Este artigo fornece uma visão geral dos métodos da neurociência atualmente disponíveis na investigação de circuitos neurais, incluindo vantagens e limitações de diferentes técnicas, e destaca a importância do uso de imagens multimodais em pesquisas futuras.

Imaging description of extragenital müllerian adenosarcoma: A case report / Descrição da imagem do adenosarcoma mülleriano extragenital: relato de caso

Abstract Müllerian adenosarcoma is a very rare gynecological disease, comprising 5% of uterine sarcomas. Extragenital localizations are even rarer.We report a very interesting case of a 27-year-old woman complaining of pelvic pain, with a subsequent diagnosis of extragenital Müllerian adenosarcoma. This is the first case reported in the literature with a complete and wide imaging description. Even if rare, Müllerian adenosarcoma should be hypothesized in case of young female patients presenting with suspicious pelvic mass.

Resumo O adenosarcoma Mülleriano é uma doença ginecológica muito rara, compreendendo 5% dos sarcomas uterinos. Localizações extragenitais são ainda mais raras. Relatamos um caso muito interessante de uma mulher de 27 anos queixando-se de dor pélvica com diagnóstico subsequente de adenosarcoma Mülleriano extragenital. Este é o primeiro caso relatado na literatura com uma descrição completa e ampla de imagem. Mesmo que raro, o adenosarcoma Mülleriano deve ser hipotetizado no caso de pacientes jovens do sexo feminino com massa pélvica suspeita.

Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions

OBJECTIVES: Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS: A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS: In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION: Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors. METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Design and implementation of postoperative evaluation pipeline of deep brain stimulation by multimodality imaging / 生物医学工程学杂志

Deep brain stimulation (DBS) surgery is an important treatment for patients with Parkinson's disease in the middle and late stages. The accuracy of the implantation of electrode at the location of the nuclei directly determines the therapeutic effect of the operation. At present, there is no single imaging method that can obtain images with electrodes, nuclei and their positional relationship. In addition, the subthalamic nucleus is small in size and the boundary is not obvious, so it cannot be directly segmented. In this paper, a complete end-to-end DBS effect evaluation pipeline was constructed using magnetic resonance (MR) data of T1, T2 and SWI weighted by DBS surgery. Firstly, the images of preoperative and postoperative patients are registered and normalized to the same coordinate space. Secondly, the patient map is obtained by non-rigid registration of brain map and preoperative data, as well as the preoperative nuclear cluster prediction position. Then, a three-dimensional (3D) image of the positional relationship between the electrode and the nucleus is obtained by using the electrode path in the postoperative image and the result of the nuclear segmentation. The 3D image is helpful for the evaluation of the postoperative effect of DBS and provides effective information for postoperative program control. After analysis, the algorithm can achieve a good registration between the patient's DBS surgical image and the brain map. The error between the algorithm and the expert evaluation of the physical coordinates of the center of the thalamus is (1.590 ± 1.063) mm. The problem of postoperative evaluation of the placement of DBS surgical electrodes is solved.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors.METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors.RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images.CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Timing calibration comparison research of integrated TOF-PET/MR / 生物医学工程学杂志

Integrated TOF-PET/MR is a multimodal imaging system which can acquire high-quality magnetic resonance (MR) and positron emission tomography (PET) images at the same time, and it has time of flight (TOF) function. The TOF-PET system usually features better image quality compared to traditional PET because it is capable of localizing the lesion on the line of response where annihilation takes place. TOF technology measures the time difference between the detectors on which the two 180-degrees-seperated photons generated from positron annihilation are received. Since every individual crystal might be prone to its timing bias, timing calibration is needed for a TOF-PET system to work properly. Three approaches of timing calibration are introduced in this article. The first one named as fan-beam method is an iterative method that measures the bias of the Gaussian distribution of timing offset created from a fan-beam area constructed using geometric techniques. The second one is to find solutions of the overdetermination equations set using L1 norm minimization and is called L1-norm method. The last one called L2-norm method is to build histogram of the TOF and find the peak, and uses L2 norm minimization to get the result. This article focuses on the comparison of the amount of the data and the calculation time needed by each of the three methods. To avoid location error of the cylinder radioactive source during data collection, we developed a location calibration algorithm which could calculate accurate position of the source and reduce image artifacts. The experiment results indicate that the three approaches introduced in this article could enhance the qualities of PET images and standardized uptake values of cancer regions, so the timing calibration of integrated TOF-PET/MR system was realized. The fan-beam method has the best image quality, especially in small lesions. In integrated TOF-PET/MR timing calibration, we recommend using fan-beam method.

Multimodal image fusion technology for diagnosis and treatment of the skull base-infratemporal tumors / 北京大学学报(医学版)

OBJECTIVE@#To explore the value of incorporated multimodal image fusion technology with computer-aided design of the skull base-infratemporal tumor treatment.@*METHODS@#A retrospective study was carried out to enroll seventeen patients with skull base-infratemporal tumors treated at Peking University Hospital of Stomatology from February 2011 to September 2018. Plain CT, enhanced CT and MRI data were imported into the iPlan 3.0 software (BrainLab navigation system), and the image fusion was performed for each patient preoperatively. Then the three-dimensional images of the tumor, vital vessels and craniofacial bones were reconstructed to prepare virtual operation design. We evaluated the application of multimodal image fusion technology that had been incorporated with computer-aided planning during the navigation-guided biopsy or surgery, through the analysis of the biopsy and operation data and regular follow-up postoperatively.@*RESULTS@#The mean age of 17 patients (7 males and 10 females) was 46 years. Primary tumors occurred in 11 cases, and recurrent tumors in 6 cases. The size of the 17 tumors ranged from 2.9 cm to 9 cm, and the mean size was 4.35 cm. There were 7 cases with skull base bone destruction and/or intracranial extension, and 10 cases with tumors adjacent to the skull base. High-quality multimodal fused images were obtained in all the 17 cases. The spatial-position relationships of the tumors, adjacent craniomaxillofacial bones and vital vessels labeled with different colors were displayed well on the generated fusion images. The multimodal image fusion technology that incorporated with computer-aided three-dimensional reconstruction and then applied in navigation-guided biopsy or surgery showed that, preoperative analysis and virtual operation design functioned with good results, especially in cases with small tumor size, recurrence or illdefined borders in the skull base-infratemporal region. Operation was carried out in 16 cases after preoperative diagnosis and assessment, and 1 case was performed by navigation-guided biopsy only. The proportions of navigation-guided surgery and biopsy were 70.6% (12/17) and 17.6% (3/17) individually. The positive rate of pathologic diagnosis using navigation-guided biopsy was 100% (3/3). All the navigation-guided biopsies or operations were carried out successfully. Complications included 1 case of cerebrospinal fluid leak from a recurred meningioma patient postoperatively, and 1 case of facial paralysis resulting from parotid-gland deep lobe tumor. Most (14/15) tumors got complete removal with safe boundary through intra-operative navigation verification and post-operative imaging confirmation, except for one case of subtotal resection to avoid the injury of cavernous sinus. The pathological results of the tumors could be classified to mesenchymal (10), adenogenous (3), neurogenic (3) or epithelial (1) resources. The follow-up time ranged from 3 to 94 months, with the median follow-up time of 9 months.@*CONCLUSION@#Taking full advantages of individualized multimodal images, could help analyze the three-dimensional spatial position relationship of tumors, vital vessels and craniofacial bones properly, and then complete the virtual operation design well. The incorporated multimodal image fusion technology with navigation technology may improve the accuracy and safety of core needle biopsy and surgical treatment of skull base-infratemporal tumors.

Multimodal Composite Iron Oxide Nanoparticles for Biomedical Applications

BACKGROUND: Iron oxide nanoparticles (IONPs) are excellent candidates for biomedical imaging because of unique characteristics like enhanced colloidal stability and excellent in vivo biocompatibility. Over the last decade, material scientists have developed IONPs with better imaging and enhanced optical absorbance properties by tuning their sizes, shape, phases, and surface characterizations. Since IONPs could be detected with magnetic resonance imaging, various attempts have been made to combine other imaging modalities, thereby creating a high-resolution imaging platform. Composite IONPs (CIONPs) comprising IONP cores with polymeric or inorganic coatings have recently been documented as a promising modality for therapeutic applications. METHODS: In this review, we provide an overview of the recent advances in CIONPs for multimodal imaging and focus on the therapeutic applications of CIONPs. RESULTS: CIONPs with phototherapeutics, IONP-based nanoparticles are used for theranostic application via imaging guided photothermal therapy. CONCLUSION: CIONP-based nanoparticles are known for theranostic application, longstanding effects of composite NPs in in vivo systems should also be studied. Once such issues are fixed, multifunctional CIONP-based applications can be extended for theranostics of diverse medical diseases in the future.